Raw material for spray material and method for applying spray material

Abstract

To provide a raw material for a spray material which contains a fibrous aggregate as a main material and from which a construction object hardly falls off from a structure due to the own weight of the spray material even when the spray material is sprayed to the structure having no surface for supporting the spray material in a vertical direction, and to provide a construction method of the spray material using the raw material for the spray material.SOLUTION: A raw material for a spraying material contains 80-99 mass% of a granular fibrous aggregate containing a granulation binder and a powder of a binder for a spraying material, wherein the powder of a binder for a spraying material contains one or more of aluminum sulfate and polyaluminum chloride, and a method for applying a spraying material using the raw material for a spraying material is provided.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a raw material for a spraying material and a method for applying the spraying material. [Background technology]

[0002] Patent document 1 describes a fibrous aggregate for spraying materials, which is a granular aggregate containing ceramic fibers and a binder, has a compressibility index of 55% or less, an angle of repose of 58° or less, and an aggregate particle size of less than 7.0 mm. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent No. 7219957 Summary of the Invention [Problem to be solved by the invention]

[0004] Patent Document 1 describes the results of a spraying test in which a mixture of fibrous aggregate for a spraying material, carboxymethyl cellulose powder, and water was sprayed onto an object using a spraying machine.

[0005] After investigation, it was found that when the mixture is sprayed onto structures that do not have a surface to support the sprayed material in the vertical direction, such as vertical walls, overhangs with an inclination angle exceeding the vertical, ceiling surfaces, or the underside of structures such as walking beams, the sprayed material sprayed onto the object, i.e., the object to be sprayed, may collapse under its own weight.

[0006] The present invention aims to provide a raw material for spraying material that is primarily made of fibrous aggregate, and that is less likely to cause the applied product to fall off from a structure due to its own weight even when sprayed against the structure that does not have a surface to support the spraying material in a vertical direction, and a method for applying the spraying material using the raw material for spraying material. [Means for solving the problem]

[0007] The above-mentioned problem is solved by a raw material for spraying material containing 80 to 99 mass% of granular fibrous aggregate and a powder of binder for spraying material, wherein the powder of binder for spraying material contains one or more of a flocculant containing polyaluminum chloride and aluminum sulfate.

[0008] The above-mentioned problems are solved by a method for applying a spray material in which the raw material for the spray material and a liquid component are mixed in a carrier gas to form a spray material, and the spray material is then sprayed together with the carrier gas onto an object to be applied.

[0009] In the raw material for the spraying material and the method for applying the spraying material, the raw material for the spraying material may contain 0.1 to 5.1 mass % of aluminum sulfate in terms of anhydride.

[0010] In the raw material for the spraying material and the application method of the spraying material, the raw material for the spraying material may contain 0.1 to 5.1 mass % of a flocculant containing polyaluminum chloride.

[0011] In the raw material for the spraying material and the method for applying the spraying material, the fibrous aggregate preferably contains a water repellent.

[0012] In the raw material for the spraying material and the application method of the spraying material, the bulk density of the fibrous aggregate is 1.0 g / cm 3 It is preferable that:

[0013] In the method for applying the spraying material, a liquid component can be mixed in an amount 0.6 to 1.8 times the mass of the raw material for the spraying material.

[0014] In the above-described spray material application method, the object to be applied can be a structure that does not have a surface that supports the spray material in the vertical direction. [Effects of the Invention]

[0015] According to the present invention, it is possible to provide a raw material for spraying material that is primarily made of fibrous aggregate, and that is less likely to cause the applied object to fall off from a structure due to its own weight even when the spraying material is sprayed against a structure that does not have a surface to support the spraying material in a vertical direction, and a method for applying the spraying material using the raw material for spraying material. [Brief explanation of the drawings]

[0016] [Figure 1] FIG. 2 is an explanatory diagram showing an example of a spray machine. [Figure 2] FIG. 2 is an explanatory view showing a reservoir part of the spray machine of FIG. [Figure 3] 10 is a photograph showing a state of a spraying test of the raw material for the gunning material according to Example 10. [Figure 4] 1 is a photograph showing a state of a spraying test of a raw material for a gunning material according to Comparative Example 1. DETAILED DESCRIPTION OF THE INVENTION

[0017] Hereinafter, an embodiment of the present invention will be described. The present invention is a raw material for a spraying material containing 80 to 99 mass% of granular fibrous aggregate containing a granulated binder and a powder of a binder for a spraying material. The powder of the binder for a spraying material contains one or more of a flocculant containing polyaluminum chloride and aluminum sulfate. The proportion of the binder powder for a spraying material contained in the raw material for a spraying material can be, for example, 1 to 15 mass%.

[0018] The method for producing the fibrous aggregate is not particularly limited. For example, the fibrous aggregate can be produced using a ceramic fiber aggregate formed by entanglement of ceramic fibers as a raw material. The ceramic fiber aggregate is commercially available as a ceramic fiber blanket, for example.

[0019] The fibrous aggregate can be produced, for example, as follows: First, ceramic fibers are crushed in a crushing device. A granulating binder is applied to the crushed ceramic fibers, and the ceramic fibers containing the granulating binder are granulated while rolling in a granulator such as a concrete mixer. The granulated material is dried, sieved, and classified to obtain a granular fibrous aggregate. During granulation, water may be impregnated into the ceramic fibers. Furthermore, during granulation, a water repellent may be applied to the ceramic fibers before granulation or to the granulated fibrous aggregate so that the fibrous aggregate contains the water repellent.

[0020] The granulating binder may be any binder capable of shaping ceramic fibers into granules. For example, organic or inorganic binders may be used. Examples of organic binders that can be used include carboxymethyl cellulose, carboxymethyl cellulose derivatives, polyvinyl alcohol, and gum arabic. Examples of inorganic binders that can be used include montmorillonite and zeolite.

[0021] The granulation binder preferably contains carboxymethyl cellulose and / or a derivative of carboxymethyl cellulose (hereinafter, sometimes simply referred to as carboxymethyl cellulose, etc.). The action of aluminum sulfate and carboxymethyl cellulose, etc., contained in the spray material binder makes gelation, which will be described later, more likely to occur.

[0022] The content of the granulation binder is not particularly limited, but for example, the content of the granulation binder contained in the fibrous aggregate after granulation can be, for example, 0.1 to 15 mass %, or 0.1 to 5 mass %.

[0023] The water repellent may be commercially available. For example, a water repellent having a contact angle with water of 85 to 160° or 85 to 115° may be used. The contact angle is determined in accordance with JIS R 3257:1999 "Test Method for Wettability of Substrate Glass Surfaces." Known silicone resin-based water repellents or fluororesin-based water repellents may be used as the water repellent having the above contact angle. Silicone resins are compounds having siloxane bonds. Examples of silicone resins that may be used include liquid compositions containing silicone oil or modified silicone resins, and emulsions of silicone resins.

[0024] The content of the water repellent agent contained in the fibrous aggregate after granulation is not particularly limited, but can be, for example, 0.1 to 18 mass%, 0.1 to 14 mass%, or 0.1 to 3 mass%. When the water repellent agent is diluted with a solvent, the content of the water repellent agent referred to here is based on the mass of the water repellent agent or synthetic resin excluding the solvent.

[0025] By incorporating a water repellent into the fibrous aggregate, the raw material for the spraying material can be mixed with a liquid to form the spraying material, reducing the amount of liquid required to spray it onto the target object. Reducing the amount of liquid used reduces the voids remaining in the target object after the liquid evaporates, improving the strength of the target object obtained when the spraying material hardens. Furthermore, when the target object is a high-temperature furnace ceiling, for example, a decrease in furnace heat due to the use of a large amount of water can be suppressed. Furthermore, if the spraying material contains a large amount of liquid, the mass of the target object immediately after application increases depending on the amount of liquid, causing the target object to peel off. Reducing the amount of liquid can suppress peeling from the target object.

[0026] The particle size of the fibrous aggregate is not particularly limited, but can be, for example, less than 7.0 mm. The particle size of the fibrous aggregate is also not particularly limited, but can be 0.3 mm or more. The particle size here refers to the range of particle size distribution, meaning, for example, the size that falls below a sieve of a 7.0 mm mesh. By setting the particle size distribution range in this way, it is possible to suppress the phenomenon known as rebound loss, in which the fibrous aggregate rebounds without adhering to the object when sprayed onto the object, thereby improving yield and spraying efficiency. In this specification, the term "powder" refers to a particle size that includes the above aggregates.

[0027] The bulk density of the fibrous aggregate is 1.0 g / cm 3 Preferably, it is 0.75 g / cm or less. 3 By setting the bulk density in this range, it is possible to provide heat insulating properties to the construction formed by spraying the spray material. The lower limit of the bulk density is not particularly limited, but is preferably 0.1 g / cm 3 The bulk density is measured based on the tapped bulk density method in JIS R 1628-1997, 7.1.

[0028] The compressibility index of the fibrous aggregate, as determined by the method described below, is preferably 35% or less, more preferably 23% or less, and even more preferably 14% or less. The lower limit of the compressibility index of the fibrous aggregate is not particularly limited, but can be, for example, 4% or more. The angle of repose of the fibrous aggregate, as determined by the method described below, is preferably 42° or less, more preferably 35° or less. The lower limit of the angle of repose of the fibrous aggregate is not particularly limited, but can be, for example, 20° or more. The use of such fibrous aggregate improves the fluidity of the solids when supplying the raw material for the spraying material from a storage section such as a hopper, making it less likely that ratholes or bridges will form in the raw material for the spraying material within the storage section. Therefore, it can be suitably used in small spraying machines, which are prone to problems when supplying solids. A small spraying machine is, for example, a machine with a flow rate of compressed gas discharged from a nozzle of 1.5 to 2.5 m 3 Examples include those with a speed of 1 / minute.

[0029] The ceramic fibers may be selected depending on the application of the fibrous aggregate. The ceramic fibers are preferably one or more fibers selected from the group consisting of alumina fibers, mullite fibers, silica fibers, glass wool, and rock wool. The ceramic fibers preferably have a melting point of 500°C or higher. The upper limit of the melting point is not particularly limited, but is, for example, 1800°C or lower. The fibers may be either crystalline or amorphous. The fiber length is not particularly limited, but for example, fibers of 0.1 to 80 mm can be used. The fiber diameter is not particularly limited, but for example, fibers of 1 to 30 μm can be used.

[0030] The spray material binder is a powder containing one or more of a flocculant containing polyaluminum chloride and aluminum sulfate. The spray material binder may further contain carboxymethylcellulose or a carboxymethylcellulose derivative. The particle size distribution range of the spray material binder powder is not particularly limited, but can be, for example, 0.8 μm or more and 980 μm or less. Examples of the derivatives include sodium carboxymethylcellulose, potassium carboxymethylcellulose, lithium carboxymethylcellulose, and ammonium carboxymethylcellulose. Hereinafter, carboxymethylcellulose and its derivatives will be referred to as carboxymethylcellulose, etc.

[0031] The mass of aluminum sulfate relative to the mass of the raw material for the spraying compound is preferably, for example, 0.1 to 5.1 mass% in terms of anhydrous. The mass of aluminum sulfate relative to the mass of the raw material for the spraying compound can be 0.3 mass% or more. As aluminum sulfate, aluminum sulfate hydrate powder can be suitably used. The hydration number may change over time due to the absorption of water molecules in the environment. To convert the aluminum sulfate content to the amount equivalent to the anhydrous form, aluminum sulfate is heated at 460°C or higher to release water of crystallization, and then the mass is measured.

[0032] As the flocculant containing polyaluminum chloride, for example, a commercially available powder of flocculant for water treatment having an aluminum oxide (Al2O3) content of 30 mass% or more as determined according to JIS K 1475-1996 can be suitably used. The mass of the flocculant relative to the mass of the raw material for the spraying material is preferably, for example, 0.1 to 5.1 mass%. The mass of the flocculant relative to the mass of the raw material for the spraying material can be 0.3 mass% or more, or 1.8 mass% or more.

[0033] Although the detailed mechanism is unknown, it is speculated that aluminum sulfate or polyaluminum chloride aggregates the fine particles contained in the spray material, thereby preventing the spray material sprayed onto the target object from peeling off from the target object.

[0034] The binder for the spraying material preferably uses powdered carboxymethyl cellulose and / or a carboxymethyl cellulose derivative in combination with aluminum sulfate. This enhances the adhesion of the spraying material to the substrate. While the detailed mechanism is unclear, it is presumed to be based on the following mechanism: carboxyl groups, such as those in carboxymethyl cellulose, ionized by hydrogen, become negatively charged. The negatively charged carboxyl groups electrically attract aluminum ionized from aluminum sulfate, resulting in crosslinking and gelation of the spraying material, making it difficult for the spraying material to peel off from the substrate. Aluminum is a trivalent cation, and it is presumed that this gelation is more efficient than, for example, the crosslinking reaction between calcium, a divalent cation, and the negatively charged carboxyl groups of alginic acid ionized by hydrogen.

[0035] When carboxymethyl cellulose or the like is used in combination with aluminum sulfate, it is preferable that the carboxymethyl cellulose or the like contained in the raw material for the spraying material be 2 to 6 mass % and the aluminum sulfate be 1.5 to 3.5 mass % in anhydrous equivalent. It is even more preferable that the content of carboxymethyl cellulose or the like be 3 to 5 mass % and the content of aluminum sulfate be 2 to 3.2 mass % in anhydrous equivalent.

[0036] The formulation of the raw material for the spraying material containing the above-mentioned fibrous aggregate and powder of the binder for the spraying material is, for example, a powder containing multiple particles due to the granular fibrous aggregate and the binder for the spraying material.

[0037] The above-mentioned spraying material raw material can be used, for example, by mixing the spraying material raw material with a liquid component to prepare a spraying material, and then spraying the spraying material onto the object to be treated. Examples of the liquid component to be blended into the spraying material raw material include water, or water containing the secondary components to be contained in the spraying material. Examples of secondary components include refractory powders such as alumina powder and silica powder. Colloidal silica can also be used instead of silica powder. For example, the liquid component preferably contains 70% by mass or more, or 90% by mass or more of water. The liquid component preferably contains 100% by mass or less of water.

[0038] The particle size range of the raw material for the gunning material can be, for example, 7 mm or less. There is no particular lower limit to the particle size of the raw material for the gunning material, but it is, for example, 0.5 μm or more.

[0039] When the liquid is mixed with the fibrous aggregate for spraying material or the raw material for spraying material, for example, the liquid may be mixed in an amount of 0.6 to 2.0 times the mass of the solids. The amount of the liquid is more preferably 1.8 times or less, 1.5 times or less, or 1.3 times or less the mass of the solids.

[0040] Examples of the object to be treated include walking beams, walking beam posts, or furnace ceilings, walls, or floors that require insulation. Examples of furnaces include heating furnaces such as electric furnaces and gas furnaces. The spraying material may be sprayed onto the object to repair damaged areas, or may be used to construct new interior linings for walls, etc. The spraying material is suitable for use on structures that do not have a surface to support the spraying material in the vertical direction, such as ceilings, walls, and overhangs.

[0041] The raw material for the spraying material can be efficiently sprayed onto the object to be treated, for example, by using a spraying machine 5 as shown in Fig. 1. The spraying machine 5 in Fig. 1 includes a storage section 51, a pressurized gas supply section 52, a connection section 53 connecting the storage section 51 and the pressurized gas supply section 52, a flexible hose 54 connected downstream of the connection section, a rigid hollow tube 55 connected downstream of the flexible hose 54, and a liquid supply section 56.

[0042] Pressurized gas supply unit 52 supplies pressurized gas such as air to connection unit 53 or the like, and discharges the gas from a nozzle provided at the tip of hollow tube 55. Examples of pressurized gas supply unit 52 include a cylinder filled with pressurized gas, and an air compressor. The flow rate of the pressurized gas may be adjusted so that the solid content discharged from the nozzle is 2 to 20 kg / min, for example.

[0043] The storage section 51 is for storing a raw material for the spraying material 511 containing a fibrous aggregate and a binder for the spraying material. The storage section 51 may be, for example, a tank or a hopper.

[0044] The connection part 53 connects the pressurized gas supply part 52 and the storage part 51, and the pressurized gas and the raw material for the gunning material 511 are mixed inside the connection part. An example of the connection part is an ejector. The ejector uses the gas supplied from the pressurized gas supply part 52 as a driving source to suck in the raw material for the gunning material 511 stored in the storage part 51 and supply it to the flexible hose 54.

[0045] Hollow tube 55 is a hollow tube made of a rigid material such as metal, and is held by the operator as an operating rod when using spray machine 5. Compressed gas supplied from flexible hose 54 and raw material 511 for the spraying material are transported inside. When operating hollow tube 55 to change the direction of the nozzle at the tip of hollow tube 55, the flexible hose 54 elastically deforms, allowing for smooth operation. The nozzle functions as the discharge part for the spraying material.

[0046] The liquid supply section 56 supplies liquid to the raw material for the spraying material 511 that is transported by pressurized gas through the hollow pipe 55. In the example of Figure 1, the liquid supply section 56 is composed of a pipe connected to the hollow pipe 55 and a valve for changing the amount of liquid supplied.

[0047] From the nozzle provided at the tip of the hollow tube 55, the spray material 21, which is a mixture of liquid supplied from the liquid supply section 56 and raw material 511 for the spray material supplied from the storage section 51, is ejected together with a carrier gas.

[0048] In the above-mentioned spraying machine, the raw material for the spraying material and the liquid component are mixed in the conveying air inside the hollow tube to produce the spraying material, which is then sprayed onto the object to be treated from the tip of the tubular discharge part. [Example]

[0049] The present invention will be described in more detail below with reference to examples. The examples shown below are merely limited examples of embodiments of the present invention, and the technical scope of the present invention is not limited to the exemplified embodiments.

[0050] [Example 1] Granular fibrous aggregate was produced by the following method. First, a ceramic fiber blanket, which is an aggregate of short alumina fibers with an average fiber diameter of 6.1 μm, was placed in a crusher to crush the ceramic fibers. The crusher is equipped with a roller that rotates clockwise and a roller that rotates counterclockwise, and the raw material is placed between these rollers. The crusher used is equipped with a mesh with an opening of 5.0 mm, so that fibers smaller than 5.0 mm are discharged. The average fiber diameter was determined by randomly measuring the fiber diameter under a microscope (magnification 6000x).

[0051] A mixture of ceramic fibers discharged from the disintegrator and powder of carboxymethylcellulose sodium, a granulation binder, was rotated along the inner wall of a concrete mixer to granulate. The composition of ceramic fibers and granulation binder is shown in Table 1. The mixture was rotated along the inner wall of the concrete mixer at room temperature for 30 minutes to granulate. A small amount of water was added to the ceramic fibers during granulation. The granulated fibrous aggregate was dried at 110°C for 24 hours to obtain a granular fibrous aggregate. The fibrous aggregate was approximately spherical in shape. The obtained fibrous aggregate was sieved to obtain a fibrous aggregate with a particle size distribution range of 0.425 mm or more and less than 4.0 mm.

[0052] The fibrous aggregate obtained as described above and a powder of binder for spraying materials were mixed in the proportions shown in Table 2 to obtain a powdered raw material for spraying materials. In Example 1, a powder of sodium carboxymethylcellulose (purity 99.0% or higher) having a particle size of 1 to 106 μm and a powder of aluminum sulfate (17-hydrate) having a particle size of 1 to 850 μm were used as the binder for spraying materials. The amount of aluminum sulfate listed in Table 2 is the value converted into the mass of the anhydrous form. When converting to the anhydrous form, aluminum sulfate was heated at 500°C for 180 minutes to remove the water of hydration, and then the mass was measured.

[0053] [Example 2] A mixture of ceramic fibers similar to those used in Example 1 and powdered carboxymethyl cellulose, a granulation binder, was rotated along the inner wall of a concrete mixer to granulate. The mixture was rotated along the inner wall of the concrete mixer at room temperature for 30 minutes. When the ceramic fibers had granulated to a certain extent, silicone oil (dimethylpolysiloxane) with a purity of 100% (excluding unavoidable impurities) was added, and the mixture was then rolled in the concrete mixer for 10 minutes to granulate. The composition of each component is shown in Table 1. Approximately spherical granular fibrous aggregate was dried at 10°C for 24 hours and sieved to obtain a fibrous aggregate with a particle size distribution ranging from 0.425 mm to less than 4.0 mm. The silicone oil had a water contact angle of 101°, measured using the method described below.

[0054] The fibrous aggregate obtained as described above was mixed with a binder for a gunning material in the same manner as in Example 1 to obtain a powdered raw material for a gunning material.

[0055] [Examples 3 to 18] The spraying material raw materials for Examples 3 to 18 were obtained by the same method as Example 2, with the formulations changed as shown in Tables 1 to 4. The raw materials used were the same unless otherwise noted. In Example 12, polyaluminum chloride powder was used instead of aluminum sulfate. The polyaluminum chloride flocculant used was PAC250AD (registered trademark) from Taki Chemical Co., Ltd. The particle size of the polyaluminum chloride flocculant powder ranged from 1 μm to 850 μm. In Example 14, a rock wool ceramic blanket was used instead of alumina fiber as the ceramic fiber during granulation. The average fiber diameter of the rock wool, as confirmed using a microscope (magnification 6000x), was 6.1 μm. In Example 15, a commercially available fluororesin-based water repellent was used instead of silicone oil during granulation. The fluororesin-based water repellent was an emulsion of tetrafluoroethylene resin. The blending amounts in Table 1 correspond to the mass of the fluororesin excluding the solvent. The fluororesin-based water repellent had a water contact angle of 91°, measured using the method described below. In Example 16, powdered gum arabic (DSP GOKYO FOOD & CHEMICAL CO., LTD., product name: Gum Talha Powder) was used as the granulation binder instead of carboxymethyl cellulose. In Example 17, a mixture of Al2(SO4)3·14H2O (13% by mass) and Al2(SO4)3·8H2O (87% by mass) obtained by heating the aluminum sulfate (17-hydrate) of Example 1 at 80°C for 24 hours was used as the aluminum sulfate. The amount of aluminum sulfate listed in Table 4 is the value converted to the mass of the anhydrous form. The hydration number of the mixture was analyzed by powder X-ray diffraction. The 2θ measurement range for powder X-ray diffraction was 5 to 80°. In Example 18, aluminum sulfate (octahydrate) (commercially available reagent) was used as the aluminum sulfate. Powder X-ray diffraction analysis confirmed that the aluminum sulfate (octahydrate) was a pure substance, Al2(SO4)3·8H2O. The amount of aluminum sulfate listed in Table 4 is a value converted into the mass of the anhydrous form.

[0056] [Comparative Examples 1 to 3] The spray material materials for Comparative Examples 1 to 3 were obtained in the same manner as in Example 2, with the formulations changed as shown in Tables 1 and 4. In Comparative Example 2, powdered sodium alginate (pure substance) and powdered DL calcium lactate (pentahydrate) were used as the spray material binder. The amount of calcium lactate listed in Table 4 is the value converted to the mass of the anhydrous form. The particle size of sodium alginate ranged from 1 to 250 μm. The particle size of calcium lactate (pentahydrate) ranged from 1 to 500 μm. In Comparative Example 3, only powdered gelatin (pure substance) was used as the spray material binder. The particle size of gelatin ranged from 1 to 500 μm.

[0057] [Spray test] Using the spraying machine shown in Figure 1, a spraying test was conducted on a substrate using the powdered spraying material raw material of each Example or the powdered spraying material raw material of each Comparative Example. The powdered spraying material raw material of each Example or the powdered spraying material raw material of each Comparative Example was charged into the storage section of the spraying machine. Air was supplied from the pressurized gas supply section to transport the spraying material raw material stored in the storage section to the hollow tube. Inside the hollow tube, the transported spraying material raw material was mixed with water supplied from the liquid supply section. The mixed spraying material was sprayed onto the substrate from the discharge section of the spraying machine.

[0058] When spraying, the liquid to solids mixture ratio was optimized beforehand and then sprayed onto the target object. If the liquid content is low relative to the solids content, the sprayed material will not adhere well to the target object, resulting in dust generation and rebound. If the liquid content is high relative to the solids content, dust generation and rebound are less likely to occur, but the sprayed material will drip off the target object and will not build up properly. If the liquid to solids mixture ratio is appropriate, the above-mentioned rebound, dust generation, and dripping problems are less likely to occur. Tables 2 to 4 show the optimal amount of liquid to be added. The amount of water added was controlled by adjusting the water flow rate using a valve located in the sprayer's liquid supply section.

[0059] [Measurement of the optimal amount of liquid to be added] The hollow tube is equipped with a valve for adjusting the flow rate of the liquid. Before opening and closing the valve and conducting the spraying test, the flow rate (kg / min) of the liquid being supplied into the hollow tube was measured in advance using a flow sensor. The flow rate (kg / L) of the solids, i.e., the raw material for the spraying material, was determined by measuring the mass (kg) of the solids stored in the hopper in advance, and then measuring the time (min) required for the entire amount of solids to be discharged from the sprayer. The mass of the solids was divided by the time to determine the flow rate (kg / min) of the solids. The optimal amount of liquid to be added (times) relative to the solids was calculated from the flow rates of the liquid and solids using the following [Equation 1]. [Formula 1] Amount of liquid added (times) = Liquid flow rate (kg / min) ÷ Solid flow rate (kg / min)

[0060] [Adhesion evaluation] The adhesion of the sprayed material at the optimum amount of additive was evaluated for each Example and Comparative Example using the following method. The target object was a steel plate measuring 800 mm high and 800 mm wide, with Y-shaped anchors (YM5 from Namita Kiko Co., Ltd., wire diameter 8 mm, height 80 mm) arranged in a staggered pattern at 150 mm intervals. The target object was placed on the ceiling, and the sprayed material for each Example and Comparative Example was applied by directing the sprayer's discharge port from below to above the target object. The sprayed material was sprayed to a thickness of 100 mm, so that 20 mm of the target object covered the 80 mm thick Y-shaped anchors. The sprayed material was checked for falling and evaluated according to the following criteria. The results are shown in Tables 2 to 4. 〇: The sprayed material did not collapse even when sprayed to a thickness of 100 mm. ⊚: The sprayed material did not collapse even when the liquid amount was increased by 30% from the optimum amount described above. Figure 3 shows a photograph taken during the spraying test of Example 10. Figure 4 shows a photograph taken during the spraying test of Comparative Example 1, showing the state of the applied body falling.

[0061] [Setting test] In accordance with JIS A 1147-2019, a penetration resistance test using a penetration needle was conducted on test specimens made of the sprayed materials according to each Example or Comparative Example, and the initial and final setting times were determined. The test specimens were prepared by spraying the optimum amount of additive liquid into a circular container with a diameter of 120 mm and a depth of 100 mm to form a workpiece, smoothing the surface of the workpiece along the top surface of the container with a trowel to create a smooth surface, and then leaving it to harden. The cross-sectional area of ​​the penetration needle was 153.86 mm 2 The penetration value was 0.3N / mm 2 The time when the penetration value is 1.0 N / mm 2 The time when the test piece begins to lose fluidity is taken as the final setting time. The initial setting time indicates the time when the test piece begins to retain its shape, and the final setting time indicates the time when the test piece begins to retain its shape.

[0062] [Linear rate of change] The residual linear change rate was measured at 110°C in accordance with JIS R 2554-2005. The material was sprayed onto a 40mm x 40mm x 160mm formwork, dried at 110°C, and then removed from the formwork to prepare test specimens. The latent heat change rate (ΔLe) was calculated using the following formula. The length before drying was measured based on the length of the formwork. The total length of the formwork in the vertical direction was measured at several points using a length meter. To measure the length after drying at 110°C, immediately measure the entire length of the test piece in the longitudinal direction at several points after cooling it to room temperature. ΔLe = (L1 - L0) ÷ L0 × 100 where L0 is the average length (mm) of the formwork before drying, and L1 is the average length (mm) of the test piece after drying.

[0063] [Bulk density] The bulk density of the applied body was measured in accordance with JIS R 2655-2005, "Test method for bulk density of lightweight castable refractories (method using molded products)." Test specimens were prepared by spraying the material onto a 40mm x 40mm x 160mm formwork, drying at 110°C, and then removing the formwork.

[0064] [Thermal Conductivity] The thermal conductivity was measured in accordance with the "hot wire test" of JIS R 2616-2001. Samples dried at 110°C were used. [Contact angle evaluation] The contact angle of the water repellent agent used on the fibrous aggregate in the above Examples and Comparative Examples was measured in accordance with JIS R 3257:1999 "Test method for wettability of glass substrate surfaces." Test specimens were prepared by spraying each water repellent agent twice evenly onto a glass preparation from a distance of 20 cm, allowing it to dry, and then subjecting it to testing. The test was performed using the sessile drop method with 2 μl of distilled water (25°C).

[0065] The compressibility index, angle of repose, and tapped bulk density of the fibrous aggregate used in each example and comparative example were measured by the following methods. The results are shown in Table 1.

[0066] Compressibility Index For the fibrous aggregates used in each example and comparative example, the tapped bulk density and initial bulk density were measured using a tap density measuring instrument, Tap Denser (KYT-5000k), manufactured by Seishin Enterprise Co., Ltd., in accordance with the method of 7.1 of JIS R 1628-1997, and the compressibility index (%) was calculated using the formula [1]. The results are shown in Table 1 below. [Formula 1] Compressibility index (%) = [(tapped bulk density - initial bulk density) ÷ tapped bulk density] × 100

[0067] [Tap bulk density] The values ​​of the tapped bulk density used in the above formula 1 are shown in Table 1.

[0068] [Angle of repose] The angle of repose of the fibrous aggregate of each example and comparative example was determined using a tap density measuring instrument, Tap Denser (KYT-5000k), manufactured by Seishin Enterprise Co., Ltd. The conditions for measuring the angle of repose are as follows. The results are shown in Table 1 below. The measurement was performed by dropping the fibrous aggregate from a funnel until it overflowed around the measuring table, and the angle of the hypotenuse of the peak formed at that time was measured. Height of fibrous aggregate drop: 125mm from the bottom of the funnel to the base Diameter of measuring table: 80mm

[0069] [Table 1]

[0070] [Table 2]

[0071] [Table 3]

[0072] [Table 4]

[0073] As shown in Tables 2 to 4, when the spraying material of each Example was sprayed onto a structure that was not provided with a spraying material in the vertical direction, the spraying material did not peel off or fall off the target. On the other hand, when the spraying material of each Comparative Example was sprayed onto a structure that was not provided with a spraying material in the vertical direction, the spraying material peeled off and fell off the target due to its own weight.

[0074] As shown in Tables 2 to 4, the test pieces formed using the spray material raw materials of each Example tended to have a smaller linear change rate after heating than the spray material raw materials of each Comparative Example. Furthermore, the test pieces formed using the spray material raw materials of each Example had a low bulk density, a low thermal conductivity, and insulating performance.

[0075] It was confirmed that the spraying material raw materials of Examples 2 to 18, which contain fibrous aggregate treated with a water repellent, tend to have an even smaller optimum amount of additive liquid than the spraying material raw material of Example 1, which contains fibrous aggregate without a water repellent. It was also found that the spraying material raw materials of Examples 2, 10, 15, 16, 17, and 18 have improved adhesion to the substrate, and have the ability to firmly adhere to the substrate within a short time after spraying.

Claims

1. 80 to 99% by mass of granular fibrous aggregate; A spraying material raw material containing a powder of a spraying material binder, The binder powder for the spraying material is a raw material for the spraying material that contains one or more of a flocculant containing polyaluminum chloride and aluminum sulfate.

2. 2. The raw material for a gunning material according to claim 1, wherein the raw material for a gunning material contains 0.1 to 5.1 mass % of aluminum sulfate in terms of anhydride.

3. 3. The spraying material according to claim 1, wherein the spraying material contains 0.1 to 5.1 mass % of a flocculant containing polyaluminum chloride.

4. The spraying material according to claim 1 or 2, wherein the fibrous aggregate contains a water repellent.

5. The bulk density of the fibrous aggregate is 1.0 g / cm ３ The raw material for a spraying material according to claim 1 or 2, wherein:

6. The spraying material according to claim 1 or 2 is mixed with a liquid component in a conveying gas to prepare a spraying material, A spray material application method in which the spray material is sprayed onto the object to be applied from the tip of the discharge part together with a carrier gas.

7. 7. The method for applying a spraying material according to claim 6, wherein a liquid component is mixed in an amount of 0.6 to 1.8 times the mass of the raw material for the spraying material.

8. 8. The method for applying sprayed material according to claim 7, wherein the object is a structure that does not have a surface that supports the sprayed material in the vertical direction.

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