JP4757371B2 - Inorganic load-bearing face material and method for producing inorganic load-bearing face material - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an inorganic load bearing face material used as an alternative to a wood structure plywood widely used as a load bearing face material for a wooden house and the like, and a method for manufacturing the same.
[0002]
[Prior art]
In general, a house may receive a load from the side due to an earthquake or wind pressure, and it is necessary to design in consideration of such a load. For this reason, wood-structured plywood is widely used as a load-bearing surface material in wooden houses in order to increase strength.
On the other hand, as inorganic materials, fiber reinforced cement boards such as calcium silicate boards and wood fiber reinforced cement boards such as gypsum boards and wood wool cement boards have been used. Since the strength is insufficient, the performance that can be used as a substitute for structural plywood is not obtained.
[0003]
[Problems to be solved by the invention]
By the way, it is hard to say that the wood structure plywood is a combustible material and excellent in durability. In addition, environmental damage caused by deforestation and problems in the living environment due to adhesives have been pointed out.
On the other hand, fiber reinforced cement boards such as calcium silicate boards, ceramic boards such as gypsum boards and wood wool cement boards are insufficient in strength as load-bearing face materials, and the materials are brittle. It has the problem of poor nature and low nail retention.
[0004]
Accordingly, a first object of the present invention is to provide an inorganic load bearing material that is nonflammable, excellent in durability, has a high nail holding power, and can be used as a load bearing material with a small rate of change in length. .
The second object of the present invention is to provide a method for producing an inorganic load bearing material that is nonflammable, has excellent durability, has a high nail holding power, and has a low rate of change in length, and can be used as a load bearing material. That is.
[0005]
[Means for Solving the Problems]
In the invention of claim 1, the inorganic load-bearing face material is 20 to 60% by mass of cement, 5 to 50% by mass of a calcium silicate-based lightweight hydrothermal compound obtained by hydrothermal synthesis of a calcareous raw material and a siliceous raw material in advance, And a bulk specific gravity of 0.05 to 0.3 , a reinforcing fiber of 3 to 18% by mass , and a pulp fiber occupying 3 to 15% by mass of the reinforcing fiber and a filler of 0 to 60% by mass. Is obtained by wet molding and has a bulk specific gravity of 0.5 to 1.2, a bending strength of 10 to 30 N / mm ² and a wall magnification of 2.5 or more, thereby achieving the first object.
[0006]
In the invention according to claim 2, the inorganic load-bearing face material is 20 to 60% by mass of cement, 5 to 50% by mass of a calcium silicate-based lightweight hydrothermal compound obtained by hydrothermal synthesis of a calcareous raw material and a siliceous raw material in advance, And a bulk density of 0.05 to 0.3, a reinforcing fiber of 3 to 18% by mass , a pulp fiber occupying 3 to 15% by mass of the reinforcing fiber, and a filler of 0 to 60% by mass Obtained by wet-molding and laminating one or more kinds of green sheets in multiple layers, bulk specific gravity 0.5-1.2, bending strength 10-30 N / mm ² and wall magnification 2.5 or more. Thus, the first object is achieved.
[0007]
The invention according to claim 3 is characterized in that, in the invention according to claim 2, one or more net layers are included in the green sheet layer formed by laminating one or more kinds of green sheets.
[0008]
The invention according to claim 4 is the invention according to claim 1, claim 2 or claim 3, wherein the calcium silicate-based lightweight hydrothermal composition obtained by hydrothermal synthesis of a calcareous raw material and a siliceous raw material in advance has a bulk specific gravity. It is 0.05-0.3.
[0009]
In the invention of claim 5, in the invention of claim 1, claim 2, claim 3 or claim 4, as the reinforcing fiber, the pulp fiber is 3 to 15% by mass and the Young's modulus is 5 kN / mm ² or more. The fibers are characterized by comprising 0 to 2% by mass and fibers having a Young's modulus of less than 5 kN / mm ² consisting of 0 to 2% by mass.
[0010]
In the invention of claim 6, the inorganic load-bearing face material, cement 20 to 60% by mass, calcium silicate-based lightweight hydrothermal compound 5 to 50% by mass obtained by hydrothermal synthesis of a calcareous raw material and a siliceous raw material in advance, And a bulk density of 0.05 to 0.3, a reinforcing fiber of 3 to 18% by mass , a pulp fiber occupying 3 to 15% by mass of the reinforcing fiber, and a filler of 0 to 60% by mass The second object is achieved by curing a single-layer or multi-layer green sheet formed by wet-molding with a press pressure of 1 to ²⁰ N / mm ² and then curing.
[0011]
In the invention of claim 7, the inorganic load-bearing face material, cement 20 to 60% by mass, calcium silicate-based lightweight hydrothermal compound 5 to 50% by mass obtained by hydrothermal synthesis of a calcareous raw material and a siliceous raw material in advance, And a bulk density of 0.05 to 0.3, a reinforcing fiber of 3 to 18% by mass , a pulp fiber occupying 3 to 15% by mass of the reinforcing fiber, and a filler of 0 to 60% by mass The green sheet containing at least one net layer in a single layer or a plurality of layers formed by wet molding is molded by pressing with a press pressure of 1 to ²⁰ N / mm ² and then cured. Achieve the purpose of 2.
[0012]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, a preferred embodiment of the present invention will be described in detail with reference to FIGS.
FIG. 1 is a cross-sectional view of a single-layer inorganic load-bearing face material according to an embodiment of the present invention, and FIG. 2 is a cross-sectional view of a three-layer inorganic load-bearing face material.
FIG. 3 is a cross-sectional view of a three-layer inorganic load-bearing face material including two net layers.
These inorganic load-bearing face materials are composed of 20 to 60 % by mass of cement, calcium silicate light hydrothermal synthesis mainly composed of tobermorite and / or zonotlite based on hydrothermal synthesis of calcareous raw material and siliceous raw material in advance. objects 5 to 50 mass%, a green sheet obtained by wet molding the reinforcement fiber 3 to 18 weight percent and the formulation comprising a filler 0 to 60 wt%, be a single layer structure according to one formulation (FIG. 1) The green sheet is made into a multilayer structure by one kind of blending or two or more kinds of blending (FIG. 2), a structure in which one or more net layers 5 are provided in the single layer structure and the multilayer structure; By doing (FIG. 3), the bulk specific gravity is 0.5 to 1.2, the bending strength is 10 to 30 N / mm ^2, and the wall magnification is 2.5 or more with a small length change rate.
[0013]
The calcium silicate-based lightweight hydrothermal composition used in these inorganic load bearing materials uses a calcareous raw material and a siliceous raw material in advance, and the molar ratio of calcium oxide to silica is 0.55 to 1.10. A slurry having a concentration is hydrothermally synthesized at 150 to 230 ° C. using a stirring autoclave and has a bulk specific gravity of 0.05 to 0.3.
Silica materials include silica, diatomaceous earth, silica fume, and the like, and general-purpose materials such as quick lime are used as the calcareous materials. These calcium silicate-based lightweight hydrothermal compositions are tobermorite-based and / or zonotlite-based, and have a bulk specific gravity of 0.05 to 0.3 and a blending amount of 5 to 50%.
[0014]
Here, if the bulk specific gravity of the calcium silicate-based lightweight hydrothermal composition is less than 0.05, the required strength and the holding force of the nail cannot be obtained as the load bearing surface material, while if it exceeds 0.3, the load bearing surface It is difficult to reduce the weight of the material and ensure good nailing properties.
Further, if the amount of calcium silicate-based lightweight hydrothermal composition is less than 5 % by mass, it is difficult to reduce the weight of the load bearing member and to ensure good nailing properties, and the rate of change in length becomes large. On the other hand, when it exceeds 50 mass%, the required strength as a load bearing member and the holding power of the nail cannot be obtained.
[0015]
As the reinforcing fibers, pulp 3-15 wt% and a Young's modulus 5 kN / mm ² or more fibers 0-2 wt% and a Young's modulus 5 kN / mm ² less fibers are blended 0-2 wt%.
Pulp is necessary for improving the bending strength of the inorganic load-bearing face material, and is particularly effective for preventing cracking and cracking against nail driving and further improving the nail holding force. If the blending amount of the pulp is less than 3 % by mass, it is not sufficient for nailing workability. On the other hand, if it exceeds 15 % by mass , the rate of change in length becomes large and the durability is inferior.
[0016]
Further, as fibers other than pulp, in order to improve the bending strength and wall magnification as a load bearing face, fibers of 5 kN / mm ² or more having a Young's modulus higher than the bending Young's modulus of the matrix constituting the load bearing face. Blend. In addition, in order to improve impact resistance and prevent cracking and cracking due to nailing, and further improve performance against nail holding force, less than 5 kN / mm ² having a Young's modulus lower than the bending Young's modulus of the bearing face Blend fiber.
Here, the fibers having a Young's modulus of 5 kN / mm ² or more include organic fibers such as polyvinyl alcohol fibers, polynosic fibers, aramid fibers, hemp fibers, and inorganic fibers such as glass fibers and carbon fibers. On the other hand, examples of fibers having a Young's modulus of less than 5 kN / mm ² include organic fibers such as polypropylene fibers, polyester fibers, polyamide fibers, rayon fibers, and polyvinyl chloride fibers.
[0017]
The fiber length is 3 to 12 mm, preferably 3 to 6 mm. If the blending amount of fibers other than these pulps exceeds 3 % by mass, the fiber content becomes excessive and surface properties are inferior. Moreover, if the total amount of fibers including pulp exceeds 18 % by weight , nonflammability cannot be obtained.
[0018]
The present embodiment is characterized in that it is lightweight by using these constituent materials, has a high bending strength, has a small rate of change in length, and has a nailability and a nail holding force of a wall magnification of 2.5 or more. To achieve a load bearing face. Furthermore, wall magnification performance can be improved by making it multilayer.
As the multilayering, a 2-3 layer structure is preferable. The method of layering can be arbitrarily selected from the method of laminating in the green sheet state in the paper making process to the method of bonding each layer with an inorganic and / or organic binder after curing each layer as a single plate. it can.
The inorganic load-bearing face material blended with the calcium silicate-based lightweight hydrothermal composition has a bulk specific gravity of 0.5 to 1.2, and when it is formed into multiple layers, the bulk specific gravity of each layer can be implemented within this range. Moreover, the mixing | blending of each layer at the time of multilayering can select arbitrary mixing | blendings within the range of the mixing | blending of this invention by each required performance.
[0019]
As a method for producing this inorganic load-bearing face material, a green sheet is formed by a paper-making method using a mixture of cement, calcium silicate hydrothermal composition and reinforcing fiber as a slurry, and a press of 1 to ²⁰ N / mm ² After being pressure-molded with pressure, it is cured to obtain an inorganic load-bearing face material.
For this production, a general-purpose production method such as a continuous type paper making method such as a round net type paper machine, a long net type paper machine, a flow-on paper machine, or a batch type molding method such as a dehydrating press method is used. An inorganic load bearing face material having a single-layer or multi-layer structure can be obtained by one or a combination of these methods.
If the molding pressure is less than 1 N / mm ² , the required strength, nail holding force and surface smoothness cannot be obtained. On the other hand, if the molding pressure exceeds 20 N / mm ² , the weight cannot be reduced and nailability becomes difficult. As the curing of the inorganic load-bearing face material, there are natural curing, wet curing, steam curing and autoclave curing, but steam curing is preferable for shortening the curing time and processability such as nailing.
[0020]
As shown in FIG. 3, the net can be combined in a single layer or multiple layers and / or between layers as needed to improve performance. The composite of the net is effective for improving the performance of the inorganic load bearing member, particularly for improving the wall magnification. Moreover, it becomes possible to reduce the compounding quantity of a reinforcement fiber by combining a net | network.
4 to 6 are views showing a method for manufacturing an inorganic load-bearing face material including a net.
FIG. 4 is a diagram showing a manufacturing method of an inorganic load-bearing face material that forms a net layer using a flow-on papermaking apparatus, and FIG. 5 is a combination of a plurality of flow-on papermaking apparatuses and a round net-type papermaking apparatus. It is the figure which showed the inorganic yield strength face material manufacturing method containing the net | network 2 layer used, and FIG. 6 is the figure which showed the inorganic yield strength face material production method containing the net | network 2 layer which used two or more flow-on papermaking apparatuses in combination. It is.
[0021]
Here, as a method of inserting a net, there is a method of inserting when laminating in a green sheet state at the time of papermaking and in the papermaking process. In this case, in order to improve the adhesion between the net and the molding layer, an inorganic binder such as cement paste, water glass, silica fume, silica gel and alumina gel, acrylic emulsion, synthetic rubber latex such as SBR, and vinyl acetate emulsion It is effective to use organic binders such as these and binders in which these are combined.
Further, after curing each layer as a single plate, it is also possible to use inorganic and organic binders and bond each layer only by a plate material or sandwiching a net layer.
[0022]
As nets, polyvinyl alcohol fibers, polynosic fibers, aramid fibers, polypropylene fibers, polyester fibers, polyamide fibers, rayon fibers, polyvinyl chloride fibers, organic fibers such as hemp fibers, inorganic fibers such as glass fibers and carbon fibers, and metal fibers There is something that consists of etc. The net is inserted into the entire plate, and / or the net tape is inserted into the four circumferences and / or the middle part.
As a manufacturing method of the inorganic load-bearing face material in which the net shown in FIG. 3 is inserted , 20 to 60 % by mass of cement , 5 to 50 % by mass of calcium silicate-based lightweight hydrothermal composite prepared in advance, and 3 to 18 reinforcing fibers. A blend of 0 % to 60 % by mass and a filler is kneaded with water to form a slurry, which is wet-formed by a round netting machine, a long netting machine, a flow-on papermaking machine, a dehydration press molding machine, or the like. The obtained green sheet has a single layer structure by one kind of blending, the green sheet has a single layer structure or a multilayer structure by two or more kinds of blending, and the single layer structure and the multilayer structure have 1 A composite green sheet having a structure in which a net layer of at least one layer is provided is molded by pressing at a press pressure of 1 to 20 N / mm ² and then cured to obtain a plate material.
Further, after curing each layer as a single plate in the multilayer structure, each layer is joined with an inorganic and / or organic binder only with a plate material or with a net layer sandwiched between them, and crimped with a press pressure of 1 to 10 N / mm ^2. After that, it is cured and a board is obtained.
As shown in FIGS. 4 to 6, the pressure bonding is performed by applying pressure with a press machine 11 after being stacked by the adsorption stacking apparatus 10.
[0023]
Calcium silicate based lightweight hydrothermal synthesis comprises, using a pre-calcareous material and siliceous material, the molar ratio of calcium oxide to silica is a stirred autoclave with 5-15% concentration of the slurry is from 0.55 to 1.10 It is characterized by having a bulk specific gravity of 0.05 to 0.3, mainly composed of a tobermorite system and / or a zonotrite system obtained by hydrothermal synthesis at 150 to 230 ° C. As the siliceous raw material, general-purpose raw materials such as quartzite and calcareous raw material are used.
[0024]
Next, Examples 1 to 14 will be described with reference to the tables shown in FIGS.
Examples 1 to 14 were produced based on the raw material composition and production conditions shown in FIG. The raw material composition is shown in mass% as a whole.
In Example 1 and Examples 5 to 14, a 6-fold water was added to a mixture of each raw material mixture to form a slurry, and a single-layer green sheet obtained by a flow-on machine using this slurry was produced as shown in FIG. A single-layer plate having a thickness of about 10 mm was obtained by press molding at a press pressure of 5 to ²⁰ N / mm ² shown in the conditions. The plate was steam-cured and then naturally cured to obtain a specimen.
[0025]
Example 2, of the formulation shown in FIG. 7, a slurry by adding 10 volumes of water to the formulation which constitutes the front and back surface layers, a single layer obtained by round net type paper-making machine by using the slurry The green sheet was press-molded with a press pressure of 1 N / mm ² to obtain raw plates for a surface layer and a back layer having a thickness of 1.6 mm.
Further, among the formulations shown in FIG. 7, 6 times water is added to the formulation constituting the intermediate layer to form a slurry, and a 6 mm green sheet obtained by a flow-on machine using this slurry is used for the back layer. A laminate obtained by laminating on a green plate and further laminating a surface green plate thereon was press-molded with a press pressure of 10 N / mm ² to obtain a green laminate having a total thickness of 8 mm. The raw plate was steam-cured and then naturally cured and cured to obtain a specimen.
[0026]
In Example 3, a raw plate for a surface layer and a back layer having a thickness of 1.7 mm and a green plate for an intermediate layer having a thickness of 7 mm were obtained in the same manner as in Example 2. When laminating this, a vinylon net having an opening of 5 × 5 mm was sandwiched between the back layer and the intermediate layer and between the intermediate layer and the surface layer, and was press-molded with a press pressure of 10 N / mm ² , and the total thickness was 9 mm. A raw laminate was obtained. The raw plate was steam-cured and then naturally cured and cured to obtain a specimen.
[0027]
Example 4, of the formulation shown in FIG. 7, a slurry by adding 10 volumes of water to the formulation which constitutes the front and back surface layers, a single layer obtained by round net type paper-making machine by using the slurry The green sheet was pressure-molded with a press pressure of 10 N / mm ² , and after curing with steam, was naturally cured and cured to obtain cured plates for the surface layer and the back layer having a thickness of 1.5 mm. Further, among the blends shown in FIG. 7, a 6 mm green sheet obtained by a flow-on machine using a slurry obtained by adding 6 times water to the blend constituting the intermediate layer is pressed with 6 N / mm ² . It was pressure-molded with pressure, cured naturally after steam curing, and a 6 mm cured plate was obtained.
Next, a binder prepared by mixing 10% of SBR latex with cement paste is applied on the cured plate for the back layer, and an alkali-resistant glass fiber net having an opening of 5 × 5 mm is laminated thereon, and an intermediate layer cured plate is laminated. Furthermore, a binder in which 10% of SBR latex is mixed with cement paste is applied thereon, an alkali-resistant glass fiber net having an opening of 5 × 5 mm is stacked, a surface-hardened plate is laminated, and pressed with a press pressure of 3 N / mm ^2. Molded to obtain a green laminate having a total thickness of 10 mm. This laminate was steam cured and then naturally cured and cured to give a specimen.
These plates were dried and tested. The results are shown in the table of FIG.
[0028]
Comparative Examples 1-8 were manufactured based on the raw material composition and manufacturing conditions shown in FIG. A water layer of 6 times is added to the mixture of each raw material to form a slurry, and a single-layer green sheet obtained using a flow-on paper machine using this slurry is pressed at 10 to 25 N / mm ² shown in the production conditions of FIG. A single layer plate having a thickness of about 10 mm was obtained by pressure molding. This plate was steam-cured and then naturally cured and cured to give a specimen.
The calcium silicate-based lightweight hydrothermal composite used in the zonotlite system had a bulk specific gravity of 0.15, but only Comparative Example 5 used a hydrothermal composite with a bulk specific gravity of 0.40 that was insufficient in hydrothermal synthesis. .
In Comparative Example 9, a commercially available asbestos-free calcium silicate plate having a bulk specific gravity of 0.8 and a thickness of 8 mm was used.
In Comparative Example 10, a commercially available structural plywood having a thickness of 9 mm was used.
These plates were dried and tested as in the examples. The results are shown in the table of FIG.
[0029]
As shown in the tables of FIG. 9 and FIG. 10, the example is lighter in weight and superior in bending strength than the comparative example, is excellent in nailing performance and nail holding force, and has a large wall magnification despite its light weight. Improvements are being made. In Comparative Example 4, the non-flammability cannot be obtained because the amount of fibers is too large, and the bending strength is almost similar to that in Comparative Example 10, and the rate of change in length is greatly reduced and the wall magnification is also equal. The above performance was obtained. Regarding the incombustibility, all the examples were more than the semi-incombustible material with respect to the combustible material of Comparative Example 10. Further, Comparative Example 6 using pearlite as a lightweight material other than the calcium silicate-based lightweight hydrothermal composition has a low specific gravity but a low bending strength and a high rate of change in length.
As described above, it can be said that each example has significantly improved quality as compared with the conventional inorganic board and has sufficiently excellent performance as a substitute for the structural plywood.
[0030]
7 and 9, the calcium silicate-based lightweight hydrothermal composition is made from powdered silica and quicklime, and has a calcium oxide / silica molar ratio of 0.83 and a stirring autoclave at a slurry concentration of 10%. Was hydrothermally synthesized. The tobermorite system was hydrothermally synthesized at 180 ° C. for 3 hours and a bulk specific gravity of 0.13 was used. The zonotlite system was hydrothermally synthesized at 195 ° C. for 4 hours and used with a bulk specific gravity of 0.15.
The hydrothermal compound used in Comparative Example 5 was hydrothermally synthesized at 140 ° C. for 5 hours, and a bulk specific gravity of 0.40 was used.
The specific gravity test was measured according to JIS A 5430.
The bending test was measured according to JIS A 5430.
The rate of change in length was measured according to JIS A 5430.
Nailability: When the wall magnification test specimen was prepared, the test plate was visually observed for cracks and cracks, and the nailability was evaluated. Good with no abnormalities were indicated by ○, slightly abnormal by Δ, and abnormal by ×.
The nail holding force was evaluated by observing the nailing portion of the specimen after the wall magnification test with the naked eye, and observing the expansion, cracking, and cracking of the nail hole. Good with no abnormalities were indicated by ○, slightly abnormal by Δ, and abnormal by ×.
Wall magnification was carried out in accordance with the Japanese style of the Japan Architecture Center “Technical Rules for Assessment of Structural Strength of Low-Rise Buildings (Wooden)”.
The fire-proof material test was performed according to the method prescribed in Ministry of Construction Notification No. 1828 for non-combustible materials. Moreover, the semi-incombustible material and the flame retardant material were carried out in accordance with the method prescribed in Ministry of Construction Notification No. 1231 in 1976.
[0031]
【The invention's effect】
In invention of Claim 1-5, it is excellent in light weight, nonflammability, dimensional stability, wall magnification, and nailing property, and obtains the inorganic strength bearing surface material which has high strength as a lightweight inorganic material. Can be used as an alternative to structural plywood.
In particular, in the invention described in claim 3, by providing the net layer, it is possible to obtain a higher strength inorganic bearing material.
[0032]
In the inventions according to claims 6 and 7, an inorganic load-bearing face material that can be used as a load-bearing face material that is nonflammable, has excellent durability, has a high nail holding force, and has a small rate of change in length can be manufactured. .
[Brief description of the drawings]
FIG. 1 is a cross-sectional view of a single-layer inorganic load-bearing face material.
FIG. 2 is a cross-sectional view of a three-layer inorganic load-bearing face material.
FIG. 3 is a cross-sectional view of a three-layer inorganic load-bearing face material including two net layers.
FIG. 4 is a view showing a method for producing an inorganic load-bearing face material including a net layer using a flow-on papermaking apparatus.
FIG. 5 is a view showing a method for producing an inorganic load-bearing face material including two layers of nets using a combination of a plurality of flow-on paper making devices and a round net paper making device.
FIG. 6 is a diagram showing a method for producing an inorganic load-bearing face material including two net layers using a combination of a plurality of flow-on papermaking apparatuses.
FIG. 7 is a table showing examples of the present invention.
FIG. 8 is a table showing examples of the present invention.
FIG. 9 is a table showing a comparative example of the present invention.
FIG. 10 is a table showing a comparative example of the present invention.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Single layer board 2 Surface layer 3 Middle layer 4 Back layer 5 Net 6 Raw material slurry 7 Suction box 8 Felt 9 Roll press 10 Adsorption laminating device 11 Press machine 12 Making roll 13 Slurry bat 14 Wire cylinder

Claims (7)

Cement 20-60 mass%, calcium silicate light hydrothermal composition 5-50 mass% obtained by hydrothermal synthesis of calcareous raw material and siliceous raw material in advance, bulk specific gravity 0.05-0.3 , reinforcing fiber 3 It is obtained by wet-molding a composition comprising pulp fibers occupying 3 to 15% by mass, and fillers 0 to 60% by mass , and having a bulk specific gravity of 0.5 to An inorganic load bearing surface material having a bending strength of 10 to 30 N / mm ² and a wall magnification of 2.5 or more. Cement 20-60 mass%, calcium silicate-based lightweight hydrothermal composition obtained by hydrothermal synthesis of calcareous raw material and siliceous raw material in advance 5-50 mass%, bulk specific gravity 0.05-0.3, reinforcing fiber 3 It is obtained by wet-molding a composition comprising 1 to 18% by mass , and pulp fibers occupying 3 to 15% by mass of the reinforcing fibers, and 0 to 60% by mass of fillers. An inorganic load-bearing face material comprising a plurality of green sheets laminated and having a bulk specific gravity of 0.5 to 1.2, a bending strength of 10 to 30 N / mm ² and a wall magnification of 2.5 or more.   The inorganic load-bearing face material according to claim 2, wherein the green sheet layer formed by laminating a plurality of one or more kinds of green sheets includes at least one net layer.   The calcium silicate-based lightweight hydrothermal composition obtained by hydrothermally synthesizing a calcareous raw material and a siliceous raw material in advance has a bulk specific gravity of 0.05 to 0.3. 3. An inorganic bearing surface material according to 3. The reinforcing fiber is composed of 3 to 15% by mass of pulp fiber , 0 to 2% by mass of fiber having a Young's modulus of 5 kN / mm ² or more, and 0 to 2% by mass of fiber having a Young's modulus of less than 5 kN / mm ^2. The inorganic load-bearing face material according to claim 1, claim 2, claim 3 or claim 4. Cement 20-60 mass%, calcium silicate-based lightweight hydrothermal composition obtained by hydrothermal synthesis of calcareous raw material and siliceous raw material in advance 5-50 mass%, bulk specific gravity 0.05-0.3, reinforcing fiber 3 A single-layer or multi-layer green sheet that is formed by wet-molding a composition comprising 1 to 18% by mass of pulp fiber, 3 to 15% by mass of the reinforcing fibers, and 0 to 60% by mass of a filler. A method for producing an inorganic load-bearing face material, which is obtained by pressure-molding with a press pressure of 1 to ²⁰ N / mm ² and then curing. Cement 20-60 mass%, calcium silicate-based lightweight hydrothermal composition obtained by hydrothermal synthesis of calcareous raw material and siliceous raw material in advance 5-50 mass%, bulk specific gravity 0.05-0.3, reinforcing fiber 3 A single layer or multiple layers formed by wet-molding a composition consisting of 3 to 15% by mass of pulp fiber and 0 to 60% by mass of a filler. A method for producing an inorganic load bearing material, comprising: forming a green sheet including one or more net layers by pressing with a press pressure of 1 to ²⁰ N / mm ² and then curing.

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