Porous forming plate

Abstract

This invention relates to a molded plate, which is a porous molded plate comprising 35-70% by mass of a substance that does not participate in the pozzolanic reaction, 20-61.5% by mass of cement, 1-3% by mass of synthetic fiber, and 2.5-7% by mass of pulp, wherein in the pore size distribution of the molded plate obtained by mercury intrusion porosimetry, the ratio (B) / (A) of the pore volume (B) in the range of 6-560 nm to the pore volume (A) in the range of 660-9100 nm is 1.70-6.0.

Description

Porous forming plate This patent application claims priority under the Paris Convention with respect to Japanese Patent Application No. 2021-179694 (filed on November 2, 2021), the entirety of which is incorporated herein by reference. The present invention relates to a porous shaped plate. Cement-based sheet metal is produced by forming a slurry through a screen, suspending cement and fibers in an aqueous medium, and then curing the resulting sheet. Due to its versatility, this method is widely used, particularly in the construction industry, for manufacturing ceiling, interior, exterior, and flooring materials. However, cement production requires a significant amount of energy, resulting in substantial carbon dioxide emissions. Furthermore, the use of autoclaves for curing during manufacturing, typically employing steam boilers, also emits carbon dioxide. Therefore, to reduce carbon dioxide emissions, a cement-based sheet metal that eliminates the need for autoclave curing and reduces the proportion of cement has been proposed. For example, Patent Document 1 discloses a board material comprising a hydraulic binder such as cement, a filler such as calcium carbonate, and synthetic fibers; Patent Document 2 discloses an inorganic board material comprising a matrix-forming hydrated raw material, an inorganic filler, reinforcing fibers, and a calcium silicate hydrate; and Patent Document 3 discloses an energy-saving and environmentally friendly lightweight partition wall, which is manufactured from raw materials containing Portland cement, calcium carbonate, calcium oxide, paraffin diatomaceous earth composite phase change material, modified carbon fiber, activated bentonite, rubber powder, modified loess powder, solid industrial waste, fibers, initial strength enhancer, water-reducing agent, foaming agent, rare earth catalyst, and water in a specific ratio. [Prior Art Documents] [Patent Documents] [Patent Document 1] U.S. Patent Application Publication No. 2005 / 72056 [Patent Document 2] Japanese Patent Application Publication No. 2005-205879 [Patent Document 3] Chinese Patent Application Publication No. 108276023 [The problem the invention aims to solve] However, there has been a continuous need to develop formed sheets that reduce carbon dioxide emissions while also possessing superior performance, such as high flexural strength and low dimensional change rate. Therefore, the problem this invention aims to solve is to provide a formed sheet with high flexural strength and low dimensional change rate. [Means for solving the problem] In order to solve the aforementioned problems, the inventors of this case have repeatedly and thoroughly studied the molded plate and completed the present invention. That is, the present invention includes the following suitable embodiments. [1] A molded plate, which is a porous molded plate comprising 35 to 70% by mass of a substance that does not participate in the pozzolanic reaction, 20 to 61.5% by mass of cement, 1 to 3% by mass of synthetic fiber, and 2.5 to 7% by mass of pulp, wherein in the pore size distribution of the molded plate obtained by mercury intrusion porosimetry, the ratio (B) / (A) of the pore volume in the range of 6 to 560 nm to the pore volume in the range of 660 to 9100 nm is 1.70 to 6.0. [2] The molded plate described above [1], wherein the substance that does not participate in the pozzolanic reaction is selected from one or more substances including calcium carbonate, silica powder and talc. [3] The molded plate described above [2], wherein the calcium carbonate is heavy calcium carbonate. [4] The forming plate described in any one of [1] to [3] above further comprises one or more substances selected from the group consisting of mica, fly ash and silica ash. [5] The forming plate described in any one of [1] to [4] above, wherein the total content of synthetic fibers and pulp is 7% by mass or less relative to the total mass of the forming plate. [6] The average fiber diameter of the synthetic fibers is 50 μm or less. The forming plate described in any one of [1] to [5] above, wherein... [7] The forming plate described in [6] above, wherein the average fiber diameter of the synthetic fibers is 5 μm or more and 40 μm or less. [8] The forming plate described in any one of [1] to [7] above, wherein the aspect ratio of the synthetic fibers is 150 or more and 1000 or less. [9] The forming plate described in any one of [1] to [8] above, wherein the synthetic fibers are selected from at least one of the group consisting of polyvinyl alcohol fibers, polyethylene fibers, polypropylene fibers, acrylic fibers, polyaramid fibers and nylon fibers.

[10] The molded sheet described in any of [1] to [9] above, wherein the water absorption rate, as determined according to JIS A 5430:2018, is 15% or more and 28% or less.

[11] The molded sheet described in any of [1] to

[10] above, wherein the total calorific value, as determined according to the exothermic test in JIS A 5430:2018, is 8.0 MJ / m³. 2 The following.

[12] The molded plate described in any of [1] to

[11] above, wherein the bulk density measured according to JIS A 5430:2018 is 1.50 g / cm³. 3 The above.

[13] The molded sheet described in any of [1] to

[12] above, wherein the flexural strength upon water absorption, as measured in accordance with JIS A 1408:2017, is 15 N / mm. 2

[14] The molded plate described in any of [1] to

[13] above, wherein the water absorption rate measured according to JIS A 5430:2018 is 26% or less.

[15] The molded plate described in any of [1] to

[14] above, wherein the aforementioned pore volume (B) is 2.50 mL / g or less. [Effects of the Invention] According to the present invention, a shaped plate having high bending strength and low dimensional change rate can be provided. [The form in which the invention is carried out] Hereinafter, embodiments of the present invention will be described in detail. However, the scope of the present invention is not limited to the embodiments described herein, and various modifications may be made without departing from the spirit of the invention. The molding plate of the present invention comprises, relative to its total mass, 35-70% by mass of a substance that does not participate in the pozzolanic reaction, 20-61.5% by mass of cement, 1-3% by mass of synthetic fiber, and 2.5-7% by mass of pulp. If the proportions of the components deviate from the above-mentioned specific range, it is difficult to obtain a molding plate that combines high flexural strength and low dimensional change rate. Preferably, relative to the total mass of the molding plate, the molding plate comprises 40-67.5% by mass of a substance that does not participate in the pozzolanic reaction, 25-60.5% by mass of cement, 1-2% by mass of synthetic fiber, and 2.5-6% by mass of pulp; more preferably, it comprises 45-65% by mass of a substance that does not participate in the pozzolanic reaction, 30-59.5% by mass of cement, 1-1.5% by mass of synthetic fiber, and 3-5% by mass of pulp. In a preferred embodiment, the total content of synthetic fibers and pulp relative to the total mass of the formed sheet is 7% by mass or less, preferably 6% by mass or less. If the total content of synthetic fibers and pulp is below the aforementioned upper limit, the total heat generation of the formed sheet is more likely to be lower, which means that the formed sheet has excellent flame retardancy. The molded plate of the present invention is porous. In the pore size distribution of the molded plate obtained by mercury intrusion porosimetry, the ratio (B) / (A) of the pore volume (B) in the range of 6 to 560 nm to the pore volume (A) in the range of 660 to 9100 nm is 1.70 to 6.0, preferably 1.75 to 5.8, more preferably 1.80 to 5.6, and particularly preferably 1.85 to 5.4. A ratio (B) / (A) of 5.3 or less, more preferably 5.1 or less, and even more preferably less than 5.0, results in higher flexural strength and lower dimensional change rate, and facilitates higher yield in the manufacturing of the molded plate. Furthermore, a ratio (B) / (A) of 4.9 or less, 4.8 or less, 4.5 or less, and 4.0 or less are also possible. Furthermore, the ratio (B) / (A) is preferably 2.00 or higher, more preferably 2.10 or higher, further preferably 2.20 or higher, and even more preferably 2.50 or higher. The ratio (B) / (A) can be adjusted to a desired value by, for example, using a material with a specific Blaine surface area as a non-volcanic ash reaction material, and / or by adjusting the molding conditions (especially the pressing pressure). The pore volume ratio (B) / (A) can be determined by the method described in the examples. The inventors of this case unexpectedly discovered that by including the aforementioned four components (a substance that does not participate in the pozzolanic reaction, cement, synthetic fibers, and pulp) in a specific ratio (B) / (A) of the molded sheet, it is possible to achieve both high flexural strength and low dimensional change rate in the molded sheet. The reason for this is not yet clear, but the following mechanism is presumed. The molded sheet of the present invention can be manufactured by hardening a hardening composition containing the aforementioned four components. By applying appropriate pressure during the hardening process, the substance that does not participate in the pozzolanic reaction moderately fills the voids in the molded sheet during hardening, resulting in improved adhesion between the synthetic fibers and the cement matrix. Furthermore, the substance that does not participate in the pozzolanic reaction does not cause defects such as cracks or warping that may occur as the pozzolanic reaction proceeds. Therefore, it is presumed that the molded body exhibits high flexural strength and low dimensional change rate. However, the above is a speculation, and the present invention is not limited to this mechanism. The pore volume (B) in the range of 6–560 nm is preferably 2.50 mL / g or less, more preferably 2.40 mL / g or less, particularly preferably 2.30 mL / g or less, and even more preferably 2.20 mL / g or less. If the pore volume (B) is below the aforementioned upper limit, the resulting molded sheet tends to have excellent flexural strength when dry and when absorbing water. As mentioned above, the pore volume (B) being below the aforementioned upper limit is related to the high adhesion between the synthetic fiber and the cement matrix, and it is speculated that the molded sheet tends to have excellent flexural strength when dry and when absorbing water. Furthermore, since pores in the range of 6–560 nm have a significant impact on water absorption, it is speculated that by keeping the pore volume (B) below the aforementioned upper limit, the influence of water is reduced, particularly tending to increase the flexural strength when absorbing water. Also, when the pore volume (B) is preferably 2.10 mL / g or less, more preferably 2.00 mL / g or less, it is easier to obtain a higher yield when manufacturing the molded sheet. The pore volume (B) can be adjusted to a desired value, for example, by using a material with a specific Blaine surface area as a non-reactive material in the pozzolanic reaction, and / or by adjusting the molding conditions (especially the pressing pressure). The pore volume (B) can be determined by the methods described in the examples. <Substances that do not participate in the volcanic ash reaction> The substances that do not participate in the volcanic ash reaction are preferably selected from one or more substances in the group consisting of calcium carbonate, silica powder, and talc. From the viewpoint of availability and cost, heavy calcium carbonate is preferred as the substance that does not participate in the volcanic ash reaction. Materials that do not participate in volcanic ash reactions are preferably those with a density of 2200–12000 cm⁻¹ 2 / g, preferably 3000~11000cm 2 / g, with an optimal value of 4000~11000cm 2 / g of Blaine specific surface area. If the Blaine specific surface area is within the aforementioned range, a specific ratio (B) / (A) is easily obtained in the forming plate. In the case of using two or more substances that do not participate in the pozzolanic reaction with different Blaine specific surface areas, the Blaine specific surface area in their ratio is preferably within the aforementioned range. For example, when using Blaine specific surface area of ​​2500 cm² at a mass ratio of 50:50. 2 The specific surface area of ​​substance 1 that does not participate in the volcanic ash reaction is 6500 cm². 2 When substance 2, which does not participate in the volcanic ash reaction, is present in g, the Braun specific surface area, calculated based on the ratio of substances 1 and 2, is 4500 cm². 2 / g (=2500×0.5+6500×0.5). Furthermore, the optimal Blaine surface area for substances that do not participate in volcanic ash reactions is 10000 cm². 2 Below / g, preferably 9000cm 2 When the ratio is below a certain value, higher yields are easily obtained when manufacturing the molded plates. The Bryan specific surface area can be determined using the air permeation method according to JIS R5201:2015. These substances that do not participate in volcanic ash reactions are available on the market. As an example of commercially available products, calcium carbonate (grade 1) manufactured by Sankyo Flour Co., Ltd. can be cited. <Cement> Examples of cement used in this invention include Portland cement such as ordinary Portland cement, early-strength Portland cement, ultra-early-strength Portland cement, and medium-heat Portland cement; alumina cement; blast furnace cement; silica cement; fly ash cement; and white Portland cement. These cements can be used alone or in combination of two or more types. From the viewpoint of versatility and / or cost, ordinary Portland cement is preferred. From the viewpoint of easily achieving early strength development, early-strength Portland cement or ultra-early-strength Portland cement is preferred. From the viewpoint of easily achieving improved long-term strength, blast furnace cement is preferred. As mentioned above, cement is available on the market. For example, ordinary Portland cement manufactured by Pacific Cement Corporation can be cited as a commercially available product. <Synthetic Fibers> The average fiber diameter of the synthetic fiber is preferably 5 μm or more, more preferably 6 μm or more, particularly preferably 7 μm or more, preferably 50 μm or less, more preferably 40 μm or less, and particularly preferably 30 μm or less. If the average fiber diameter of the synthetic fiber is above the aforementioned lower limit and below the aforementioned upper limit, it is easy to combine good dispersibility of the synthetic fiber in the curing composition with good fiber reinforcement in the molded article. The average fiber diameter is obtained by randomly selecting 100 fibers, measuring the fiber diameter at the center of the longitudinal direction of each fiber using an optical microscope, and calculating the average value. The average fiber length of the synthetic fiber is preferably 2–30 mm, and more preferably 2–20 mm, from the viewpoint of easily achieving both good fiber dispersion in the curing composition and good fiber reinforcement in the molded body. The average fiber length can be obtained according to JIS L 1015:2010. The aspect ratio (fiber length / fiber diameter) of synthetic fibers is preferably 150 or higher, more preferably 175 or higher, particularly preferably 200 or higher, preferably 1000 or lower, more preferably 900 or lower, and particularly preferably 800 or lower. If the aspect ratio of the synthetic fibers is above the aforementioned lower limit and below the aforementioned upper limit, it is easy to achieve both good dispersibility of synthetic fibers in curable compositions and good fiber reinforcement in molded articles. The aspect ratio can be calculated from the average fiber length and the average fiber diameter. The tensile strength of the synthetic fiber is preferably 3 cN / dtex or higher, more preferably 5 cN / dtex or higher, and especially preferably 7 cN / dtex or higher. If the tensile strength of the synthetic fiber is above the aforementioned lower limit, it is easier to improve the fiber reinforcement in the formed plate. In this invention, the upper limit of the tensile strength of the synthetic fiber is appropriately set according to the type of fiber, for example, 30 cN / dtex or lower. The tensile strength of the fiber can be obtained according to JIS L 1015:2010. Synthetic fibers can be inorganic or organic. Organic synthetic fibers are preferred, and more preferably selected from at least one group including polyvinyl alcohol (hereinafter sometimes referred to as "PVA") fibers, polyethylene fibers, polypropylene fibers, acrylic fibers, polyaramid fibers, and nylon fibers. From the viewpoint of easily imparting superior reinforcement to the molded sheet and being inexpensive, PVA-based fibers and / or polypropylene fibers are preferred. When using PVA-based fibers, such as vinylon fibers, as synthetic fibers, PVA-based fibers with the following characteristics can be used. The degree of polymerization of the PVA-based polymer constituting the PVA-based fiber can be appropriately selected according to the purpose and is not particularly limited. Considering the mechanical properties of the resulting fiber, the average degree of polymerization of the PVA-based polymer, obtained from the viscosity of the aqueous solution at 30°C, is preferably about 500 to 20,000, more preferably about 800 to 15,000, and particularly preferably about 1,000 to 10,000. From the viewpoint of the strength of the resulting fiber, the average degree of polymerization of the PVA-based polymer is preferably 1,000 or more, more preferably 1,200 or more, more preferably 1,500 or more, and particularly preferably 1,750 or more. The PVA-based polymer can be a medium degree of polymerization product with an average degree of polymerization of 1,000 or more but less than 3,000, or a high degree of polymerization product with an average degree of polymerization of 3,000 or more. The degree of saponification of PVA-based polymers can be appropriately selected according to the purpose and is not particularly limited. From the viewpoint of the mechanical properties of the resulting fibers, the degree of saponification of PVA-based polymers can be, for example, 95 mol% or more, preferably 98 mol% or more. The degree of saponification of PVA-based polymers can be 99 mol% or more, or 99.8 mol% or more. If the degree of saponification of PVA-based polymers is above the aforementioned lower limit, then the resulting fibers are more likely to have good mechanical properties, processability, and manufacturing cost. The PVA-based fibers used in this invention can be manufactured by dissolving the PVA polymer in a solvent and spinning and thermally extending it using any of the following methods: wet spinning, wet-dry spinning, or dry spinning. Wet spinning involves ejecting the spinning solution from the spinning nozzle into a direct coagulation bath. Wet-dry spinning involves temporarily ejecting the spinning solution from the spinning nozzle into air or an inert gas at an arbitrary distance, and then introducing it into the coagulation bath. Dry spinning involves ejecting the spinning solution into air or an inert gas. The PVA-based fibers can be extended as needed after spinning. Furthermore, acetalization, a common treatment in PVA-based fibers, can also be performed. The solvent used in the spinning solution for PVA-based fibers is not particularly limited, as long as it can dissolve PVA. For example, one or more of the following can be used: water, dimethyl methacrylate (DMSO), dimethylformamide, dimethyl acetamide, and polyols (e.g., glycerol, ethylene glycol, and triethylene glycol). In this invention, when wet spinning is performed, water or an organic solvent is preferred. Water and DMSO are particularly preferred from the viewpoint of ease of supply and environmental impact. The polymer concentration in the spinning solution varies depending on the composition and degree of polymerization of the PVA-based polymer and the type of solvent, but is generally 6–60% by mass. The solvents mentioned above can also be used in dry spinning. In that case, water or organic solvents can be used. Without impairing the effects of the present invention, the spinning solution may contain additives in addition to PVA-based polymers, depending on the purpose. Examples of additives include boric acid, surfactants, antioxidants, decomposition inhibitors, antifreeze agents, pH adjusters, masking agents, colorants, and oils. The solvent used in the coagulation bath can be appropriately selected based on the type of solvent used in the spinning solution. When the spinning solution is an aqueous solution, an aqueous solution of an inorganic salt (e.g., sodium sulfate, ammonium sulfate, sodium carbonate, or sodium hydroxide) or an alkaline aqueous solution that has coagulation ability against PVA-based polymers can be used as the coagulation bath. When the spinning solution is an organic solvent solution, an organic solvent that has coagulation ability against PVA-based polymers can be used as the coagulation bath, such as alcohols like methanol, ethanol, propanol, or butanol, or ketones like acetone, methyl ethyl ketone, or methyl isobutyl ketone. In this invention, from the viewpoint of fiber tensile strength, it is preferable to use PVA-based fibers obtained by dry spinning or PVA-based fibers obtained by wet spinning from a spinning solution using water or an organic solvent as a solvent. To remove the solvent from the solidified yarn by extracting it from the spinning solution, the yarn can be passed through an extraction bath, or wet stretching can be performed simultaneously during extraction. After wet stretching, the fibers are dried, and further dry heat stretching can be performed as needed. When stretching is performed, the total stretch ratio (the product of the wet stretching and the stretch ratio after drying) can be, for example, 5 to 25 times, preferably about 8 to 20 times. As synthetic fibers, commercially available fibers can be used. Examples include organic fibers such as polyvinyl alcohol fibers manufactured by Kuraray Co., Ltd., polypropylene fibers manufactured by Yamato Spinning Co., Ltd., and nylon fibers manufactured by Toray Co., Ltd., as well as inorganic fibers such as glass fibers manufactured by Nippon Electric Glass Co., Ltd. and Pacific Materials Co., Ltd. <Pulp> The pulp can be beaten or unbeaten. From the viewpoint of easily obtaining the desired flexural strength and impact strength, beaten pulp is preferred, more preferably pulp with a freeness (CSF) of 50–400 mL, and even more preferably 100–150 mL, as determined by the Canadian Standard Filterability Method (JIS P 8121-2:2012). In the manufacture of forming sheets, from the viewpoint of easily obtaining the desired yield, when using the cylinder papermaking method described later, pulp with a CSF of 100–150 mL is preferred, and when using the flow-on papermaking method, pulp with a CSF of 150–400 mL is preferred. A wide variety of pulps can be used as paper pulp. Examples of pulps include coniferous trees, broad-leaved trees, Manila hemp, Daphne odora, Broussonetia papyrifera, Sedum aizoon, Gynostemma pentaphyllum, mulberry, rice straw, bamboo, reeds, Sabai grass, Lagerstroemia indica, thatch, sugarcane bagasse, sisal, kenaf, cotton lint, bananas, and waste paper. Examples of the aforementioned coniferous trees include those from the Taxodiaceae, Pinaceae, Cupressaceae, and Araucariaceae families. Examples of the aforementioned broad-leaved trees include those from the Ulmaceae, Fagaceae, Myrtaceae, Cercidiaceae, Oleaceae, Rutaceae, Betulaceae, Aceraceae, Juglandaceae, Shinanoaceae, Araliaceae, Annonaceae, Celastraceae, Apocynaceae, Verbenaceae, Gynostemma pentaphyllum, and Sterculiaceae families. These pulps can be bleached or unbleached. The aforementioned pulps can be used alone or in combination of two or more types. This type of pulp is available on the market; for example, Cellofiber manufactured by Paltec Inc. is a commercially available product. <Other Components> The molded slab may optionally further contain one or more substances selected from the group consisting of mica, fly ash, and silica fume. When the molded slab contains mica and / or silica fume, the content or total content relative to the total mass of the molded slab is preferably 2-14% by mass, more preferably 2-10% by mass, more preferably 3-10% by mass, and even more preferably 4-8% by mass. In this embodiment, it is preferable to replace a portion of the cement with mica and / or silica fume. If the molded slab contains mica, it is easier to exhibit a smaller dimensional change rate and improved flame retardancy (i.e., reduced total calorific value). If the molded slab contains silica fume, it is easier to exhibit higher flexural strength in the molded slab. This is believed to be because silica fume also participates in the pozzolanic reaction, and due to the fine particle size of silica fume, it is easier to achieve a dense filling effect on the cement matrix. On the other hand, if the content of silica fume increases, the viscosity of the hardening components tends to increase, and the workability in the cylinder screen process tends to decrease. By keeping the content of silica fume relative to the total mass of the formed plate at less than 10% by mass, good workability in the cylinder screen process can be easily ensured. When the formed plate contains fly ash, its content relative to the total mass of the formed plate is preferably 10-30% by mass, more preferably 15-25% by mass. In this embodiment, from the viewpoint of effective utilization of recycled raw materials and / or cost reduction, it is preferable to use fly ash to replace a portion of the material that does not participate in the pozzolanic reaction. Furthermore, if the formed plate contains fly ash, the fly ash will also participate in the pozzolanic reaction, thus making it easier for the formed plate to exhibit better long-term strength and higher flexural strength. From the viewpoint of easily obtaining the desired dimensional change rate and flexural strength, mica is preferably processed through a sieve of 30–200 mesh in JIS sieve tests, more preferably through a sieve of 40–120 mesh, and particularly preferably through a sieve of 60–80 mesh. As fly ash, types I (Brian specific surface area ≥ 5000), II (Brian specific surface area ≥ 2500), III (Brian specific surface area ≥ 2500), or IV (Brian specific surface area ≥ 1500) as specified in JIS A6201:2015 can be used. As silica ash, silica ash as specified in JIS A 6207:2016 can be used. Generally, the average particle size of silica ash is 0.1–0.5 μm. Mica, fly ash, and silica ash are commercially available. Examples of commercially available mica include mica manufactured by Pakistan International Corporation (PIC). Examples of commercially available fly ash include Finash, FOCAC fly ash, and Eco Ash manufactured by Sitek Industrial Co., Ltd. Examples of commercially available silica ash include EFACO manufactured by PIC. <Any Additives and Additives> The molded sheet may further contain one or more arbitrary additives and additives. To improve yield in the manufacturing method using the molded sheet copying method described later, it is preferable to add an aqueous solution of an anionic polymeric coagulant at a concentration of 0.5 to 2 g / L to the curing component. In this case, the concentration of the anionic polymeric coagulant in the curing component is preferably added at 50 to 250 ppm / solid component, more preferably 75 to 175 ppm / solid component, and even more preferably 100 to 150 ppm / solid component. An example of an anionic polymeric coagulant is IK Flock T210 manufactured by Nippon Giken Co., Ltd. <Manufacturing Method of the Formed Plate> The formed plate of the present invention is preferably manufactured by a sheet forming method. The sheet forming method involves filtering out a slurry (hardening component) in which solids such as cement are suspended in an aqueous medium using a wire mesh, and then forming the filtered sheet. The sheet forming method includes rotary screen forming (Hatschek process) or long-wire forming, where the filtered sheet is sequentially deposited onto a forming roller until a desired thickness is achieved to obtain the formed plate; and flow forming, where a thick slurry is supplied to a felt and sequentially deposited onto a forming roller one to several times until a desired thickness is achieved to obtain the formed plate. From the viewpoint of easily obtaining a uniform formed plate and easily adjusting the thickness, the rotary screen forming method or the long-wire forming method is preferred; from the viewpoint of mass production, the rotary screen forming method is preferred. The manufacturing method of cylinder papermaking typically includes: a step of preparing a curing composition by mixing a non-volcanic ash reaction substance, cement, synthetic fibers, pulp and water, and other aforementioned components, optional additives and auxiliaries as needed; a step of obtaining a paper sheet using the curing composition obtained by cylinder papermaking, and a step of stacking the paper sheet until the desired thickness is achieved; a step of applying pressure to the stacked paper sheet to press out the lye; and a step of curing the pressed sheet. There are no particular limitations on the method for preparing the hardening composition. The components can be mixed using known or conventional mixing methods such as mixers to prepare the hardening composition. Examples of mixing methods include mixers with high stirring performance, such as vertical mixers, blade mixers, spiral mixers, cone mixers, and stirrer mixers used in papermaking. There is no particular limitation on the mixing order of the components, but from the viewpoint of easily obtaining a hardened composition in which the solid components are evenly dispersed, it is preferable to: add the pulp to water and stir, then add the substances that do not participate in the pozzolanic reaction, cement and any other components, additives and auxiliaries in any order and stir, and finally add the synthetic fibers. The concentration of solid components in the curing composition is typically 55–6% by mass, preferably 40–8% by mass, and even more preferably 25–10% by mass. Relative to the total mass of the solid components of the hardening composition, i.e., relative to the total mass of components other than water in the hardening composition, preferably, the amount of substances not participating in the pozzolanic reaction is 35-70% by mass (preferably 40-67.5% by mass, more preferably 45-65% by mass), the amount of cement is 20-61.5% by mass (preferably 25-60.5% by mass, more preferably 30-59.5% by mass), the amount of synthetic fiber is 1-3% by mass (preferably 1-2% by mass, more preferably 1-1.5% by mass), and the amount of pulp is 2.5-7% by mass (preferably 2.5-6% by mass, more preferably...). The amount of mica is 0-10% by mass (e.g., 2-10% by mass, 4-8% by mass), the amount of fly ash is 0-30% by mass (e.g., 10-30% by mass, 15-25% by mass), the amount of silica fume is 0-14% by mass (e.g., 2-14% by mass, 0-10% by mass, 2-10% by mass, 3-10% by mass, 4-8% by mass), and the amount of any additives and auxiliaries is 0-3% by mass (in the case of aqueous solutions of anionic polymeric coagulants, e.g., 50-250 ppm, 75-175 ppm, 100-150 ppm). Next, the curing composition is fed into the feed trough of the wet papermaking machine. The solid content concentration of the curing composition is typically adjusted to approximately 10–1% by mass (preferably 8–3% by mass) using circulating process water. The curing composition supplied from the feed trough to the drum is formed into a sheet by the rotation of the rotary screen under internal negative pressure within the drum, and then conveyed to the forming rollers. The forming rollers are used to stack the sheet to achieve the desired thickness, and the stacked sheet is then cut to a predetermined length. In a preferred embodiment, the yield of the papermaking step is preferably 85% or higher, more preferably 90% or higher. If the yield is above the aforementioned lower limit, it is easier to obtain higher flexural strength, interlayer bonding strength, and / or lower dimensional change rate. The yield can be adjusted to above the aforementioned lower limit by adjusting the Bryan surface area of ​​the non-pozzle reactants, adjusting the freeness of the pulp, and / or selecting the screen size of the cylinder sieve. From the viewpoint of easily achieving both yield and productivity, the screen size of the cylinder sieve is preferably 45 to 55 screens per inch. The yield in the papermaking step can be obtained by the method described in the embodiments described later. As described above, the molded board of the present invention comprises 35-70% by mass of a substance that does not participate in the pozzolanic reaction, 20-61.5% by mass of cement, 1-3% by mass of synthetic fiber, and 2.5-7% by mass of pulp. In cases where the proportions of the components in the curing composition remain unchanged when the molded board can be manufactured by a paper-making process, the proportions of each component in the curing composition can be used as the proportions of each component in the molded board. This is, for example, when the yield in the paper-making step is preferably 85% or higher (more preferably 90% or higher). In this case, the molded plate of the present invention is a porous molded plate, which is based on a hardening composition comprising 35-70% by mass of a substance that does not participate in the pozzolanic reaction, 20-61.5% by mass of cement, 1-3% by mass of synthetic fiber, and 2.5-7% by mass of pulp. In the pore size distribution of the molded plate obtained by mercury intrusion porosimetry, the ratio (B) / (A) of the pore volume (B) in the range of 6-560 nm to the pore volume (A) in the range of 660-9100 nm is 1.70-6.0. The hardening composition may further comprise other components (selected from one or more substances from the group consisting of mica, fly ash, and silica fume) in the same proportion as the other components in the molded plate described above, and may further comprise any additives and auxiliaries in the above proportions. The number of sheets in a laminated sheet depends on the concentration of the solid components of the curing agent and the thickness of the molded sheet. However, when the thickness of the molded sheet is about 6 mm, the number of sheets is usually 12 to 18. Next, the cut sheet is pressed by applying pressure using a press to extract the liquid. The pressure applied by the press is preferably 2–30 MPa, more preferably 7–27 MPa, and particularly preferably 15–25 MPa. The pressure application time is typically 10–60 minutes, preferably 15–50 minutes, and more preferably 20–40 minutes. If the pressure and the pressure application time are within the aforementioned ranges, the desired porosity ratio (B) / (A) is easily obtained in the formed sheet, resulting in high flexural strength and low dimensional stability. Subsequently, the pressed sheets are cured. Hardening occurs through curing. Hardening is due to the hydration reaction (setting reaction) of the cement components, but if the moisture in the sheet evaporates, the hydration reaction of the cement components is inhibited, and hardening may not occur. Therefore, as a primary curing process, curing is carried out in a high-humidity environment where the moisture in the sheet does not evaporate, i.e., at a relative humidity preferably 30-100%, more preferably 50-100%, further preferably 65-100%, further preferably 80-100%, and especially preferably 90-100% (e.g., 100%). As a secondary curing process, the sheets are placed in a waterproof container or bag, or sandwiched between plastic sheets, plastic films (polyethylene sheets, etc.), or metal plates, in a high-humidity environment (preferably 30-100%, more preferably 40-90%, further preferably 50-80%), thereby creating a state where the moisture in the sheet is less likely to evaporate, and curing is then carried out. There is no particular limitation on the aging temperature. The primary aging temperature is, for example, 10–90°C, preferably 30–80°C, and even more preferably 40–80°C. The aging temperature can be changed during the process within the aforementioned range. The secondary aging temperature is, for example, 10°C–70°C, preferably 20°C–50°C. The primary aging time depends on the composition of the curing component and the aging temperature, but is typically 6 to 48 hours, preferably 8 to 36 hours, and more preferably 12 to 24 hours. The secondary aging time is typically 1 to 14 days. Furthermore, as a secondary aging process, water aging can also be carried out. In this case, the water temperature is usually 10–30°C, and the aging time is 8 hours to 13 days. After water aging at a temperature of 10–30°C for 4 hours to 24 hours, the secondary aging process described in the previous paragraph can be carried out for 2 to 13 days. A shaped sheet is obtained by drying after a second curing process. The drying method is not particularly limited as long as it produces a uniformly dried shaped sheet. Typically, the equilibrium moisture content of the shaped sheet (e.g., the moisture content reached after storing the shaped sheet in a well-ventilated room for more than 7 days) is about 6% to about 10% by mass; therefore, it is dried to achieve the same level of moisture content as the equilibrium moisture content. The moisture content and equilibrium moisture content of the shaped sheet can be easily determined using a Kett moisture meter. Alternatively, the dried shaped sheet can be weighed (W... 1) After that, weigh (W) 2) The formed plate, dried to constant weight in an air dryer with a stirrer at 105°C, is obtained by the following formula. {(W 1-W 2) / W 2}×100 The molded plate obtained after drying has a ratio (B) / (A) of 1.70 to 6.0 as described above. Furthermore, all embodiments and preferred embodiments of the molded plate described herein can be considered as embodiments and preferred embodiments of the molded plate obtained after drying. The thickness of the forming plate of this invention depends on its application, for example, it is 3 to 30 mm. When the forming plate is used as, for example, wall material, the thickness of the forming plate is preferably 4 mm or more and 20 mm or less; when used as floor material, the thickness of the forming plate is preferably 8 mm or more and 30 mm or less. Furthermore, there is no particular upper limit to the thickness of the forming plate, but it is suitable to be around 15 mm in the rotary screen papermaking method and around 50 mm in the long screen papermaking method. The thickness of the forming plate can be appropriately determined by adjusting the number of sheets of papermaking material in the laminate and / or the thickness of the sheet after liquefaction. The thickness of the forming plate can be determined by a general method, for example, by measuring the thickness at multiple locations using a digital diameter gauge and obtaining the average value. The longitudinal and transverse dimensions of the forming plate of the present invention depend on the dimensions of the papermaking machine and the pressing machine, for example, they can be 3×6 feet (910mm×1820mm), 4×8 feet (1210mm×2440mm), or 4×10 feet (1210mm×3030mm). Of course, smaller forming plates with desired dimensions can also be cut from such large-sized forming plates. The bulk density of the molded plate of the present invention, as measured according to JIS A 5430:2018, is, for example, 1.45 to 1.8 g / cm³. 3 The preferred concentration is 1.50–1.75 g / cm³. 3 The optimal concentration is 1.55–1.75 g / cm³. 3 If the bulk density is within the aforementioned range, the desired dimensional change rate, flexural strength, interlaminar bonding strength, and / or flame retardancy can be easily obtained. The bulk density can be adjusted to the aforementioned range by adjusting the types of the four components, the blending ratio of the four components, the pressing pressure, and / or the pressing time. The flexural strength of the formed plate of the present invention during drying, as measured according to JIS A 1408:2017, is preferably 10 N / mm. 2 The above is preferred to be 15 N / mm. 2 The above is further preferred to be 20 N / mm. 2The flexural strength during drying can be adjusted above the aforementioned lower limit by, for example, adjusting the Blaine surface area of ​​the material that does not participate in the volcanic ash reaction, the blending ratio of the aforementioned four components, the pressing pressure, and / or the pressing time. There is no particular upper limit to the flexural strength during drying, but it is typically 50 N / mm². 2 The following describes the preferred bending strength of the molded sheet of the present invention when absorbing water, as measured according to JIS A 1408:2017, is 5 N / mm. 2 The above is preferred to be 10 N / mm. 2 The above is further preferred to be 15 N / mm. 2 The above applies. The flexural strength during water absorption can be adjusted above the aforementioned lower limit by, for example, adjusting the Blaine surface area of ​​the material that does not participate in the volcanic ash reaction, the blending ratio of the aforementioned four components, the pressing pressure, and / or the pressing time. There is no specific upper limit for the flexural strength during water absorption, but it is typically 35 N / mm². 2 the following. The dimensional change rate (length change rate) of the molded plate of the present invention, as measured according to JIS A 5430:2018, is preferably 0.150% or less, more preferably 0.130% or less, and particularly preferably 0.100% or less. The dimensional change rate can be adjusted to below the aforementioned upper limit value by, for example, adjusting the Blaine surface area of ​​the material that does not participate in the volcanic ash reaction, the blending ratio of the aforementioned four components, the pressing pressure, and / or the pressing time. The inventors of this invention have discovered that the molding sheet of the present invention has a low water absorption rate. A low water absorption rate is preferable because the dimensions of the molding sheet are less susceptible to variations due to changes in the environment in which it is used (e.g., season, region, and / or usage environment). Furthermore, the increased flexural strength of the molding sheet during water absorption is also preferable. The water absorption rate of the molding sheet of the present invention, as measured according to JIS A 5430:2018, is preferably 28% or less, more preferably 26% or less, further preferably 24% or less, even more preferably 22% or less, and particularly preferably 20% or less. The lower limit of the aforementioned water absorption rate is not limited, but is preferably 15% or more. The water absorption rate can be adjusted to be above the aforementioned lower limit and below the aforementioned upper limit by, for example, adjusting the proportion of pulp, adjusting the Brønsted surface area of ​​substances that do not participate in the pozzolanic reaction, and adjusting the pressing pressure and / or pressing time. The total calorific value of the formed plate, as determined by the exothermic test according to JIS A 5430:2018, is preferably 8.0 MJ / m³. 2 Below, 7.0 MJ / m is preferred. 2The following is a further preferred value: 6.0 MJ / m 2 Below. If the total calorific value is below the aforementioned upper limit, the flame retardancy of the formed plate is higher. The aforementioned lower limit for total calorific value is not specified; for example, it is 4.0 MJ / m³. 2 The above. The total calorific value is adjusted to below the aforementioned upper limit by, for example, reducing the proportion of organic matter (pulp and synthetic organic fibers) in the forming board and / or adjusting the ratio (B) / (A). The dry impact strength (type 1 test piece, unnotched) of the molded sheet, as measured according to JIS K 7111-1:2012 "Method for determination of impact properties of plastics - saponins", is preferably 1.5 kJ / m. 2 The above is preferred to be 1.8 kJ / m 2 The above is further preferred to be 2.1 kJ / m 2 The impact strength during drying can be adjusted above the aforementioned lower limit by, for example, pressing pressure and / or pressing time. There is no specific upper limit for the impact strength during drying, but it is typically 7 kJ / m². 2 The following is a standard standard: The impact strength of the molded sheet during water absorption (type 1 test piece, no notch) as measured according to JIS K 7111-1:2012 "Method for determination of impact properties of plastics - sapphire" is preferably 2 kJ / m. 2 The above is preferred to be 2.5 kJ / m 2 The above is further preferred to be 3.0 kJ / m 2 The impact strength during water absorption can be adjusted above the aforementioned lower limit by, for example, pressing pressure and / or pressing time. There is no specific upper limit to the impact strength during water absorption, but it is typically 10 kJ / m². 2 the following. The optimal interlayer bonding strength of the formed sheet during drying is 1.5 N / mm. 2 The above is preferred to be 2.0 N / mm. 2 The above is further preferred to be 2.5 N / mm. 2The above applies. If the interlayer adhesion strength during drying is above the aforementioned lower limit, it is preferable to prevent interlayer delamination during use. The interlayer adhesion strength during drying can be adjusted to be above the aforementioned lower limit by, for example, adjusting the Blaine surface area of ​​the material that does not participate in the volcanic ash reaction, the pressing pressure, and / or the pressing time. There is no particular upper limit to the interlayer adhesion strength during drying, but it is typically 6 N / mm². 2 The optimal interlayer bonding strength of the molded sheet during water absorption is 0.2 N / mm. 2 The above is preferred to be 0.3 N / mm. 2 The above is further preferred to be 0.5 N / mm. 2 The above applies. If the interlayer adhesion strength during water absorption is above the aforementioned lower limit, it is preferable to prevent interlayer delamination during use. The interlayer adhesion strength during water absorption can be adjusted to be above the aforementioned lower limit by, for example, pressing pressure and / or pressing time. There is no particular upper limit to the interlayer adhesion strength during water absorption, but it is typically 3 N / mm. 2 The interlayer adhesion strength of the molded sheet during drying or water absorption can be determined using the methods described in the examples below. [Examples] The present invention will now be described in more detail by way of examples, but the invention is not limited by these examples. The physical properties in the examples and comparative examples were measured or evaluated by the following procedures. [Pore Volume] Two test pieces, approximately 1 cm square, were cut from the molded plate. After drying at 105℃±5℃ for at least 12 hours, they were placed in a desiccator conditioned with silicone and kept at 20℃±1.5℃. The pore size distribution of these test pieces was determined using a mercury intrusion porosimetry (Made by Micromeritics, "MicroActive AutoPore V 9600") apparatus. Based on the Log differential pore volume obtained from the pore size distribution, the pore volume (A) in the 660–9100 nm range and the pore volume (B) in the 6–560 nm range for each test piece were calculated. The ratio of pore volume (B) to pore volume (A) for each test piece was calculated using the following formula, and their average value was taken as the pore volume ratio (B) / (A) of the molded plate. Pore ​​volume ratio (B) / (A) = {pore volume (B) in the range of 6–560 nm} / {pore volume (A) in the range of 660–9100 nm} [Thickness] The thickness of the forming plate was measured at 6 points using a digital diameter gauge, and the average value of these measurements was taken as the thickness of the forming plate. [Bulk Density] Bulk density was determined according to JIS A 5430:2018. Specifically, four strips, approximately 180 mm in length and 50 mm in width, were cut from the molded plate. These strips were then placed in an air dryer equipped with a stirrer and dried at 105°C ± 5°C for 24 hours. The removed strips were then placed in a desiccator conditioned with silicone and allowed to stand at 20 ± 1.5°C. The mass and volume of each strip were measured, and the bulk density was calculated. The average of these values ​​was taken as the bulk density of the molded plate. [Flexural Strength] Eight strip-shaped test pieces, approximately 180 mm in length and 50 mm in width, were cut from the molded plate being tested. To determine the flexural strength during drying, four test pieces were first dried in an air dryer with a stirrer set to 40°C for 72 hours. Then, the removed test pieces were placed in a desiccator conditioned with silicone and placed at 20 ± 1.5°C. The flexural strength of each test piece was determined according to JIS A 1408:2017, and their average value was used as the flexural strength of the molded plate during drying. To determine the flexural strength during water absorption, four test pieces were first immersed in water at 20°C for 72 hours. Then, the test pieces were removed, the water adhering to the surface was wiped off, and the flexural strength of each test piece was immediately determined according to JIS A 1408:2017, and their average value was used as the flexural strength of the molded plate during water absorption. The flexural strength under dry and water absorption conditions was measured using an Autograph AG50kNX manufactured by Shimadzu Corporation, under a central load condition with a flexural span of 14.6 cm and a test speed (load head speed) of 20 mm / min. [Impact Strength] Six Type 1 test pieces according to JIS K 7111-1:2012 were cut from the molded plate. To determine the impact strength during drying, three test pieces were first dried in an air dryer with a stirrer set to 40°C for 72 hours. Then, the removed test pieces were placed in a desiccator conditioned with silicone and placed at 20±1.5°C. The impact strength (unnotched) of each test piece was determined according to JIS K 7111-1:2012, and their average value was used as the impact strength of the molded plate during drying. To determine the impact strength during water absorption, three test pieces were first immersed in water at 20°C for 72 hours. Then, the test pieces were removed, the water adhering to the surface was wiped off, and the impact strength (unnotched) of each test piece was immediately determined according to JIS K 7111-1:2012, and their average value was used as the impact strength of the molded plate during water absorption. The impact strength during drying and water absorption was measured using a Sapphire (digital) impact testing machine, type DG-CB, manufactured by Toyo Seiki Co., Ltd. [Dimensional Change Rate] The dimensional change rate (length change rate) of the molded plate was determined according to JIS A 5430:2018. Specifically, three strip-shaped test pieces, approximately 160 mm in length and 50 mm in width, were cut from the molded plate being tested. These test pieces were then placed in a dryer, and the temperature inside the dryer was maintained at 60°C ± 3°C for 24 hours. The test pieces were then removed and placed in a desiccator conditioned with silicone, and placed at 20 ± 1.5°C. Next, opaque glass was attached to each test piece, and markings were made with a spacing of approximately 140 mm between the markings. The length between the markings was measured using a comparator with an accuracy of 1 / 500 mm, and this length was taken as L. 1 (mm). Then, the laminated plate was erected with its length horizontal, so that the upper end of the laminated plate was approximately 30 mm below the water surface, and immersed in water at 20℃ ± 1.5℃. After 24 hours, the test piece was removed from the water, the water adhering to the surface was wiped off, and the length between the marks was measured again. This length was taken as L. 2 (mm). The dimensional change rate (%) of water absorption is calculated for each test piece using the following formula, and the average of these values ​​is used as the dimensional change rate of the molded plate. Dimensional change rate of water absorption = {(L...} 2-L 1) / L 1}×100 [Water Absorption Rate] The water absorption rate of the molded sheet was determined according to JIS A 5430:2018. Specifically, four strip-shaped test pieces, approximately 180 mm in length and 50 mm in width, were cut from the molded sheet and immersed in water at 20℃±1.5℃. After 24 hours, the test pieces were removed, the water adhering to the surface was wiped off, and the mass of each test piece (the mass of the test piece at the time of water absorption, W) was immediately measured. 3). Next, these test pieces were placed in a dryer equipped with a stirrer and set to 105℃±5℃. After drying for 24 hours, they were removed and placed in a desiccator conditioned with silicone, then allowed to cool to room temperature (20℃±1.5℃). Then, the mass of each test piece (mass W of the test piece at the time of drying) was measured. 0). Calculate the water absorption rate (%) of each test piece using the following formula, and use their average value as the water absorption rate of the molded plate. Water absorption rate = {(W 3-W 0) / W 0}×100 [Interlaminar Bond Strength] Eight test pieces, approximately 40 mm × 40 mm, were cut from the molded sheet. To determine the interlaminar bond strength during drying, firstly, steel jigs, approximately 40 mm × 40 mm in size, were attached to the surface and back of four air-dried test pieces using an epoxy resin adhesive. These were left at room temperature for at least 24 hours to allow the epoxy resin adhesive to harden and achieve sufficient bond strength. Then, they were dried in an air dryer equipped with a stirrer at 40°C for 72 hours. For each test piece, a Shimadzu Autograph AG5000-B was used to apply a tensile test perpendicular to the bonded surface at a speed of 0.5 mm / min, and the maximum tensile load was recorded. The interlaminar bond strength of each test piece was calculated by dividing the maximum tensile load by the area of ​​the test piece, and the average of these values ​​was used as the interlaminar bond strength of the molded sheet during drying. To determine the interlayer bond strength during water absorption, firstly, steel clamps measuring approximately 40mm x 40mm were bonded to the surface and back of four air-dried test pieces using an epoxy resin adhesive. The pieces were then left at room temperature for at least 24 hours to allow the epoxy resin adhesive to harden. Next, the test pieces were immersed in water at 20°C for 72 hours. After removing the test pieces and wiping off any water, a Shimadzu Autograph AG5000-B was immediately used to apply a tensile load perpendicular to the bonded surface at a speed of 0.5mm / min. The maximum tensile load was recorded. The interlayer bond strength of each test piece was calculated by dividing the maximum tensile load by the area of ​​the test piece, and the average of these values ​​was taken as the interlayer bond strength of the molded board during water absorption. [Yield in the Papermaking Step] The yield in the papermaking step (the step of preparing the slurry using a cylinder screen) of each embodiment and comparative example was determined. Specifically, the slurry placed into the cylinder screen was scooped up and its mass was measured (A1). The solid components were collected by filtering using a filtration device (Nutsche filter and suction bottle), dried in a dryer at 105°C for more than 12 hours until the dried mass became constant, and the mass of the solid components was measured (B1). The concentration C of the slurry placed into the cylinder screen was calculated using the following formula. 1. Concentration C 1 = (B1 / A1) × 100 Similarly, scoop out the slurry after passing through the circular screen and calculate its concentration C using the following formula. 2. Concentration C 2 = (B2 / A2) × 100 Here, A2 is the mass of the slurry scooped through the cylinder screen, and B2 is the mass of its solid components. The yield in the papermaking process is obtained by the following formula: Yield (%) in the papermaking process = {(C 1-C 2) / C 1}×100 [Total Calorific Value] The total calorific value was determined using the calorific value test according to JIS A 5430:2018. Specifically, two test pieces (99±1 mm square) were cut from the forming plate and held at 23℃±2℃ and 50±5% relative humidity until they reached a fixed mass before the calorific value test was performed. The heating time was set to 20 minutes. The average total calorific value of each test piece was used as the total calorific value of the forming plate. The fibers shown in Table 1 below were used in the examples and comparative examples. [Table 1] Table 1: Fibers used in the examples and comparative examples [Example 1] Pulp (NBKP, Paltex Corporation Cellofiber, CSF value: 115 mL) was dispersed in water. Heavy calcium carbonate (Brian specific surface area: 4000 cm³) was added to the resulting dispersion. 2 / g) and ordinary Portland cement (manufactured by Pacific Cement Corporation: ordinary Portland cement) were mixed. Polyvinyl alcohol fiber 1 (referred to as "PVA1" in Table 2) was added to the resulting mixture and further mixed. The proportions of each component are shown in Table 2, resulting in a hardening composition with a solid content concentration of 16% by mass. The resulting hardening composition was fed into the feed trough of a metering device and fed from the feed trough to a cylinder screen. The solid content concentration of the hardening composition was adjusted to 4% by mass using process circulating water, and papermaking was performed using a Mini-Hatschek Machine. Then, the papermaking sheet obtained in the step of making 15 cylinder screens was pressed for 20 minutes while applying a pressure of 21.6 MPa to the laminated papermaking sheet to extract the liquor. The extruded sheet was cured in a constant temperature and humidity curing apparatus at 50°C and 98% saturated humidity for 24 hours. Then, it was wrapped with a covering sheet and cured for 13 days at 20°C and 60% humidity (total curing time 14 days). The sheet without the covering sheet was then dried in a drum dryer set to 120°C for 2 hours to obtain a shaped sheet. Various measurements and evaluations were performed on the obtained shaped sheet. The results are shown in Table 2. In Table 2, the values ​​for flexural strength, impact strength, and interlaminar adhesion strength are listed in pairs for each embodiment; the upper value represents the value during drying, and the lower value represents the value during water absorption. [Examples 2-17 and Comparative Examples 1-3] Except that the components were used in the proportions shown in Table 2, molded plates were obtained in the same manner as in Example 1, and various measurements and evaluations were performed on the obtained molded plates. The results are shown in Tables 2 and 3. In Example 10, a Bryan specific surface area of ​​2500 cm² was used at a mass ratio of 50:50. 2 / g of heavy calcium carbonate and a specific surface area of ​​6200 cm² 2 / g of heavy calcium carbonate is used as calcium carbonate. Therefore, the Blaine specific surface area of ​​calcium carbonate in Example 10 is calculated to be 4500cm². 2 / g (=2500×0.5+6500×0.5). Furthermore, in the examples of blending fly ash or silica fume, fly ash or silica fume was also added when ordinary Portland cement was added. [Example 18] Except for using PVA2 instead of PVA1 and changing the pressing pressure from 21.6 MPa to 7.85 MPa, a molded plate was obtained in the same manner as in Example 1, and various measurements and evaluations were performed on the obtained molded plate. The results are shown in Table 2. [Table 2] Table 2: Composition and Results [Table 3] Table 3: Composition and Results As shown in Table 2, the molded board containing substances that do not participate in the pozzolanic reaction, cement, synthetic fibers, and pulp in a specific ratio, and having a specific pore volume ratio (B) / (A), exhibits high flexural strength and low dimensional change rate. On the other hand, as shown in Table 3, Comparative Example 1, where the molded board does not have a specific pore volume ratio (B) / (A), shows lower flexural strength and higher dimensional change rate than the corresponding Examples (Examples 1-4). Furthermore, Comparative Example 1 shows low interlayer adhesion strength and low yield in the papermaking process. Comparative Example 2, where the molded board does not contain the components in a specific ratio, shows lower flexural strength than the corresponding Examples (Examples 1 and 5). Furthermore, Comparative Example 2 shows low interlayer adhesion strength. Comparative Example 3, where the molded board does not contain the components in a specific ratio and does not have a specific pore volume ratio (B) / (A), shows lower flexural strength and higher dimensional change rate than the corresponding Examples (Examples 1 and 5). Furthermore, in Comparative Example 3, it can be seen that the interlayer bonding strength is low and the total heat generation is high. Furthermore, the impact of the proportion of any component of silica fume on the formability during the rotary screen manufacturing process was visually evaluated using the following evaluation criteria: A: No droplets of the hardening component from the rotary screen during the forming process; B: One droplet of the hardening component from the rotary screen per 30cm of screen width during the forming process; C: More than two droplets of the hardening component from the rotary screen per 30cm of screen width during the forming process [Table 4]. [Potential for industrial application] The molded plate of the present invention has high flexural strength and low dimensional change rate. Such a molded plate of the present invention can be used as a building material (e.g., ceiling material, interior material, exterior material, floor material) or civil engineering material. none none. none.

Claims

1. A molded board, comprising 35-70% by mass of a substance that does not participate in the pozzolanic reaction, 20-61.5% by mass of cement, 1-3% by mass of synthetic fiber, and 2.5-7% by mass of pulp, wherein in the pore size distribution of the molded board obtained by mercury intrusion porosimetry, the ratio (B) / (A) of the pore volume in the range of 6-560 nm to the pore volume in the range of 660-9100 nm is 1.70-6.0; wherein the total content of synthetic fiber and pulp is 7% by mass or less relative to the total mass of the molded board.

2. The molded plate as claimed in claim 1, wherein the substance that does not participate in the volcanic ash reaction is selected from one or more substances in the group consisting of calcium carbonate, silica powder and talc.

3. The forming plate as requested in item 2, wherein the calcium carbonate is heavy calcium carbonate.

4. The shaped plate of claim 1 further comprises one or more substances selected from the group consisting of mica, fly ash and silica ash.

5. The molded plate as requested in item 1, wherein the average fiber diameter of the synthetic fibers is less than 50 μm.

6. The molded plate of claim 5, wherein the average fiber diameter of the synthetic fibers is 5 μm or more and 40 μm or less.

7. The molded sheet as requested in item 1, wherein the aspect ratio of the synthetic fibers is 150 or more and 1000 or less.

8. The molded sheet of claim 1, wherein the synthetic fiber is selected from at least one of the group consisting of polyvinyl alcohol fibers, polyethylene fibers, polypropylene fibers, acrylic fibers, polyaramid fibers and nylon fibers.

9. The molded sheet as requested in item 1, wherein the water absorption rate, as determined in accordance with JIS A 5430:2018, is 15% or more and 28% or less.

10. The molded plate as requested in item 1, wherein the total calorific value determined by the exothermic test in accordance with JIS A 5430:2018 is less than 8.0 MJ / m2.

11. The molded plate of claim 1, wherein the bulk density measured in accordance with JIS A 5430:2018 is 1.50 g / cm3 or higher.

12. The molded sheet of claim 1, wherein the flexural strength upon water absorption, as measured in accordance with JIS A 1408:2017, is 15 N / mm² or higher.

13. The molded sheet as requested in item 1, wherein the water absorption rate, as determined in accordance with JIS A 5430:2018, is less than 26%.

14. The formed plate of claim 1, wherein the pore volume (B) is less than 2.50 mL / g.