JP2010125694A - Manufacturing method of inorganic paper-making plate - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a manufacturing method of an inorganic paper-making plate wherein bending caused by weight is not large even in a thick product, handling is excellent at transportation and processing, processability is favorable, and a fire-proofing property is excellent, namely total heat generation in a heat generation test for 20-minute heating by the use of a test machine regulated in a JIS A 5430 appendix is low. <P>SOLUTION: The manufacturing method of an inorganic paper-making plate comprises steps for: wet-blending a composition comprising 30 to 70 mass% of a hydrate material for forming a matrix, 3 to 9 mass% of natural fiber and a fiber length of 6.0 to 0.2 mm having a water-filtration degree of 150 to 450 ml under Canadian standard freeness and 0.5 to 5 mass% of inorganic and/or synthetic fiber (excepting asbestos) having a fiber diameter of 10 to 50 μm provided that a total mass% of the natural fiber and the inorganic and/or synthetic fiber is 3.5 to 12 mass%, 5 to 30 mass% of a calcium silicate hydrate having an average particle size of 30 to 100 μm obtained previously by synthesis by water-vapor heating, 5 to 20 mass% of Wollastonite and 1 to 15 mass% of an inorganic filler, whereby slurry is obtained, then paper-making the obtained slurry to give a raw plate, and then dehydrating the raw plate at the holding pressure of 16 to 40 N/mm<SP>2</SP>, and aging and curing it, whereby a cured material having a thickness of 2 to 5 mm and the apparent density of 1.2 to 1.5 g/cm<SP>3</SP>is obtained. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a method for producing an inorganic papermaking plate, and more particularly to a method for producing a thin inorganic papermaking plate.

At present, inorganic boards used as general building materials include, for example, cement-based, gypsum-based, and calcium silicate-based materials. These inorganic plates are usually produced by methods such as papermaking and press molding.
As raw materials for inorganic boards, cement-based, gypsum-based and calcium silicate-based materials usually use matrix forming raw materials and fiber raw materials as essential raw materials, and together with these essential raw materials, an inorganic filler for imparting necessary performance. Used together. Conventionally, asbestos has been used as a fiber raw material. Asbestos is a very suitable fiber for the production and performance of inorganic board, but it has been pointed out that its effects on health. Therefore, asbestos can be manufactured in various ways to produce inorganic board without using asbestos and obtain the required performance. Technology development has been carried out.

  For example, in Non-Patent Document 1, cellulose fiber such as wood pulp is used as a fiber raw material in decalcification of a calcium silicate plate, but using cellulose fiber makes the calcium silicate plate flexible. It is described that it is suitable for curved surface construction and the like.

Further, for example, with respect to a method for producing a fiber-reinforced inorganic plate by a papermaking method, Patent Document 1 discloses a hydrated raw material for forming a matrix of 20 to 60% by mass; an inorganic filler of 1 to 50% by mass; Inorganic fiber and / or synthetic fiber 0.5 in the range of natural fiber 3-11 mass% and fiber length 6.0-0.2 mm, fiber diameter 20-50 μm in the range of 150-450 ml with standard freeness Reinforcing fibers composed of ˜5% by mass (excluding asbestos) 3.5˜12% by mass; and an average particle diameter obtained by hydrothermal synthesis of a calcareous raw material and a siliceous raw material in advance within a range of 30 μm to 100 μm A slurry containing 10 to 50% by mass of calcium silicate hydrate is obtained by wet mixing to obtain a slurry, and the resulting slurry is subjected to a thin film dehydration rate of 5 on an endless felt. The apparent density of the green plate after separation from the making roll is set to 0.35 to 0.65 g by adjusting the moisture content of the thin film when wound on the making roll to 100 to 180% within the range of 30% / second. A green plate is obtained by papermaking within the range of / cm ^3, the green plate is pressure dehydrated, and the apparent density of the green plate after pressure dehydration is 1.3 of the apparent density of the green plate before pressure dehydration. A surface comprising an inorganic papermaking plate obtained by curing and curing after being within a range of ~ 2.0 times, and a moisture-permeable surface decorative layer provided on at least one surface of the substrate The decorative inorganic papermaking board (Claim 1); The surface decorative inorganic papermaking board (Claim 2) according to claim 1, comprising a permeable sealer layer between the base material and the permeable surface decorative layer. The paper making method of the inorganic paper making plate used as a material is the round net paper making method. , Surface decorative inorganic papermaking board according to claim 1, wherein (claim 3) is disclosed. The paragraph [0035] of Patent Document 1 states that “pressure dehydration of the green plate can be performed using a pressure dehydration apparatus such as a known press machine. , Holding pressure, holding time, etc.) must be determined so that the apparent density of the green plate after pressure dehydration is within a range of 1.3 to 2.0 times the apparent density of the green plate before pressure dehydration. As a method for determining the conditions for pressure dehydration, for example, prior to actual production, the raw slurry is dehydrated at 5 to 30% / second by a suction dehydration test simulating papermaking, and the apparent density is 0.35. 0.65 g / to prepare a raw plate of cm ^3, which was tested pressurized dehydration, the apparent density of the apparent density of the raw plate after pressurized dehydration pressurized dehydration before the raw plate 1.3 to 2. The pressure dehydration conditions may be determined so that the pressure is within the range of 0. Therefore, the pressure dehydration conditions are defined as a specific range. But it is not limited to, holding pressure is generally a 5 to 30 N / mm ^2, the product of the holding pressure (N / mm ²⁾ and retention time (in seconds) is approximately at 1000~40000N / mm ² · sec There is also a statement to the effect.

In addition, in the Japanese Patent Application No. 2008-78693, the present inventors have disclosed a hydrated raw material for forming a matrix of 20 to 60% by mass; 3 to 11% by mass of natural fibers having a freeness within the range of 150 to 450 ml in Canadian standard freeness. % And / or fiber length of 6.0 to 0.2 mm and fiber diameter of 20 to 50 μm and / or synthetic fiber (excluding asbestos) of 0.5 to 5% by mass, except natural fiber and inorganic fiber And / or a total amount of synthetic fibers of 3.5 to 12% by mass; calcium silicate hydrate having an average particle diameter in the range of 30 μm to 100 μm obtained by hydrothermal synthesis of a calcareous raw material and a siliceous raw material in advance. 10 to 50% by mass; 1 to 50% by mass of an inorganic filler; and 1 to 20% by mass of a silica fume are wet-mixed to obtain a slurry, and the resulting slurry is made. Providing a raw plate by the after pressure圧脱water said biological plate to 40N / mm ² exceeding holding pressure 30 N / mm ² during pressure dehydration, the thickness 2~4mm by curing curable, apparent density 1. 2~1.5g / cm ³ manufacturing method of thin inorganic papermaking plate, characterized in that to obtain a cured body of (claim 1); width 910 mm, a thin inorganic papermaking plate having dimensions of length 2575mm length direction Deflection due to its own weight when it is supported in a single line at the central part is 500 mm or less due to the difference between the central part and the edge part, and a fiber by a central single-supported three-point bending test using No. 4 test piece defined in JIS A 1408 A method for manufacturing a thin inorganic papermaking plate according to claim 1 (Claim 2) has already been proposed, wherein the maximum deflection in the direction is 15 mm or less and the bending strength in the fiber direction is 25 N / mm ² or more.

Furthermore, as an aqueous coating composition for providing a moisture-permeable coating film on the surface of a concrete structure, for example, Patent Document 2 discloses that a solid content in the aqueous coating composition is 100 parts by weight (parts by mass), and an alkylalkoxysilane is dispersed in water. Body (a) 15-47 parts by weight (parts by mass), fluorine emulsion (b) 8-27 parts by weight (parts by mass), fluorine pendant acrylic polymer (c) 9-27 parts by weight (parts by mass), and pigment (d 1) to 35 parts by weight (parts by mass) of an aqueous coating composition (Claim 1); further comprising 0.1 to 2 parts by weight (parts by mass) of a bioinert agent. The water-based paint composition according to claim 1 or 2, further comprising a polar organic solvent and / or a thickener in a total amount of 3 to 10% by weight (mass%). Composition (Claim 3); Claim 1 to a coating film obtained by coating the aqueous coating composition according to any one of 3, 23 ° C., moisture permeation amount 30 to 40 g / m ² per 24 hours at 50% humidity A moisture-permeable coating film (Claim 4) is disclosed.

Compositions, Vol. 13, no. 2 [April 1982] 123-128 "Developing asbestos-free calcium silicate building boards" JP, 2007-1043, A Claims [0035] JP, 2001-348529, A Claim

  However, the description of Non-Patent Document 1 suggests that the deflection of the calcium silicate plate using cellulose fibers increases, particularly when the thickness of the calcium silicate plate is thin. There was a problem that it was extremely large, warped during construction, and difficult to construct. Also for the surface-decorated inorganic papermaking plate disclosed in Patent Document 1, in the case of a thin object, the deflection due to its own weight is large, the handling property during transportation and construction is poor, and the problem that it is difficult to work has not been solved.

  Therefore, the object of the present invention is that even if it is a thin object, there is little deflection due to its own weight, the handling property during transportation and construction is good, the work is easy, and the nonflammability is excellent, that is, JIS A 5430 Annex JA. An object of the present invention is to provide a method for producing a thin inorganic papermaking plate having a small total calorific value in a heat generation test in a heating time of 20 minutes using a specified test apparatus.

That is, the present invention relates to 30 to 70% by mass of a hydratable raw material for forming a matrix; 3 to 9% by mass of natural fibers having a freeness within the range of 150 to 450 ml in Canadian standard freeness, and a fiber length of 6.0 to 0.00. 0.5 to 5% by mass of inorganic fiber and / or synthetic fiber (excluding asbestos) in the range of 2 mm and fiber diameter of 10 to 50 μm, provided that the total amount of natural fiber and inorganic fiber and / or synthetic fiber is 3.5 to 12% by mass; 5-30% by mass of calcium silicate hydrate having an average particle diameter in the range of 30 μm to 100 μm obtained by hydrothermal synthesis of a calcareous raw material and a silicic acid raw material in advance; Wollastonite 5-20 And a mixture containing 1 to 15% by mass of an inorganic filler is wet-mixed to obtain a slurry, and a green plate is obtained by making the resulting slurry, and the green plate is subjected to pressure dehydration. Holding pressure After pressurizing圧脱water 16~40N / mm ^2, a thickness of 2~5mm by curing curing, thin inorganic papermaking plate, characterized in that to obtain a cured product of an apparent density 1.2~1.5g / cm ³ Related to the manufacturing method.

Furthermore, the manufacturing method of the thin inorganic papermaking sheet according to the present invention has a deflection due to its own weight when it is supported in a straight line at the center in the length direction of the thin inorganic papermaking sheet having a width of 910 mm and a length of 2575 mm. The difference between the central portion and the edge portion is 500 mm or less, and the maximum deflection by the bending test based on JIS A 5430 10.3.2 is used using the No. 3 test piece defined in JIS A 1408 4.1. It is 20-50 mm and the bending strength is 28 N / mm ² or more.

Moreover, the manufacturing method of the thin inorganic papermaking board of this invention is 3-6 mass% of natural fibers, and 0.5-3 mass% of inorganic fibers and / or synthetic fibers, provided that natural fibers and inorganic fibers and / or synthetic fibers are used. The total calorific value in the exothermic test in a heating time of 20 minutes using a test apparatus defined in JIS A 5430 Annex JA of a thin inorganic papermaking sheet is 4 to 4 in the range of 3.5 to 9% by mass. .5 MJ / m ² or less.

  According to the method for producing a thin inorganic papermaking plate of the present invention, even a thin object has little deflection due to its own weight, has good handling properties during transportation and construction, is easy to work with, and has excellent nonflammability. It is possible to produce a thin inorganic papermaking sheet having a small total calorific value in a heat generation test in a heating time of 20 minutes using a test apparatus defined in JIS A 5430 Annex JA.

Hereinafter, the manufacturing method of the thin inorganic papermaking board of this invention is demonstrated in detail.
According to the method for producing a thin inorganic papermaking sheet of the present invention, 30 to 70% by mass of a hydratable raw material for forming a matrix; 3 to 9% by mass of natural fibers having a freeness within a range of 150 to 450 ml in Canadian standard freeness, and fibers 0.5 to 5% by mass of inorganic fiber and / or synthetic fiber (excluding asbestos) in the range of length 6.0 to 0.2 mm and fiber diameter 10 to 50 μm, but natural fiber and inorganic fiber and / or synthetic fiber 3.5 to 12% by mass of the total amount of calcium silicate hydrate having an average particle diameter in the range of 30 μm to 100 μm obtained by hydrothermal synthesis of the calcareous material and the siliceous material in advance 5 to 50% by mass Wollastonite 5-20% by mass; and a mixture containing 1-15% by mass of an inorganic filler by wet mixing to make a slurry, making a slurry, pressurizing dehydration, curing and curing, and thin inorganic matter It can be manufactured concrete plate.

Here, the hydratable raw material for forming the matrix may be either hydraulic or pneumatic, and is not particularly limited, but a hydraulic cement is suitable because of its high strength expression power, for example, Examples include ordinary Portland cement, early-strength cement, blast furnace cement, low heat cement, and ecocement. Examples of the air-cement cement include gypsum-based materials such as hemihydrate gypsum and type II anhydrous gypsum. When a gypsum-based material is used, a predetermined amount of a curing retarder (citric acid, phthalic acid, tartaric acid, etc.) or a curing accelerator (alkali metal sulfate such as sodium sulfate) can be added as necessary. The specific surface area of the matrix-forming water-dispersible material in the case of hydraulic cement, 2500~5000cm ² / g, is preferably in the range of 3000~4000cm ² / g, when the air-hardening cement, 4000～8000Cm ² / G, preferably in the range of 4500 to 6500 cm ² / g.

  The reinforcing fibers include, for example, natural fibers such as wood pulp and various hemp, inorganic fibers such as glass fibers, rock wool, ceramic wool, and carbon fibers, artificial pulp, polyvinyl alcohol, polypropylene, polyethylene, polyester, acrylic, and rayon. Synthetic fibers such as Among these, from the viewpoint of further improving the bending strength and impact resistance performance, it is preferable to use cellulosic fibers such as wood pulp as the main component of the reinforcing fibers. In addition, the freeness of natural fibers is in the range of 150 to 450 ml, preferably 150 to 350 ml in terms of Canadian standard freeness (hereinafter referred to as “CSF”) defined in JIS P 8121. The CSF can be adjusted by beating a reinforcing fiber, such as wood pulp, with a refiner or the like wet. The beating treatment increases the branching of the fibers, so-called fibrillation, and as a result, it is possible to improve adhesion and flexibility with the matrix formed by hydrating the hydratable raw material for matrix formation. . Here, by setting the CSF to 450 ml or less, sufficient adhesion between the reinforcing fiber and the matrix is achieved, good dispersion of the reinforcing fiber is obtained, and high strength is imparted to the product (inorganic papermaking board). Can do. In addition, by making the CSF 150 ml or more, the drainage of the slurry is increased, dehydration unevenness, bulges, burrs, etc. during pressure dehydration are prevented, and good flexibility and consequently impact resistance performance are imparted to the product. Can do.

  In the papermaking method, the fiber lengths of the inorganic fibers and the synthetic fibers are 6.0 to 0.2 mm, preferably 4.0 to 0.00, in terms of papermaking suitability (formation of a thin film, formation of green board, etc.). It exists in the range of 5 mm, and a fiber diameter exists in the range of 10-50 micrometers. In the case of a synthetic fiber, the fiber diameter is preferably 20 to 50 μm, more preferably 20 to 40 μm.

In addition, calcium silicate hydrate can be produced by mixing a calcareous raw material and a silicic acid raw material with water and hydrothermal synthesis under high temperature and high pressure.
Examples of the calcareous raw material include quick lime and slaked lime, and examples of the siliceous raw material include silica, diatomaceous earth, and silica fume. Silica is particularly preferable.
The synthesis of calcium silicate hydrate can be performed, for example, as follows. The calcareous raw material and the siliceous raw material are mixed at, for example, a mixing ratio (CaO / SiO ₂ molar ratio) of 0.5 to 1.5, preferably 0.5 to 1.2. ~ 20 times, preferably 7-16 times water is added, mixed and dispersed to form a raw material slurry, and the raw material slurry is stirred at a temperature of 150 to 230 ° C, preferably 170 to 210 ° C, Hydrothermal synthesis is performed for 1 to 20 hours, preferably 3 to 12 hours. In this way, calcium silicate hydrate can be obtained as, for example, tobermorite, zonotrite and the like. The average particle diameter of calcium silicate hydrate is in the range of 30 μm to 100 μm, preferably 50 μm to 90 μm.

  The average particle diameter can be adjusted by the particle size of the siliceous raw material, the proportion of water used, the degree of stirring in the pressure vessel, and the like. For example, the particle size of the siliceous raw material is set to 80 μm or less, preferably 60 μm or less, and the amount of water used is 7 to 16 times by mass with respect to the mixture of the calcareous raw material and the siliceous raw material, and is provided in the pressure vessel. The average particle diameter of the obtained calcium silicate hydrate can be adjusted in the range of 30 μm to 100 μm as described above by setting the peripheral speed of the stirring rotary blade to 100 to 200 m / min. In addition, the average particle diameter of the calcium silicate hydrate prescribed | regulated by this specification is calculated | required with the particle size distribution measuring apparatus by the laser diffraction scattering method.

  Wollastonite is also used as an admixture.

  Further, the inorganic filler is not particularly limited as long as it is generally used for an inorganic board, but for example, a filler for improving heat resistance such as mica, fire resistance such as dihydrate gypsum and calcium carbonate. Non-hydratable raw materials such as fillers for improvement and fillers for preventing cracks such as silica can be used. In addition, these can also use 2 or more types together.

  The above-mentioned various raw materials are 30 to 70% by mass, preferably 40 to 60% by mass of a hydratable raw material for matrix formation as a mass ratio with respect to the obtained thin inorganic papermaking plate, (Total amount) 3.5-12% by mass, preferably 3.5-9% by mass, calcium silicate hydrate 5-30% by mass, preferably 8-20% by mass, wollastonite 5-20% by mass, It is preferable to blend so as to be 10 to 20% by mass and 1 to 15% by mass, preferably 3 to 10% by mass of the inorganic filler. The reinforcing fiber has a freeness of 3 to 9% by mass, preferably 3 to 6% by mass and a fiber length of 6.0 to 0.2 mm, and a fiber diameter of 10 to 10%. It is composed of 0.5 to 5% by mass, preferably 0.5 to 3% by mass of inorganic fiber and / or synthetic fiber in the range of ˜50 μm, and the total amount of natural fiber and inorganic fiber and / or synthetic fiber is the above It mix | blends so that it may become in the range.

  Here, when the blending amount of the hydratable raw material for matrix formation is less than 30% by mass, sufficient strength cannot be obtained, and when it exceeds 70% by mass, the apparent density becomes too high, which is not preferable. Further, if the amount of the fiber raw material (total amount of natural fibers and inorganic fibers and / or synthetic fibers) is less than 3.5% by mass, sufficient strength cannot be obtained and the material becomes brittle. If it exceeds mass%, the material becomes softer than necessary and the workability is lowered, which is not preferable. Furthermore, it is not preferable to increase the number of natural fibers or synthetic fibers, which are organic fibers, because the total calorific value exceeds a predetermined value in the exothermic test and a desired nonflammable performance cannot be obtained. In addition, since inorganic fibers are not very dispersible, many of them are difficult to use. If the blending amount of calcium silicate hydrate is less than 5% by mass, it is not preferable because sufficient strength cannot be obtained. If it exceeds 30% by mass, the apparent density of the product is lowered and sufficient strength is obtained. Since it disappears, it is not preferable. Moreover, when the compounding amount of wollastonite is less than 5% by mass, the rate of change in length due to water absorption specified in JIS A 5430 10.7 increases, which is not preferable. Is not preferable because it becomes brittle. Further, if the blending amount of the inorganic filler is less than 1% by mass, it is difficult to form a stable thin film at the time of forming the thin film by the papermaking method, and if it exceeds 15% by mass, sufficient strength can be obtained. It is not preferable because it disappears.

  The manufacturing method of the thin inorganic papermaking board of this invention mix | blends said various materials, Preferably in the said mixture ratio, there are 7-30 times (mass ratio) of various materials, Preferably it is 10-20 times water. Is added and wet-mixed to make a slurry, and the resulting slurry is made into paper to obtain a green plate. After the resulting green plate is dehydrated under pressure, it can be cured by curing.

  In addition, as the papermaking method referred to in this specification, any papermaking method known in the art can be applied, and examples thereof include a round net type papermaking method, a long net type papermaking method, and a flow-on type papermaking method. For example, in the round net making method, the raw slurry is made with a wire mesh cylinder to form a green film (thin film), and the resulting green film is transferred to an endless felt, dehydrated on the endless felt, and applied to a making roll. The green sheet (raw board) is obtained by winding up to a thickness of 1 mm and separating from the making roll when the thickness reaches a predetermined thickness. In addition, the flow-on type papermaking method supplies raw slurry directly onto the endless felt, dehydrates it on the endless felt to form a green film (thin film), winds it up to a predetermined thickness on a making roll, When the thickness is reached, the green sheet (raw board) is obtained by separating from the making roll. Among them, the round net type papermaking method is preferable from the viewpoint that the production efficiency is high, the production of thin objects is possible, and the two-dimensional orientation of the fibers is good, so that the reinforcing performance can be sufficiently exhibited. In the present invention, a sheet-like molded product before pressure dehydration obtained after paper making of a slurry is defined as “green plate”.

The pressure plate can be dehydrated using a pressure dehydration apparatus such as a known press machine. Pressurized dehydration conditions Namaita is holding pressure 16~40N / mm ^2, preferably in the range of 20~40N / mm ^2. Incidentally, when the holding pressure is less than 16N / mm ^2, not preferable since sufficient strength can not be obtained, also when more than 40N / mm ^2, or could not crack occurs and obtain a molded product The molded product obtained is not preferable because it becomes too hard and brittle.

The “apparent density” as used in the present specification means that the obtained material is dried to an absolutely dry state (a state dried at 105 ° C. until reaching a constant weight), and the mass (g) after drying is expressed as its volume (cm can be calculated by the method of dividing the ^3). The apparent density of the inorganic papermaking plate obtained by the production method of the present invention is 1.2 to 1.5 g / cm ³ , preferably 1.3 to 1.5 g / cm ³ . If the apparent density is less than 1.2 g / cm ^3, it is not preferable because sufficient strength cannot be obtained. If the apparent density exceeds 1.5 g / cm ³ , the material becomes hard and the thin inorganic papermaking plate is fixed to the ground. This is not preferable because the workability during the process is reduced.

  The curing and curing method is not particularly limited, and known means such as natural curing, steam curing, and cooling curing can be applied.

  The material thickness of the inorganic building materials currently on the market is 3 to 4 mm, which is a thin material, and the thickness below that is the cause of deflection due to its own weight, resulting in poor handling and handling during construction. Currently. However, the thin inorganic paper-making board produced by the production method of the present invention does not cause deflection due to its own weight even at a thickness of 2 to 5 mm, has good handling properties during transportation and construction, and is easy to work. Have advantages.

  Here, “deflection due to its own weight” is an air-dried plate having a width of 910 mm and a length of 2575 mm (commonly called 8.5-inch size), which is a long type of dimensions generally distributed in the building materials market. Is measured by measuring the difference in height between the support part and the end part in a state where it is hung down by its own weight. It is effective that the height difference is 500 mm or less, preferably 400 mm or less, as the workability in the work. The thin inorganic papermaking plate produced by the production method of the present invention has a small amount of deflection due to its own weight, has good workability, and facilitates work during construction. The “air-dried state” described in the present specification is in accordance with JIS A 5430 10.1 Table 11 and indicates a state of being left for 7 days or more in a well-ventilated room.

  Further, in the thin inorganic papermaking sheet obtained by the production method of the present invention, the maximum deflection in bending pressurization at the time of the bending test was No. 3 test piece defined in JIS A 1408 4.1 (the size of the test specimen is the width). 400 mm, length 500 mm), and the fiber flow direction is the length direction of the No. 3 test piece, and the bending test perpendicular to the length direction, that is, the bending test defined in JIS A 5430 10.3.2 ( When the thickness is 20 to 50 mm in an air-dried state, it can be a substitute characteristic for evaluating the rigidity. The term “maximum deflection” as used herein refers to the elastic region and plasticity of the loaded part until the material breaks in the bending test, that is, the test according to the bisected one-line load method of JIS A 1408 5.1.1. The maximum amount of displacement combined with the area. It should be noted that if the maximum deflection exceeds 50 mm, the thin inorganic papermaking plate becomes too soft and the workability deteriorates, which is not preferable. If the maximum deflection is less than 20 mm, the thin inorganic papermaking plate becomes too hard and brittle. This is not preferable.

In the bending test (the dimensions of the specimen are 400 mm wide, 500 mm long, and the span is 400 mm), the bending strength when the fiber flow direction is the length direction of the specimen is 28 N / it can be mm ² or more. When this bending strength is less than 28 N / mm ² , when the bending due to its own weight occurs, it cannot withstand the bending stress applied to the thin inorganic papermaking plate, and cracks and cracks are generated. However, by satisfying this bending strength, it can withstand bending stress due to deflection due to its own weight, and the workability is remarkably improved.

Moreover, in the manufacturing method of the thin inorganic papermaking board of this invention, 3-6 mass% of natural fibers, 0.5-3 mass% of inorganic fibers and / or synthetic fibers, and the total amount of both is 3.5-9. with the range of weight percent, the total amount of heat generated at the heat generation test at the heating time of 20 minutes with the test device of JIS a 5430 Annex JA defined 4.5MJ / ^{m 2} or less, preferably 3.5MJ / M ² or less. In addition, the measurement of the total calorific value in the present specification is a result obtained by using “Cone Calorimeter III” C3 type (ISO5660 regulation device) manufactured by Toyo Seiki Seisakusho at a radiation amount of 50 kW / m ² .

  A surface decorative layer may be provided on at least one surface of the thin inorganic papermaking plate produced by the method for producing a thin inorganic papermaking plate of the present invention to provide a thin surface inorganic coating paper. By providing the surface decorative layer, the design properties of the thin inorganic papermaking plate can be improved and the added value can be increased. In order to form the surface decorative layer, for example, paint, moisture-permeable paint, plaster paint, decorative paper, moisture-permeable decorative paper, decorative veneer (film), moisture-permeable decorative veneer (film) and the like can be used.

Here, a general urethane paint, an acrylic synthetic resin paint, or the like can be used as the paint.
Moreover, as a moisture-permeable coating material, what is disclosed by the said patent document 2, for example can be used. That is, it is a coating composition containing an alkoxysilane and a synthetic resin dispersion and having a structure having a moisture passage inside the dried coating.
Furthermore, as the plaster paint, a general-purpose product that is widely used at present for a textured outer wall can be used by mixing a slaked lime-based plaster material and a synthetic resin component.
The decorative paper, decorative veneer (film) and the like are not particularly limited as long as various types of coating are generally applied to the paper surface. In addition, when forming a surface decorative layer on the surface of a thin inorganic papermaking board using decorative paper, a decorative veneer (film), etc., it can adhere to the surface of a thin inorganic papermaking board using a conventional adhesive. . As such an adhesive, for example, an epoxy-based adhesive can be used.
Furthermore, as a moisture-permeable decorative paper, a moisture-permeable decorative veneer (film), etc., various coatings are generally applied to the surface of the paper, and the paper and the decorative layer have a large number of pores and are moisture-permeable. If it is a thing, it will not specifically limit. In addition, when forming a surface decorative layer on the surface of a thin inorganic papermaking board using a moisture-permeable decorative paper, a moisture-permeable decorative veneer (film), etc., the surface of the thin inorganic papermaking board using a moisture-permeable adhesive Can be glued to. As such a moisture-permeable adhesive, for example, aqueous vinyl urethane, melamine, vinyl acetate copolymer resin, or the like can be used.

  In addition, when a surface decorative layer is provided on a thin inorganic papermaking board, a sealer layer or a moisture permeable sealer layer is provided between the thin inorganic papermaking board and the surface decorative layer so that the adhesion between the thin inorganic papermaking board and the surface decorative layer is improved. Can be improved. As a sealer for forming the sealer layer, for example, a urethane sealer or the like can be used. Further, the sealer for forming the moisture permeable sealer layer is not particularly limited as long as it has moisture permeability. For example, a silica-modified acrylic copolymer resin, an acrylic resin emulsion, or the like can be used.

Example 1
Calcium silicate hydrate [Tobermorite (slurry, solid content concentration = 10% by mass)] 17% by mass, ordinary Portland cement (manufactured by Taiheiyo Cement Co., Ltd., specific surface area 3300 cm ² / g) having an average particle size of 40 μm; Wollastonite 15% by mass; wood pulp (fiber length 3.5 mm, fiber diameter 30 μm, CSF 280 ml) 6% by mass as natural fiber; polyvinyl alcohol fiber (fiber length 4.0 mm, fiber diameter 27 μm) 2% by mass as synthetic fiber; Water is added to and mixed with a compound having a composition of 10% by weight of calcium carbonate (inorganic filler) to form a slurry having a concentration of about 10% by weight. I got a raw board. The obtained green plate was pressure dehydrated with a press at a pressure of 30 N / mm ² for 10 minutes, then steam-cured at a temperature of 60 ° C. for 15 hours and cured to obtain a 3.2 mm thick inorganic paper plate. Obtained. The physical properties of the resulting inorganic paperboard are as follows:
Apparent density: 1.29 g / cm ³
Deflection by its own weight: 470mm in width 910mm, length 2572mm
Maximum deflection by bending test: 38.2 mm
Bending strength: 28 N / mm ²
Total calorific value: 3.1 MJ / m ²
In addition, the obtained inorganic papermaking plate was not easily bent in the construction, and the screwing to the ground was also good.

Example 2
Calcium silicate hydrate having an average particle size of 40 μm [Tobermorite (slurry, solid content = 10% by mass)] 17% by mass, ordinary Portland cement (manufactured by Taiheiyo Cement Co., Ltd., specific surface area 3300 cm ² / g) 50% by mass; Wollastonite 20% by mass; wood pulp (fiber length 3.5 mm, fiber diameter 30 μm, CSF 280 ml) 6% by mass as natural fiber; polyvinyl alcohol fiber (fiber length 4.0 mm, fiber diameter 27 μm) 2% by mass as synthetic fiber; Water is added to and mixed with a compound having 5% by mass of calcium carbonate (inorganic filler) to form a slurry having a concentration of about 10% by mass. I got a raw board. The obtained green plate was subjected to pressure dehydration with a press at a pressure of 38 N / mm ² for 10 minutes, then steam-cured at a temperature of 60 ° C. for 15 hours and cured to obtain an inorganic paper-making plate having a thickness of 3.2 mm. Obtained. The physical properties of the resulting inorganic paperboard are as follows:
Apparent density: 1.32 g / cm ³
Deflection by its own weight: 470mm in width 910mm, length 2572mm
Maximum deflection by bending test: 35.5mm
Bending strength: 28 N / mm ²
Total calorific value: 3.3 MJ / m ²
In addition, the obtained inorganic papermaking plate was not easily bent in the construction, and the screwing to the ground was also good.

Example 3
Calcium silicate hydrate having an average particle size of 40 μm [tobermorite (slurry, solid content = 10% by mass)] 15% by mass, ordinary Portland cement (manufactured by Taiheiyo Cement Co., Ltd., specific surface area 3300 cm ² / g) 55% by mass; Wollastonite 15% by mass; wood pulp (fiber length 3.5 mm, fiber diameter 30 μm, CSF 280 ml) 6% by mass as natural fiber; polyvinyl alcohol fiber (fiber length 4.0 mm, fiber diameter 27 μm) 2% by mass as synthetic fiber; Water is added to and mixed with a compound having a composition of 7% by mass of calcium carbonate (inorganic filler) to form a slurry having a concentration of about 10% by mass. I got a raw board. The obtained green plate was subjected to pressure dehydration with a press at a pressure of 32 N / mm ² for 10 minutes, and then steam-cured at a temperature of 60 ° C. for 15 hours and cured to obtain a 3.2 mm thick inorganic paper plate. Obtained. The physical properties of the resulting inorganic paperboard are as follows:
Apparent density: 1.36 g / cm ³
Deflection by its own weight: 470mm in width 910mm, length 2572mm
Maximum deflection by bending test: 30.6 mm
Bending strength: 31 N / mm ²
Total calorific value: 2.9 MJ / m ²
In addition, the obtained inorganic paper-making board was not easily bent in the construction, and the screwing to the base was also good.

Example 4
Calcium silicate hydrate with an average particle size of 40 μm [tobermorite (slurry, solid content = 10% by mass)] 15% by mass, ordinary Portland cement (manufactured by Taiheiyo Cement, specific surface area 3300 cm ² / g) 50% by mass; Wollastonite 15% by mass; wood pulp (fiber length 3.5 mm, fiber diameter 30 μm, CSF 280 ml) 6% by mass as natural fiber; polyvinyl alcohol fiber (fiber length 4.0 mm, fiber diameter 27 μm) 2% by mass as synthetic fiber; Water is added to and mixed with a compound having a composition of 7% by mass of calcium carbonate (inorganic filler) to form a slurry having a concentration of about 10% by mass. I got a raw board. The obtained raw plate was pressurized圧脱water over 10 minutes at a pressure of 30 N / mm ² by a press machine, and 15 hours steam aging at a temperature 60 ° C., the inorganic papermaking plate having a thickness of 3.2mm by curing Obtained. The physical properties of the resulting inorganic paperboard are as follows:
Apparent density: 1.27 g / cm ³
Deflection by its own weight: 470mm in width 910mm, length 2572mm
Maximum deflection by bending test: 38.1 mm
Bending strength: 30 N / mm ²
Total calorific value: 4.5 MJ / m ²
In addition, since the total amount of wood pulp and polyvinyl alcohol fiber is as large as 11% by mass, the obtained inorganic paperboard has a high total calorific value, but it is easy to bend in construction and is screwed to the base. It was good.

Example 5
Calcium silicate hydrate with an average particle size of 40 μm [tobermorite (slurry, solid content = 10% by mass)] 15% by mass, ordinary Portland cement (manufactured by Taiheiyo Cement Co., Ltd., specific surface area 3300 cm ² / g) 55% by mass; Wollastonite 15% by mass; wood pulp as natural fiber (fiber length 3.5 mm, fiber diameter 30 μm, CSF 280 ml) 6% by mass; alkali-resistant glass fiber (ARG: fiber length 4.0 mm, fiber diameter 13 μm) 2 as inorganic fiber 2 Mass%: Calcium carbonate (inorganic filler) 7% by mass of a mixture, water is added and mixed to make a slurry with a concentration of about 10% by mass. A green board having a predetermined thickness was obtained. The obtained raw plate was pressurized圧脱water over 10 minutes at a pressure of 32N / mm ² by a press machine, and 15 hours steam aging at a temperature 60 ° C., the inorganic papermaking plate having a thickness of 3.2mm by curing Obtained. The physical properties of the resulting inorganic paperboard are as follows:
Apparent density: 1.34 g / cm ³
Deflection due to its own weight: 910mm in width 910mm, length 2572mm, 460mm
Maximum deflection by bending test: 27.5mm
Bending strength: 28 N / mm ²
Total calorific value: 2.8 MJ / m ²
In addition, the obtained inorganic paper-making board was not easily bent in the construction, and the screwing to the base was also good.

Comparative Example 1
Calcium silicate hydrate having an average particle size of 40 μm [Tobermorite (slurry, solid content = 10% by mass)] 17% by mass, ordinary Portland cement (manufactured by Taiheiyo Cement Co., Ltd., specific surface area 3300 cm ² / g) 50% by mass; Wollastonite 15% by mass; wood pulp (fiber length 3.5 mm, fiber diameter 30 μm, CSF 280 ml) 6% by mass as natural fiber; polyvinyl alcohol fiber (fiber length 4.0 mm, fiber diameter 27 μm) 2% by mass as synthetic fiber; Water is added to and mixed with a compound having a composition of 10% by mass of calcium carbonate (inorganic filler) to form a slurry having a concentration of about 10% by mass. I got a raw board. The obtained green plate was subjected to pressure dehydration for 10 minutes at a pressure of 15 N / mm ² with a press machine, then steam-cured at a temperature of 60 ° C. for 15 hours, and cured to form an inorganic paper sheet having a thickness of 3.3 mm. Obtained. The physical properties of the resulting inorganic paperboard are as follows:
Apparent density: 1.15 g / cm ³
Deflection due to its own weight: 610mm in width 910mm, length 2572mm
Maximum deflection by bending test: 51.2mm
Bending strength: 21 N / mm ²
In addition, the obtained inorganic papermaking board had a big deflection | deviation and was a thing which was hard to construct.

Comparative Example 2
Calcium silicate hydrate [Tobermorite (slurry, solid content concentration = 10% by mass)] 17% by mass, ordinary Portland cement (manufactured by Taiheiyo Cement Co., Ltd., specific surface area 3300 cm ² / g) having an average particle size of 40 μm; Wollastonite 5 mass%; wood pulp (fiber length 3.5 mm, fiber diameter 30 μm, CSF 280 ml) 6 mass% as natural fiber; polyvinyl alcohol fiber (fiber length 4.0 mm, fiber diameter 27 μm) 2 mass% as synthetic fiber; Water is added to and mixed with a compound having a composition of 20% by mass of calcium carbonate (inorganic filler) to form a slurry having a concentration of about 10% by mass. I got a raw board. The obtained green plate was subjected to pressure dehydration with a press at a pressure of 9 N / mm ² for 10 minutes, then steam-cured at a temperature of 60 ° C. for 15 hours and cured to obtain a 3.2 mm thick inorganic papermaking plate. Obtained. The physical properties of the resulting inorganic paperboard are as follows:
Apparent density: 0.91 g / cm ³
Deflection due to its own weight: 730mm in width 910mm, length 2572mm
Maximum deflection by bending test: 58.2mm
Bending strength: 18 N / mm ²
In addition, the obtained inorganic papermaking board had a big deflection | deviation and was a thing which was hard to construct.

Comparative Example 3
Calcium silicate hydrate having an average particle size of 40 μm [Tobermorite (slurry, solid content = 10% by mass)] 17% by mass, ordinary Portland cement (manufactured by Taiheiyo Cement Co., Ltd., specific surface area 3300 cm ² / g) 50% by mass; Wollastonite 20% by mass; wood pulp (fiber length 3.5 mm, fiber diameter 30 μm, CSF 280 ml) 6% by mass as natural fiber; polyvinyl alcohol fiber (fiber length 4.0 mm, fiber diameter 27 μm) 2% by mass as synthetic fiber; Water is added to and mixed with a compound having 5% by mass of calcium carbonate (inorganic filler) to form a slurry having a concentration of about 10% by mass. I got a raw board. The obtained green plate was subjected to pressure dehydration for 10 minutes at a pressure of 15 N / mm ² with a press machine, and then steam-cured at a temperature of 60 ° C. for 15 hours and cured to obtain an inorganic papermaking plate having a thickness of 3.2 mm. Obtained. The physical properties of the resulting inorganic paperboard are as follows:
Apparent density: 1.08 g / cm ³
Deflection due to its own weight: 730mm in width 910mm, length 2572mm
Maximum deflection by bending test: 55.7 mm
Bending strength in the fiber direction: 18 N / mm ²
In addition, the obtained inorganic papermaking board had a too big deflection | deviation and was a thing which was hard to construct.

Comparative Example 4
Calcium silicate hydrate having an average particle size of 40 μm [Tobermorite (slurry, solid content = 10% by mass)] 17% by mass, ordinary Portland cement (manufactured by Taiheiyo Cement Co., Ltd., specific surface area 3300 cm ² / g) 50% by mass; Wollastonite 15% by mass; wood pulp (fiber length 3.5 mm, fiber diameter 30 μm, CSF 280 ml) 6% by mass as natural fiber; polyvinyl alcohol fiber (fiber length 4.0 mm, fiber diameter 27 μm) 2% by mass as synthetic fiber; Water is added to and mixed with a compound having a composition of 10% by weight of calcium carbonate (inorganic filler) to form a slurry having a concentration of about 10% by weight. I got a raw board. When the obtained green plate was pressure dehydrated with a press at a pressure of 48 N / mm ² , cracks occurred and a good test specimen could not be produced.

  The thin inorganic papermaking board obtained by the production method of the present invention can be suitably used as a building material or the like.

Claims (3)

30 to 70% by mass of a hydratable raw material for forming a matrix; 3 to 9% by mass of natural fibers having a freeness within the range of 150 to 450 ml in Canadian standard freeness, a fiber length of 6.0 to 0.2 mm, and a fiber diameter of 10 to 10%. 0.5 to 5% by mass of inorganic fiber and / or synthetic fiber (excluding asbestos) in the range of 50 μm, provided that the total amount of natural fiber and inorganic fiber and / or synthetic fiber is 3.5 to 12% by mass; Calcium silicate hydrate having an average particle diameter of 30 to 100 μm obtained by hydrothermal synthesis of raw materials and siliceous raw materials 5 to 30% by mass; wollastonite 5 to 20% by mass; and inorganic filling A mixture containing 1 to 15% by mass of the material is wet-mixed to obtain a slurry, and the resulting slurry is made into paper to obtain a green plate. The green plate is held at a pressure of 16 to 40 N during pressure dehydration. / After pressurizing圧脱water m ^{2, and} the thickness of 2 to 5 mm, a manufacturing method of thin inorganic papermaking plate, characterized in that to obtain a cured product of an apparent density 1.2~1.5g / cm ³ by curing curing. Deflection due to its own weight when it is supported at the center in the length direction of the thin inorganic papermaking sheet in the length direction having a width of 910 mm and a length of 2575 mm is 500 mm or less due to the difference between the center and the edge. Yes, using the No. 3 test piece specified in JIS A 1408 4.1, the maximum deflection by the bending test based on JIS A 5430 10.3.2, and the bending strength is 28 N / mm ² or more The manufacturing method of the thin inorganic papermaking board of Claim 1 which is. 3 to 6% by mass of natural fiber and 0.5 to 3% by mass of inorganic fiber and / or synthetic fiber, provided that the total amount of natural fiber and inorganic and / or synthetic fiber is in the range of 3.5 to 9% by mass The total calorific value in the exothermic test in a heating time of 20 minutes using a test apparatus defined in JIS A 5430 Annex JA of a thin inorganic papermaking board is 4.5 MJ / m ² or less. The manufacturing method of the thin inorganic papermaking board of description.