JP2003212629A - Inorganic material board and its manufacturing method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an inorganic material board which is noninflammable and has excellent durability, into which a nail or the like is driven easily and which has strong drawing-out resistance equal to that of plywood when the driven nail is drawn out and to provide a method for manufacturing the inorganic material board. <P>SOLUTION: This inorganic material board is obtained by wet-forming a blend of 15 to 50 mass% lightweight calcium silicate-based hydrate having 0.05 to 0.3 bulk density, 6 to 15 mass% reinforcing fiber, 10 to 60 mass% cement and 0 to 60 mass% filler. The reinforcing fiber consists of a natural fiber and a synthetic fiber of 6:1 to 2:1 mass ratio. This inorganic material board contains ≥2 mass% synthetic fiber having ≥5 kN/mm<SP>2</SP>Young's modulus. This inorganic material board is obtained by wet-forming the blend to obtain a green sheet, pressing one green sheet or several stacked green sheets under press pressure of 1 to 20 N/mm<SP>2</SP>and subsequently aging/hardening the pressed green sheet. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an inorganic plate and a method for producing the same, and more specifically, it is nonflammable and has excellent durability, and nails, screws, staples, etc. (hereinafter simply referred to as nails). The present invention relates to an inorganic plate that is easy to hit, and has a strong pull-out resistance to a nail that has been hit, which is equivalent to a wooden plywood, and a method for manufacturing the inorganic plate.

[0002]

2. Description of the Related Art Wooden plywood is easy to hit with nails, etc.
Since it has a strong pull-out resistance against nails that have been struck, it has excellent strength and flexibility, and it is simple and inexpensive,
It is widely used in various fields in the fields of architecture and civil engineering. For example, a formwork material such as concrete is produced by pasting wood serving as a pillar and a wooden plywood, but it is necessary to drive a nail or the like from the pillar side to penetrate the wooden plywood and fix it. At this time, since the wood plywood itself has a strong pulling resistance, it is often used for such formwork materials. However, generally used wood plywood is flammable, corrosive and erosive by insects, and it is hard to say that it has excellent durability. In addition, environmental damage due to deforestation and problems in the living environment due to adhesives have been pointed out.

On the other hand, most of the inorganic boards such as flexible boards and calcium silicate boards have noncombustibility and durability, but have the drawback of being hard and brittle. There is also a drawback that they can easily be pulled out or cracks or breaks occur.
Heretofore, there has been no inorganic board that has a stronger pull-out resistance and is easier to hit with nails and the like than wooden plywood.

Further, as an inorganic plate which is nonflammable, excellent in durability, high in nail holding power and small in rate of change in length, 20 to 60% by mass of cement is prepared by hydrating and synthesizing a calcareous raw material and a siliceous raw material in advance. Calcium silicate-based lightweight hydrothermal compound 5-5
There has been proposed an inorganic load bearing surface material obtained by wet-molding a compound consisting of 0% by mass, 3 to 18% by mass of reinforcing fibers and 0 to 60% by mass of a filler (JP-A-2001-48630). However, although such an inorganic board has good properties as a bearing surface material, the nail pulling resistance of the board itself in a portion where there is no pillar material on the back surface is insufficient.

[0005]

SUMMARY OF THE INVENTION Therefore, an object of the present invention is that it is non-combustible and has excellent durability, it is easy to hit nails, etc., and that it has a strong pull-out resistance against nails hit, which is equivalent to wood plywood. An object is to provide a certain inorganic plate and a method for manufacturing the inorganic plate.

[0006]

The present invention has a bulk density of 0.
05-0.3 calcium silicate-based lightweight hydrate 15-50 mass%,
Reinforcing fibers 6 to 15 mass%, cement 10 to 60 mass% and an inorganic plate obtained by wet molding a mixture consisting of 0 to 60 mass%, the reinforcing fibers consist of natural fibers and synthetic fibers, The mass ratio of the two is 6: 1 as the former: the latter.
~ 2: 1 and 2% by mass or more of synthetic fiber with Young's modulus of 5 kN / mm ² or more, nail pull-out resistance value of 5 N / mm or more, and nail press-fit value of 30 N / mm to 150 N / mm The present invention provides an inorganic plate characterized by The present invention also provides that the cement comprises one or more selected from ordinary Portland cement, early strength Portland cement and ultra-early strength Portland cement, and has a mortar compression strength of 28 days according to JIS R 5201. The above-mentioned inorganic plate is characterized by having a surface area of 30 N / mm ² or more. Further, the present invention has a bulk density of 0.
05-0.3 calcium silicate-based lightweight hydrate 15-50 mass%,
6-15 mass% of reinforcing fibers, 10-60 mass% of cement, and 0-60 mass% of filler are wet-molded to obtain a green sheet, and one or more of the green sheets are laminated, The present invention provides a method for producing an inorganic plate, which comprises press-forming with a press pressure of 1 to ²⁰ N / mm ² , followed by curing and curing.

The inorganic load bearing surface material disclosed in Japanese Patent Laid-Open No. 2001-48630 has 3 to 15% by mass of pulp as reinforcing fibers, 0 to 2% by mass of fibers having Young's modulus of 5 kN / mm ² or more, and Young's modulus of 5 kN. / mm and comprise a 0-2 wt% fibers of less than ^2, the inorganic board comprising a Young's modulus 5 kN / mm ² or more synthetic fibers in the present invention than 2 wt% does not disclose any.

[0008]

BEST MODE FOR CARRYING OUT THE INVENTION The present invention will be described in more detail below. The inorganic plate in the present invention is made of calcium silicate-based lightweight hydrate, reinforcing fibers, cement and, if necessary, a filler.

The calcium silicate-based lightweight hydrate can be prepared by a known method using a calcareous raw material and a siliceous raw material. For example, the calcium silicate-based lightweight hydrate of the present invention has a molar ratio of calcium oxide to silica of 0.
This can be obtained by preparing a slurry having a concentration of 6 to 15% of 55 to 1.10. And hydrothermally synthesizing the slurry in a stirring autoclave at 150 to 230 ° C. Silica as a siliceous raw material,
Examples of calcareous raw materials such as diatomaceous earth and silica fume include quick lime and slaked lime. The calcium silicate-based lightweight hydrate in the present invention can be a tobermorite-based and / or xonotlite-based, etc., and has a bulk density of 0.05 to 0.
3, preferably 0.05 to 0.2. Here, if the bulk density of the calcium silicate-based lightweight hydrate is less than 0.05, the required nail pullout resistance value is less than 5 N / mm, and sufficient nail pullout resistance cannot be obtained. On the other hand, if it exceeds 0.3, the nail press-fit value is 150.
It exceeds N / mm and nails etc. cannot be driven easily.
The bulk density of the calcium silicate-based lightweight hydrate referred to in the present invention means that the slurry of the calcium silicate-based lightweight hydrate is filtered and dehydrated with a Buchner funnel or the like, and the volume (I) of the wet filter cake is measured, The mass (II) of the filter cake after drying is measured, and the dry mass per unit wet volume of the calcium silicate-based lightweight hydrate calculated by the formula II ÷ I is meant. It is used as an index to evaluate the properties of calcium hydrate.

The calcium silicate-based lightweight hydrate is blended in the raw material of the inorganic plate in the range of 15 to 50% by mass. 15% by mass
If it is less than the above, it is not possible to sufficiently reduce the weight of the inorganic plate, the plate becomes stiff, the nail press-in value exceeds 150 N / mm, and nails cannot be easily hammered in, and the nail pull-out resistance value is less than 5 N / mm, which is sufficient. No nail pulling resistance can be obtained. On the other hand, if it exceeds 50% by mass, it is necessary to press-form at high pressure in order to obtain necessary bulk density and sufficient strength, resulting in a nail press-fit value of 150 N / It becomes over mm, and nails etc. cannot be driven in easily.

The nail pullout resistance value referred to in the present invention is JI
It is a value determined according to SZ 2101 "Testing method for wood".
A good nail pull-out resistance value is empirically 5 N / mm or more. The nail press-fit value is a value obtained by dividing the maximum load value, which is required to drive the N32 nail vertically into the inorganic plate at a constant speed, by the plate thickness. A good nail press-in value (nailability) is empirically 30 N / mm
Above 150 N / mm.

The reinforcing fiber used in the present invention is composed of natural fiber and synthetic fiber, and the mass ratio of the both is 6: 1 to 2: 1 as the former: the latter, and the Young's modulus is 5 kN / mm ² or more. It contains 2% by mass or more of fibers. Examples of the natural fibers include plant fibers such as wood pulp, recycled pulp and various hemp fibers, and one or more of these can be used. Examples of the synthetic fiber include polyvinyl alcohol, polypropylene, polyethylene, polyester, acrylic, rayon, glass wool, rock wool, ceramics wool, carbon fiber and the like, and one or more of these can be used. The compounding ratio of the natural fiber and the synthetic fiber in the reinforcing fiber is as follows:
It is 6: 1 to 2: 1 (mass ratio), preferably 4: 1 to 3: 1. If the proportion of the synthetic fibers is less than the above range, peeling, cracking, or cracking of the back surface of the inorganic plate is likely to occur when nails are hammered in, impact resistance decreases, and the nail pull-out resistance value is 5 N /
Since it is less than mm, sufficient nail pulling force cannot be obtained. On the other hand, when the ratio of the natural fibers is small, the amount of the powder adhered to the natural fibers cannot be sufficiently obtained, and it is difficult to obtain a good inorganic plate. In addition,
As described above, the reinforcing fiber needs to contain 2% by mass or more, preferably 2.0 to 3.0% by mass, of a synthetic fiber having a Young's modulus of 5 kN / mm ² or more. By compounding the synthetic fibers in this way, the nail pulling resistance and strength of the inorganic plate are significantly improved. If the synthetic fiber having a Young's modulus of 5 kN / mm ² or more is less than 2% by mass, the impact resistance decreases and the nail pull-out resistance value is 5 N / mm.
It becomes less than the value, and sufficient nail pulling resistance cannot be obtained. Also,
The fiber length of the reinforcing fibers is 3-12 mm, preferably 3-6 mm
Is. The fiber diameter is 10 to 500 μm, preferably 10
~ 100 μm.

The reinforcing fiber is mixed in the raw material of the inorganic plate in the range of 6 to 15% by mass. If it is less than 6% by mass, a sufficient amount of powder adhered to the natural fibers cannot be obtained, and it is difficult to obtain a good inorganic plate. Also, when nails etc. are hammered in, the back surface of the inorganic plate is peeled off, cracked or cracked. Is likely to occur. Furthermore, because the impact resistance of the inorganic plate is reduced, the nail pull-out resistance value is 5 N / mm
It becomes less than the value, and sufficient nail pulling resistance cannot be obtained. Conversely 15
When the content is more than mass%, sufficient fluidity cannot be obtained when the compound is wet-molded, so that it is difficult to manufacture and it is difficult to obtain a good inorganic plate. In addition, the change in length becomes large, and the incombustibility characteristic of the inorganic plate cannot be obtained.

The cement used in the present invention is not particularly limited, but one that exhibits strength in a short period of time is preferable. For example, JIS R 5201 “Cement physical testing method”
It is preferable to use one or more of ordinary Portland cement, early strength Portland cement and ultra-early strength Portland cement having a compressive strength of mortar on the 28th of 30 N / mm ² or more. If such cement is used, the curing time can be shortened and sufficient nail pullout resistance can be obtained.

Cement is mixed in the raw material of the inorganic plate in the range of 10 to 60% by mass. If the amount of cement is less than 10% by mass, the strength required for bonding cannot be sufficiently obtained, and the nail pullout resistance value becomes less than 5 N / mm, so that sufficient nail pullout resistance cannot be obtained. If it exceeds 60% by mass, the inorganic plate becomes hard and brittle, and the nail press-fit value exceeds 150 N / mm, so that nails and the like cannot be easily driven. In addition, the back surface of the inorganic plate or the entire plate may be cracked.

In the present invention, various fillers can be used if necessary. As the filler, coal ash, silica fume, slag powder, shirasu, silica stone powder, etc. that contribute to pozzolanic activity and contribute to strength, mica powder, wollastonite powder, calcium carbonate, talc, length change of inorganic plates such as bentonite Those which contribute to physical properties such as rate and manufacturability are mentioned. The filler is mixed in the raw material of the inorganic plate in the range of 0 to 60% by mass. If the filler exceeds 60% by mass, the amount of other compounds added will be small and the nail pull-out resistance will be 5 N / mm.
It becomes less than the value, and sufficient nail pulling resistance cannot be obtained.

In the inorganic plate of the present invention, a mixture (slurry) is prepared by mixing the above-mentioned raw materials in the mixing ratio thereof, the mixture is wet-molded to obtain a green sheet, and one or a plurality of the green sheets are prepared. It can be obtained by stacking the sheets, press-molding them with a press pressure of 1 to ²⁰ N / mm ² , and subsequently curing and curing. For wet molding, a general-purpose manufacturing device such as a round-net paper making machine, a fourdrinier paper making machine, a continuous paper making machine such as a flow-on paper making machine, or a batch molding machine such as a dewatering press can be used. Next, one or more green sheets obtained are laminated and pressure-molded. If the press pressure at this time is less than 1 N / mm ² , the required strength, surface smoothness, and sufficient nail pull-out resistance are obtained. I can't get it. On the other hand, if it exceeds 20 N / mm ² , the weight cannot be reduced, and the nail press-fit value exceeds 150 N / mm, and it is difficult to drive nails and the like. The density of the inorganic plate after pressure molding varies depending on the blending ratio of the raw materials and the pressing pressure, but is preferably 0.6 to 1.2 g / cm ³ . Examples of the curing of the inorganic plate include natural curing, wet curing, steam curing, autoclave curing and the like, but steam curing is preferable in order to shorten the curing time and obtain sufficient nail pullout resistance.

The inorganic plate of the present invention thus obtained has a nail pull-out resistance value of 5 N / mm or more and a nail press-fit value of 30 N / mm to 150 N / mm. Therefore, nails and the like can be easily hammered, and the nails and the like that have been hammered have a strong pull-out resistance equivalent to that of wood plywood. Furthermore, it is nonflammable and has excellent durability.

[0019]

EXAMPLES The present invention will be further described below with reference to Examples and Comparative Examples. The raw materials used in Examples 1 to 8 and Comparative Examples 1 to 9 are as follows. Calcium silicate-based lightweight hydrate: Powder silica and quicklime are used as raw materials, and calcium oxide / silica molar ratio is 0.83, 1
Hydrothermal synthesis was carried out with a stirring autoclave at a slurry concentration of 0%. (1) Tobermorite (Tb 180 ° C for 3 hours hydrothermal synthesis, bulk density 0.13) (2) Xonotorite (Xn 195 ° C for 4 hours hydrothermal synthesis, bulk density 0.15) Reinforcing fiber: wood pulp (Carter Holt Harvey,
Tasman H-90); Polyvinyl alcohol (PVA) fiber (average length 4 mm, aspect ratio 290, Young's modulus 41.1
kN / mm ² ); Polyester fiber (average length 4 mm,
Aspect ratio 200, Young's modulus 3.1kN / mm ² ) Cement: Normal Portland cement (JIS R 52
The mortar compressive strength of No. 01 on the 28th is 45N / mm ² );
Early strength Portland cement (JIS R 5201 mortar compressive strength of 28 days is 50N / mm ² ) Filler: calcium carbonate; wollastonite powder (Wollastonite)

A mixture was prepared by mixing the above raw materials with the mixture ratios shown in Tables 1 and 2, and 9 times the amount of water was added to form a slurry. The slurry was wet-molded by a flow-on paper machine to obtain a slurry. The single-layer green sheet thus obtained was pressure-molded under the press pressures shown in Tables 1 and 2 to obtain a single-layer plate having a thickness of about 10 mm. This plate was steam-cured and then naturally cured to be a test piece. After drying the test piece, the following test was performed.

Test method The density test was carried out according to the test method of the apparent density (section 6.3) of JIS A 5430 "Fiber reinforced cement board". The nail pull-out resistance value was measured according to JIS Z 2101. The nail press-in value is the maximum load that is required to penetrate the plate by driving N32 nail vertically into the plate whose plate thickness was measured in advance at a constant speed of 8 mm / min using the autograph manufactured by Shimadzu Corporation. The value was divided by the plate thickness. The nailability was evaluated by touching the inorganic plate with a hammer and then evaluating the workability. Good: The nail is satisfactorily embedded in the board by hitting the nail several times. Bad: The board is too hard to hit the nails. It causes cracking and damage. The board is too soft to get the nailing effect. The bending strength test was measured according to the test method of the bending strength test (section 6.4) of JIS A 5430 "fiber reinforced cement plate". The obtained results are shown in Table 1 and Table 2, respectively.

[0022]

[Table 1]

From the results shown in Table 1, the inorganic plates obtained by the blends of Examples 1 to 8 have a nail pull-out resistance value of 5 N / mm or more, which has a sufficient nail pull-out resistance and a nail press-fit value. 30N
/ Mm or more and 150N / mm or less, it can be seen that nails can be easily driven in.

[0024]

[Table 2]

From the results in Table 2: In Comparative Example 1, since the cement content was large, the inorganic plate became hard and the nail press-in value was high, and nailing could not be easily performed. In Comparative Example 2, since the cement content was small, the inorganic plate became brittle, cracks or peeling of the back surface occurred, the nail pullout resistance value became low, and sufficient nail pullout resistance could not be obtained. Comparative Example 3
Due to the large amount of fibers, it was difficult to make paper during manufacturing, and a good inorganic plate could not be obtained. In Comparative Example 4, since the amount of fiber was small, it was difficult to make a paper during manufacturing, and a good inorganic plate could not be obtained. In Comparative Example 5, since there were few synthetic fibers having a Young's modulus of 5 kN / mm ² or more, the nail pullout resistance value was low, and sufficient nail pullout resistance could not be obtained. Especially this comparative example
Comparing 5 with Example 8 described above, although both examples have almost the same composition, Example 8 has a good nail pull-out resistance because the synthetic fiber having a Young's modulus of 5 kN / mm ² or more is 2% by mass or more. In contrast to Comparative Example 5, these properties are poorer than those of Example 8 while providing nailing properties. Comparative Example 6
Since the calcium silicate-based lightweight hydrate content was large, the inorganic plate became stiff, and the nail press-in value was high, making nailing difficult. In Comparative Example 7, since the calcium silicate-based lightweight hydrate content was small, the inorganic plate became stiff, and the plate was cracked by hitting a nail, so that evaluation could not be performed. In Comparative Example 8, since synthetic fibers were not included in the fibers, peeling of the back surface occurred by hitting a nail, the nail pullout resistance value was low, and sufficient nail pullout resistance was not obtained. Comparative example
In No. 9, since the amount of natural fibers in the fibers was small, the amount of the powder adhered to the fibers was not sufficiently obtained, and a good plate could not be obtained.

Reference Examples 1 and 2 are also shown in Table 2. Reference Example 1 is an example using a commercially available asbestos-free calcium silicate board having a bulk density of 0.8 and a thickness of 8 mm. It can be seen that this conventional inorganic plate has poor nail pullout resistance. Reference Example 2 is an example using a commercially available structural plywood having a thickness of 9 mm. Since the plywood of Reference Example 2 is a wooden plywood, it has nail pull-out resistance and nail press-fitting properties.

[0027]

EFFECTS OF THE INVENTION According to the present invention, an inorganic plate and an inorganic material which are nonflammable and have excellent durability, are easy to hit nails, and have a strong pull-out resistance against the nails that have been hit, similar to those of wood plywood. A method of making a plate is provided. The inorganic board of the present invention has excellent nailing performance and high nail pull-out resistance, and is sufficiently suitable for those that conventionally used wood-based plywood such as formwork materials such as concrete, which are strongly required to have this property. It can be replaced.

─────────────────────────────────────────────────── ─── Continuation of front page (51) Int.Cl. ⁷ Identification code FI theme code (reference) // C04B 111: 30 B28B 11/00 Z (72) Inventor, Yoshikatsu Harada 3464 Matsubara, Akeno-cho, Makabe-gun, Ibaraki No. F term (reference) 4G012 PA03 PA22 PA24 PC11 4G052 GA02 GA11 GA14 GA17 GB53 GC03 GC06 4G055 AA02 AC09 BA22

Claims (3)

[Claims] 1. A blend comprising 15 to 50% by mass of a calcium silicate lightweight hydrate having a bulk density of 0.05 to 0.3, 6 to 15% by mass of reinforcing fibers, 10 to 60% by mass of cement, and 0 to 60% by mass of a filler. In an inorganic plate obtained by wet-molding a product, the reinforcing fibers are composed of natural fibers and synthetic fibers, the mass ratio of the former is the latter: 6: 1 to 2: 1 and the Young's modulus is 5 kN / mm. Containing 2% by mass or more of ² or more synthetic fibers, nail pull-out resistance value is 5 N / mm or more, and nail press-fit value is 30
An inorganic plate characterized by being N / mm to 150 N / mm. 2. The cement comprises one or more selected from ordinary Portland cement, early strength Portland cement and ultra early strength Portland cement, and its mortar compressive strength of 28 days according to JIS R 5201. ^2. The inorganic plate according to claim 1, which has a surface area of 30 N / mm ² or more. 3. A composition comprising 15 to 50% by mass of a calcium silicate-based lightweight hydrate having a bulk density of 0.05 to 0.3, 6 to 15% by mass of reinforcing fibers, 10 to 60% by mass of cement, and 0 to 60% by mass of a filler. 1 to 20 N / mm ² by subjecting the product to wet molding to obtain a green sheet, and laminating one or a plurality of the green sheets.
A method for producing an inorganic plate, which comprises press-molding with a press pressure, followed by curing and curing.