JPWO2019087625A1 - Gypsum-containing board and method for manufacturing gypsum-containing board - Google Patents

Abstract

A gypsum-containing plate containing a gypsum core, wherein the gypsum core contains a magnetic material and gypsum, and the gypsum core is thickened from one surface side to the other surface side along the thickness direction. When the three regions of the same first end region, central region, and second end region are set, the content of the magnetic material in the first end region is the magnetic content of the central region. Provided is a gypsum-containing plate having a content higher than that of the material.

Description

The present invention relates to a gypsum-containing plate and a method for producing the gypsum-containing plate.

Conventionally, there has been a need to fix printed matter or the like on a wall or the like with a magnetic material such as a magnet in, for example, a school building or a commercial facility. Therefore, as a building material used when forming a wall or the like, a building material capable of attracting a magnet has been required.

Therefore, for example, a method of attaching an iron plate to the surface of a wall base material or applying a paint containing iron powder has been conventionally used.

For example, Patent Document 1 discloses a bulletin board wall in which a thin iron plate is interposed between a wallpaper and a base material so that an article can be held by utilizing the attractive force of a magnet.

Japan Kunizane Kaihei 6-78983 Gazette

However, according to the method of attaching an iron plate to the base material or applying a paint containing iron powder, it is not suitable for base finishing. Further, when finishing the surface of an iron plate or the like with wallpaper or the like, it may be necessary to perform a pretreatment in consideration of compatibility between the iron plate or the paint and the finishing material.

In addition, performing construction such as attaching an iron plate to the surface of the base material at the site is also a problem in that the number of man-hours increases.

Therefore, there has been a demand for a base material capable of attracting a magnet without performing a process such as attaching an iron plate to the surface.

In view of the above problems of the prior art, one aspect of the present invention is to provide a gypsum-containing plate capable of attracting a magnet.

In order to solve the above problems, according to one embodiment of the present invention, a gypsum-containing plate containing a gypsum core.
The gypsum core contains a magnetic material and gypsum.
The gypsum core is formed along the thickness direction from one surface side to the other surface side with three regions having the same thickness: a first end region, a central region, and a second end region. If you do
Provided is a gypsum-containing plate in which the content of the magnetic material in the first end region is higher than the content of the magnetic material in the central region.

According to one embodiment of the present invention, it is possible to provide a gypsum-containing plate capable of attracting a magnet.

The perspective view of the gypsum core of the gypsum-containing plate which concerns on embodiment of this invention. The explanatory view of the magnet adsorption test of the gypsum-containing plate which concerns on embodiment of this invention. The explanatory view of the manufacturing method of the gypsum-containing board which concerns on embodiment of this invention. It is explanatory drawing of the evaluation method of the attraction force to the pair 1mm iron plate of the magnet used in Experimental Example 4-1 to Experimental Example 4-7.

Hereinafter, embodiments for carrying out the present invention will be described with reference to the drawings, but the present invention is not limited to the following embodiments and does not deviate from the scope of the present invention. Can be modified and substituted in various ways.
[Gypsum-containing board]
An example of the configuration of the gypsum-containing plate of the present embodiment will be described.

The gypsum-containing plate of the present embodiment is a gypsum-containing plate containing a gypsum core, and the gypsum core can contain a magnetic material and gypsum.
Then, along the thickness direction of the gypsum core, from one surface side to the other surface side, three regions of equal thickness, a first end region, a central region, and a second end region, are formed. In the case of, the content of the magnetic material in the first end region can be made larger than the content of the magnetic material in the central region.

The gypsum-containing plate of the present embodiment will be described with reference to FIG.

FIG. 1 shows a perspective view of the gypsum core 10 of the gypsum-containing plate of the present embodiment. The gypsum core 10 of the present embodiment has a plate-like shape as shown in FIG. 1, and has one surface 11 and the other surface 12. A side surface 13 is arranged between one surface 11 and the other surface 12.

Although the gypsum core 10 has a rectangular parallelepiped shape, the gypsum-containing plate containing the gypsum core 10 can be used as a building material, etc., and is not limited to such a form, and may have an appropriate shape according to the application. it can.

Further, the specific form of the gypsum-containing plate of the present embodiment is not particularly limited, and is, for example, from the gypsum board specified by JIS A 6901 (2014) and the gypsum board specified by JIS A 6901 (2014). Lightweight or heavy gypsum board (hereinafter, regardless of whether the weight meets the above JIS standard, the above-mentioned gypsum board is also collectively referred to as gypsum board), glass mat gypsum board, gypsum containing glass fiber non-woven fabric. Examples include a containing plate and a slag gypsum-containing plate. The gypsum-containing plate of the present embodiment can be preferably used as a material constituting the wall of a building. The gypsum-containing board is preferably gypsum board because it is widely used as a wall material or the like. The gypsum board referred to here means a gypsum board specified by JIS A 6901 (2014) as described above, or a gypsum board that is lighter or heavier than the gypsum board specified by JIS A 6901 (2014). The gypsum board that is lighter than the gypsum board specified in JIS A 6901 (2014) is preferably a gypsum board having a specific gravity of 0.3 or more and less than 0.65, and is specified in JIS A 6901 (2014). The gypsum board that is heavier than the gypsum board to be made is, for example, a gypsum board having a specific gravity of more than 1.45 and 5.0 or less.

Therefore, in the gypsum-containing plate of the present embodiment, for example, a base paper for a board, a glass mat, or the like is further arranged as a surface material on one surface 11 or the other surface 12 of the gypsum core 10, depending on various forms. You can also do it. Further, a glass fiber non-woven fabric (glass tissue) or the like can be embedded in one surface 11 or the other surface 12. In addition, a gypsum-containing plate made of only the gypsum core 10 may be formed without arranging the surface material on one surface 11 of the gypsum core 10 or the other surface 12.

Then, the gypsum core 10 of the gypsum-containing plate of the present embodiment is formed along the thickness direction by three regions having the same thickness, that is, a first end region 141, a central region 142, and a second end portion. When the region 143 is set, the content of the magnetic material in the first end region 141 is preferably higher than the content of the magnetic material in the central region 142.

The thickness direction of the gypsum core 10 means the Z-axis direction in FIG. 1, which is a direction perpendicular to one surface 11 and the other surface 12. Then, when the thickness of the gypsum core 10 is t as shown in FIG. 1, the thickness of the first end region 141, the central region 142, and the second end region 143 is t / 3, respectively.

This is because when the magnetic material is uniformly dispersed in the gypsum core 10, a large amount of magnetic material is dispersed in the gypsum core 10 so that the magnet can be attracted to the surface of the gypsum-containing plate containing the gypsum core 10. This causes the gypsum-containing plate to become heavier and less handleable. There is also a problem that the cost of the gypsum-containing plate increases as the content of the magnetic material increases.

Therefore, in the gypsum-containing plate of the present embodiment, the gypsum core contained in the gypsum-containing plate contains gypsum that can attract magnets while suppressing the content of the magnetic material by unevenly distributing the magnetic material on the surface side. It can be a board. More specifically, a gypsum-containing plate capable of attracting a magnet on at least one surface 11 side of the gypsum core 10 can be used.

In the gypsum core 10, for example, the magnetic material may be unevenly distributed in both the first end region 141 and the second end region 143. That is, in the gypsum core 10, magnetic materials may be unevenly distributed on one surface 11 side and the other surface 12 side. In this case, the content of the magnetic material in the second end region 143 can also be higher than the content of the magnetic material in the central region 142. Then, in this case, a gypsum-containing plate capable of attracting a magnet can be formed on one surface 11 of the gypsum core 10 and the surface on the other surface 12 side.

By unevenly distributing the magnetic material in both the first end region 141 and the second end region 143 in this way, the surface where the magnetic material is unevenly distributed is confirmed in the gypsum-containing plate containing the gypsum core. It is preferable because it can be used without any problem and the handleability at the time of construction is improved.

Further, in the gypsum core 10, the content of the magnetic material in the first end region 141 can be made higher than the content of the magnetic material in the second end region 143. That is, the gypsum core 10 can be configured such that the magnetic material is unevenly distributed only on one surface 11 side. In this case, the content of the magnetic material in the first end region 141 can be higher than the content of the magnetic material in the central region 142 and the second end region 143.

By unevenly distributing the magnetic material only in the first end region 141 in this way, the amount of the magnetic material contained in the gypsum core 10 can be suppressed, and the weight and cost of the gypsum-containing plate containing the gypsum core can be suppressed. Can be suppressed, which is preferable. When the magnetic material is unevenly distributed only on one surface 11 side, a mark or the like is placed on any surface of the gypsum-containing plate so that the one surface 11 side can be identified when the gypsum-containing plate is used. It is preferable to attach it.

The proportion of the magnetic material present in the first end region 141 is not particularly limited, but is preferably 35% by mass or more, preferably 40% by mass or more, of the magnetic material contained in the gypsum core 10, for example. More preferably. Since the magnetic material can be unevenly distributed only in the first end region 141 as described above, the magnetic material existing in the first end region 141 is 100 mass of the magnetic material contained in the gypsum core. It can be less than or equal to%.

Further, when the magnetic material is unevenly distributed in both the first end region 141 and the second end region 143, the magnetic material existing in the second end region 143 is also included in the gypsum core 10. It is preferably 35% by mass or more, and more preferably 40% by mass or more of the magnetic material. However, in this case, the proportion of the magnetic material present in each of the first end region 141 and the second end region 143 is preferably 50% by mass or less.

As described above, in the gypsum-containing plate of the present embodiment, a board base paper, a glass mat, a glass fiber non-woven fabric, or the like can be arranged on or near the surface of the gypsum core according to the form. Therefore, when analyzing the distribution of the magnetic material in the gypsum core, the gypsum core can be divided into three along the thickness direction after removing the base paper for the board and the like, and the divided regions can be analyzed. ..

Specifically, although it depends on the thickness of the gypsum-containing plate, for example, by removing 1 mm of the thickness of the gypsum-containing plate from the surface, the base paper for the board arranged on the surface can be removed. Then, the gypsum core obtained by removing the surface of the gypsum-containing plate is divided into three regions having the same thickness along the thickness direction, and the first end region and the center are in order from one surface side. The region can be used for analysis as a second end region. The method of analyzing the content ratio of the magnetic material existing in each region is not particularly limited, and for example, each region is analyzed by a chemical analysis, a method of evaluating magnetism, a method of separating the magnetic material and evaluating its mass, and the like. can do. Specifically, for example, a method of separating the magnetic material contained in each region by the following procedure, measuring the mass thereof, and calculating the content ratio can be mentioned.

First, a sieve having a size finer than the size of the magnetic material used, for example, a particle size, that is, a small mesh size is prepared, and the gypsum core of each divided region is washed with water on the sieve to dissolve the gypsum. , Take out the magnetic material contained in each region on the sieve. Then, by measuring the mass of the residue on the sieve, the mass of the magnetic material contained in each region can be evaluated. Then, the content ratio of the magnetic material existing in each region can be calculated from the mass of the magnetic material contained in each region evaluated by the above procedure.

The magnetic material is not particularly limited, and various magnetic materials capable of attracting magnets can be used.

Examples of the magnetic material include iron powder such as iron oxide powder, reduced iron powder, and atomized iron powder, a resin sheet in which magnetic material powder is kneaded, a composite sheet including a metal plate, a steel foil, and a metal such as an iron plate and a steel plate. It is preferable to use one or more selected from plates and the like.

In addition, a resin sheet in which magnetic material powder is kneaded, a composite sheet including a metal plate, a sheet-shaped magnetic material such as a metal plate has a plurality of openings formed like a mesh or a punching sheet. You may be. Since the openings are formed in this way, the gypsum slurry and the magnetic material are easily compatible with each other and have good air permeability when manufacturing a gypsum core or a gypsum-containing plate containing the gypsum core, so that the gypsum core is dried. It is preferable that water is easily removed.

Examples of the composite sheet including the metal plate include steel paper, which is a composite material of steel foil and paper.

When a steel plate is used as the metal plate, the steel plate is a steel plate plated with a single metal such as a galvanized steel plate (galvanized steel plate), that is, a single metal plated steel plate or a galvanized steel plate (registered trademark) with a molten 55%. One or more types selected from steel sheets plated with an alloy such as aluminum-galvanized steel sheets, that is, alloy-plated steel sheets and the like can be used. Further, the metal plate is preferably thin from the viewpoint of reducing the weight of the gypsum-containing plate containing the metal plate and improving the workability, and more preferably a metal foil (magnetic material foil) such as a steel foil.

In particular, the magnetic material preferably has a powder shape from the viewpoint of handleability. As the magnetic material, it is more preferable to use one or more types of iron powder selected from iron oxide powder, reduced iron powder, atomized iron powder and the like from the viewpoint of cost and handleability. When iron powder is used as the magnetic material, its average particle size is not particularly limited, but is preferably 100 nm or more, for example. This is because the handleability can be improved by setting the nm to 100 nm or more. The upper limit of the average particle size of iron powder is also not particularly limited, but for example, the average particle size of iron powder is preferably 200 μm or less. By setting the average particle size of the iron powder to 200 μm or less, it is possible to suppress damage to a cutting device such as a cutter used for cutting the gypsum-containing plate to a desired size when manufacturing the gypsum-containing plate. Because it can be done.

The average particle size means the particle size (median diameter) at an integrated value of 50% in the particle size distribution obtained by the laser diffraction / scattering method. Hereinafter, unless otherwise specified in the present specification, the average particle size has the same meaning.

Further, for example, when it is required to enhance the nonflammability of a gypsum-containing plate, it is more preferable to use iron oxide powder as the iron powder. The type of iron oxide contained in the iron oxide powder is not particularly limited, but ferric tetroxide (Fe ₃ O ₄ ) can be particularly preferably used.

When a composite sheet containing a metal plate or a metal plate is used as the magnetic material, the thickness of the gypsum core containing the magnetic material or the gypsum-containing plate can be selected so that it can be easily cut with a cutter or the like. preferable. In particular, for a metal plate, it is preferable to use a metal foil so that it can be easily cut. When a composite sheet containing a metal plate or a metal plate is used, its thickness is not particularly limited and can be selected depending on the material, but for example, it is preferably 1 mm or less, preferably 0.8 mm or less. Is more preferable. The lower limit of the thickness can be selected so that the magnet can be attracted, but can be, for example, 0.1 mm or more.

By using a magnetic material such as iron powder, a resin sheet in which magnetic material powder is kneaded, a composite sheet containing a metal plate, or a metal plate that can be easily cut with a cutter, the workability of the gypsum-containing plate can be improved. It can be a gypsum-containing plate with magnets attached without damage.

The content of the magnetic material of the gypsum-containing plate of the present embodiment is not particularly limited because it can be arbitrarily selected according to the type of the magnetic material, the magnetic properties, and the like. The content of the magnetic material of gypsum-containing plate of the present embodiment is preferably for example at unit area per 0.3 kg / m ² or more one surface, more preferably 0.8 kg / m ² or more.

This is because by setting the content per unit area of one surface to 0.3 kg / m ² or more, a magnetic material such as a magnet can be adsorbed on the surface of the gypsum-containing plate with sufficient adsorption force. Is.

The upper limit of the content of the magnetic material of the gypsum-containing plate per unit area is not particularly limited, and can be arbitrarily selected depending on, for example, the adsorption force and cost required for the gypsum-containing plate. The content of the magnetic material of the gypsum-containing plate per unit area is preferably, for example, 10 kg / m ² or less.

The gypsum core of the gypsum-containing plate of the present embodiment may contain any component other than gypsum and the magnetic material. For example, adhesiveness added to raw materials in the manufacturing method of gypsum-based building materials such as gypsum board, hardening adjusting materials such as accelerators and delaying materials, fiber materials such as glass fibers, and gypsum-containing boards, which are generally used. It can also contain various arbitrary additives such as improvers. Further, for example, a thickener, a defoaming agent, a pigment for adjusting the color of the magnetic material, a filler (bulking material) and the like can be contained. As will be described later in the method for producing a gypsum-containing plate, which will be described later, bubbles can be added to the gypsum slurry used when producing the gypsum-containing plate, and the gypsum-containing plate of the present embodiment can be added in response to the bubbles. The gypsum core of is also capable of containing air bubbles (voids).

Further, when a material having a possibility of causing rust such as an iron-based material is used as the magnetic material, a rust preventive agent may be contained. It may also contain a magnetic material that has been subjected to a rust preventive treatment.

When the gypsum core contains a rust preventive, the rust preventive is preferably contained in a proportion of 0.1% by mass or more, more preferably 0.3% by mass or more, based on the magnetic material. preferable.

When the gypsum core contains a rust preventive, the upper limit of the content is not particularly limited, but even if it is added excessively, the rust preventive effect does not change significantly and the strength of the gypsum core decreases. There is a risk of doing. Therefore, the gypsum core preferably contains a rust preventive in a proportion of 20% by mass or less with respect to a magnetic material such as iron powder.

The type of rust inhibitor is not particularly limited, but the rust inhibitor is, for example, a water-soluble or emulsion organic acid-based rust inhibitor, chelate-based rust inhibitor, organic acid amine-based rust inhibitor, fatty acid-based rust inhibitor. It is preferable to contain one or more selected from rust agents and nitrite-based rust preventives.

Up to this point, the members included in the gypsum-containing plate of the present embodiment have been described, but the characteristics of the gypsum-containing plate of the present embodiment will be described below.

The gypsum-containing plate of the present embodiment preferably has a smooth surface.

Here, the fact that the surface (main surface) of the gypsum-containing plate of the present embodiment is smooth means that the thickness variation is 500 μm or less when the thickness of the gypsum-containing plate is measured at a plurality of points. are doing.

The thickness of the gypsum-containing plate can be measured in the same manner as specified in "a) Thickness" of "7.3.1 Dimensions" of JIS A 6901 (2014). Specifically, the thickness can be measured at 6 measurement positions at equal intervals in a region within 25 mm from the end face of the gypsum-containing plate as a sample and 80 mm or more inside from both side surfaces. Therefore, it can be said that the surface is smooth when the measured thickness variation at the six locations is 500 μm or less.

Since the surface of the gypsum-containing plate is smooth, a flat wall can be formed when used as a wall material or the like, which is preferable. In addition, because the surface of the plaster-containing board is smooth, the surface of the plaster-containing board can be covered with wallpaper (wallpaper finish) by pasting wallpaper, paint finish by applying paint, and makeup finish such as laminating. By arranging the decorative magnet, it becomes possible to easily finish the decorative magnet. The decorative magnet finish means finishing the surface of the wall by adsorbing a wallpaper, a decorative plate, or a decorative paper on which a magnet is arranged on one surface to a plaster-containing plate by the magnet.

Further, it is preferable that the gypsum-containing plate of the present embodiment has a thickness t satisfying the standard of JIS A 6901 (2014).

Satisfying the JIS A 6901 (2014) standard means that the thickness of the gypsum-containing plate is 9.5 mm or more and 10.0 mm or less, 12.5 mm or more and 13.0 mm or less, 15.0 mm or more and 15.5 mm or less, 16 It means that it belongs to any range of 0.0 mm or more and 16.5 mm or less, 18.0 mm or more and 18.5 mm or less, 21.0 mm or more and 21.5 mm or less, and 25.0 mm or more and 25.5 mm or less.

This means that when the thickness t of the gypsum-containing board meets the standard of JIS A 6901 (2014), the thickness of the gypsum-containing board meets the same standard as the thickness of the gypsum-based building material usually used. Will be there. Therefore, for example, even when a wall or the like is formed by using the gypsum-containing plate of the present embodiment and a normal gypsum-based building material at the same time, unevenness depending on the type of gypsum-based building material used without adjusting the thickness or the like. This is because it is possible to easily form a flat wall without gypsum, that is, a flat wall, which is preferable.

The thickness t of the gypsum-containing plate is 9.5 mm or more and 10.0 mm or less, 12.5 mm or more and 13.0 mm or less, 15.0 mm or more and 15.5 mm or less, similar to the more commonly used gypsum-based building materials. It is more preferable that it belongs to any range of 21.0 mm or more and 21.5 mm or less.

The thickness of the gypsum-containing plate can be evaluated by the method specified in JIS A 6901 (2014).

The gypsum-containing plate of the present embodiment preferably satisfies the semi-incombustible performance. That is, it is preferable that the gypsum-containing plate of the present embodiment is certified as a semi-incombustible material. Semi-incombustible is defined in Article 1, Item 5 of the Building Standards Act Construction Ordinance. In order to be recognized as a semi-incombustible material, it must not burn for 10 minutes after the start of heating when the heat of a normal fire is applied, and it does not cause harmful deformation, melting, cracking or other damage in terms of fire prevention. It is required to satisfy that it is a thing and does not generate harmful smoke or gas for evacuation.

Further, the gypsum-containing plate of the present embodiment preferably satisfies the non-combustible performance. That is, it is preferable to be certified as a non-combustible material. Incombustible is defined in Article 2, Item 9 of the Building Standards Act and Article 108-2 of the Building Standards Act Construction Ordinance. In order to be recognized as a non-combustible material, it must not burn for 20 minutes after the start of heating when the heat of a normal fire is applied, and it does not cause harmful deformation, melting, cracking or other damage in terms of fire prevention. It is required to satisfy that it does not generate harmful smoke or gas for evacuation. According to the interior restrictions of the Building Standard Law, the building materials that can be used are quasi-non-combustible materials or non-combustible materials depending on the purpose and scale of the building. The gypsum-containing plate of the present embodiment can adapt to the interior restrictions required by the building to be used, that is, it can be a semi-incombustible material or a non-combustible material, and therefore can be used in a building of any use and scale. it can.

The specific method for the gypsum-containing plate of the present embodiment to satisfy the semi-incombustible or non-combustible performance is not particularly limited. For example, by selecting a non-flammable material for a gypsum-containing plate such as a magnetic material, a gypsum-containing plate satisfying semi-incombustible and non-combustible performance can be obtained.

As described above, the gypsum-containing plate of the present embodiment can adsorb a magnetic material such as a magnet by containing a magnetic material. The attractive force of the magnet is not particularly limited, but for example, it is preferable to satisfy the following characteristics of the magnet attraction test.

First, as shown in FIG. 2, the gypsum-containing plate 21 of the present embodiment is erected so that one surface 21a, which is the main surface, is vertical. Then, one magnet 22 having a diameter of the magnet portion of 17 mmφ and an attraction force to the 1 mm iron plate of 3.5 N is used, and one sheet of A4 paper 23 is attached to one surface 21a by the magnet. In this case, it is preferable that the A4 paper has an attractive force that does not drop.

Further, it is more preferable that the wallpaper has the same characteristics when the wallpaper is arranged on the main surface of the gypsum-containing plate. That is, the gypsum-containing plate 21 having the wallpaper applied to one surface 21a is erected so that the one surface 21a is vertical. Then, one magnet 22 having a magnet portion having a diameter of 17 mmφ and an attraction force to a 1 mm iron plate of 3.5 N is used, and one sheet of A4 paper 23 is attached to one surface 21a by the magnet. In this case, it is preferable that the A4 paper 23 has an adsorption force that does not drop.

When the magnetic material is unevenly distributed in the second end region, one of the above-mentioned ones when the magnet adsorption test is similarly performed on the other surface which is the main surface on the second end region side. It is preferable to show the same adsorption force as the surface.

When the wallpaper is placed on the main surface of the gypsum-containing plate and the magnet adsorption test is performed, for example, a wallpaper having a thickness of 0.3 mm, which is generally used, can be used as the wallpaper. As the wallpaper, for example, a vinyl cloth or the like can be used.

Further, in any of the above-mentioned magnet adsorption tests, as the A4 paper, A4 paper having a thickness of 0.09 mm and a mass of 64 g / m ² can be preferably used. Further, not limited to the present magnet adsorption test, in the present specification, as the A4 paper, A4 paper having the above-mentioned thickness and mass can be preferably used.

The positions of the magnet 22 and the A4 paper 23 are not particularly limited, but the distance L between the center of the magnet 22 and the upper end of the A4 paper 23 is preferably 3 cm, and the center of the magnet 22 is A4. It is preferable that the paper 23 is arranged at the center in the width direction.

Although the gypsum-containing plate of the present embodiment has been described above, since the gypsum-containing plate of the present embodiment contains a magnetic material, it can attract magnets. Then, in the gypsum-containing plate of the present embodiment, when the gypsum core is formed into three regions of equal thickness, a first end region, a central region, and a second end region, along the thickness direction. , The content of the magnetic material in the first end region is higher than the content of the magnetic material in the central region. That is, in the gypsum-containing plate of the present embodiment, the gypsum core contained in the gypsum-containing plate contains gypsum that can attract magnets while suppressing the content of the magnetic material by unevenly distributing the magnetic material on the surface side. It can be a board.

Further, according to the gypsum-containing plate of the present embodiment, since the magnetic material is only unevenly distributed in the gypsum core, it can be easily cut or processed into a free shape.

Further, in the plaster-based building material in which a conventionally used iron plate is arranged and fixed on the surface, it is difficult to hit screws or nails due to the iron plate, so that it is difficult to fasten the gypsum-containing plate. was there. Further, there is a problem that the adhesiveness with the wallpaper or the paint is lowered when finishing by the wallpaper or the paint.

On the other hand, according to the gypsum-containing plate of the present embodiment, since the magnetic material is arranged in the gypsum core of the gypsum-containing plate, nails, screws, and the like can be easily hit. Further, the adhesiveness to the wallpaper and the paint can be made sufficiently high.
[Manufacturing method of gypsum-containing plate]
Next, a configuration example of the method for manufacturing the gypsum-containing plate of the present embodiment will be described. The above-mentioned gypsum-containing plate can be produced by the method for producing a gypsum-containing plate of the present embodiment. Therefore, some of the matters already described will be omitted.
(First configuration example)
The first configuration example of the method for producing a gypsum-containing plate of the present embodiment can have the following steps.
A kneading step of kneading at least gypsum and a raw material containing water to form a gypsum slurry.
A molding process in which a gypsum slurry is molded to form a molded body.
A curing step of curing a molded product obtained in the molding process.

Then, in the molding step, the magnetic material can be arranged on the surface side of the molded body.

Hereinafter, each step will be described.

First, the kneading process will be described.

In the kneading step, the gypsum and the raw material containing water can be kneaded.

Here, the gypsum contained in the raw material is also referred to as calcium sulfate 1/2 hydrate, and is an inorganic composition having hydraulic property. As the gypsum used in the method for producing the gypsum-containing plate of the present embodiment, gypsum alone or mixed such as natural gypsum, by-product gypsum and flue gas desulfurization gypsum is fired in the air or water (including in steam). Either the obtained α-type or β-type desulfurized gypsum can be used alone, or a mixture of both can be used. Further, the gypsum used in the method for producing a gypsum-containing plate of the present embodiment may contain a small amount of type III anhydrous gypsum that is produced when the gypsum is obtained.

For α-type gypsum, it is necessary to bake dihydrate gypsum such as natural gypsum under pressure in water or steam using an autoclave. Further, β-type gypsum can be produced by firing dihydrate gypsum such as natural gypsum at normal pressure in the atmosphere.

Next, the water added when preparing the gypsum slurry will be described.

Water can be added to knead gypsum or the like into a gypsum slurry. The amount of water added when forming the gypsum slurry is not particularly limited, and can be any amount depending on the required fluidity and the like.

The raw material of the gypsum slurry can contain any component other than the gypsum and water described above.

For example, bubbles can be added when forming the gypsum slurry. The specific gravity of the gypsum-containing plate obtained by adjusting the amount of foam added can be in a desired range.

The method of adding foam when forming the gypsum slurry is not particularly limited, and the foam can be added by any method. For example, a foaming agent (foaming agent) is added to water (water for forming bubbles) in advance, and bubbles are formed by stirring while taking in air, and the formed bubbles are mixed with roasted gypsum or water (kneaded water of gypsum slurry). ), To form a gypsum slurry with added foam. Alternatively, a gypsum slurry to which bubbles have been added can be obtained by adding the formed bubbles to a gypsum slurry formed by previously mixing calcined gypsum and water or the like.

The foaming agent used for forming the foam is not particularly limited, and examples thereof include sodium alkyl sulfate, alkyl ether sulfate, sodium alkylbenzene sulfonic acid, and polyoxyethylene alkyl sulfate.

The amount of foam added is not particularly limited, and can be arbitrarily selected according to the specific gravity required for the gypsum-containing plate to be produced.

In addition, the raw materials are various arbitrary components described in the gypsum-containing plate, adhesiveness improvers such as starch and polyvinyl alcohol that improve the adhesiveness between the coating material and the gypsum core, and inorganic fibers such as glass fiber. As a raw material for hardened gypsum, such as lightweight aggregates, fireproof materials such as vermiculite, coagulation adjusters, water reducing agents, foam diameter adjusting agents such as sulfosuccinate-type surfactants, and water repellents such as silicone and paraffin It can also contain various additives to be added.

When the raw materials are kneaded to prepare the gypsum slurry, all the components constituting the raw materials may be kneaded at the same time, but the kneading may be carried out in a plurality of times. For example, after mixing and kneading solid components of raw materials to form a gypsum composition, liquid components such as water of the raw materials are added to the obtained gypsum composition and further kneaded to obtain a gypsum slurry. You can also.

The means for kneading the raw materials is not particularly limited, and for example, a mixer or the like can be used.

The obtained gypsum slurry can be molded into a desired shape in the molding step. Specifically, since it is a gypsum-containing plate, it can be molded into, for example, a plate shape.

Here, a configuration example of a kneading step, a molding step, and a hardening step when manufacturing gypsum board will be described with reference to FIG. FIG. 3 is a side view showing a configuration example of a device for molding gypsum board partially and schematically.

The surface cover base paper (board base paper) 31, which is a surface material, is conveyed from the right side to the left side in the drawing along the production line.

The mixer 32 can be placed in a predetermined position associated with the transport line, eg, above or beside the transport line. Then, in a single mixer 32, gypsum slurry, which is a raw material of gypsum slurry, water, and, in some cases, various additives can be kneaded to produce gypsum slurry (kneading step).

As described above, a solid such as gypsum can be mixed and stirred in advance to form a gypsum composition which is a mixture, and then supplied to the mixer 32.

Further, bubbles can be added from the gypsum slurry collection ports 321, 322, and 325, and the amount of bubbles added can be adjusted to obtain a gypsum slurry having an arbitrary density. For example, by adjusting the amount of foam added, the first gypsum slurry 33 and the second gypsum slurry 34 having different densities can be prepared.

Then, the obtained first gypsum slurry 33 is passed through the delivery pipes 323 and 324 on the front cover base paper (board base paper) 31 and the back cover base paper (board base paper) 36 on the upstream side in the transport direction of the roll coater 35. Supply to.

Here, the roll coater 35 can have a coating roll 371, a receiving roll 372, and a waste removing roll 373. The first gypsum slurry 33 on the front cover base paper 31 and the back cover base paper 36 each reaches the extension portion of the roll coater 35 and is extended at the extension portion. A thin layer of the first gypsum slurry 33 is formed on the surface cover base paper 31. Similarly, a thin layer of the first gypsum slurry 33 is formed on the back cover base paper 36. Note that FIG. 3 shows an example in which the first gypsum slurry 33 is applied to the front cover base paper 31 and the back cover base paper 36 using the roll coater 35, but the present invention is not limited to this form. For example, the roll coater 35 may be used to apply the first gypsum slurry 33 to only one of the front cover base paper 31 and the back cover base paper 36. Further, the surface cover base paper 31 can be provided with a plurality of engraved lines parallel to the transport direction in the vicinity of the end portion in the width direction thereof, and the surface cover base paper 31 is bent along the engraved lines to be described later. It can also be configured to cover a part of the side surface and the upper surface of the gypsum slurry 34 of 2. In this case, the first gypsum slurry 33 is placed on the side edge of the surface cover base paper 31 so that the thin layer of the first gypsum slurry 33 is arranged only on the side surface and a part of the upper surface of the second gypsum slurry 34. It can also be placed only in.

The front cover base paper 31 is conveyed as it is, and the back cover base paper 36 is turned in the direction of the transfer line of the front cover base paper 31 by the turning roller 38. Then, both the front cover base paper 31 and the back cover base paper 36 are conveyed in the same direction and reach the molding machine 39. Here, the second gypsum slurry 34 is supplied from the mixer 32 through the pipe line 326 between the thin layers formed on the front cover base paper 31 and the back cover base paper 36.

Then, the gypsum slurry can be molded by the molding machine 39 to form a molded body (molding step). Next, in the process of transporting the molded product, a curing step of hydrating and curing the gypsum slurry described later can be carried out.

FIG. 3 shows an example in which the first gypsum slurry 33 and the second gypsum slurry 34 are produced by one mixer 32. However, two mixers are provided, and each mixer has the first gypsum slurry 33. , The second gypsum slurry 34 may be produced.

Further, the form is not limited to the use of the first gypsum slurry and the second gypsum slurry, for example, in the form of producing one kind of density gypsum slurry and supplying it on the base paper for board. There may be.

Specifically, for example, a gypsum slurry having a predetermined density is supplied and deposited on a surface cover base paper (board base paper) that is continuously conveyed. Then, the lower paper is folded along the engraved lines attached to both end edges so as to wrap the gypsum slurry. At this time, the back cover base paper (board base paper) transported at the same speed is overlaid on the layer of the gypsum slurry. Then, it is molded by passing through a molding machine that determines the thickness and width of the gypsum board. Gypsum board can also be molded by the above procedure.

Then, in the molding step, the magnetic material can be arranged on the surface side of the molded body. The surface side of the molded product referred to here means one or both of one surface 11 and the other surface 12 in the case of the gypsum core shown in FIG. 1.

The specific method for arranging the magnetic material on the surface side of the molded product is not particularly limited. For example, a method of arranging the magnetic material in advance on one or both of the surface 31A on the side of the front cover base paper 31 in contact with the gypsum slurry and the surface 36A of the back cover base paper 36 on the side in contact with the gypsum slurry can be mentioned. The magnetic material is arranged in advance on the surface of the cover base paper on the side in contact with the gypsum slurry, and the gypsum slurry is arranged and molded between the cover base papers as described above to arrange the magnetic material on the surface side of the molded body. Can be done. The method of arranging the magnetic material on the surface of the cover base paper in contact with the gypsum slurry is not particularly limited, but when the magnetic material has a powder shape, a method of dispersing the magnetic material in a solvent, gypsum slurry, or the like is used. be able to. When the magnetic material has a sheet shape, a method of attaching the magnetic material to the surface of the cover base paper in contact with the gypsum slurry can be used.

Further, as a method of arranging the magnetic material on the surface side of the molded product, for example, a method of adding the magnetic material to the above-mentioned first gypsum slurry 33 can be mentioned. The first gypsum slurry 33 can be supplied onto the front cover base paper 31 and the back cover base paper 36 and applied by the roll coater 35 as described above. Therefore, by adding the magnetic material to the first gypsum slurry 33, the magnetic material is arranged on the surface side of the molded product. When the magnetic material is added to the first gypsum slurry 33, for example, the magnetic material can be added to the first gypsum slurry 33 supplied to either the front cover base paper 31 or the back cover base paper 36. It should be noted that a plurality of means can be used in combination. For example, the magnetic material can be arranged on the surface of the cover base paper in contact with the gypsum slurry, and the magnetic material can be added to the first gypsum slurry 33.

The specific method for adding the magnetic material to the first gypsum slurry 33 is not particularly limited, but for example, the magnetic material is added to the gypsum slurry produced by the mixer 32 at either one or both of the preparative ports 321 and 322. There is a way to do it. Further, a mixer is provided separately from the mixer 32, and the raw materials containing the gypsum, the magnetic material, and water are kneaded, or the magnetic material is added to the gypsum slurry produced by the mixer 32 and re-kneaded to obtain magnetism. A gypsum slurry containing the material can also be produced. When the magnetic material is added, other additive components such as bubbles can also be added. Then, the gypsum slurry can be supplied on the cover base paper as the first gypsum slurry 33.

As the magnetic material, the gypsum-containing plate and the above-mentioned material can be used, and thus the description thereof will be omitted here.

Although the gypsum board has been described as an example here, the base paper for the board, which is the surface material, should be changed to a glass fiber non-woven fabric (glass tissue), a glass mat, etc., and this should be buried on or near the surface. It is also possible to manufacture various gypsum-containing plates by arranging them in.

Next, a curing step of hydrating and curing the gypsum slurry can be carried out.

The hardening step can be carried out by allowing acicular crystals of dihydrate gypsum to be formed by a hydration reaction of the baked gypsum (hemihydrate gypsum) in the gypsum slurry to condense and solidify. Therefore, the hardening step can be carried out by reacting between the gypsum contained in the gypsum slurry and water in the molded body formed in the molding step and the hydration reaction of the gypsum progresses.

Further, the gypsum-containing plate manufacturing method of the present embodiment may be further provided with an arbitrary step such as a rough cutting step, a drying step, a cutting step, and a loading step, if necessary.

For example, after the above-mentioned molding step, a rough cutting step of roughly cutting the molded product formed in the molding step with a rough cutting cutter may be performed while the curing step is in progress or after the curing step is completed. In the rough cutting step, the rough cutting cutter can cut the continuous molded body formed in the molding step to a predetermined length.

Further, it is possible to carry out a drying step of drying the excess water of the molded product molded in the molding step or the molded product roughly cut in the rough cutting step. In the drying step, it is possible to supply a molded product having completed the curing step. The drying step can be carried out by forcibly drying the molded product using a dryer.

The method for forcibly drying the molded body with a dryer is not particularly limited, but for example, a dryer is provided on the transport path of the molded body, and the molded body is continuously dried by passing through the dryer. can do. It is also possible to carry the molded product into the dryer and dry the molded product for each batch.

Furthermore, for example, a cutting process in which a molded product is dried and then cut into a product of a predetermined length, and a truck for stacking the obtained gypsum-containing plates with a lifter or the like and storing or shipping them in a warehouse. It is possible to carry out a loading process or the like.

According to the method for producing a gypsum-containing plate of the present embodiment described above, in the molding step, by arranging the magnetic material on the surface side of the molded body, the gypsum core is made of the magnetic material in the first end region. A gypsum-containing plate having a content higher than that of the magnetic material in the central region can be obtained.
(Second configuration example)
The second configuration example of the method for producing a gypsum-containing plate of the present embodiment can have the following steps.
A kneading step of kneading raw materials containing at least gypsum, water, and a magnetic material to form a gypsum slurry.
A molding process in which a gypsum slurry is molded to form a molded body.
A curing step of curing a molded product obtained in the molding process.
Then, in the kneading step, the viscosity of the gypsum slurry can be set to 5 cps or more and 100 cps or less, and the setting time of the gypsum slurry, which is the time until the gypsum slurry loses its fluidity, can be set to 30 seconds or more and 180 seconds or less.

Each step will be described below. In addition, a part of description will be omitted about the point that can be carried out in the same manner as the first configuration example.

First, the kneading process will be described.

In the kneading step, raw materials containing gypsum, water, and a magnetic material can be kneaded.

Here, since the same gypsum, magnetic material, and water contained in the raw materials as those described in the first configuration example can be used, the description thereof will be omitted here. However, as the magnetic material to be kneaded with gypsum or water, a material having a powder shape can be preferably used.

Further, the raw material may further contain various additives in addition to the above-mentioned gypsum and the like. Since examples of various additives have been described in the first configuration example, description thereof will be omitted here.

Then, in this configuration example, in the kneading step, the gypsum slurry can be kneaded so that the viscosity is 5 cps or more and 100 cps or less. By kneading the gypsum slurry so that the viscosity is 100 cps or less, the magnetic material in the gypsum slurry is lowered by its own weight in the process of being conveyed after forming the molded product in the molding step, that is, shown in FIG. If it is a gypsum-containing plate manufacturing apparatus, it can be moved to the surface cover base paper 31 side. Therefore, the gypsum core can be a gypsum-containing plate in which the content of the magnetic material in the first end region is larger than the content of the magnetic material in the central region.

However, if the viscosity of the gypsum slurry is too low, it may be difficult to form a molded product. Therefore, the viscosity of the gypsum slurry is preferably 5 cps or more.

The viscosity of the gypsum slurry can be measured by, for example, a Brookfield viscometer (B-type viscometer). The viscosity of the gypsum slurry is preferably, for example, the viscosity of the gypsum slurry immediately after the raw materials are kneaded with a mixer or the like, that is, immediately after the kneading step. In the present specification, the viscosity of the gypsum slurry can be similarly measured with the above-mentioned viscometer in other parts.

The method for adjusting the viscosity of the gypsum slurry is not particularly limited, but it can be adjusted by, for example, the amount of water added, the addition of additives, or the like.

In addition, as described with reference to FIG. 3 in the first configuration example, when preparing the first gypsum slurry and the second gypsum slurry, at least the central portion of the gypsum-containing plate is formed. The viscosity of the second gypsum slurry is preferably in the above range. The viscosities of both the first gypsum slurry and the second gypsum slurry can be in the above range.

The content of the magnetic material may be different between the first gypsum slurry and the second gypsum slurry. Specifically, for example, the gypsum slurry can be prepared so that the content of the magnetic material per unit volume of the first gypsum slurry is higher than that of the second gypsum slurry. With such a configuration, it is possible to more reliably obtain a gypsum-containing plate in which the content of the magnetic material in the first end region is larger than the content of the magnetic material in the central region of the gypsum core. However, when the content of the magnetic material in the first end region is larger than the content of the magnetic material in the second end region, for example, the first gypsum slurry supplied to the surface cover base paper 31 side. The content of the magnetic material can be made higher than the content of the magnetic material in the second gypsum slurry. In this case, the magnetic material may not be added to the first gypsum slurry supplied to the back cover base paper 36 side, or the content of the magnetic material may be the same as that of the second gypsum slurry.

The form is not limited to the use of the first gypsum slurry and the second gypsum slurry. For example, one type of gypsum slurry is produced and supplied onto a board base paper. Is also good.

Here, a configuration example of a kneading step, a molding step, and a hardening step in manufacturing gypsum board will be described with reference to FIG. Since it has already been described in the first configuration example, some duplicate explanations will be omitted.

In the method for producing a gypsum-containing plate of this configuration example, a gypsum slurry can be produced by kneading gypsum, which is a raw material of gypsum slurry, water, a magnetic material, and in some cases, various additives in the mixer 32. (Kneading process). At this time, it is preferable to adjust the ratio of each component and the like so that the viscosity of the gypsum slurry is within the above-mentioned range as described above.

Then, the obtained first gypsum slurry 33 is passed through the delivery pipes 323 and 324 on the front cover base paper (board base paper) 31 and the back cover base paper (board base paper) 36 on the upstream side in the transport direction of the roll coater 35. Supply to. It can also be used in combination with the method of the first configuration example. Specifically, the magnetic material may be arranged in advance on either one or both of the surface 31A on the side of the front cover base paper 31 in contact with the gypsum slurry and the surface 36A of the back cover base paper 36 on the side in contact with the gypsum slurry. it can. Further, as described above, it can be added to the first gypsum slurry so that the content of the magnetic material per unit volume is larger than that of the second gypsum slurry.

The first gypsum slurry 33 on the front cover base paper 31 and the back cover base paper 36 each reaches the extension portion of the roll coater 35 and is extended at the extension portion. A thin layer of the first gypsum slurry 33 is formed on the surface cover base paper 31. Similarly, a thin layer of the first gypsum slurry 33 is formed on the back cover base paper 36.

The front cover base paper 31 is conveyed as it is, and the back cover base paper 36 is turned in the direction of the transfer line of the front cover base paper 31 by the turning roller 38. Then, both the front cover base paper 31 and the back cover base paper 36 are conveyed in the same direction and reach the molding machine 39. Here, the second gypsum slurry 34 is supplied from the mixer 32 through the pipe line 326 between the thin layers formed on the front cover base paper 31 and the back cover base paper 36.

Then, it can be molded by the molding machine 39 to form a molded body (molding step). Next, in the process of transporting the molded product, a curing step of hydrating and curing the gypsum slurry can be carried out.

The hardening step can be carried out by allowing acicular crystals of dihydrate gypsum to be formed by a hydration reaction of the baked gypsum (hemihydrate gypsum) in the gypsum slurry to condense and solidify. Therefore, the hardening step can be carried out by reacting between the gypsum contained in the gypsum slurry and water in the molded body formed in the molding step and the hydration reaction of the gypsum progresses.

In this configuration example, the setting time of the gypsum slurry is preferably 30 seconds or more and 180 seconds or less. By preparing the gypsum slurry having the viscosity described above in the kneading step, the magnetic material can easily move to the lower side, that is, to the surface cover base paper 31 side in the case of the example shown in FIG. 3, due to its own weight in the molded body. ing. However, if the setting time of the gypsum slurry is short, a cured product may be formed at a stage where the magnetic material is not sufficiently transferred. Therefore, from the viewpoint of sufficiently securing the time for the magnetic material to move in the molded body, the setting time of the gypsum slurry is preferably 30 seconds or more, more preferably 45 seconds or more. However, if the setting time in the curing step is excessively long, the productivity may decrease. Therefore, the setting time in the curing step is preferably 180 seconds or less, more preferably 165 seconds or less. ..

The setting time can be adjusted, for example, by adding an additive to the surrounding atmosphere when the molded product is being conveyed or to the gypsum slurry.

The setting time means the starting time in the setting time defined by JIS R 9112 (2015), and means the time until the slurry loses its fluidity.

The measurement of the setting time can be performed, for example, by the following procedure, as specified in the item of the starting time of the setting time of the JIS standard described above.
First, a cylindrical mold having an inner diameter of 78 ± 5 mm and a height of 40.0 ± 0.5 mm is placed on a glass plate, and a gypsum slurry to be evaluated is poured into the glass plate. Next, a metal needle having a length of 45 mm and a diameter of 2 mm and having its head cut flat is placed in the center of the gypsum slurry so as to be perpendicular to the glass plate and the flat cut side is located in the gypsum slurry. To do. Then, the time from when the gypsum and water come into contact with each other to prepare the gypsum slurry until the metal needle stops at a height of about 1 mm from the bottom surface of the gypsum slurry specimen placed in the cylindrical shape. Measure and use this as the first train time. The metal needle used has a total mass of 300 ± 1 g of a movable portion that descends when the flatly cut side is arranged in the gypsum slurry.

In the present specification, the setting time of the gypsum slurry has the same meaning.

Here, gypsum board has been described as an example, but the base paper for board, which is the surface material, is changed to glass fiber non-woven fabric (glass tissue), glass mat, etc., and this is arranged so as to be buried in or near the surface. It is also possible to manufacture various gypsum-containing plates.

After the curing step, various arbitrary steps described in the first configuration example can also be carried out.

According to the method for producing a gypsum-containing plate of the present embodiment described above, by preparing a gypsum slurry having a predetermined viscosity and setting the setting time in the curing step to a certain time or more, the magnetic material has its own weight in the molded body. The gypsum core can be a gypsum-containing plate in which the content of the magnetic material in the first end region is higher than the content of the magnetic material in the central region.
(Third configuration example)
A third configuration example of the method for producing a gypsum-containing plate of the present embodiment can have the following steps.
A kneading step of kneading raw materials containing at least gypsum, water, and a magnetic material to form a gypsum slurry.
A molding process in which a gypsum slurry is molded to form a molded body.
A step of uneven distribution of a magnetic material in which a gypsum slurry is conveyed on a transfer path in which magnets are arranged so as to face at least one surface of a molded product.
A curing step of curing a molded product that has completed the process of uneven distribution of magnetic materials.

Hereinafter, each configuration example will be described with reference to FIG.

Each step will be described below. In addition, a part of description will be omitted about the point that can be carried out in the same manner as the first configuration example.

First, the kneading process will be described.

In the kneading step, raw materials containing gypsum, water, and a magnetic material can be kneaded.

Here, since the same gypsum, magnetic material, and water contained in the raw materials as those described in the first configuration example can be used, the description thereof will be omitted here. However, as the magnetic material to be kneaded with gypsum or water, a material having a powder shape can be preferably used.

Further, the raw material may further contain various additives in addition to the above-mentioned gypsum and the like. Since examples of various additives have been described in the first configuration example, description thereof will be omitted here.

The viscosity of the gypsum slurry prepared in this configuration example is not particularly limited, but for example, as in the second configuration example, the gypsum slurry can be kneaded so that the viscosity is 5 cps or more and 100 cps or less. Further, as described with reference to FIG. 3 in the first configuration example, when the first gypsum slurry and the second gypsum slurry are prepared, the central portion of the gypsum-containing plate is formed. The viscosity of the second gypsum slurry can also be adjusted to be within the above range. The viscosities of both the first gypsum slurry and the second gypsum slurry can be in the above range.

Further, the content of the magnetic material may be different between the first gypsum slurry and the second gypsum slurry. Specifically, for example, the gypsum slurry can be prepared so that the content of the magnetic material in the first gypsum slurry is higher than that in the second gypsum slurry. With such a configuration, it is possible to more reliably obtain a gypsum-containing plate in which the content of the magnetic material in the first end region is larger than the content of the magnetic material in the central region of the gypsum core. However, when the content of the magnetic material in the first end region is larger than the content of the magnetic material in the second end region, for example, the first gypsum slurry supplied to the surface cover base paper 31 side. It can also be configured such that the content of the magnetic material is greater than the content of the magnetic material in the second gypsum slurry. In this case, the magnetic material may not be added to the first gypsum slurry supplied to the back cover base paper 36 side, or the content of the magnetic material may be the same as that of the second gypsum slurry.

The form is not limited to the use of the first gypsum slurry and the second gypsum slurry. For example, one type of gypsum slurry is produced and supplied onto a board base paper. Is also good.

Here, a configuration example of a kneading step, a molding step, a magnetic material uneven distribution step, and a hardening step in manufacturing gypsum board will be described with reference to FIG. Since the explanations have already been given in the first and second configuration examples, some duplicate explanations will be omitted.

In the method for producing a gypsum-containing plate of this configuration example, a gypsum slurry can be produced by kneading gypsum, which is a raw material of gypsum slurry, water, a magnetic material, and in some cases, various additives in the mixer 32. (Kneading process). At this time, as described above, the ratio of each component can be adjusted so that the viscosity of the gypsum slurry is within the range described above.

Then, the obtained first gypsum slurry 33 is passed through the delivery pipes 323 and 324 on the front cover base paper (board base paper) 31 and the back cover base paper (board base paper) 36 on the upstream side in the transport direction of the roll coater 35. Supply to. It can also be used in combination with the method of the first configuration example. Specifically, the magnetic material may be arranged in advance on either one or both of the surface 31A on the side of the front cover base paper 31 in contact with the gypsum slurry and the surface 36A of the back cover base paper 36 on the side in contact with the gypsum slurry. it can. Further, as described above, it can be added to the first gypsum slurry so that the content of the magnetic material per unit volume is larger than that of the second gypsum slurry.

The first gypsum slurry 33 on the front cover base paper 31 and the back cover base paper 36 each reaches the extension portion of the roll coater 35 and is extended at the extension portion. A thin layer of the first gypsum slurry 33 is formed on the surface cover base paper 31. Similarly, a thin layer of the first gypsum slurry 33 is formed on the back cover base paper 36.

The front cover base paper 31 is conveyed as it is, and the back cover base paper 36 is turned in the direction of the transfer line of the front cover base paper 31 by the turning roller 38. Then, both the front cover base paper 31 and the back cover base paper 36 are conveyed in the same direction and reach the molding machine 39. Here, the second gypsum slurry 34 is supplied from the mixer 32 through the pipe line 326 between the thin layers formed on the front cover base paper 31 and the back cover base paper 36.

Then, it can be molded by the molding machine 39 to form the molded body 391 (molding step). Next, the magnetic material uneven distribution step of transporting the magnets 392A and 392B on the transport path arranged so as to face at least one surface of the molded body 391 which is the molded body of the gypsum slurry can be carried out.

As described above, a magnetic material is added to the gypsum slurry contained in the molded product. By arranging the magnets 392A and 392B on the transport path of the molded body 391 so as to face at least one surface of the molded body, the magnetic material in the molded body 391 faces the magnets 392A and 392B. It will be drawn to the side of the surface. Therefore, the gypsum core can be a gypsum-containing plate in which the content of the magnetic material in the first end region is larger than the content of the magnetic material in the central region. In FIG. 3, one of the molded bodies 391 is formed. An example is shown in which the magnets 392A and 392B are provided so as to face the surface 391A and the other surface 391B. For example, when the magnetic material is unevenly distributed only on the first end region side, only the magnet 392A is used. It can also be provided.

The types of magnets 392A and 392B are not particularly limited, and either permanent magnets or electromagnets can be used. However, since it is possible to easily switch between a magnetized state and an unmagnetized state, an electromagnet is used. Is preferable.

Note that FIG. 3 shows an example in which one magnet 392A is provided on one surface 391A side of the molded body along the transport direction of the molded body 391, but the present invention is not limited to this form and the molded body is not limited to this. It is also possible to arrange two or more magnets along the transport direction of 391.

Further, the magnetic material uneven distribution step can also be carried out before the molding step. For example, as shown in FIG. 3, a case where a gypsum slurry containing a first gypsum slurry 33 and a second gypsum slurry 34 is molded on the upstream side of the molding machine 39 in the transport direction of the gypsum slurry to obtain a molded body 391. The magnet 392A'and the magnet 392B' can be arranged so as to face at least one surface 391A and, if necessary, the other surface 391B. By transporting the gypsum slurry on the transport path in which the magnets 392A'and 392B' are arranged, the magnetic material contained in the gypsum slurry is attracted to the surface side facing the magnets 392A'and 392B'. It will be. Then, since the gypsum slurry in a state where the magnetic material is unevenly distributed is introduced into the molding machine 39, the content of the magnetic material in the first end region of the gypsum core is the content of the magnetic material in the central region. The gypsum-containing plate can be larger than the amount.

Although FIG. 3 shows an example in which magnets 392A'and 392B' are provided, for example, when the magnetic material is unevenly distributed only on the first end region side, only magnets 392A'can be provided.

The types of magnets 392A'and 392B' are not particularly limited, and either permanent magnets or electromagnets can be used, but the magnetized state and the non-magnetized state can be easily switched. , It is preferable to use an electromagnet.

FIG. 3 shows an example in which one magnet 392A'is provided on one surface 391A side of the molded body 391 when the gypsum slurry is molded along the transport direction of the gypsum slurry, but the form is limited to this. Instead, two or more magnets can be arranged on the same side of the gypsum slurry along the transport direction of the gypsum slurry.

In addition to the magnets 392A and 392B described above, magnets 392A'and 392B' can also be provided. That is, the magnetic material uneven distribution step can be carried out before and after the molding step.

After the step of uneven distribution of the magnetic material, a hardening step of hydrating and hardening the gypsum slurry can be carried out in the process of transporting.

The hardening step can be carried out by allowing acicular crystals of dihydrate gypsum to be formed by a hydration reaction of the baked gypsum (hemihydrate gypsum) in the gypsum slurry to condense and solidify. Therefore, the hardening step can be carried out by reacting between the gypsum contained in the gypsum slurry and water in the molded body formed in the molding step and the hydration reaction of the gypsum progresses.

The setting time of the gypsum slurry is not particularly limited, but when the viscosity of the gypsum slurry is adjusted in the kneading step as in the case of the second configuration example, for example, gypsum is used as in the case of the second configuration example. The setting time of the slurry (cured product) can be 30 seconds or more and 180 seconds or less.

Since the curing reaction gradually progresses even while the magnetic material uneven distribution step is being carried out and it is difficult to strictly distinguish between the two, the magnetic material uneven distribution step and the curing step described above are used. Can also be carried out at the same time.

Here, gypsum board has been described as an example, but the base paper for board, which is the surface material, is changed to glass fiber non-woven fabric (glass tissue), glass mat, etc., and this is arranged so as to be buried in or near the surface. It is also possible to manufacture various gypsum-containing plates.

After the curing step, various arbitrary steps described in the first configuration example can also be carried out.

According to the method for producing a gypsum-containing plate of the present embodiment described above, by carrying out the magnetic material uneven distribution step, the magnetic material can be attracted and moved by the magnetic force from the magnet in the molded body, and the gypsum The core can be a gypsum-containing plate in which the content of the magnetic material in the first end region is higher than the content of the magnetic material in the central region.
[Magnetic joint treatment material]
Next, a configuration example of the magnetic joint treatment material of the present embodiment will be described.

By using the above-mentioned gypsum-containing plate, it is possible to form a wall or the like capable of adsorbing a magnetic material such as a magnet. However, when the wall or the like is formed by the gypsum-containing plate, the magnet is formed at the boundary between the gypsum-containing plates. There may be a part where the adsorption force is weakened.

Therefore, by performing the joint treatment between the gypsum-containing plates using the magnetic joint treatment material of the present embodiment, it is possible to prevent a portion where the attractive force of the magnet is weakened at the boundary between the gypsum-containing plates.

The magnetic joint treatment material of the present embodiment contains, for example, iron powder and a binder, and the content of the iron powder can be 2.0 g / cm ³ or more.

This means that when the iron powder content of the magnetic joint treatment material of the present embodiment is 2.0 g / cm ³ or more, it can be said that sufficient iron powder is contained, and it is sufficient when the joint treatment material is solidified. This is because it shows the attractive force of a magnet and is preferable. In particular, from the viewpoint of increasing the attractive force of the magnet, the iron powder content of the magnetic joint treatment material of the present embodiment is more preferably 2.5 g / cm ³ or more.

The upper limit of the iron powder content of the magnetic joint treatment material of the present embodiment is not particularly limited, but from the viewpoint of ensuring the properties of the joint treatment material, it may be, for example, 5.0 g / cm ³ or less. preferable.

The iron powder used for the magnetic joint treatment material of the present embodiment is not particularly limited, but it is preferable that the iron powder contains at least one selected from iron oxide powder, reduced iron powder, and atomized iron powder. The magnetic joint treatment material is usually supplied in a fluid state, and reactions such as oxidation easily proceed with the binder and other additives. Therefore, from the viewpoint of stabilizing the quality of iron powder, iron powder is oxidized. It is more preferably iron powder. The iron oxide powder is not particularly limited, but triiron tetroxide can be preferably used.

In addition, the magnetic joint treatment material of the present embodiment may also contain any other component. The magnetic joint treatment material of the present embodiment may contain, for example, a rust preventive. When the magnetic joint treatment material contains a rust preventive, it is possible to prevent the iron powder contained in the magnetic joint treatment material from being oxidized and discolored or the attractive force of the magnet being changed. ..

When the magnetic joint treatment material further contains a rust preventive, the magnetic joint treatment material preferably further contains the rust preventive in a proportion of 0.1% by mass or more with respect to the iron powder, preferably 0.3% by mass. It is more preferable to contain it in the above ratio.

When the magnetic joint treatment material of the present embodiment contains a rust preventive, the upper limit of the content is not particularly limited, but even if it is added excessively, the rust preventive effect does not change significantly, and the rust preventive effect does not change significantly. In consideration of the production cost, the rust inhibitor is preferably contained in a proportion of 20% by mass or less with respect to iron powder, for example.

The type of rust inhibitor is not particularly limited, but the rust inhibitor is, for example, a water-soluble or emulsion organic acid-based rust inhibitor, chelate-based rust inhibitor, organic acid amine-based rust inhibitor, fatty acid-based rust inhibitor. It is preferable to contain one or more selected from rust agents and nitrite-based rust preventives.

The magnetic joint treatment material may also contain any other additive, for example, a pigment for adjusting the color of the magnetic joint treatment material.

According to the magnetic joint treatment material of the present embodiment, since iron powder is contained, the magnet is attracted between a plurality of gypsum-containing plates constituting a wall or the like by using it when performing joint treatment between gypsum-containing plates. It is possible to suppress the decrease in force.

Specific examples will be described below, but the present invention is not limited to these examples.
[Experimental Example 1]
A gypsum board was manufactured using the apparatus shown in FIG. 3, and the content of the magnetic material contained in the gypsum board was evaluated. Experimental Example 1 is an example.

The procedure for producing gypsum board will be described with reference to FIG.

First, the manufacturing procedure of gypsum board will be described.

The surface cover base paper (board base paper) 31 is continuously conveyed along the production line from the right side to the left side in FIG. In this experimental example, the board base paper used was 200 g / m ² for both the front cover base paper 31 and the back cover base paper 36 described later.

In a single mixer 32, the composition is 1 part by mass of the coagulation adjuster, 0.3 part by mass of the water reducing agent, 0.5 part by mass of the adhesiveness improver, and 80 parts by mass of water with respect to 100 parts by mass of the gypsum. Gypsum slurry (gypsum mud) was prepared by kneading (kneading step).

Then, the gypsum slurry obtained in the mixer 32 was supplied onto the front cover base paper 31 and the back cover base paper 36 on the upstream side in the transport direction of the roll coater 35 through the distribution ports 321 and 322 and the delivery pipes 323 and 324.

At this time, with respect to the gypsum slurry taken out from the distribution port 322, 80 parts by mass of water atomized iron powder having an average particle diameter of 70 μm was added to 100 parts by mass of the gypsum added when preparing the gypsum slurry. It was added and mixed so as to be. On the surface cover base paper 31, the first gypsum slurry 33 to which the water-atomized iron powder was added was supplied.

The average particle size of the water atomized iron powder was evaluated using a laser diffraction type particle size distribution measuring device (trade name: Microtrack HRA manufactured by Nikkiso Co., Ltd.).

The first gypsum slurry 33 on the front cover base paper 31 and the back cover base paper 36 each reaches the extension portion of the roll coater 35 and is extended at the extension portion. A thin layer of the first gypsum slurry 33 is formed on the entire surface of the surface cover base paper 31. A plurality of engraved lines parallel to the transport direction are provided in advance on the surface cover base paper 31 near the end portion in the width direction thereof, and in the vicinity of the molding machine 39 described later, both side edge portions of the surface cover base paper 31 are engraved. It is bent along the line and extends upward and then inward. Specifically, the surface cover base paper 31 is bent along the above-mentioned engraved lines so as to cover a part of the side surface and the upper surface of the second gypsum slurry 34, which will be described later.

Similarly, a thin layer of the first gypsum slurry 33 is formed on the back cover base paper 36. The back cover base paper 36 is not foldable unlike the front cover base paper 31.

The front cover base paper 31 is conveyed as it is, and the back cover base paper 36 is turned in the direction of the transfer line of the front cover base paper 31 by the turning roller 38.

Then, both the front cover base paper 31 and the back cover base paper 36 are conveyed in the same direction and reach the molding machine 39. Here, the second gypsum slurry 34 is supplied through the pipe line 326 between the thin layer formed on the front cover base paper 31 and the back cover base paper 36.

At the preparative port 325, foam was added to the gypsum core. Further, the foam was produced by foaming a foaming agent (main component: alkyl ether sulfate), and by passing through the molding machine 39, a first first was formed between the front cover base paper 31 and the back cover base paper 36. A continuous laminate in which the layers formed by the gypsum slurry 33 and the second gypsum slurry 34 are arranged is formed. At this time, the gypsum board was molded so as to have a thickness of 12.5 mm (molding step).

The obtained molded product was cured in the process of being conveyed (curing step). Then, as it hardens, it leads to a rough cutting cutter (not shown). The rough cutting cutter cuts a continuous laminate into plate-like bodies of a predetermined length to form a plate-like body composed of a core material mainly composed of gypsum covered with base paper, that is, a semi-finished product of gypsum board. Will be done.

The coarsely cut laminate was further passed through a dryer (not shown) and forcibly dried to remove excess water (drying step). Then, a gypsum board was manufactured by cutting into a product having a predetermined length.

Surface cover of the obtained gypsum board When one surface, which is the main surface on the base paper side, was erected so as to be perpendicular to the ground and a magnet was attracted to the one surface, the magnet did not come off and the obtained gypsum board was obtained. It was confirmed that the magnet was attracted.

The gypsum board obtained in this experimental example has a content of water atomized iron powder, which is a magnetic material, per unit area of 1.0 kg / m ² . Here, it means the content of the magnetic material per unit area on one surface 11 (see FIG. 1), which is the main surface on the surface cover base paper 31 side of the gypsum board.

With respect to the obtained gypsum board, the base paper for gypsum board on both surfaces of the gypsum board was peeled off to make only the gypsum core. Then, along the thickness direction of the gypsum core, from one surface side to the other surface side, three regions of equal thickness, a first end region, a central region, and a second end region, are formed. It was divided into two parts, and each region was pulverized.

The obtained powder of each region is placed in a 635 mesh sieve having a smaller opening than the particle size of the magnetic material used, and washed with water to wash away the gypsum component, and the magnetic material contained in each region is taken out. It was. Table 1 shows the content ratio (percentage) of the magnetic material in each region calculated from the mass of the magnetic material in each region.

表１に示した結果によると、第１の端部領域のみに磁性材料が含まれていることを確認できた。このため、磁性材料の使用量を抑制し、石膏ボード全体の重さやコストを抑制しつつも、マグネットを吸着することができる石膏ボードを得ることができた。
［実験例２］
図３に示した装置を用いて石膏ボードを製造し、該石膏ボード中に含まれる磁性材料の含有量について評価を行った。実験例２は実施例となる。

According to the results shown in Table 1, it was confirmed that the magnetic material was contained only in the first end region. For this reason, it was possible to obtain a gypsum board capable of attracting magnets while suppressing the amount of magnetic material used and suppressing the weight and cost of the entire gypsum board.
[Experimental Example 2]
A gypsum board was manufactured using the apparatus shown in FIG. 3, and the content of the magnetic material contained in the gypsum board was evaluated. Experimental Example 2 is an example.

The procedure for producing gypsum board will be described with reference to FIG.

First, the manufacturing procedure of gypsum board will be described.

The surface cover base paper (board base paper) 31 is continuously conveyed along the production line from the right side to the left side in FIG. In this experimental example, the board base paper used was 200 g / m ² for both the front cover base paper 31 and the back cover base paper 36 described later.

In a single mixer 32, 80 parts by mass of the same water atomizing iron powder as in Experimental Example 1, 1 part by mass of a coagulation adjuster, 0.3 parts by mass of a water reducing agent, and 0 parts of an adhesiveness improver with respect to 100 parts by mass of gypsum. A gypsum slurry (gypsum slurry) was prepared by kneading so as to have a composition of .5 parts by mass and 80 parts by mass of water (kneading step). As described above, a water reducing agent is added to the gypsum slurry so as to be 0.3 parts by mass with respect to 100 parts by mass of the gypsum, and the coagulation adjusting agent is obtained so that the viscosity of the obtained gypsum slurry is 50 cps. Was added so as to be 1 part by mass with respect to 100 parts by mass of gypsum, and the setting time of the obtained gypsum slurry was adjusted to 60 seconds.

The viscosity of the gypsum slurry was measured with a Brookfield viscometer (manufactured by Rion Co., Ltd., product name VT04). Specifically, the gypsum slurry immediately after being discharged from the pipe line 326 of the mixer 32 in FIG. 3 was scooped with a container, and it was confirmed that the viscosity of the gypsum slurry immediately after scooping was the above value. The setting time of the gypsum slurry means the starting time in the setting time specified in JIS R 9112 (2015), and the gypsum slurry was measured and confirmed by the following procedure.
First, a cylindrical mold having an inner diameter of 78 ± 5 mm and a height of 40.0 ± 0.5 mm was placed on a glass plate, and the prepared gypsum slurry was poured into the glass plate. Next, a metal needle having a length of 45 mm and a diameter of 2 mm and having its head cut flat is placed in the center of the gypsum slurry so as to be perpendicular to the glass plate and the flat cut side is located in the gypsum slurry. did. Then, the time from when the gypsum and water come into contact with each other to prepare the gypsum slurry until the metal needle stops at a height of about 1 mm from the bottom surface of the gypsum slurry specimen placed in the cylindrical shape. It was measured and used as the setting time (first train time). The metal needle used had a total mass of 300 ± 1 g of the movable part that descended when the flatly cut side was arranged in the gypsum slurry.

Then, the gypsum slurry obtained in the mixer 32 was supplied onto the front cover base paper 31 and the back cover base paper 36 on the upstream side in the transport direction of the roll coater 35 through the distribution ports 321 and 322 and the delivery pipes 323 and 324.

The first gypsum slurry 33 on the front cover base paper 31 and the back cover base paper 36 each reaches the extension portion of the roll coater 35 and is extended at the extension portion. A thin layer of the first gypsum slurry 33 is formed on the entire surface of the surface cover base paper 31. A plurality of engraved lines parallel to the transport direction are provided in advance on the surface cover base paper 31 near the end portion in the width direction thereof, and in the vicinity of the molding machine 39 described later, both side edge portions of the surface cover base paper 31 are engraved. It is bent along the line and extends upward and then inward. Specifically, the surface cover base paper 31 is bent along the above-mentioned engraved lines so as to cover a part of the side surface and the upper surface of the second gypsum slurry 34, which will be described later.

Similarly, a thin layer of the first gypsum slurry 33 is formed on the back cover base paper 36. The back cover base paper 36 is not foldable unlike the front cover base paper 31.

The front cover base paper 31 is conveyed as it is, and the back cover base paper 36 is turned in the direction of the transfer line of the front cover base paper 31 by the turning roller 38.

Then, both the front cover base paper 31 and the back cover base paper 36 are conveyed in the same direction and reach the molding machine 39. Here, the second gypsum slurry 34 is supplied through the pipe line 326 between the thin layer formed on the front cover base paper 31 and the back cover base paper 36.

At the preparative port 325, foam was added to the gypsum core. Further, the foam was produced by foaming a foaming agent (main component: alkyl ether sulfate), and by passing through the molding machine 39, the first surface cover base paper 31 and the back cover base paper 36 were first. A continuous laminate in which the layers formed by the gypsum slurry 33 and the second gypsum slurry 34 are arranged is formed. At this time, the gypsum board was molded so as to have a thickness of 12.5 mm (molding step).

The obtained molded product was cured in the process of being conveyed (curing step). Then, as it hardens, it leads to a rough cutting cutter (not shown). The rough cutting cutter cuts a continuous laminate into plate-like bodies of a predetermined length to form a plate-like body composed of a core material mainly composed of gypsum covered with base paper, that is, a semi-finished product of gypsum board. Will be done.

The coarsely cut laminate was further passed through a dryer (not shown) and forcibly dried to remove excess water (drying step). Then, a gypsum board was manufactured by cutting into a product having a predetermined length.

Surface cover of the obtained gypsum board When one surface, which is the main surface on the base paper side, was erected so as to be perpendicular to the ground and a magnet was attracted to the one surface, the magnet did not come off and the obtained gypsum board was obtained. It was confirmed that the magnet was attracted.

The gypsum board obtained in this experimental example has a content of water atomized iron powder, which is a magnetic material, per unit area of 1.0 kg / m ² . Here, it means the content of the magnetic material per unit area on one surface 11 (see FIG. 1), which is the main surface on the surface cover base paper 31 side of the gypsum board.

With respect to the obtained gypsum board, the base paper for gypsum board on both surfaces of the gypsum board was peeled off to make only the gypsum core. Then, along the thickness direction of the gypsum core, from one surface side to the other surface side, three regions of equal thickness, a first end region, a central region, and a second end region, are formed. It was divided into two parts, and each region was pulverized.

The obtained powder of each region is placed in a 635 mesh sieve having a smaller opening than the particle size of the magnetic material used, and washed with water to wash away the gypsum component, and the magnetic material contained in each region is taken out. It was. Table 1 shows the content ratio (percentage) of the magnetic material in each region calculated from the mass of the magnetic material in each region.

According to the results shown in Table 1, it was confirmed that the content ratio of the magnetic material in the first end region was higher than that in the other regions.
[Experimental Example 3]
A gypsum board was manufactured using the apparatus shown in FIG. 3, and the content of the magnetic material contained in the gypsum board was evaluated. Experimental Example 3 is an example.

The procedure for producing gypsum board will be described with reference to FIG.

First, the manufacturing procedure of gypsum board will be described.

The surface cover base paper (board base paper) 31 is continuously conveyed along the production line from the right side to the left side in FIG. In this experimental example, the board base paper used was 200 g / m ² for both the front cover base paper 31 and the back cover base paper 36 described later.

In a single mixer 32, 80 parts by mass of the same water atomizing iron powder as in Experimental Example 1, 1 part by mass of a coagulation adjuster, 0.3 parts by mass of a water reducing agent, and 0 parts of an adhesiveness improver with respect to 100 parts by mass of gypsum. A gypsum slurry (gypsum slurry) was prepared by kneading so as to have a composition of .5 parts by mass and 80 parts by mass of water (kneading step).

Then, the gypsum slurry obtained in the mixer 32 was supplied onto the front cover base paper 31 and the back cover base paper 36 on the upstream side in the transport direction of the roll coater 35 through the distribution ports 321 and 322 and the delivery pipes 323 and 324.

The first gypsum slurry 33 on the front cover base paper 31 and the back cover base paper 36 each reaches the extension portion of the roll coater 35 and is extended at the extension portion. A thin layer of the first gypsum slurry 33 is formed on the entire surface of the surface cover base paper 31. A plurality of engraved lines parallel to the transport direction are provided in advance on the surface cover base paper 31 near the end portion in the width direction thereof, and in the vicinity of the molding machine 39 described later, both side edge portions of the surface cover base paper 31 are engraved. It is bent along the line and extends upward and then inward. Specifically, the surface cover base paper 31 is bent along the above-mentioned engraved lines so as to cover a part of the side surface and the upper surface of the second gypsum slurry 34, which will be described later.

Similarly, a thin layer of the first gypsum slurry 33 is formed on the back cover base paper 36. The back cover base paper 36 is not foldable unlike the front cover base paper 31.

The front cover base paper 31 is conveyed as it is, and the back cover base paper 36 is turned in the direction of the transfer line of the front cover base paper 31 by the turning roller 38.

Then, both the front cover base paper 31 and the back cover base paper 36 are conveyed in the same direction and reach the molding machine 39. Here, the second gypsum slurry 34 is supplied through the pipe line 326 between the thin layer formed on the front cover base paper 31 and the back cover base paper 36.

At the preparative port 325, foam was added to the gypsum core. Further, the foam was produced by foaming a foaming agent (main component: alkyl ether sulfate), and by passing through the molding machine 39, a first first was formed between the front cover base paper 31 and the back cover base paper 36. A continuous laminate in which the layers formed by the gypsum slurry 33 and the second gypsum slurry 34 are arranged is formed. At this time, the gypsum board was molded so as to have a thickness of 12.5 mm (molding step).

Electric power was supplied to the magnet 392A arranged as shown in FIG. 3 on the transport path of the obtained molded product to magnetize it. As a result, the molded product obtained by molding the gypsum slurry was transported on the transport path in which the magnet 392A was arranged so as to face one surface of the molded body, that is, the surface on the surface cover base paper 31 side (magnetic material uneven distribution). Process)
The obtained molded product was cured in the process of being conveyed (curing step). Then, as it hardens, it leads to a rough cutting cutter (not shown). The rough cutting cutter cuts a continuous laminate into plate-like bodies of a predetermined length to form a plate-like body composed of a core material mainly composed of gypsum covered with base paper, that is, a semi-finished product of gypsum board. Will be done.

The coarsely cut laminate was further passed through a dryer (not shown) and forcibly dried to remove excess water (drying step). Then, a gypsum board was manufactured by cutting into a product having a predetermined length.

Surface cover of the obtained gypsum board When one surface, which is the main surface on the base paper side, was erected so as to be perpendicular to the ground and a magnet was attracted to the one surface, the magnet did not come off and the obtained gypsum board was obtained. It was confirmed that the magnet was attracted.

The gypsum board obtained in this experimental example has a content of water atomized iron powder, which is a magnetic material, per unit area of 1.0 kg / m ² . Here, it means the content of the magnetic material per unit area on one surface 11 (see FIG. 1), which is the main surface on the surface cover base paper 31 side of the gypsum board.

With respect to the obtained gypsum board, the base paper for gypsum board on both surfaces of the gypsum board was peeled off to make only the gypsum core. Then, along the thickness direction of the gypsum core, from one surface side to the other surface side, three regions of equal thickness, a first end region, a central region, and a second end region, are formed. It was divided into two parts, and each region was pulverized.

The obtained powder of each region is placed in a 635 mesh sieve having a smaller opening than the particle size of the magnetic material used, and washed with water to wash away the gypsum component, and the magnetic material contained in each region is taken out. It was. Table 1 shows the content ratio (percentage) of the magnetic material in each region calculated from the mass of the magnetic material in each region.

According to the results shown in Table 1, it was confirmed that the content ratio of the magnetic material in the first end region was higher than that in the other regions.
[Experimental Examples 4-1 to 4-6]
When preparing the gypsum slurry, reduced iron powder having an average particle diameter of 70 μm was used instead of water atomized iron powder, and the content per unit area of the magnetic material was set to the value shown in Table 2 for each experimental example. In addition, gypsum board was produced in the same manner as in Experimental Example 3 except that the amount of reduced iron powder added was adjusted. The content of the magnetic material per unit area means the content of the magnetic material per unit area on one surface 11 (see FIG. 1), which is the main surface of the gypsum board on the surface cover base paper 31 side. To do. The same applies to the following other experimental examples.

Experimental Examples 4-1 to 4-6 are examples.

A test sample having a width of 300 mm and a length of 400 mm was cut out from the central portion of the obtained gypsum board and subjected to the following magnet adsorption test.

In the magnet adsorption test, as shown in FIG. 2, first, the gypsum-containing plate 21 produced in each experimental example, that is, the gypsum board is erected so that one surface 21a, which is the main surface on the surface cover base paper side, is vertical. Then, one magnet 22 having a diameter of the magnet portion of 17 mmφ and an attraction force to the 1 mm iron plate of 3.5 N was used, and the A4 paper 23 was attached to one surface 21a by the magnet. Then, the number of sheets of A4 paper 23 was increased until the A4 paper 23 fell, and the number of sheets when the A4 paper 23 fell-1 was evaluated as the magnet attraction force of the gypsum board.

As for the magnet used in the magnet adsorption test, as shown in FIG. 4, the magnet 41 is attracted to an iron plate 42 having a thickness of 1 mm, and the hook 411 connected to the magnet 41 is 3 mm by an autograph (not shown). The maximum intensity was measured by pulling up along the block arrow A at a speed of / sec. Then, the maximum strength was set as the attraction force to the iron plate to 1 mm, and the same magnet was used in this experimental example.

Further, when the magnet adsorption test shown in FIG. 2 is carried out, the distance L between the center of the magnet 22 and the upper end of the A4 paper 23 is 3 cm, and the center of the magnet 22 is in the width direction of the A4 paper 23. The magnet was placed so that it was located in the center.

Then, as the A4 paper 23, A4 paper having a thickness of 0.09 mm and a mass of 64 g / m ² was used.

The evaluation results are shown in Table 2.

Further, with respect to the obtained gypsum board of each experimental example, after the completion of the magnet adsorption test, the gypsum board base papers on both surfaces of the gypsum board were peeled off in the same manner as in Experimental Example 3, and only the gypsum core was used. Then, along the thickness direction of the gypsum core, from one surface side to the other surface side, three regions of equal thickness, a first end region, a central region, and a second end region, are formed. It was divided into two parts, and each region was pulverized.

The obtained powder of each region is placed in a 635 mesh sieve having a smaller opening than the particle size of the magnetic material used, and washed with water to wash away the gypsum component, and the magnetic material contained in each region is taken out. It was. When the content ratio (percentage) of the magnetic material in each region was calculated from the mass of the magnetic material in each region, it was confirmed that the content ratio of the magnetic material in the first end region was higher than that in the other regions. did it.
[Experimental Examples 5-1 to 5-6]
Experimental Example 3 except that the amount of water atomized iron powder added was adjusted so that the content of the magnetic material per unit area of the gypsum slurry was the value shown in Table 2 for each Experimental Example. A gypsum board was manufactured in the same manner as above.

Experimental Examples 5-1 to 5-6 are examples.

A test sample having a width of 300 mm and a length of 400 mm was cut out from the central portion of the obtained gypsum board, and a magnet adsorption test was carried out in the same manner as in Experimental Examples 4-1 to 4-6.

The evaluation results are shown in Table 2.

Further, with respect to the obtained gypsum board of each experimental example, after the completion of the magnet adsorption test, the gypsum board base papers on both surfaces of the gypsum board were peeled off in the same manner as in Experimental Example 3, and only the gypsum core was used. Then, along the thickness direction of the gypsum core, from one surface side to the other surface side, three regions of equal thickness, a first end region, a central region, and a second end region, are formed. It was divided into two parts, and each region was pulverized.

The obtained powder of each region is placed in a 635 mesh sieve having a smaller opening than the particle size of the magnetic material used, and washed with water to wash away the gypsum component, and the magnetic material contained in each region is taken out. It was. When the content ratio (percentage) of the magnetic material in each region was calculated from the mass of the magnetic material in each region, it was confirmed that the content ratio of the magnetic material in the first end region was higher than that in the other regions. did it.
[Experimental Examples 6-1 to 6-6]
When preparing the gypsum slurry, iron oxide powder having an average particle diameter of 70 μm was used instead of water atomized iron powder, and the content of the magnetic material per unit area was the value shown in Table 2 for each experimental example. A gypsum board was produced in the same manner as in Experimental Example 2 except that the amount of water atomized iron powder added was adjusted so as to be. As iron oxide, triiron tetroxide was used.

Experimental Examples 6-1 to 6-6 are examples.

A test sample having a width of 300 mm and a length of 400 mm was cut out from the central portion of the obtained gypsum board, and a magnet adsorption test was carried out in the same manner as in Experimental Examples 4-1 to 4-6.

The evaluation results are shown in Table 2.

Further, with respect to the obtained gypsum board of each experimental example, after the completion of the magnet adsorption test, the gypsum board base papers on both surfaces of the gypsum board were peeled off in the same manner as in Experimental Example 3, and only the gypsum core was used. Then, along the thickness direction of the gypsum core, from one surface side to the other surface side, three regions of equal thickness, a first end region, a central region, and a second end region, are formed. It was divided into two parts, and each region was pulverized.

The obtained powder of each region is placed in a 635 mesh sieve having a smaller opening than the particle size of the magnetic material used, and washed with water to wash away the gypsum component, and the magnetic material contained in each region is taken out. It was. When the content ratio (percentage) of the magnetic material in each region was calculated from the mass of the magnetic material in each region, it was confirmed that the content ratio of the magnetic material in the first end region was higher than that in the other regions. did it.
[Experimental Examples 7-1 to 7-6]
When preparing the gypsum slurry, iron oxide powder having an average particle diameter of 70 μm was used instead of water atomized iron powder, and the content of the magnetic material per unit area was the value shown in Table 2 for each experimental example. A gypsum board was produced in the same manner as in Experimental Example 3 except that the amount of water atomized iron powder added was adjusted so as to be. As iron oxide, triiron tetroxide was used.

Experimental Examples 7-1 to 7-6 are examples.

A test sample having a width of 300 mm and a length of 400 mm was cut out from the central portion of the obtained gypsum board, and a magnet adsorption test was carried out in the same manner as in Experimental Examples 4-1 to 4-6.

The evaluation results are shown in Table 2.

Further, with respect to the obtained gypsum board of each experimental example, after the completion of the magnet adsorption test, the gypsum board base papers on both surfaces of the gypsum board were peeled off in the same manner as in Experimental Example 3, and only the gypsum core was used. Then, along the thickness direction of the gypsum core, from one surface side to the other surface side, three regions of equal thickness, a first end region, a central region, and a second end region, are formed. It was divided into two parts, and each region was pulverized.

The obtained powder of each region is placed in a 635 mesh sieve having a smaller opening than the particle size of the magnetic material used, and washed with water to wash away the gypsum component, and the magnetic material contained in each region is taken out. It was. When the content ratio (percentage) of the magnetic material in each region was calculated from the mass of the magnetic material in each region, it was confirmed that the content ratio of the magnetic material in the first end region was higher than that in the other regions. did it.

［実験例８−１〜実験例８−６］
石膏スラリーを調製する際、水アトマイズ鉄粉に替えて平均粒子径が７０μｍの還元鉄粉を用い、磁性材料の単位面積当たりの含有量が、各実験例について表３に示した値となるように、還元鉄粉の添加量を調整した点以外は、実験例１と同様にして石膏ボードを製造した。

[Experimental Examples 8-1 to 8-6]
When preparing the gypsum slurry, reduced iron powder having an average particle size of 70 μm was used instead of water atomized iron powder, and the content per unit area of the magnetic material was set to the value shown in Table 3 for each experimental example. In addition, gypsum board was produced in the same manner as in Experimental Example 1 except that the amount of reduced iron powder added was adjusted.

Experimental Examples 8-1 to 8-6 are examples.

A test sample having a width of 300 mm and a length of 400 mm was cut out from the central portion of the obtained gypsum board, and a magnet adsorption test was carried out in the same manner as in Experimental Examples 4-1 to 4-6.

The evaluation results are shown in Table 3.

Further, with respect to the obtained gypsum board of each experimental example, after the completion of the magnet adsorption test, the gypsum board base papers on both surfaces of the gypsum board were peeled off in the same manner as in Experimental Example 3, and only the gypsum core was used. Then, along the thickness direction of the gypsum core, from one surface side to the other surface side, three regions of equal thickness, a first end region, a central region, and a second end region, are formed. It was divided into two parts, and each region was pulverized.

The obtained powder of each region is placed in a 635 mesh sieve having a smaller opening than the particle size of the magnetic material used, and washed with water to wash away the gypsum component, and the magnetic material contained in each region is taken out. It was. When the content ratio (percentage) of the magnetic material in each region was calculated from the mass of the magnetic material in each region, it was confirmed that the content ratio of the magnetic material in the first end region was higher than that in the other regions. did it.
[Experimental Examples 9-1 to 9-6]
The gypsum board was prepared in the same manner as in Experimental Example 1 except that the amount of water atomized iron powder added was adjusted so that the content of the magnetic material per unit area would be the value shown in Table 3 for each Experimental Example. Manufactured.

Experimental Examples 9-1 to 9-6 are examples.

A test sample having a width of 300 mm and a length of 400 mm was cut out from the central portion of the obtained gypsum board, and a magnet adsorption test was carried out in the same manner as in Experimental Examples 4-1 to 4-6.

The evaluation results are shown in Table 3.

Further, with respect to the obtained gypsum board of each experimental example, after the completion of the magnet adsorption test, the gypsum board base papers on both surfaces of the gypsum board were peeled off in the same manner as in Experimental Example 3, and only the gypsum core was used. Then, along the thickness direction of the gypsum core, from one surface side to the other surface side, three regions of equal thickness, a first end region, a central region, and a second end region, are formed. It was divided into two parts, and each region was pulverized.

The obtained powder of each region is placed in a 635 mesh sieve having a smaller opening than the particle size of the magnetic material used, and washed with water to wash away the gypsum component, and the magnetic material contained in each region is taken out. It was. When the content ratio (percentage) of the magnetic material in each region was calculated from the mass of the magnetic material in each region, it was confirmed that the content ratio of the magnetic material in the first end region was higher than that in the other regions. did it.
[Experimental Examples 10-1 to 10-6]
When preparing the gypsum slurry, iron oxide powder having an average particle diameter of 70 μm was used instead of water atomized iron powder, and the content of the magnetic material per unit area was the value shown in Table 3 for each experimental example. A gypsum board was produced in the same manner as in Experimental Example 1 except that the amount of water atomized iron powder added was adjusted so as to be. As iron oxide, triiron tetroxide was used.

Experimental Examples 10-1 to 10-6 are examples.

A test sample having a width of 300 mm and a length of 400 mm was cut out from the central portion of the obtained gypsum board, and a magnet adsorption test was carried out in the same manner as in Experimental Examples 4-1 to 4-6.

The evaluation results are shown in Table 3.

Further, with respect to the obtained gypsum board of each experimental example, after the completion of the magnet adsorption test, the gypsum board base papers on both surfaces of the gypsum board were peeled off in the same manner as in Experimental Example 3, and only the gypsum core was used. Then, along the thickness direction of the gypsum core, from one surface side to the other surface side, three regions of equal thickness, a first end region, a central region, and a second end region, are formed. It was divided into two parts, and each region was pulverized.

The obtained powder of each region is placed in a 635 mesh sieve having a smaller opening than the particle size of the magnetic material used, and washed with water to wash away the gypsum component, and the magnetic material contained in each region is taken out. It was. When the content ratio (percentage) of the magnetic material in each region was calculated from the mass of the magnetic material in each region, it was confirmed that the content ratio of the magnetic material in the first end region was higher than that in the other regions. did it.

以上に石膏含有板、石膏含有板の製造方法を、実施形態等で説明したが、本発明は上記実施形態等に限定されない。特許請求の範囲に記載された本発明の要旨の範囲内において、種々の変形、変更が可能である。

Although the gypsum-containing plate and the method for producing the gypsum-containing plate have been described above in the embodiments and the like, the present invention is not limited to the above-described embodiments and the like. Various modifications and changes are possible within the scope of the gist of the present invention described in the claims.

This application claims priority based on Japanese Patent Application No. 2017-212225 filed with the Japan Patent Office on November 1, 2017, and the entire contents of Japanese Patent Application No. 2017-212225 are included in this international application. Invite.

10 Gypsum cores 11, 21a One surface 12 The other surface 141 First end area 142 Central area 143 Second end area

Claims (7)

A gypsum-containing plate containing a gypsum core,
The gypsum core contains a magnetic material and gypsum.
The gypsum core is formed along the thickness direction from one surface side to the other surface side with three regions having the same thickness: a first end region, a central region, and a second end region. If you do
A gypsum-containing plate in which the content of the magnetic material in the first end region is higher than the content of the magnetic material in the central region. The gypsum-containing plate according to claim 1, wherein the content of the magnetic material in the first end region is higher than the content of the magnetic material in the second end region. The gypsum-containing plate according to claim 1 or 2, wherein the magnetic material present in the first end region is 35% by mass or more of the magnetic material contained in the gypsum core. The gypsum-containing plate according to any one of claims 1 to 3, wherein the magnetic material has a powder shape. A kneading step of kneading at least gypsum and a raw material containing water to form a gypsum slurry.
A molding process of molding the gypsum slurry to form a molded body,
It has a curing step of curing the molded product obtained in the molding step.
A method for producing a gypsum-containing plate in which a magnetic material is arranged on the surface side of the molded product in the molding step. A kneading step of kneading raw materials containing at least gypsum, water, and a magnetic material to form a gypsum slurry.
A molding process of molding the gypsum slurry to form a molded body,
It has a curing step of curing the molded product obtained in the molding step.
In the kneading step, the viscosity of the gypsum slurry was set to 5 cps or more and 100 cps or less.
A method for producing a gypsum-containing plate in which the setting time of the molded product is 30 seconds or more and 180 seconds or less. A kneading step of kneading raw materials containing at least gypsum, water, and a magnetic material to form a gypsum slurry.
A molding process of molding the gypsum slurry to form a molded body,
A magnetic material uneven distribution step of transporting the gypsum slurry on a transport path in which magnets are arranged so as to face at least one surface of the molded body.
A method for producing a gypsum-containing plate, comprising a curing step of curing the molded product after the uneven distribution step of the magnetic material.

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