JP3332451B2 - Inorganic base plate and method for producing the same - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an inorganic base plate used for a wall base, and more particularly to an inorganic base plate capable of reducing abrasion of a cutting blade of a cutter during cloth bonding and a method of manufacturing the same.

[0002]

2. Description of the Related Art Conventionally, since a gypsum board is heavy, an inorganic base plate which is reduced in weight is, for example, a surface layer of a middle layer made mainly of an inorganic foam and added with a fibrous material as a reinforcing material. It is considered that a surface layer portion and a back layer portion each made of a mineral fiber and an inorganic powder such as calcium carbonate are laminated and integrated on the back surface.

[0003]

However, in the above-mentioned inorganic base plate, the mineral fibers having the same hardness as the cutting edge of the cutter having a Mohs hardness of about 6 to 7 are exposed on the surface, so that the cloth is bonded with the cloth. When the overlapping part of the cloth is cut with a cutter at this time, the cutting edge of the cutter is easily worn, and the cutting work of about 30 cm starts to be caught. Therefore, the cutting edge of the cutter often needs to be replaced. There is a problem that the workability is poor when used as.

[0004]

SUMMARY OF THE INVENTION In view of the above problems, the present inventors provided a thin film layer made of pulp and inorganic powder on the surface of an inorganic base plate from which mineral fibers were exposed, and then cross-attached. Attention was paid to the fact that wear of the cutting blade of the cutter was reduced in this case, and based on this finding, the present invention was completed.

As shown in FIG. 1, the gist of the present invention is that at least one of a surface layer 2 and a back layer 3 made of mineral fibers and inorganic powders laminated on the front and back surfaces of a lightweight middle layer 1. The inorganic base plate 6 is characterized in that a thin film layer 4 (5) composed of pulp and an inorganic powder is laminated and integrated on the surface of the base plate.

[0006] In addition, as a method of manufacturing the inorganic base plate, a thin layer 4 (at least one surface of a laminate formed by laminating a surface layer portion 2 and a back layer portion 3 on the front and back surfaces of a middle layer portion 1) is formed. 5) may be laminated and manufactured, or
When laminating the surface layer 2 and the back layer 3 on the front and back surfaces of the middle layer 1 to form a laminate, there is a method of manufacturing by laminating the surface layer 2 in which at least the thin film layer 4 is integrally formed.

The material for forming the middle layer 1 is not particularly limited, but is preferably made of a lightweight inorganic material from the viewpoint of the transportability, workability and fire resistance of the inorganic base plate 6 to be manufactured. For example, mainly composed of inorganic foam,
It is preferable that a specific gravity of 0.5 or less obtained by adding an appropriate amount of a fibrous material and a binder thereto is used.

As the inorganic foam, for example, perlite or shirasu foam can be used for weight reduction.

Examples of the fibrous material include mineral fibers such as rock wool, mineral wool and glass fiber, pulp and other plant fibers, and synthetic fibers such as olefins.

The binder is added for binding and integrating the inorganic foam and the mineral fiber, and examples thereof include synthetic resins such as acrylic resins and phenol resins, and starch. In particular, since starch swells and has a sufficient bonding effect even in a small amount, it is very effective when producing lightweight non-combustible or semi-combustible materials.

These inorganic foams, fibrous materials and binders can all be arbitrarily selected, and can be used alone or in appropriate combination.

However, in order to obtain a desired fire protection property, that is, to obtain a quasi-incombustible material, it is necessary that both the organic fiber and the binder be 15% by weight or less of the whole. It is necessary that the total amount of the organic components is not more than 7% by weight of the whole.

The reason why the specific gravity of the middle layer portion 1 is set to 0.5 or less is that the surface layer portion 2 or the back layer portion 3 needs to have a high specific gravity in order to secure a predetermined strength and hardness. Part 1
When the specific gravity is 0.5 or more, it is difficult to reduce the weight of the inorganic base plate 6.

The surface layer 2 and the back layer 3 disposed on the front and back surfaces of the middle layer 1 or the middle layer forming layer to be the middle layer 1 are mainly composed of mineral fibers and inorganic powder, and are further combined with each other. It is composed of an appropriate amount of a binder added for integration, and organic fibers as a reinforcing material added as needed.

The mineral fibers used for the surface layer portion 2 and the back layer portion 3 can be arbitrarily selected from the mineral fibers used for forming the middle layer portion 1, but are different from those used for the middle layer portion 1 if necessary. Mineral fibers may be selected. The composition ratio of the mineral fibers in the surface layer 2 and the back layer 3 is 20.
Preferably it is ~ 80% by weight. If the amount is less than 20% by weight, the desired strength cannot be obtained unless the amount of the binder is increased. On the other hand, if the amount of the binder is increased, the fire resistance is reduced. Is relatively reduced, a desired surface hardness cannot be obtained, and the nail holding power is not sufficient.

The inorganic powder is added in order to increase the hardness and secure the screwing performance while maintaining the fire resistance, and for example, calcium carbonate, silica sand, micro silica, slag, aluminum hydroxide, etc. Is used. The average particle size of the inorganic powder may be 40 to 300 μm, and particularly, when the average particle size is about 100 μm, the strength of the surface layer portion 2 and the back layer portion 3 is maximized.

The materials and amounts of the binder and the organic fibers added for forming the surface layer 2 and the back layer 3 may be appropriately selected as needed, and are not particularly limited.

The specific gravity of the surface layer 2 and the back layer 3 must be 0.6 or more. When the specific gravity is less than 0.6, the dense surface layer portion 2 and the back layer portion 3 having desired hardness are formed.
Is not obtained.

The thin film layer 4 (5) formed on at least one surface of the surface layer portion 2 or the back layer portion 3 has a cutter suitability of the surface layer portion 2 or the back layer portion 3 laminated on the front and back surfaces of the middle layer portion 1. It is formed mainly of pulp and inorganic powder, and is formed by adding an appropriate amount of a binder.

The pulp is added in order to hold an inorganic powder described below, and examples thereof include wood pulp, recycled pulp, and synthetic pulp. The pulp composition ratio in the thin film layers 4 and 5 is preferably 20 to 60% by weight. If the content is less than 20% by weight, it is difficult to hold the inorganic powdery material, and the surface becomes powdery, and it becomes difficult to apply the adhesive.
This is because even if the thickness is a predetermined thickness, the fire resistance is reduced due to a large amount of organic components.

The inorganic powdery material is added mainly to secure the smoothness of the surface and to protect the cutting edge of the cutter, and examples thereof include calcium carbonate and aluminum hydroxide. In particular, when the inorganic powder is aluminum hydroxide, the powder itself is a crystallized powder having bound water, which is effective in fire prevention.
Also, since aluminum hydroxide is less powdery than calcium carbonate, it exhibits better adhesion when cross-attached.

The inorganic powder used here is preferably calcium carbonate or a material having a lower Mohs hardness than calcium carbonate. This is because if the Mohs hardness of the inorganic powder according to the present invention is higher than the Mohs hardness of calcium carbonate, the suitability for the cutter is worse than that of a commercially available gypsum board.

The binder is for binding and integrating the pulp and the inorganic powder. For example, starch or the like is used, and about 5% by weight of the composition ratio of the thin film layers 4 and 5 is added.

Further, the thickness of the thin film layers 4 and 5 is 0.05 to
It is preferably 0.4 mm. 0.05mm thick
If it is less than 1, the cutting edge of the cutter bites into the surface layer portion 2 or the back layer portion 3 and the suitability of the cutter cannot be improved, and if it exceeds 0.4 mm, the fire resistance decreases.

Next, a method for producing an inorganic base plate according to the present invention will be described. First, as a method of manufacturing a four-layer inorganic base plate, for example, as shown in FIG. 2, a mineral fiber, an inorganic powder, a binder, and an organic fiber are suspended in water to obtain an aqueous slurry. This is wet-processed to obtain a wet mat to be the back layer 3. Then, the mixture 7 obtained by mixing the inorganic foam, the fibrous material, and the binder is sprayed and deposited on the upper surface of the back layer 3 to form the middle layer forming layer 8 serving as the middle layer. Next, the surface layer portion 2 obtained in the same manner as the above-described back layer portion 3 is laminated on the upper surface of the intermediate layer portion forming layer 8 to form a laminate 9. Further, a pulp, an inorganic powder, a binder and a flocculant are put into water and mixed to obtain an aqueous slurry, and a wet sheet to be a thin film layer 4 obtained by papermaking is laminated on the upper surface of the surface layer portion 2. Then, there is a method of manufacturing the inorganic base plate 6 by pressing and integrating.

Further, the manufacturing method is not limited to the method of sequentially laminating the surface layer portion 2 and the thin film layer 4 on the upper surface of the intermediate layer forming layer 8 to be the intermediate layer portion 1 as described above. For example, as shown in FIG. Mineral fiber obtained by integrally forming a thin film layer 4 made of pulp and an inorganic powder on one surface, and one remaining surface of the surface layer 2 made of an inorganic powder are arranged on the exposed upper surface of the middle layer forming layer 8. The inorganic base plate 6 may be manufactured by lamination and integration.

As described above, when the wet method and the dry method are combined, the specific gravity of the final product can be easily adjusted by adjusting the amount of the mixture 7 forming the middle layer forming layer 8 and the pressing pressure. There are advantages.

Further, in the above-described manufacturing method, the case where the wet method and the dry method are combined has been described. However, the present invention is not limited to this, and all the steps may be performed by the wet method. For example, as shown in FIG. 4, an inorganic foam, a mineral fiber, a binder, and an organic fiber are put into water and mixed to obtain an aqueous slurry, which is wet-processed and wet-processed to form a middle layer 1 (a middle layer). The mineral fiber, the inorganic powder, the binder, and the organic fiber are suspended in water to obtain an aqueous slurry. The aqueous slurry is wet-processed to form the surface layer portion 2 and the back layer portion 3. After obtaining the wet mat, the wet mats to be the surface layer portion 2 and the back layer portion 3 are respectively laminated on the front and back surfaces of the wet mat (the intermediate layer forming layer) to be the intermediate layer portion 1 to form a laminate 9. Then, the pulp, the inorganic powder, the binder, and the coagulant are put into water and mixed to obtain an aqueous slurry, and a wet sheet to be a thin film layer 4 obtained by papermaking is laminated on the surface layer portion 2. There is a method of manufacturing the inorganic base plate 6 by pressing and integrating.

When the front and back layer portions 2, 3 and the thin film layer 4 are separately formed, the thickness of each of the front and back layer portions 2, 3 and the thin film layer 4 can be easily adjusted. It has the advantage of easy production.

Further, even when all are manufactured by a wet method, it is not always necessary to laminate the thin film layer 4 after forming the laminate 9. For example, as shown in FIG.
On the upper surface of the wet mat (middle layer forming layer), the remaining one surface of the surface layer portion 2 made of mineral fiber and inorganic powder obtained by integrally forming the thin film layer 4 made of pulp and inorganic powder on one surface is applied. Alternatively, the inorganic base plate 6 may be manufactured by laminating on the exposed one side of the wet mat (middle layer forming layer) to be the middle layer portion 1 and integrating by pressing.

The method of integrally forming the thin film layer 4 simultaneously with the surface layer portion 2 has the advantage that the steps can be omitted and the fibers of each layer are entangled, so that delamination between the surface layer portion 2 and the thin film layer 4 hardly occurs. .

Next, a method for manufacturing a five-layer inorganic base plate will be described. First, as shown in FIG.
The inorganic powder, the binder and the flocculant are put into water and mixed to obtain an aqueous slurry, which is formed into a sheet to obtain a wet sheet to be the thin film layer 5. Then, the mineral fiber, the inorganic powder, the binder, and the organic fiber are suspended in water to obtain an aqueous slurry, and the back layer portion 3 obtained by wet-making the slurry is laminated on the upper surface of the thin film layer 5. I do. Then, a mixture 7 obtained by mixing the inorganic foam, the fibrous material, and the binder is sprayed and deposited on the upper surface of the back layer 3 to form a middle layer forming layer 8 serving as a middle layer. Further, the surface layer portion 2 obtained in the same manner as the above-described back layer portion 3 is laminated on the upper surface of the intermediate layer portion forming layer 8 to form a laminate 9. On the other hand, pulp, inorganic powder, binder and flocculant are put into water and mixed to obtain an aqueous slurry,
There is a method of manufacturing an inorganic base plate 6 by laminating a wet sheet to be a thin film layer 4 obtained by making the sheet on the surface layer portion 2 and pressing and integrating them.

As another manufacturing method, for example, as shown in FIG. 7, the mixture 7 is sprayed and deposited on the remaining one surface of the back layer 3 in which the thin film layer 5 is integrally formed on one surface to form a middle layer. After the formation of the middle layer forming layer 8 which becomes 1, the remaining one surface of the surface layer portion 2 made of mineral fiber and inorganic powder obtained by integrally forming the thin film layer 4 made of pulp and inorganic powder on one surface, There is a method of manufacturing the inorganic base plate 6 by laminating and integrating the exposed upper surface of the intermediate layer forming layer 8.

In the case of manufacturing a five-layer inorganic base plate, it is not necessary to limit the process to a combination of the wet method and the dry method. May be performed by a wet method. For example, as shown in FIG. 8, an inorganic foam, a mineral fiber, a binder, and an organic fiber are put into water and mixed to obtain an aqueous slurry, which is wet-processed to obtain a wet mat to be the middle layer 1. . Then, the remaining one side of the back layer part 3 in which the wet sheet to be the thin film layer 5 is integrally formed on one side is laminated and integrated with the lower surface of the wet mat (middle layer forming layer) to be the middle layer part 1,
The remaining one surface of the surface layer 2 in which the wet sheet to be the thin film layer 4 is integrally formed on one surface is laminated and integrated on the upper surface of the wet mat (middle layer forming layer) to be the intermediate layer 1 to obtain the inorganic base plate 6. There is a way.

According to this method, the surface layer portion 2 and the thin film layer 4,
Alternatively, since the back layer portion 3 and the thin film layer 5 are integrally formed, there is an advantage that the fibers of the respective layers are entangled and delamination hardly occurs.

Further, as shown in FIG. 9, a surface layer portion 2 and a back layer material 3 are respectively laminated on the front and back surfaces of the middle layer portion 1 to form a laminate 9, and a thin film layer is formed on the front and back surfaces of the laminate 9. 4,
The inorganic base plate 6 may be formed by laminating and integrating the wet sheets 5. Further, after the surface layer portion, the middle layer portion, and the back layer portion are laminated and pressed and integrated to form a laminate, a thin film layer may be integrated at least in the surface layer portion. Further, the thin film layer, the back layer portion, the middle layer portion (middle layer portion forming layer), the surface layer portion, and the thin film layer may be sequentially laminated and integrated by pressing.

The above-mentioned laminate refers to a laminate composed of at least three layers of a surface layer, a back layer, and a middle layer (including a middle layer forming layer), and may be simply stacked and laminated. Further, each layer may be appropriately preliminarily pressed or integrally pressed as necessary. Further, the intermediate layer forming layer may be formed by spraying and depositing a mixture to form a dry type, or a wet mat obtained by wet papermaking.

Next, an embodiment according to the present invention will be described. Example 1 28 parts by weight of pulp, 68 parts by weight of aluminum hydroxide as an inorganic powder, and 4 parts by weight of starch as a binder were put into clear water and stirred to obtain a slurry having a concentration of 2%. 0.2mm thickness introduced into Fourdrinier machine
A wet sheet to be a thin film layer was formed.

On the other hand, mineral wool 4 is used as a mineral fiber.
2 parts by weight, 53 parts by weight of calcium carbonate as an inorganic powder, 1 part by weight of a fibrous material such as pulp containing heat-fusible fibers, and 4 parts by weight of starch as a binder. Along with the agent, put into clear water, stir and concentrate 2%
Was obtained, and this slurry was introduced into a fourdrinier machine different from the above, and a backing layer having a thickness of 3 mm was formed.

A total of 95 parts by weight of pearlite and shirasu foam as inorganic foam, 1 part by weight of heat-fused fiber as fibrous material, 4 parts by weight of starch and powdered phenol as binder, and With a water repellent in an amount of 40 parts by weight of fresh water, the mixture was evenly mixed under spraying to obtain a mixture for the middle layer, and this mixture was sprayed and deposited on the upper surface of the back layer to form a middle layer having a thickness of 28 mm. A layer is formed on the upper surface of the middle layer forming layer, and a surface layer having a thickness of 3 mm is formed by laminating the thin film layer on one side in the same manner as the back layer. A 34.2 mm mat-like inorganic base material was obtained.

Next, the mat-like inorganic base material was fed into a hot press at a temperature of 180 ° C., pressed and integrated to a thickness of 9 mm at a pressure of 5 kg / cm ² , and decompressed.
To obtain a four-layer inorganic base plate, which was used as a sample. The organic component of the inorganic base plate was 6.4% by weight, which was acceptable as a noncombustible material.

(Example 2) A wet sheet to be a 0.2 mm thin film layer was prepared using a 2% concentration slurry composed of 23 parts by weight of pulp, 74 parts by weight of aluminum hydroxide as inorganic powder, and 3 parts by weight of starch. A five-layer inorganic base plate was obtained by performing the same treatment as in Example 1 except that this was formed and laminated on each surface of the surface layer part and the back layer part. At this time, the total amount of the organic components was 7.0% by weight.
And can pass as a non-combustible material.

(Comparative Example 1) Except that no thin film layer was formed on each surface of the surface layer portion and the back layer portion, the same treatment as in Example 1 was carried out except that a three-layer inorganic base plate was obtained. Was used as a sample.

Test Examples The results of quality tests performed on the samples obtained in Examples 1 and 2 and Comparative Example 1 are shown below. Example 1 Example 2 Comparative Example 1 Thickness (mm) 9 9 9 Specific gravity 0.47 0.47 0.47 Flexural strength (kgf / cm ² ) 72 80 70 Surface hardness (kgf) 164 165 160 Screw penetration force (Kgf) 23 25 20 Fireproof Nonflammable Pass Nonflammable Pass Nonflammable Pass

The test results were obtained based on the following method. Flexural strength: based on JIS 5907-1977. Surface strength: Based on JIS HARDNESS TESTER. Screw penetration force: Based on a test method according to JIS A5910. Fire protection: Based on JIS A1321.

It was found that Examples 1 and 2 were superior to Comparative Example 1 in bending strength, surface hardness and screw penetration force. This is considered to be due to the lamination of the thin film layer on each surface of the surface layer portion or the front and back layer portions.

Further, when a cloth was stuck to each of the samples of Examples 1 and 2 and Comparative Example 1 and the overlapping portion of the cloth was cut with a cutter, it was possible to cut 2 m or more in Examples 1 and 2. On the other hand, in the case of Comparative Example 1, about 30
After cutting into cm, catching occurred. In addition, in the portion where the catch occurred, a part of the cloth was peeled. From the above results, it was found that Examples 1 and 2 reduced the wear of the cutter and were more excellent in workability than Comparative Example 1.

Example 3 40 parts by weight of mineral wool as mineral fiber, 50 parts by weight of inorganic powder mainly composed of calcium carbonate, 5 parts by weight of starch, 5 parts by weight of pulp and a small amount of The water repellent and the fixing agent were put into clear water and stirred to obtain a 2% slurry, which was introduced into a fourdrinier paper machine to form a surface layer portion and a back layer portion having a thickness of 3 mm.

On the other hand, a total of 90 parts by weight of pearlite and shirasu foam as inorganic foam, a total of 4 parts by weight of heat-fused fiber and pulp as fibrous material, a total of 6 parts by weight of starch and powdered phenol as binder, and These were uniformly mixed with a small amount of a water repellent under a spray of 40 parts by weight of fresh water to obtain a mixture for the middle layer, and the mixture was sprayed and deposited on the upper surface of the back layer to obtain a 28 mm thick layer. Is formed, and the surface layer is laminated on the upper surface of the middle layer.

Further, 40 parts by weight of pulp, 55 parts by weight of aluminum hydroxide, and 5 parts by weight of starch were put into clear water and stirred to obtain a 2% slurry. This slurry was formed into a 0.2 mm-thick slurry. A wet sheet serving as a thin film layer was laminated on the surface of the surface layer to obtain a mat-like inorganic base material having a thickness of 34.2 mm. Then, the mat-like inorganic base material was sent to a hot-press at a temperature of 180 ° C., pressed and integrated to a thickness of 9 mm at a pressure of 5 kg / cm ² , and decompressed.
It dried with the dryer of ° C, and obtained the inorganic base plate of four layers, and this was used as the sample. The inorganic base plate has an organic component of 12% by weight, which is acceptable as a quasi-noncombustible material.

(Example 4) Except that a thin film layer was also laminated and integrated on the surface of the back layer, the same treatment as in Example 3 was carried out to obtain a five-layer inorganic base plate, which was used as a sample. did. The organic component of the inorganic base plate is 14%, which is acceptable as a quasi-noncombustible material.

(Comparative Example 2) Except that no thin film layer was laminated on each surface of the surface layer portion and the back layer portion, a treatment was carried out in the same manner as in Example 3 except that a three-layer inorganic base plate was obtained. And The total amount of the organic components of the inorganic base plate is 10%, which is acceptable as a quasi-noncombustible material.

Test Examples The results of quality tests performed on the samples obtained in Examples 3 and 4 and Comparative Example 2 are shown below. Example 3 Example 4 Comparative Example 2 Thickness (mm) 9 9 9 Specific gravity 0.43 0.43 0.43 Flexural strength (kgf / cm ² ) 80 93 75 Surface hardness (kgf) 172 172 170 Screw penetration force (Kgf) 26 28 21 Fireproof Quasi-nonflammable pass Quasi-nonflammable pass Quasi-nonflammable pass Note that the test method is the same as that described above, and the description is omitted.

It was found that Examples 3 and 4 were superior to Comparative Example 2 in bending strength, surface hardness and screw penetration force. This is considered to be due to the provision of the thin film layer on each surface of the surface layer portion and the back layer portion as in the first and second embodiments.

Further, a cloth was attached to each sample in the same manner as in Examples 1 and 2, and the overlapping portion of the cloth was cut with a cutter.
Examples 1 and 2 and Comparative Example 1 produced almost the same results.

(Example 5) 40 parts by weight of pearlite as an inorganic foam, 45 parts by weight of rock wool as a mineral fiber, 5 parts by weight of pulp as an organic fiber, a total of 8 parts by weight of a powdered phenol resin and starch as a binder, and These were suspended in water together with a small amount of a sizing agent and the like to obtain an aqueous slurry, which was formed into a paper having a thickness of 6.5.
mm wet mat was obtained.

Rock wool 3 is used as a mineral fiber.
5 parts by weight, 45 parts by weight of calcium carbonate as an inorganic powder, 7 parts by weight of pulp as an organic fiber, a total of 8 parts by weight of a powdered phenolic resin and starch as a binder, and these together with a small amount of a sizing agent, etc. To obtain an aqueous slurry, which was formed into a paper having a thickness of 4.0.
After obtaining the surface layer portion and the back layer portion of mm, the surface layer portion and the back layer portion are respectively laminated on the front and back surfaces of the wet mat (middle layer forming layer).

Then, 30 parts by weight of pulp, 65 parts by weight of aluminum hydroxide as an inorganic powder, a small amount of a binder,
An aqueous slurry is obtained by suspending the coagulant in water, and a thin film layer having a thickness of 0.1 mm obtained by paper-making is laminated on the surface of the surface layer portion, and integrated by pressing with a press to form a plate having a thickness of 9 mm. And dried to obtain a four-layer inorganic base plate having an overall specific gravity of 0.45, which was used as a sample. The calcium carbonate used had a particle size passing through 50 mesh, and the pearlite used had an average particle size of 300 μm.

(Comparative Example 3) A three-layer inorganic base plate obtained by operating in the same manner as in Example 5 except that a thin film layer was not provided on the surface of the surface layer portion was used as a sample.

When the screw penetration force of each sample was measured, it was 21 kgf in Example 5 and 16 kgf in Comparative Example 3. This is considered to be because the thin film layer provided on the surface of the surface layer portion improves the brittleness of the inorganic base plate.

Further, a cloth was stuck to the surface of each sample of Example 5 and Comparative Example 3, particularly to the surface of the thin film layer in Example 5, and the overlapping portion of the cloth was cut with a cutter. In the case of No. 5, continuous cutting of 2 m or more was possible, while in the case of Comparative Example 3, about 30 m was cut.
After the cm cutting, snagging began to occur. Also,
At the portion where the catch occurred, a part of the cloth was peeled. From this result, it was found that Example 5 had better cutter suitability than Comparative Example 3.

[0062]

As is clear from the above description, according to the inorganic base plate of the present invention, either the surface of the surface layer or the back layer where the mineral fibers are exposed is covered with pulp or the like. Therefore, even when the overlapping portion of the cloth is cut by the cutter when the cloth is applied, the cutting edge of the cutter is less likely to be worn, the replacement period of the cutting edge of the cutter is lengthened, and the workability is improved. In addition, since the surface of the surface layer is covered with the thin film layer containing a large amount of pulp, the bending strength is improved as compared with the case where the thin film layer is not provided, and especially when both are provided on both surfaces. Further, even when the thin film layer is provided only on the surface layer, the screw penetration force increases. In addition, the obtained inorganic base plate is 40% or more lighter in weight than a gypsum board generally used as a base material, and can be loaded to the full loading capacity of a truck. This has the effect of reducing logistics costs and facilitating transport and handling to the construction site.

[Brief description of the drawings]

FIG. 1A is a schematic perspective view showing a five-layer inorganic base plate according to the present invention. (B) is a schematic perspective view showing a four-layer inorganic base plate according to the present invention.

FIG. 2 is a schematic process chart showing a method for producing a four-layer inorganic base plate according to the present invention.

FIG. 3 is a schematic process chart showing a method for manufacturing another inorganic base plate of four layers according to the present invention.

FIG. 4 is a schematic process chart showing a method for manufacturing another inorganic base plate of four layers according to the present invention.

FIG. 5 is a schematic process chart showing a method for manufacturing another four-layer inorganic base plate according to the present invention.

FIG. 6 is a schematic process chart showing a method for producing a five-layer inorganic base plate according to the present invention.

FIG. 7 is a schematic process chart showing a method for manufacturing another inorganic base plate of five layers according to the present invention.

FIG. 8 is a schematic process chart showing a method for manufacturing another five-layer inorganic base plate according to the present invention.

FIG. 9 is a schematic process chart showing a method for manufacturing another five-layer inorganic base plate according to the present invention.

DESCRIPTION OF SYMBOLS 1 ... Middle layer part, 2 ... Surface layer part, 3 ... Back layer part, 4, 5 ... Thin film layer, 6 ... Inorganic base plate, 7 ... Mixture, 8 ... Middle layer part forming layer, 9 ... Laminate.

────────────────────────────────────────────────── ─── Continuation of the front page (56) References JP-A-6-2404 (JP, A) JP-A 5-178650 (JP, A) JP-A 4-161554 (JP, A) (58) Field (Int.Cl. ⁷ , DB name) E04F 13/00 E04F 13/08

Claims (6)

(57) [Claims] A thin film layer made of pulp and an inorganic powder material is provided on at least one of the surface layer portion and the back layer portion made of a mineral fiber and an inorganic powder material laminated on the front and back surfaces of a middle layer portion. An inorganic base plate characterized by being laminated and integrated. 2. At least the surface layer of a laminate formed by disposing a middle layer forming layer made of an inorganic foam and a fibrous material between a surface layer made of mineral fibers and an inorganic powder and a back layer. A method for producing an inorganic base plate, comprising: laminating a thin layer made of pulp and an inorganic powder on the surface of a part and pressing and integrating the thin layer. 3. A pulp and an inorganic powdery material on an upper surface of an intermediate layer forming layer made of an inorganic foam and a fibrous material disposed on an upper surface of a back layer portion made of a mineral fiber and an inorganic powdery material. A method for producing an inorganic base plate, comprising laminating a surface layer portion made of a mineral fiber having a thin film layer and an inorganic powdery material and pressing and integrating them. 4. A mineral fiber and an inorganic powdery material are provided on an upper surface of a middle layer forming layer made of an inorganic foam and a fibrous material disposed on an upper surface of a back layer portion made of a mineral fiber and an inorganic powdery material. A method for producing an inorganic base plate, comprising laminating a surface layer portion, a pulp, and a thin film layer composed of an inorganic powdery material in order, and pressing and integrating them. 5. A method according to claim 1, wherein a back layer made of a mineral fiber and an inorganic powder having a thin film layer made of pulp and an inorganic powder on a lower surface and a surface layer made of a mineral fiber and an inorganic powder. On the surface of the surface layer of the laminate formed by disposing the middle layer forming layer composed of an inorganic foam and a fibrous material, a thin film layer composed of a pulp and an inorganic powder is laminated and pressed and integrated. A method for producing a characteristic inorganic base plate. 6. A middle layer forming layer made of an inorganic foam and a fibrous material disposed on an upper surface of a backing layer made of a mineral fiber and an inorganic powder having a thin film layer made of pulp and an inorganic powder on a lower surface. A method for producing an inorganic base plate, comprising laminating a mineral fiber having a thin film layer composed of pulp and an inorganic powder on the upper surface thereof and a surface layer portion composed of an inorganic powder, and pressing and integrating them. .