JPH06264587A - Inorganic substrate plate and manufacture thereof - Google Patents

Abstract

PURPOSE:To obtain a lightweight substrate plate having the excellent cutter suitability by forming a thin film layer consisting of pulp and inorganic powder body, on each surface of an obverse layer part and a reverse layer part each of which consists of mineral fibers and inorganic powder body which are laminated on the obverse and reverse surfaces of an intermediate layer part. CONSTITUTION:Mineral fiber, inorganic powder body, bonding agent, etc., are suspended in water, and a humid mat which serves as reverse layer part 3 is formed through the humid skimming. Then, a mixture 7 which is formed by mixing the inorganic foamed body, fibrous substance, etc., is dispersed and piled on the upper surface of the reverse layer part 3, and an intermediate layer part formation layer 8 which serves as the intermediate layer part is formed. An obverse layer part 2 which is obtained similarly is piled on the upper surface of the intermediate layer part formation layer 8, and a laminated body 9 is formed. Further, pulp, inorganic powder body, coagulating agent, etc., are supplied into water and mixed, and the aqueous slurry is obtained through mixing, and a humid sheet which serves as a thin film layer 4 is obtained through skimming, and this sheet is laminated on the upper surface of the obverse layer part 2, and an inorganic substrate plate 6 consisting of four layers is manufactured through the compression integration formation.

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 as a wall base, and more particularly to an inorganic base plate capable of reducing wear of a cutting edge of a cutter when applying cloth and a method for producing the same.

[0002]

2. Description of the Related Art Conventionally, since a gypsum board is heavy, an inorganic base plate which is made lighter is, for example, a surface of an intermediate layer composed mainly of an inorganic foam and a fibrous material added as a reinforcing material. It is considered that the front layer portion and the back layer portion, which are made of mineral fibers 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, since the mineral fibers having the same hardness as the cutting edge of the cutter having the Mohs hardness of 6 to 7 are exposed on the surface, the cloth bonding is performed. When cutting the overlapping part of the cloth with a cutter at the time of cutting, the cutting edge of the cutter is likely to wear and a catching operation will start to occur in the cutting work of about 30 cm, so the cutting edge of the cutter must be replaced often, and the wall base plate When used as, there is a problem that workability is poor.

[0004]

DISCLOSURE 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 are exposed, and then cross-bond it. Focusing on the reduction of wear of the cutting edge of the cutter at that time, the present invention has been completed based on this finding.

As shown in FIG. 1, the gist of the present invention is to provide 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. In the inorganic base plate 6, a thin film layer 4 (5) made of pulp and an inorganic powder is laminated and integrated on the surface of the.

As a method of manufacturing the inorganic base plate, the thin film layer 4 (on the surface of at least one of the laminates formed by laminating the surface layer 2 and the back layer 3 on the front and back surfaces of the middle layer 1). 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 laminated body, there is a method of laminating the surface layer 2 in which at least the thin film layer 4 is integrally formed.

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

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 fibers, plant fibers such as pulp and synthetic fibers such as olefins.

The binder is added to bond and integrate the inorganic foam and the mineral fiber, and examples thereof include synthetic resins such as acrylic resin and phenol resin, and starch. In particular, since starch swells and has a sufficient bonding effect even in a small amount, it is very effective in producing a lightweight non-combustible material or quasi-incombustible material.

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

However, in order to obtain a desired fireproof property, that is, a quasi-incombustible material, it is necessary that the total amount of both the organic fiber and the binder is 15% by weight or less of the total amount. It is necessary that the total amount of organic components is 7% by weight or less of the total.

Further, the reason why the specific gravity of the middle layer portion 1 is 0.5 or less is that the surface layer portion 2 or the back layer portion 3 must have a high specific gravity in order to secure predetermined strength, hardness, etc. Part 1
This is because it is difficult to reduce the weight of the inorganic base plate 6 when the specific gravity is 0.5 or more.

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

The mineral fibers used for the front layer portion 2 and the back layer portion 3 can be arbitrarily selected from the mineral fibers for forming the middle layer portion 1, but 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 portion 2 and the back layer portion 3 is 20.
It is preferably about 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 deteriorated. This is because the addition amount of is relatively decreased, the desired surface hardness cannot be obtained, and the nail holding force is not sufficient.

The inorganic powder is added in order to increase the hardness and secure the screwing performance while maintaining the fireproof property. For example, calcium carbonate, silica, micro silica, slag, aluminum hydroxide, etc. Is used. The average particle size of the inorganic powder should be 40 to 300 μm, and particularly when the inorganic powdery substance of about 100 μm is used, the strength of the surface layer 2 and the back layer 3 becomes maximum.

The material and the amount of the binder and organic fiber added to form the front layer 2 and the back layer 3 may be appropriately selected according to need and are not particularly limited.

The specific gravity of the surface layer 2 and the back layer 3 must be 0.6 or more. If the specific gravity is less than 0.6, the dense surface layer portion 2 and the back layer portion 3 having a desired hardness are obtained.
Because I can't get it.

The thin film layer 4 (5) formed on the surface of at least one of the surface layer portion 2 and the back layer portion 3 is suitable for the cutter 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. And is mainly composed of pulp and an inorganic powder, and is formed by adding an appropriate amount of a binder.

The pulp is added to hold the inorganic powdery material described later, and examples thereof include wood pulp, recycled pulp, synthetic pulp and the like. The composition ratio of pulp in the thin film layers 4 and 5 is preferably 20 to 60% by weight. If it is less than 20% by weight, it is difficult to hold the inorganic powder and the surface becomes powdery, and it becomes difficult to apply the adhesive. On the contrary, if it exceeds 60% by weight,
This is because even if the thickness is predetermined, the amount of organic matter is large, so that the fire resistance is deteriorated.

The inorganic powder is mainly added to ensure the smoothness of the surface and 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, it is effective in terms of fire protection because it is a crystallized powder which itself has bound water.
Further, since aluminum hydroxide is less powdery than calcium carbonate, it exhibits better adhesiveness when cross-bonding.

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

The binder is used to bond and integrate the pulp and the inorganic powder, and 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 thin film layers 4 and 5 have a thickness of 0.05 to
It is preferably 0.4 mm. Thickness is 0.05mm
This is because if it is less than 0.4 mm, the cutting edge of the cutter will bite into the surface layer portion 2 or the back layer portion 3 and the cutter suitability cannot be improved, and if it exceeds 0.4 mm, the fire resistance is deteriorated.

Next, a method of manufacturing the inorganic base plate according to the present invention will be described. First, as a method for producing a four-layer inorganic base plate, for example, as shown in FIG. 2, mineral fiber, inorganic powder, binder, and organic fiber are suspended in water to obtain an aqueous slurry. This is wet-processed to obtain a wet mat which becomes the back layer part 3. Then, the mixture 7 obtained by mixing the inorganic foam, the fibrous substance and the binder is sprayed and deposited on the upper surface of the back layer 3 to form the middle layer forming layer 8 which becomes the middle layer. Then, the surface layer portion 2 obtained in the same manner as the 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 coagulant are put in water and mixed to obtain an aqueous slurry, and a wet sheet which is 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 integrally pressing.

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 middle layer portion forming layer 8 which becomes the middle layer portion 1 as described above. For example, as shown in FIG. The thin film layer 4 made of pulp and inorganic powder is integrally formed on one surface, and the remaining one surface of the surface layer part 2 made of mineral fibers and inorganic powder is placed on the exposed upper surface of the intermediate layer forming layer 8. The inorganic base plate 6 may be manufactured by laminating and integrating them.

By combining the wet method and the dry method as described above, the specific gravity of the final product can be easily adjusted by adjusting the spraying amount and the press pressure of the mixture 7 for forming the intermediate layer forming layer 8. 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, but the present invention is not limited to this, and all 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-paper-formed to form a middle layer portion 1 as a wet mat (middle layer). (Part forming layer), while mineral fiber, inorganic powder, binder, and organic fiber are suspended in water to obtain an aqueous slurry, which is wet paper-formed to form a surface layer 2 and a back layer 3. After obtaining the wet mat, the wet mat to be the front layer portion 2 and the back layer portion 3 are laminated on the front and back surfaces of the wet mat to be the middle layer portion 1 (middle layer forming layer) to form a laminate 9. Then, pulp, an inorganic powder, a binder and a coagulant are put into water and mixed to obtain an aqueous slurry, and a wet sheet which is 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 integrally pressing.

When the front and back layer portions 2 and 3 and the thin film layer 4 are separately manufactured, the thicknesses of the front and back layer portions 2 and 3 and the thin film layer 4 can be easily adjusted. It has the advantage of being easy to produce.

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

The method of integrally forming the thin film layer 4 at the same time as the surface layer portion 2 has an advantage that the steps can be omitted, and the fibers of each layer are entangled with each other, so that delamination between the surface layer portion 2 and the thin film layer 4 is unlikely to occur. .

Next, a method for producing a five-layer inorganic base plate will be described. First, as shown in FIG. 6, pulp,
An inorganic powder, a binder and a coagulant are put into water and mixed to obtain an aqueous slurry, and a wet sheet which is a thin film layer 5 obtained by papermaking is obtained. 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 papermaking is laminated on the upper surface of the thin film layer 5. To do. Next, the mixture 7 obtained by mixing the inorganic foam, the fibrous substance and the binder is sprayed and deposited on the upper surface of the back layer 3 to form the middle layer forming layer 8 which becomes the middle layer. Further, the surface layer portion 2 obtained in the same manner as the back layer portion 3 is laminated on the upper surface of the middle layer portion forming layer 8 to form a laminate 9. On the other hand, pulp, inorganic powder, binder and coagulant 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, which will be a thin film layer 4 obtained by papermaking this, on the surface layer portion 2 and pressing and integrating the same.

As another manufacturing method, for example, as shown in FIG. 7, the mixture 7 is sprinkled and deposited on the remaining one side of the back layer 3 integrally formed with the thin film layer 5 on one side to form the middle layer. After forming the intermediate layer forming layer 8 which becomes 1, the thin film layer 4 made of pulp and inorganic powder is integrally formed on one surface, and the remaining one surface of the surface layer portion 2 made of mineral fiber and inorganic powder is 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.

Further, in the case of producing a five-layer inorganic base plate, it is not necessary to limit the combination of the wet method and the dry method, and all steps are the same as in the case of producing a four-layer inorganic base plate. 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-paper-formed to obtain a wet mat to be the middle layer 1. . Then, the remaining one surface of the back layer portion 3 integrally formed on one surface of the wet sheet to be the thin film layer 5 is laminated and integrated on the lower surface of the wet mat (middle layer portion forming layer) to be the middle layer portion 1,
A wet sheet which is the thin film layer 4 is integrally formed on one surface, and the remaining one surface of the surface layer portion 2 is laminated and integrated on the upper surface of the wet mat (middle layer forming layer) which is the middle layer 1 to obtain an 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, the fibers of the respective layers are entangled with each other, which is advantageous in that delamination hardly occurs.

Further, as shown in FIG. 9, the front layer 2 and the back layer 3 are laminated on the front and back surfaces of the intermediate layer 1 to form a laminate 9, and then the thin film layers are formed on the front and back surfaces of the laminate 9. 4,
The inorganic base plate 6 may be formed by stacking and integrating the wet sheets 5 to be integrated. Alternatively, the surface layer portion, the middle layer portion, and the back layer portion may be laminated and pressed together to form a laminated body, and then the thin film layer may be integrated at least on the surface layer portion. Further, the thin film layer, the back layer portion, the intermediate layer portion (intermediate layer portion forming layer), the surface layer portion and the thin film layer may be sequentially laminated and pressure-integrated.

The above-mentioned laminate means a laminate comprising at least three layers of a surface layer portion, a back layer portion and an intermediate layer portion (including the intermediate layer forming layer), and may be simply stacked and laminated. Further, if necessary, each layer may be appropriately pre-pressed, or may be press-integrated. Further, the middle layer forming layer may be formed by a dry method by spraying and depositing a mixture, or may be a wet mat obtained by wet papermaking.

Next, examples 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 added to fresh water and stirred to obtain a slurry having a concentration of 2%. 0.2mm thickness when introduced into Fourdrinier paper machine
Was formed into a thin film layer.

On the other hand, mineral wool 4 as a mineral fiber
2 parts by weight, 53 parts by weight of calcium carbonate as an inorganic powder, 1 part by weight of fibrous material such as pulp containing heat-sealing fibers, and 4 parts by weight of starch as a binder. 2% concentration by pouring into fresh water with stirring
Was obtained, and this slurry was introduced into a fourdrinier paper machine different from the one described above to make a back layer part having a thickness of 3 mm.

A total of 95 parts by weight of pearlite and shirasu foam as an inorganic foam, 1 part by weight of a heat-sealing fiber as a fibrous substance, a total of 4 parts by weight of starch and powdered phenol as a binder, and a little of these were added. A uniform amount of water repellent and 40 parts by weight of fresh water was mixed to obtain a mixture for the middle layer. The 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, and further, on the upper surface of the middle layer forming layer, a papermaking process is carried out in the same manner as the backing layer, and a 3 mm-thick surface layer part obtained by laminating the thin film layer on one side is laminated, A 34.2 mm matt inorganic base material was obtained.

Then, the mat-like inorganic base material was sent to a hot press at a temperature of 180 ° C., and was pressed and integrated at a pressure of 5 kg / cm ^{2 to} a thickness of 9 mm to release the pressure.
Was dried by a drier to obtain a four-layer inorganic base plate, which was used as a sample. The organic component of this inorganic base plate was 6.4% by weight, which is acceptable as a noncombustible material.

Example 2 Using a slurry having a concentration of 2% consisting of 23 parts by weight of pulp, 74 parts by weight of aluminum hydroxide as an inorganic powder and 3 parts by weight of starch, a wet sheet as a thin film layer of 0.2 mm was prepared. The same procedure as in Example 1 was performed except that the layer was formed and laminated on each surface of the front layer portion and the back layer portion to obtain a 5-layer inorganic base plate, which was used as a sample. The total amount of organic components at this time is 7.0% by weight.
It is a nonflammable material that can be passed.

(Comparative Example 1) A three-layer inorganic base plate was obtained by the same procedure as in Example 1 except that the thin film layer was not formed on each surface of the surface layer portion and the back layer portion. Was used as a sample.

Test Example The results of the quality test conducted 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 Bending 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 are obtained based on the following method. Bending strength: Based on JIS 5907-1977. Surface strength: Based on JIS HARDNESS TESTER. Screw penetration force: Based on the test method according to JIS A5910. Fire resistance: 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. It is considered that this is because a thin film layer was laminated on each surface of the surface layer portion or the front and back layer portions.

A cloth was attached to each sample of Examples 1 and 2 and Comparative Example 1, and the overlapping portion of the cloth was cut with a cutter. In the case of Examples 1 and 2, it was possible to cut by 2 m or more. On the other hand, in the case of Comparative Example 1, about 30
After cutting by cm, scratches began to occur. In addition, peeling occurred in a part of the cloth in the portion where the catch was generated. From the above results, it was found that Examples 1 and 2 have less cutter wear than Comparative Example 1 and are superior in workability.

Example 3 40 parts by weight of mineral wool as a mineral fiber, 50 parts by weight of an inorganic powder mainly composed of calcium carbonate, 5 parts by weight of starch as a binder, 5 parts by weight of pulp, and a small amount of A water repellent and a fixing agent were put into fresh water and stirred to obtain a 2% slurry, which was introduced into a Fourdrinier paper making machine to make a 3 mm thick surface layer and back layer.

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

Further, 40 parts by weight of pulp, 55 parts by weight of aluminum hydroxide, and 5 parts by weight of starch are put into fresh water and stirred to obtain a slurry of 2%. The slurry having a thickness of 0.2 mm is obtained. A wet sheet to be 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., and was pressed and integrated at a pressure of 5 kg / cm ^{2 to} a thickness of 9 mm to release the pressure, and then the temperature was set to 200 ° C.
It was dried in a dryer at ℃ to obtain a four-layer inorganic base plate, which was used as a sample. The organic component of this inorganic base plate was 12% by weight, which is acceptable as a semi-incombustible material.

Example 4 Except that a thin film layer was also laminated and integrated on the surface of the back layer, the same process as in Example 3 was carried out to obtain 5 layers of an inorganic base plate, which was used as a sample. did. The organic component of this inorganic base plate is 14%, which is acceptable as a semi-incombustible material.

(Comparative Example 2) A three-layer inorganic base plate was obtained in the same manner as in Example 3 except that a thin film layer was not laminated on each surface of the surface layer portion and the back layer portion. And The total amount of organic components in this inorganic base plate is 10%, which is acceptable as a semi-incombustible material.

Test Examples The results of the quality tests conducted 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 Bending strength (kgf / cm ² ) 80 93 75 Surface hardness (kgf) 172 172 170 Screw penetration force (Kgf) 26 28 21 Fire resistance Quasi-non-combustible pass Quasi-non-flammable pass Quasi-non-flammable pass Since the test method is the same as that described above, its explanation 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. It is considered that this is because thin film layers were provided on the respective surfaces of the surface layer portion and the back layer portion, as in Examples 1 and 2.

Further, a cloth was attached to each sample and the overlapping portion of the cloth was cut with a cutter in the same manner as in the above-mentioned Examples 1 and 2, and Examples 3 and 4 and Comparative Example 2 were obtained.
The results of Examples 1 and 2 and Comparative Example 1 were almost the same.

(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, 8 parts by weight of powdered phenol resin and starch as a binder, and , These were suspended in water together with a small amount of a sizing agent to obtain an aqueous slurry, which was paper-formed to a thickness of 6.5.
A mm wet mat was obtained.

Rockwool 3 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, 8 parts by weight of powdered phenolic resin and starch as a binder, and a small amount of sizing agent and the like in water. Aqueous slurry was obtained by suspending in a papermaking machine to make a paper with 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 laminated on the front and back surfaces of the wet mat (middle layer portion forming layer), respectively.

Next, 30 parts by weight of pulp, 65 parts by weight of aluminum hydroxide as an inorganic powder, a small amount of binder,
A flocculant is suspended in water to obtain an aqueous slurry, and a thin film layer having a thickness of 0.1 mm obtained by papermaking is laminated on the surface of the surface layer portion and press-bonded integrally by a press to form a plate having a thickness of 9 mm. It was made into a body 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 of 50 mesh, and the perlite used had an average particle size of 300 μm.

(Comparative Example 3) A three-layer inorganic base plate obtained by the same operation as in Example 5 except that the 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 the case of Example 5, whereas it was 16 kgf in the case of Comparative Example 3. It is considered that this is 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 attached to the surface of each sample of Example 5 and Comparative Example 3, particularly the surface of the thin film layer in the case of Example 5, and the overlapping portion of the cloth was cut with a cutter. In the case of 5, it was possible to cut continuously for 2 m or more, whereas in the case of Comparative Example 3, it was about 30 m.
After cutting cm, a snag started to occur. Also,
Peeling occurred on a part of the cloth in the part where the catch was generated. From this result, it was found that Example 5 had better cutter suitability than Comparative Example 3.

[0062]

As is apparent from the above description, according to the inorganic base plate of the present invention, the surface of either the surface layer portion or the back layer portion 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 pasted, the cutting blade of the cutter is less likely to be worn, the replacement period of the cutting blade of the cutter is extended, and the workability is improved. In addition, since the surface of the surface layer portion is covered with a thin film layer having a high pulp content, the bending strength is improved as compared with the case where no thin film layer is provided, and particularly when the thin film layer is provided on both sides, the bending strength is further improved. Further, even when the thin film layer is provided only on the surface layer portion, the screw penetration force increases. Further, the obtained inorganic base plate is 40% or more lighter in weight than the gypsum board which is generally used as the base material, and can be loaded in the full loading capacity of the truck. Therefore, there is an effect that the physical distribution cost can be reduced, and the transportation to the construction site and the handling can be facilitated.

[Brief description of drawings]

FIG. 1 (a) is a schematic perspective view showing a five-layer inorganic base plate according to the present invention. (B) It is a schematic perspective view which shows the 4-layer inorganic base plate concerning this invention.

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

FIG. 3 is a schematic process drawing showing a method for producing another four-layer inorganic base plate according to the present invention.

FIG. 4 is a schematic process drawing showing a method for producing another four-layer inorganic base plate according to the present invention.

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

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

FIG. 7 is a schematic process drawing showing a method for producing another five-layer inorganic base plate according to the present invention.

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

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

[Explanation of symbols]

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 formation layer, 9 ... Laminated body.

Claims (6)

[Claims] 1. A thin film layer made of pulp and an inorganic powder is provided on at least one surface of a surface layer and a back layer made of mineral fibers and an inorganic powder laminated on the front and back surfaces of an intermediate layer. An inorganic base plate characterized by being laminated and integrated. 2. At least a surface layer of a laminate formed by disposing an intermediate layer forming layer made of an inorganic foam and a fibrous material between a surface layer portion made of a mineral fiber and an inorganic powder material and a back layer portion. A method for producing an inorganic base plate, characterized in that a thin film layer made of pulp and an inorganic powder is laminated on the surface of the part and integrated by pressing. 3. 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 mineral fibers and an inorganic powder, and an upper surface made of pulp and an inorganic powder. A method for producing an inorganic base plate, characterized by laminating a surface layer portion comprising a mineral fiber having a thin film layer and an inorganic powder, and pressing and integrating them. 4. A mineral fiber and an inorganic powder are provided on an upper surface of an intermediate layer forming layer made of an inorganic foam and a fibrous material, which is arranged on an upper surface of a back layer made of a mineral fiber and an inorganic powder. A method for producing an inorganic base plate, characterized in that a surface layer portion, a pulp and a thin film layer made of an inorganic powder are laminated in order and integrated under pressure. 5. Between a back layer portion comprising a mineral fiber and an inorganic powder having a thin film layer comprising a pulp and an inorganic powder on the lower surface and a surface layer comprising the mineral fiber and an inorganic powder. , A thin film layer made of pulp and an inorganic powder is laminated on the surface of the surface layer portion of the laminate formed by arranging the intermediate layer forming layer made of an inorganic foam and a fibrous material, and integrated by pressing. A method for producing a characteristic inorganic base plate. 6. An intermediate layer forming layer made of an inorganic foam and a fibrous material disposed on the upper surface of a backing layer made of mineral fibers and an inorganic powder having a thin film layer made of pulp and an inorganic powder on the lower surface. A method for producing an inorganic base plate, characterized in that a surface layer portion made of mineral fibers and an inorganic powder having a thin film layer made of pulp and an inorganic powder on the upper surface is laminated and pressed and integrated. .