JP4216571B2 - INORGANIC MOLDED BODY AND PROCESS FOR PRODUCING THE SAME - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an inorganic molded body obtained by mixing, molding, heat-curing an inorganic component, a hydrophilic resin, and a silica powder, particularly an amorphous silica powder, and a method for producing the same.
[0002]
[Prior art and problems to be solved by the invention]
Conventionally, there are inorganic molded bodies formed and cured using inorganic binders such as cement on inorganic fibers such as glass fibers, but they have the disadvantage of being hard and difficult to process and heavy. On the other hand, an inorganic molded body using an organic binder as an inorganic fiber or an inorganic powder is lightweight and excellent in workability. However, in order to secure a desired strength, it is necessary to increase the addition amount of the organic binder. For this reason, there is a demand for a technique for reducing the addition amount of the organic binder and improving the strength from the standards for fire prevention. As a method for improving the strength without increasing the amount of the organic binder added, there is a method for improving the strength by adding an organic silicone monomer and firmly connecting the inorganic component and the organic component (for example, (See Patent Document 1).
[0003]
[Patent Document 1]
Japanese Patent Laid-Open No. 8-281851
However, this method can only improve the strength by about 20%, and there is a problem that a desired strength cannot be obtained if the amount of the binder added is greatly reduced.
[0005]
An object of this invention is to provide the inorganic molded object which can ensure desired intensity | strength with a small amount of organic binder, and its manufacturing method, without increasing the addition amount of an organic binder in view of the said problem.
[0006]
[Means for Solving the Problems]
As a result of intensive studies to solve the above problems, the inventors have found that the addition of a fine amorphous silica powder to a hydrophilic resin improves the strength, and the completion is based on this finding. did.
That is, the inorganic molded product according to the present invention, and an inorganic component, and a hydrophilic resin, with the amorphous silica powder-like material and the essential components of an average particle diameter of 1μm with acidic equalizing one while spraying water The mixture obtained by mixing the above is molded, heated and cured.
[0007]
In addition, the inorganic molded body according to the present invention has a wet mat obtained by wet papermaking from a slurry containing inorganic fibers, an inorganic powder and a hydrophilic resin as essential components, and has an inorganic foam and a hydrophilic resin. as essential components, and a middle layer for mixture obtained by uniformly mixing while spraying water, a middle layer disposed between the wet mat the front and back layers, heating, inorganic molded body integrated with clamping In addition, the structure characterized by having added the amorphous silica powder with an average particle diameter of 1 micrometer to the said middle layer mixture may be sufficient.
[0008]
In addition, the method for forming an inorganic molded body according to the present invention includes wet-making from a slurry containing inorganic fibers, an inorganic powder and a hydrophilic resin as essential components to obtain at least two wet mats for front and back layers, and inorganic foaming. the body and the hydrophilic resin as essential components, and, after the middle for mixture obtained by uniformly mixing while spraying water, wherein the depositing a uniform thickness between the wet mat sides layer and middle layer In the method for producing an inorganic molded body that is integrated through a hot pressing step and a drying step, an acidic amorphous silica powder having an average particle diameter of 1 μm is added to the intermediate layer mixture. There may be.
[0009]
DETAILED DESCRIPTION OF THE INVENTION
The first embodiment according to the present invention is applied to an inorganic molded body having a three-layer structure.
That is, a wet mat obtained by wet papermaking from a slurry containing inorganic fibers, an inorganic powder and a hydrophilic resin as essential components is used as the front and back layers, and the middle layer mixture containing the inorganic foam and the hydrophilic resin as essential components In the inorganic molded body that is arranged between the wet mats for the front and back layers as an intermediate layer and is integrated by heating and pressing, amorphous silica having an average particle size of 6 μm or less in at least one of the front and back layers and the intermediate layer A powdery body is added.
[0010]
Examples of inorganic fibers include rock wool, slag wool, glass wool, mineral wool, nickel wool, and glass fiber. These can be used alone or in combination of two or more. The content of inorganic fibers is preferably 20 to 60% by weight of the entire front and back layers. If the amount is less than 20% by weight, the desired bending strength cannot be obtained. If the amount exceeds 60% by weight, the proportion of the inorganic powder is relatively reduced, and the desired surface hardness cannot be ensured. is there.
[0011]
If necessary, not only inorganic fibers but also synthetic fibers such as polypropylene, polyester and vinylon, plant fibers such as hemp and flax, and wood fibers such as pulp may be added as auxiliary fibers.
[0012]
The inorganic powder is for increasing the hardness and the screwing performance while maintaining fire resistance, and examples thereof include calcium carbonate, aluminum hydroxide, slag, and the like. These may be used alone or in combination of two or more. Can be used in combination. The content of the inorganic powder is preferably 40 to 70% by weight of the entire front and back layers. This is because if it is less than 40% by weight, the desired surface hardness cannot be obtained, and if it exceeds 70% by weight, the proportion of inorganic fibers imparting strength decreases and the desired bending strength cannot be obtained.
[0013]
The hydrophilic resin is added to combine and integrate the inorganic fiber and the inorganic powder to express the final practical strength, such as potatoes, rice wheat, corn, tapioca, etc. Examples thereof include natural polymer substances such as starch and modified starch obtained from these starch-containing materials, and polymers having hydroxyl groups or carboxyl groups such as polyvinyl alcohol and polyacrylic acid. And the addition amount of the hydrophilic resin in the front and back layers is preferably 2 to 20% by weight of the entire front and back layers. This is because if it is less than 2% by weight, sufficient strength cannot be obtained, and if it exceeds 20% by weight, fire resistance is impaired.
[0014]
The inorganic foam constituting the middle layer is added to reduce the weight, and examples thereof include perlite, obsidian foam, shirasu foam, and glass foam. And it is preferable that the addition amount of the inorganic foam in a middle layer shall be 25 to 90 weight% of the whole middle layer. If the amount is less than 25% by weight, the desired weight reduction effect cannot be obtained. If the amount exceeds 90% by weight, the amount of binder and fibers added is relatively small, and the desired compressive strength is obtained. Because there is no. In addition, you may add the said inorganic powder body used for a front and back layer to a middle layer as needed. This is because the middle layer can be made dense and the nail holding power can be increased.
[0015]
The hydrophilic resin forming the middle layer is added to increase the strength by combining and integrating the inorganic foam with each other or with the inorganic foam and other inorganic constituent elements such as inorganic fibers. . The hydrophilic resin forming the middle layer is preferably 2% to 20% by weight of the whole middle layer. This is because if it is less than 2% by weight, sufficient strength cannot be obtained, and if it exceeds 20% by weight, fire resistance is impaired.
[0016]
Examples of the amorphous silica powder include silica fume, glass powder, volcanic glass powder such as shirasu, white carbon, and the like. The amorphous silica powder preferably has an average particle size of 6 μm or less, particularly 3 μm or less. This is because if the silica powder exceeds the average particle size of 6 μm, sufficient strength cannot be obtained. Further, the amorphous silica powder is not limited to neutral, and may be alkaline and acidic. In particular, a strongly alkaline or strongly acidic material may be used depending on the hydrophilic resin.
The addition amount of the amorphous silica powder in the front and back layers and the middle layer is preferably 1 to 80% by weight of the whole front and back layers and the middle layer. If the amount is less than 1% by weight, sufficient strength cannot be obtained. If the amount exceeds 80% by weight, the amount of binder, inorganic constituents and the like is relatively reduced, and a desired molded article is obtained. Because there is no.
[0017]
Next, an example of the manufacturing method of the inorganic molded body concerning this embodiment is demonstrated.
Inorganic fibers, inorganic powders, hydrophilic resins, etc. are poured into water and stirred, and further, a flocculant and other additives are added to obtain a slurry with a solid content of several percent, A wet mat that becomes a front and back layer is obtained by guiding it to a paper machine such as a round net type.
[0018]
On the other hand, an inorganic foam, inorganic fiber, inorganic powder and hydrophilic resin are uniformly mixed while spraying water to obtain a middle layer mixture. And this is spread | dispersed on the single side | surface of the said wet mat used as a lower layer, it accumulates uniformly, and the said wet mat used as an upper layer is piled up on it, and the laminated body of a 3 layer structure is obtained. Subsequently, after pressing the said laminated body with the hot-press press heated at 80 to 180 degreeC, it dries with a hot air dryer of 100 to 250 degreeC, and obtains a plate-shaped inorganic molded object.
[0019]
In addition, you may perform the said hot press by the continuous press which consists of a steel belt heated at 80 to 180 degreeC. Moreover, the front and back layers of the present invention may be produced by a dry production method, and the middle layer may be carried out by a wet production method.
[0020]
The second embodiment according to the present invention is a single-layer inorganic molded body, and a mixture comprising an inorganic component, a hydrophilic resin, and an amorphous silica powder having an average particle size of 6 μm or less as essential components is molded. And heated and cured.
[0021]
Examples of the inorganic constituent element include inorganic fibers, inorganic powders, and inorganic foams used in the first embodiment described above, and these can be used alone or in combination of two or more.
[0022]
The hydrophilic resin is added in order to bond and integrate the above-described non-mechanism components to develop final practical strength. And it is preferable that hydrophilic resin is 2 to 20 weight% of the whole inorganic molded object. This is because if it is less than 2% by weight, sufficient strength cannot be obtained, and if it exceeds 20% by weight, fire resistance is impaired.
[0023]
The addition amount of the amorphous silica powder is preferably 5 to 80% by weight of the whole inorganic molded body. If the amount is less than 5% by weight, sufficient strength cannot be obtained. If the amount exceeds 80% by weight, the amount of hydrophilic resin or inorganic constituent added is relatively small, and the desired strength cannot be obtained. Because.
[0024]
【Example】
(Examples 1-4)
Shirasu foam (average particle size 250 μm), silica fume (pH = 3.5, average) as a hydrophilic resin, polyvinyl alcohol resin as an inorganic aggregate, and amorphous silica powder as an inorganic aggregate in the ratio shown in FIG. Each particle size was mixed to obtain a mixture. Then, 50 parts by weight of water was added to 100 parts by weight of the mixture and uniformly kneaded, and then placed in a predetermined mold, and compression molded to a thickness of 5 mm and a density of 0.55 g / cm ³ . Subsequently, it dried at the temperature of 180 degreeC for 1 hour, and the sample for a test was obtained. The obtained test sample was bonded to a flat tensile test jig, and the peel strength was measured. The measurement results are shown in Chart A of FIG. 1 and graphed in FIG.
[0025]
(Examples 5 to 8)
Shirasu foam (average particle size 250 μm), silica fume (pH = 8, average particle size) as an amorphous silica powder as an inorganic aggregate, at a ratio shown in Chart B of FIG. 0.5 μm) were mixed to obtain a mixture. The others were processed in the same manner as in Example 1 to obtain a test sample, and the peel strength was measured under the same conditions as in Example 1. The measurement results are shown in Chart B of FIG. 1 and graphed in FIG.
[0026]
(Comparative Examples 1-4)
Shirasu foam (average particle size 250 μm), polyvinyl alcohol resin as a hydrophilic resin, and crystalline silica (average particle size 1 μm) as an inorganic aggregate were mixed at a ratio shown in FIG. 1 to obtain a mixture. The others were processed in the same manner as in Example 1 to obtain a test sample, and the peel strength was measured under the same conditions as in Example 1. The measurement results are shown in Chart C of FIG. 1 and graphed in FIG.
[0027]
As is clear from FIGS. 1 and 2, since all the peel strengths of Examples 1 to 8 are equal to or higher than any of the peel strengths of Comparative Examples 1 to 4, it is amorphous rather than adding crystalline silica. It was confirmed that the peel strength was improved by adding a porous silica powder. In particular, it has also been found that when the acidity of the amorphous silica powder is high, the peel strength tends to increase remarkably as the addition amount increases.
[0028]
(Examples 9 to 12)
Shirasu foam (average particle size 250 μm), starch as hydrophilic resin, silica fume as amorphous silica powder (pH = 3.5, average particle size) at the ratio shown in Chart A of FIG. 1 μm) were mixed to obtain a mixture. The others were processed in the same manner as in Example 1 to obtain a test sample, and the peel strength was measured under the same conditions as in Example 1. The measurement results are shown in Chart A of FIG. 3 and graphed in FIG.
[0029]
(Examples 13 to 16)
Shirasu foam (average particle size 250 μm), starch as hydrophilic resin, silica fume as amorphous silica powder (pH = 8, average particle size 0. 5) in the ratio shown in Chart B of FIG. 5 μm) were mixed to obtain a mixture. The others were processed in the same manner as in Example 1 to obtain a test sample, and the peel strength was measured under the same conditions as in Example 1. The measurement results are shown in Chart B of FIG. 3 and graphed in FIG.
[0030]
(Comparative Examples 5 to 8)
Shirasu foam (average particle size 250 μm), starch as the hydrophilic resin, and crystalline silica (average particle size 1 μm) as the inorganic aggregate were mixed at the ratio shown in Chart C of FIG. 3 to obtain a mixture. The others were processed in the same manner as in Example 1 to obtain a test sample, and the peel strength was measured under the same conditions as in Example 1. The measurement results are shown in Chart C of FIG. 3 and graphed in FIG.
[0031]
As is clear from FIGS. 3 and 4, since all the peel strengths of Examples 9 to 16 are equal to or higher than any of the peel strengths of Comparative Examples 5 to 8, the crystalline silica powder is added. It was also confirmed that the peel strength was improved by adding an amorphous silica powder. In particular, it has also been found that when the acidity of the amorphous silica powder is high, the peel strength tends to increase remarkably as the addition amount increases.
[0032]
【The invention's effect】
According to the present invention, by adding a fine amorphous silica powder to a hydrophilic resin, there is an effect that an inorganic molded body having high strength can be obtained without increasing the amount of organic binder added.
[Brief description of the drawings]
FIG. 1 is a chart showing examples and comparative examples according to the present invention.
FIG. 2 is a graph showing the chart of FIG. 1 as a graph.
FIG. 3 is a chart showing other examples and comparative examples according to the present invention.
4 is a graph obtained by graphing the chart of FIG. 2. FIG.

Claims (3)

An inorganic component, a hydrophilic resin, and an amorphous amorphous silica powder having an average particle diameter of 1 μm are essential components, and a mixture obtained by uniformly mixing while spraying water is molded and heated. An inorganic molded body characterized by being cured. Wet mat obtained by wet papermaking from slurry containing inorganic fiber, inorganic powder and hydrophilic resin as essential components is used as front and back layers, inorganic foam and hydrophilic resin as essential components , and water is sprayed. the middle layer for mixture obtained by uniformly mixing with, the middle layer disposed between the wet mat the front and back layers, heating, in the inorganic molded body integrated with clamping,
An inorganic molded body, wherein an amorphous silica powder having an average particle diameter of 1 μm is added to the middle layer mixture . Wet papermaking from a slurry containing inorganic fibers, inorganic powder and hydrophilic resin as essential components to obtain at least two wet mats for front and back layers, inorganic foam and hydrophilic resin as essential components , and water Inorganic molding in which the mixture for the middle layer obtained by uniformly mixing while spraying is deposited in a uniform thickness between the wet mats for the front and back layers to form a middle layer, and then integrated through a hot pressing step and a drying step In the manufacturing method of the body,
A method for producing an inorganic molded body, wherein an amorphous silica powder having an average particle diameter of 1 μm is added to the middle layer mixture .

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