JP2000313650A - Inorganic fiberboard using powdered phenolic resin and its production - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain the subject inorganic fiberboard with low powdery phenolic resin content, non-flammability and high mechanical strength, and to provide a method for producing the above fiberboard. SOLUTION: This method for producing the subject inorganic fiber board comprises the following steps: making a slurry containing inorganic fibers 1 and a resol-type powdery phenolic resin 2 with a flow length at 125 deg.C of >=25 mm, producing a wet mat by subjecting the slurry to papermaking process, dewatering the wet mat, and heating and drying the wet mat thus dewatered to cure the phenolic resin 2.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an inorganic fiberboard using a powdered phenol resin and a method for producing the same.

[0002]

2. Description of the Related Art Conventionally, as a method of manufacturing an inorganic fibrous building board using mineral fibers or the like, there are generally a forming method by dry forming and a forming method by wet papermaking. In particular, in order to improve the bending strength of the inorganic fiber plate, a forming method by wet papermaking that can more effectively utilize the dispersion and entanglement of the fiber material is used. The molding method by wet papermaking is a method in which the fiber substance and the powdered phenolic resin are put into a liquid, and the powdered phenolic resin is further dispersed by stirring and the fiber is further entangled to form a paper. The bending strength is increased as compared with the method. In addition, there are resol type and novolak type in the powder phenol resin. In the wet papermaking method, generally, the resol type powder phenol resin is used. This is because the resol type powdered phenolic resin is integral with the curing agent, whereas the novolak type requires hexamine, which is a curing agent, and since this curing agent is water-soluble, This is because most of the resin falls off and the resin hardly hardens.

Here, FIG. 2A is a schematic view showing the state of the inorganic fiber material and the powdered phenol resin in a conventional papermaking process. As shown in FIG. 2A, the inorganic fiber material 1
Are entangled with each other, and the entanglement point
Stays. The powdered phenolic resin 2 that has not stayed in the inorganic fiber material 1 falls off the mesh of the wire mesh 4 together with the water 3. FIG. 2B is a schematic view showing the appearance of the inorganic fiber material and the powdered phenol resin during heating under pressure. FIG.
As shown in (b), the inorganic fiber material 1 is compressed by being pressurized. When it is intended to obtain a high-strength plate material by utilizing the entanglement of the fibrous material 1 and the resin 2, generally, the resin 2 is adhered to the entanglement point of the fibrous material 1. It is considered that the smaller the flow is, the more effective it is. This is because, in order to obtain a fiber board having higher strength, it is important that the fibrous materials 1 are more firmly bonded to each other. Because it does not contribute much to increasing That is, if the flow of the resin 2 is large, the resin 2 attached to the entanglement point flows out onto the fibrous material 1 that is not in contact with another fibrous material 1. For this reason, it is considered that a relatively small amount of the resin 2 contributes to increase the strength, and sufficient strength cannot be obtained unless a large amount of resin is used as compared with a resin having a small flow (Japanese Unexamined Patent Application Publication No. Hei. 15330
No. 4).

On the other hand, in order to make the inorganic fiber board non-combustible (including semi-combustible), a powdered phenol resin (organic binder) is used.
Must be at least about 15% or less.
To increase the strength of the inorganic fiberboard with a low content of powdered phenolic resin, improve the dispersibility of the powdered phenolic resin in the inorganic fiberboard and efficiently use the powdered phenolic resin at the entanglement points or contact points of the inorganic fibers. Must be adhered to. In order to improve the dispersibility, it is effective to reduce the particle size of the powder phenol resin. However, when the particle size is reduced, the powder phenol resin flows down when preparing a slurry in which the inorganic fibers and the powder phenol resin are dispersed in water, and the yield is reduced. Therefore, in order to obtain high strength, it is necessary to increase the amount of addition, which is problematic in terms of cost and wastewater treatment.

[0005] Powdered phenolic resins have poor adhesion to mineral fibers. The retention of the powdered phenolic resin in the fibrous material is due to the mesh effect of the fibrous material.
Therefore, in order to keep more powdered phenolic resin in the fibrous material, it is necessary to increase the particle size of the powdered phenolic resin and to form flocs using sodium sulfate or a polymer flocculant. Is effective. However, due to these, the dispersibility of the powdered phenolic resin is reduced, so that it is necessary to increase the content of the powdered phenolic resin in order to obtain high strength, making it difficult to obtain nonflammability and disadvantageous in terms of cost. It is.

[0006]

DISCLOSURE OF THE INVENTION In view of the above problems, the present inventors have proposed an inorganic fiber board using a powdered phenolic resin which can achieve non-combustibility and high strength even if the content of the powdered phenolic resin is low, and its use. We worked diligently to develop a manufacturing method. As a result, the present inventors have focused on the flow of the powdered phenolic resin at the time of pressurized and heated, and by preventing the strength from being reduced due to insufficient dispersion of the powdered phenolic resin in the inorganic fiber plate, such a problem has been solved. I found something.

[0007]

In order to achieve the above-mentioned object, a method for producing an inorganic fiberboard using a powdered phenolic resin according to the present invention comprises the steps of:
mm, a step of preparing a slurry comprising a resol-type powdered phenolic resin, a step of papermaking the slurry to obtain a wet mat, a step of dehydrating the wet mat, and heating the dewatered wet mat. Drying and curing the phenolic resin. The inorganic fiber plate may have a compacted structure, a cell structure, or a honeycomb core shape.

[0008] Here, "flow" refers to JIS K 691
It is defined as measured at 125 ° C. according to 0. The details are as follows. 1.0 ± 0.05 g of a sample is pressed and molded at room temperature using a molding die and a molding machine to produce a test specimen having a diameter of 10 ± 0.1 mm and a height of 13 ± 0.5 mm. In a thermostat, the glass sheet kept horizontally (thickness 3 of JIS R3202)
12 mm, clean polished glass with no defects on the surface
After heating uniformly to 5 ± 1 ° C., the test piece is placed upright on a glass plate. After about 3 minutes, the glass sheet is tilted to 30 degrees. The distance from the lower end of the test piece placed upright to the hardened tip that has flowed is weighed to the nearest millimeter on the glass surface, and is defined as the flow of the sample. In this way, by using a phenol resin that has a relatively large flow during heating,
Although the dispersibility is not good, it is possible to use a powder resin having a relatively large particle diameter and excellent yield during papermaking, and the mesh effect can be exhibited, so that sufficient strength can be obtained efficiently.

The phenol resin has a flow of 120
mm or less. The phenol resin preferably has a particle size in the range of 25 to 147 μm. Further, the phenol resin preferably has a gel time at 150 ° C. in the range of 60 to 600 seconds.
Here, the “gelation time” is defined as that measured at 150 ° C. according to JIS K6910. The details are as follows. Surface temperature of 150
A spatula is placed on a steel plate that can be maintained at ± 1 ° C., and after heating the steel plate and the spatula to 150 ± 1 ° C., about 0.5 g of a sample is placed on the steel plate. At the same time as placing, start the stopwatch, spread the test piece with a spatula in a circular shape of about 3 cm in diameter, and knead it at a rate of about once a second while pressing evenly so that it does not spread. Measure the time until the thread is no longer pulled. This operation 3
The average time is expressed in seconds, and is defined as the gel time of the sample.

The inorganic fiber board using the powdered phenolic resin of the present invention is characterized in that it contains 15% by weight or less of a resol type powdered phenolic resin whose flow at 125 ° C. is 25 mm or more.

[0011]

Embodiments of the present invention will be described below. (1) Preparation of slurry First, an inorganic fiber, an organic binder, and if necessary, an organic fiber, a coagulant, and an additive are put into a large amount of water,
A slurry is prepared by stirring. By stirring, the disintegration of the inorganic fibers and the dispersion of each of the above materials can be promoted. The stirring speed and the stirring time are not particularly limited, but are preferably set such that the inorganic fibers are in a disintegrated state in which the fiber reinforcing effect is exhibited most.

As the inorganic fibers, for example, mineral fibers such as rock wool, slag wool and glass wool can be used. As the shape of the mineral fiber, it is preferable to use granular cotton. The amount of the inorganic fiber is preferably 5% by weight or less based on the total amount of the slurry,
1.0-1.5% by weight is more preferred. Further, the obtained inorganic fiber board is not particularly limited, but may be about 30
It is preferable to mix them so as to be about 95% by weight. In addition, organic fibers can be added to the inorganic fibers. Examples of the organic fiber include pulp (softwood pulp, hardwood pulp, waste paper pulp, and the like). The addition of the organic fibers has the effects of improving the yield of the resin and increasing the strength. However, the amount of addition must be 15% by weight or less, preferably 10% by weight or less in total with the organic binder. If the total content of the organic fibers and the organic binder exceeds 15%, the inorganic fiber board cannot have nonflammability. In the present invention, the term “inorganic fiberboard” including those containing a small amount of organic fibers is used.

The organic binder is preferably a resol type powder phenol resin. As physical properties of the resol-type powdered phenolic resin used in the present invention, if the flow at 125 ° C. is 25 mm or more, preferably in the range of 40 to 120 mm, and more preferably in the range of 60 to 100 mm, the other physical properties are particularly Not limited. Flow is 25mm
If it is less than 1, the strength of the obtained inorganic fiber plate decreases, which is not preferable. On the other hand, when the flow exceeds 120 mm, the gelation time tends to be long, and thus the productivity may be reduced. Further, as a preferable range of other physical properties,
The particle size of the resin is preferably about 25 to 147 μm (about 100 to 500 mesh), and particularly preferably about 200 to 400 mesh. If the thickness is less than 25 μm, the yield of the powdered phenol resin is undesirably reduced. 147 μm
If the particle size exceeds the above range, the productivity of the powdered phenol resin is undesirably reduced. The gel time at 150 ° C. is preferably from 60 to 600 seconds, and more preferably from 270 to 450 seconds. If the time is less than 60 seconds, the flow of the powdered phenolic resin will be small, and if it exceeds 600 seconds, the productivity may be reduced. The resole-type powder phenolic resin is in a powder form, so that it has good dispersibility and can be easily compounded with each filler. The compounding amount of the organic binder is 5 to
It is preferably 15% by weight, more preferably 8 to 13% by weight. Further, as in the case of the above-mentioned organic fibers, the total blending amount with the organic fibers needs to be 15% by weight or less, preferably 10% by weight or less. If it exceeds 15% by weight, generally, the inorganic fiberboard cannot obtain sufficient nonflammability. When the content is 10% by weight or less, there is an advantage that the nonflammability is improved.

By using a resol type powdered phenol resin having a flow at 125 ° C. of 25 mm or more, it is possible to prevent a decrease in the strength of the inorganic fiber board due to insufficient dispersion of the powdered phenol resin. In other words, in order to improve the yield of the powdered phenolic resin, the particle size of the powdered phenolic resin is increased to some extent, so that the dispersibility of the resin is insufficient,
Although the strength of the inorganic fiber plate is reduced, by increasing the flow of the resol type powdered phenolic resin during heating to 25 mm or more, the contact area between the inorganic fibers via the powdered phenolic resin increases, The strength corresponding to the content can be exhibited. This is contrary to the conventional idea that a smaller flow of the powdery phenol resin is more efficient in increasing the strength. However, by using the powdered phenolic resin having a large flow for an inorganic fiber plate having a compacted structure obtained by heating, in addition to increasing the bonding area between the inorganic fiber materials at the time of heat compression molding, the resin flows. This contributes to the bonding between the inorganic fiber materials, thereby making it possible to further increase the strength of the inorganic fiber plate. Similar effects can be obtained by using a lightweight inorganic fiber plate having a cell structure or a honeycomb core shape in addition to a simple consolidation structure. For example, a honeycomb core shape can be advantageously obtained by pouring a slurry from above on a flexible and resilient trapezoidal pad made of silicon rubber or the like on a net-like support, and pressing the slurry with a flat plate placed on top. . It is because the pad such as trapezoidal silicon rubber spreads sideways by pressure from above,
This is because sufficient strength can be imparted to the walls of the honeycomb core structure formed between the pads.

In order to make the structure more dense, if necessary, a sodium sulfate or a polymer flocculant can be used as a flocculant. The use of a flocculant is optional. Coagulants such as sodium sulfate and polymer coagulants have their own characteristics,
Sulfate is effective for agglomerating fine particles of about 1 μm or less, and a polymer-based flocculant is effective for agglomerating relatively coarse particles of about 1 μm or less. However, in order to effectively use these flocculants, it is necessary to devise each of them. For example, in the case of sodium sulfate, the flocculant effect varies greatly depending on the pH, and acidic is preferable in order to exert effective flocculation. In addition, polymer-based flocculants include anionic, cationic, and nonionic, depending on the chemical structure, and various molecular weights can be selected, and the flocculant effect differs greatly depending on the molecular weight. When a coagulant is used, the yield rate is 90% or more by using the sodium sulfate and the polymer coagulant alone or in combination, and using a coagulant and a combination thereof suitable for the material conditions (fiber, powder phenol resin) used. It can be. The amount of the coagulant is not particularly limited, but is preferably 0 to 3.5% by weight based on the obtained inorganic fiber plate.

Optional additives include, in addition to these, aluminum hydroxide, which is a heat absorbing substance, in order to improve flame retardancy.
Inorganic powders such as magnesium hydroxide and inorganic powders such as calcium carbonate, fly ash and slag can be optionally used as fillers. The blending amount of these inorganic powders is not particularly limited, but is preferably blended so as to be about 0 to 65% by weight based on the obtained inorganic fiber plate.

(2) Preparation of Wet Mat The slurry prepared above is formed by a commonly used paper forming method to prepare a wet mat. For example,
There is a method in which a wire mesh or a screen mesh is poured into a former box laid on the bottom, and a wet mat is produced by making a paper by gravity or forcibly evacuating. In the case where the plate material has a structure having cell voids such as a honeycomb core shape, it is manufactured by using a wire mesh in which cell-shaped silicon rubber pads are arranged at equal intervals.

FIG. 1A is a schematic view showing the appearance of the inorganic fiber material and the powdered phenol resin in the production of a wet mat. As shown in FIG. 1A, the inorganic fiber materials 1 are entangled with each other, and the powder phenol resin 2 stays at the entanglement point. The powdered phenolic resin 2 that has not stayed in the inorganic fiber material 1 falls off the mesh of the wire mesh 4 together with the water 3. Generally, the smaller the particle size of the powdered phenolic resin, the more the falling-off occurs, and the lower the yield of the powdered phenolic resin. Therefore, by using a powdered phenol resin having a large particle size, the yield can be improved and the cost of raw materials can be reduced. In addition, by improving the yield, the amount of the powdered phenol resin that has fallen into the wastewater is reduced, and the cost of wastewater treatment and the like can be reduced.

(3) Dehydration of Wet Mat The above prepared wet mat is pressed at room temperature to dehydrate excess water. Here, it is possible to heat and press and dry and harden without dehydrating, but it is preferable to perform dehydration before hot pressing in order to reduce drying energy and drying time. Further, although it takes time, after dehydration, the temperature is not higher than the reaction acceleration temperature of the powdered phenol resin (100 ° C.
Pre-drying can also be performed under the conditions of Even when the dehydration press is performed, the powder phenol resin not staying in the inorganic fiber material falls off, and the yield decreases. Therefore, the particle size of the powdered phenol resin is preferably about 25 to 147 μm, as in the case of the wet mat.

(4) Drying / Curing The wet mat, which has been dehydrated to reduce the water content, is dried and cured by heating under pressure at a temperature of 140 to 200 ° C., at a pressure of 0.6 MPa or more, for 10 minutes or more. An inorganic fiberboard having a structure is manufactured. The powdered phenolic resin is fluidized by heating and flows on the inorganic fiber material. The flow of the powdered phenolic resin of the present invention is 2 ° C at 125 ° C.
It is 5 mm or more, and the powdered phenol resin on the inorganic fiber material flows over a wider range than before. here,
FIG. 1B is a schematic diagram showing the state of the inorganic fiber material and the powdered phenol resin during heating under pressure. As shown in FIG. 1 (b), by applying pressure, the wet mat is compressed, and becomes a compacted inorganic fiber plate. The inorganic fiber materials 1 are further entangled with each other, and the bonding area between the inorganic fiber materials 1 increases. Since the inorganic fiber material 1 is also bonded to the portion where the powdered phenolic resin 2 has flowed out, the larger the flow of the powdered phenolic resin 2, the larger the bonding area between the inorganic fibered material 1 and the powdered phenolic resin 2 increases the strength. Can be done.

The inorganic fiberboard obtained by the present invention is nonflammable or semi-flammable due to its low content of organic components (mainly powdered phenolic resin). Also, even if the content of the powdered phenolic resin is small and not very well dispersed,
Since the flow of the powdered phenolic resin during heating is large, the strength of the obtained product is high, and it has sufficient strength as a building board. Furthermore, because the particle size of the powdered phenolic resin is large,
Yield is improved, and raw material costs and wastewater treatment costs can be reduced. In addition, it is possible to reduce the weight by providing such a non-combustible high-strength inorganic fiber plate with cell voids (for example, a honeycomb core structure).

[0022]

The present invention will be described in more detail with reference to examples and comparative examples, but the present invention is not limited to these examples and comparative examples. 1. Preparation of Inorganic Fiber Board As the resole type powdered phenolic resin, 11 kinds of resole type powdered phenolic resins (PF) of A to K having different physical properties as shown in Table 1 were used. In a large amount of water, powdered rock wool granular cotton (RW), resole type powdered phenolic resin (PF), and calcium carbonate powder (CaCO ₃ )
Were charged according to the material input amounts shown in Table 1 to prepare respective slurries. Further, by stirring these slurries, disintegration of the inorganic fibers and dispersion of the resin were promoted. Next, the slurry was poured into a former box in which a wire mesh having irregularities in a honeycomb core shape was laid on the bottom, and the slurry was forcibly evacuated to form a paper.
A wet mat was prepared. The produced wet mat was pressed at room temperature to dehydrate excess water. The wet mat, which has been dehydrated to reduce the water content, has a temperature of 170 ° C.
Drying and curing by heating under pressure of 1.0 MPa for 25 minutes under the conditions of pressure 1.0 MPa, Examples 1 to 10 and Comparative Example 1
To 5 were prepared.

2. Evaluation items and evaluation methods About the inorganic fiberboard of Examples 1-10 and Comparative Examples 1-5,
Table 1 shows the cross-sectional structure, plate thickness, bulk specific gravity, powder phenol resin yield (PF yield), powder phenol resin content (PF content), bending strength, bending specific strength, and flame retardancy. . In addition, bulk specific gravity, bending strength, bending specific strength,
The method for evaluating the content of the powdered phenolic resin and the target value will be described below. (1) Bulk specific gravity The inorganic fiber boards of Examples 1 to 10 and Comparative Examples 1 to 5 were cut to predetermined dimensions, and their length L, width B, thickness t, and weight W were cut.
Was accurately measured, and the bulk specific gravity ρ was calculated by the following equation. ρ = W / (LBt) In the present invention, a bulk specific gravity of 0.6 or less was targeted in order to obtain a lightweight inorganic fiber plate.

(2) Flexural strength The flexural strength of the inorganic fiberboard was measured according to JIS A 5433. In the present invention, a bending strength of 3.3 N / mm ² or more (A rank) was aimed at in order to be applicable to ceramic siding. (3) Bending specific strength The bending specific strength of the inorganic fiberboard was calculated from the bending strength / bulk specific gravity. In the present invention, the target was a bending specific strength of 5.5 N / mm ² or more. (4) Content of powdered phenolic resin A sample of several grams sampled from an inorganic fiber
By heating at 00 ° C., the powdered phenol resin was burned and calculated from the weight loss. A powder phenolic resin content of 15% or less is a "quasi-incombustible" level, and 10% or less is a "non-combustible" level. In the present invention, as nonflammable,
The target was “quasi-incombustible” or higher.

[0025]

[Table 1]

As shown in Table 1, the powder phenolic resin
Example 1 where the flow is 25 mm or more is the goal of the present invention
Bulk specific gravity 0.6 or less, bending strength 3.3 N / mm^Twothat's all,
Bending specific strength 5.5 N / mm^TwoWith the above, it has semi-flammability
An inorganic fiber board was obtained. Meanwhile, powdered phenol
In Comparative Example 1 in which the resin flow was 0 mm, the bending strength was 3.
3N / mm^TwoBelow, the strength was low. Powder pheno
Examples 2 to 6 in which the flow of the polyester resin was 25 to 118 mm
Was an inorganic fiberboard having high strength and semi-flammability. Ma
Also, by increasing the particle size of the resin,
The yield rate of fat was able to be improved. On the other hand,
Comparative Examples 2, 4, and 5 in which the flow of the knol resin is 0 to 20 mm
Is also to increase the yield by increasing the particle size of the resin.
Although it could be improved, the strength was low. Comparative Example 2
Comparative Example 3 in which the amount of powder phenolic resin added was increased,
Flexural strength 3.3 N / mm ^TwoAs described above, the bending specific strength of 5.5 N /
mm^TwoWith the above, we have achieved the strength goal,
Increased content of powdered phenolic resin, resulting in incombustibility
Did not. When the resin flow is 25mm or more,
Example 7 with a large edge is a high-strength, semi-combustible inorganic fiber.
The plate could be obtained at a higher yield. resin
With a flow of 25 mm or more and reduced resin input
Examples 8 to 10 are for obtaining high strength, non-combustible inorganic fiberboard.
I was able to. Addition of calcium carbonate powder
To obtain a nonflammable inorganic fiberboard with improved strength
I was able to.

Here, FIG. 3 is a graph showing the bending strength of the inorganic fiber plate with respect to the flow of the powdery phenol resin from the results of Examples 1 to 10 and Comparative Examples 1 to 5. FIG.
As shown in the figure, the bending strength of 3.3 N /
mm ² or more results are obtained when the resin flow is 25 m
m. FIG. 4 shows the bending strength of the inorganic fiberboard with respect to the flow of the powder phenol resin when the conditions other than the flow of the powder phenol resin were the same (that is, Examples 2 to 6 and Comparative Examples 2, 4, and 5). It is a graph showing. As shown in FIG. 4, it can be seen that the smaller the flow of the resin, the lower the bending strength of the inorganic fiber plate. Also in this case, it can be understood that the result of obtaining the bending strength of 3.3 N / mm ² or more, which is the target of the present invention, is that the flow of the resin is 25 mm or more. Further, FIG.
Is a graph showing the bending specific strength of the inorganic fiberboard with respect to the flow of the powdered phenolic resin from the results of Examples 1 to 10 and Comparative Examples 1 to 5. As shown in FIG. 5, it can be seen that the smaller the flow of the resin, the lower the bending specific strength of the inorganic fiber plate. Therefore, the bending strength, which is the target of the present invention, is 3.3 N / mm ² or more and the bending specific strength is 5.5.
To obtain a result of N / mm ² or more, as shown in FIGS.
Need more.

[0028]

As is apparent from the above description, according to the present invention, there is provided an inorganic fiberboard using a powdered phenolic resin having a low content of a powdered phenolic resin, a high incombustibility and a high strength, and a method for producing the same. Is done.

[Brief description of the drawings]

FIG. 1 (a) is a qualitative schematic diagram showing a state of an inorganic fiber material and a powdered phenol resin in producing a wet mat according to the present invention, and FIG. It is a qualitative schematic diagram which shows the state of an inorganic fiber material and a powder phenol resin.

FIG. 2 (a) is a qualitative schematic diagram showing a state of an inorganic fiber material and a powder phenol resin in a conventional papermaking process, and FIG. 2 (b) is a conventional inorganic fiber material and a powder during heating under pressure. It is a qualitative schematic diagram which shows a state of a phenol resin.

FIG. 3 is a graph showing the bending strength with respect to the flow of the powdered phenolic resin obtained from the results of Examples 1 to 10 and Comparative Examples 1 to 5.

FIG. 4 is a graph showing the bending strength with respect to the flow of the powdered phenolic resin obtained from the results of Examples 2 to 6 and Comparative Examples 2, 4, and 5.

FIG. 5 is a graph showing the bending specific strength with respect to the flow of the powdered phenolic resin obtained from the results of Examples 1 to 10 and Comparative Examples 1 to 5.

[Explanation of symbols]

 Reference Signs List 1 inorganic fiber material 2 powdered phenolic resin 3 water 4 wire mesh

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[Procedure amendment]

[Submission date] May 21, 1999 (1999.5.2
1)

[Procedure amendment 1]

[Document name to be amended] Statement

[Correction target item name] 0015

[Correction method] Change

[Correction contents]

In order to make the structure more dense, if necessary, a sodium sulfate or a polymer flocculant can be used as a flocculant. The use of a flocculant is optional. Coagulants such as sodium sulfate and polymer coagulants have their own characteristics,
Sulfate is effective for agglomerating fine particles having a size of about 1 μm or less, and a polymer-based flocculant is effective for agglomerating relatively coarse particles having a size of about 1 μm or more . However, in order to effectively use these flocculants, it is necessary to devise each of them. For example, in the case of sodium sulfate, the flocculant effect varies greatly depending on the pH, and acidic is preferable in order to exert effective flocculation. In addition, polymer-based flocculants include anionic, cationic, and nonionic, depending on the chemical structure, and various molecular weights can be selected, and the flocculant effect differs greatly depending on the molecular weight. When a coagulant is used, the yield rate is 90% or more by using the sodium sulfate and the polymer coagulant alone or in combination, and using a coagulant and a combination thereof suitable for the material conditions (fiber, powder phenol resin) used. It can be. The amount of the coagulant is not particularly limited, but is preferably 0 to 3.5% by weight based on the obtained inorganic fiber plate.

[Procedure amendment 2]

[Document name to be amended] Drawing

[Correction target item name] Figure 3

[Correction method] Change

[Correction contents]

FIG. 3

[Procedure amendment 3]

[Document name to be amended] Drawing

[Correction target item name] Fig. 4

[Correction method] Change

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[Procedure amendment 4]

[Document name to be amended] Drawing

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 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Masaaki Sagawa 1-2-3 Kiyosumi Research Laboratories, Koto-ku, Tokyo Inside Pacific Cement Co., Ltd. (72) Inventor Masahito Ando 1-2-23 Kiyosumi Koto-ku, Tokyo Pacific Inside Cement Corporation Kiyosumi Research Laboratory

Claims (6)

[Claims] 1. An inorganic fiber and a flow at 125 ° C. of 25
mm, a step of preparing a slurry comprising a resol-type powdered phenolic resin, a step of papermaking the slurry to obtain a wet mat, a step of dehydrating the wet mat, and heating the dewatered wet mat. Drying and curing the phenolic resin. A method for producing an inorganic fiberboard using a powdered phenolic resin. 2. The resol-type powdered phenolic resin,
The method for producing an inorganic fiberboard using a powdered phenolic resin according to claim 1, wherein the flow at 125 ° C is 120 mm or less. 3. The resol-type powdered phenolic resin,
The method for producing an inorganic fiberboard using a powdered phenolic resin according to claim 1 or 2, wherein the particle size is 25 to 147 µm. 4. The resol type powdered phenolic resin,
The method for producing an inorganic fiberboard using a powdered phenolic resin according to any one of claims 1 to 3, wherein the gelation time at 150 ° C is 60 to 600 seconds. 5. The method for producing an inorganic fiberboard using a powdered phenolic resin according to claim 1, wherein the inorganic fiberboard has a honeycomb core shape. 6. An inorganic fiberboard comprising 15% by weight or less of a resol-type powdered phenol resin whose flow at 125 ° C. is 25 mm or more.