JPH0633198B2 - Ceramic-based porous plate and method for manufacturing the same - Google Patents

Description

TECHNICAL FIELD The present invention relates to a ceramic-based porous plate having a two-layer structure and a method for producing the same, and more specifically, to a ceramic having a two-layer structure having communicating holes suitable for applications such as building materials. A porous porous plate and a method for manufacturing the same.

2. Description of the Related Art Conventionally, various porous plates having communicating holes have been known. Since this porous plate has good air permeability and sound absorption and is lightweight, its application is expanded to building materials and the like, and the applications such as building materials are increasing.

Of the porous plates, the porous plate is mainly made of a fiber material. The porous plate is formed by adding a suitable adhesive to a fiber material such as rock wool and glass wool.

However, in the fibrous porous plate, since the fibers of the main material are exposed or floated on the surface, it is difficult to manufacture a fibrous porous plate having a complicated uneven design on the plate surface. Only by curing, it is difficult to completely spread the liquid adhesive on the fibers on the plate surface, and it is not possible to obtain a good quality product.

In addition, inorganic particles such as ceramic particles, for example,
A ceramic-based porous plate bonded with an inorganic binder such as ethyl silicate or colloidal silica as an adhesive has also been proposed and implemented. When this binder is used, it is produced through the steps of penetration-molding-drying-firing, so it takes a long time to produce, and in order to obtain the required strength, the firing temperature is 800 to 1000 ° C. It is necessary to perform firing under the conditions of firing time of 1 to 5 hours. For this reason, it takes a long time to manufacture a ceramic-based porous plate,
There is a drawback that the manufacturing cost is higher than the material cost.

In addition to fibrous and ceramic porous plates,
A sintered porous plate composed of a sintered body of metal powder is proposed,
It is already on the market. However, since this porous plate is made of expensive metal powder as a raw material, it is more expensive than other porous plates, and it is difficult to manufacture a complicated shape.

Instead of the above porous plate, a porous plate made of a foamed synthetic resin material such as urethane foam has been proposed. However, since the pores of this expandable porous plate have a large proportion of pores that do not communicate with each other, the sound absorption characteristics deteriorate,
There is a problem that a high sound absorption coefficient cannot be obtained.

As described above, each of the conventional porous plates has advantages and disadvantages.

However, in order to be used for building materials, etc.
Properties such as sound absorption, sound insulation, heat resistance, strength, and colorability are required, but no porous plate having these properties has been proposed or implemented.

In addition, the manufacturing method does not have excellent effects such as productivity, low cost, complicated shape, and ease of manufacturing.

DISCLOSURE OF THE INVENTION Problems to be Solved by the Invention An object of the present invention is to solve these problems. Specifically, it combines all the properties required for a porous plate as a building material, and can be manufactured inexpensively and efficiently. A quality plate and a method for manufacturing the same are provided.

Means for Solving the Problem and Its Action First, the porous plate according to the present invention is a ceramics-based porous plate, and the characteristic is that the ceramics particles coated with an epoxy resin binder are ceramics particles. The surface layer comprises a porous surface layer bonded by heat curing and having communication holes, and a porous back surface layer having ceramic particles coated with a phenolic resin binder bonded by heat curing and having communication holes. And the back surface layer is integrally formed.

The porous plate having this structure can be manufactured as follows.

While the ceramic particles are coated with the epoxy resin composition binder containing the epoxy resin uncured product, the curing agent and the catalyst in advance, the phenol resin composition binder containing the phenol resin uncured product, the curing agent and the catalyst is prepared. Then, the ceramic particles are coated with, and then the mold is filled with the ceramic particles coated with the former epoxy resin composition, and the ceramic particles coated with the latter phenol resin composition are filled therewith, This is characterized by being heat-cured.

More specifically, in the present invention, in the present invention, ceramic particles are coated with a resin binder comprising a resin composition containing a uncured phenol resin, a curing agent, and a catalyst, and the ceramic particles coated with the resin binder are filled in a mold. Then, it is heated and cured to efficiently obtain a porous plate having strength, heat resistance, sound absorption, and the like. In particular, the obtained porous plate has heat resistance and can be widely used as a building material.

That is, in the porous plate according to the present invention, the binder interposed between the ceramic particles is phenol resin. Since phenolic resin contains many benzene rings, it easily carbonizes and imparts heat resistance.

Phenolic resin has such advantages, but if it contains phenolic resin, it will change color from yellow to dark brown depending on the temperature and heating time when it is heated and cured.
It is not possible to make good use of the beautifully colored ceramic particles, and it is difficult to color them with a coloring agent. Therefore, when it is used as a building material such as a wall or a parting board, there is a problem that it cannot be used unless the surface is painted and colored.

More specifically, as the binder for the ceramic particles, the uncured thermosetting resin that is solid at room temperature is (1) diallyl phthalate resin, (2) in addition to phenol resin.
Examples thereof include epoxy resins and (3) unsaturated polyester resins having high crystallinity.

All of these resins (1) to (3) do not contain a benzene ring form, or contain only a part thereof and do not contain it densely in the main chain. Therefore, normally, at a temperature of 500 ° C. or higher, it does not carbonize but completely decomposes and disappears, and it does not carbonize like a phenol resin to obtain residual strength, and has almost no heat resistance.

On the other hand, these resins (1) to (3) have the advantage that, unlike phenolic resins, they do not discolor when heated and cured. Therefore, if a paint containing a pigment or the like is added to the resin, it can be colored in a desired color. In particular, these (1) ~
When the ceramic particles are coated with the resin of (3) and a porous plate is made using the ceramic particles, the inside of the porous plate is colored, and even if mechanical processing such as drilling occurs, there is no damage or falling off. However, the color will not change.

The present invention was made by utilizing such a situation, and the ceramic particles are coated with a phenol resin binder which is inexpensive and has heat resistance even after thermosetting, and the phenol resin-coated ceramic particles serve as a base. The other back surface layer that forms one back surface layer and is bonded onto this back surface layer is formed by the ceramic particles coated with the thermosetting resin binder described in (1) to (3) above.

Further, this porous plate can be obtained efficiently and at a low cost only by filling the mold with the ceramic particles thus coated with the two types of resin binders in layers and simultaneously heat-molding.

Therefore, the porous plate according to the present invention will be specifically described with reference to the drawings.

First, FIG. 1 is a perspective view of a porous plate according to one embodiment of the present invention, and FIG. 2 is a perspective view of a mold used in manufacturing the porous plate of FIG. Figure 3 (a) and (b)
FIG. 4 is each an explanatory view of a resin-coated ceramic particle filling process in a sectional view taken along line AA of FIG. 2, and FIG. 4 shows another type of mold used for producing the porous plate of FIG. It is a perspective view.

Further, in FIGS. 1 to 4, reference numeral 1 is a porous plate, 2
Is a front surface layer, 3 is a back surface layer, 4 is a mold, 5 is a mold bottom surface, 6 is a mold side surface, 7 is a weir plate, and 8 is a heater.

As shown in FIG. 1, a porous plate 1 according to the present invention has a surface layer 2 formed by heating and curing ceramic particles coated with an epoxy resin and a ceramic layer coated with a phenol resin. The back surface layer 3 and the back surface layer 3 are integrated with each other.

The porous plate 1 can be configured as a flat plate or a complicated plate.

In the front surface layer 2 and the back surface layer 3, pores are left between the ceramic particles, and the pores communicate with each other to form communication holes, thereby forming a porous plate. In the back surface layer 3, the thermosetting resin coating the ceramic particles is a phenol resin, which is carbonized to provide heat resistance and strength.

On the other hand, in the surface layer 2, since the thermosetting resin that coats the ceramic particles is an epoxy resin, the ceramic particles themselves show the color tone, and when the pigment is added to the thermosetting resin, It has a beautiful color tone of a desired color.

More specifically, the ceramic particles commonly used in the front surface layer 2 and the back surface layer 3 are alumina, silica, zirconia, magnesia, SiC, Si ₃ N _{4 and the} like. Further, in order to reduce the weight, for example, hollow particles such as silica balloons or porous particles such as pearlite can be used. Considering the case where a silane coupling agent is added among these, examples of silica-based ceramics include silica sand and fused silica. Also,
Considering that the strength of the particle is increased with the same amount of resin, it is preferable that the particle shape is close to a sphere.

Next, as the resin binder that covers the surface of each ceramic particle, one having a predetermined strength and high adhesive strength and resin strength is preferable. In particular, when a porous plate is used as a partition wall in a room, it is also necessary to have excellent heat resistance in consideration of a fire. Further, it is preferable that the heat curing time by heating at the time of manufacturing is short in consideration of productivity. Furthermore, in the case of the surface layer, it is aesthetically preferable that the color of the ceramic particles of the raw material remains unchanged, and a resin binder having this property is preferable.

From the above, a thermosetting resin is suitable as the resin binder used for both the front and back layers of the porous plate. However, among these, a phenol resin is preferable for the back surface layer from the viewpoint of heat resistance and economy as described above, and a colorable epoxy resin is preferable for the front surface layer.

The reason for using the epoxy resin as the thermosetting resin for the surface layer without using the diallyl phthalate resin or the unsaturated polyester resin is as follows.

The diallyl phthalate resin and the unsaturated polyester resin are curing reactions using a radical initiator. However, this curing reaction is hindered by the phenolic resin used in the back surface layer and does not heat cure. From this point, epoxy resin is used.

Further, the thermosetting resin is hard to cure even if it is heated as it is, and therefore, a curing agent, a catalyst and the like are added to these resins to prepare a curable composition binder. Ingredients, pigments, etc. can also be blended.

Further, considering the easiness of handling of the ceramic particles coated with the resin composition binder as the characteristics of these thermosetting uncured resins, they are solid at room temperature and have a melting point of 60 to 120.
At ℃, the viscosity drops sharply above the melting point,
It is suitable that the ceramic particles can easily be placed on the surface.
As such a resin, a novolac type phenolic resin,
As the epoxy resin, bisphenol A type epoxy resin and alicyclic epoxy resin are suitable.

Next, the method for manufacturing the porous plate having the above structure will be described in detail as follows.

In the first stage, ceramic particles coated with a thermosetting resin are prepared as follows.

First, the ceramic particles are preheated to a temperature 20 to 200 ° C. higher than the melting point of the uncured thermosetting resin to be coated on the surface.

Charge the particles into a rotating mixer. This mixer can be either a screw type or a wing type.

Next, the solid uncured thermosetting resin is put into a mixer under stirring and melted by the heat of the preheated ceramic particles. Before the ceramic particles are cooled, a curing agent, a catalyst and a silane coupling agent are added if necessary, and further water is added for cooling if necessary, and stirring is continued until the particles have cooled and become more smooth. To do.

When the ceramic particles are taken out after cooling, the surface of the ceramic particles is uniformly coated with the uncured resin composition. The amount of the uncured thermosetting resin based on the ceramic particles is 1 to 10% by weight, more preferably 2 to 5% by weight.

If it is less than 1% by weight, it will be damaged due to insufficient strength when the porous plate is taken out from the mold at a high temperature after firing and heating. Also, 1
This is because if it exceeds 0% by weight, further improvement in strength cannot be expected.

In the second stage, as described above, ceramic particles coated with a thermosetting resin such as a phenol resin binder or an epoxy resin binder are prepared, and these are used to manufacture a porous plate having a two-layer structure. .

This manufacturing method has the following two manufacturing methods, and in practice, the same method can be obtained by using either method.

The first method uses a mold 4 having a bottom surface 5, side surfaces 6 and a weir plate 7, as shown in FIG.

In this mold 4, ceramic particles coated with an epoxy resin binder are poured and filled in a state where the dam 7 is removed. Then, as shown in FIG. 3 (a), excess particles of the mold 4 are scraped off with a scraping plate at the height of the h-plane, and then the weir plate 7 is removed as shown in FIG. 2 (b). The ceramic particles that are attached and coated with a phenolic resin binder are poured and filled. Excess particles above the H surface are scraped off to obtain a uniform plate thickness.

Put this in the mold 4 and put it in the furnace for 200 ~ 300
Bake and cure at 1 ° C for 1 to 30 minutes.

In this case, in order to form the surface layer from the ceramic particles coated with the epoxy resin binder, a certain amount of raw material particles are put into the mold in advance without scraping as described above, and the particles are moved by vibration to have a constant thickness. You can also

The second method is a method of utilizing the phenomenon that when ceramic particles coated with a resin binder are heated to a temperature equal to or higher than the melting point of the coating resin, they are viscously bound before curing.

That is, as shown in FIG. 4, the heater 8 is built in advance in the mold 4 having no step and the inside of the mold 4 is kept constant at a temperature of 200 to 300 ° C.

After filling the epoxy resin binder-coated ceramic particles therein, the mixture is left for a certain period of time.

The mold is turned over to remove the ceramic particles coated with the excess resin binder that are not bound. Since the heat transfer from the mold is constant, the thickness of the particle layer attached to the mold is constant.

The mold is returned to its original position again and the state shown in FIG. 4 is obtained.
The thickness of the ceramic particle layer coated with the epoxy resin binder which becomes the surface layer 2 is adjusted by adjusting the standing time before reversal.

Next, ceramic particles coated with a phenolic resin binder are poured up to the height of the H side, and the excess ceramic particles are scraped off, and a heater-equipped upper lid (not shown).
And the ceramic particles coated with the phenolic resin binder are heat-cured and molded. The demolding may be reversed, or it may be pushed up by a knockout pin not shown in FIG. Further, in order to improve productivity, a blow molding method of particles by air pressure may be used.

According to the method described above, it is possible to obtain a porous plate having a two-layer structure having inexpensive communication holes having both heat resistance and aesthetic appearance. Further, when further heat resistance is required, a known inorganic binder aqueous solution or dispersion liquid that cures at a low temperature may be applied and impregnated from the surface. For example, Portland cement, gypsum, aluminum phosphate, etc. are effective.

Examples Examples will be described below.

Example 1. (Preparation of ceramic particles coated with phenolic resin binder) Silica particles with an average particle size of 0.4 mm (purity 98.7%) 4 kg
Is preheated to 250 ° C., put into a rotating mixer, and then a tablet-shaped novolac-type phenol resin (trade name “PSM 2240” manufactured by Gunei Chemical Co., Ltd.) 120
g was placed in the mixer. When the resin of this phenol resin was melted and uniformly coated on the silica particles, a 20% aqueous solution of hexamethylenetetramine was used as a curing agent.
0 cc (15% to resin) was added, and the particles coated with the phenol resin composition were blocked (particles coated with the molten phenol resin composition were blocked (because the molten phenol resin was cooled and changed to a solid resin). , 3% by weight of calcium stearate as a lubricant between particles was added as a lubricant between particles when the particles began to solidify during stirring, and after the particles were completely separated, they were taken out from the mixer and coated with a phenolic resin binder. Ceramic particles were prepared.

(Preparation of Ceramic Particles Coated with Epoxy Resin Binder) An alicyclic epoxy resin was used. 4 kg of silica particles having an average particle size of 0.4 mm preheated to 250 ° C. were charged into a mixer in the same manner as the phenol resin, and when the temperature reached 150 ° C., an epoxy resin having a cyclohexane ring, trade name “EHPE 31
50 "(Epoxy equivalent 172 manufactured by Daicel Chemical Industries, softening point 73 ° C) 120 g and fine powder of dicyandiamide 13.
2 g was added, and 1 minute later, 60 cc of water was added. Like the phenol resin, calcium stearate was added and taken out from the mixer to prepare ceramic particles coated with an epoxy resin binder.

(Preparation of Porous Plate) Next, a porous plate was prepared by the method shown in FIGS. 1, 2, 3 (a) and (b).

First, using the mold made of carbon shown in FIG. 1 having an inner width of 500 × 500 mm, a height from the inner bottom surface to A of 2.5 mm, and a height from the inner bottom surface to B of 8 mm shown in FIG. The ceramic particles coated with a resin binder were filled.

After scraping off with a scraping plate at the height of A side to remove excess particles, the ceramic particles coated with the phenolic resin binder obtained in the above were filled, and the excess particles were scraped off at the height of H surface.

Then, put the mold in a hot air oven, 200 ℃ × 20
Minute baking and curing, take out from the oven and remove from the mold.
A 0 mm × 500 mm × 8 mm porous plate was obtained.

In this porous plate, the surface layer was white with the silica color as it was, and the back surface layer (phenolic resin binder portion) was discolored to brown. Various test pieces were cut out from this porous plate, and various tests were conducted as described later.

Example 2. Ceramic particles coated with a phenolic resin binder were prepared in the same manner as in Example 1, ceramic particles coated with an epoxy resin binder were prepared by the following method, and a porous plate was prepared in the same manner as in Example 1. Had made.

(Preparation of Ceramic Particles Coated with Epoxy Resin Binder) 60 g of an alicyclic epoxy resin, trade name “EHPE 3160” (Epoxy equivalent 218 manufactured by Daicel Chemical Industries, softening point 60 ° C.), when charged into a mixer and reaching 130 ° C. And 18 g of dicyandiamide fine powder were added, and 1 minute later, water 1
80 cc was added. Resin was melt-coated on the surface of the particles, and as the particles started to block, 3 g of calcium stearate was added when the particles started to be blocked and taken out from the mixer after 30 seconds to obtain ceramic particles coated with an epoxy resin binder.

Example 3. The ceramic particles coated with the phenolic resin binder were prepared in the same manner as in Example 1, and the ceramic particles coated with the epoxy resin binder were prepared in the following manner. I kept it.

(Preparation of Epoxy Resin Binder-Coated Ceramic Particles) The epoxy resin is a trade name “Sumiepoxy ESA-01
4 "(Sumitomo Chemical's bisphenol A type epoxy resin, epoxy equivalent 950, softening point 95 ° C.)
0 g was added when the sand temperature reached 150 ° C., 8 g of dicyanamide was subsequently added, and the mixture was stirred. After 1 minute, 60 cc of water was added, and when the particles started to be blocked, 3 g of calcium stearate was added and coated ceramic particles were prepared with an epoxy resin binder.

For comparison, a porous plate composed of only one layer of the following Reference Examples 1 to 4 was prepared.

Reference example 1. Using the ceramic particles coated with the phenolic resin binder of Example 1, a single layer of the ceramic particles, that is, a porous plate consisting only of the back surface layer of the present invention was prepared in the same manner as in Example 1.

Reference Examples 2-4. Using the ceramic particles coated with the epoxy resin binder of Examples 1 to 3, a porous plate having only one layer was prepared in the same manner as in Example 1. It should be noted that this porous plate corresponds to the one composed only of the surface layer of the present invention.

Physical property test corresponding to Examples 1 to 3 and Reference Examples 1 to 4, (Folding test) 500 × 50 prepared in Examples 1 to 3 and Reference Examples 1 to 4.
A sample having a width of 50 mm, a length of 200 mm and a thickness of 8 mm was cut out from a 0 × 8 mm porous plate and subjected to a bending test with a span of 150 mm. The results are shown in Table 1.

The bending strengths of Examples 1 to 3 were all the same as the bending strengths of Reference Examples 1 to 4, and no decrease in strength due to multi-layering was observed.

Further, the bending strength of the porous plate of 40 kg / cm ² or more was sufficiently practical.

(Heat resistance evaluation test) A plate of 400 × 400 × 8 mm was cut out from the porous plate, and the plate was placed horizontally in a container of gold net (wire spacing 2 mm).
After firing in a furnace at 500 ° C. for 2 hours, it was taken out, cooled, and the heat resistance was evaluated from the rest.

Reference Example 1 was blackened, but was still in a state where the residual strength was considerably high.

In Reference Examples 2 and 3, all the vibrations came out from the gap of the gold net at the time of taking out, and they did not remain in the gold net container after taking out. In Reference Example 4, half the weight of the sample remained in the container after being taken out from the furnace, but it was broken by simply touching it lightly with a finger.

In each of Examples 1 to 3, the back surface layer of the ceramic particles coated with the phenolic resin binder was placed downward, and set in a furnace. As a result, in all cases, the ceramic particle side of the surface layer covered with the epoxy resin binder collapsed like the reference example. However, although the back layer is blackened,
The strength still remained, and the shape seen from above was the same as the original shape.

(Porosity measurement test) When the porosities of the porous plates of Examples 1 to 3 were measured by the water content test, all were between 45 and 55%, and the air permeability was
That is, it was confirmed that there were communication holes. Moreover, when the ventilation resistance was measured, it was 30 to 150 dyn · sec /
It was between cm ³ (Rails), and it was found that the sound absorption characteristics were excellent.

<Effects of the Invention> As described above, the porous plate according to the present invention has a two-layer structure, and one surface layer integrally includes not only ceramic particles but also ceramic particles coated with an epoxy resin binder. The back surface layer on the other side is formed by bonding ceramic particles coated with a phenolic resin binder.

Further, these two layers are cured by heating and are bonded to each other to be integrated.

Therefore, the porous plate of the present invention has high strength and sound absorption, has a coloring property by the surface layer, has heat resistance to withstand fires by the back surface layer, and has all the conditions as a building material. .

Further, it is possible to use ceramic particles, which have higher productivity and are particularly cheaper than those of the conventional porous plate, so that the production cost can be further reduced. Further, it is possible to produce not only a flat porous plate but also a porous plate having a complicated surface.

[Brief description of drawings]

FIG. 1 is a perspective view of a porous plate according to an embodiment of the present invention, FIG. 2 is a perspective view of a mold used in manufacturing the porous plate of FIG. 1, and FIG. 3 (a). 2A and 2B are explanatory views of the process of filling the resin-coated ceramic particles in the sectional view taken along the line AA in FIG. 2, and FIG. 4 is another type of gold used in manufacturing the porous plate of FIG. It is a perspective view of a type | mold. Reference numeral 1 ... Porous plate 2 ... Front surface layer 3 ... Back surface layer 4 ... Mold 5 ... Mold bottom surface 6 ... Mold side surface 7 ... Weir plate 8 ... Heater

 ─────────────────────────────────────────────────── ─── Continuation of the front page (56) References JP 62-5847 (JP, A) JP 63-60172 (JP, A) JP 51-23102 (JP, A)

Claims (4)

[Claims] 1. A porous surface layer having ceramic particles coated with an epoxy-based resin binder, the porous surface layer having communication holes bonded to each other by heating and curing, and the ceramic particles coated with a phenol-based resin binder being cured by heating. A ceramic-based porous plate, comprising a porous back surface layer which is connected to each other and has a communication hole, and the front surface layer and the back surface layer are integrally bonded. 2. A ceramic particle is previously coated with an epoxy resin composition binder containing an epoxy resin uncured product, a curing agent and a catalyst, while a phenol resin uncured product, a curing agent and a catalyst phenol are contained. The ceramic particles are coated with the resin-based resin composition binder, and then the mold is filled with the ceramic particles coated with the former epoxy-based resin composition, and the ceramics coated with the latter phenol-based resin composition on the mold. A method for producing a ceramic-based porous plate, which comprises filling particles and curing the particles by heating. 3. The amount of uncured epoxy resin or uncured phenol resin with respect to the ceramic particles is 1 to 10.
The method for producing a ceramic-based porous plate according to claim 2, wherein the content is% by weight. 4. The method for producing a ceramic-based porous plate according to claim 2, wherein the heating temperature is 200 to 300 ° C.