JPH092881A - Foamed ceramic molded plate - Google Patents

Abstract

PURPOSE: To obtain a formed ceramic molded plate enabling the penetration of air but not enabling the penetration of water, high in a water-absorbing performance, and excellent in a heat-insulating performance by kneading specific fine hollow ceramic particles with a ceramic composition component containing a material used as a flux, press-molding the kneaded product, and sintering the molded product. CONSTITUTION: A foamed molded plate is produced by kneading a composition comprising 100 pts.wt. of fine hollow ceramic particles having a composition strength of >=600kgf/cm<2> , bulk density of 0.3-0.5g/cm<3> and a melting point of >=1500 deg.C and 10-300 pts.wt. of a ceramic composition component containing a material used as a flux, fed in a mold, press-molded and subsequently sintered at 700-1300 deg.C. The used fine hollow ceramic particles have especially high compression strength in comparison with conventional fine hollow foamed products, and can resist against high stress and shear forces caused in the process for producing the foamed ceramic molded product. The further press molding enables to form the foamed ceramic molded plate which is fine in spite of being lightweight.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION The present invention is used for outer wall materials, floor materials, ceiling materials, roof tiles, roof tiles, sound absorbing materials, construction / civil engineering materials such as water-permeable pavement materials, and other filters and air diffusers used for construction. The present invention relates to a foamed ceramic molded plate.

[0002]

2. Description of the Related Art Conventionally, there have been the following types of foamed ceramic molded plates or porous ceramic molded plates. That is, a mixture of natural minerals such as porcelain stone, feldspar, and clay, or oxide-based ceramic powder to which a binder is added, an inorganic or organic foaming agent is added, and the mixture is kneaded and molded, followed by firing at a high temperature of 1000 ° C or higher. Are known.

Further, a porosifying agent or a foaming agent is added to a slurry containing ceramic powder and a binder, and the slurry is molded and fired. Further, a ceramic porous molded plate in which an inorganic fine foam or a ceramic fragment is bound by a binder is also widely used.

[0004] However, in the case of using natural minerals such as porcelain stone, feldspar and clay as a raw material, good quality materials are gradually decreasing and it is difficult to obtain them. Further, in the method using a porosifying agent, a large amount of the porosifying agent must be used in order to produce a foamed ceramic molded plate having a high porosity and a high pore diameter, and the porosifying agent is dispersed in the slurry and scattered during firing. It is difficult to stabilize the quality because it damages the foam ceramic molded plate.

In the method using a foaming agent, it is difficult to form regular fine hollows as designed. Inorganic microfoam or ceramic shards that are bound by a binder have irregular shapes such as inorganic microfoam or ceramic shards, and the surface of these is not smooth, which results in large absorption of binder and poor quality stability. It does not result in a good quality foam ceramic molded plate.

As described above, the conventional foamed ceramic molded plate or porous ceramic molded plate has a fine void inside the ceramic molded plate, or the periphery of the fine foamed body is simply solidified with a binder or the like. there were. For this reason, in the foamed ceramic molded plate, air cannot penetrate, or in the case of air diffuser plate and filter, there are only large air flow holes, and the strength and heat insulation are low. The fire resistance was not enough.

[0007]

DISCLOSURE OF THE INVENTION The present invention solves the problems of the conventional foamed ceramic molded plate as described above, is lightweight and has strength, and is a microcapillary air of a micron unit through which air flows. By having a flow hole, it is possible to provide an excellent foamed ceramic molded plate that allows air to pass through but does not allow water to pass therethrough, has extremely high water absorption performance and excellent heat insulation performance, and has an extremely low backside temperature rise against a flame. To aim.

[0008]

[Means for Solving the Problems] The above-mentioned problem is that the foamed ceramic molded plate is composed of innumerable perfect spherical fine hollow particles, and the fine hollow particles are connected to each other by points, so that microcapillary capillaries are provided between the fine hollow particles. It is possible to have a shape of air circulation hole.

According to the present invention, since a myriad of micron-sized capillary air flow holes are retained in the foamed ceramic molded plate, high-strength ceramic fine hollow particles are spot-bonded by a ceramic composition containing a material serving as a flux. Let them do it.

That is, 100 parts by weight of ceramic fine hollow particles having a compressive strength of 600 kgf / cm ² or more, a bulk specific gravity of 0.3 to 0.5 g / cm ³ and a melting point of 1500 ° C. or more, and a ceramic composition content of 50 to 50. 50 to 500 kgf by kneading a composition consisting of 300 parts by weight and placing it in a mold.
/ Cm ² of pressure and then demolding the molded body to 700
It is characterized by being fired at ˜1300 ° C.

The colored foamed ceramic molded body can be made into a colored foamed ceramic molded plate by spraying the ceramic fine hollow particles with a sludge-like colored inorganic pigment in advance and using the dried colored ceramic fine hollow particles.

[0012]

The ceramic fine hollow particles used in the present invention have particularly high compressive strength as compared with the conventional fine hollow foams, and can withstand the high stress and shearing force generated in the process of producing the foamed ceramic molded body. Is what you can get. Further, by performing pressure molding, a dense foamed ceramic molded plate can be obtained despite its light weight.

The compressive strength of the fine hollow foam is synonymous with the hydrostatic strength, and the compressive strength is measured by pressurizing the fine hollow foam in water and transmitting the pressure applied to the water to the fine hollow foam. The pressure at which the hollow foam breaks is the compressive strength.

A foamed ceramic molded plate capable of exhibiting excellent performance must have a sufficient kneading step, and is particularly important for a foamed ceramic molded plate of uniform quality and good quality. When performing sufficient kneading, the stress and shear force applied to the ceramic fine hollow particles during the kneading are about 400 kg.
It is said to be around f / cm ² . Since there are no conventional hollow microfoams for building materials that can withstand such a high pressure and most of them are destroyed, there is no one that can be used as such a foamed ceramic molded plate and can obtain sufficient performance.

Next, when the fine ceramic hollow particles are used in the foamed ceramic molded plate, the important factor is the thermal conductivity. Depending on the particle size of the fine hollow foam, generally 0.1 (kc
al / mhr ° C), and when half of the filled fine hollow foam is broken, the thermal conductivity is approximately 0.
2 (kcal / mhr ° C). Excellent effects can only be obtained if a completely fine hollow foam which is not destroyed is used. The ceramic fine hollow particles used in the present invention have significantly higher compressive strength than conventional fine hollow foams such as shirasu balloon, glass balloon, silica balloon, fly ash balloon, etc. The hollow body is 100% complete. Incidentally, the compressive strength of the conventional fine hollow foam is 80.
３００300 kgf / cm ² .

The melting point of the hollow ceramic fine particles used in the present invention is 1500 ° C. or higher. Naturally, the fine ceramic hollow particles are caused by their material, but generally, the higher the melting point, the higher the compressive strength. Compressive strength 600k
If gf / cm ² or more, the melting point will be 1500 ° C. or more.

The foamed ceramic molded plate is cast by pouring the slurry into a mold, pressure-molded, cured for a predetermined time, and then fired. The firing temperature is 700 to 1300 ° C., which varies depending on the melting point depending on the type of ceramic composition containing the material to be the flux used. The hollow ceramic fine particles are joined at points and firmly bonded together. A ceramic composition containing a material serving as a flux is melted and the ceramic fine hollow particles are fixed to each other by this melt. However, the ceramic fine hollow particles must not be melted at the time of sintering, and the strength must not be reduced by heating. Therefore, the melting point of the hollow ceramic fine particles must be 1500 ° C. or higher.

As described above, the ceramic fine hollow particles used in the present invention are 40 to 45% alumina and 50% silica.
６０60%, and other 1.5-2.5% of a composition formed by foaming. Its physical properties are compressive strength of 700 kgf.
/ Cm ² , melting point 1600-1800 ° C, bulk specific gravity 0.3-
0.5 g / cm ³ , thermal conductivity 0.1 (kcal / mhr)
° C) and consists only of completely hollow particles. The particle diameter of the ceramic fine hollow particles is in the range of 12 to 350 μm, fine 12 to 75 μm, medium 75 to 150 μm.
m and coarseness of 150 to 350 μm. The bulk specific gravity is heavy for fine particles and light for rough ones. For this reason, the range of bulk specific gravity is 0.3 to 0.5 g.
/ Cm ³ .

To the flux of the present invention, one or more of feldspar, limestone, magnesium carbonate, lime phosphate, lead oxide, boric acid, borax, sodium carbonate, sodium nitrate, zinc oxide and the like are added. What is ceramic composition B ₂ O
₃ , SiO ₂ , GeO ₂ , ZrO ₂ , P ₂ O ₅ , As ₂
O ₅ , Sb ₂ O ₃ , Bi ₂ O ₃ , P ₂ O ₃ , Sb
₂ O ₅ , SO ₃ and other acidic oxides are added to Na ₂ O, K ₂ O,
Basic oxides such as CaO and MgO, Al ₂ O ₃ and Fe
₂ O _3, ZnO, PbO, include those obtained by adding like TiO _2. For example _{SiO 2 -Na 2 O-B 2} O 3, S
_{iO 2 -Na 2 O-CaO,} SiO 2 -K 2 O-Ca
_{O, Al 2 O 3 -SiO 2} -Na 2 O-CaO-B 2 O
₃ , Al ₂ O ₃ —SiO ₂ —TiO ₂ —CaO—B ₂ O
_{3, CaO-SiO 2 -Al 2} O 3 -Fe 2 O 3, Si
O ₂ -Al ₂ O ₃ -K ₂ any one or more or / or natural materials kaolin O etc., plastic clay (Gairome clay, kibushi clay, ball clay, etc.), sericite, pottery stone , Wax stone, bentonite, silica stone, chamotte, feldspar,
Any one kind or two or more kinds of limestone, magnesite, dolomite, wollastonite, talc, bone ash, etc. may be mixed and used.

The fine ceramic particles have fine, medium, and coarse particle sizes adjusted, and 10 to 300 parts by weight of a ceramic composition containing a material serving as a flux is added to 100 parts by weight. If the amount of the ceramic composition containing the material serving as the flux is 5 parts by weight or less, sufficient bonding cannot be achieved and the bonding strength between the ceramic fine hollow particles cannot be increased. On the other hand, if the amount is more than 300 parts by weight, the amount of the melt in the foamed ceramic molded plate is too large, so that a capillary air flow hole cannot be formed.

The foamed ceramic molded plate is extremely lightweight because the ceramic fine hollows having high strength are joined to each other and this portion is fixed by the welded body of the ceramic composition containing the material serving as a flux. Has a specific gravity of 0.5 to 0.7 g / cm ³ . Also, 10-5 at the time of molding
Since the pressure is applied at 00 kgf / cm ² , the foamed ceramic molded plate is dense and has high strength, and the compression strength is 100 kgf / c.
m ² or more.

The high-strength ceramic fine hollow particles can be completely present in the foamed ceramic molded plate in the form of a hollow body. It was found that there are innumerable capillary-shaped air circulation holes.

Due to the innumerable mesh-shaped capillary air circulation holes, air flows from the surface of the foam ceramic molded plate even at a low air pressure of only about 1 kgf / cm ² . That is, air from the front surface flows not only to the back surface of the foamed ceramic molded plate but also to the four circumferences of the foamed ceramic plate. In particular, in the case of hot air, most of the air flows upward and left and right from the front surface and dissipates from the upper end and the left and right ends of the foamed ceramic molded plate.

Therefore, even if a flame is applied to the surface of the foamed ceramic plate according to the present invention, high-heat air due to the flame flows evenly throughout the foamed ceramic molded plate. Therefore, the rise of the back surface temperature is small, and the whole foam ceramic molded plate acts as a heat radiating plate.

When the foamed ceramic molded plate is placed horizontally and water is dripped on its surface, the dripped water can be immediately absorbed. That is, the water dripped into the capillary-shaped air flow holes which are stretched like a mesh in the foam ceramic molded plate immediately flows and is absorbed. The absorbed water does not immediately penetrate the back surface because it flows horizontally and gradually flows downward. Water flows into the capillary air circulation holes of the foam ceramic molded plate, and the amount of water absorption is almost the same as the weight of the foam ceramic molded plate. Even if the water absorbed by the foamed ceramic molded plate freezes, the expansion pressure is uniformly diffused over the four circumferences, so that cracking does not occur due to freezing.

The foamed ceramic molded plate of the present invention has a compressive strength of 600 kgf / cm ² or more and a bulk specific gravity of 0.3 to 0.
The main constituent material is a ceramic composition containing 5 g / cm ^{3 of} fine ceramic hollow particles having a melting point of 1500 ° C. or higher and a material that serves as a flux. In addition to this, an aqueous binder and water are added to improve the properties as necessary. For the purpose of dispersion, various surfactants, admixtures such as antibacterial / antifungal agents, thickeners and stabilizers, and inorganic extender pigments may be used.

As the slurry-like colored inorganic pigment for spray-coloring the ceramic fine hollow particles for coloring the foamed ceramic molded plate, glaze powder, feldspar powder, frit powder, zirconium silicate and / or copper oxide, cobalt oxide,
A mixture of metal oxides such as iron oxide, manganese oxide, nickel oxide, and chromium oxide added and mixed can be used by mixing with water or a solvent. Spray coloring is applied to the entire surface of the ceramic fine hollow particles and dried.

[0028]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be described below in detail, but the present invention is not limited to the embodiments unless it exceeds the gist.

[Example] Compressive strength is 700 kgf / cm ² , bulk specific gravity is 0.3 to 0.5 g / cm ³ , melting point is 1600 ° C., and thermal conductivity is 0.1 (kcal / mhr ° C.). 100 parts by weight of the ceramic fine hollow particles and 30 parts by weight of the ceramic composition containing the material to be the flux are mixed with 1.2 parts of a dispersant, a thickener, a stabilizer, etc. as an admixture.
2 parts by weight of water-based binder and 4 parts of water
The composition containing 0 parts by weight was sufficiently kneaded and then cast into a mold to form a plate, which was pressure-molded at a pressure of 300 kgf / cm ² . After pressure molding, it was aged at room temperature for 60 minutes and fired at 1100 ° C. for 45 minutes to prepare a foam ceramic molded plate.

The size of the foam ceramic molded plate is 400 × 6.
It is 00 × 30 mm. The fine ceramic particles used were fine-grained 10 parts by weight, medium 20 parts by weight, and coarse 30 parts by weight. Polyethylene glycol was used as the aqueous binder. The ceramic composition containing the material to be the flux is SiO ₂ —Na ₂ O—CaO.
A glass powder consisting of 10 parts by weight each of kaolin and ball clay was added to 100 parts by weight, and 10 parts by weight each of borax and feldspar were added as a flux.

Comparative Example 1 Comparative Example 1 Shirasu balloon (manufactured by S Co.) was used in place of the ceramic fine hollow particles used in the actual printing example. Others are exactly the same as the embodiment.

Comparative Example 2 Instead of the ceramic fine hollow particles used in the examples, glass balloons (manufactured by A company) were used. Others are the same as the actual example.

Table 1 shows a comparison of various physical properties of Examples and Comparative Examples 1 and 2. Each of the produced specimens is 400
It is x600x30 mm. The specific gravity of the foamed ceramic molded plate according to the present invention is 0.60 because the fine ceramic hollow particles are not broken at all, which is extremely lightweight. Originally, the hollow hollow foam of Shirasu balloon was 1/3 in weight and 1/2 in volume, and most of it was destroyed by the pressure molding, so that the specific gravity was 1.78, which was very heavy. It can be said that the glass balloon was destroyed by about 60% and became heavier.

[0034]

[Table 1]

The compressive strength is the highest in the example, and in the comparative example, the bonding due to the ceramic composition containing the material serving as the flux due to the fracture of the balloon is not complete and sufficient strength cannot be expressed. When air is applied at a pressure of 1 kgf / cm ² from the front surface to the back surface of the foamed ceramic molded plate, the result of a test as to whether or not air permeates from the front surface to the back surface,
Only the example was permeated, and the comparative example did not permeate air because the microscopic air passage holes of the microcapillary shape were not formed inside due to the destruction of the balloon.

The water absorption of each test piece and the results of the water permeability test from the front surface to the back surface are shown by weight ratio. The actual rotation example shows that up to 130% of the weight of the foamed ceramic molded plate is absorbed, and when 115% of water is absorbed, water from the front surface oozes out to the back surface.
In each of the comparative examples, water permeability was not possible because fine capillary-shaped air flow pores in the micron unit were not formed in the molded product and it was an incomplete foam.

The flame front of a gas burner was applied to each sample, and the temperature of the back surface was measured. The tip of the gas burner is about 12
Flame irradiation time at 00 ° C. is 10 minutes. In the case of actual rotation, the air raised by the flame spreads throughout the foam ceramic molded plate and the temperature rise on the back surface is extremely low.

[0038]

As described above, the foamed ceramic molded plate according to the present invention is made of fine micro-capillary particles of micron unit which are made lightweight by using high strength ceramic fine hollow particles and have high strength and allow air to flow therethrough. The air circulation holes are stretched like a mesh. The foamed ceramic molded plate penetrates air but does not penetrate water and has a very high water absorbing performance, and the absorbed water does not seep outside and evaporates naturally. Therefore, even if the foam ceramic molded plate is placed horizontally and water is dropped from the front surface, the saturated water absorption amount of the foam ceramic molded plate does not drip from the back surface. Further, it is an excellent foamed ceramic molded plate which has excellent heat insulating properties and has a very low temperature rise on the back side against a flame, and can be suitably used not only for various building members but also for filters, diffuser plates and the like.

Claims (2)

[Claims] 1. A ceramic composition component 10 containing 100 parts by weight of ceramic fine hollow particles having a compressive strength of 600 kgf / cm ² or more, a bulk specific gravity of 0.3 to 0.5 g / cm ³ , and a melting point of 1500 ° C. or more, and a material serving as a flux. ˜300 parts by weight of the composition is kneaded, placed in a mold and pressure molded 700 to 1
A foamed ceramic molded plate, which is fired at 300 ° C. 2. A colored foamed ceramic molded plate is characterized by using colored ceramic fine hollow particles obtained by spraying and drying slurry-like colored inorganic pigment on the ceramic fine hollow particles according to claim 1. The foamed ceramic molded plate according to claim 1.