JP2010532299A - Foamed ceramic having excellent heat insulating effect and soundproofing effect and method for producing the same - Google Patents

Abstract

  The present invention relates to a ceramic slurry formed by mixing foam, silicate, ceramic powder, and additive in which fine bubbles are formed by a foaming agent diluted with water, and is introduced into the ceramic slurry. A foamed ceramic comprising a gelling agent that maintains the shape of the gel and forms a three-dimensional silica network is provided. The foamed ceramic is formed by diluting a foaming agent with water and forming a large amount of fine bubbles using a foaming apparatus containing a foaming agent diluted with water, and the resulting foam has a silicate, ceramic powder, and Additives are mixed to form a ceramic slurry, a gelling agent is introduced into the ceramic slurry to maintain the shape of the ceramic slurry to form a three-dimensional silica network, and the ceramic slurry is dried to remove internal moisture. Thus, the additive is fused to increase water resistance.

Description

  The present invention relates to a ceramic foam excellent in heat insulation effect and sound insulation effect, and a method for producing the same. More specifically, a plant foam or animal foam is added to an aqueous solution and foamed, and a ceramic powder, a silicate, and an additive are added thereto to produce a microporous ceramic slurry, and a three-dimensional silica network. The present invention relates to a foamed ceramic in which a large amount of fine foam is formed by maintaining a foamed shape through a gelation process to form a foam and drying and curing the foam.

  In general, in order to prevent energy from being wasted due to heat flowing in and out of the building through the outer wall of the building during the construction of the building, heat insulation is performed such as installing a heat insulating material on the outer wall of the building. Further, the heat insulating material serves as a soundproofing material, and plays a role of reducing life discomfort due to noise.

  Bubbles formed at the time of foaming are extremely excellent in heat insulation effect and sound absorption effect. Therefore, in order to maximize the heat insulation effect, a ceramic with a porous structure or a foamable polymer material has been used alone. In order to enhance the soundproofing effect, a sound absorbing material is added to a porous ceramic containing an air layer.

  Conventional insulation and soundproofing materials are expanded polystyrene, glass wool, expanded polyethylene, polyurethane foam, vermiculite, perlite, urea foam, cellulose insulation, soft fiberboard, phenolic foam, aerogel, and Lightweight cement is used.

In the case of expanded polystyrene, the heat insulation effect is high and light weight, so it is excellent in transportation and workability, but the maximum safe use temperature is as low as 70 ° C, it is weak to ultraviolet rays, and there is a risk of ignition and generation of toxic gas in the event of a fire. There was a problem that it was dangerous and could be fatal to the human body. In glass wool, an air layer sealed between glass fibers acts as a heat insulation layer, and in addition to heat insulation, it is excellent in nonflammability, sound absorption, workability, and transportability, and has an effective thickness due to compression and settlement. Although there is no fear of a decrease or a decrease in heat insulation due to water content, there is a problem that it is necessary to provide a moisture-proof layer separately because of no moisture resistance. Polyethylene foam is made of polyethylene resin by adding a foaming agent and a flame retardant, extruded and foamed, and then laminated with a cooled plate-like foaming agent (or foamed sheet), and heat-sealed to maintain heat-extinguishing properties. It is manufactured to a board and a heat insulating cylinder. The thermal conductivity at average temperature is 0.039 kcal / mh ° C or less, so heat insulation effect is excellent, but the maximum safe use temperature is 80 ° C, and toxic gas released in the event of a fire is fatal to the human body. There is a disadvantage that it can. Polyurethane is an insulating material and soundproofing material of an organic foam (closed cell structure), and is obtained by foam molding a polyurethane foam containing polyurethane, polyol, polyisocyanate, and flame retardant additives as main ingredients. . Although heat resistance (maximum safe operating temperature: 100 ° C.) is slightly reduced, it has excellent heat insulation properties, so it is suitable for cold insulation materials such as refrigeration equipment. However, there are disadvantages in that the volume after construction decreases and the thermal conductivity decreases. Also, like other foamable polymer materials, there is a problem of releasing toxic gas in the event of a fire. Meteorite is a porous inorganic material obtained by firing mica-based ore at a temperature of 1,000 ° C. or higher, and is excellent in heat insulation, heat retention, nonflammability, soundproofing, and prevention of condensation. Pearlite is obtained by firing pearlite made of volcanic stone at 900-1200 ° C. and then crushing it to plastically expand to form lightweight spherical particles with fine pores inside. And used as a heat insulating material. Meteorite and pearlite are effective for heat insulation, heat retention, and sound absorption, but there is a problem that high energy of 1000 ° C. or higher is required to foam minerals such as meteorite and pearlite. Airgel is extremely superior in heat insulation and soundproofing because fine structures with a thickness of 1 / 10,000 of the hair are entangled with each other like cotton candy and the pores account for 95% of the total volume. There are advantages. However, since it is very expensive, it is only used in some industries. Since lightweight cement uses an inexpensive cement as a binder, it can provide an economical foam material. However, hexavalent chromium (Cr ⁶⁺ ) contained in cement may cause respiratory diseases and carcinogenesis. In addition, in order to produce lightweight cement, it must be cured in a high-temperature and high-pressure reactor (autoclave), which not only has an economic burden on installation costs but also high thermal energy to cure the foamed cement. In addition, there is a problem that it takes a long time to cure the cement.

  Petrochemical products have been developed and used as heat insulating materials and sound insulation materials to date. However, not only is there a very high risk of lethal damage to the human body due to the release of toxic gas in the event of a fire, but it may also cause environmental pollution. Foamed ceramics and lightweight cements require a large-scale equipment system and require a high-temperature treatment process or a long-time treatment process, resulting in a problem of large energy loss and reduced productivity.

  In particular, the foamed ceramic is molded in a predetermined mold for compression molding, and therefore expensive equipment is required, and expensive raw materials such as airgel must be used. For this reason, since price competitiveness falls, it is applied restrictively in fields, such as a heat insulating material for buildings, and a soundproofing material.

  In order to solve the above problems and to provide a porous lightweight structure as a heat insulating material and a soundproofing material, Korean Patent Application Publication No. 2006-0099979 describes liquid sodium silicate with acid, amphoteric oxide, or amphoteric hydroxide. There has been proposed a method of manufacturing a ceramic foam molded product as a structure in which a medium hole portion is formed inside by using incompletely gelled sodium silicate produced by adding a product as a binder. However, although it is possible to reduce the weight of the foamed molded article to increase the sound absorption, sound insulation, and heat insulation properties, it is possible to use an incompletely gelled sodium silicate, which is a colloidal substance, as a binder. The technological advance is not significant because it is merely the production of ceramic foam moldings.

  Also, in Korean Patent Publication No. 2006-098782, various foamed ceramic particles including pulverized meteorite, pearlite, obsidian, pine stone, gypsum, cement, paper clay, sodium silicate, incomplete gel silicate Manufactured by mixing one or more inorganic adhesives including soda, sodium silicate cement, etc., and other reinforcing materials such as steel fibers, fiber scraps, paper scraps (including powders), and glass wool. Alternatively, a method of providing a ceramic foam molded article with enhanced durability by installing a metal mesh or a synthetic resin mesh inside has been proposed. However, although it can provide heat insulation to the air layer contained in the ceramic, natural rocks such as meteorite, pearlite, obsidian and pine stone are made to the desired size to produce the foamed ceramic. Since the pulverized particles must be heated at a high heat of 800 to 1400 ° C., a large amount of heat energy is required for the production of the foamed ceramic, and the equipment cost for the production is high. And the technical progress is not so great because it is only mixed with inorganic adhesives such as gypsum, cement, paper clay, sodium silicate, incompletely gelled sodium silicate, sodium silicate cement, etc. .

  In addition, in US Patent Publication No. 2006-0151903, silicate is a main component, and in order to impart porosity, oxygen, nitrogen, air, carbon monoxide, carbon dioxide is injected as a carrier gas to form foam ( Techniques for forming foam) are disclosed. However, the target substance is not specifically proposed like ceramic foaming, but a carrier gas such as oxygen, nitrogen, air, carbon monoxide and carbon dioxide is simply blown into the silicate-containing medium. , A technology that utilizes an inorganic binder to form a foam. Since this technology requires large-scale equipment, it is difficult to actually apply it to industries for economic reasons.

Korean Patent Publication No. 2003-0086955 discloses a non-flammable lightweight aerated concrete sandwich panel as a finishing material for the outer wall of a building in consideration of heat insulation. More specifically, a natural meteorite is heated at a high temperature to adjust the air density to about 40 to 50 kg / cm ² by using an expanded meteorite in which pores are formed and a lauryl alkylbenzene sulfonate-based material. The resulting foam, cement slurry and expanded meteorite are mixed to obtain a non-flammable lightweight aerated concrete sandwich panel that does not burn in the event of a fire and does not release toxic gases. However, the surfactant can provide excellent foaming power and can improve the economy by using cement as an inorganic binder. It has the disadvantage that productivity is very poor because it requires it.

  The present invention has been made to solve the above-described problems of the prior art. An object of this invention is to provide the foaming ceramic which can substitute the foaming resin which is a petrochemical product utilized conventionally as a heat insulating material and a soundproofing material, and its manufacturing method.

  The present invention also provides a foamed ceramic that does not release a toxic gas in the event of a fire through a gelation step in which ceramic powder and a foaming agent are mixed to form a three-dimensional silica network, and a method for manufacturing the same. Objective.

  Another object of the present invention is to provide a foamed ceramic containing a large amount of fine bubbles that can be produced without going through a high-temperature process, and a method for producing the same.

  The present invention relates to a ceramic slurry formed by mixing a foam, silicate, ceramic powder, and additives in which fine bubbles are formed by a foaming agent diluted with water, and the ceramic slurry is supplied to the ceramic slurry. A foamed ceramic comprising a gelling agent that maintains the shape of the gel and forms a three-dimensional silica network is provided.

  According to another aspect of the invention, the foaming agent is diluted at a weight ratio of 100: 0.1 to 10 with respect to water.

  According to another aspect of the present invention, the foaming agent is selected from among amino acid-based animal foaming agents, vegetable foaming agents containing an alkylbenzene sulfonate-based material, sodium lauryl sulfate, or an ester thereof as an active ingredient. .

  According to another aspect of the invention, the silicate is included in a weight ratio of 100: 20 to 160 with respect to the ceramic powder.

  According to another aspect of the invention, the ceramic slurry has a viscosity of 5000-200000 cps.

  According to another aspect of the present invention, the silicate contained in the ceramic slurry includes one to four types of solution-type sodium silicate, powder-type sodium silicate, potassium silicate, lithium silicate, silica Selected from sodium aluminum oxide.

  According to another embodiment of the present invention, the ceramic powder contained in the ceramic slurry may be barley stone, ocher stone, olivine, Kaolin, silicate mineral (Silica Minerals), magnesite (Magnesite). ), Bauxite, bentonite, pumice, borate, serpentine, acid clay, iron oxide, garnet, carbonate Carbonate Minerals, Attapulgite, Sepiolite, Nephrite, Apatite, Mite, Illite-Mica, Feldspar, Pearlite, Vermiculite ), Zeolite (Zeolite), barite, talc (Talc), diatomaceous earth, graphite (Graphite), hectorite, clay mineral (Clay Minerals), zirconium mineral (Zirconium Minerals), Titanium Minerals, Tourmaline, Hugh Silica (Fume Silica), airgel (Airgel), fly ash (Fly ash), it is selected from blast furnace slag powder.

  According to another embodiment of the present invention, the ceramic powder has a particle size of 5 nm to 400 μm.

  According to another aspect of the invention, the additive mixed with the ceramic slurry comprises natural fibers or man-made fibers.

  According to another aspect of the invention, the fiber has a thickness of 3 to 50 μm.

  According to another aspect of the invention, the fiber length is 1-50 mm.

  According to another aspect of the present invention, the additive mixed in the ceramic slurry is any one of a water dispersible polymer resin and a fine powder polymer resin for water resistance and reinforcement of the foamed ceramic. including.

  According to another aspect of the present invention, the water dispersible polymer resin is selected from acrylic, vinyl acetate, alkyd, melamine resin, and styrene butadiene rubber solution.

  According to another aspect of the present invention, the fine powder polymer resin is made of polyethylene terephthalate (PET), low density polyethylene, high density polyethylene, vinyl chloride resin (PVC), polymethyl methacrylate (PMMA), polystyrene (PS). ), Polypropylene (PP), ethylene vinyl acetate (EVA), polyurethane (PU), polycaprolactone (Polycarprolacton).

  According to another aspect of the invention, the gelling agent is selected from carbon dioxide gas, dry ice, bicarbonate, glyoxal, ethylene glycol diacetate, organic acid, inorganic acid.

  According to another aspect of the invention, the gelling agent is included in stoichiometic equivalence to silicate.

  According to another aspect of the invention, the bicarbonate is selected from sodium bicarbonate, potassium bicarbonate, ammonium bicarbonate.

  According to another aspect of the invention, the organic or inorganic acid is selected from hydrochloric acid, nitric acid, sulfuric acid, phosphoric acid, hydrofluoric acid, formic acid, acetic acid, citric acid, maleic acid, oleic acid.

  In addition, the present invention is obtained in a first stage in which a foam agent is diluted with water, a second stage in which a foam agent diluted with water is formed using a foaming device, and a large amount of fine bubbles is formed. A third stage in which a silicate, ceramic powder, and additives are mixed into the foamed product to form a ceramic slurry, and a gelling agent is added to the ceramic slurry to maintain the shape of the ceramic slurry to form a three-dimensional silica network. Provided is a method for producing a foamed ceramic comprising: a fourth stage to be formed; and a fifth stage in which the ceramic slurry is dried to remove internal moisture and the additive is fused to increase water resistance. To do.

  According to another aspect of the present invention, in the second stage, the foaming agent is rotated at a speed of 500 to 12,000 rpm in the foaming apparatus including the rotating blades to disperse the foaming agent at a high speed, thereby producing a large amount of fine particles. Bubbles are formed.

  According to another aspect of the present invention, in the second stage, fine bubbles are formed using a compressed gas in a foaming apparatus including a compressor.

  According to another aspect of the present invention, in the third stage, a foam, silicate, ceramic powder, and additives are mixed in a foaming apparatus to form a ceramic slurry.

  According to another aspect of the invention, the fourth stage comprises a gelling agent selected from carbon dioxide gas, dry ice, bicarbonate, glyoxal, ethylene glycol diacetate, organic acid, inorganic acid; A ceramic slurry is mixed to form a three-dimensional silica network.

  According to another aspect of the present invention, the fifth stage is dried by a method selected from room temperature drying with air, hot air drying with an oven, and heat drying using ultra high frequency (UHF).

  According to another aspect of the present invention, hot air drying by an oven or heat drying using ultra-high frequency is performed at 80 to 250 ° C.

  According to another aspect of the invention, the third step forms the ceramic slurry such that the ceramic slurry has a viscosity of 5,000 to 200,000 cps.

  According to another aspect of the invention, the fourth stage introduces a stoichiometric equivalent of gelling agent to the ceramic slurry with respect to the silicate.

  According to another aspect of the present invention, the additive is selected from a water-dispersible resin or a finely powdered polymer resin for water resistance and reinforcement of the foamed ceramic, and the step of improving the water resistance is water. A dispersible resin or a fine powder polymer resin is fused.

  The method for producing a ceramic foam of the present invention includes a first step of diluting a foaming agent with water, and a second step of forming a large amount of fine bubbles using a foaming apparatus containing a foaming agent diluted with water. In the third step, the foam obtained in the second step is mixed with a silicate, ceramic powder, and a water-dispersible resin or fine powder polymer resin as an additive to form a ceramic slurry in a foaming apparatus. A stoichiometric equivalent of silicate with a gelling agent selected from carbon dioxide gas, dry ice, bicarbonate, glyoxal, ethylene glycol diacetate, organic acid, inorganic acid in the ceramic slurry; Introduced in step 4 to maintain the shape of the ceramic slurry to form a three-dimensional silica network, and drying the ceramic slurry to remove the moisture inside the water-dispersible resin or fine powder To provide a method for manufacturing a ceramic foam, characterized in that it comprises a fifth step of increasing the water resistance by fusing the molecules resin.

  Since the foamed ceramic produced according to the present invention is produced at a low temperature and does not require expensive equipment, productivity and economy are improved.

  The ceramic foam produced by the present invention is cured while maintaining the foamed foam shape even at room temperature, and a large amount of fine foam is uniformly formed, which is excellent in heat insulation effect and soundproofing effect.

  The present invention provides a foamed ceramic in which a large amount of fine bubbles are formed in various shapes, and a method for producing the same. The foamed ceramic manufactured according to the present invention has a high heat insulating effect and a soundproofing effect, and is less likely to generate a toxic gas in the event of a fire. Therefore, it is possible to reduce human life damage due to a toxic gas during a fire. Moreover, it is a simple manufacturing process, the production cost is low, and environmental pollution during manufacturing can be greatly reduced.

  In addition, the foamed ceramic manufactured according to the present invention does not require high heat during the manufacturing process, and the equipment cost can be reduced. Further, since the ceramic slurry in the production stage of the foamed ceramic maintains an appropriate level of viscosity, the ceramic slurry is allowed to flow into a predetermined mold and cured to produce a foamed ceramic having a desired shape.

  In addition, the foamed ceramic produced according to the present invention has a low density because a large amount of fine bubbles are foamed, so that it can be reduced in weight and is useful as a heat insulating material and a sound absorbing material.

It is process drawing which shows the manufacturing method of the foam ceramic which concerns on one Example of this invention. 3 is a photograph of a test for water resistance by immersing a foam ceramic according to an embodiment of the present invention in water for 30 days.

Hereinafter, the present invention will be described in more detail with specific application examples.
The foaming agents that can be used at the stage of preparing the foam are amino acid foams called animal foams, alkylbenzine sulfonate materials or vegetable laurate sodium lauryl sulfate, and esters thereof as active ingredients. It is possible to use a foaming agent containing each of them individually or mixed and diluted with water. Here, water is tap water, groundwater, industrial water, etc., except for water containing a large amount of alkaline earth metal that can react with silicate at the following mixing stage and can have a relatively low binding force. Anything can be used without limitation. In order to maintain the foamed state for a long period of time without bubbles being defoamed, it is sometimes preferable to use an animal foam. On the other hand, in order to avoid the odor generated from the foaming agent during the bubble formation process, it is preferable to use a vegetable foaming agent in some cases.

  The amount of the foaming agent added is preferably 0.1 to 10 parts by weight, more preferably 0.25 to 8.5 parts by weight, and most preferably 0.5 to 7.5 parts by weight with respect to 100 parts by weight of water. It is. When the foaming agent is contained in an amount of 0.1 parts by weight or less, the foaming power is low, so that it is difficult to form fine porous bubbles. On the other hand, when the amount of the foaming agent exceeds 10 parts by weight, a large amount of fine bubbles can be formed. However, since the foaming agent is composed of an organic material, the binding force with the ceramic powder is reduced and a fire occurs. A large amount of toxic gas may be generated due to thermal decomposition of the foaming agent.

  For the step of foaming the solution in which the foaming agent is diluted with water, any method may be used as long as a large amount of fine bubbles can be generated. In general, the foaming step is performed by a foaming device, which generates bubbles using a method of foaming by rotation of a rotating blade, a foaming method using a foamer equipped with a compressor, or the like. When a small amount of air bubbles is required, it is advantageous to use a rotary blade. When a large amount of air bubbles is required, it is advantageous to use a foamer equipped with a compressor.

  When using a rotary blade mounted on the shaft of the motor, the rotational speed is in the range of 500 to 12,000 rpm. As an example of a foaming apparatus having such a rotating blade, a mixer, a dissolver (Dissolver), and a homomixer (Homomixer) can be used. A foaming device such as a foamer equipped with a compressor can form a large amount of uniform and fine bubbles, and by adjusting the density of bubbles generated by applying air pressure from the compressor, The degree can be adjusted.

  As the step of forming the ceramic slurry, any method may be used as long as the bubbles formed in the foaming step are not defoamed and the ceramic powder, the silicate, and the additive can be mixed uniformly. For example, the foam, ceramic powder, silicate and additives can be uniformly mixed in a mixer so as to maintain a slurry state. The silicate is preferably mixed in an amount of 20 to 160 parts by weight, more preferably 40 to 140 parts by weight, and most preferably 60 to 110 parts by weight with respect to 100 parts by weight of the ceramic powder. When silicate is mixed in an amount of 20 parts by weight or less with respect to 100 parts by weight of ceramic powder, the bonding strength of the silica network is lowered even after the gelation step to form a three-dimensional silica network, and the foamed ceramic is in a slurry state. May return. On the other hand, when 140 parts by weight or more of silicate is mixed, it is possible to form a foamed ceramic having excellent silica network binding force, but there is a disadvantage in that the production unit price increases due to the addition of an excessive amount of silicate. .

  Here, the state of the ceramic slurry is preferably maintained at a viscosity of 5,000 to 200,000 cps, more preferably 15,000 to 180,000 cps, and most preferably 35,000 to 160,000 cps. When the viscosity of the ceramic slurry is 5,000 cps or less, there is a disadvantage that the possibility of defoaming the ceramic slurry that is low in viscosity and finely foamed is high. On the other hand, if the viscosity is 200,000 cps or more, the fluidity is too low, so when forming the foamed ceramic by flowing into the mold, the ceramic slurry does not flow well into the corners of the mold, etc. There is a problem that it is not possible to make a foam ceramic of the shape.

On the other hand, any silicate may be used as long as it has a property of being dissolved in water or uniformly dispersed. Usable silicates are one or more selected from one to four types of solution-type sodium silicate, powder-type sodium silicate, potassium silicate, lithium silicate, and sodium aluminum silicate. It is preferable to be mixed. Potassium silicate and lithium silicate, when forming a foam ceramic, can provide a foam ceramic with excellent bonding strength and water resistance, but are expensive. In contrast, sodium aluminum silicate has the advantage of being relatively inexpensive, but since the silica content is relatively less than the aluminum content, the bonding strength is somewhat reduced. Further, in order to dissolve the powdered sodium silicate in water, a heat source or long-time dissolution is required. Sodium silicate type I (SiO ₂ / Na ₂ O, molar ratio: 2.1 to 2.3) is one of four types of aqueous solutions of sodium silicate and has a very high viscosity of 100,000 cps or more. Therefore, water must be supplied in order to adjust the state of the slurry, and there is a disadvantage in that the adhesive force or bonding force may be reduced. Further, when manufactured in winter, there is a disadvantage that it is easy to solidify like ice and workability is lowered. Sodium silicate type II (SiO ₂ / Na ₂ O, molar ratio: 2.4 to 2.6) contains more silica sol than sodium silicate type I, but has a viscosity of 10,000 to 50,000 cps. Due to its high cost, sodium silicate type II has the same disadvantages as sodium silicate type I. Sodium silicate type III (SiO ₂ / Na ₂ O, molar ratio: 3.15 to 3.30) is not high in viscosity, so that ceramic mineral can be easily adjusted to a slurry state and inexpensive. There are advantages. Sodium silicate type IV (SiO ₂ / Na ₂ O, molar ratio: 3.4 to 3.6) is capable of producing a large amount of silica network and has a relatively low viscosity, so that the ceramic mineral is in a slurry state. However, there is a disadvantage that the unit price is high.

  Ceramic powders are barleystone, ocher stone, olivine, high-grade clay, silicate mineral, magnesite, bauxite, bentonite, pumice, borate, serpentine, acid clay, iron oxide, stone meteorite, carbonate Mineral, attapulgite, sepiolite, soft jade, apatite, illite (mica), feldspar, nacre, meteorite, zeolite, barite, talc, diatomaceous earth, graphite, hectorite, clay mineral, zirconium mineral, titanium mineral, tourmaline, fume One or more of silica, aerogel, fly ash, and blast furnace slag powder may be mentioned, but not limited thereto.

  The size of the ceramic mineral particles is preferably small so that fine bubbles are formed between the ceramic particles, but particles having a size of 5 nm to 400 μm can be used. Preferably they are 20 nm-250 micrometers, Most preferably, they are 5 nm-50 micrometers. When particles of 5 nm or less are used, it is difficult to produce using a general pulverizer except for airgel, and the cost for pulverizing the particles is not preferable. Further, when particles of 400 μm or more are used, the surface area of the ceramic powder is small, and the adhesive force is reduced at the gelation stage, and it is difficult to form fine bubbles between the particles.

  The additive may include a sound-absorbing material that also serves as a strength reinforcing agent to increase the strength of the foamed ceramic, and a water-resistant reinforcing agent for increasing water resistance. In general, a metal oxide or a fiber can be used as a sound absorbing material that also serves as a strength reinforcing agent. In the case of a metal oxide, since the foamed ceramic is made of a metal oxide, it is not necessary to add it artificially. When the fibrous sound absorbing material is added and the fibers are filled between the ceramic particles, not only the adhesive force is increased but also the soundproofing effect is improved.

  Since the foamed ceramic is formed at room temperature, the strength reinforcing agent may be either a natural fiber or an artificial fiber as long as it is composed of a fiber to increase the strength of the foamed ceramic. For example, cellulosic fibers (seed fibers, bast fibers, leaf fibers, fruit fibers), protein fibers in staple form or filament form, mineral fibers, etc. are used as natural fibers, and organic fibers are organic. Examples include, but are not limited to, fibers (regenerated fibers, semi-synthetic fibers, synthetic fibers, etc.) or inorganic fibers (metal fibers, glass fibers, rock fibers, slag fibers, carbon fibers, etc.).

  The thickness of the fiber of the inhalation material that also serves as a strength reinforcing agent is preferably 3 to 50 μm, more preferably 5 to 25 μm, and most preferably 5 to 10 μm. Due to the properties of the fiber, the thinner it is, the smoother the appearance and the softer the tactile sensation, and the superior physical properties make it highly useful, but it is produced with natural fibers and artificial fibers other than glass fibers. Most of the fibers have a thickness of 3 μm or more, and it is not easy to select a fiber having a thickness of 3 μm or less. On the other hand, fibers having a thickness of 50 μm or more are disadvantageous in that the appearance is not smooth and the strength decreases.

  Further, the length of the fiber of the sound absorbing material that also serves as the strength reinforcing agent is preferably 1 to 50 mm, more preferably 5 to 35 mm, and most preferably 10 to 25 mm. When the length of the fiber is 1 mm or less, the fibers connected between the fine porous ceramic particles of the three-dimensional silica network in the gelation stage are short, and there is a disadvantage that the adhesive force is not so large, and the length is 50 mm or more. In addition, the fibers are not uniformly mixed with the ceramic in the formation stage of the ceramic slurry, so that the fibers are entangled with each other and the physical properties of the foamed ceramic are deteriorated.

  On the other hand, the amount of the fiber added as the sound absorbing material that also serves as the strength reinforcing agent is preferably 1 to 20 parts by weight, more preferably 2.5 to 15 parts when the ceramic powder is 100 parts by weight. Part by weight, most preferably 5 to 10 parts by weight is included. When the sound absorbing material is contained in an amount of 1 part by weight or less, there is almost no effect of reinforcing the foamed ceramic, and when it is contained in an amount of 20 parts by weight or more, it is difficult to mix with the ceramic powder or the fiber.

  On the other hand, a water dispersible polymer resin or a fine powder polymer resin can be added as the water-resistant reinforcing agent. In the case of a water-dispersible polymer resin, any resin can be used as long as it is uniformly mixed with water. Examples of the water-dispersible polymer resin include water-dispersible acrylic, vinyl acetate, alkyd, melamine resin, and styrene butadiene rubber solution (Solution Styrene Butadiene Rubber). The amount of the water dispersible polymer resin added is preferably 1.0 to 25 parts by weight, more preferably 2.5 to 25 parts by weight, and most preferably 5 to 10 parts by weight based on 100 parts by weight of the ceramic powder. Parts by weight. When 1 part by weight or less is added, there is a disadvantage that a polymer film cannot be sufficiently formed between the ceramic foam particles and the water resistance is not large. When added in an amount of 25 parts by weight or more, the water resistance greatly increases, but there is a disadvantage that a large amount of toxic gas is generated due to decomposition of the polymer in the event of a fire, which can be fatal to the human body.

  Fine powder polymer resin includes polyethylene terephthalate (PET), low density polyethylene, high density polyethylene, vinyl chloride resin (PVC), polymethyl methacrylate (PMMA), polystyrene (PS), polypropylene (PP), ethylene vinyl acetate (EVA), polyurethane (PU), polycaprolactone, and the like, but are not limited thereto. The fine powder polymer resin preferably contains 0.5 to 15 parts by weight, more preferably 2.5 to 12 parts by weight, and most preferably 5 to 10 parts by weight, when the ceramic powder is 100 parts by weight. is there. When 0.5 parts by weight or less is contained, there is a disadvantage that a polymer film cannot be sufficiently formed between the ceramic foam particles, and the water resistance is not large. When added in an amount of 15 parts by weight or more, the water resistance is greatly increased, but there is a disadvantage that a large amount of toxic gas is generated due to decomposition of the polymer in the event of a fire, which can be fatal to the human body.

  The smaller the particles of the fine powder polymer resin, the better. However, the range of 0.5 μm to 0.1 mm is preferable, the range of 0.5 μm to 1 mm is more preferable, and the range of 5 to 50 μm is most preferable. If the size of the powder particles is less than 0.1 μm, the surface area becomes large and the possibility of being dispersed in water is high, but there is a disadvantage that the work is not easy due to the dust caused by the fine particles and the economy is reduced. On the other hand, when the thickness exceeds 0.5 mm, the surface area is small and the particles are large, so that there is a problem that the probability of uniform fusion to the ceramic powder is low.

  Further, the gelation step is a step of forming a three-dimensional silica network in the fine-cell ceramic slurry already formed in the foaming step and the slurry forming step. At this stage, the foam of the ceramic slurry is not defoamed and is cured while maintaining the foamed shape, so that a large amount of fine bubbles are formed. Therefore, a high temperature process necessary for the production of the conventional foamed ceramic is not required. Disappear.

A method for forming a three-dimensional silica network is to use a foam in a slurry state containing silicate and ceramic, carbon dioxide (CO ₂ ), acid, bicarbonate source, glyoxal, ethylene It can be formed by mixing or immersing with glycol diacetate.

  When carbon dioxide, dry ice, bicarbonate gas, glyoxal, ethylene glycol diacetate, etc. are uniformly infiltrated into the foamed ceramic slurry, the silicate, carbon dioxide, bicarbonate gas, glyoxal, ethylene contained in the ceramic slurry Reaction with glycol diacetate, etc. causes the chemical balance to be lost in the sol state as shown in Chemical Formulas 1-3, and the particles are entangled with each other to form a three-dimensional silica network by silicate gel development. In addition, the solid state is maintained, and the three-dimensional silica network serves as an inorganic binder to maintain a foamed shape.

Reaction formula 1
M ₂ O · nSiO ₂ + CO ₂ → nSiO ₂ (silica gel form) + M ₂ CO ₃
(M = Na, K, Li) (n = 2-4)
Reaction formula 2
M ₂ O · nSiO ₂ + H ₂ SO ₄ → nSiO ₂ (silica gel form) + M ₂ SO ₄
(M = Na, K, Li) (n = 2-4)
Reaction formula 3
M ₂ O · nSiO ₂ + LHCO ₃ → nSiO ₂ (silica gel form) + M ₂ CO ₃ + LOH
(L = Na, K, NH ₄ ) (M = Na, K, Li) (n = 2 to 4)

  When the source for forming the three-dimensional silica network is carbon dioxide, carbon dioxide gas stored in a gas cylinder or dry ice can be used. When carbon dioxide gas stored in the gas cylinder is used, the amount of carbon dioxide injection can be adjusted arbitrarily by the pressure regulator, and it can be injected at a high pressure. When trying to form the original silica network, it is preferable to use dry ice. However, when dry ice is used as a source, the foam containing moisture may freeze, and if it occurs, the three-dimensional silica network may be damaged or the adhesive strength may be reduced. Care must be taken not to come into direct contact with.

  When the source forming the three-dimensional silica neckwork is an acid, the foam containing the silicate is immersed in the acid diluted with water, or the foam and the acid in the slurry state containing the silicate are used. Can be mixed to form a three-dimensional silica network. When the ceramic slurry is immersed in the diluted acid, when the ceramic slurry is immersed in the diluted acid solution for 2 to 10 seconds, a three-dimensional silica network is formed at the same time as neutralization. This method is suitable for forming a three-dimensional silica network in a ceramic slurry of 1 cm or less because the rate at which the acid penetrates into the finely foamed ceramic slurry is relatively slow.

  When mixing the foam in porous slurry containing silicate and acid, a three-dimensional silica network can be formed within 10 seconds, which is the pH range of the ceramic slurry mixed with acid. Must be 5-9. Moreover, when forming a three-dimensional silica network, when 1 minute or more is requested | required, the pH range of a ceramic slurry may remove | deviate from the range of 5-9. Here, as the acid used, one or more acid mixed solutions of hydrochloric acid, nitric acid, sulfuric acid, phosphoric acid, hydrofluoric acid, formic acid, acetic acid, citric acid, maleic acid and oleic acid can be selected. Preferably, sulfuric acid, acetic acid and citric acid which are inexpensive and can minimize environmental pollution may be used. The acid dilution amount is 2 to 25 parts by weight, more preferably 2.5 to 20 parts by weight, most preferably 4.0 to 15 parts by weight, with the total weight of water being 100 parts by weight. It is said. When the acid is diluted in an amount of 2 parts by weight or less, the gelation is performed while neutralizing the alkaline silicate contained in the foam. When more than part of the acid is diluted, it is difficult to adjust the formation time of the three-dimensional silica network, and the gelation is hindered because there is too much acid, and the excess acid remaining in the foam is dried at the drying stage described later. May cause air pollution and respiratory illness.

  When the source for forming the three-dimensional silica network is bicarbonate, any one selected from sodium bicarbonate, potassium bicarbonate, ammonium bicarbonate, or a mixture may be used. However, a solution of bicarbonate powder or a solution obtained by dissolving bicarbonate in water is mixed with a foamed ceramic slurry, or a foamed ceramic slurry is immersed in a solution of bicarbonate powder in water. Can be used. On the other hand, when using ammonium bicarbonate among bicarbonates, toxic gas from ammonia gas or ammonia water is released after the final reaction, which is harmful to human body and more expensive than sodium bicarbonate, The use of sodium bicarbonate is advantageous both in terms of price and environment. The amount of bicarbonate used is the stoichiometric equivalent that can react with the silicate contained in the foam to cause gelation. When dissolved in water or shaken, uniform gelation can be achieved by forming a uniform three-dimensional silica network.

  When the source is glyoxal and ethylene glycol diacetate, it is suitable when a relatively long time is required to form a three-dimensional silica network. For example, the reaction formula of ethylene glycol diacetate and silicate is as follows.

Reaction formula 4
H ₃ C—COO—CH ₂ —CH ₂ —OCO—CH ₃ (EGDAc) + 2H ₂ O
→ OH—CH ₂ —CH ₂ —OH (EG) + 2CH ₃ COOH (acetic acid)

  The foamed ceramic slurry containing the silicate is cured through a primary reaction and a secondary reaction. The primary reaction is a hydrolysis reaction in which EGDAc (ethylene glycol diacetate) is an alkaline solution in the silicate. In the presence, as shown in Reaction Scheme 4, it is hydrolyzed to produce EG (ethylene glycol) and acetic acid.

Reaction formula 5
M ₂ O · nSiO ₂ + 2CH ₃ COOH
→ 2CH ₃ COOM + nSiO ₂ (silica gel form) + H ₂ O
(M = Na, K, Li) (n = 2-4)

  Next, as shown in Reaction Formula 5, a three-dimensional silica network is gradually formed by the gelation reaction. That is, the silicate reacts with acetic acid to produce sodium acetate and an insoluble silicate gel.

  Furthermore, the heating stage is a water-dispersible polymer resin or fine powder polymer resin that is a water-resistant reinforcing agent for removing water contained in the foamed lightweight ceramic formed up to the gelling stage or improving the water resistance. Is coated on the surface of the ceramic foam of the three-dimensional silica network by thermal fusion. It is possible to remove the moisture in the foamed ceramic without causing a physical change in the foamed ceramic in which a large amount of finely foamed bubbles are formed, and at the same time, the added polymer resin can be fused to the ceramic surface by heat. Any method may be used as long as it is a method. For the foamed ceramic that has undergone the gelation step, a room temperature drying method using air, a hot air drying method using an oven, or a rapid drying method using ultra-high frequency (microwave oven) can be used. The room temperature drying method is suitable for producing a thin foamed ceramic that does not require much water resistance. This is because a wide range of foams are laminated and dried by air, so that the equipment cost required for the drying process can be reduced and heating is not required, so there is no fuel cost, but the drying time is long. For this reason, the space for drying must be increased, and the productivity is low.

  The drying method using ultra high frequency waves is a method in which water molecules are vibrated by applying ultra high frequency waves of 2,450 MHz and water is dried by vibrational heat. This has the advantage that moisture inside the ceramic foam can be removed at a high rate, but if the ceramic foam is thick and large, as in the case of heat insulation, it requires a lot of equipment costs for the ultra-high frequency generation equipment. There is a disadvantage of being.

  The hot air drying method using an oven has an advantage that the foamed ceramic can be dried in a short time with relatively low equipment costs.

  Here, when using an ultra-high frequency or a hot-air drying method, the heating temperature is preferably 80 to 250 ° C, more preferably 90 to 220 ° C, and most preferably 100 to 200 ° C. When heated at a temperature of 80 ° C. or lower, not only the removal rate of water contained until the gelation stage is not so great, but also the water dispersible polymer resin or fine powder polymer resin for improving the water resistance is melted. It is difficult and cannot be fused to the ceramic surface. On the other hand, when the heating temperature exceeds 250 ° C., the moisture can be evaporated at a high speed and the temperature is higher than the melting point of the fine powder polymer resin, so that the polymer resin can be heat-sealed to the ceramic surface in a short time. However, there is a disadvantage that the physical properties of the polymer change at high temperatures.

Hereinafter, the present invention will be described in more detail with reference to preferred embodiments of the present invention.
Example 1
As a foaming agent, an animal foaming agent made by Korea Sangyo Co., Ltd. was added in an amount corresponding to 2% of the weight of water, and a foaming aqueous solution was produced using a homomixer. 250 g of ocher powder is separated and mixed, 150 g of water glass (sodium silicate) type III manufactured by Sanwa Industry Co., Ltd. is mixed, and CMC as a thickener is added so that the viscosity becomes about 100,000 cps. This was added to produce an ocher foaming slurry containing silicate. A CO ₂ gas line was inserted therein, and carbon dioxide gas was purged (purging) for 2 minutes to be gelled and solidified, and heated and dried in an oven at 100 ° C. for 2 hours to produce a foamed ceramic.

Example 2
As a foaming agent, a plant foaming agent (trade name: Informer) manufactured by Hanichi Corn Co., Ltd. was produced in the same manner as in Example 1 except that an amount corresponding to 2% of the water weight was added. .

Example 3
After adding an amount corresponding to 4% of the water weight of the animal foam made by Korea Sangyo Co., Ltd., and producing a foaming aqueous solution using a bubble generating device, here, Toyo Seikan Fume Silica Co., Ltd. 200 g of powder is separated and mixed, 130 g of potassium silicate manufactured by Sanwa Kogyo Co., Ltd. is mixed, CMC as a thickener is added so that the viscosity becomes about 150,000 cps, and silicate is added. A fume silica slurry containing was produced. Add 50 ml of 10% sodium bicarbonate solution and mix uniformly at a very high speed. After mixing, the slurry is gelled and solidified within 13 seconds, heated by ultra high frequency waves for 30 minutes, and then dried. To produce a foam ceramic.

Example 4
An amount of water equivalent to 4% of the weight of water produced by Hanichi Corn Co., Ltd. is diluted in water, and a foaming aqueous solution is produced using a homomixer. 250 g of ocher powder, 150 g of water glass (sodium silicate) type III manufactured by Sanwa Kogyo Co., Ltd., 7.5 g of fibers manufactured by Deantech Korea, water dispersible acrylic resin (emulsion acrylic resin) manufactured by Ogon Bond Co., Ltd. ) 5 g of each was mixed, and CMC as a thickener was added so that the viscosity was about 100,000 cps, and a loess slurry containing silicate was produced. This was immersed in 100 ml of sulfuric acid aqueous solution diluted to a concentration of 10% for 15 seconds to be gelled and solidified, and heated and dried in an oven at 100 ° C. for 2 hours to produce a ceramic foam.

Example 5
An amount of water equivalent to 4% of the weight of water produced by Hanichi Corn Co., Ltd. is diluted in water, and a foaming aqueous solution is produced using a homomixer. 250 g of ocher powder, 150 g of water glass (sodium silicate) type III manufactured by Sanwa Kogyo Co., Ltd., 7.5 g of fibers made by Deantech Scoria, water dispersible acrylic resin (emulsion acrylic resin) made by Ogon Bond Co., Ltd. ) 5 g of each was mixed, and CMC as a thickener was added so that the viscosity became about 100,000 cps, and a loess slurry containing silicate was produced. This is uniformly mixed with 50 ml of sulfuric acid aqueous solution diluted to 10% concentration at a very high speed, mixed, gelled within 8 seconds, solidified, heated in an oven at 100 ° C. for 2 hours, dried and foamed ceramic Manufactured.

Example 6
Add an amount corresponding to 4% of the weight of water to the animal foam produced by Korea Sangyo Co., Ltd., and use the bubble generator to produce a foaming aqueous solution. 200 g of powder is collected and mixed, 100 g of sodium silicate (sodium silicate) manufactured by Sanwa Industry Co., Ltd. is mixed, and CMC as a thickener is added so that the viscosity becomes about 200,000 cps. Thus, a blast furnace slag foaming slurry containing silicate was produced. 25 ml of glyoxal solution was added and mixed uniformly and allowed to stand for 15 minutes, then the blast furnace slag foam slurry was gelled and solidified, and heated and dried for 30 minutes using ultra-high frequency to produce a foam ceramic. .

Comparative Example 1
It was produced in the same manner as in Example 1 except that the step of forming a three-dimensional silica network with CO ₂ was omitted.

Comparative Example 2
It was produced in the same manner as in Example 2 except that the step of forming the three-dimensional silica network with CO ₂ was omitted.

Comparative Example 3
Prepared as in Example 2, except that the step of forming the three-dimensional silica network with sodium bicarbonate was omitted.

Comparative Example 4
It was produced in the same manner as in Example 4 except that the step of forming a three-dimensional silica network by immersing in an aqueous sulfuric acid solution diluted to 10% concentration for 15 seconds was omitted.

Comparative Example 5
It was produced in the same manner as Example 5 except that the step of forming a three-dimensional silica network by mixing 50 ml of an aqueous sulfuric acid solution diluted to 10% concentration was omitted.

Comparative Example 6
The product was prepared in the same manner as in Example 6 except that the step of forming a three-dimensional silica network by adding 25 ml of a 40% glyoxal solution was omitted.

Table 1 shows the results of experiments performed to compare the effects of the ceramic foams of Comparative Examples 1 to 6 and Examples 1 to 6 according to the present invention. In particular, in order to examine the durability of a three-dimensional silica network capable of maintaining water resistance, it was confirmed whether or not the foamed ceramic manufactured according to the example of the present invention floats in water for 30 days.

  As shown in Table 1, the foams produced in Comparative Examples 1 to 6 do not go through a gelation stage in which a three-dimensional silica network is formed even though the foamed aqueous solution contains a silicate inside the foamed aqueous solution. The foamed foam is defoamed and a lightweight foamed ceramic cannot be obtained. On the other hand, in the foamed ceramics manufactured according to Examples 1 to 6 according to the present invention, the ceramic slurry containing the silicate gels at the formation stage of the three-dimensional silica network, and the foamed fine bubbles are maintained and cured. Therefore, the density is low, and the heat insulation effect and the soundproofing effect due to the air layer (bubbles) contained in the foamed ceramic are excellent. Moreover, even if it contains an acrylic resin, which is a water-dispersible resin for improving water resistance as in Comparative Examples 4 to 5, the product immediately sinks when placed in water. If not, it can be seen that the foamed ceramic slurry is defoamed, and fine bubbles are hardly formed between the ceramic particles. In Examples 4 to 5, it was found that the acrylic resin contained in the three-dimensional silica network formed by gelation in the drying stage was coated on the ceramic surface and the water resistance increased rapidly, and the fiber was added. It has excellent durability.

  The present invention provides a foamed ceramic in which a large amount of fine bubbles are formed in various shapes, and a method for producing the same. The foamed ceramic manufactured according to the present invention has a high heat insulating effect and a soundproofing effect, and there is no fear that toxic gas is generated at the time of fire. Therefore, it is possible to prevent human lives from being damaged by toxic gas at the time of fire. In addition, the manufacturing process can be simplified, the production unit price can be lowered, and environmental pollution during manufacturing can be greatly reduced.

  In addition, since the foamed ceramic manufactured according to the present invention can reduce equipment costs without requiring high heat during the manufacturing process, the ceramic slurry in the manufacturing stage of the foamed ceramic maintains an appropriate level of viscosity and maintains a predetermined mold. The ceramic slurry is allowed to flow into and hardened to produce a foamed ceramic having a desired shape.

  In addition, since the foamed ceramic produced according to the present invention is foamed with a large amount of fine bubbles and has a low density, it can be reduced in weight and can be easily installed as a heat insulating material and a sound absorbing material.

  While the invention has been described with reference to the accompanying drawings and preferred embodiments, the invention is not limited thereto but is defined by the appended claims. It should be understood that those skilled in the art can make improvements and modifications without departing from the spirit and scope of the invention as defined in the appended claims.

Claims (29)

A ceramic slurry formed by mixing foam, silicate, ceramic powder, and additives in which fine bubbles are formed by a foam diluted with water;
A foamed ceramic comprising: a gelling agent that is supplied to the ceramic slurry and maintains a shape of the ceramic slurry to form a three-dimensional silica network.   The foamed ceramic according to claim 1, wherein the foaming agent is diluted at a weight ratio of 100: 0.1 to 10 with respect to water.   2. The foaming agent according to claim 1, wherein the foaming agent is selected from an amino acid-based animal foaming agent and a plant foaming agent containing an alkylbenzene sulfonate-based material, sodium lauryl sulfate, or an ester thereof as an active ingredient. The ceramic foam described.   2. The ceramic foam according to claim 1, wherein the silicate is included in a weight ratio of silicate to the ceramic powder of 100: 20 to 160. 3.   The foamed ceramic according to claim 1, wherein the ceramic slurry has a viscosity of 5,000 to 200,000 cps.   The silicate contained in the ceramic slurry is selected from one to four types of solution type sodium silicate, powder type sodium silicate, potassium silicate, lithium silicate, and sodium aluminum silicate. The foamed ceramic according to claim 1.   The ceramic powder contained in the ceramic slurry is barleystone, ocher stone, aragonite, high-grade clay, silicate mineral, magnesite, bauxite, bentonite, pumice, borate, serpentine, acid clay, iron oxide, stone meteorite , Carbonate mineral, attapulgite, sepiolite, soft jade, apatite, illite (mica), feldspar, pearlite, nepheline, zeolite, barite, talc, diatomite, graphite, hectorite, clay mineral, zirconium mineral, titanium mineral, The foamed ceramic according to claim 1, which is selected from tourmaline, fume silica, aerogel, fly ash, and blast furnace slag powder.   The foamed ceramic according to claim 7, wherein the ceramic powder has a particle size of 5 nm to 400 μm.   The foamed ceramic according to claim 1, wherein the additive mixed with the ceramic slurry includes natural fibers or artificial fibers.   The foamed ceramic according to claim 9, wherein the fiber has a thickness of 3 to 50 μm.   The foamed ceramic according to claim 9, wherein a length of the fiber is 1 to 50 mm.   The additive added to the ceramic slurry includes any one of a water dispersible polymer resin and a fine powder polymer resin for water resistance and reinforcement of the foamed ceramic. The foam ceramic described in 1.   The foamed ceramic according to claim 12, wherein the water-dispersible polymer resin is selected from acrylic, vinyl acetate, alkyd, melamine, and styrene butadiene rubber solutions.   The fine powder polymer resin is polyethylene terephthalate (PET), low density polyethylene, high density polyethylene, vinyl chloride resin (PVC), polymethyl methacrylate (PMMA), polystyrene (PS), polypropylene (PP), ethylene vinyl acetate. The foamed ceramic according to claim 12, wherein the foamed ceramic is selected from (EVA), polyurethane (PU), and polycaprolactone.   The foamed ceramic according to claim 1, wherein the gelling agent is selected from carbon dioxide gas, dry ice, bicarbonate, glyoxal, ethylene glycol diacetate, organic acid, and inorganic acid.   The foamed ceramic according to claim 15, wherein the gelling agent is introduced in a stoichiometric equivalent to silicate.   The foamed ceramic according to claim 15, wherein the bicarbonate is selected from sodium bicarbonate, potassium bicarbonate, and ammonium bicarbonate.   The foamed ceramic according to claim 15, wherein the organic acid or inorganic acid is selected from hydrochloric acid, nitric acid, sulfuric acid, phosphoric acid, hydrofluoric acid, formic acid, acetic acid, citric acid, maleic acid, and oleic acid. . A first stage of diluting the foam with water;
A second step of forming a large amount of fine bubbles using a foaming device for the foamed agent diluted with water;
A third stage in which the foam obtained in the second stage is mixed with silicate, ceramic powder and additives to form a ceramic slurry;
Adding a gelling agent to the ceramic slurry, and maintaining a shape of the ceramic slurry to form a three-dimensional silica network;
A method for producing a foamed ceramic, comprising: drying the ceramic slurry to remove moisture inside, and fusing the additive to increase water resistance.   The second step is characterized in that the foaming agent is rotated at a speed of 500 to 12,000 rpm in a foaming apparatus having rotating blades to disperse the foaming agent at a high speed to form a large amount of fine bubbles. 19. A method for producing a foamed ceramic according to item 19.   The method according to claim 19, wherein in the second step, fine bubbles are formed using a compressed gas in a foaming apparatus including a compressor.   The method according to claim 19, wherein the third step is to form a ceramic slurry by mixing foam, silicate, ceramic powder and additives in a foaming apparatus.   In the fourth step, a gelling agent selected from carbon dioxide gas, dry ice, bicarbonate, glyoxal, ethylene glycol diacetate, organic acid, and inorganic acid is mixed with the ceramic slurry to obtain a three-dimensional structure. The method for producing a ceramic foam according to claim 21, wherein a silica network is formed.   The method for producing a foamed ceramic according to claim 21, wherein the fifth stage is dried by a method selected from room temperature drying with air, hot air drying with an oven, and heat drying using an ultra high frequency wave. .   25. The method for producing a foamed ceramic according to claim 24, wherein the hot air drying by the oven or the heat drying using the ultra high frequency is performed at 80 to 250 ° C.   The method according to claim 21, wherein in the third step, the ceramic slurry is formed to have a viscosity of 5,000 to 200,000 cps.   The method for producing a foamed ceramic according to claim 21, wherein in the fourth step, a stoichiometric equivalent of a gelling agent with respect to silicate is introduced into the ceramic slurry. The additive is selected from water-dispersible resin or fine powder polymer resin for water resistance and reinforcement of the foamed ceramic;
The method for producing a foamed ceramic according to claim 21, wherein in the fifth step, the water-dispersible resin or the fine powder polymer resin as the additive is fused. A first stage of diluting the foam with water;
A second step of forming a large amount of fine bubbles using a foaming device containing a foaming agent diluted with water;
A third stage in which the foam obtained in the second stage is mixed with a silicate, ceramic powder, and a water-dispersible resin or fine powder polymer resin as an additive to form a ceramic slurry in the foaming apparatus. When,
A gelling agent selected from carbon dioxide gas, dry ice, bicarbonate, glyoxal, ethylene glycol diacetate, organic acid, and inorganic acid is supplied to the ceramic slurry in a stoichiometric equivalent to silicate. A fourth stage of maintaining the shape of the ceramic slurry to form a three-dimensional silica network;
And a fifth step of increasing the water resistance by fusing the water-dispersible resin or the fine-powder polymer resin to dry the ceramic slurry to remove internal moisture. Production method.

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