JPS6149273B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a new method for producing an inorganic heat insulating material,
In detail, foaming and curing occur simply by mixing the raw materials into a paste form, and the foaming and curing occurs within a short period of time without the need for any heating operation.It has excellent heat insulation properties, mechanical strength, water resistance, moisture resistance, and weather resistance. The present invention relates to a novel and useful method for stably obtaining an excellent inorganic heat material partially composited with an organic substance. Various inorganic heat insulating materials have been proposed so far. For example, any aqueous alkali metal silicate solution necessarily requires heating (usually at 200 to 900°C), and is inherently inferior in water resistance and moisture resistance, making it easily susceptible to contact with moisture. There are drawbacks such as the elution of alkali metals, which significantly reduces the mechanical strength of the foamed heat insulating material, and it has almost no practical use as a heat insulating material. Inorganic lightweight materials such as lightweight concrete and lightweight mortar that use Portland cement as a binding material are also known, but they have a large specific gravity (1.0
Front and back) Lacks practicality as a heat insulating material. Furthermore, lightweight aerated concrete cured in an autoclave is complicated to operate, and lightweight foams are difficult to obtain, with the bulk specific gravity of even the lightest concrete reaching 0.5 or more. The present invention provides a useful inorganic heat insulating composition of an organic material composite type that has significantly improved performance over conventional inorganic lightweight heat insulating materials, particularly in terms of light weight, mechanical strength, chemical resistance, and durability. It is. That is, the present invention essentially comprises (A) a water-soluble alkali metal silicate, (B) a cement substance, (C) a metal foaming agent, (D) a foaming stabilizer, and (E) a by-product produced by electric heating or gold. Silica dust and synthetic resin or synthetic rubber powder,
The present invention relates to a method for producing an inorganic heat insulating material composition characterized by comprising granules or an aqueous dispersion. The method for manufacturing the inorganic heat insulating material of the present invention is such that it can easily be made into a foamed heat insulating material at room temperature and pressure by simply mixing the above six components and making it into a paste.The curing time is short and it can be molded into complex shapes depending on the weather conditions. It has a uniform bulk specific gravity regardless of the The heat insulating material after foam hardening can be adjusted to an extremely low bulk density of 0.1 to 0.3 g/ ^cm3 , which is impossible with lightweight aerated concrete, which is known to have excellent mechanical strength, and has excellent thermal conductivity. The ratio is also about 1/1 that of lightweight aerated concrete.
Not only can it be reduced by 3 to 1/2, but it also has a uniform cell structure, and the cell structure is dense and extremely strong. Therefore, the heat insulating material of the present invention has excellent heat insulating properties, mechanical strength, water resistance, moisture resistance, and weather resistance, and is therefore of great value. Particularly notable effects include improvements in mechanical strength and weather resistance. In other words, without blending the silica dust produced by electric heating and gold as component (E) with synthetic resin or synthetic rubber, the free alkali in the foamed insulation material will gradually degrade to the surface of the foamed material as it moves within the solid phase. Otherwise, it was not possible to sufficiently prevent the phenomenon of white powder separating inside the material, and this phenomenon not only damaged the aesthetic appearance of the insulation material but also reduced the mechanical strength. As a result of intensive research focused on preventing this, the above-mentioned invention was completed. According to the inventors' estimation, unique silica dust produced by electric heating and gold, and powder, granules, or water dispersion of synthetic resin or synthetic rubber are uniformly dispersed in the foam insulation material. It is believed that the free alkali content is apparently fixed, especially with the aid of the heat generated during the foam curing process, and becomes even stronger after drying. At the same time, heat insulating materials containing fixed dilute alkali content show very good results in weather resistance tests that include various environmental conditions such as rainfall, ultraviolet irradiation, and changes in temperature and temperature. In the present invention, it is essential to use a water-soluble alkali metal silicate as component (A), and constituents thereof include, for example, water-soluble silicates of alkali metals such as lithium, sodium, and potassium; As long as component (A) is water soluble,
Although there are no restrictions on the composition or molar ratio, it is preferable that the molar ratio of sio ₂ to the alkali metal is about 1.5 to 4.0. The above component (A) may be used alone or in combination.
It can be advantageously used in the form of a powder or an aqueous solution by using a combination of two or more species, but the solid content concentration should be about 10 to 60% by weight when prepared into a paste, and if used in an aqueous solution, Set the solid content concentration in advance.
It is preferably in the form of an aqueous alkali metal silicate solution of 20% or more, usually about 20 to 60%. Below simply (A)
It is called an ingredient. Next, the cement substance used as component (B) includes what is commonly called cement in the chemical industry, and includes air-hardening cement, hydraulic cement, and special cement. Examples of air-hardening cements include lime such as quicklime, slaked lime, magnesia lime, and dolomite plaster; simple cements such as calcined gypsum, Keens cement, Parian cement, and martin cement; and magnesia cement. Hydraulic cements include single cements such as hydraulic lime, natural cement, Portland cement, alumina cement, lime mixed cement, blast furnace cement, silica cement, fly ash cement, masonry cement, high sulfate cement, etc. An example of this is mixed cement. Furthermore, examples of the special cement include fire-resistant cement and acid-resistant cement. Of these, hydraulic cement is particularly desirable, but it is also effective not only to use the above-mentioned cement substances alone, but also to use a combination of hydraulic cement and air-hard cement, or to use the same Even with hard cement, two or more types can be sufficiently mixed. Hereinafter, it will simply be referred to as component (B). In the present invention, various metal elements, metal alloys, and intermetallic compounds can be used as the metallic foaming agent as component (C). Periodic table for metal elements
1B, 2A, 2B, 3A, 3B, 4A, 4B, 5A, 5B,
Any of those belonging to Groups 6B, 7B and 8 can be used, and among them, those belonging to the 3rd to 5th period are preferred.
Note that semimetallic elements such as boron and silicon can also be used in the present invention. In the present invention, alloys or metal compounds of the above metals (chemical combinations between metals or between metals and non-metals) can also be used in the same manner as the above metals. Representative examples of the alloy or intermetallic compound include Al-Si, Al-Ti, Al-Mn, Al-Cu,
Zn-S, Zn-Sn, Sn-Fe, Cu-Sn, Cu-Si,
Cu-Pb, Cu-NiFe-Ni, Fe-Mn, Fe-Cr,
Fe-Si, Mn-P, Mn-Ag, Si-Ni, Co-Sb, etc. are listed. The above (C) component is usually one or two of them.
It is better to use seeds or more in the form of fine powder, especially
It is preferable to use a particle size of 150μ or less. Hereinafter, it will simply be referred to as component (C). Further, in the present invention, the foaming stabilizer used as component (D) includes silica gel, zeolite, artificial zeolite, carbon black, activated carbon, and talc.
and mica (mica), and organic substances such as animal proteins and dimethyl silicon derivatives, which are conventionally known as foaming agents for cement systems, can be used. These (D) components have the effect of uniformly dispersing the (C) component in the system and stabilizing the foaming reaction.
Effective in generating fine, uniform bubbles. When the component (D) is an inorganic substance, it is usually preferably used in the form of a powder with a particle size of 200 μm or less. Hereinafter, it will simply be referred to as component (D). Furthermore, in the present invention, the silica dust produced by electric heating or gold as component (E) refers to the following. In electric heating and metallurgical methods, high temperatures of 2,000 to 3,000°C or higher are usually generated to heat-treat silica stone, a single metal element, or its raw ore, and in order to avoid an oxidizing atmosphere, coke or hydrogen gas with high reducing performance is used. It allows carbon monoxide, etc. to pass through, and when it is used with any metal or gold, oxides such as silica (Sio ₂ ) and alumina (Al ₂ O ₃ ) in the raw metal ore, which is the crude raw material, are removed. Most of it becomes vapor and decomposes into highly reactive metal elements, but
The vapor that combines with oxygen in the air or remains as silica or alumina is rapidly cooled in the air and becomes powdery. In this case, impurities such as sulfur, phosphorus, and carbon contained in the raw ore are often included, but the amount is relatively small and the fine powder that is produced as a by-product has a high silica content. Especially in the case of manufacturing silicon alloys, the purity of the silica component is extremely high, and these are collectively called silica dust. Among these, the silica dust used in the present invention is preferably one with a particle diameter of about 0.1 to 1.0 μ, a specific surface area of about 10 to 50 m ² /g, and a bulk specific gravity of about 0.1 to 0.3, and has a purity of about 80% silica by weight. % or more can be exemplified. Hereinafter, it will simply be referred to as component (E). Finally, the synthetic resin or synthetic rubber to be blended in the present invention is not particularly limited in type, and includes vinyl acetate, acrylic ester, ethylene, methyl methacrylate, vinyl chloride, styrene, vinyl propionate, epoxy, melamine, and urethane. , butadiene, chloroprene, isoprene, SBR,
NBR, vinylidene chloride, diallyl phthalate,
It can be used in the form of powder, granules, or aqueous dispersion of a homopolymer or a copolymer of two or more of diallyl maleate, dibutyl maleate, polyester, propylene, etc. Among these, thermoplastic materials are preferred, and in the case of aqueous dispersions, powders, and granules, those having a particle size of 2 mm or less are exemplified. below,
These are simply referred to as component (F). The blending ratio of the above components (A) to (F) may vary depending on the concentration, bulk specific gravity, and strength conditions of the desired product, especially when component (A) is used in the form of an aqueous solution. , usually the following can be done. That is, based on the solid content of component (A),
Approximately 10 to 100 of component (B) as a solid content per 100 parts by weight
Parts by Weight Preferably about 15 to 90 parts by weight, component (C) about 2 to 30 parts by weight, component (D) about 5 to 50 parts by weight if it is an inorganic substance, and about 5 to 50 parts by weight if it is an organic substance. The solid content is approximately 0.1 to 3 parts by weight, and the component (E) is approximately 5 to 3 parts by weight.
The solid content of component (F) is about 3 to 50 parts by weight. In general, if component (A) is present in excess, the bubbles and bulk specific gravity will not be stable, resulting in non-uniform foaming and poor water resistance.If component (B) is present in excess, the viscosity of the paste will increase when preparing the paste. Too much, and workability deteriorates. Furthermore, if the amount of component (C) is too low, foaming will be poor and the bulk specific gravity of the product will be heavy, whereas if it is too high, the air bubbles in the product will become large, resulting in excessive foaming, making it difficult to obtain the desired strength. When component (D) is an inorganic substance, too little will result in non-uniform foaming, while too much will make paste preparation difficult. When component (D) is an organic substance, if it is too large, open air bubbles will increase, leading to a decrease in insulation properties, and if it is too small, the stability effect cannot be maintained. If the amount of component (E) is too large, the shrinkage will be large during foam formation, which may cause clutching, while if it is too small, the insulation, weather resistance, and mechanical strength will be reduced. If the amount of component (F) is small, it will not be possible to improve not only water resistance and moisture resistance, but also weather resistance, which is specially mentioned in the present invention. It is difficult to knead and causes trouble during work. The inorganic heat insulating material of the present invention prepared in this way can be further mixed with lightweight aggregates, such as foamed silica, pearlite, vermiculite, etc., which are usually fired at temperatures of 1000°C or higher, as needed, thereby reducing the bulk specific gravity of the product. Can be adjusted. Furthermore, various known fillers such as gypsum, fused silica, calcined cristobalite, silicon carbide, boron nitride, silica stone, alumina, and glass fiber may be added for the purpose of increasing the volume or reinforcing the material. It is necessary to be careful about the amount added so as not to interfere with the reaction form of the essential components (A) to (F). This type of formulation usually has uniform air bubbles in the range of 0.5 to 10 mm, low specific gravity, high strength, low water content, water resistance, moisture resistance, chemical resistance, heat insulation, heat resistance, and weather resistance. An inorganic foam heat insulating material with excellent properties can be obtained. Embodiments of the present invention will be described in detail below. Example 1 An inorganic heat insulating material having the following composition was prepared. (A) Sodium silicate aqueous solution (sio ₂ /Na ₂ o molar ratio 2.0,
Concentration 20%) 100 parts by weight (B) Alumina cement (Al ₂ O ₃ / Cao molar ratio 0.7)
100 parts by weight (C) Metallic silicon 5 parts by weight (D) Activated carbon (5-50μ) 8 parts by weight (E) Silica dust by-produced during ferrosilicon production (SIO ₂ content 95 wt) 9 parts by weight (F) Ethylene vinyl acetate resin powder 5 parts by weight The above mixture was thoroughly stirred and foamed in a plastic container at room temperature and pressure to obtain a foamed heat insulating material. The physical properties of this product were a bulk specific gravity of 0.33 and a compressive strength of 11.5 Kg/cm ² . The temperature is 50℃ and the humidity is 80±20RH%.
When the foam was allowed to stand for 72 hours in a high humidity atmosphere filled with carbon dioxide gas, no powdering was observed on the surface or inside of the foam. Further, when the appearance of this product was observed after 250 hours in a sunshine-type accelerated weathering tester, no powdering was observed on the surface or inside. Examples 2 to 7 Based on the method of Example 1, the blending ratios shown in Table 1 were determined to obtain foamed heat insulating materials. The following tests were conducted on these foam insulation materials, and the results shown in Table 2 were obtained. The moisture resistance, weather resistance, and weather resistance tests were conducted in accordance with Example 1, and the other tests were conducted in the following manner. 1 Bulk specific gravity: According to JlS A1161. 2 Compressive strength: According to JIS A1161. 3 Water resistance: After immersing in water (20℃) for 24 hours, leave it in the air for 24 hours and check the state of powdering. 4 Alkali resistance: After immersing in a saturated Ca(OH) ₂ solution for 24 hours, leave it in the air for 24 hours and observe the state of powdering. 5 Compressive strength after water resistance test: JIS after water resistance test
According to A1161.

【table】

[Table] Comparative Example In Example 1, a test was conducted without mixing component (E) and component (F), and the results were as shown in Table 2.

【table】

【table】

Claims (1)

[Scope of Claims] 1 (A) water-soluble alkali metal silicate, (B) cement material, (C) metal foaming agent, (D) foaming stabilizer, and (E) by-produced by electric heating or gold. When mixing silica dust into a paste form in the presence of water to obtain an inorganic heat insulating material, synthetic resin or synthetic rubber powder, granules, or water dispersion is added and mixed. A method for producing superior inorganic insulation materials. 2 Water-soluble alkali metal silicate _sio2 / _Re2O
2. The method according to claim 1, wherein the molar ratio of R (wherein R represents an alkali metal) is from 1.5 to 4.0. 3. The method of claim 1, wherein the mixture to be mixed into a paste contains an amount of water such that the water-soluble alkali metal silicate is in the form of an aqueous solution having a concentration of about 10 to 60% by weight. 4 Silica dust produced by electric heating or gold has a particle size of approximately 0.1 to 1.0 μ, a specific surface area of approximately 10 to 50 m ² /g, a bulk specific gravity of approximately 0.1 to 0.3, and a purity of approximately 80% by weight or more of silica. The method according to claim 1, characterized in that: 5 The synthetic resin or synthetic rubber powder, granules, or water dispersion has thermoplasticity and has a particle size of approximately 2 mm.
(diameter) or less. 6 Relative to 100 parts by weight of water-soluble alkali metal silicate, approximately 10 to 100 parts of cement material is added, all as a solid content ratio.
parts by weight, about 2 to 30 parts by weight of a metallic foaming agent, about 0.1 to 50 parts by weight of a foaming stabilizer, about 5 to 70 parts by weight of silica dust produced by electric heating or gold, and about 3 parts by weight of synthetic resin or synthetic rubber. The method according to claim 1, characterized in that ~50 parts by weight are used.