JP3492031B2 - Method for producing inorganic cured product - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing an inorganic cured product used for building materials and the like. 2. Description of the Related Art In the case of preparing an inorganic cured product, a curable material mainly composed of an aqueous solution of an alkali metal silicate and a curing agent is charged into a mold made of a synthetic resin or rubber material and cured. When the alkali metal silicate aqueous solution is contained in the conductive material, the “fit-in” between the mold surface and the curable material is poor, bubbles are easily generated between the two, and the appearance of the obtained cured product is reduced. There was a problem that it became worse. [0003] For this reason, for example, Japanese Patent Application Laid-Open No. 7-10634.
Japanese Patent Application Laid-Open Publication No. H11-157572 discloses a method of applying a silicone emulsion-based surfactant to the surface of a mold, thereby improving “fitting-in” between the curable material and the mold, and obtaining a cured body having a good appearance. It has been disclosed. However, in this method, it is necessary to apply a large amount of a silicone emulsion-based surfactant, and when the surfactant is subjected to post-processing such as painting on the surface of the cured product due to the surfactant remaining on the surface of the cured product, There was a problem that the adhesion of the coating film deteriorated. The present invention has been made in view of the above-mentioned drawbacks, and an object of the present invention is to provide a method for producing an inorganic cured product which has excellent surface finish and does not adversely affect post-processing. To provide. [0005] The process for producing an inorganic cured product according to the present invention comprises the steps of: preparing an SiO ₂ -Al ₂ O ₃ -based inorganic powder (a);
100 parts by weight, alkali metal silicate (b) 0.2 to 45
When a curable material composed of 0 parts by weight and 35 to 1,500 parts by weight of water (c) is injected into a molding die whose surface is made of a synthetic resin or rubber material and cured, the surface of the die is hardened. In advance, a surfactant (silicone emulsion system
An aqueous solution (excluding an emulsion) of a surfactant (excluding a surfactant) is applied. The SiO ₂ -Al ₂ O ₃ used in the present invention
As the inorganic powder (a), the ratio of SiO ₂ is 25 to
Those having a ratio of 85% by weight and Al ₂ O ₃ of 90 to 10% by weight are preferably used. As such a powder,
Fly ash, metakaolin, kaolin, mullite,
Corundum, dust when producing alumina-based abrasives,
Examples include pulverized and fired bauxite, but are not limited thereto as long as the composition and particle size are appropriate. The powder may be used as it is, but for activation,
Thermal spraying, pulverization classification, and mechanical energy may be applied. As a method of the thermal spraying, a thermal spraying technique applied to a ceramic coating can be used.
As the thermal spraying technology, material powder is 2,000 to 16,
It is melted at a temperature of 000 ° C. and sprayed at a speed of 30 to 800 m / sec, and includes a plasma spraying method, a high energy gas spraying method, an arc spraying method and the like. The specific surface area of the obtained powder is preferably from 0.1 to 100 m ² / g. Conventionally known methods are employed for classifying and pulverizing the above powder, including classification by sieve, specific gravity, wet sedimentation, and the like; pulverization by a jet mill, roll mill, ball mill, and the like. These methods are used in combination. May be done. As a method of applying the mechanical energy, a ball medium mill,
A medium stirring type mill, a roll mill, or the like can be used. The mechanical energy to be applied is in a range of 0.5 to 30 kWh / kg, since the smaller the energy, the more difficult it is to activate the powder; Is preferred. [0009] The fly ash, if necessary,
A firing treatment may be performed. The firing temperature is preferably from 400 to 1,000 ° C., because when the firing temperature is low, the black color of the fly ash remains and coloring becomes difficult, and when the firing temperature is high, the reactivity with the alkali metal silicate (b) decreases. The alkali metal silicate (b) used in the present invention is M ₂ O · nSiO ₂ (where M is K, N
a or a metal selected from Li), and when the value of n is small, a dense foam cannot be obtained, and when the value of n is large, the viscosity of the aqueous solution increases and mixing is difficult. Therefore, it is preferably from 0.05 to 8, more preferably from 0.5 to 2.5. The alkali metal silicate (b) is preferably added in the form of an aqueous solution. The lower the concentration of the aqueous solution, the lower the reactivity with the fly ash powder, and the higher the concentration, the more likely it is to produce solids. 10-60
% By weight is preferred. In the aqueous solution of the alkali metal silicate (b), the alkali metal silicate (b) may be dissolved in water as it is under pressure and heating. pressure as the SiO ₂ component n becomes a predetermined amount equal, it may be dissolved under heating. In the curable material used in the present invention,
When the amount of the alkali metal silicate (b) is small, the curing does not proceed sufficiently, and when the amount is large, the water resistance of the obtained inorganic cured product is reduced. It is limited to 0.2 to 450 parts by weight, preferably 10 to 350 parts by weight, and more preferably 20 to 350 parts by weight.
250 parts by weight. The water (c) used in the present invention may be added alone or as an aqueous solution of the alkali metal silicate (b). In the curable material, if the amount of the water (c) is too small, mixing becomes difficult and curing does not proceed sufficiently. If the amount of the water (c) is too large, the strength of the obtained inorganic cured product decreases. a) It is limited to 35 to 1,500 parts by weight, preferably 45 to 1,000 parts by weight, and more preferably 50 to 500 parts by weight based on 100 parts by weight. A foaming agent may be added to the curable material, if necessary, to obtain a foamed cured product. Examples of the foaming agent include peroxides such as hydrogen peroxide, sodium peroxide, potassium peroxide, and sodium perborate; Mg, Ca, Cr,
Mn, Fe, Co, Ni, Cu, Zn, Al, Ga, S
Metal powders such as n, Si, and ferrosilicon are exemplified. In the above-mentioned curable material, the amount of the foaming agent is
If the amount is too small, the expansion ratio becomes too small to obtain a foamed cured product, and if the amount is too large, the foaming gas becomes excessive and foam breakage occurs. Therefore, 0.01 to 10 parts by weight with respect to 100 parts by weight of the inorganic powder (a). Parts are preferred. When hydrogen peroxide is used as the foaming agent, it is preferable to use an aqueous solution in consideration of safety and stable foaming. When metal powder is used, the particle size is 200 μm or less in order to obtain stable foaming. It is preferred that A foaming aid may be added to the curable material as needed. The foaming assistant is not particularly limited as long as it causes foaming uniformly. Examples thereof include fatty acid metal salts such as zinc stearate, calcium stearate, and zinc palmitate; silica gel, zeolite, activated carbon, and alumina powder. Porous powders and the like may be mentioned, and these may be used alone or in combination of two or more. If necessary, an inorganic filler may be added to the curable material. The inorganic filler is not particularly limited as long as it does not dissolve in water, does not inhibit the curing reaction in the present invention, and does not react with the alkali metal silicate (b). For example, silica sand, river sand, Zircon sand, crystalline alumina, rock powder, volcanic ash, silica flour, silica fume, bentonite, blast furnace slag, etc .; mixed materials for cement; natural minerals such as sepiolite, wollastonite, mica, calcium carbonate, diatomaceous earth, etc. And these may be used alone,
Two or more kinds may be used in combination. The average particle size of the above-mentioned inorganic filler is preferably 0.01 to 1,000 μm because the viscosity of the above-mentioned curable material increases when the average particle size is small and the foamability becomes unstable when the average particle size is large. In the above-mentioned curable material, the amount of the inorganic filler is preferably 700 parts by weight or less with respect to 100 parts by weight of the inorganic powder (a) since the strength of the obtained foam decreases as the amount increases. Reinforcing fibers may be added to the curable material as required. As the reinforcing fiber, any one can be used according to the required performance of the cured body. For example, vinylon fiber, polyamide fiber, polyester fiber, polypropylene fiber, carbon fiber, aramid fiber, glass fiber, potassium titanate fiber , Steel fibers and the like. When the fiber diameter of the reinforcing fiber becomes thinner, it reaggregates in the mixing step and fiber balls are easily formed by entanglement. Therefore, even if the amount of the reinforcing fiber is increased, the strength of the obtained cured product does not improve. The thickness is preferably 1 to 500 μm because the reinforcing effect for improving the strength is reduced. Further, the fiber length of the reinforcing fibers is preferably 1 to 15 mm, because the shorter the fiber length, the smaller the reinforcing effect of strength improvement, and the longer the fiber length, the lower the fiber dispersibility and orientation. In the curable material, the amount of the reinforcing fiber is preferably 10 parts by weight or less with respect to 100 parts by weight of the inorganic powder (a) since the dispersibility decreases as the amount increases. In order to further reduce the weight of the curable material, inorganic foams such as silica balloons, perlites, fly ash balloons, shirasu balloons, glass balloons, foamed clays, etc .; phenolic resins, urethane resins, polyethylene resins A balloon made of synthetic resin such as vinylidene chloride or acrylic resin may be added. These may be used alone or in combination of two or more. The curable material may further contain, if necessary, alumina cement, γ-alumina, sprayed alumina, alkali metal aluminate, aluminum hydroxide and the like. The material of the mold used in the present invention includes rubber materials such as urethane rubber, silicone rubber, fluorine rubber, natural rubber and styrene-butadiene rubber; FRP materials such as polyester and epoxy resin; Polymer, acrylic resin, vinyl chloride resin, polyethylene,
In addition to simple substances such as synthetic resin-based materials such as polypropylene, polystyrene, and fluororesin, those obtained by coating the surface of iron, aluminum, or the like with the above materials are preferably used. The above-mentioned materials are processed into a mold used in a conventionally known molding method such as casting and extrusion. In the production method of the present invention, an aqueous solution of a surfactant is applied to the surface of the mold in advance. Any surfactant can be used as long as it is water-soluble. From the viewpoint of hydrophilicity, HLB (Hydrophile-Lip) can be used.
It is preferable that the material has an oval balance value of about 8 to 15. In terms of alkali resistance, if the effect of preventing repelling is exerted at the moment when the curable material is poured, the appearance is improved and there is no particular problem. . The hydrophobic group of the above-mentioned surfactant includes
It is preferable that the surface material of the mold is familiar with the material of the mold. If the mold is made of epoxy resin or urethane rubber, a hydrocarbon-based surfactant can be used, and a mold in which a fluorine-based resin is applied to the surface is used. In this case, a hydrocarbon-based surfactant has a sufficient effect, but a fluorine-based surfactant further improves the effect. Examples of the surfactant include polyhydric alcohol ester EO adducts such as sorbitan laurate monoester EO (ethylene oxide) adduct, polyethylene glycol laurate monoester, polyethylene glycol laurate diester and other polyethylene glycol esters. Nonionic surfactants such as higher alcohol EO adducts such as lauryl alcohol EO adducts and alkylphenol EO adducts of nonylphenol EO adducts; aerosol OT type; alkylbenzene sulfonates such as sodium dodecylbenzenesulfonate; sodium lauryl sulfate And anionic surfactants such as sodium alkylnaphthalenesulfonate, sodium alkyldiphenylethersulfonate, and butyl oleate. It is. In addition to the above, when the surface of the mold is a fluororesin, a fluorosurfactant such as a perfluoroalkyl EO adduct, a perfluoroalkyl carboxylate, a perfluoroalkyl phosphate, or a perfluoroalkyl betaine is used. Agents can be used. The concentration of the aqueous solution of the surfactant is preferably 0.05 to 50% by weight, more preferably 0.1 to 50% by weight. -20% by weight. When the amount of the aqueous solution of the surfactant is too small, sufficient curing cannot be obtained, and when the amount is large, the curing reaction of the cured product is adversely affected. Therefore, the amount is preferably 10 to 1,000 g / m ² . Further, a thickener may be added to the aqueous solution of the surfactant to improve the adhesion to the mold.
Examples of the thickener include water-soluble polymers such as methylcellulose, carboxymethylcellulose, polyvinyl alcohol, and polyacrylamide; polysaccharides such as xanthan gum and glucan; and inorganic thickeners such as sepiolite and antigolite. The above-mentioned thickener is an organic type and is 0.01
It is preferable to add so as to have a concentration of １1% by weight and an inorganic one having a concentration of 0.1 to 10% by weight. The surfactant aqueous solution can be applied using a brush, a roller, a spray, or the like. In order to obtain an inorganic cured product by the production method of the present invention, first, the above alkali metal silicate (b) is pressurized,
It is dissolved in at least a part of water (c) under heating, and the above-mentioned inorganic powder (a) and, if necessary, the remaining water (c), reinforcing fiber, inorganic filler and the like are mixed to form a paste-like curable material. After the preparation, a method in which the curable material is formed into a predetermined shape by a conventionally known molding method such as casting or extrusion molding and cured is used. When a foaming agent is mixed into the curable material, the alkali metal silicate (b) is added to an aqueous solution of at least a portion of water (c) under pressure and heat. The foaming agent may be added and mixed at the same time, but since the reaction speed of the foaming agent is generally high, it is preferable to mix the foaming agent with the pasty curable material in which materials other than the foaming agent are previously mixed. The curing of the curable material may be carried out at room temperature, but for example, by heating at 50 to 110 ° C. for 30 minutes to 8 hours to accelerate the curing reaction, mechanical properties can be improved. . In general, synthetic resins and rubber materials have hydrophobic properties,
When this comes into contact with the aqueous slurry, "repelling" occurs. The aqueous solution of the alkali metal silicate used in the present invention has a higher surface tension than that of water.
5. The surface tension of the aqueous sodium silicate solution having a solid content of 36.7% by weight is 80.2 dyn / cm, and 72.0 dyn of water.
/ Cm. Therefore, repelling tends to occur as compared with a cement-based material widely used as an inorganic material. In the present invention, in order to prevent this repelling, when an aqueous solution of a surfactant is applied to the hydrophobic groups present on the surface of the resin mold , the hydrophobic groups of the surfactant are arranged on the resin side and the hydrophilic groups are arranged on the surface side. It is believed that the arrangement prevents repelling between the curable material and the mold surface. At this time, such an arrangement does not occur unless water is present, and in the case of a cement-based material, the above-described arrangement is caused by the water in the curable material using an aqueous solution of a surfactant. Although it is possible, the effect can not be obtained in a short time because the viscosity of the slurry of the present curable material is high. BEST MODE FOR CARRYING OUT THE INVENTION [Preparation of Inorganic Powder] Inorganic Powder (1) Fly ash (manufactured by Kanto Kako Co., Ltd., average grain size 20 μm: J
(Measured in accordance with IS A6201) was classified by a classifier (“Model: TC-15” manufactured by Nisshin Engineering Co., Ltd.) to obtain an inorganic powder having a particle size of 10 μm or less. Inorganic powder (2) Kaolin (composition: 45.7% by weight of SiO ₂ , Al ₂ O ₃
38.3% by weight, average particle size: 8 μm, BET specific surface area: 5.8 m ² / g) A raw material powder was sprayed at a combustion temperature of 2,500 ° C. and a spray particle speed of 50 m / sec to obtain an active inorganic powder (composition: 49.7% by weight of SiO _2, 47.0% by weight of Al ₂ O ₃ , average particle diameter: 49 μm, BET specific surface area: 64.3 m ²
/ G). Inorganic powder (3) Fly ash (manufactured by Kanto Kako Co., Ltd., average grain size 20 μm, B
ET specific surface area 1.8 m ² / g: measured according to JIS A6201) 100 parts by weight and a mixed solution of triethanolamine 25% by weight and ethanol 75% by weight.
5 parts by weight of Ultra Fine Mill (Mitsubishi Heavy Industries "A"
T-20 ", using zirconia balls of 10 mmφ, ball filling rate of 85% by volume), and applying mechanical energy of 25 kwh / kg to obtain fly ash powder. Inorganic Powder (4) Metakaolin (“SATINTON” manufactured by Engelhard Co., Ltd.)
ESP33 ", an average particle size of 3.3 μm, and a BET specific surface area of 13.9 m ² / g). [Types of Surfactant] Surfactant (1) Nonylphenol EO (ethylene oxide) 10 mol adduct (“Nonipol 100” manufactured by Sanyo Chemical Industries, Ltd.). Surfactant (2) Sodium alkyl diphenyl ether disulfonate (“Sandet BL” manufactured by Sanyo Chemical Industries, Ltd.). Surfactant (3) Perfluoroalkyl phosphate ("Surflon S-112" manufactured by Asahi Glass Co., Ltd.). Surfactant (4) Silicone emulsion surfactant (“SN Deformer 381” manufactured by San Nopco) [Types of Mold] Mold (1) Urethane rubber pattern (“Mold Star” manufactured by Tokai Rubber Industries, Ltd.) MP-02 "). Mold (2) Silicone rubber mold (manufactured by Shinei Kogyo). The pattern on the mold surface was transferred based on the mold (1). Mold (3) An aluminum die-cast product with a fluororesin powder coated on the surface. The pattern on the mold surface was transferred based on the mold (1). Mold (4) A die-cast aluminum product coated with epoxy resin on the surface. The pattern on the mold surface was transferred based on the mold (1). Examples 1 to 17 and Comparative Examples 1 to 6 A predetermined amount of alkali metal silicate [M ₂ O shown in Tables 1 to 4
/ NSiO ₂ , n = 1.5, M = Na, K (molar ratio 1:
1)] in an autoclave at 130 ° C., 7 kg /
Dissolved in water in a predetermined amount shown in Tables 1 to 4 in cm ² ,
4, a predetermined amount of wollastonite ("Chemolit A-60" manufactured by Tsuchiya Kaolin), inorganic powder and calcium stearate were mixed with an omni mixer (manufactured by Chiyoda Giken Kogyo Co., Ltd.) to obtain a uniform paste. did. Separately, an aqueous solution of a surfactant is diluted in advance to a predetermined concentration shown in Tables 1 to 4 [in Example 4, methylcellulose ("Metroze 90SH-5000" manufactured by Shin-Etsu Chemical Co., Ltd.) was used as a thickener.
At the same time) to obtain a uniform aqueous solution. This aqueous solution was applied to the surface of the mold by spraying a predetermined amount shown in Tables 1-4. Further, when a non-foamed cured product is obtained from the paste, the paste is applied with an aqueous solution of a surfactant using the materials shown in Tables 1 to 4 and poured into a molding die. It was placed in an oven at 85 ° C. and heated for 6 hours to obtain an inorganic cured product of 30 × 30 × 2 (cm).
When a foamed cured product is obtained from the above paste, a predetermined amount of aluminum powder ("350F" manufactured by Minarco, particle size 7) shown in Tables 1 to 4 is added to the paste.
0 μm or less) or aqueous hydrogen peroxide (concentration 10% by weight,
35% by weight of the reagent) was added thereto, and the mixture was stirred for 30 seconds, poured into a mold to which an aqueous solution of a surfactant shown in Tables 1 to 4 was applied, and then placed in an oven at 85 ° C together with the mold. The mixture was heated for 6 hours to obtain a foamed inorganic cured product of 288 × 92 × 10 (cm). The particle size was measured using a laser diffractometer (Model: PRO700S, manufactured by Seishin Co., Ltd.) The following inorganic cured products obtained in the above Examples and Comparative Examples were used. Evaluation was performed, and the results were shown in Tables 1-4.
It was shown to. (1) Appearance evaluation The number of air bubbles having a diameter of 2 mm or more was counted over the entire surface of the inorganic cured product obtained above by visual observation, and 30 cm
It was represented by the number of bubbles per corner. (2) Evaluation of coating film adhesion After the inorganic cured product obtained above was preheated to 60 ° C. with a hot air drier, an acrylic resin emulsion paint (“Glagen MX-” manufactured by Dainippon Paint Co., Ltd.) was used. EX ”) with a coating amount of 350 g / m
² and apply 100 hot air dryer.
Dry at 20 ° C. for 20 minutes. Regarding this painted surface, JIS
A grid test was performed in accordance with K5400 to evaluate the initial adhesion. The evaluation was expressed by the number of remaining pieces in 25 grids after a peeling test using a cellophane tape. [Table 1] [Table 2] [Table 3] [Table 4] The method for producing an inorganic cured product according to the present invention has the above-described structure. By applying an aqueous solution of a surfactant to the surface of a mold in advance, the surface finish is beautiful. And other inorganic hardened materials which do not adversely affect post-processing.

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Claims (1)

(57) [Claims 1] _{(a) SiO 2 -Al 2 O} 3 based inorganic powder 100 parts by weight, (b) an alkali metal silicate 0.2 to 45
In a method for producing an inorganic cured product, a curable material comprising 0 parts by weight and (c) 35 to 1,500 parts by weight of water is poured into a molding die having a surface formed of a synthetic resin or a rubber material and cured. , A surfactant is added to the surface of the mold in advance.
Water-soluble (excluding silicone emulsion surfactants)
A method for producing an inorganic cured product, which comprises applying a liquid (excluding an emulsion) .