JP5158733B2 - Method for obtaining a refractory molded article and a refractory molded article - Google Patents

Description

The present invention relates to a method for obtaining a refractory molded article using a composition that maintains alkali metal reducing ability and catalytic ability at room temperature and normal pressure, and a refractory molded article obtained thereby.
The composition can be mixed with any substance as a strong reducing agent, and is safe as a transport means for alkali metals having strong reactivity at room temperature.
The above composition has alkali metal reactivity and ceramic characteristics, such as corrosion resistance, heat resistance, and insulation, and further forms a composite by bonding with an organic polymer material. It is possible to improve the heat resistance. Moreover, the said composition can contribute to industry as a base material which mixes with all substances and adds new functions, such as heat resistance, to a substance. Furthermore, the composition is reduced to silica at a high temperature range of 800 ° C. or higher to produce an alkali oxide to be in a molten state. Using the produced alkali oxide as a curing agent, it is transferred to a tridymite crystal, oxidation resistance, A composition having excellent corrosion resistance is obtained.
The molten composition obtained at a high temperature can form a strong film excellent in oxidation resistance and corrosion resistance on all substances, and can prevent corrosion due to exhaust gas .

  The alloys of alkali metals and alkaline earth metals of Group I of the Periodic Table show very high reactivity in the metal state and neutral state, and spontaneously ignite when exposed to air and moisture. For this reason, it is stored in a vacuum or in an inert liquid. For example, metallic sodium is stored in kerosene or the like, and impurities must be removed during use. This is a significant limiting factor for the use and transportation of the metal.

  The composition of Na as a carrier is described in Patent Document 1 (Japanese Patent Publication No. 2007-520407) as “Method of impregnating silica gel with liquid alkali metal at normal temperature or high temperature in an inert atmosphere or under vacuum”. However, since the manufacturing process uses metallic sodium as a raw material, the handling is not changed, and an inert gas and a heating process in vacuum are involved. Moreover, the particle size of silica gel is large.

  Crystallization of silica tridymite is known to fuse alkali oxides, but existing tridymite crystals are formed by drastic environmental changes from ultra-high temperatures and high pressures such as meteorites and volcanic eruptions. So far, no method has been conceived so far in which artificially directly from a solution can be created in a short time.

  With the reduction in weight of automobiles and downsizing of industrial equipment, improvement in heat resistance of organic polymer materials is required. Although composite materials by adding fillers such as glass fibers and aggregates have been proposed, the heat resistance and recyclability of organic polymer materials themselves have not been solved.

  With the weight reduction of automobiles, the adoption of light and strong high-tensile steel sheets is urgently required. However, because of hot forming, measures against the generation of scale and new rust prevention methods are required.

  As the combustion temperature of automobiles rises, surface oxidation resistance such as EGR that circulates exhaust gas is required. However, the corresponding stainless steel material has a significant cost increase due to a rise in materials such as Ni.

  In recent years, co-generator power generation is often used, but exhaust gas is used and turbine corrosion is severe. For this reason, a high-temperature heat-resistant coating (Thermal Barrier Coat) such as chromium diffusion treatment (MCrAlY or CoNiCrAlY) is used. However, the wear of Al is the lifetime.

  In recent years, the Sol-Gel (sol-gel) method has been used as a method for producing a low temperature formed ceramic film. However, in the sol-gel method, the lifetime of the sol is very short, and a heating step is added after the gel is formed. The life of the constituent solution of the composition is several years and is semi-permanent.

In recent years, an organic binder that forms a molded article body with aggregate and an organic binder, impregnates it with alkoxysilanes, then dries it and bakes it at a high temperature to obtain a refractory molded article. It has been proposed (Patent Document 2: Japanese Patent No. 3139918).
However, this method requires a step of impregnating a molded article body with an alkoxylane solution, and there is a problem that the step becomes complicated.

Furthermore, a method has been proposed in which a molded product body is molded with an aggregate and an organic binder, an alkoxysilane is applied on the surface of the molded product, impregnated, dried, and cast. No. 143983).
On the other hand, in Patent Document 4 (Japanese Patent Laid-Open No. 2006-82413), a surface film mainly composed of an alkoxide such as silicon and / or a partial polycondensate thereof (A) is reacted with (A) on a substrate. A coating film excellent in stain resistance having a lower layer film mainly composed of a binder resin (B) such as a urethane resin having a functional group has been proposed, but this coating film is only composed of two layers. It is not an inorganic-organic composite hybrid film.
Patent Document 5 (Japanese Patent Laid-Open No. 7-68217) proposes a coating method for a metal surface in which a liquid compound containing a hydrolyzate of alkoxysilane and a polyester resin is applied to the metal surface and then dried. Has been. However, this coating method also uses an organic solvent-based solution of an already polymerized polyester resin and an alkoxysilane hydrolyzate, and the resulting film is simply a blend of an alkoxysilane condensate and a polyester resin. It is not an inorganic-organic hybrid film.

Special table 2007-520407 gazette Japanese Patent No. 3139918 JP 2002-143983 A JP 2006-82414 A JP-A-7-68217

In view of such circumstances, the present invention can achieve the following objectives, refractory molding using a composition having a reduction / catalytic reaction of alkali metal ions or alkaline earth metals that can be mixed with any substance. The purpose is to provide goods .
(A) A polymer material monomer or polymer is mixed with the above composition in powder form to improve the heat resistance characteristics and physical properties of the polymer material at 300 ° C. or higher, thereby obtaining a new functional material.
(B) The above composition is mixed with any object to improve hydrophilicity, anti-condensation, heat resistance, etc. (the object may be an organic material such as paper or wood).
(C) The above composition is added to the molten aluminum alloy, and an improvement treatment with an alkali metal ion or an alkaline earth metal is performed.
(D) The alkali metal ion or alkaline earth metal of the object mixed with the composition is removed with a halogen gas to obtain the insulating properties, corrosion resistance, and weather resistance of the composition.
(E) The composition is heated to about 800 ° C., the composition is liquefied, and the material is melt coated to obtain a heat and corrosion resistant film.
(F) The composition is adhered to a metal surface and heated at a high temperature of 800 ° C. or higher to form a reducing film to prevent scale formation during hot forming and heat treatment operations.
(G) The above composition is adhered to a metal surface, fired at a high temperature of 800 ° C. or higher in an atmosphere, vacuum, or inert gas atmosphere to remove alkali metal ions or alkaline earth metals, and tridymite Obtain crystals to obtain Thermal Barrier Coat.
(H) Aggregate is molded using the composite of the composition and the polymer material as a binder to obtain a refractory material of the composition.
(I) An aggregate is formed using a polymer material mixed with the above composition as a binder, and a refractory obtained by heating and baking at 800 ° C. or higher is obtained.

The present invention includes (a) a metal alkoxide of Group 4A of the periodic table, a metal alkoxide of Group 4B (excluding carbon), a metal alkoxide of Group 3A of the periodic table, a metal alkoxide of Group 3B of the periodic table, and these Mixing an alcohol solution containing at least one metal alkoxide selected from the group of partial hydrolysates of the above, an alkali metal alkali compound and / or an alkaline earth metal alkali compound, and (b) refractory particles Then, (c) relates to a method of mixing and molding an organic polymer material as a binder and heating to obtain a refractory molded article.
Here, the metal alkoxides constituting the (a) alcohol solution has the general formula _{R m Si (OR) 4-} m ( wherein R is mutually identical or different alkyl groups having 1 to 6 carbon atoms, a carbon An aryl group having 6 to 8 carbon atoms, an alkoxyalkyl group having 2 to 6 carbon atoms, or an aryloxyalkyl group having 7 to 12 carbon atoms, and m is an integer of 0 to 3). It is desirable to be one or two or more silicate esters selected from esters and these partial hydrolysates.
As an alkali metal alkali compound, sodium alcoholate or a hydroxide thereof is desirable.
The content of the alkali metal alkali compound and / or alkaline earth metal alkali compound in the alcohol solution is preferably 6 to 20% by weight in terms of alkali metal and / or alkaline earth metal.
The content of metal alkoxides in the alcohol solution is desirably 2 to 30% by weight in terms of metal oxide.
Furthermore, an organic amine compound may be added to the alcohol solution forming the composition of the present invention as a curing accelerator in an amount of 1 to 10% by weight based on the metal alkoxide.

Examples of the refractory particles (B) include at least one selected from sand such as silica sand and mullite.
Examples of the organic polymer material as the (C) binder include at least one selected from a phenol resin, an alkali phenol resin, and a phenol urethane resin.
The blending amount of the above (b) refractory particles is (b) 15 to 25 parts by weight with respect to 100 parts by weight of the alcohol solution. (C) The blending amount of the organic polymer material is (b) with respect to the refractory particles. 1.0 to 3.0% by weight.
In the present invention, it is preferable that (a) an alcohol solution and (b) refractory particles are mixed, and then the alcohol is dried and removed from the mixture.
Furthermore, the heating temperature is 800 ° C. or higher.
Next, this invention relates to the refractory molded article obtained by the method of obtaining the above refractory molded article.
A specific example of the above refractory molded product is a mold.

According to the present invention, a composition that maintains alkali metal or alkaline earth metal reactivity, such as reducing ability or catalytic ability, is physically mixed with any substance to obtain an inorganic-organic hybrid functional material. In addition, the reduction reactivity of alkali metal or alkaline earth metal can be utilized at normal temperature and normal pressure, thereby simplifying the process. Further, the composition forms a black molten composition at a high temperature of 800 ° C. or higher, and forms an oxidation-resistant and corrosion-resistant film on the surface of the object. Furthermore, when the boiling point is higher than the boiling point of the alkali metal or alkaline earth metal, the alkali metal or alkaline earth metal is removed, and a white, translucent tridymite crystal is obtained.
Therefore, after mixing (b) refractory particles with (b) the alcohol solution, and then molding (c) an organic polymer material as a binder and firing, a refractory molded product such as a mold is obtained. can get. The refractory molded article obtained by the present invention is an inorganic-organic hybrid refractory functional material, and can simplify the refractory manufacturing process.

It is the schematic which showed the behavior of Na ion in a silica crystal space | gap. Na ions by reducing silica and oxidized to produce a Na 2 _O, which is a photograph of the silica composition melt of. It is the graph which showed the thermal-analysis result (778.91 degreeC: reduction | restoration of a silica, 882.91 degreeC. The production | generation of an alkali oxide, 1044.96 degreeC: evaporation of Na ion) of a silica composition. It is the figure which showed the result of the X-ray diffraction of the cristobalite and (beta) -tridymite transition of a silica composition. It is an enlarged photograph of the silica composition by EPMA. It is a figure which shows the result of the thermal analysis of the organic silica compound by reaction of the said composition and a high molecular compound. It is a figure which shows the heat resistance of the polymeric material which produced | generated the organic silica compound. It is a figure which shows the heat resistant film in 1600 degreeC. It is a figure which shows the scale prevention function of the low carbon steel in 950 degreeC. It is a figure which shows the corrosion prevention effect in hydrogen sulfide atmosphere. The figure which shows the state (left figure) which showed the state where the black wrinkles adhered to the mold surface which did not apply MX solution, and the state where the white wrinkles adhered to the mold surface which applied MX solution, and the state where the white wrinkles peeled off It is a figure (left figure).

The above composition containing an alkali metal or an alkaline earth metal in the crystal nucleus voids is composed of a metal alkoxide of Group 4A of the periodic table, a metal alkoxide of Group 4B (excluding carbon), and a metal of Group 3A of the periodic table An alcohol solution containing at least one metal alkoxide selected from an alkoxide, a Group 3B metal alkoxide, and a partial hydrolyzate thereof, and an alkali metal alkali compound and / or an alkaline earth metal alkali compound; It is obtained by removing the alcohol of the solution as the main component by drying.
The above composition of the present invention can be used as an α-tridymite crystal nucleus using an alkali metal or alkaline earth metal as a nucleus without oxidizing the alkali metal or alkaline earth metal in the presence of the alcohol at the boiling point of the alcohol. It is a composition produced and incorporating an alkali metal or an alkaline earth metal into the crystal nucleus voids.

The alcohol solution that forms the composition of the present invention contains, as a component in an alcohol solvent, a general formula R _m M ₁ (OR) _4-m or M ₂ (OR) ₃ (where M ₁ is a periodic table 4A). A group 4B metal other than the group or carbon, M ₂ represents a metal of group 3A or 3B of the periodic table, R is the same or different alkyl group having 1 to 6 carbon atoms, 6 to 8 carbon atoms An aryl group, an alkoxyalkyl group having 2 to 6 carbon atoms, or an aryloxyalkyl group having 7 to 12 carbon atoms, and when M ₁ is Si, m is an integer of 0 to 3, and M ₁ is other than Si In the case of m = 0, at least one metal alkoxide selected from alcohol-soluble metal alkoxides and partial hydrolysates thereof, and the following general formula M ₃ OR ′ or M ₄ (OR ) ₂ (only , Wherein M ₃ represents represents an alkali metal, M ₄ represents an alkaline earth metal, R'is .R represents a hydrogen or an alkyl group having 1 to 6 carbon atoms is represented by the same as above.) And an alcohol-soluble alkali compound.

In the present invention, the metal alkoxide constituting the component of the composition is a metal alkoxide of a group 4B or a group 4B metal M ₁ other than carbon or a metal M ₂ of a group 3A or 3B of the periodic table other than carbon or a metal alkoxide thereof. It is a partial hydrolyzate. Here, examples of the metal M ₁ forming the metal alkoxide include Ti and Zr as the group 4A metal of the periodic table, and Si, Ge, Sn, Pb as the group 4B metal other than carbon. As M ₂ , Sc, Y and the like can be mentioned as the Group 3A metal of the periodic table, and B, Al, Ga and the like can be mentioned as the Group 3B metal.

  Moreover, R which forms the metal alkoxide is the same or different from each other, an alkyl group having 1 to 6 carbon atoms, an aryl group having 6 to 8 carbon atoms, an alkoxyalkyl group having 2 to 6 carbon atoms, or an alkyl group having 7 to 12 carbon atoms. An aryloxyalkyl group; Specifically, as the alkyl group, methyl group, ethyl group, propyl group, isopropyl group, amyl group, hexyl group, cyclohexyl group, butyl group, isobutyl group, t-butyl group, s-butyl group, etc. As the aryl group, a phenyl group, a tolyl group, a xylyl group, etc., and as the alkoxyalkyl group, a methoxyethyl group, a methoxyisopropyl group, a methoxypropyl group, a methoxybutyl group, an ethoxyethyl group, an ethoxypropyl group, an ethoxy group Examples of the butyl group include aryloxyalkyl groups such as phenoxymethyl group, phenoxyethyl group, phenoxypropyl group, phenoxybutyl group, triroxymethyl group, triloxyethyl group, triloxypropyl group, and triloxybutyl group. Can be mentioned.

The partial hydrolyzate of such a metal alkoxide is not particularly limited as long as it has a hydrolysis rate of 0% or more and can be dissolved in an alcohol solvent. The partial hydrolyzate may be a cyclic partial hydrolyzate.
Furthermore, these metal alkoxides and metal alkoxides composed of partial hydrolysates thereof may be used alone or as a mixture of two or more.

In the present invention, most preferred are the formula _{R m Si (OR) 4-} m ( wherein R is mutually identical or different alkyl groups having 1 to 6 carbon atoms, 6 carbon atoms as the metal alkoxides An aryl group having 8 carbon atoms, an alkoxyalkyl group having 2 to 6 carbon atoms, or an aryloxyalkyl group having 7 to 12 carbon atoms, and m is an integer of 0 to 3), and One or two or more silicate esters selected from these partial hydrolysates.

  Specifically, as tetraalkoxysilane, tetramethoxysilane, tetraethoxysilane, tetrapropoxysilane, tetraisopropoxysilane, tetrabutoxysilane, methoxytriethoxysilane, dimethoxydiethoxysilane, ethoxytrimethoxysilane, methoxytriisopropoxy Silane, dimethoxydiisopropoxysilane, methoxytryptoxysilane and the like, and examples of the alkyltrialkoxysilane include methyltrimethoxysilane, methyltriethoxysilane, methyltripropoxysilane, methyltriisopropoxysilane, and methyltripoxysilane. Toxisilane, ethyltrimethoxysilane, ethyltriethoxysilane, ethyltriisopropoxysilane and the like can be mentioned.

  Examples of the dialkyl dialkoxysilane include dimethyldimethoxysilane, dimethyldiethoxysilane, dimethyldipropoxysilane, dimethyldiisopropoxysilane, dimethyldibutoxysilane, diethyldimethoxysilane, diethyldiethoxysilane, and diethyldiisopropoxysilane. Examples of the trialkylalkoxysilane include trimethylmethoxysilane, trimethylethoxysilane, trimethylpropoxysilane, trimethylisopropoxysilane, trimethylbutoxysilane, triethylmethoxysilane, triethylethoxysilane, triethylisopropoxysilane, and the like. it can.

  Furthermore, examples of the aryloxy silane include tetraphenoxy silane and tetratrioxy silane. Examples of the alkyl aryloxy silane include methyl triphenoxy silane, ethyl triphenoxy silane, dimethyl diphenoxy silane, diethyl diphenoxy silane, And methyltritriloxysilane.

  Furthermore, examples of the alkoxyalkylsilane include tetramethoxymethylsilane, tetramethoxyethylsilane, tetramethoxyisopropylsilane, tetraethoxymethylsilane, tetraethoxyethylsilane, tetraethoxyisopropylsilane, and the like, and aryloxyalkylsilane. Examples thereof include tetraphenoxymethyl silane, tetraphenoxyethyl silane, tetraphenoxypropyl silane, tetraphenoxyisopropyl silane, and tetratrioxyethyl silane.

  Other preferable metal alkoxides include tetrabutoxy titanium, tetrabutoxy zircan, triisopropoxyaluminum and the like.

The content of these metal alkoxides in the alcohol solution forming the composition of the present invention is preferably _{2 in} terms of metal oxide (for example, in terms of SiO ₂ when the metal alkoxide is a silicate ester). It should be in the range of -50% by weight, more preferably 2-30% by weight, most preferably 10-30% by weight. If the content is less than 2% by weight, the content of the metal oxide derived from the metal alkoxides may be insufficient when the composition is formed, and the composition may not be formed. From this point, the dissolution amount of the alkali compound may be less than 0.5% by weight and may not satisfy the purpose of the composition. The metal oxide may be referred to as “metal oxide which is a complete hydrolysis condensate of metal alkoxides”. Moreover, the range of 15-25 weight% may be sufficient.

As for the alkali compound, which is another component of the alcoholic solution, a metal M ₃ are, there may be mentioned lithium, sodium, potassium, etc., preferably include sodium, potassium. As the metal _{M 4} can be mentioned Ca, Sr, Ba, and Ra. In addition, the substituent R ′ forming the alkali metal alkoxide includes hydrogen or methoxy group, ethoxy group, propoxy group, isopropoxy group, butoxy group, pentyloxy group, hexyloxy group, cyclohexyloxy group and the like. -6 alkyl groups, phenoxy groups, triloxy groups, alkoxyalkyl groups, or aryloxyalkyl groups. One of these alkali compounds may be used alone, or a mixture of two or more thereof may be used.

  Thus, the solution used in the present invention is characterized in that an alkali compound such as sodium alcoholate or a hydroxide thereof is added to an alkyl silicate or an allyl silicate partial hydrolyzate in an alcohol solvent. And Sodium alcoholate is a strong alkali, but can be dissolved uniformly without hydrolyzing metal alkoxides such as alkyl silicate or allyl silicate. The curing mechanism of the composition of the present invention is presumed as follows.

That is, in the process of removing alcohol in a solution in which, for example, sodium ethylate (C ₂ H ₅ ONa) as sodium alcoholate, for example, ethyl silicate as alkyl silicate is partially hydrolyzed and mixed with alcohol, alcohol near the boiling point of alcohol is removed. In the presence, SiO ₂ crystallizes with Na ions as nuclei without oxidation of Na.

  The content of the alkali compound in the composition of the present invention is preferably 1 to 25% by weight, more preferably 5 to 25, in terms of metal (for example, Na when the metal of the alkali compound is sodium). % By weight, most preferably in the range of 6-20% by weight. If it is less than 1% by weight, the solution becomes acidic and becomes silica gel, the content of the metal oxide derived from the alkali metal alkoxide is insufficient, and the desired composition may not be formed. On the other hand, if it exceeds 25% by weight, When the volume of the alkali metal and / or alkaline earth metal exceeds the volume of the voids of the crystal formed by the metal derived from the metal alkoxide, and the above composition with the alkali metal and / or alkaline earth metal as the core is not formed There is. Moreover, the range of 6-10 weight% may be sufficient.

  Furthermore, examples of the alcohol solvent for dissolving the metal alkoxides and alkali compounds as the components of the solution include, for example, methyl alcohol, ethyl alcohol, propyl alcohol, isopropyl alcohol, butyl alcohol, isobutyl alcohol, amyl alcohol, hexyl alcohol, cyclohexyl alcohol, and ethylene. Examples include glycol, diethylene glycol, propylene glycol, ethyl cellosolve, methyl cellosolve, propyl cellosolve, butyl cellosolve, phenylmethyl cellosolve, and phenylethyl cellosolve.

  Further, by mixing the composition according to the present invention with an organic polymer material, a composite of the composition and the organic polymer material is formed by a damping bond by reduction reaction of alkali metal or alkaline earth metal. Thus, weather resistance and heat resistance different from those of conventional organic polymer materials can be added.

When a two-component resin is used as the organic polymer material for mixing the composition of the present invention, it is mixed with a monomer. The mixing ratio is adjusted depending on the application. The addition to the thermoplastic resin may be mixing with the monomer or kneading with the polymer.
The composition of the present invention forms a composite with an organic polymer material and improves the heat resistance, weather resistance, and mechanical properties of the substrate.

Examples of organic polymer materials include olefin resins such as polyethylene, polypropylene, and polystyrene, polyamide resins such as nylon 6, nylon 6, 6, and the like, epoxy resins, polyester resins such as polyethylene terephthalate, polypropylene terephthalate, and polybutylene terephthalate, ethylene-α -Olefin copolymer [EP (D) M] etc. are mentioned, and heat resistance strength is improved by mixing the said composition of this invention.
As the two-component resin, an epoxy resin, a urethane resin, a polyester resin, a phenol resin, or the like can be used.

In addition, in order to increase the reducibility of the alkali metal and / or alkaline-earth metal of the said composition of this invention, an amino organic compound can be added to an alcohol solution. Examples of the amino organic compound include silane coupling agents such as aminosilane, ureidosilane, and epoxysilane. Here, when a silane coupling agent is used, the crosslinking point is controlled by a two-point crosslinked silane (such as dimethylethoxysilane) and a three-point crosslinked silane (such as trimethoxysilane). It is preferable to prevent the occurrence of cracks accompanying shrinkage. It is preferable to use the silane coupling agent by dissolving or dispersing it in water and / or an organic solvent and adding it to the solution.
Examples of the organic solvent used for the above purpose include alcohol solvents. The amount of the silane coupling agent used is generally about 1 to 10% by weight, preferably three-point crosslinked, based on the solution, with two-point crosslinked silane and three-point crosslinked silane based on the metal alkoxide. It is preferable to control 1 to 5% by weight of silane and 1 to 3% by weight of 2-point cross-linked silane.

In addition, the solution forming the composition may contain additives other than those described above for various purposes. For example, by adding dialkoxysilane and / or silicone oil, adjusting the surface tension of the object, The caking property of the object can be improved. Examples of dialkoxysilane include 3-aminopropylmethyldimethoxysilane.
The addition amount of dialkoxysilane and / or silicone oil is preferably 1 to 5% by weight in total with respect to the metal alkoxides of the solution of the present invention.

Furthermore, organic substances and inorganic fine particles (hereinafter also referred to as “fine particles”) can be added to the solution forming the composition of the present invention.
The organic substance that can be added is preferably polyethylene glycol, and the inorganic fine particles are preferably fumed silica, ZrO ₂ , TiO ₂ , or Al ₂ O ₃ . The amount of these additives is 1 to 10% by weight, preferably 1 to 5% by weight, although it depends on the specific gravity and particle size of the additive with respect to the metal alkoxides of the solution of the present invention.

In order to remove the alcohol from the alcohol solution, a drying treatment can be performed at any temperature between room temperature and the boiling point of the alcohol in any atmosphere in the atmosphere, under vacuum, or in an inert gas, preferably Is 40-60 ° C. Furthermore, in order to obtain a crystal nucleus, it can heat at 120-150 degreeC for 40-60 minutes. The flaky composition thus obtained is pulverized to a particle size suitable for each application, but is preferably 120 mesh or more for use in the kneading into a resin.
The powdery composition of the present invention may be dried and powdered at the same time to form a fine powdery composition by micronizing the alcohol solution by air mixing atomization. Further, it may be formed into a fine particle by high temperature spraying such as plasma. The formed powder or powdery film can impart high temperature oxidation resistance to the metal surface.

In the process of removing alcohol by drying, the alkali metal or alkaline earth metal of the composition is taken into the crystal nucleus of the metal. When alkali metal or alkaline earth metal and the metal that forms crystal nuclei are a combination of Na and SiO ₂ , the blending ratio of Na / SiO ₂ = 0.3 to 1.0 is effective as a reducing agent during the production of the composition. It is preferable to maintain.

  In addition, the alkali metal or alkaline earth metal in the composition is subjected to heat treatment at 780 to 850 ° C. for 30 to 60 minutes, expansion of crystal voids during the temperature rising process, and expansion of the alkali metal or alkaline earth metal. As a result, it leaks out of the crystal and produces alkali oxide, resulting in the black melt shown in FIG. FIG. 1 shows a process in which the melt is formed when Na is used as the alkali metal. By applying this molten composition to a metal surface such as an aluminum alloy, cast iron, or steel by plasma melt coating, an oxidation resistance and corrosion resistance film can be formed. When apply | coating a composition to a metal, a preferable application quantity is a dry film thickness, and is 50-100 micrometers normally.

When the molten black composition is further heated, the alkali metal or alkaline earth metal reaches the boiling point, and starts boiling and evaporating. FIG. 3 shows an example of the thermal analysis of the above reaction. Alkali metal or alkaline earth metal is evaporated and removed by rapid boiling to form white and translucent tridymite crystals shown in FIG.
Further, this α-tridymite crystal changes to β-tridymite crystal at 900 ° C. or higher (FIG. 4), and forms a composition having heat resistance, corrosion resistance, and insulating properties that are ceramic characteristics up to a high temperature region of 1600 ° C. .

  Taking advantage of this feature, a metal workpiece is heated to 150 to 200 ° C., and the composition is sprayed onto a metal surface such as cast iron or steel to a thickness of 0.1 to 2 μm, and the metal is heated under the above conditions. Then, the alkali metal or alkaline earth metal in the composition is removed on the metal surface, and an oxidation resistant and corrosion resistant film can be formed.

The composition of the present invention can be mixed in any object at room temperature. The object may be an organic material such as an organic polymer material, paper, or wood, in addition to a metal. Since the object formed by mixing the above composition of the present invention is hydrophilic, a hybrid object of heat-resistant ceramics such as prevention of condensation and antistatic is generated.
The mixing amount when the composition of the present invention is mixed with these objects depends on the particle size of the composition and the viscosity of the object, but the particle size of the composition is about 200 mesh and the viscosity of the object is In the case of about 3000 cp, the maximum is 45% by weight, and in the case where the particle size of the object is 325 mesh or more, the maximum is preferably about 10%.

Moreover, the said composition is mixed with a refractory grain, the monomer and / or polymer which form the organic polymer material as a binder are added, and it shape | molds, and when fired, a fire-resistant molded article will be obtained. In the conventional refractory molding method, since the molded product is immersed in an organic binder and baked, there is a problem in that the binder moves to the surface during drying and a uniform strength cannot be obtained. The molded product produced by mixing the composition of the present invention is an inorganic-organic hybrid functional material, and since it is in a powder form, it can be directly mixed with a refractory, and molded and fired. The refractory manufacturing process can be simplified.
Examples of the refractory particles include silica sand and mullite. The organic polymer material as a binder to be added is preferably a phenol resin, an alkali phenol resin, or a phenol urethane resin, and can be added in an amount of 1.0 to 3.0% by weight with respect to the refractory particles as an aggregate .

  Moreover, sand coated with the composition can be obtained by blending sand into the alcohol solution forming the composition of the present invention and then removing the alcohol. The drying condition when sand is blended can be dried at any temperature from ambient temperature to the boiling point of the alcohol in the atmosphere, under vacuum, or in an inert gas atmosphere, preferably 40-60 ° C. Furthermore, in order to obtain a crystal nucleus, it can heat at 120-150 degreeC for 40-60 minutes. The ratio of the sand to be blended is preferably 15 to 25 parts by weight with respect to 100 parts by weight of the alcohol solution before blending the sand. Sand may be added to the composition of the present invention.

Furthermore, an organic polymer material can be added as a binder to the coated sand and molded into a mold. When the mold formed in this way is in contact with the molten metal, it instantaneously changes to tridymite crystals, and a mold having stable heat resistance up to 1470 ° C. can be obtained. The mold can be fired after molding. Examples of the binder to be used include phenol resin, phenol urethane resin, and alkali phenol resin, and the addition amount is desirably 1.5 to 2.2% by weight with respect to sand.
In addition, the heating temperature after shaping | molding is 800 degreeC or more normally.

  In addition, since the alkali metal or alkaline-earth metal resulting from the alkali compound used for this invention remains on the surface of the object which mixed the said composition of this invention, if necessary, water or ethanolamine It is preferable to wash with an aqueous solution. By this washing, for example, when the alkali metal is sodium, sodium atoms can be removed from the surface of the object as a sodium hydroxide aqueous solution or a sodium carbonate aqueous solution.

The present invention is a method for suppressing the generation of a black soot-like substance or black tar-like substance that occurs when a material containing a polymer containing an aromatic compound as a repeating unit is heated at high temperature in the presence of oxygen, (A) Before heating the material, the metal alkoxide of group 4A of the periodic table, the metal alkoxide of group 4B (excluding carbon), the metal alkoxide of group 3A of the periodic table, the metal alkoxide of group 3B of the periodic table And alcohol in an alcohol solution containing at least one metal alkoxide selected from the group of these partial hydrolysates and an alkali compound of an alkali metal and / or an alkali compound of an alkaline earth metal is removed by drying. Before adding the resulting composition to (a1) the material, or (a2) adhering to the surface of the material, or (B) heating the material, Periodic Table 4 Selected from the group consisting of group A metal alkoxides, group 4B (excluding carbon) metal alkoxides, group 3A metal alkoxides, group 3B metal alkoxides, and partial hydrolysates thereof. An alcohol solution containing at least one metal alkoxide and an alkali metal alkali compound and / or alkaline earth metal alkali compound is added to the material (b1), or (b2) is attached to the surface of the material. Then, there is provided a method for suppressing the treatment by drying and removing the alcohol in the alcohol solution.
This invention is the said suppression method, The polymer which uses an aromatic compound as a repeating unit is a phenol resin or a phenol urethane resin, and content of the polymer which uses the aromatic compound in a raw material as a repeating unit is 10 Mass% or less, high-temperature heating is heating at 400 ° C. or higher,
Provided is a suppression method for performing the process (b2) of (B).

The polymer having an aromatic compound as a repeating unit is not particularly defined, and examples thereof include a phenol resin, a phenol urethane resin, and an alkali phenol resin, and any one of them may be included.
The temperature at which the material is heated at a high temperature is not particularly limited as long as it is a temperature at which a black soot-like substance or a black tar-like substance is generated when heated, and examples thereof include 400 ° C. or more.
The content of the polymer having an aromatic compound as a repeating unit in the material is not particularly limited, but may be 10% by mass or less.
“Adding to the material” the composition or the alcohol solution may be added to the material regardless of the state of the material. For example, it may be put in a thermoplastic resin and then cured. In addition, it may be mixed with an oily or highly viscous liquid or gel composition.

“Adhering the composition or the alcohol solution to the surface of the material” means that when the material is a solid, it may be adhered to the surface of the solid. May be immersed in a solution containing the composition or the alcohol solution.
The problem of the above suppression method is that even when heated to 1000 ° C. or higher in order to remove only the polymer compound having a benzene ring from the material containing the polymer compound having a benzene ring, It is to overcome the problem that a substance is generated and this black soot-like substance and black tar-like substance cannot be easily removed.

The effect of the above suppression method is to suppress the generation of black soot-like substance and black tar-like substance when removing only the polymer compound having benzene ring from the material containing the polymer compound having benzene ring, or simply An object of the present invention is to provide a material that does not contain a polymer compound having a benzene ring from a material that contains a polymer compound having a benzene ring so that it can be removed. Moreover, since generation | occurrence | production of a black soot-like substance and a black tar-like substance can be suppressed or removed easily, when using as a casting_mold | template, it is providing the clean castings without the casting_mold | template after use being dirty.
Such an effect is considered to be due to the catalytic effect of sodium ions. In the present invention, sodium ions can be supplied, stored and used safely and easily.

  Hereinafter, the present invention will be described more specifically with reference to examples.

Reference example 1
200 g of tetraethoxysilane (produced by Wacker, ethyl silicate 40) is dispensed into a sealable mixing vessel having an internal volume of 2 liters, 100 g of i-propyl alcohol is added thereto, and 10 g at room temperature in a sealed state using a stirrer. Stir for 30 minutes and then hydrolyze tetraethoxysilane by stirring for 30 minutes at 25 ° C., and then keep sealed at 25 ° C. for 6 hours, hydrolyzing tetraethoxysilane with a hydrolysis rate of 30% Was prepared.
Next, 35.1 g of a 21 wt / wt% C ₂ H ₅ ONa ethanol solution and 344.9 g of i-propyl alcohol were added to this tetraethoxysilane hydrolyzed solution, and the mixture was sealed in a sealed state using a stirrer. Stir at 30 ° C. for 30 minutes to prepare a solution. This solution is referred to as MX solution. This MX solution is an alcohol (i-propyl alcohol) solution having a metal alkoxide content of 20 wt% in terms of SiO ₂ and an alkali metal alkali compound content of 6 wt% in terms of Na.
This MX solution was dried in air at 60 ° C. for 24 hours, and then heat-treated at 80 ° C. for 60 minutes to completely remove the alcohol solution and further to obtain low-temperature tridymite crystals at 200 ° C. for 60 minutes. Heat treatment was performed to obtain the flaky composition. Furthermore, it grind | pulverized and the said composition was made into the powder form of about 150 mesh.

8% by weight of the above composition in powder form is mixed with No. 7 silica sand as refractory particles, and 2% by weight of phenol urethane resin, phenol resin or epoxy resin is added as an organic polymer material, and 100% by weight. The three test pieces having a size of 10 × 10 × 50 mm were formed. The test piece was heated to 1,000 ° C. for 60 minutes every 100 ° C., and a hot bending test at each temperature was performed.
As a result of the test, as shown in FIG. 7, the test piece containing the composition of the present invention is 200 ° C. to 300 ° C. in comparison with the test piece to which only the conventional resin not containing the composition of the present invention is added. It showed high strength at ° C. As described above, it was confirmed that the composition of the present invention adds bending strength at high temperatures to a molded article composed of refractory particles and an organic polymer material as a binder.
Moreover, in the differential thermal test (FIG. 6) using said test piece which mix | blended the composition of this invention, silica sand, and a phenol resin, the production | generation of the organic silica compound in 200 degreeC, and the thermal decomposition of the organic silica compound in 400 degreeC. Was confirmed.

Reference example 2
A metal having a film having a thickness of about 2 μm containing the above composition was formed by spraying the MX solution of Reference Example 1 on the surface of a 304 stainless steel piece of 300 × 400 × 20 mm, and then drying and removing the alcohol. I got a piece. This metal piece was set as a cold gold in a mold, and a molten high manganese steel of 1600 ° C. or higher was cast.
As a result, as shown in FIG. 8, no weld between the molten metal and cold gold was observed, and no defects caused by condensation were observed. The film prevents condensation at room temperature, and the composition of the present invention contained in the film is exposed to a high temperature by contact with molten high manganese, so that the crystal form of silica is transformed into β-tridymite crystals, thereby forming the film. It is thought that heat resistance was imparted to. As described above, it was confirmed that when the composition of the present invention was used as a mold, a good casting without defects was obtained without requiring complicated treatment.

Reference example 3
A 2 μm film was formed by spraying the composition onto a part of the surface of a 100 × 100 × 5 mm piece of a low carbon steel metal piece with the MX solution and then drying off the alcohol. This metal piece was heat-treated at 950 ° C. for 60 minutes and tested for oxidation resistance.
As a result of the test, as shown in FIG. 9, a large amount of scale was generated where no coating was applied, but no oxidation was observed in the coated portion. It was confirmed that high temperature oxidation resistance can be imparted to a metal by using the composition of the present invention as a film.

Reference example 4
A film was formed by spraying the MX solution onto a 30Φ × 50 mm 304 stainless metal piece and then drying off the alcohol. Along with 304 stainless steel pieces not subjected to the above treatment, it was heated at 700 ° C. for 36 hours in a hydrogen sulfide atmosphere.
As a result, as shown in FIG. 10, the surface of the test piece not coated with the composition of the present invention was severely corroded, while the coated test piece did not corrode and had high corrosion resistance at high temperatures. Indicated. This is considered to be the effect of the reducing action of sodium on the composition.

Example 1
No. 7 silica sand was added to the MX solution and dried in the atmosphere at 40 ° C. for 60 minutes to form foundry sand coated with the above composition. A test piece having a size of 10 × 10 × 50 mm was formed by adding 2% of the foundry sand to the foundry sand using phenol urethane resin as an organic binder. About the said test piece, the hot bending test similar to the reference example 1 was done. Although the strength of the conventional organic mold rapidly decreases with increasing temperature, it was confirmed that the test piece formed by the above method improved the bending strength at high temperature as in Reference Example 1 .

Reference Example 5
〔Test method〕
Three components were mixed so that No. 7 silica sand was 98 wt%, phenol resin was 1 wt%, and isocyanate was 1 wt%. A cold box mold was prepared by kneading, shaping, and curing at room temperature under ventilation such that the amine generated by the chemical reaction between the components was vaporized.
The MX solution was applied to a part of the surface of the cold box mold and heated at 40 to 60 ° C. to dry and remove the alcohol. Next, a molten aluminum alloy at 700 ° C. was put into the cold box mold and cast to obtain a cast product.
The condition of the surface of the obtained casting and the condition of soot generated on the surface of the cold box mold after use were visually observed.
[Results and discussion]

The results are shown in FIG.
The black box is attached to the surface of the cold box mold not coated with the MX solution (the left figure in FIG. 11), and the cast product (aluminum alloy) cast by the surface portion of the cold box mold not coated with the MX solution. The surface of was dull. The black wrinkles were strongly attached and could not be removed by rubbing.
On the other hand, the surface of the cold box mold coated with the MX solution has white wrinkles (the right figure in FIG. 11), and the surface of the cast product (aluminum alloy) cast by the surface portion of the cold box mold coated with the MX solution. Shone white. This white cocoon was peeled off by just rubbing lightly (right figure in FIG. 11). This action is due to the catalytic effect of sodium ions contained in the composition obtained by drying and removing alcohol from the MX solution to further oxidize the benzene ring in the resin and the carbon fiber produced by the oxidation of the benzene ring. It is thought to be obtained by lowering the molecular weight (rather than the molecular weight of black wrinkles that occur when not used).

  Alkali metals and alkaline earth metals are known as powerful materials for reduction and catalysis, but they are considered to be extremely difficult to handle due to the severe reactivity at room temperature and normal pressure and the danger of storage and transportation. ing. The composition that maintains the reactivity of alkali metal and / or alkaline earth metal from room temperature to around 800 ° C. is a stable powdery composition and can be easily mixed with any object. By doing so, the reduction reactivity of alkali metal and / or alkaline earth metal can be added, and a new function can be added by mixing with the object. In recent years, new functions such as fuel cells and solar power generation are required for material technology. Many functional parts rely on rare materials such as rare metals. In particular, by utilizing the reactivity of alkali metals and / or alkaline earth metals as a catalyst, it can be expected that the present invention will be a raw material for new functional materials to replace rare materials such as rare metals. Further, by mixing the composition and the organic polymer material, the effect of Na ion dambling bonds and the formation of a composite having a heat resistance of 300 ° C. or higher by a reduction reaction can be achieved. It is possible to add. Furthermore, the separation of benzene ring carbon by the catalytic effect of Na ions in the temperature range of 400 ° C. to 700 ° C. makes it possible to use biomass fuel, treat exhaust gas, etc. at low temperatures. However, it satisfies the functional requirements in the temperature range of 300 ° C. to 700 ° C. which is not chemically maintained. Therefore, the composition for holding an alkali metal and / or alkaline earth metal of the present invention in a crystal nucleus is a new material technology utilizing the reactivity of alkali metal and / or alkaline earth metal from room temperature to 800 ° C. Specifically, by improving the high-temperature characteristics of polymer materials, insulating films, conductive films, functional materials in the electronic equipment industry, structural parts in the automobile industry, heat-resistant materials in the housing industry, anti-condensation materials It is useful for applications such as improvement treatment of aluminum in metal materials. Further, the composition becomes a black liquid at 800 ° C., and deodorization and desulfurization that can utilize the reactivity of alkali metal and / or alkaline earth metal by subjecting the composition in this state to a melt coating on the surface of the object. A film having functions such as oxidation resistance and heat resistance can be obtained.

Claims (12)

  (I) Periodic Table 4A Group metal alkoxide, Periodic Table 4B group metal alkoxide (except carbon), Periodic Table 3A group metal alkoxide, Periodic Table 3B group metal alkoxide, and partial hydrolysis thereof An alcohol solution containing at least one metal alkoxide selected from the group of products, an alkali compound of an alkali metal and / or an alkali compound of an alkaline earth metal, and (b) refractory particles, and then ( C) A method in which an organic polymer material as a binder is mixed and molded and heated to obtain a refractory molded product. The metal alkoxides general formula _{R m Si (OR) 4-} m ( wherein R is mutually identical or different alkyl groups having 1 to 6 carbon atoms, an aryl group having 6 to 8 carbon atoms, 2 carbon atoms 6 alkoxyalkyl groups or aryloxyalkyl groups having 7 to 12 carbon atoms, and m is an integer of 0 to 3), and partial hydrolysates thereof. The method for obtaining a refractory molded article according to claim 1, which is one or more silicate esters.   The method for obtaining a refractory molded article according to claim 1 or 2, wherein the alkali metal alkali compound is sodium alcoholate or a hydroxide thereof.   The content of an alkali metal alkali compound and / or alkaline earth metal alkali compound in the alcohol solution is 6 to 20% by weight in terms of alkali metal and / or alkaline earth metal. A method for obtaining a refractory molded article according to any one of the above.   The method for obtaining a refractory molded article according to any one of claims 1 to 4, wherein the content of the metal alkoxide in the alcohol solution is 2 to 30% by weight in terms of metal oxide.   The refractory molded article according to any one of claims 1 to 5, wherein the alcohol solution contains an organic amine compound, and the content of the organic amine compound is 1 to 10 wt% with respect to the metal alkoxide. How to get.   The method for obtaining a refractory molded article according to any one of claims 1 to 6, wherein the (b) refractory grains are selected from silica sand and mullite.   (C) The method for obtaining a refractory molded article according to any one of claims 1 to 7, wherein the organic polymer material as the binder is selected from a phenol resin, an alkali phenol resin, and a phenol urethane resin.   (B) The blending amount of the refractory particles is 15 to 25 parts by weight with respect to 100 parts by weight of the alcohol solution (b), and (c) the blending amount of the organic polymer material is (ro) with respect to the refractory particles. The method of obtaining the refractory molded article in any one of Claims 1-8 which is 1.0 to 3.0 weight%.   The method of obtaining the refractory molded article in any one of Claims 1-9 which dry-removes alcohol from a mixture after mixing (I) and (B).   The method of obtaining the refractory molded article in any one of Claims 1-10 whose said heating temperature is 800 degreeC or more. The method for obtaining a refractory molded article according to any one of claims 1 to 11, wherein the refractory molded article is a mold .

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