WO2018097179A1 - Sable enduit, son procédé de fabrication et procédé de fabrication pour moule l'utilisant - Google Patents

Sable enduit, son procédé de fabrication et procédé de fabrication pour moule l'utilisant Download PDF

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Publication number
WO2018097179A1
WO2018097179A1 PCT/JP2017/042007 JP2017042007W WO2018097179A1 WO 2018097179 A1 WO2018097179 A1 WO 2018097179A1 JP 2017042007 W JP2017042007 W JP 2017042007W WO 2018097179 A1 WO2018097179 A1 WO 2018097179A1
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Prior art keywords
coated sand
mold
water glass
water
coating layer
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PCT/JP2017/042007
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English (en)
Japanese (ja)
Inventor
哲也 浦
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旭有機材株式会社
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Priority to JP2018552616A priority Critical patent/JP7060519B2/ja
Priority to CN201780072058.9A priority patent/CN110099761B/zh
Publication of WO2018097179A1 publication Critical patent/WO2018097179A1/fr

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    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B22—CASTING; POWDER METALLURGY
    • B22C—FOUNDRY MOULDING
    • B22C1/00—Compositions of refractory mould or core materials; Grain structures thereof; Chemical or physical features in the formation or manufacture of moulds
    • B22C1/02—Compositions of refractory mould or core materials; Grain structures thereof; Chemical or physical features in the formation or manufacture of moulds characterised by additives for special purposes, e.g. indicators, breakdown additives
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B22—CASTING; POWDER METALLURGY
    • B22C—FOUNDRY MOULDING
    • B22C1/00—Compositions of refractory mould or core materials; Grain structures thereof; Chemical or physical features in the formation or manufacture of moulds
    • B22C1/02—Compositions of refractory mould or core materials; Grain structures thereof; Chemical or physical features in the formation or manufacture of moulds characterised by additives for special purposes, e.g. indicators, breakdown additives
    • B22C1/10—Compositions of refractory mould or core materials; Grain structures thereof; Chemical or physical features in the formation or manufacture of moulds characterised by additives for special purposes, e.g. indicators, breakdown additives for influencing the hardening tendency of the mould material

Definitions

  • the present invention relates to a coated sand, a method for producing the same, and a method for producing a mold using the same, and in particular, exhibits excellent strength even in a case where time has elapsed since moisture was added by adding water.
  • the present invention relates to a dry coated sand from which a mold can be advantageously obtained, a method for producing the same, and a method for producing a mold using such a coated sand.
  • the coated sand using water glass as a binder when molding a mold, in general, in the case of a wet state containing a large amount of moisture, it is left as it is. As for what exhibits a dry state, when moisture is added and the whole is wetted, it is filled into a predetermined mold, and the wet coated sand is used for a long time. If left as it is, the water glass in the coating layer is dried due to the evaporation of moisture, and the bonding between the coated sands becomes insufficient, resulting in a problem that the strength of the finally obtained mold is lowered.
  • Patent Document 1 Japanese Translation of PCT International Publication No. 2008-511447 (Patent Document 1), it is a molding material mixture for producing a mold for metal processing, either immediately after shaping or after long-term storage.
  • Patent Document 1 a molding material mixture comprising a binder based on at least one fire-resistant molding base material and one water glass, wherein the particulate material is selected from a group of silicon dioxide and the like. What is added with a metal oxide in a certain ratio is disclosed. And by adding such a predetermined particulate metal oxide, the molding material mixture disclosed therein has a high strength regardless of whether it is used immediately after shaping or after long-term storage. It is said that a mold can be manufactured.
  • the coated sand using water glass as a binder particularly those that are in a dry state, have a long time since the addition of moisture and when the moisture is added during mold molding. There is still room for development of the coated sand that can produce a mold that exhibits excellent strength, regardless of what has passed.
  • An object of the present invention is to provide a dry coated sand having room temperature fluidity, in which the state is maintained for a long time, and the finally obtained mold can exhibit excellent strength.
  • Another object of the present invention is to provide a method capable of advantageously producing such dry coated sand having room temperature fluidity.
  • the present invention can be suitably implemented in various aspects as listed below, and each aspect described below is employed in any combination. Is possible. It should be noted that aspects or technical features of the present invention are not limited to those described below, and can be recognized based on the inventive concept that can be grasped from the description of the entire specification. Should be understood.
  • the surface of the refractory aggregate is covered with a coating layer containing water glass, which is a dry coated sand having room temperature fluidity, and that the coating layer contains a moisturizing agent.
  • a characteristic coated sand A characteristic coated sand.
  • the coated sand according to the aspect (1) wherein the moisture content is 5 to 55% by mass of the solid content of water glass in the coating layer.
  • the content of the humectant is 1 of the solid content of water glass in the coating layer.
  • the aspect (1) which is 0.1 to 20.0 parts by mass with respect to 00 parts by mass Or the coated sand as described in said aspect (2).
  • Coated sand as described in (7) The coated sand according to any one of the aspects (1) to (6), wherein the refractory aggregate is spherical.
  • a method for producing dry coated sand having room temperature fluidity in which the surface of the refractory aggregate is covered with a coating layer containing water glass.
  • the surface of the refractory aggregate is covered with a coating layer containing water glass and a humectant by mixing a binder and a humectant mainly composed of glass and evaporating the water.
  • a method for producing a coated sand comprising producing a coated sand whose amount is 5 to 55% by mass of the solid content of water glass in the coating layer.
  • the coating layer covering the surface of the refractory aggregate contains a moisturizer together with water glass as a binder. Therefore, when moisture is supplied from the outside to be in a wet state, the wet state is maintained for a long time by the moisturizing agent contained in the coating layer. For this reason, the adhesiveness of the water glass can be effectively maintained until the mold is formed, so that the finally obtained mold exhibits excellent strength.
  • the amount of water added is minimized when the mold is formed using the coated sand of the present invention. Therefore, it is possible to enjoy the effect that the molded mold is excellent in releasability from the mold, and that the obtained mold has good disintegration.
  • the coated sand according to the present invention is generally prepared by mixing water glass in the state of an aqueous solution as a binder with the refractory aggregate and evaporating water from the mixture, in other words, an aqueous solution.
  • the surface of the refractory aggregate is produced by evaporating the water of the water glass in the state of It is formed in a dry state and has good room temperature fluidity.
  • the “dry coated sand having room temperature fluidity” in the present invention means a coated sand from which a measured value is obtained when the dynamic angle of repose is measured regardless of the moisture content.
  • This dynamic angle of repose means that the coated sand is accommodated in a cylinder whose one end in the axial direction is closed with a transparent plate (for example, in a container having a diameter of 7.2 cm and a height of 10 cm, its volume
  • the coated sand is flowing in the cylinder by holding the shaft center in the horizontal direction and rotating it around the horizontal axis at a constant speed (for example, 25 rpm).
  • the slope of the layer is flat and refers to the angle formed between the slope and the horizontal plane.
  • the dynamic repose angle of the coated sand according to the present invention is preferably 80 ° or less, more preferably 45 ° or less, and still more preferably 30 ° or less.
  • a coated sand having a dynamic angle of repose of 45 ° or less can be advantageously obtained by using a spherical refractory aggregate.
  • the slope of the coated sand layer is not formed as a flat surface, and as a result, the dynamic angle of repose cannot be measured, It will be referred to as wet coated sand.
  • the dry coated sand having room temperature fluidity according to the present invention has a moisture content of 5 to 55% by mass with respect to the solid content of water glass contained in the coating layer covering the surface of the refractory aggregate.
  • the corresponding amount is desirable, more desirably 10 to 50% by mass, and most desirably 20 to 50% by mass.
  • the moisture content in the coated sand is less than the amount corresponding to 5% by mass with respect to the solid content of the water glass in the coating layer, the water glass is vitrified and water is added again during the mold making. There is a possibility that it does not return to a solution state. On the other hand, if the amount exceeds 55% by mass, the coated sand may not be in a dry state.
  • the method according to types such as a water glass and a moisturizing agent, can be employ
  • the measuring method described in the column of Examples described later can be exemplified.
  • the refractory aggregate constituting the coated sand of the present invention is a refractory substance that functions as a base material of a mold, and any of various refractory granular or powder materials conventionally used for molds. Specifically, silica sand, recycled silica sand, special sand such as alumina sand, olivine sand, zircon sand, chromite sand, ferrochrome slag, ferronickel slag, converter slag, etc. Slag-based particles; artificial particles such as alumina-based particles and mullite-based particles; and regenerated particles thereof; alumina balls, magnesia clinker, and the like.
  • refractory aggregates may be fresh sand, or reclaimed sand or recovered sand that has been used once or a plurality of times as casting sand for casting molds. Even mixed sand made by adding fresh sand to sand or recovered sand and mixing them can be used.
  • Such a refractory aggregate is generally used with a particle size of about 40 to 130, preferably about 50 to 110 in terms of AFS index.
  • the refractory aggregate is preferably spherical, and specifically, a refractory aggregate having a particle shape factor of 1.2 or less, more preferably 1.0 to 1.1 is desirable.
  • a fireproof aggregate with a particle shape factor of 1.2 or less the fluidity and filling properties during mold making are improved, and the number of contacts between aggregates increases, so that the same strength is expressed. It is possible to reduce the amount of binders and additives necessary for the treatment.
  • the particle size coefficient of the aggregate used here is generally adopted as one scale indicating the outer shape of the particle, and is also referred to as a particle shape index, and as the value approaches 1, This means approaching a sphere (true sphere).
  • a particle shape factor is represented by the value calculated using the surface area (sand surface area) of the aggregate measured by various well-known methods, for example, a sand surface area measuring device ( This means a value obtained by measuring the surface area of actual aggregate particles (granular sand) per gram using George Fischer) and dividing it by the theoretical surface area.
  • a theoretical surface area is a surface area when it is assumed that aggregate particles (sand particles) are all spherical.
  • a binder mainly composed of water glass is used as a binder for covering the fireproof aggregate as described above.
  • Water glass is a water-soluble silicate compound.
  • silicate compound include sodium silicate, potassium silicate, sodium metasilicate, potassium metasilicate, lithium silicate, and ammonium silicate.
  • sodium silicate (sodium silicate) is particularly advantageously used in the present invention.
  • various water-soluble binders such as thermosetting resins, saccharides, proteins, synthetic polymers, salts and inorganic polymers may be used in combination as long as water glass is used as a main component. Is possible.
  • the ratio of water glass in the whole binder is preferably 60% by mass or more, more preferably 80% by mass or more, and most preferably 90% by mass. That's it.
  • sodium silicate is usually classified and used as No. 1 to No. 5 depending on the molar ratio of SiO 2 / Na 2 O 2 .
  • sodium silicate No. 1 has a SiO 2 / Na 2 O molar ratio of 2.0 to 2.3
  • sodium silicate No. 2 is SiO 2 / Na 2 O 2 The molar ratio is 2.4 to 2.6
  • sodium silicate No. 3 has a SiO 2 / Na 2 O molar ratio of 2.8 to 3.3
  • sodium silicate No. 4 has a SiO 2 / Na 2 O molar ratio of 3.3 to 3.5
  • sodium silicate No. 5 has a SiO 2 / Na 2 O molar ratio. Is 3.6 to 3.8.
  • sodium silicate Nos. 1 to 3 are also defined in JIS-K-1408.
  • these various sodium silicates may be used alone or in combination, and the molar ratio of SiO 2 / Na 2 O may be adjusted by mixing. Is possible.
  • the sodium silicate constituting the water glass used as the binder generally has a SiO 2 / Na 2 O molar ratio of 1.9 or more, preferably Is preferably 2.0 or more, more preferably 2.1 or more, and sodium silicate corresponding to No. 1 and No. 2 in the above-mentioned classification of sodium silicate is particularly advantageously used.
  • Such sodium silicates No. 1 and No. 2 provide dry coated sand having stable and good characteristics even when the sodium silicate concentration in the water glass is wide.
  • the upper limit of the SiO 2 / Na 2 O molar ratio in such sodium silicate is appropriately selected according to the characteristics of the water glass in the form of an aqueous solution, but generally 3.5 or less, It is preferably 3.2 or less, more preferably 2.7 or less.
  • the molar ratio of SiO 2 / Na 2 O is smaller than 1.9, the viscosity of the water glass is lowered, and it becomes difficult to make the coated sand dry unless the water content is considerably reduced.
  • it exceeds 3.5 the solubility in water decreases, the adhesion area cannot be gained, and the strength of the mold finally obtained may decrease.
  • the water glass used in the present invention means a solution of a silicate compound in a state dissolved in water.
  • water is added to such a stock solution as purchased in the market. It is added and used in a diluted state.
  • the non-volatile content water glass component
  • solid content which corresponds to the above-described soluble silicate compound such as sodium silicate.
  • the higher the proportion of such solid content (nonvolatile content) the higher the concentration of the silicate compound in the water glass.
  • the solid content of the water glass used in the present invention corresponds to the amount excluding the amount of water in the stock solution when it is composed only of the stock solution, while the stock solution is converted into water.
  • the amount excluding the amount of water in the stock solution and the amount of water used for dilution corresponds to the solid content of the water glass used. It becomes.
  • the solid content in the water glass is set to an appropriate ratio depending on the type of the water glass component (soluble silicate compound), etc., but is preferably a ratio of 20 to 50% by mass. It is desirable to be contained in By making the water glass component corresponding to the solid content appropriately present in the aqueous solution, the water glass component can be uniformly and uniformly applied to the fire resistant aggregate during mixing (kneading) with the fire resistant aggregate. So that the target mold can be advantageously formed. If the concentration of the water glass component in the water glass is too low and the total amount of solids is less than 20% by mass, the heating temperature is increased or the heating time is increased for drying the coated sand. For this reason, problems such as energy loss are caused.
  • the ratio of the solid content in the water glass becomes too high, it becomes difficult to uniformly coat the surface of the refractory aggregate with the water glass component, which causes a problem in improving the properties of the target mold. Therefore, it is desirable to prepare water glass in the form of an aqueous solution so that the solid content is 50% by mass or less, and thus the water content is 50% by mass or more.
  • the water glass as described above is preferably in a ratio of 0.1 to 5.0 parts by mass in terms of solid content when considered as only non-volatile content with respect to 100 parts by mass of the refractory aggregate. It is desirable to use in a proportion of 0.1 to 2.5 parts by weight, and in particular, a proportion of 0.2 to 2.0 parts by weight is particularly advantageously employed to provide a predetermined coating on the surface of the refractory aggregate. A layer will be formed.
  • the measurement of solid content is implemented as follows. That is, 10 g of a sample was weighed and stored in an aluminum foil dish (length: 9 cm, width: 9 cm, height: 1.5 cm), placed on a heating plate maintained at 180 ⁇ 1 ° C., and left for 20 minutes.
  • Solid content (mass%) [mass after drying (g) / mass before drying (g)] ⁇ 100
  • the amount of water glass used is too small, it is difficult to form a coating layer on the surface of the refractory aggregate, and there is a possibility that solidification or curing of the coated sand at the time of mold making may not proceed sufficiently. is there.
  • a moisturizer is contained in a coating layer containing water glass that covers the surface of the refractory aggregate.
  • the moisturizing agent when the moisturizing agent is contained in the coating layer containing water glass, when the moisture is supplied to the coated sand of the present invention during the mold making, the wet state Will be maintained for a long time. For this reason, even if a long time elapses from the supply of moisture to the coated sand to the actual molding of the mold (filling into the mold, solidification or curing by heating), the wet state is maintained. As a result, the adhesiveness of the water glass is also advantageously maintained, so that the mold finally obtained exhibits excellent strength.
  • the wet state can be maintained for a long time, when forming a mold using the coated sand of the present invention, the amount of water added (use amount) can be minimized. It has excellent releasability from the mold of the molded mold, and also has the effect of improving the disintegration of the obtained mold. It can be enjoyed advantageously.
  • the amount of the humectant contained in the coating layer containing water glass is 0.1 to 20.0 parts by mass with respect to 100 parts by mass of the solid content of the water glass in the coating layer. Desirably, it is preferably 0.5 to 15.0 parts by mass, particularly preferably 0.75 to 12.5 parts by mass. If the amount of the moisturizing agent contained is too small, the above-mentioned effects may not be enjoyed advantageously. On the other hand, if the amount of the moisturizing agent is too large, blocking due to moisture absorption may occur. The improvement of the effect according to the amount used is not recognized, and it is not a good idea from the viewpoint of cost effectiveness.
  • humectants examples include polyhydric alcohols, water-soluble polymers, hydrocarbons, proteins, and inorganic compounds.
  • a polyhydric alcohol and a water-soluble polymer are particularly preferable from the viewpoints of cost and convenience because the wet state can be maintained for a long time.
  • polyhydric alcohols include ethylene glycol, diethylene glycol, triethylene glycol, polyethylene glycol, polypropylene glycol, dipropylene glycol, propylene glycol, butylene glycol, 1,2-butanediol, 1,2-pentanediol, , 5-pentanediol, 1,2-hexanediol, 2-ethyl-1,3-hexanediol, 1,6-hexanediol, 1,2-heptanediol, 1,2-octanediol, 1,2,6 -Hexanetriol, thioglycol, hexylene glycol, glycerin, trimethylolethane, trimethylolpropane and the like.
  • the water-soluble polymer compound particularly refers to a compound having 5 to 25 alcoholic hydroxyl groups per 1000 molecular weight.
  • water-soluble polymer compounds include vinyl alcohol polymers such as polyvinyl alcohol and various modified products thereof; celluloses such as alkyl cellulose, hydroxyalkyl cellulose, alkyl hydroxyalkyl cellulose, carboxymethyl cellulose, hydroxyethyl cellulose, and hydroxypropyl methyl cellulose. Derivatives; starch derivatives such as alkyl starch, carboxymethyl starch and oxidized starch; and water-absorbing polymers such as sodium polyacrylate.
  • hydrocarbons examples include aliphatic hydrocarbons, alicyclic hydrocarbons, aromatic hydrocarbons, petroleum ether, petroleum benzyl, tetralin, decalin, tertiary amylbenzene, dimethylnaphthalene and the like.
  • inorganic compounds include sodium chloride, sodium sulfate, calcium chloride, magnesium chloride, and silicate. These various humectants can be used alone or in admixture of two or more.
  • saccharides are also considered, and examples thereof include monosaccharides, oligosaccharides, polysaccharides such as dextrins, etc.
  • monosaccharides can be decomposed into simpler saccharides by hydrolysis. Saccharides that cannot be produced, preferably tricarbon sugar (monosaccharide having 3 carbon atoms) to decacarbon sugar (monosaccharide having 10 carbon atoms), more preferably hexose sugar (monocarbon having 6 carbon atoms) Sugars).
  • various conventionally known moisturizers include those that are water-soluble to those that are sparingly water-soluble.
  • the viscosity increases when poured into water at room temperature (25 ° C.).
  • a moisturizing agent with a low is advantageously used.
  • a water-soluble humectant an amount of humectant corresponding to 20% of the mass of water is added to water at room temperature, and the mixture is stirred for 1 hour.
  • a poorly water-soluble humectant exhibits an effect as a humectant when dispersed in water.
  • the humectant advantageously used in the present invention includes cellulose derivatives such as glycerin and hydroxypropylmethylcellulose, water-absorbing polymers such as sodium polyacrylate, vinyl alcohol polymers such as polyvinyl alcohol, and weight average molecular weight. 50,000 or more polyethylene glycol (polyethylene oxide) etc. can be mentioned.
  • the coating layer of the coated sand of the present invention contains spherical particles having an average particle diameter of 0.1 to 20.0 ⁇ m, preferably spherical particles having an average particle diameter of 0.5 to 10.0 ⁇ m. May be.
  • the content of such spherical particles is 0.1 to 500 parts by weight, preferably 0.3 to 300 parts by weight, more preferably 100 parts by weight of the solid content of water glass in the coating layer. Is 0.5 to 200 parts by mass, more preferably 0.75 to 100 parts by mass, and most preferably 1.0 to 50 parts by mass.
  • the average particle diameter of the spherical particles can be determined from the particle size distribution measured by a laser diffraction type particle size distribution measuring device or the like.
  • the spherical particles used in the present invention are not particularly limited as long as they have a spherical shape, and are not necessarily required to have a true spherical shape. Usually, those having a sphericity of 0.5 or more are preferably 0. Those of 0.7 or more, more preferably 0.9 or more, are advantageously used.
  • the sphericity is the average value of the aspect ratio (minor axis / major axis ratio) obtained from the projection shape of 10 single particles randomly selected in scanning electron microscope observation. I mean.
  • non-spherical particles since there are protrusions and depressions on the surface of non-spherical particles (non-spherical particles), for example, the non-spherical particles are refractory aggregate together with water glass that has become a solution by the supplied moisture.
  • non-slip action occurs due to the collision between the projections on the surface of the non-spherical particles and the refractory aggregate particles or other non-spherical particles, and water between the refractory aggregate particles The flow of glass and non-spherical particles is impeded. For this reason, when non-spherical particles are used in the present invention, there is a risk of reducing the filling properties and strength of the finally obtained mold.
  • the material constituting the spherical particles used in the present invention is not particularly limited, but is preferably an inorganic metal oxide.
  • particles composed of inorganic metal oxides particles composed of silicon dioxide, aluminum oxide, titanium oxide, etc. are advantageously used.
  • silicon dioxide particles are strongly alkaline water glass composed of silicon dioxide. It can react with silanol groups formed on the surface, and when water is evaporated, a strong bond is formed between silicon dioxide and solid water glass, which can improve the mold strength. ,preferable. Silicon dioxide has crystallinity and amorphousness, but amorphous is desirable.
  • Amorphous silicon dioxide includes precipitated silica, calcined silica produced in an electric arc or by flame hydrolysis, ZrSiO Examples include silica produced by pyrolysis of 4 , silicon dioxide produced by oxidation of metallic silicon with a gas containing oxygen, and quartz glass powder of spherical particles produced from crystalline quartz by melting and subsequent rapid cooling. . Of course, these can be used alone or in combination of two or more. In the present invention, silicon dioxide is treated as an inorganic metal oxide.
  • the coated sand of the present invention in addition to the above-described moisturizing agent and the like, various additives can be appropriately contained in the coating layer as necessary.
  • a surfactant can be exemplified as one of such additives.
  • a surfactant is contained in the coating layer of the coated sand of the present invention, the water permeability in the coated sand, in other words, the wettability of the coated sand with respect to water is effectively improved. Even when a small amount of moisture is supplied to the coated sand filled therein, the entire coated sand in the molding cavity is advantageously wetted and becomes wet. As described above, since the amount of moisture added to the coated sand can be suppressed to a small amount, the mold release property of the molded mold is further improved, and the obtained mold exhibits more excellent strength. It will be.
  • surfactants for example, cationic surfactants, anionic surfactants, amphoteric surfactants, nonionic surfactants, silicone surfactants and fluorine-based surfactants. Any surfactant or the like can be used as long as the object of the present invention is not impaired.
  • the silicone-based surfactant specifically indicates a surfactant having a siloxane structure as a nonpolar site, and the fluorine-based surfactant particularly indicates a surfactant having a perfluoroalkyl group.
  • the content of the surfactant in the present invention is desirably 0.1 to 20.0 parts by mass with respect to 100 parts by mass of the solid content of water glass in the coating layer, and more preferably 0.5 to 15 parts by mass. 0.0 parts by mass is preferable, and 0.75 to 12.5 parts by mass is particularly preferable. If the amount of the surfactant is too small, the above effects may not be enjoyed advantageously. On the other hand, if the amount of the surfactant is too large, an improvement in the effect according to the amount used is recognized. Depending on the surfactant, the water glass may not be solidified when it is dried, and may not be obtained even when trying to obtain a dry coated sand. Further, from the viewpoint of cost-effectiveness. It's not a good idea.
  • a moisture resistance improver may be contained in the coating layer. Inclusion of a moisture resistance improver in the coating layer can improve the moisture resistance of the final mold.
  • any agent can be used as long as it is conventionally used in the coated sand as long as it does not impair the effects of the present invention.
  • carbonates such as zinc carbonate, basic zinc carbonate, iron carbonate, manganese carbonate, copper carbonate, aluminum carbonate, barium carbonate, magnesium carbonate, calcium carbonate, lithium carbonate, potassium carbonate, sodium carbonate, tetraboric acid Sodium, potassium tetraborate, lithium tetraborate, ammonium tetraborate, calcium tetraborate, strontium tetraborate, silver tetraborate, sodium metaborate, potassium metaborate, lithium metaborate, ammonium metaborate, metaborate Calcium, silver metaborate, borate salts such as copper metaborate, lead metaborate, magnesium metaborate, sodium sulfate, potassium sulfate, lithium sulfate, magnesium sulfate, calcium sulfate, strontium sulfate, barium sulfate, titanium sulfate, aluminum sulfate, sulfuric acid Zinc, copper sulfate Sulfate S
  • basic zinc carbonate, sodium tetraborate, potassium metaborate, lithium sulfate, and lithium hydroxide can improve moisture resistance more advantageously.
  • the moisture resistance improvers including those described above can be used alone, and two or more kinds can be used in combination.
  • the amount of such moisture resistance improver used is preferably about 0.5 to 50 parts by mass with respect to 100 parts by mass of the solid content of water glass. Is more preferably 20 parts by mass, and particularly preferably 2-15 parts by mass. In order to advantageously enjoy the effect of adding the moisture resistance improver, it is desirable that the amount used is 0.5 parts by mass or more. On the other hand, if the amount added is too large, binding of water glass is inhibited, It is desirable that the amount be 50 parts by mass or less because there is a possibility of causing problems such as a decrease in the strength of the finally obtained mold.
  • a coupling agent that strengthens the bond between the refractory aggregate and water glass.
  • a silane coupling agent, a zircon coupling agent, a titanium coupling agent Etc. can be used.
  • waxes such as paraffin wax, synthetic polyethylene wax, and montanic acid wax; stearic acid amide, oleic acid amide, erucic acid amide, etc.
  • Fatty acid amides such as methylene bis stearic acid amide and ethylene bis stearic acid amide; stearic acid, stearyl alcohol; stearic acid metal salts such as lead stearate, zinc stearate, calcium stearate, magnesium stearate; stearin Acid monoglycerides, stearyl stearate, hydrogenated oils and the like can be used.
  • release agents paraffin, wax, light oil, machine oil, spindle oil, insulating oil, waste oil, vegetable oil, fatty acid ester, organic acid, fine graphite particles, mica, meteorite, fluorine release agent, silicone release agent An agent or the like can also be used.
  • Each of these other additives is generally 5% by mass or less, preferably 3% by mass or less with respect to the solid content of the water glass in the coated sand coating layer. It is contained in
  • water glass as a binder is generally used as needed with a moisturizer for a fireproof aggregate.
  • Additives are added, kneaded or mixed, and mixed uniformly to cover the surface of the refractory aggregate with water glass containing a moisturizing agent and the like.
  • a technique is employed in which a coating layer containing water glass and a moisturizing agent is formed on the surface of the refractory aggregate by evaporating the water. In such a technique, water vaporization of the coating layer needs to be performed quickly before the water glass solidifies or hardens, so that the water glass in the form of an aqueous solution is used against the refractory aggregate.
  • the refractory aggregate is preheated and water in the form of an aqueous solution is added.
  • a technique is adopted in which glass and a humectant are kneaded or mixed to be mixed.
  • the water in the water glass is very quickly heated by the heat of such refractory aggregate. This means that the moisture content of the resulting coated sand can be effectively reduced, and a dry powder having room temperature fluidity can be advantageously obtained.
  • the preheating temperature of the refractory aggregate is appropriately selected depending on the water content of the water glass and the blending amount thereof, but generally a temperature of about 100 to 160 ° C. is preferable. A temperature of about 100 to 140 ° C. is employed. If this preheating temperature is too low, it is not possible to effectively evaporate water, and it takes time to dry. Therefore, it is desirable to employ a temperature of 100 ° C. or higher. If it is too high, hardening of the water glass component will proceed while cooling of the resulting coated sand, and in addition, the formation of composite particles will proceed, so the function as the coated sand, especially the strength of the final mold obtained. This causes problems in physical properties.
  • the moisturizing agent contained in the coating layer containing water glass and other additives used as necessary, such as spherical particles and surfactants, were previously mixed with water glass. It may be added to the refractory aggregate in a state and kneaded, or it may be added separately from the water glass at the time of kneading and kneaded, and further, there will be a time difference between the addition of the water glass at the time of kneading. It may be provided and charged and kneaded.
  • the coating layer in the coated sand of the present invention is, for example, in a state where the water glass and the moisturizing agent are integrally integrated, or outward from the surface of the refractory aggregate. While the concentration of (nonvolatile content) gradually decreases or increases, the concentration of the humectant and the like gradually increases or decreases.
  • the timing of adding the water glass and the humectant to the refractory aggregate during kneading it is desirable to first add the humectant and knead, and then add the water glass (with a time difference). .
  • the concentration of water glass solids gradually increases from the surface of the refractory aggregate to the outside, while the concentration of the humectant gradually decreases. Occurrence of blocking is advantageously prevented since the amount of the humectant present in is suppressed to a small amount. Further, when the coated sand of the present invention is produced, the water glass as a binder can be used even if it is diluted with water in order to adjust the viscosity. It is also possible to add water glass and water separately during kneading or mixing with the material.
  • the dry coated sand having room temperature fluidity according to the present invention preferably has a moisture content of 5 with respect to the solid content of the water glass contained in the coating layer covering the surface of the refractory aggregate.
  • the following two methods can be exemplified as a method for forming a mold using the dry coated sand according to the present invention.
  • dry coated sand and water are kneaded at the molding site where the mold is manufactured to make the coated sand wet, and the wet coated While filling the sand into the mold cavity of the mold that gives the target mold, the mold is heated to a temperature of 90-200 ° C. until the filled coated sand is dried in the mold, Will be held.
  • the coated sand is filled into the mold cavity of the mold that gives the target mold, water vapor is blown, and the flow phase of the water vapor wets the filled phase of the coated sand, Thereafter, it is held in a mold heated to 90 to 200 ° C. until it is dried.
  • molds such as molds and wooden molds, which are filled with dry coated sand having room temperature fluidity, are preferably preliminarily kept warm by heating, thereby being wetted by water vapor.
  • the drying of the coated sand can proceed advantageously.
  • a temperature of about 90 to 200.degree. C., particularly about 100 to 140.degree. C. is desirable as the temperature for preheating. If the temperature is too high, it becomes difficult for steam to pass to the surface of the mold, while if the temperature is too low, it takes time to dry the molded mold.
  • the dry coated sand to be filled in such a mold is also preferably preheated.
  • the bending strength of the obtained mold can be increased more advantageously by filling the molding die with the coated sand heated to a temperature of 30 ° C. or higher.
  • the heating temperature of such coated sand is preferably about 30 to 100 ° C., and particularly, coated sand heated to a temperature of about 40 to 80 ° C. is advantageously used.
  • the step of adding water to the wet coated sand to make it wet simply puts the dry coated sand and a predetermined amount of water into an appropriate mixer and mixes them. Therefore, there is an advantage that it can be carried out by a very simple work and can be carried out very easily and easily even in a molding site where the working environment is bad. In addition, it is also possible to add another additive at the time of addition of water. Further, in the first method, instead of heating the mold, the coated sand is blown into the wet coated sand filled in the mold by blowing dry air, dry heated air, nitrogen gas, or the like. It is also possible to dry and solidify or harden the sand.
  • the temperature of the water vapor to be aerated is generally about 80 to 150 ° C., more preferably about 95 to 120 ° C.
  • a steam temperature around 100 ° C. is advantageously employed.
  • a gauge pressure value of about 0.01 to 0.3 MPa, more preferably about 0.01 to 0.1 MPa is advantageously employed.
  • an aeration time of about 2 seconds to 60 seconds is generally employed.
  • a curing agent may be added in the mold as an additive for promoting the hardening of the water glass during holding of the mold. It is possible to further promote the solidification by neutralizing the binder (water glass) with a curing agent. It should be noted that the curing agent may be vented at any timing as long as it is being held in the mold, and there is no problem even if it is performed simultaneously with the vaporization of water vapor or the ventilation of dry air or the like.
  • Curing agents include carbon dioxide (carbonated water), sulfuric acid, hydrochloric acid, nitric acid, phosphoric acid, oxalic acid, carboxylic acid, paratoluenesulfonic acid and other organic acids, methyl formate, ethyl formate, propyl formate, ⁇ -butyrolactone, Examples include ⁇ -propionlactone, ethylene glycol diacetate, diethylene glycol diacetate, glycerol diacetate, triacetin, propylene carbonate, and other monovalent alcohols such as methanol, ethanol, butanol, hexanol, and octanol. .
  • curing agents can be used alone, or two or more of them can be mixed and used.
  • these hardeners are good to ventilate the gas mold or mist while holding the mold, into the mold, and when wetted by adding water to the dry coated sand, A curing agent may be added together with water.
  • a predetermined amount of water is added to each CS manufactured according to the method shown below to make it wet (wet condition), and the wet CS immediately after being wetted is a constant temperature of 25 ° C. ⁇ humidity of 30%.
  • the breaking load of each test piece obtained is measured using a measuring instrument (manufactured by Takachiho Seiki Co., Ltd .: Digital foundry sand strength tester). Then, using this measured breaking load, the bending strength is calculated by the following equation (5).
  • a molten metal injection port 2 formed in advance at room temperature self-hardening sand and a core base fixing portion 4 at a lower portion (this portion is a discharge port for a waste core from a casting).
  • this portion is a discharge port for a waste core from a casting.
  • the half-cracked hollow main mold 6 (cavity diameter: 6 cm, height: 6 cm) having circular baseless cores 10 (diameter: 5 cm, high 5 cm) is bonded and fixed by the skirting board fixing portion 4, and the opposite hollow main mold 6 is further bonded and fixed to produce a sand mold 12 for casting test.
  • molten aluminum alloy (temperature: 710 ⁇ 5 ° C.) is poured from the molten metal inlet 2 of the casting test sand mold 12 and solidified, and then the main mold 6 is broken to form a circular waste as shown in FIG.
  • an impact is applied to the obtained casting 16 at a pressure of 0.2 MPa for 3 seconds at a time by an air hammer and discharged from the discharge port 14. The impact by the air hammer was repeated until 100% of the core sand was discharged, and the number of times was indicated.
  • the water glass is added to the lunamos # 80 100 1.21 parts (solid component: 0.50 parts) with respect to parts, and glycerin as a moisturizer added at a ratio of 0.02 parts (4 parts with respect to 100 parts of water glass solids) Knead for 3 minutes to evaporate the water, stir and mix until the lump of sand collapses, and then add 0.01 part of calcium stearate (2 parts per 100 parts of water glass solids) The mixture was then stirred and mixed, and then taken out to obtain dry coated sand: CS1 having room temperature fluidity. When the moisture content of CS1 after such kneading was calculated, it was an amount corresponding to 40% by mass of the solid content of water glass in the coating layer.
  • dry CS 5- As a moisturizer, instead of glycerin, a commercially available polyvinyl alcohol: PVA220 (product name: Kuraray Co., Ltd.) was used, and this was 0.04 parts (water) with respect to 100 parts of the fire-resistant aggregate (Lunamos # 80).
  • a dry CS5 having room temperature fluidity was obtained according to the same procedure as in Production Example 1 except that it was added at a ratio of 8 parts to 100 parts of the solid content of the glass. When the moisture content of the obtained CS5 was calculated, it was an amount corresponding to 40% by mass of the solid content of water glass in the coating layer.
  • this inventor used the micro track particle size distribution measuring apparatus (MT3200II: product name) by Nikkiso Co., Ltd., and calculated the particle diameter of 50% of integrated value from an average particle diameter from particle size distribution. When measured as (D 50 ), it was confirmed that the error between the measured value and the published value was within 10%.
  • M3200II micro track particle size distribution measuring apparatus
  • Examples 1 to 10, Comparative Examples 1 to 3)- CS1 to 13 obtained in the above dry CS production examples 1 to 13 are put into a Shinagawa universal agitator (5DM-r type), and water is added to the refractory aggregate (Lunamos #) constituting each CS. 2) was added to 100 parts of 80) and stirred for 1 minute.
  • the wet CS thus obtained is placed in a blow tank, filled in a mold heated to 150 ° C. by blowing at a gauge pressure of 0.3 MPa, and then held in the mold for 1 minute and 30 seconds. Then, the molds used as test pieces [1.0 cm ⁇ 1.0 cm ⁇ 6.0 cm] were respectively produced by curing CS1 to CS13.
  • the dry coated sand according to the present invention is excellent in the mold release property of the molded mold from the mold, and further, the obtained mold has a good disintegration property.

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  • Chemical & Material Sciences (AREA)
  • Materials Engineering (AREA)
  • Mechanical Engineering (AREA)
  • Mold Materials And Core Materials (AREA)

Abstract

Le but de la présente invention est de produire un sable enduit à sec ayant une fluidité à température normale pouvant maintenir un état humide sur une longue période de temps lorsqu'il humidifié par ajout d'humidité lors de la formation d'un moule, le moule final obtenu présentant une meilleure résistance. L'invention concerne du sable enrobé à sec formé par la surface d'un agrégat réfractaire enduit d'une couche d'enduit qui comprend du verre soluble en tant qu'agent d'agglomération, et ayant une fluidité à température normale, le sable enduit étant constitué par l'inclusion d'un agent de retenue d'humidité dans cette couche d'enduit.
PCT/JP2017/042007 2016-11-22 2017-11-22 Sable enduit, son procédé de fabrication et procédé de fabrication pour moule l'utilisant WO2018097179A1 (fr)

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Cited By (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN111687374A (zh) * 2020-07-07 2020-09-22 曲阜市铸造材料厂 一种水玻璃再生砂及其制备方法
CN112548034A (zh) * 2021-01-07 2021-03-26 山东理工大学 一种铸造砂型、工艺及砂型含水率控制系统
JP2021137876A (ja) * 2021-04-28 2021-09-16 大阪硅曹株式会社 無機鋳型および中子の造型方法
CN114929410A (zh) * 2020-01-07 2022-08-19 花王株式会社 无机覆膜砂
JP7418279B2 (ja) 2020-04-30 2024-01-19 旭有機材株式会社 鋳型の製造方法
JP7467221B2 (ja) 2020-04-30 2024-04-15 旭有機材株式会社 鋳型の造型方法

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* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN113510217B (zh) * 2021-09-15 2021-12-24 中车戚墅堰机车车辆工艺研究所有限公司 一种温芯盒成型的无机干态覆膜砂及其制芯方法
CN114309452B (zh) * 2021-11-15 2023-07-25 北京仁创砂业铸造材料有限公司 覆膜砂添加剂、覆膜砂及其制备方法
CN114799038B (zh) * 2022-05-26 2023-11-10 南阳仁创砂业科技有限公司 一种易溃散覆膜砂及制备方法

Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2368322A (en) * 1940-02-20 1945-01-30 Passelecq Georges Core making process
JPS486691B1 (fr) * 1968-12-25 1976-02-28
JP2012076113A (ja) * 2010-10-01 2012-04-19 Lignyte Co Ltd 粘結剤コーテッド耐火物、鋳型、鋳型の製造方法
JP2013094834A (ja) * 2011-11-02 2013-05-20 Tsuchiyoshi Industry Co Ltd 鋳型材料及び鋳型並びに鋳型の製造方法
WO2015194550A1 (fr) * 2014-06-20 2015-12-23 旭有機材工業株式会社 Procédé de fabrication de moule et moule

Family Cites Families (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP2163328A1 (fr) * 2008-09-05 2010-03-17 Minelco GmbH Sable de noyau ou de moule revêtu par et/ou mélangés avec des silicates de potassium ayant une teneur en eau comprise entre environ 0,25 poids -% jusqu'à environ 0,9 poids -%
EP2937160A4 (fr) * 2012-12-19 2016-09-07 Asahi Yukizai Corp Sable enrobé, procédé de fabrication de celui-ci et procédé de fabrication d'un moule

Patent Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2368322A (en) * 1940-02-20 1945-01-30 Passelecq Georges Core making process
JPS486691B1 (fr) * 1968-12-25 1976-02-28
JP2012076113A (ja) * 2010-10-01 2012-04-19 Lignyte Co Ltd 粘結剤コーテッド耐火物、鋳型、鋳型の製造方法
JP2013094834A (ja) * 2011-11-02 2013-05-20 Tsuchiyoshi Industry Co Ltd 鋳型材料及び鋳型並びに鋳型の製造方法
WO2015194550A1 (fr) * 2014-06-20 2015-12-23 旭有機材工業株式会社 Procédé de fabrication de moule et moule

Cited By (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN114929410A (zh) * 2020-01-07 2022-08-19 花王株式会社 无机覆膜砂
JP7418279B2 (ja) 2020-04-30 2024-01-19 旭有機材株式会社 鋳型の製造方法
JP7467221B2 (ja) 2020-04-30 2024-04-15 旭有機材株式会社 鋳型の造型方法
CN111687374A (zh) * 2020-07-07 2020-09-22 曲阜市铸造材料厂 一种水玻璃再生砂及其制备方法
CN112548034A (zh) * 2021-01-07 2021-03-26 山东理工大学 一种铸造砂型、工艺及砂型含水率控制系统
JP2021137876A (ja) * 2021-04-28 2021-09-16 大阪硅曹株式会社 無機鋳型および中子の造型方法

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