JP6501147B2 - Method of manufacturing mold - Google Patents

Description

  The present invention relates to a method of manufacturing a mold using a binder coated refractory.

  Conventionally, there are various methods for manufacturing a mold, and one of them is a shell mold method. The shell mold method is obtained by bonding and molding a refractory aggregate for a mold such as silica sand with a binder, and has excellent properties such as obtaining a mold with good dimensional accuracy. It is widely used from

  A thermosetting resin such as a phenol resin is generally used as a caking agent for this shell mold, and the fireproof aggregate and the thermosetting resin are mixed to form a thermosetting resin on the surface of the fireproof aggregate. A coated binder coated refractory (abbreviated as RCS) is prepared, and this binder coated refractory is filled in a heated mold to melt and cure the thermosetting resin of the binder. By which the mold is made. The binder-coated refractories itself is a granular material which is smooth and has a good flowability, so that it has a good filling property into a mold, can be pneumatically transported, and has a good handling.

  When molding a mold using such a binder coated refractory, a binder coated refractory is filled in a mold heated to a high temperature of 250 to 350 ° C., and a conductive heat transfer from the high temperature mold is performed. In general, it is common practice to heat the binder coated refractory by heating, but when the binder phenolic resin is heated at high temperature, ammonia gas etc. is generated along with its rapid reaction, There is a problem of causing deterioration of the environment.

  Therefore, after the mold is filled with a binder-coated refractory, water vapor is blown into the mold, and the binder-coated refractory in the mold is heated by the latent heat of evaporation of water vapor or sensible heat to make the mold A method of manufacturing has been proposed (see, for example, Patent Document 1).

  Thus, when steam is blown into the mold to heat the binder-coated refractory, the steam filled in the mold can heat the entire binder-coated refractory in the mold instantaneously. It is possible to stably mold the mold in a short time without the need to heat the mold to a high temperature, and prevent it from being absorbed into water vapor and released into the atmosphere even if ammonia gas is generated It can be done.

  However, when casting a molten metal by pouring it into a mold that has been molded in this way, the phenolic resin of the caking agent is decomposed by the action of the high temperature of the molten metal and, for example, phenol, xylenol, toluene, benzene, methane, etc. are released. There is a problem of deteriorating the working environment due to This problem can not be avoided as long as a thermosetting resin such as a phenol resin is used as a caking agent for the caking agent coated refractory.

  Furthermore, since the phenol resin has high heat resistance and a large amount of residual carbon, it is difficult to collapse the mold by the heat of the molten metal when the molten metal is injected into the mold and the cast is cast, and the cast is removed from the mold In addition, there is also a problem that it is necessary to apply an impact to the mold or to heat the resin for a long time at high temperature to decompose the phenol resin, which requires time and effort for demolding.

  Therefore, the applicant has proposed using a saccharide as a caking agent of a caking agent coated refractory (see, for example, Patent Document 2). That is, when a caking agent coated refractory coated with a solid coating layer containing saccharides as a caking agent is used and the caking agent coated refractory is filled in a forming die, water vapor is blown into the forming die Since the condensed water of water vapor is supplied to the binder coated refractory in the mold, the moisture imparts tackiness to the saccharide. Subsequently, the caking agent can be solidified by heating the caking agent-coated refractory in a forming die, and a mold having a refractory aggregate bonded thereto is formed by molding the solidified saccharide caking agent. It is something that can be done.

  When molten metal is poured into a mold containing such saccharides as a caking agent for casting, the saccharides, when thermally decomposed, release carbon dioxide gas and water, and release toxic gases. There is no risk of worsening the working environment because there is no Also, saccharides are easily thermally decomposed, and it is possible to obtain a disintegratable mold which is easily disintegrated by the heat of molten metal.

JP, 2000-61583, A Japanese Patent Publication No. 2011-030795

  As described above, molds using saccharides as a caking agent do not release toxic gas at the time of casting and have good disintegration properties, but have problems in mold strength and heat resistance. Met.

  That is, when steam is blown into a mold filled with a binder-coated refractory, water is supplied as condensed water to saccharides on the surface of the binder-coated refractory, and the moisture imparts tackiness to the saccharides by the moisture . Then, for example, the water in the mold is evaporated and the water is removed from the saccharide by heating with steam that is subsequently blown, and the sugar is dried and solidified from the sticky state containing the water, and this drying is A mold can be formed by bonding refractory aggregate with solidified sugar. Therefore, the refractory aggregate is only kept in a bonded state by the dried and solidified saccharides, so there is a problem that the strength and heat resistance of the mold are insufficient, and sometimes the mold may be broken when pouring the molten metal into the mold. was there.

  In addition, molds that use saccharides as a caking agent do not release toxic gases during casting, but a large amount of carbon dioxide gas and water are generated as thermal decomposition gases, so gas defects tend to occur in castings during casting, and yield Also had problems.

  The present invention has been made in view of the above points, and it is an object of the present invention to use a saccharide as a caking agent to produce a mold having high strength and heat resistance and capable of reducing the amount of gas generation in casting. It is

  In the method for producing a mold according to the present invention, a binder coated refractory 1 formed by coating a solid coating layer containing saccharides as a binder on the surface of the refractory aggregate is filled in the mold 2 A molded article in which the binder of the coating layer is solidified or cured by blowing steam into the mold 2 to heat the binder coated refractory 1, thereby forming a refractory aggregate bonded with the binder. After molding 3 in the molding die 2 and taking out the molding 3 from the molding die 2, the molding 3 is heat-treated.

  By using the caking agent coated refractory 1 formed by covering a solid coating layer containing saccharides as a caking agent as described above, it is formed by bonding a refractory aggregate as a caking agent with saccharides. Molds can be produced, sugars release carbon dioxide and water when thermally decomposed, and do not release toxic gases, and there is no such thing as polluting the environment, In addition, saccharides are easily thermally decomposed, so that a mold having good disintegration ability can be obtained.

  Then, water vapor is blown into the mold 2 filled with the binder coated refractory 1 to solidify or cure the binder, thereby forming the molded article 3 in which the refractory aggregate is bonded with the binder. When using this molded product 3 molded as saccharides as a caking agent as it is for molding inside as it is, the strength and heat resistance are insufficient, but this molded product 3 is taken out from the mold 2 and molded Heat treatment of product 3 increases the bond strength of the fireproof aggregate with saccharides and also improves the heat resistance of saccharides, because it is thought that water is generated from the molecules of saccharides and evaporates and condenses by heat treatment. It is possible to obtain a high-quality template, and by removing water from the saccharide molecule, the amount of decomposition gas generated at the time of casting decreases.

Further, the present invention is characterized in that the heat treatment of the molded product is carried out at a temperature of 100 to 350 ° C.
It is

  By setting the heat treatment temperature of the molding 3 in this range, the bonding strength with saccharides can be sufficiently increased.

  The present invention is also characterized in that the heat treatment of the molded product is performed for 10 to 200 minutes.

  By setting the time of the heat treatment of the molding 3 in this range, the bonding strength with saccharides can be sufficiently enhanced.

  Further, the present invention is characterized in that the molding 3 taken out of the molding die 2 is heat-treated in the heat treatment container 4.

  By using the heat treatment container 4 in which the temperature setting is easy, the molding 3 can be heat-treated at any temperature as required.

  Further, the present invention imparts adhesiveness to saccharides of the caking agent by blowing steam into the forming die 2 filled with the binder coated refractory 1 and supplying condensed water of the steam into the forming die 2, Subsequently, the binder coated refractory 1 is heated by the latent heat of condensation of the water vapor blown into the mold 2 and the sensible heat to solidify or harden the binder.

  When steam is blown into the forming mold 2, the steam comes into contact with the binder coated refractory 1 and heat is taken away, and the condensed water generated is supplied to the binder and the saccharide in the solid state is The condensed water can be moistened to give tackiness, and the fireproof aggregate can be bonded by this tackiness of saccharides, and then the latent heat of condensation of water vapor or sensible heat evaporates the water supplied to the binder and caking. The agent can be solidified or cured, and molding in the mold 2 can be efficiently performed.

  Further, the present invention is characterized in that heating of the binder coated refractory 1 in the mold 2 is performed by the steam injected into the mold 2 and the heating gas blown into the mold 2 subsequently to the steam. It is said that.

  By blowing steam into the mold 2 filled with the binder-coated refractory 1, the temperature of the binder-coated refractory 1 can be rapidly raised to around 100 ° C. by the latent heat of condensation of steam and sensible heat. Then, by blowing a heated gas into the mold 2, the condensed water can be quickly evaporated with this gas with little water content, and can be raised to a temperature of 100 ° C. or more in a short time. It is possible to increase the speed of raising the temperature in the mold 2 above the temperature at which the caking agent of the cinder coated refractory 1 solidifies or hardens, and the molding in the mold 2 It can be done efficiently.

  As the heating gas, heated air or a mixed gas of steam and air can be used.

  Furthermore, in the present invention, superheated steam can also be used as steam, in addition to saturated steam.

  In the present invention, the coating layer of the binder coated refractory 1 contains a carboxylic acid.

  The saccharide can be polymerized by the carboxylic acid, and the bond strength with the saccharide can be further enhanced to further improve the strength and heat resistance of the template.

  Further, in the present invention, the coating layer of the binder coated refractory 1 is characterized in that a thermosetting resin is contained in addition to the saccharide as the binder.

  The thermosetting resin can reinforce the bonding strength of the fireproof aggregate, and can further improve the strength and heat resistance of the mold. As this thermosetting resin, a phenol resin is preferable.

  At this time, the content of the thermosetting resin in the binder is preferably 80% by mass or less.

  Further, according to the present invention, the caking agent-coated refractory 1 is filled in the mold 2 and water is supplied into the mold 2 to impart tackiness to the saccharides of the caking agent, and subsequently, in the mold. Superheated steam is blown in, and the binder coated refractory 1 is heated by condensation latent heat of the superheated steam and sensible heat to solidify or harden the binder.

  Thus, by supplying water into the mold 2 first to moisten the caking agent, it is possible to make the saccharides tacky and to bond the refractory aggregate by the tackiness of the saccharides, and then it is dried. By blowing in superheated steam which is steam, it is possible to evaporate the water in the mold 2 efficiently, and to raise the temperature of the binder coated refractory 1 efficiently to solidify or harden the binder. It is possible to perform molding in the mold 2 efficiently.

  In the present invention, the caking agent-coated refractory 1 is filled in a forming die 2 and saturated steam is blown into the forming die 2 to supply condensed water of the steam to the caking agent to impart adhesiveness to the saccharides. Then, superheated steam is blown into the mold 2 and the binder coated refractory 1 is heated by the latent heat of condensation of the superheated steam and sensible heat to solidify or cure the binder. It is.

  Thus, by blowing saturated steam into the mold 2 first, the condensation water of this saturated steam having a large amount of water imparts adhesiveness to the saccharide of the caking agent, and the refractory aggregate is bonded by the adhesive force of the saccharide Next, by blowing superheated steam, which is dry steam, into the mold 2, the water in the mold 2 can be efficiently evaporated, and the binder coated refractory 1 is efficiently The temperature can be raised to solidify or cure the binder, and molding in the mold 2 can be efficiently performed.

  According to the present invention, by using caking agent coated refractory 1 formed by covering a solid coating layer containing saccharides as a caking agent, a refractory aggregate is bonded using saccharides as a caking agent. The mold can be produced, and the saccharides release only carbon dioxide gas and water when thermally decomposed, and do not release toxic gases, and there is no more to pollute the environment, and The saccharides are those which are easily thermolyzed and from which molds having good disintegration ability can be obtained. Then, water vapor is blown into the mold 2 filled with the binder coated refractory 1 to solidify or cure the binder, thereby forming the molded article 3 in which the refractory aggregate is bonded with the binder. When using this molded product 3 molded as saccharides as a caking agent as it is for molding inside as it is, the strength and heat resistance are insufficient, but this molded product 3 is taken out from the mold 2 and molded By performing heat treatment at a temperature higher than the heating temperature in the mold 2, the bonding strength of the refractory aggregate with saccharides is enhanced and the heat resistance of the saccharides is improved, and a mold having high strength and heat resistance can be obtained. Furthermore, the removal of water from the saccharide molecules reduces the amount of decomposition gas generated during casting.

The mold of the steam heating system used by an example of an embodiment of the present invention is shown. BRIEF DESCRIPTION OF THE DRAWINGS The heat processing container used by an example of embodiment of this invention is shown. It is a graph which shows the test result of the heat resistance of saccharides.

  Hereinafter, embodiments of the present invention will be described.

  The binder coated refractory 1 used in the present invention is formed by coating the surface of the particles of the fireproof aggregate with a solid coating layer containing a binder.

  Examples of the fireproof aggregate include, but are not limited to, silica sand, mountain sand, alumina sand, olivine sand, chromite sand, zircon sand, mullite sand, others, artificial sand and the like, These can be used alone or in combination of two or more of them. Incidentally, as artificial sand, artificially produced sand containing calcia, magnesia, alumina and the like can be exemplified, and artificially produced sand can be exemplified by crushing stones and rocks. That is, artificial sand may be generally used artificially produced sand.

  In addition, as saccharides, monosaccharides, oligosaccharides and polysaccharides can be used, and among various monosaccharides, oligosaccharides and polysaccharides, one type is selected and used alone or plural types are selected and used in combination It can also be done.

  Examples of monosaccharides used in the present invention include, but are not limited to, glucose (glucose), fructose (fructose), galactose and the like.

  Examples of oligosaccharides include disaccharides such as maltose (malt sugar), sucrose (sucrose), lactose (lactose), cellobiose and the like.

  Furthermore, as polysaccharides, there are starch sugar, dextrin, xanthan gum, curdlan, pullulan, cycloamylose, chitin, cellulose, starch, etc. From these, one type can be selected and used, and plural types can be used in combination. Here, examples of starch may include finished starch and modified starch. Specifically, raw starches such as potato starch, corn starch, high amylose, sweet potato starch, tapioca starch, sago starch, rice starch, amaranth starch, and their processed starches (soy roasted dextrin, enzyme-modified dextrin, acid-treated starch, Oxidized starch, dialdehyded starch, etherified starch (carboxymethyl starch, hydroxyalkyl starch, cationic starch, methylolated starch etc.), esterified starch (acetic acid starch, phosphoric acid starch, succinic acid starch, octenyl succinic acid starch, maleic acid starch Starch, higher fatty acid esterified starch, etc.), crosslinked starch, kraftized starch, moist heat-treated starch, etc. Among them, roasted dextrin, Containing modified dextrin, acid-treated starches, those low molecular weight as oxidized starch, and low viscosity, such as cross-linked starch starches are preferred.

  In addition, flour of cereal seeds containing sugars can also be used as a caking agent. Examples of the powder of seeds of cereals containing saccharides include wheat flour, rice flour, corn flour and the like.

  The coating layer of the binder coated refractory 1 may contain a saccharide, in particular, a carboxylic acid which causes a polysaccharide to undergo a polymerization reaction. As the carboxylic acid, a monovalent carboxylic acid or a divalent or higher polyvalent carboxylic acid can be used. For example, benzoic acid, salicylic acid, anthranilic acid and the like can be mentioned as a monovalent carboxylic acid, and polyvalent carboxylic acids such as oxalic acid, maleic acid, succinic acid, citric acid, fumaric acid, malic acid, tartaric acid And isophthalic acid, itaconic acid, butanetetradicarboxylic acid, methyl vinyl ether-maleic anhydride copolymer and the like. A monovalent carboxylic acid mainly acts as a reaction accelerator (curing accelerator, curing catalyst), and a polyvalent carboxylic acid mainly acts as a crosslinking agent (curing agent), and can cause sugars to polymerize. is there. They can be polymerized by polymerizing saccharides by the action of carboxylic acid, and in some cases, they can be cured. These carboxylic acids may be used alone or in combination of two or more.

  Although the compounding quantity of carboxylic acid changes with kinds of saccharides etc. and it is not specifically limited, It is preferable to set to the range used as 1-40 mass parts of carboxylic acids with respect to 100 mass parts of saccharides. The range of 1 to 30 parts by mass is particularly preferable. If the amount of the carboxylic acid is too small, it is difficult to cause the saccharide to undergo a polymerization reaction to a sufficient molecular weight. Moreover, even if it contains more carboxylic acid, the effect of polymerizing saccharides is not improved, so there is a possibility that it may be economically disadvantageous. Incidentally, it is preferable to mix the carboxylic acid with the saccharide in a state of being previously dissolved in water, in order to exert the effect as a curing agent highly.

  In the present invention, saccharides are used as the caking agent contained in the coating layer of the caking agent-coated refractory 1. However, a thermosetting resin is used in combination with the saccharide as the caking agent, and the coating layer is used. You may make it contain. By using a thermosetting resin in combination as a caking agent, the bonding strength of the refractory aggregate with the caking agent can be increased, and the strength and heat resistance of the mold are improved as compared to the case of using a saccharide alone as a caking agent. It is something that can be done. In particular, since the effect of improving the heat resistance of the mold is high, it is suitable for casting using a high-temperature molten metal.

  The content of the thermosetting resin in the coating layer is preferably set to 80% by mass or less, more preferably 50% by mass or less, based on the total amount of the saccharide and the thermosetting resin. When the content of the thermosetting resin is more than this, the effect of using a saccharide as a caking agent becomes insufficient.

  Although this thermosetting resin used together with saccharides as a caking agent is not particularly limited, it is possible to use resol type or novolac type phenol resin. The resol type phenolic resin and the novolac type phenolic resin may be used alone or in combination. Moreover, what made sugars and phenols react beforehand can also be used. The state before coating the refractory aggregate with a thermosetting resin as a binder may be either liquid or solid.

  The coating layer of the binder coated refractory 1 may contain a lubricant in the coating layer in order to improve the flowability of the binder coated refractory. As lubricants, aliphatic hydrocarbon lubricants such as paraffin wax and carnauba wax, higher aliphatic alcohols, aliphatic amide lubricants such as ethylenebisstearate amide and stearic acid amide, metallic soap lubricants, fatty acid ester lubricants Composite lubricants and the like can be used, among which metal soap lubricants are preferred. As the metal soap-based lubricant, calcium stearate, barium stearate, zinc stearate, aluminum stearate, magnesium stearate or the like, or a combination of two or more of these can be used.

  Then, the refractory aggregate is obtained by blending and mixing saccharides, thermosetting resin such as carboxylic acid and phenolic resin, reaction products of saccharides and phenols, lubricants, etc. with particles of the refractory aggregate, if necessary. The coating layer containing a binder containing a saccharide as a main component can be coated on the surface of the binder to obtain a binder-coated refractory 1 used in the present invention.

  The amount of the coating layer to be coated on the fireproof aggregate differs depending on the components, applications, etc., and can not be generally defined, but 0.5 to 5.0 parts by mass of the binder and the lubricant are based on 100 parts by mass of the fireproof aggregate In general, it is preferable to set so that the solid content is in the range of 0.02 to 0.15 parts by mass. When the binder exceeds 5.0 parts by mass with respect to 100 parts by mass of the refractory aggregate, it becomes difficult to knead the refractory aggregate and the binder. When the amount of the binder is less than 0.5 parts by mass with respect to 100 parts by mass of the fireproof aggregate, it becomes difficult to maintain the strength of the mold.

  As a method of coating the coating layer on the surface of the refractory aggregate to prepare the binder coated refractory 1, there are a hot coating method, a cold coating method, a semi-hot coating method, a powder solvent method and the like.

  In the hot coating method, a solid caking agent is added to and mixed with the fireproof aggregate heated to 110 to 180 ° C., and the caking agent melted by melting the solid caking agent by heating with the fireproof aggregate. The surface of the refractory aggregate is wetted and coated, and then the mixture is cooled while being held to obtain a granular, free-flowing, caking agent-coated refractory. Alternatively, a refractory aggregate heated to 110 to 180 ° C. is mixed and coated with a caking agent dissolved or dispersed in a solvent such as water, and the solvent is volatilized to obtain a caking agent coated refractory It is.

  In the cold coating method, a binder is dispersed or dissolved in a solvent such as water or methanol to form a liquid, which is added to particles of the fireproof aggregate and mixed, and the binder is coated by volatilizing the solvent. It is a method of obtaining a refractory.

  In the semi-hot coating method, a caking agent dispersed or dissolved in the above-mentioned solvent is added to particles of the fireproof aggregate heated to 50 to 90 ° C., mixed, and the solvent is volatilized to evaporate the solvent. How to get

  In the powder solvent method, a solid caking agent is crushed, this crushed caking agent is added to the particles of the fireproof aggregate, a solvent such as water or methanol is further added, and this is mixed to evaporate the solvent. Is a method of obtaining a binder coated refractory.

  In any of the above methods, the surface of the refractory aggregate can be coated with a solid coating layer at normal temperature (30 ° C.), and granular, free-flowing caking agent coated refractories can be obtained. The hot coat method is preferred in view of workability and the like. In addition, when mixing the binder with the refractory aggregate as described above, various coupling agents such as a curing agent, and a silane coupling agent for making the refractory aggregate and the binder be compatible, if necessary Also, carbonaceous materials such as graphite can be blended.

  When saccharides and thermosetting resin are used in combination as a caking agent, a method of forming a coating layer in which saccharides and thermosetting resin are mixed by simultaneously coating saccharides and thermosetting resin on a fireproof aggregate, fireproof bone There is a method of forming a two-layer coating layer by coating a surface of a material with a thermosetting resin and then coating a saccharide, and any method may be used.

  Next, a method for producing a mold using the binder coated refractory 1 prepared as described above will be described. First, the cinder coated refractory 1 is filled in the mold 2, steam is blown into the mold 2, and the cinder coated refractory 1 is heated by the latent heat of condensation of steam and the sensible heat, A molding 3 in which the refractory aggregate is bonded with a binder is molded in a mold 2.

  That is, when steam is blown into the mold 2 filled with the binder coated refractory 1, the steam comes into contact with the binder coated refractory 1 first to take heat and produce condensed water. Then, the condensed water acts on the caking agent of the coating layer of the caking agent coated refractory 1 so that the saccharide in the solid state in the caking agent absorbs this condensed water and swells to gelatinize, thereby forming a caking agent. Become wet and tacky, the refractory aggregate of binder coated refractory 1 is bonded with this tacky of sugars. If steam is continuously blown into the mold 2, the binder coated refractory 1 is heated by the latent heat of condensation of steam which is subsequently blown into the mold 2 and sensible heat, and the moisture acting on the binder is evaporated and dried. It is possible to solidify or cure the saccharide of the binder. In this way, the molded product 3 bonded with the solid caking agent obtained by solidifying or curing the refractory aggregate of the binder coated refractory 1 can be molded in the mold 2.

  As described above, when the caking agent in the coating layer of the caking agent-coated refractory 1 is heated by steam and formed, the saccharide contained as the caking agent is toxic gas when heated to solidify or cure. It does not occur in large quantities, and can be molded without polluting the environment.

  Here, although it is possible to use the molded product 3 obtained in this way as a mold as it is, since this molded product 3 is one obtained by molding a saccharide as a binder, it can be used as a mold Is often lacking in strength and heat resistance. Therefore, in the present invention, the molded product 3 is taken out from the mold 2, the molded product 3 is subjected to heat treatment, and the molded product 3 after the heat treatment is used as a mold.

  The temperature of the heat treatment is preferably 100 ° C. or more, more preferably 150 ° C. or more. If the temperature of the heat treatment is lower than this, the effect of the heat treatment of the molded product 3 can not be obtained sufficiently. Conversely, if the temperature of the heat treatment is too high, the saccharides may be thermally decomposed, so the temperature is preferably 350 ° C. or less, more preferably 300 ° C. or less, and particularly preferably 240 ° C. or less. Moreover, although the time of heat processing changes with sizes of the molding 3 shape | molded as a casting_mold | template, it is preferable that it is 10 minutes or more, and it is more preferable that it is 30 minutes or more. If the heat treatment time is shorter than this, the effect of the heat treatment of the molded product 3 can not be obtained sufficiently. Conversely, if the heat treatment time is too long, the saccharides may be degraded particularly when the heat treatment temperature is high. Therefore, the heat treatment time is preferably 200 minutes or less, and more preferably 80 minutes or less.

  When the molded product is heat-treated in this way, the molecular structure of the caking agent saccharide changes by the action of heat. For example, heating the sugar to a syrup at 103-105 ° C, a fondant at 107-115 ° C, a caramel at 115-121 ° C, a toffee at 140 ° C, a drop at 145 ° C, a glaze at 165 ° C It is thought that water is generated from the molecule of the saccharide so as to be converted to the caramel source at 180 ° C. into the caramel at 190 ° C. to be dehydrated, and the molecule of the saccharide undergoes a condensation reaction. For this reason, the molecular weight of the saccharide is increased, and the ability to bond the refractory aggregate with the saccharide as a caking agent is enhanced, and the heat resistance of the saccharide is improved, and the molded article 3 can be obtained by heat treatment. It is possible to improve the strength and heat resistance of the mold.

  The casting can be carried out by pouring a high temperature molten metal into the mold manufactured as described above and casting the casting. At this time, the caking agent which bonds the refractory aggregate in the mold is decomposed by the action of the high temperature of the molten metal, but the saccharides constituting the caking agent are generated to such an extent that water and carbon dioxide gas are generated even if they are decomposed. They do not generate harmful gases and do not deteriorate the environment of the casting site. In addition, since the caking agent saccharide which bonds the refractory aggregate of the mold is thermally decomposed at a relatively low temperature, it is easily pyrolyzed by the heat of the molten metal. Therefore, the mold can be easily disintegrated, and there is no need for impacting the mold or long-term heating at high temperature to decompose the binder in order to remove the casting from the mold. And the casting can be easily removed from the mold.

  Moreover, although the caking agent that bonds the refractory aggregate of the mold is made of saccharides, the heat resistance of the refractory aggregate is enhanced by heat treatment, and the heat resistance of the saccharide is improved, so that the strength of the mold is increased. And heat resistance is improved. Therefore, for example, even when a large amount of molten metal is poured into the mold, the mold is not broken, and an accident such as breakage of the mold when pouring into the mold can be prevented in advance.

  Here, when a thermosetting resin such as a phenol resin is used in combination with a saccharide as a caking agent as described above, the thermosetting resin having high heat resistance can increase the bonding strength of the fireproof aggregate. The mold strength and heat resistance can be further improved.

  Thus, a mold having high strength and heat resistance can be obtained by using a thermosetting resin such as a phenol resin as a caking agent in combination, but when using a thermosetting resin, it is possible to use a molten metal At the time of pouring, harmful gases may be generated, and the mold disintegratability also decreases. For this reason, when using thermosetting resins, such as a phenol resin, together, it is set to the quantity of 80 mass% or less with respect to the whole quantity of a caking agent as stated above, and it is 50 mass% or less Is more preferred. Moreover, in order to obtain the effect by using thermosetting resin together as a caking agent, it is preferable that thermosetting resin is 10 mass% or more with respect to the whole quantity of a caking agent, and the high effect by combined use is acquired For this reason, it is more preferable that the thermosetting resin is 25% by mass or more based on the total amount of the caking agent.

  Next, a specific example of the production of the mold will be described with reference to FIGS. 1 and 2. FIG. 1 shows an example of an apparatus for forming a molding 3 using water vapor. As shown in FIG. 1 (a), an injection port 7 is provided on the upper surface of a mold 2 provided with a cavity 6 inside, and an exhaust port closed on the lower surface of the mold 2 with a mesh 8 such as a wire mesh. 9 is provided. The mold 2 can be divided vertically or horizontally. Further, the binder coated refractory 1 is stored in a hopper 10, and an air supply pipe 12 with a cock 11 is connected to the hopper 10. Then, after matching the nozzle hole 13 at the lower end of the hopper 10 with the inlet 7 of the mold 2, air is blown into the hopper 10 to pressurize it by switching the cock 11 from closed to open. The binder coated refractory 1 is blown into the mold 2 to fill the cavity 6 of the mold 2 with the binder coated refractory 1. Since the outlet 9 is closed by the mesh 8, the binder coated refractory 1 does not leak from the outlet 9. When a plurality of inlets 7 and outlets 9 are provided in the mold 2 as in the embodiment of FIG. 1, the cinder coated refractory 1 is inserted from one or a plurality of locations among the plurality of inlets 7. Just do it.

  Here, since the coating layer of the binder coated refractory 1 coated on the refractory aggregate is made of solid binder, the binder coated refractory 1 does not have adhesiveness on the surface. , The liquidity is good. Therefore, when the binder-coated refractory 1 is filled in the mold 2 as described above, the binder-coated refractory 1 can be smoothly poured into the cavity 6 of the mold 2, and the mold having a good filling property 2 can be filled with the binder coated refractory 1 and can prevent the occurrence of the filling failure.

  After the cinder coated refractory 1 is filled in the mold 2 as described above, the hopper 10 is removed from the inlet 7 of the mold 2 and, as shown in FIG. Connect 14 Water vapor and heating gas can be selectively supplied to the air supply pipe 14, and the cock 15 of the air supply pipe 14 is opened to blow the water vapor into the cavity 6 of the mold 2 first.

  When steam is blown into the mold 2 in this way, in the initial step of blowing steam, the steam comes into contact with the surface of the binder coated refractory 1 so that the latent heat from the steam is the binder coated refractory 1 As a result, the water vapor is condensed and condensed water is produced on the surface of the binder coated refractory 1. Since the binder in the coating layer on the surface of the binder-coated refractory 1 is solid, the binder-coated refractory 1 can not be bonded with each other as it is solid, but in this way, the binder-coated refractory is used as such When condensed water is supplied to the surface of object 1, sugars in the solid state in the caking agent absorb the condensed water and swell to form paste, and the caking agent becomes wet to form tackiness. . As a result, the binder coated refractory 1 can be bonded by the tackiness of the binder in the coating layer on the surface.

  Next, the binder coated refractory 1 is heated by the latent heat of condensation of the water vapor blown into the mold 2 and the sensible heat. Since the steam has high latent heat and sensible heat, the temperature of the binder coated refractory 1 rapidly rises to around 100 ° C. by the latent heat transferred when the steam condenses. As described above, the time during which the binder coated refractory 1 is heated to around 100 ° C. by the heat transfer of the latent heat of the steam depends on the temperature of the steam, the flow rate of blowing into the mold 2, and the caking agent in the mold 2 Although it changes with the filling amount of the coated refractory 1, etc., it is usually a short time of about 3 to 30 seconds. The water vapor blown into the mold 2 from the inlet 4 heats the binder coated refractory 1 in the mold 2 and then is exhausted from the outlet 9. At this time, it is possible to evaporate and dry the water acting on the caking agent on the surface of the caking agent coated refractory 1, and it is possible to solidify or cure the saccharide of the caking agent. In this way, it is possible to form in the forming die 2 a molded product 3 bonded with the caking agent in which the refractory aggregate of the caking agent coated refractory 1 is solidified or hardened.

  Further, after the temperature of the binder coated refractory 1 has risen to around 100 ° C., the supply to the air supply pipe 14 may be switched to the heating gas, and the heating gas may be blown into the mold 2. The heating gas may be any one having a water content lower than that of the above-described water vapor, and heated air can be used. For example, the air in the atmosphere may be heated and supplied to the air supply pipe 14 as a heating gas. The mixed gas can also be used as a heating gas by mixing the above-described steam with heating air to reduce the water content. The temperature of the heating gas is not particularly limited, as long as it is 100 ° C. or more and a temperature at which the caking agent of the caking agent coated refractory 1 solidifies or hardens. The upper limit of the temperature is not particularly set as long as it is not higher than the temperature at which the binder is decomposed.

  When steam is blown into the mold 2 as described above, the temperature of the binder coated refractory 1 can be rapidly raised to around 100 ° C. by the latent heat transferred when the steam condenses. In order to raise the temperature to 100 ° C. or more, it is necessary to evaporate the condensed water on the surface of the binder coated refractory 1. And although this condensed water is evaporated by the heating by the steam which will be blown after that, as mentioned above, since steam contains much water, the efficiency which evaporates the condensed water is low. Therefore, as described above, the heating gas is blown into the mold 2 and the heating gas is a dry gas having a smaller amount of moisture than water vapor and having a low humidity. The condensed water can be evaporated and dried in a short time. Here, when the evaporation experiment of water is carried out with a stream of steam and heated air, the evaporation of water in heated air becomes larger than the evaporation rate of water in steam at a temperature around 170 ° C. It is reported (T.Yosida, Hyodo, T., Ind.Eng.Chem.Process Des.Dev., 9 (2), 207-214 (1970)). As seen in this report, by blowing the heating gas into the mold 2, the condensed water can be evaporated and dried in a short time as compared with the case where the steam is continuously blown.

  Therefore, the temperature of the binder coated refractory 1 can be raised to 100 ° C. or more in a short time after starting to blow the heated gas into the mold 2, and the caking of the binder coated refractory 1 can be performed. It is possible to increase the speed of raising the temperature in the mold 2 above the temperature at which the agent solidifies or hardens. And as a result, it becomes possible to shape | mold the molding 3 by short heating time.

  The time for blowing the heating gas into the mold 2 is the temperature of the heating gas, the flow rate of blowing into the mold 2, the filling amount of the binder coated refractory 1 in the mold 2, and the condensed water in the mold 2. Although it varies depending on the amount, it is usually a short time of about 5 to 60 seconds. Therefore, it is possible to perform molding of the molded product 3 in a short time of about 10 seconds to 1 minute from the start of blowing steam into the mold 2 to the end of blowing the heating gas.

  Here, as steam to be blown into the mold 2, saturated steam can be used as it is, but superheated steam can also be used. Superheated steam is steam in a completely gaseous state, which is further heated to a temperature above the boiling point by further heating saturated steam, and is dry steam at 100 ° C. or above. The superheated steam obtained by heating the saturated steam may be one expanded at a constant pressure without increasing the pressure, or may be pressurized steam at an increased pressure without expansion. The temperature of the superheated steam blown into the mold 1 is not particularly limited, and the temperature of the superheated steam can be increased to about 900 ° C. Therefore, if the temperature is set between 100 and 900 ° C., the temperature can be set as needed. Good. Since the superheated steam is thus a high temperature dry steam, it is possible to make it unnecessary to use the heating gas as described above.

  As described above, at the beginning of the process of blowing steam into the mold 2, it is necessary to make the caking agent of the caking agent coated refractory 1 wet with water. At this time, even if superheated steam is used as steam, since the temperature is lower than that of superheated steam, the temperature is lower than that of superheated steam, so when superheated steam is blown into the mold 2, the superheated steam Latent heat is taken away by the binder coated refractory 1, and condensed water is generated from the superheated steam, and the condensed water can make the binder of the binder coated refractory 1 wet. However, in the case of using superheated steam as steam, the formation of condensed water is insufficient and the binder of the binder coated refractory 1 can not be uniformly wet at the initial stage of the step of blowing the steam into the mold 2 There is.

  In such a case, it is preferable to supply moisture to the surface of the binder coated refractory 1 at the beginning of the process of blowing water vapor into the mold 2. For example, at the beginning of the process of blowing steam into the forming die 2, saturated steam is supplied to the air supply pipe 14, and saturated steam is blown into the forming die 2 from the air supply pipe 14. Since condensed water is easily generated from the saturated steam, this condensed water generated from the saturated steam in the mold 2 can be supplied as moisture to the binder coated refractory 1 and caking The binder of the agent coated refractory 1 can be uniformly wetted. After that, the supply to the air supply pipe 14 is switched from saturated water vapor to superheated water vapor, and the superheated water vapor is blown into the forming die 2 from the air supply pipe 14. At this time, it is desirable to set the ratio of the time for blowing saturated steam to the time for blowing superheated steam in the range of about 1: 9 to 5: 5.

  In the above embodiment, the condensed water of the water vapor blown into the forming die 2 is supplied to the surface of the binder coated refractory 1 so that the moisture of the condensed water causes the caking agent to be in a wet state. After the binder-coated refractory 1 is filled in the mold 2, water may be injected into the mold 2 to supply moisture to the binder-coated refractory 1. For example, after the cinder coated refractory 1 is filled in the mold 2, water is injected from the injection port 7 into the mold 2, and the caking agent of the cinder coated refractory 1 is wet with this water Then, there is a method of blowing water vapor from the injection port 7, and excess water injected into the mold 2 is discharged from the discharge port 9 by the injection of water vapor. As described above, if moisture is supplied to the mold 2 filled with the binder coated refractory 1 to wet the binder, the water vapor is superheated from the beginning of the process of blowing water vapor into the mold 2. Water vapor can be used.

  Further, as shown in FIG. 1 (a) to (b), when the cinder coated refractory 1 is filled in the cavity 6 of the mold 2, the cinder coated refractory 1 is preheated, The preheated binder coated refractory 1 may be supplied to the mold 2 and filled in the cavity 6. By preheating the binder coated refractory 1 in this way, it is possible to suppress the temperature drop of the water vapor blown into the mold 2 and above the temperature at which the binder of the coating layer dries and solidifies. It is possible to increase the speed of raising the temperature in the mold to as long as possible, and it is possible to shorten the time for molding the molding 3.

  The preheating of the binder coated refractory 1 can, for example, take place in the hopper 10 storing the binder coated refractory 1. Although the temperature which preheats the binder coated refractory 1 is not specifically limited, The range of about 30-100 degreeC is preferable.

  As described above, the molded product 3 can be molded in the mold 2 by blowing steam into the mold 2 filled with the binder coated refractory 1. Then, the mold 2 is opened, the molded product 3 is taken out, and the molded product 3 is put into the heat treatment container 4 and heat treated.

  FIG. 2A shows an example of the heat treatment container 4 which is formed by providing the heat generating means 18 in the container main body 17, and the opening 20 with the door 19 is formed in the front surface of the container main body 17. The heating means 18 is provided on the side wall of the container body 17 or the like. The heat generating means 18 may be anything as long as it can heat the interior of the heat treatment container 4 by self-heating due to combustion or electrical resistance, but for example, a gas burner, an electric heater or the like can be used, For example, the heat treatment container 4 can be formed by a hot air circulating dryer.

  FIG. 2 (b) shows another example of the heat treatment container 4, wherein the inlet 21 through which water vapor is blown into the container body 17 is at the bottom and the exhaust outlet 22 from which water vapor is discharged from the container body 17 is at the top Provided in By closing the opening 20 on the front surface of the container body 17 with the door 19, the inside of the heat treatment container 4 is sealed except for the inlet 21 and the exhaust 22. The steam generator 23 is connected to the inlet 21. The steam generation device 23 is formed by including a boiler and a superheater, and heats water in the boiler to generate steam (saturated steam) and further heats the steam in the superheater to form a superheated steam as a heat treatment vessel. It is made to supply to 4.

  Then, the molded product 3 molded by the mold 2 as described above is placed in the heat treatment container 4, and the molded product 3 is heated and heated at a predetermined temperature for a predetermined time in the heat treatment container 4 to obtain a mold. It can be done. Here, in the heat treatment container 4 of FIG. 2 (a), by setting the inside of the heat treatment container 4 to a predetermined temperature in advance by the heat generation means 18, the molding 3 can be heat-treated at an accurate temperature. Moreover, in the heat processing container 4 of FIG.2 (b), the heat processing of the molded object 3 can be carried out with high thermal efficiency highly efficiently, and the time of heat processing can be shortened.

  Next, the present invention will be specifically described by way of examples.

(Production example of binder coated refractories)
10 kg of flattery silica sand heated to 140 ° C. was placed in a whirl mixer, to which was added an aqueous solution prepared by dissolving or dispersing saccharides shown in Table 1 in 450 g of water, and kneaded for about 90 seconds. At this time, as shown in Table 1, a hardening agent for saccharides and a phenol resin were further added as needed, and this kneading was performed. After disintegration, 30 g of calcium stearate was added as a lubricant, the mixture was kneaded for 15 seconds, and further aeration was performed to obtain a caking agent-coated refractory (1) to (10) coated with a saccharide coating layer. . In the binder coated refractories (1) to (10), the mass ratio of the coating layer was 2.5% by mass.

  Here, as shown in Table 1, as saccharides, dextrin ("NDP-4C" manufactured by Lignite Co., Ltd. "NDP-4C", "NDP-3" manufactured by Lignite Co., Ltd. "NDP-6") ), And top white sugar (containing 98.2% by mass of sucrose and 0.7% by mass of reducing sugar). When dextrins are arranged in descending order of molecular weight, they are in the order of "NDP-4C" and "NDP-13", and in case of enzyme-modified dextrins in descending order of molecular weight in the order of "NDP-6" and "NDP-4C" is there. In addition, citric acid was used as a curing agent, and was used by dissolving in water. Moreover, as a phenol resin, novolak type phenol resin (Lignite Co., Ltd. product "# 4800"; softening point 91 ° C), resol type phenol resin (Lignite Co., Ltd. product "LT-9"; softening point 90 ° C, gelation time 120 seconds (at 150 ° C.) were used.

(Examples 1 to 10)
A mold was manufactured using the binder coated refractories (1) to (10) prepared as described above. That is, a mold having a cavity size of 20 mm × 10 mm × 80 mm is preheated to 120 ° C., and a binder coated refractory is blown into the mold with an air pressure of 0.1 MPa and filled. did. Next, connect the air supply pipe to the mold and use saturated steam with a gauge pressure of 0.4 MPa and a temperature of 143 ° C generated by the boiler with a superheated steam generator ("GE-100" manufactured by Nomura Engineering Co., Ltd.) Superheated steam at 350 ° C. and a gauge pressure of 0.45 MPa obtained by heating was supplied at a flow rate of 60 kg / h and blown into the mold for 20 seconds.

  In this way, a molded product of dimensions of 20 mm × 10 mm × 80 mm was molded in the mold, and the molded product was removed from the mold and taken out. At this time, when the mold was opened, the odor was measured by sniffing with the nose, and the bending strength of the molded product immediately after removal from the mold was measured according to JIS K 6910. The results are shown in Table 2.

  As seen in Table 2, in Examples 1 to 7 and 10 using a caking agent-coated refractory containing only saccharides as a caking agent, almost no odor is felt, and a phenol resin is used in combination Also in Examples 8 and 9 where the content of the phenol resin was small, the odor was weak. As for the bending strength of the molded product, Examples 1 to 6 using a caking agent-coated refractory containing only saccharides as a caking agent show low values, and are implemented by adding citric acid as a hardening agent In Examples 7 and 10 and in Example 8.9 in which the phenol resin was used in combination, it was somewhat high.

  Next, the molded product taken out from the inside of the mold as described above is placed in a hot-air circulating dryer, the internal temperature of which is previously set to 80 ° C., 120 ° C., 180 ° C., 220 ° C., 250 ° C., and heated for 60 minutes Treated (after cure). The bending strength of the mold obtained by the heat treatment was measured according to JIS K 6910. The results are shown in Table 3.

  It is confirmed that the bending strength is greatly increased from the values in Table 2 to the values in Table 3 by heat treatment and after curing of the molded product taken out from the inside of the mold, and the strength is greatly improved. Ru. Note that when the heating temperature is 80 ° C., the heating temperature is preferably 100 ° C. or higher, and it is more preferable that the heating temperature is 150 ° C. or higher since the effect of improving the strength is not sufficiently obtained Be done. Further, since the bending strength is lowered at the heating temperature of 250 ° C., it is preferable to set the heating temperature to 240 ° C. or less.

  Moreover, when heat-processing the molded object taken out from the inside of a shaping | molding die as mentioned above with a hot air circulation type drier of 220 degreeC, the heating time was set to 5 minutes, 15 minutes, 30 minutes, and 90 minutes. The bending strength of the mold obtained by the heat treatment was measured according to JIS K 6910. The results are shown in Table 4.

  As can be seen from the results in Table 4, when the heat treatment time is 5 minutes, the effect of improving the strength is not sufficiently observed, so the heat treatment time is preferably 10 minutes or more, and preferably 30 minutes or more. It is confirmed that the heating time is more preferable. Further, when the heating time reaches 90 minutes, it is lower than the bending strength of 220 ° C. × 60 minutes in Table 3. It can be said that the heating time is preferably set shorter than 80 minutes.

  Next, in Examples 2, 3, 9, and 10, 2.5 g of a sample was cut out of the molded product before heat treatment and the mold after heat treatment at 180 ° C., 220 ° C., and 250 ° C., The amount of gas generation was measured for this sample. The measurement was performed by reading the amount of gas every 10 seconds under an atmosphere of 700 ° C. using a “cast sand gas generation rate tester (type: manual reading type)” manufactured by Hashimoto Rika Co., Ltd. The results every 30 seconds are shown in Table 5.

  As seen in Table 5, it is confirmed that the amount of gas generation can be further reduced by performing the heat treatment, and the amount of gas generation in casting can be reduced.

(Examples 11 and 12)
Binder coated refractor (3) or binder coated refractor using a mold which molds a mold with a diameter of 109 mm, a height of 74 mm and a weight of about 735 g and which molds the mold is preheated to 120 ° C. (10) was filled by blowing in an air pressure of a gauge pressure of 0.1 MPa. Next, connect the air supply pipe to the mold and use saturated steam with a gauge pressure of 0.4 MPa and a temperature of 143 ° C generated by the boiler with a superheated steam generator ("GE-100" manufactured by Nomura Engineering Co., Ltd.) Superheated steam at 350 ° C. and a gauge pressure of 0.45 MPa obtained by heating was supplied at a flow rate of 100 kg / h and blown into a mold for 60 seconds.

  Thus, the molded product was molded in the mold, and the molded product was removed from the mold and taken out. Then, the molded product was placed in a hot air circulating dryer whose internal temperature was set at 250 ° C., and heat treatment (after curing) was performed for 30 minutes to obtain a mold as a core.

  The mold obtained by heat treatment as described above was set as a core in a green mold, and a cast iron molten metal equivalent to FC 200 and having a casting temperature of 1250 to 1300 ° C. was cast therein. Further, for comparison, a cast iron molten metal was similarly cast and tested using a molded product before heat treatment as a core. Then, the generation of odor and smoke during casting was observed, the state of seizure to the core was observed, and the disintegration of the core when the casting was taken out was observed. The results are shown in Table 6.

  As seen in Table 6, when using a molded product before heat treatment as a mold, there is a problem with heat resistance due to occurrence of seizure, but when this is heat treated and used as a mold, there is no occurrence of seizure, It is confirmed that heat resistance can be improved. Although the heat resistance is thus improved, the mold disintegrability is good and there is no problem.

(Heat resistance test of saccharides)
An experiment was conducted to measure heat resistance using enzyme-modified dextrin "NDP-3" as a saccharide. The target sample of the test is "NDP-3" which is not heat-treated, "NDP-3" which is heat-treated for 60 minutes in a dryer at 250 ° C, 225g of "NDP-3" and 25g of citric acid and water is added. The mixture was well mixed, placed in a petri dish, dried at a temperature of 105.degree. C., and then heat-treated in a dryer at 250.degree. C. for 60 minutes.

  Each sample was subjected to thermal analysis at a temperature rising rate of 10 ° C./min in a nitrogen atmosphere using a differential heat and heat weight simultaneous measurement apparatus “DTG-60H” manufactured by Shimadzu Corporation, as shown in FIG. A graph of temperature-remaining mass was obtained. The residual mass at 400 ° C. and 600 ° C. is determined from this graph and is shown in Table 7.

  As can be seen from the graph of FIG. 3 and Table 7, the remaining mass is increased by heat-treating “NDP-3”, that is, the mass loss due to heating is reduced, and the heat treatment is performed. The heat resistance of "NDP-3" is improved. In particular, the addition of citric acid to "NDP-3" further reduces the mass loss. This suggests that the saccharides are polymerized and the molecular weight is increased by heat treatment, and the strength of the template is improved as shown in Tables 3 and 4, and as shown in Table 6. The improvement of the heat resistance of the mold is considered to be attributable to the fact that the saccharide is polymerized by heat treatment and the strength and heat resistance of the saccharide itself are increased.

1 caking agent coated refractory 2 molding die 3 molding 4 heat treatment container

Claims (16)

  A caking agent-coated refractory formed by covering a solid coating layer containing saccharides as a caking agent on the surface of the fireproof aggregate is filled in a forming die, and water vapor is blown into the forming die to form a caking agent. By heating the coated refractory, the caking agent of the coating layer is solidified or cured, whereby a molded article having the refractory aggregate bonded with the caking agent is molded in a mold, and the molded article is molded A method for producing a mold, comprising heat-treating a molded product after taking it out of the above.   The method for producing a mold according to claim 1, wherein the heat treatment of the molding is carried out at a temperature of 100 to 350 ° C. The method for producing a mold according to claim 1 or 2, wherein the heat treatment of the molding is carried out for 10 to 200 minutes.   The method for producing a mold according to any one of claims 1 to 3, wherein the molded product taken out of the mold is subjected to heat treatment in a heat treatment container.   Water vapor is blown into a mold filled with a binder-coated refractory to supply condensed water of the water vapor into the mold, thereby imparting tackiness to the saccharide of the binder and subsequently blowing into the mold. The method for producing a mold according to any one of claims 1 to 4, wherein the caking agent is solidified or cured by heating the caking agent coated refractories by the latent heat of condensation of steam and the sensible heat.   The mold according to claim 5, characterized in that the heating of the binder coated refractory in the mold is performed by the steam blown into the mold and the heating gas blown into the mold following the steam. Manufacturing method.   The method according to claim 6, wherein the heating gas is heated air.   The method for manufacturing a mold according to claim 6, wherein the heating gas is a mixed gas of water vapor and air.   The method for producing a mold according to any one of claims 1 to 8, wherein the steam is superheated steam.   The method for producing a mold according to any one of claims 1 to 9, wherein the coating layer of the binder-coated refractory contains a carboxylic acid.   The method for producing a mold according to any one of claims 1 to 10, wherein a thermosetting resin is contained in the coating layer of the binder coated refractory in addition to the saccharide as the binder.   The method for producing a mold according to claim 11, wherein a phenol resin is used as the thermosetting resin.   The method for producing a mold according to claim 11 or 12, wherein the content of the thermosetting resin in the binder is 80% by mass or less. The method for producing a template according to any one of claims 1 to 13, wherein the saccharide is selected from monosaccharides , oligosaccharides and polysaccharides.   The caking agent-coated refractory is filled in the mold, and water is supplied to the mold to impart adhesiveness to saccharides of the caking agent, and then superheated steam is blown into the mold to produce superheated steam. The method for producing a mold according to any one of claims 1 to 4, wherein the caking agent is solidified or cured by heating the caking agent coated refractory with the latent heat of condensation and the sensible heat.   A binder coated refractory is filled in a mold, and saturated steam is blown into the mold to supply condensed water of the steam to the binder to make the saccharides tacky, and subsequently, the mold is molded. The method according to any one of claims 1 to 4, characterized in that the caking agent is solidified or cured by blowing in superheated steam and heating the binder coated refractory with the latent heat of condensation of the superheated steam and sensible heat. Manufacturing method of mold.

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