JP5037112B2 - Casting structure - Google Patents

Description

  The present invention relates to a structure such as a mold used in manufacturing a casting, a method for manufacturing the structure, and a method for manufacturing a casting using the structure.

  For castings, in general, a mold having a cavity is formed with casting sand based on a wooden mold or a mold, and a core is disposed in the cavity as needed, and then a molten metal is supplied to the cavity. Manufactured.

  The manufacture of wooden molds and molds requires skill in processing and expensive equipment, and there are disadvantages such as expensive and heavy disposal, as well as disposal problems, making it difficult to use in addition to mass-produced castings. Moreover, since the sand mold | die using casting sand has added the binder to normal sand, it is made to harden | cure and the shape is hold | maintained, a recycling process process becomes essential for reuse of sand. There is also a problem that waste such as dust is generated during the regeneration process. In addition, when the core is manufactured in a sand mold, it is difficult to handle due to the weight of the core itself in addition to the above problems, and furthermore, there are conflicting performances of strength maintenance during casting and core removal after casting. Required.

  As a technique for solving such a problem, a technique for molding a member used for a mold with, for example, a plastic material that adheres powdered graphite and powdered graphite (see Patent Document 1 below) is known. Moreover, although the technique (refer patent document 2 below) which obtains the structure for casting manufacture containing an organic fiber, an inorganic fiber, an inorganic particle, and a thermosetting resin is known, a thermoplastic resin is not used substantially. .

JP-A-8-90145 JP 2005-349428 A

  In a structure using a conventional thermoplastic resin, the hot strength at the time of casting is low, so the structure for casting production is deformed at the time of casting, so the intended shape of the casting cannot be maintained. Had the problem of being bad.

  The object of the present invention is to provide a casting with a good moldability, light weight, and sufficient hot strength even during casting. An object of the present invention is to provide a casting manufacturing structure, a manufacturing method thereof, and a casting manufacturing method using these.

  The present invention relates to a structure for producing castings containing inorganic fibers, inorganic particles, a resol-based phenol resin having a gel time at 150 ° C. of 1.5 minutes or more, and a thermoplastic resin.

  The present invention also relates to a method for producing a casting manufacturing structure in which inorganic fibers, inorganic particles, a resol-based phenol resin and a thermoplastic resin having a gel time at 150 ° C. of 1.5 minutes or more are melt-kneaded and then molded.

  Moreover, this invention relates to the manufacturing method of the casting which uses the structure for casting manufacture of the said invention.

  ADVANTAGE OF THE INVENTION According to this invention, since it has sufficient hot strength at the time of casting, it is excellent in the shape retainability at the time of casting, and the structure for casting manufacture from which the casting of the intended shape is obtained accurately is provided.

  The structure for producing a casting of the present invention contains inorganic fibers, inorganic particles, a resol-based phenol resin and a thermoplastic resin having a gel time at 150 ° C. of 1.5 minutes or more.

  The content of the inorganic fiber in the structure is preferably 1 to 50% by weight, more preferably 2 to 40% by weight, and particularly preferably 3 to 30% by weight. In addition, the numerical value of this content may be a numerical value of the blending amount in the structure (the same applies hereinafter). Furthermore, the numerical value of this content may be a numerical value when the total of inorganic fibers, inorganic particles, a resol phenol resin having a gel time at 150 ° C. of 1.5 minutes or more, and a thermoplastic resin is 100% by weight. Good (and so on).

  The content of the inorganic fiber of 1% by weight or more suppresses heat shrinkage due to a decrease in the heat resistance of the structure and suppresses the amount of gas generated from the viewpoint of accurately transferring the shape of the structure to the casting. From the viewpoint, the content is preferably 50% by weight or less from the viewpoint that the moldability of the structure is good and the removability of the structure after casting is also good.

  The content of the inorganic particles is preferably 5 to 70% by weight, more preferably 10 to 60% by weight, and particularly preferably 20 to 50% by weight in the structure.

  The content of the inorganic particles is preferably 5% by weight or more from the viewpoint that the effect of adding the inorganic particles described later is more easily expressed, and the content of 70% by weight or less is the moldability of the structure, It is preferable from the viewpoint of excellent shape transferability to a casting.

  In addition, the content of the resol phenol resin having a gel time at 150 ° C. of 1.5 minutes or more is preferably 1 to 70% by weight, more preferably 10 to 60% by weight, and particularly preferably 15 to 50% by weight in the structure.

  When the content of the resol phenol resin having a gel time at 150 ° C. of 1.5 minutes or more is 1% by weight or more, the smoothness of the casting surface is good, and the strength and shape retention of the structure are also good. This content is preferably 70% by weight or less from the viewpoint of improving the moldability of the structure and reducing the amount of gas generated to suppress surface defects of the casting.

  Further, the content of the thermoplastic resin in the structure is preferably 5 to 60% by weight, more preferably 8 to 40% by weight, and particularly preferably 10 to 35% by weight.

  The thermoplastic resin content of 5% by weight or more is preferable from the viewpoint of melt kneading and improving the moldability of the structure for producing castings, and the content is 60% by weight or less. From the viewpoint of reducing the amount of gas generated and suppressing surface defects of the casting.

  The inorganic fiber is a component that mainly forms a skeleton in a state before being used for casting in a structure for producing castings, and maintains its shape without being burned by the heat of molten metal when used for casting. In particular, it is a component that suppresses thermal shrinkage caused by thermal decomposition of the casting production structure by the heat of the molten metal.

  Examples of the inorganic fibers include artificial mineral fibers such as carbon fibers and rock wool, ceramic fibers, alumina fibers, and natural mineral fibers. These inorganic fibers can be used alone or in combination of two or more. Among these, carbon fibers having high strength even at high temperatures are preferable from the viewpoint of effectively suppressing shrinkage associated with thermal decomposition of the structure for casting production, and pitch-based or polyacrylonitrile (PAN) -based carbon fibers are preferably used. More preferably, PAN-based carbon fiber is particularly preferable. These carbon fibers can be used in combination with artificial mineral fibers such as rock wool, inorganic fibers such as ceramic fibers, alumina fibers, and natural mineral fibers.

  The inorganic particles are components that improve the heat resistance of the structure. Examples of the inorganic particles include silica, alumina, mullite, magnesia, zirconia, mica, graphite, obsidian, tungsten, ruthenium, thorium oxide, hafnium oxide, zirconium oxide, beryllium oxide, lime, yttrium oxide, cerium oxide, thallium oxide, and oxide. Lanthanum, calcium carbonate, potassium carbonate, sodium carbonate, sodium bicarbonate, magnesium hydroxide, aluminum hydroxide, silicic acid, zircon, sillimanite, spinel, chromite, holsterite, enstatite, titanium carbide, zirconium carbide, hafnium carbide, carbonized Vanadium, Niobium carbide, Tantalum carbide, Chromium carbide, Molybdenum carbide, Tungsten carbide, Titanium nitride, Zirconium nitride, Hafnium nitride, Tantalum nitride, Zirconium boride Inorganic particles such as copper, hafnium boride, tungsten boride and the like, inorganic particles having a fire resistance of 800 to 4000 ° C., preferably 1000 to 4000 ° C. are preferred, and graphite is preferable from the viewpoint of heat resistance and releasability at the time of molding a structure. Is more preferable. In addition, calcium carbonate is more preferable from the viewpoint of gas defect reduction and releasability at the time of forming a structure. These inorganic particles may be used alone or in combination of two or more. The inorganic particles preferably have a particle size of 200 μm or less. In particular, inorganic particles having a fire resistance of ± 300 ° C., particularly ± 200 ° C. with respect to the casting temperature of the molten metal to be cast are preferable. Here, the fire resistance of the inorganic particles is measured by a measuring method (JIS R2204) using a Zeger cone. Preferred inorganic particles that are commercially available include, for example, graphite (average particle size 56 μm) manufactured by Bogala Graphite Lanka Limited, calcium carbonate manufactured by Sankyo Seimitsu Co., Ltd., trade name “Escalon # 800”, calcium shiraishi Co., Ltd. For example, calcium carbonate having a trade name of “Whiteon B” may be used.

  The resol-type phenol resin (hereinafter also referred to simply as “resol-type phenol resin”) having a gel time at 150 ° C. of 1.5 minutes or more used in the present invention is a kind of thermosetting resin. If the gel time at 150 ° C. is 1.5 minutes or more, the resol phenolic resin of the present invention is excellent in structure strength and shape retention, preferably 2 minutes or more, preferably 10 minutes or less, more preferably Is less than 6 minutes. Therefore, such gel time is also more preferably 2 minutes to 10 minutes, and further preferably 2 minutes to 6 minutes.

  Moreover, although it is not certain, the resol phenolic resin of the present invention has a good dispersion state because the gel time at 150 ° C. is 1.5 minutes or more and the curing of the resol phenolic resin at the time of melt kneading proceeds slowly. As a result, a structure for producing castings having sufficient hot strength can be obtained. Therefore, the structure has excellent shape retention at the time of casting, and the effect of the present invention that a casting having the intended shape can be obtained. it is conceivable that.

  The gel time can be determined according to a measurement method (JIS K6300) using a curast meter.

  The weight average molecular weight of the resol-based phenolic resin of the present invention is preferably 3000 to 20000, more preferably 5000 to 15000, from the viewpoint of the strength and shape retention of the structure. The weight average molecular weight was determined by using gel permeation chromatography (GPC), chloroform as a solvent, GM HHR-H × 2 (manufactured by Tosoh), a flow rate of 1.0 mL / min, a column temperature of 40 ° C., and a detector. A differential refractive index detector (RI) can be obtained by converting styrene having a known molecular weight as a reference.

  In the present invention, a commercially available resol phenol resin having a gel time at 150 ° C. of 1.5 minutes or more can be used. Examples of such a resol-based phenol resin include a product name Belpearl S890 (gel time at 150 ° C .: 3 minutes, weight average molecular weight: 10,000) manufactured by Air Water Co., Ltd.

  The thermoplastic resin used in the present invention is a component necessary for forming structures of various shapes by melting and fluidizing.

  The thermoplastic resin used in the present invention is preferably a thermoplastic resin having a low melting point because melt kneading at a low temperature contributes to the dispersibility of the resol phenolic resin of the present invention. As a preferable thermoplastic resin used in the present invention, it is preferable to use a thermoplastic resin that can form structures of various shapes by melt-kneading and fluidizing at 170 ° C. or lower. It is a thermoplastic resin having a temperature of 160 ° C. or lower, more preferably 150 ° C. or lower. The lower limit is not particularly limited, but a thermoplastic resin having a melting point of 80 ° C. or higher, more preferably 90 ° C. or higher is preferable. Examples of the thermoplastic resin include polyethylene, polyvinyl chloride, polylactic acid, polybutylene succinate, polyvinyl alcohol, and ethylene-vinyl alcohol copolymer. A thermoplastic resin selected from polyethylene and polylactic acid is preferred.

  In addition, melting | fusing point of a thermoplastic resin is a value calculated | required from the crystal melting endothermic peak temperature by the temperature rising method of differential scanning calorimetry (DSC) based on JIS-K7121.

  The thermoplastic resins may be used alone or in combination of two or more. Moreover, when using a high-melting-point thermoplastic resin, it is preferable to use it by prescription which can be melt-kneaded at low temperature (for example, 170 degrees C or less) by combined use with a plasticizer.

  In the present invention, as a raw material for producing a structure for producing castings, a stabilizer (antioxidant, ultraviolet absorber, etc.), mold release agent (fatty acid, fatty acid metal salt, oxyfatty acid, Fatty acid ester, aliphatic partially saponified ester, paraffin, low molecular weight polyolefin, fatty acid amide, alkylene bis fatty acid amide, aliphatic ketone, fatty acid lower alcohol ester, fatty acid polyhydric alcohol ester, fatty acid polyglycol ester, modified silicone), etc. You can also.

  The casting manufacturing structure obtained by the present invention is applied to a main mold having a cast product-shaped cavity on the inner surface, a core used in the main mold, or a pouring member such as a runner. However, since the structure for producing a casting according to the present invention is excellent in surface smoothness and a casting having a good casting surface can be obtained, application to a main mold and a core is preferable.

  In the method for producing a structure for producing a casting according to the present invention, inorganic fibers, inorganic particles, a resol phenol resin and a thermoplastic resin are molded after melt-kneading, and a known method used in molding a thermoplastic resin. Can be adopted. For example, inorganic fibers, inorganic particles, resole phenolic resin, and thermoplastic resin are uniformly mixed using a high-speed stirrer or low-speed stirrer, and then melt-kneaded with a single-screw or multi-screw extruder having sufficient kneading ability. The method can be adopted. Further, for example, after mixing inorganic fibers, inorganic particles and thermoplastic resin, the resol phenol resin may be mixed and melt-kneaded. After the thermoplastic resin, inorganic particles and inorganic fiber are mixed and pelletized, the resole The phenolic resin may be mixed and melt-kneaded, and the mixing method and melt-kneading method are not limited.

  The reason why the effect of the present invention is manifest is not clear, but it is considered that a structure in which the resol phenolic resin is better dispersed can be obtained by melting and kneading at a low temperature. Since the resole phenolic resin that is better dispersed in the body is cured and cross-linked, it has sufficient hot strength at the time of casting, so that the effect of the present invention is obtained to obtain a structure for producing castings that is excellent in shape retention. It is considered to be expressed. Accordingly, the temperature for melt kneading is preferably 170 ° C. or lower, more preferably 160 ° C. or lower, and further preferably 155 ° C. or lower. Further, the lower limit of the melt kneading temperature of the inorganic fibers, inorganic particles, resol phenol resin and thermoplastic resin is not particularly limited as long as the temperature can be melt kneaded, but is preferably 90 ° C. or more, more preferably Is 100 ° C. or higher, more preferably 110 ° C. or higher. From this viewpoint, the temperature for melt kneading is preferably 90 to 170 ° C, more preferably 100 to 165 ° C, and still more preferably 110 to 155 ° C.

  The melt kneading temperature is preferably 5 to 30 ° C. higher than the melting point of the thermoplastic resin. Depending on the purpose, various stabilizers, ultraviolet absorbers, flame retardants, internal mold release agents, lubricants, plasticizers, and the like can also be added. In the present invention, the structure for casting production is produced by mixing each raw material in a solid state using a known kneading technique, for example, a Henschel mixer, a ribbon blender or the like, and further kneading while melting the polymer using an extruder or the like. It is also possible to use a method of In general, the melt-kneaded mixture is preferably used for molding in the form of pellets, rods, powders or the like. Such a mixture can be made uniform by a mixer and used for injection molding, extrusion molding, compression molding and the like under normal molding conditions.

  In the present invention, the mixture obtained by melt-kneading is molded by a molding method such as injection molding, blow molding, extrusion molding, inflation molding, vacuum forming after sheet processing, pressure forming, vacuum pressure forming, etc. A structure can be obtained. In particular, an injection molding method is preferable, and in addition to a general injection molding method, gas injection molding, injection press molding, or the like can be employed. If an example of the injection molding conditions suitable for the structure for casting manufacture of this invention is given, cylinder temperature will be more than the flow start temperature of the structure for casting manufacture, Preferably it is 90-170 degreeC, More preferably, it is 100-165 degreeC. The mold temperature is suitably set to −20 ° C. or less of the flow start temperature of the mixture obtained by melt kneading. If the molding temperature is too low, the operability becomes unstable or overloading occurs, such as a short circuit in the molded product. Conversely, if the molding temperature is too high, the mixture obtained by melt-kneading, particularly the resin components, will decompose. In addition, the strength of the resulting molded product is likely to decrease, or problems such as coloring may occur.

  If an example of the preferable aspect of the manufacturing method of the structure for casting manufacture of this invention is given, (1) Inorganic fiber 5-30 weight%, (2) Inorganic particle 20-40 weight%, (3) Gel time in 150 degreeC 20 to 50% by weight of a resole phenolic resin that is 1.5 minutes or longer, and (4) a thermoplastic resin having a melting point of 160 ° C. or lower, preferably 10 to 30% by weight selected from polyethylene and polylactic acid, Examples of the method include molding after melt-kneading at 170 ° C. or lower. Here, the weight% of each component is a numerical value when the total of (1) to (4) is 100% by weight.

  Next, a casting manufacturing method using the casting manufacturing structure obtained according to the present invention will be described based on preferred embodiments thereof. In the casting manufacturing method of the present embodiment, the predetermined casting manufacturing structure obtained as described above is embedded in a predetermined position in the casting sand to form a mold. As the foundry sand, a conventional one that has been conventionally used for producing this type of casting can be used without any particular limitation. The foundry sand need not be cured with a binder, but may be cured as necessary. When the structure for casting production is a hollow core, the core does not need to be filled with foundry sand, but can be filled.

  Then, the molten metal is poured from the pouring gate and cast. At this time, in the structure of the present invention, the hot strength is maintained and the thermal shrinkage accompanying the thermal decomposition of the structure for casting production is suppressed. The body itself is hardly damaged, and there is hardly any insertion of molten metal into the casting structure or adhesion of foundry sand.

  After the casting is finished, the casting is cooled to a predetermined temperature, the casting frame is disassembled to remove the casting sand, and the casting manufacturing structure is removed by blasting to expose the casting. At this time, since the thermoplastic resin is thermally decomposed, it is easy to remove the casting manufacturing structure. Thereafter, post-processing such as trimming is performed on the casting as necessary to complete the manufacturing of the casting.

  Since the casting manufacturing method of the present embodiment uses a casting manufacturing structure having sufficient hot strength and excellent shape retention, it is possible to manufacture a casting having excellent dimensional accuracy and surface smoothness. Moreover, since the voids can be formed inside the cast structure by thermal decomposition of the thermoplastic resin or the like, and the cast manufacturing melted structure after casting can be easily removed, the waste treatment can be performed as compared with the conventional case. In addition to simple operation, the amount of waste generated can be greatly reduced. In addition, since it is not necessary to harden the foundry sand with a binder, the reclaiming treatment of the foundry sand becomes simple.

[Example 1]
<Combination of raw materials>
Inorganic fiber: PAN carbon fiber (Mitsubishi Rayon Co., Ltd., trade name “Pyrofil chopped fiber TR03CMTR12CM”, fiber length: 3 mm)
Inorganic particles: BP8083 (Bogala Graphite Lanka Limited, graphite having an average particle size of 56 μm)
Resole phenolic resin: manufactured by Air Water Co., Ltd., trade name Belpearl S890 (gel time at 150 ° C .: 3 minutes, weight average molecular weight: 10,000), represented as “Bellpearl” in the table.
-Thermoplastic resin: Polyethylene ("Novatec HD HS490P" manufactured by Nippon Polyethylene Co., Ltd.)
Structure composition (% by weight): inorganic fiber / inorganic particles / resole phenol resin / thermoplastic resin = 10/34/36/20

<Manufacture of casting structures>
The above raw materials were melt-kneaded at 140 ° C. using a test kneader (Labo Plast Mill 40C, manufactured by Toyo Seiki Co., Ltd.). The obtained mixture for a structure for producing castings was sandwiched between two metal plates together with a mold having a thickness of 1.0 mm, pre-pressurized at 5 kg / cm ² for 3 minutes at a temperature similar to the melt kneading temperature, and then 200 kg The sheet was further pressed for 1 minute at / cm ² to produce a 1.0 mm thick sheet. The obtained sheet is heated to the softening temperature of the sheet, wound around a cylindrical paper tube having an outer diameter of 30 mm, and used for manufacturing a cylindrical casting shown in FIG. 1 having an inner diameter of 30 mm (outer diameter of 32 mm) × height of 100 mm. A structure was obtained.

<Casting of castings>
The obtained structure for casting production of φ32 mm × 100 mm (shown in FIG. 1) is embedded in a molding sand joined with a ceramic pipe and cured with a binder as shown in FIG. Castings were produced at a filling temperature of 1380 ° C. The shape retention of the obtained casting was evaluated as follows, and the results are shown in Table 1.

[Casting shape retention]
The volume deformation rate was obtained from the volume of the casting manufacturing structure before casting and the volume of the casting after casting, and used as an index of the shape retention of the casting. The volume of the casting production structure before casting and the casting volume after casting were determined by the following formula by measuring the inner diameter of the structure and the diameter of the casting with 10 calipers. From the obtained volume, the volume deformation rate was determined by the following formula, and the dimensional accuracy was evaluated according to the following criteria. The smaller the volume deformation rate, the better the shape retention, which means that a casting close to the designed shape is obtained, and 0% is a casting having the same shape as the designed shape. means.
Volume = (average value of measured inner diameter or diameter / 2) ² × π × 100
Volume deformation rate (%) = [1- (volume of casting after casting / volume of structure for casting production before casting)] × 100
○: Volume deformation rate is 0 to 0.5%
Δ: Volume deformation rate is more than 0.5% to 10% or less ×: Volume deformation rate is more than 10%

[Example 2]
A structure for casting production was obtained in the same manner as in Example 1 except that the inorganic particles were calcium carbonate (“ESCALON # 800” manufactured by Sankyo Seimitsu Co., Ltd.) and the raw material kneading temperature at the time of molding was changed to 160 ° C. . Using this structure, a casting was produced in the same manner as in Example 1, and the volume deformation rate was evaluated in the same manner as in Example 1. The results are shown in Table 1.

Example 3
A structure for casting production was obtained in the same manner as in Example 1 except that the thermoplastic resin was polylactic acid (“LACEA H-280” manufactured by Mitsui Chemicals, Inc.) and the raw material kneading temperature at the time of molding was changed to 150 ° C. It was. Using this structure, a casting was produced in the same manner as in Example 1, and the volume deformation rate was evaluated in the same manner as in Example 1. The results are shown in Table 1.

Example 4
A casting manufacturing structure was obtained in the same manner as in Example 1 except that the composition of the raw materials was changed as shown in Table 1. Using this structure, a casting was produced in the same manner as in Example 1, and the volume deformation rate was evaluated in the same manner as in Example 1. The results are shown in Table 1.

Example 5
A structure for producing castings was obtained in the same manner as in Example 2 except that the blending of raw materials and the kneading temperature were changed as shown in Table 1. Using this structure, a casting was produced in the same manner as in Example 1, and the volume deformation rate was evaluated in the same manner as in Example 1. The results are shown in Table 1.

[Comparative Example 1]
Except that the resole phenolic resin was changed to AV Light Resin SP400 (Asahi Organic Materials Co., Ltd., gel time at 150 ° C. was 1.3 minutes, indicated as “AV Light Resin” in the table). In the same manner as in No. 1, a casting production structure was obtained. Using this structure, a casting was produced in the same manner as in Example 1, and the volume deformation rate was evaluated in the same manner as in Example 1. The results are shown in Table 1.

[Comparative Example 2]
A casting production structure was obtained in the same manner as in Comparative Example 1 except that the thermoplastic resin was polystyrene (“Polystyrene H-9152” manufactured by PS Japan Co., Ltd.) and the raw material kneading temperature at the time of molding was changed to 220 ° C. . Using this structure, a casting was produced in the same manner as in Example 1, and the volume deformation rate was evaluated in the same manner as in Example 1. The results are shown in Table 1.

[Comparative Example 3]
A structure for producing castings was obtained in the same manner as in Example 1 except that the inorganic particles were calcium carbonate (“Escalon # 800” manufactured by Sankyo Flour Milling Co., Ltd.) and the raw material composition was changed as shown in Table 1. Using this structure, a casting was produced in the same manner as in Example 1, and the volume deformation rate was evaluated in the same manner as in Example 1. The results are shown in Table 1.

[Comparative Example 4]
A casting manufacturing structure was obtained in the same manner as in Example 1 except that the composition of the raw materials was changed as shown in Table 1. Using this structure, a casting was produced in the same manner as in Example 1, and the volume deformation rate was evaluated in the same manner as in Example 1. The results are shown in Table 1.

  As shown in Table 1, it can be seen that in Examples 1 to 5, the volume deformation rate is small, the shape retention is good, and a casting having a shape as designed is obtained with high dimensional accuracy. On the other hand, in Comparative Examples 1-4, it turns out that the shape maintenance property of the structure at the time of casting is bad, and the dimensional accuracy of the obtained casting is bad.

It is a perspective view which shows typically the structure for casting manufacture manufactured by the Example and the comparative example. In an Example and a comparative example, it is a figure which shows typically the state which connected the structure for casting manufacture to the ceramic pipe for casting.

Claims (6)

A structure for producing a casting containing inorganic fibers, inorganic particles, a resole phenolic resin having a gel time at 150 ° C. of 1.5 minutes or more, and a thermoplastic resin ,
1 to 50% by weight of inorganic fibers, 5 to 70% by weight of inorganic particles, 1 to 70% by weight of a resol-based phenol resin having a gel time at 150 ° C. of 1.5 minutes or more, and 5 to 60% by weight of a thermoplastic resin contains,
Casting manufacturing structure . The structure for producing a casting according to claim 1, comprising 10 to 60% by weight of inorganic particles . The structure for casting production according to claim 1 or 2, wherein the inorganic fibers are carbon fibers. Inorganic fiber, inorganic particles, resol phenolic resin having a gel time at 150 ° C. of 1.5 minutes or more, and a thermoplastic resin, a method for producing a structure for casting production that is molded after melt-kneading ,
The structure for producing castings is 1 to 50% by weight of inorganic fibers, 5 to 70% by weight of inorganic particles, 1 to 70% by weight of a resole phenolic resin having a gel time at 150 ° C. of 1.5 minutes or more, heat Containing 5 to 60% by weight of a plastic resin,
A method for manufacturing a casting manufacturing structure . The method for producing a structure for producing a casting according to claim 4, wherein the melt kneading temperature is 170 ° C or lower. The manufacturing method of the casting using the structure for casting manufacture of any one of Claims 1-3.

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