Binder composition for casting molds

Abstract

The present invention is a binder composition for casting molds, comprising furfuryl alcohol (component A), bis(hydroxymethyl)furan (component B), a resin (component C), and water (component D), and satisfying the following conditions (1) to (5). Condition (1): The content of component A in the binder composition for casting molds is 30.0% by mass or less; Condition (2): The content of component D in the binder composition for casting molds is 25.0% by mass or less; Condition (3): The content of component B in the binder composition for casting molds is 39.0% by mass or more and 95.0% by mass or less relative to the total content of component B and component C; Condition (4): The nitrogen content in component C is 2.7% by mass or more and 22.0% by mass or less; Condition (5): When the content of component B in the binder composition for casting molds is y and the nitrogen content of component C is x, the following formula (1) is satisfied: 2.97x+15.2≤y(1). According to the present invention, a binder composition containing a small amount of furanol as a single substance and capable of significantly improving the strength of a mold in a low-temperature environment can be provided.

Description

Technical Field

[0001] The present invention relates to a binder composition for casting molds. Background Art

[0002] Generally speaking, acid curing casting molds are manufactured as follows: a binder composition for casting molds containing an acid curing resin and a curing agent composition containing sulfonic acid, sulfuric acid, phosphoric acid, etc. are added to refractory particles such as silica sand, and after these are mixed, the mixed sand obtained is filled into a master mold such as a wooden mold to cure the acid curing resin. Acid curing resins use furan resins, phenol resins, etc., and furan resins use furfuryl alcohol-urea-formaldehyde resins, furfuryl alcohol-formaldehyde resins, furfuryl alcohol-phenol-formaldehyde resins, other known modified furan resins, etc. The manufacturing method of this casting mold can carry out a high degree of freedom molding operation. In addition, the thermal performance of the casting mold is excellent, so high-quality castings can be manufactured, and therefore it is widely used in castings such as casting machinery parts, construction machinery parts, or automotive parts.

[0003] An important condition for mold production is to improve the working environment during mold production (during resin curing). In particular, in order to reduce furfuryl alcohol volatilized during mold production, it is desirable to reduce monomeric furfuryl alcohol in furan resin.

[0004] For example, Japanese Patent Publication No. 2014-501175 discloses that the release of furfuryl alcohol and formaldehyde during kneading and molding can be reduced by using a binder composition containing a low content of monomeric furfuryl alcohol.

[0005] Japanese Patent Application Laid-Open No. 56-61420 discloses a method for producing a phenol-furfuryl alcohol-formaldehyde resin for mold making containing a low content of monomeric furfuryl alcohol, wherein the furfuryl alcohol skeleton is introduced into the resin structure at a high ratio by sufficiently reacting the resin.

[0006] Furthermore, Japanese Patent Application Laid-Open No. 2013-151019 discloses that by using a binder composition containing 5-hydroxymethylfurfural and 2,5-bishydroxymethylfuran instead of furfuryl alcohol, the mold release time can be shortened while maintaining the same usable time, thereby improving mold productivity, and increasing the curing speed and mold strength. Summary of the Invention

[0007] The present invention is a binder composition for casting molds, which contains furfuryl alcohol (component A), bishydroxymethyl furan (component B), resin (component C) and water (component D), and

[0008] The following conditions (1) to (5) must be met.

[0009] Condition (1): The content of the component A in the binder composition for casting molds is 30.0% by mass or less.

[0010] Condition (2): The content of the component D in the binder composition for casting molds is 25.0% by mass or less.

[0011] Condition (3): The content of the component B in the binder composition for casting molds is 39.0% by mass or more and 95.0% by mass or less relative to the total content of the component B and the component C.

[0012] Condition (4): The nitrogen content in the component C is 2.7% by mass or more and 22.0% by mass or less

[0013] Condition (5): When the content of the component B in the binder composition for casting molds is y and the nitrogen content of the component C is x, the following formula (1) is satisfied:

[0014] 2.97x+15.2≤y (1)

[0015] The present invention also provides a composition for casting molds, comprising the above-mentioned binder composition for casting molds and a curing agent composition containing a curing agent for curing the binder composition for casting molds.

[0016] The present invention also provides a composition for a foundry mold comprising refractory particles, the binder composition for foundry mold making, and a curing agent composition containing a curing agent for curing the binder composition for foundry mold making.

[0017] In addition, the present invention is a method for manufacturing a casting mold, which includes: a mixing step of mixing refractory particles, the above-mentioned binder composition for casting mold shaping, and a curing agent composition containing a curing agent for curing the binder composition for casting mold shaping to obtain a casting mold composition; and a curing step of loading the above-mentioned casting mold composition into a mold frame and curing the casting mold composition. DETAILED DESCRIPTION

[0018] Conventionally proposed binder compositions containing a small amount of monomeric furfuryl alcohol have insufficient mold strength, particularly mold strength in a low-temperature environment (eg, 5° C. or less), and thus there is room for improvement.

[0019] The present invention provides a binder composition for mold making, a composition for mold making, a composition for mold making, and a method for producing a mold, which can significantly improve the mold strength in a low-temperature environment and contain a low content of furanol as a single substance.

[0020] The present invention is a binder composition for casting molds, which contains furfuryl alcohol (component A), bishydroxymethyl furan (component B), resin (component C) and water (component D), and

[0021] The following conditions (1) to (5) must be met.

[0022] Condition (1): The content of the component A in the binder composition for casting molds is 30.0% by mass or less.

[0023] Condition (2): The content of the component D in the binder composition for casting molds is 25.0% by mass or less.

[0024] Condition (3): The content of the component B in the binder composition for casting molds is 39.0% by mass or more and 95.0% by mass or less relative to the total content of the component B and the component C.

[0025] Condition (4): The nitrogen content in the component C is 2.7% by mass or more and 22.0% by mass or less

[0026] Condition (5): When the content of the component B in the binder composition for casting molds is y and the nitrogen content of the component C is x, the following formula (1) is satisfied:

[0027] 2.97x+15.2≤y (1)

[0028] The present invention also provides a composition for casting molds, comprising the above-mentioned binder composition for casting molds and a curing agent composition containing a curing agent for curing the binder composition for casting molds.

[0029] The present invention also provides a composition for a foundry mold comprising refractory particles, the binder composition for foundry mold making, and a curing agent composition containing a curing agent for curing the binder composition for foundry mold making.

[0030] In addition, the present invention is a method for manufacturing a casting mold, which includes: a mixing step of mixing refractory particles, the above-mentioned binder composition for casting mold shaping, and a curing agent composition containing a curing agent for curing the binder composition for casting mold shaping to obtain a casting mold composition; and a curing step of loading the above-mentioned casting mold composition into a mold frame and curing the casting mold composition.

[0031] The present invention provides a binder composition for mold making, a composition for mold making, a composition for mold making, and a method for producing a mold, which can significantly improve mold strength in a low-temperature environment and contain a low content of furanol as a single substance.

[0032] Hereinafter, one embodiment of the present invention will be described.

[0033] <Binder composition for mold making>

[0034] The binder composition for casting molds of this embodiment (hereinafter also referred to simply as the binder composition) contains furfuryl alcohol (component A), bishydroxymethylfuran (component B), a resin (component C) and water (component D), and satisfies the following conditions (1) to (5).

[0035] Condition (1): The content of the component A in the binder composition for casting molds is 30.0% by mass or less.

[0036] Condition (2): The content of the component D in the binder composition for casting molds is 25.0% by mass or less.

[0037] Condition (3): The content of the component B in the binder composition for casting molds is 39.0% by mass or more and 95.0% by mass or less relative to the total content of the component B and the component C.

[0038] Condition (4): The nitrogen content in the component C is 2.7% by mass or more and 22.0% by mass or less

[0039] Condition (5): When the content of the component B in the binder composition for casting molds is y and the nitrogen content of the component C is x, the following formula (1) is satisfied:

[0040] 2.97x+15.2≤y (1)

[0041] The binder composition can significantly improve mold strength in a low-temperature environment and has a low content of furanol as a single substance. The reason why the binder composition exhibits such an effect is still unclear, but it is considered as follows.

[0042] Compared with the resin (component C), bishydroxymethylfuran (component B) has excellent reactivity with furfuryl alcohol (component A) and reduces the viscosity of the above-mentioned binder composition. If the content of bishydroxymethylfuran (component B) increases, the reactivity increases, the viscosity of the binder composition also decreases, and the compatibility with refractory particles also increases, so the mold strength increases. On the other hand, since the melting point of bishydroxymethylfuran (component B) is high, if the content increases, the storage stability deteriorates (condition (3)). In addition, if the nitrogen content in the resin increases, the cross-linking reaction is promoted and the mold strength improves. On the other hand, if the nitrogen content in the resin increases, the viscosity of the binder composition becomes higher, the compatibility with refractory particles deteriorates, and the strength decreases (condition (4)). Therefore, it is believed that as the nitrogen content in the resin increases, the content of bishydroxymethylfuran (component B) relative to the total content of bishydroxymethylfuran (component B) and resin (component C) is increased to reduce the viscosity, thereby improving the mold strength (condition (5)).

[0043] [Furyl alcohol (ingredient A)]

[0044] For the viewpoint based on improving working environment, the content of the above-mentioned component A in above-mentioned binder composition is below 30.0 mass %, preferably below 25.0 mass %, more preferably below 20.0 mass %, further preferably below 15.0 mass %.For the viewpoint based on improving mold strength, the content of the above-mentioned component A in above-mentioned binder composition is preferably more than 0 mass %, more preferably more than 5.0 mass %, further preferably more than 10.0 mass %, more further preferably more than 15.0 mass %, more further preferably more than 20.0 mass %.It should be noted that the content of component A can be measured by the method described in example.

[0045] [Bis(hydroxymethyl)furan (ingredient B)]

[0046] From the viewpoint of reducing the content of monomeric furfuryl alcohol and significantly improving the mold strength in a low-temperature environment, the component B is preferably 2,5-bishydroxymethylfuran and / or 3,4-bishydroxymethylfuran, and more preferably 2,5-bishydroxymethylfuran.

[0047] Based on the viewpoint of reducing the content of monomeric furan methanol and greatly improving the mold strength under low temperature environment, the content of the above-mentioned component B in the above-mentioned binder composition is preferably 18.0 mass % or more, more preferably 20.0 mass % or more, further preferably 21.0 mass % or more, further preferably 22.0 mass % or more, further preferably 39.0 mass % or more, further preferably 51.0 mass % or more, further preferably 63.0 mass % or more. Based on the viewpoint of improving storage stability, the content of the above-mentioned component B in the above-mentioned binder composition is preferably 70.0 mass % or less, more preferably 68.0 mass % or less, further preferably 65.0 mass % or less, further preferably 63.0 mass % or less. It should be noted that the content of component B can be measured by the method described in the examples.

[0048] [Resin (Component C)]

[0049] The above-mentioned component C can be used without particular limitation as long as it is a resin used as a binder for casting molds. As the resin used as a binder for casting molds, an acid-curable resin can be exemplified, and as the acid-curable resin, one or more selected from furan resins, condensates of melamine and aldehydes, condensates of urea and aldehydes, and condensates of ethylene urea and aldehydes can be exemplified. From the perspective of reducing the content of monomeric furan carbinol and significantly improving the strength of the casting mold in a low-temperature environment, the above-mentioned component C preferably contains a furan resin. It should be noted that the above-mentioned component C does not include furan carbinol.

[0050] The furan resin is obtained by polymerizing a monomer composition containing furan carbinol, and any resin can be used without particular limitation as long as it can be used as a binder for mold forming. From the viewpoint of reducing the content of monomeric furan carbinol and significantly improving the casting strength under low temperature environment, the above-mentioned furan resin preferably contains one or more selected from the following condensates, and one or more selected from two or more co-condensates selected from them: condensates of furan carbinol and urea; condensates of furan carbinol and melamine; condensates of furan carbinol and ethylene urea; condensates of furan carbinol, urea and aldehydes (urea-modified furan resin); condensates of furan carbinol, melamine and aldehydes; condensates of furan carbinol, ethylene urea and aldehydes; furan carbinol condensates; condensates of furan carbinol and aldehydes; and condensates of furan carbinol, phenols and aldehydes. The above-mentioned furan resin more preferably contains one or more selected from urea-modified furan resins, furan carbinol condensates and condensates of furan carbinol and aldehydes, and one or more selected from two or more co-condensates selected from them.

[0051] Examples of the aldehydes include formaldehyde, acetaldehyde, glyoxal, furfural, terephthalaldehyde, and hydroxymethylfurfural. One or more of these may be used as appropriate. Formaldehyde is preferably used from the perspective of increasing mold strength, while furfural, terephthalaldehyde, and hydroxymethylfurfural are preferably used from the perspective of reducing formaldehyde generation during molding.

[0052] Examples of the phenols include phenol, cresol, resorcinol, bisphenol A, bisphenol C, bisphenol E, and bisphenol F, and one or more of these may be used.

[0053] The furan resin can be produced by a known method. For example, if the furan resin is a urea-modified furan resin, the urea-modified furan resin can be obtained by reacting 0.6 to 30.0 parts by mass of urea and 0.4 to 50.0 parts by mass of paraformaldehyde with 100.0 parts by mass of furfuryl alcohol.

[0054] From the perspective of reducing the content of monomeric furan carbinol and significantly improving the mold strength in a low-temperature environment, the total content of one or more selected from the above-mentioned urea-modified furan resin, furan carbinol condensate, and condensate of furan carbinol and aldehydes, and one or more selected from co-condensates of two or more selected therefrom, in the above-mentioned furan resin is preferably 90% by mass or more, more preferably 95% by mass or more, even more preferably 98% by mass or more, even more preferably substantially 100% by mass, and even more preferably 100% by mass. It should be noted that in this specification, "substantially" refers to an amount that may contain impurities.

[0055] From the viewpoint of reducing the content of monomeric furan carbinol and significantly improving the casting strength in a low-temperature environment, the content of the furan resin in the above-mentioned component C is preferably 80% by mass or more, more preferably 90% by mass or more, further preferably 95% by mass or more, further preferably 98% by mass or more, further preferably substantially 100% by mass, and even more preferably 100% by mass.

[0056] For the viewpoint of the mold strength under low temperature environment that is significantly improved based on the cross-linking density of improving resin, the nitrogen content (in this manual, nitrogen content refers to the content of nitrogen atoms) in above-mentioned composition C is more than 2.7 mass %, preferably more than 2.8 mass %, more preferably more than 3.7 mass %, further preferably more than 4.6 mass %. Based on the good kneading property of maintenance and refractory aggregate, for the viewpoint that mold strength is suppressed to reduce, the nitrogen content in above-mentioned composition C is below 22.0 mass %, preferably below 21.0 mass %, more preferably below 17.0 mass %, further preferably below 13.9 mass %. It should be noted that the nitrogen content in composition C can be measured by the method described in writing in embodiment.

[0057] From the perspective of increasing the crosslinking density of the resin and significantly improving the mold strength in a low-temperature environment, the content of the component C in the binder composition is preferably 5.0% by mass or more, more preferably 6.0% by mass or more, and even more preferably 7.0% by mass or more. From the perspective of maintaining good miscibility with refractory aggregates and suppressing a decrease in mold strength, the content of the component C in the binder composition is preferably 45.0% by mass or less, more preferably 43.0% by mass or less, and even more preferably 42.0% by mass or less.

[0058] For the viewpoint of significantly improving the mold strength under low temperature environment based on improving the cross-linking density of resin, the nitrogen content in the above-mentioned binder composition is preferably more than 0.1 mass %, more preferably more than 0.2 mass %. Based on maintaining the good kneading property with refractory aggregate, for the viewpoint of suppressing the reduction of mold strength, the nitrogen content in the above-mentioned binder composition is preferably below 3.5 mass %, more preferably below 3.2 mass %, further preferably below 3.0 mass %. It should be noted that the nitrogen content in the binder composition can be measured by the method described in the examples.

[0059] From the perspective of increasing the crosslinking density of the resin and significantly improving the mold strength in a low-temperature environment, the content of the component B in the binder composition is 39.0% by mass or more, preferably 51.0% by mass or more, and more preferably 63.0% by mass or more relative to the total content of the component B and the component C. From the perspective of improving storage stability, the content of the component B in the binder composition is 95.0% by mass or less, preferably 92.0% by mass or less, more preferably 90.0% by mass or less, and even more preferably 78.0% by mass or less relative to the total content of the component B and the component C.

[0060] When the content of the component B in the binder composition is y and the nitrogen content of the component C is x, the binder composition satisfies the above formula (1) from the viewpoint of reducing the content of monomeric furanol and significantly improving the mold strength in a low-temperature environment.

[0061] In the above-mentioned binder composition, from the viewpoint of reducing the content of monomeric furanol and significantly improving the mold strength in a low-temperature environment, it is preferred that the content of the above-mentioned component B in the above-mentioned binder composition is 39.0 to 95.0 mass % relative to the total content of the above-mentioned component B and the above-mentioned component C, and the nitrogen content in the above-mentioned component C is 2.7 to 22.0 mass %, and the above-mentioned formula (1) is satisfied.

[0062] In the above-mentioned binder composition, from the viewpoint of reducing the content of monomeric furanol and significantly improving the mold strength in a low-temperature environment, it is preferred that the content of the above-mentioned component B in the above-mentioned binder composition is 51.0 to 95.0 mass % relative to the total content of the above-mentioned component B and the above-mentioned component C, and the nitrogen content in the above-mentioned component C is 2.7 to 22.0 mass %, and the above-mentioned formula (1) is satisfied.

[0063] In the above-mentioned binder composition, from the viewpoint of reducing the content of monomeric furanol and significantly improving the mold strength in a low-temperature environment, it is more preferred that the content of the above-mentioned component B in the above-mentioned binder composition is 63.0 to 95.0 mass % relative to the total content of the above-mentioned component B and the above-mentioned component C, and the nitrogen content in the above-mentioned component C is 2.7 to 22.0 mass %, and the above-mentioned formula (1) is satisfied.

[0064] In the above-mentioned binder composition, from the viewpoint of reducing the content of monomeric furanol and significantly improving the mold strength in a low-temperature environment, it is further preferred that the content of the above-mentioned component B in the above-mentioned binder composition is 63.0 to 95.0 mass % relative to the total content of the above-mentioned component B and the above-mentioned component C, and the nitrogen content in the above-mentioned component C is 3.7 to 17.0 mass %, and the above-mentioned formula (1) is satisfied.

[0065] In the above-mentioned binder composition, from the viewpoint of reducing the content of monomeric furanol and significantly improving the mold strength in a low-temperature environment, it is further preferred that the content of the above-mentioned component B in the above-mentioned binder composition is 63.0 to 95.0 mass % relative to the total content of the above-mentioned component B and the above-mentioned component C, and the nitrogen content in the above-mentioned component C is 4.6 to 13.9 mass %, and satisfies the following formula (2).

[0066] 1.32x+57.4≤y (2)

[0067] In the above-mentioned adhesive composition, from the viewpoint of improving storage stability, it is further preferred that the content of the above-mentioned component B in the above-mentioned adhesive composition is 63.0-78.0 mass % relative to the total content of the above-mentioned component B and the above-mentioned component C, and the nitrogen content in the above-mentioned component C is 4.6-13.9 mass %, and the above-mentioned formula (2) is satisfied.

[0068] [Water (ingredient D)]

[0069] For the viewpoint based on improving mold strength, the content of the above-mentioned component D in the above-mentioned binder composition is 25.0 mass % or less, preferably 20.0 mass % or less. For the viewpoint based on regulating the viscosity of the above-mentioned binder composition, the content of the above-mentioned component D in the above-mentioned binder composition is preferably 5.0 mass % or more, more preferably 8.0 mass % or more, further preferably 10.0 mass % or more. It should be noted that the content of component D can be measured by the method described in the examples.

[0070] [Curing accelerator]

[0071] From the perspective of improving mold strength, the binder composition may also contain a curing accelerator. From the perspective of improving mold strength, the curing accelerator is preferably one or more selected from phenol derivatives, aromatic dialdehydes, and tannins.

[0072] Examples of the phenol derivatives include resorcinol, cresol, hydroquinone, phloroglucinol, and methylene bisphenol. From the perspective of improving mold strength, the content of the phenol derivative in the binder composition is preferably 1 to 25% by mass, more preferably 2 to 15% by mass, and even more preferably 3 to 10% by mass.

[0073] Examples of the aromatic dialdehyde include terephthalaldehyde, o-phthalaldehyde, and isophthalaldehyde, as well as their derivatives. These derivatives are compounds having substituents such as alkyl groups on the aromatic ring of an aromatic compound having two formyl groups as its basic skeleton. To ensure that the aromatic dialdehyde is fully soluble in the furan resin and to suppress the odor of the aromatic dialdehyde itself, the content of the aromatic dialdehyde in the adhesive composition is preferably 0.1 to 15% by mass, more preferably 0.5 to 10% by mass, and even more preferably 1 to 5% by mass.

[0074] Examples of the tannins include condensed tannins and hydrolyzable tannins. Examples of these condensed and hydrolyzable tannins include tannins with a pyrogallol skeleton and a resorcinol skeleton. In addition, extracts from bark containing these tannins, or extracts from natural materials such as plant leaves, fruits, seeds, and parasitic galls, may also be added. To increase the curing speed and mold strength, the tannin content in the adhesive composition is preferably 0.2 to 10% by mass, more preferably 1.0 to 7% by mass, and even more preferably 1.9 to 5% by mass.

[0075] From the perspective of workability during production of the mold composition and mold production, the viscosity of the binder composition at 25°C is preferably 70 mPa·s or less, more preferably 50 mPa·s or less. The viscosity of the binder composition at 25°C can be measured by the method described in the Examples.

[0076] The adhesive composition may also include additives such as a silane coupling agent. For example, if the adhesive composition includes a silane coupling agent, the final strength of the obtained mold can be further improved, so it is preferred. As the silane coupling agent, aminosilanes such as N-β-(aminoethyl)-γ-aminopropylmethyldimethoxysilane, N-β-(aminoethyl)-γ-aminopropyltrimethoxysilane, N-β-(aminoethyl)-γ-aminopropyltriethoxysilane, and 3-aminopropyltrimethoxysilane can be used; epoxysilanes such as 3-glycidoxypropyltrimethoxysilane, 3-glycidoxypropyltriethoxysilane, 3-glycidoxypropylmethyldimethoxysilane, 3-glycidoxypropylmethyldiethoxysilane, and 3-glycidoxypropyltriethoxysilane can be used; ureasilanes, mercaptosilanes, sulfosilanes, methacryloxysilanes, and acryloxysilanes can be used. Preferred are aminosilanes, epoxysilanes, and ureidosilanes. More preferred are aminosilanes and epoxysilanes. Among aminosilanes, N-β-(aminoethyl)-γ-aminopropylmethyldimethoxysilane is preferred. Among epoxysilanes, 3-glycidoxypropylmethyldimethoxysilane is preferred.

[0077] From the perspective of improving mold strength, the content of the silane coupling agent in the adhesive composition is preferably 0.01% by mass or more, more preferably 0.05% by mass or more. From the same perspective, the content of the silane coupling agent in the adhesive composition is preferably 5% by mass or less, more preferably 3% by mass or less, further preferably 1% by mass or less, and further preferably 0.5% by mass or less.

[0078] The binder composition for casting molds according to this embodiment is suitable for forming self-consolidating casting molds. A self-consolidating casting mold is one in which, when the binder composition and a curing agent are mixed with sand, a polymerization reaction proceeds over time, causing the mold to solidify. The temperature of the sand used in this process is in the range of -20°C to 50°C, preferably 0°C to 40°C. By adding a curing agent in an amount appropriate for the sand at this temperature, the casting mold can be properly solidified.

[0079] <Molding Composition>

[0080] The casting mold composition of this embodiment includes the binder composition described above and a curing agent composition containing a curing agent for curing the binder composition for casting molds. The casting mold composition of this embodiment has the same effects as the binder composition described above.

[0081] [Curing agent composition]

[0082] The curing agent composition can be used without particular limitation as long as it contains a curing agent that cures the binder composition. Examples of the curing agent include acidic curing agents, and one or more of the following curing agents, such as sulfonic acid compounds such as xylenesulfonic acid (especially m-xylenesulfonic acid), toluenesulfonic acid (especially p-toluenesulfonic acid), and methanesulfonic acid; phosphoric acid compounds such as phosphoric acid and acidic phosphates; and sulfuric acid. From the perspective of operability, these compounds are preferably aqueous solutions. Furthermore, the curing agent composition may contain one or more solvents selected from alcohols, ether alcohols, and esters, and carboxylic acids.

[0083] The content of the solvent in the curing agent composition can be appropriately adjusted to obtain the desired reaction rate and mold strength according to the temperature of the operating environment or the temperature of the refractory particles. Generally, from the perspective of dissolving the curing agent composition, the content is preferably 5% by mass or more, more preferably 10% by mass or more, and even more preferably 20% by mass or more. From the perspective of improving mold strength, the content of the solvent in the curing agent composition is preferably 90% by mass or less, more preferably 80% by mass or less, and even more preferably 70% by mass or less.

[0084] From the perspective of improving mold strength, the content of the curing agent in the curing agent composition is preferably 10% by mass or more, more preferably 20% by mass or more, and even more preferably 30% by mass or more. From the perspective of dissolving the curing agent composition, the content of the curing agent in the curing agent composition is preferably 95% by mass or less, more preferably 90% by mass or less, and even more preferably 80% by mass or less.

[0085] Regarding the mass ratio of the above-mentioned adhesive composition to the above-mentioned curing agent, based on the viewpoint of increasing the curing speed and improving the mold strength, the above-mentioned curing agent is preferably 10 to 60 parts by mass, more preferably 10 to 40 parts by mass, and further preferably 10 to 30 parts by mass relative to 100 parts by mass of the above-mentioned adhesive composition.

[0086] [Mold composition]

[0087] The mold composition of this embodiment contains refractory particles, the binder composition, and the curing agent composition. The mold composition of this embodiment has the same effects as the binder composition.

[0088] [Refractory particles]

[0089] As the refractory particles, one or more of conventionally known refractory particles such as silica sand, chrome sand, zircon sand, olivine sand, alumina sand, mullite sand, and synthetic mullite sand may be used. Furthermore, particles obtained by recycling or regenerating used refractory particles may also be used. Among these, silica sand is preferably included.

[0090] In the above-mentioned casting mold composition, the mass ratio of the above-mentioned refractory particles, the above-mentioned binder composition and the above-mentioned curing agent can be appropriately set. From the viewpoint of increasing the curing speed and improving the casting mold strength, the above-mentioned binder composition is preferably in the range of 0.5 to 1.5 mass parts, and the above-mentioned curing agent is preferably in the range of 0.07 to 1 mass part relative to 100 mass parts of the above-mentioned refractory particles.

[0091] <Mold Manufacturing Method>

[0092] The method for manufacturing a casting mold according to this embodiment includes a mixing step of mixing refractory particles, the binder composition, and the curing agent composition to obtain a casting mold composition; and a curing step of placing the casting mold composition into a mold frame and curing the casting mold composition. This casting mold manufacturing method achieves the same effects as the binder composition described above.

[0093] In the above-mentioned mixing process, the order of adding and mixing the above-mentioned binder composition and the above-mentioned curing agent composition and refractory particles is not particularly limited, after the above-mentioned binder composition can be mixed with the above-mentioned curing agent composition and manufacture casting mold composition, the casting mold composition is mixed with refractory particles, and the above-mentioned binder composition, the above-mentioned curing agent composition and refractory particles can also be added and mixed respectively, but based on the viewpoint of storage stability and the productivity of casting mold, it is preferred that the above-mentioned binder composition, the above-mentioned curing agent composition and refractory particles are mixed and obtain casting mold composition. In addition, based on the viewpoint of improving casting mold strength, it is preferred to add curing agent composition to refractory particles and mix, then add binder composition and mix. In addition, when using two or more curing agent compositions, each curing agent composition can be mixed and added, or each curing agent composition can be added respectively.

[0094] In the mixing step, a known general method can be used to mix the raw materials. Examples of the method include a method of adding and kneading the raw materials using a batch mixer and a method of supplying and kneading the raw materials using a continuous mixer.

[0095] In the method for manufacturing a casting mold according to the present embodiment, the casting mold can be manufactured by utilizing the conventional casting mold manufacturing process as it is, except for the mixing step.

[0096] Regarding the above embodiments, the present invention further discloses the following compositions, manufacturing methods or uses.

[0097] <1> A binder composition for casting molds, comprising furfuryl alcohol (component A), bis(hydroxymethyl)furan (component B), a resin (component C), and water (component D), and

[0098] The following conditions (1) to (5) must be met.

[0099] Condition (1): The content of the component A in the binder composition for casting molds is 30.0% by mass or less.

[0100] Condition (2): The content of the component D in the binder composition for casting molds is 25.0% by mass or less.

[0101] Condition (3): The content of the component B in the binder composition for casting molds is 39.0% by mass or more and 95.0% by mass or less relative to the total content of the component B and the component C.

[0102] Condition (4): The nitrogen content in the component C is 2.7% by mass or more and 22.0% by mass or less

[0103] Condition (5): When the content of the component B in the binder composition for casting molds is y and the nitrogen content of the component C is x, the following formula (1) is satisfied:

[0104] 2.97x+15.2≤y (1)

[0105] <2> The binder composition for casting molds according to <1>, comprising furfuryl alcohol (component A), bishydroxymethylfuran (component B), a resin (component C) and water (component D), and

[0106] The following conditions (1) to (5) must be met.

[0107] Condition (1): The content of the component A in the binder composition for casting molds is 5.0% by mass or more and 30.0% by mass or less.

[0108] Condition (2): The content of the component D in the binder composition for casting molds is 5.0% by mass or more and 25.0% by mass or less.

[0109] Condition (3): The content of the component B in the binder composition for casting molds is 39.0% by mass or more and 95.0% by mass or less relative to the total content of the component B and the component C.

[0110] Condition (4): The nitrogen content in the component C is 2.7% by mass or more and 22.0% by mass or less

[0111] Condition (5): When the content of the component B in the binder composition for casting molds is y and the nitrogen content of the component C is x, the following formula (1) is satisfied:

[0112] 2.97x+15.2≤y (1)

[0113] <3> The binder composition for casting molds according to <1> or <2>, wherein the content of Component A is 10.0% by mass or more and 30.0% by mass or less.

[0114] <4> The binder composition for casting molds according to any one of <1> to <3>, wherein the content of the component A is 15.0% by mass or more and 30.0% by mass or less.

[0115] <5> The binder composition for casting molds according to any one of <1> to <4>, wherein the content of the component D is 8.0% by mass or more and 25.0% by mass or less.

[0116] <6> The binder composition for casting molds according to any one of <1> to <5>, wherein the content of the component D is 10.0% by mass or more and 20.0% by mass or less.

[0117] <7> The binder composition for casting molds according to any one of <1> to <6>, which satisfies the following conditions (3) to (5).

[0118] Condition (3): The content of the component B in the binder composition for casting molds is 51.0% by mass or more and 95.0% by mass or less relative to the total content of the component B and the component C.

[0119] Condition (4): The nitrogen content in the component C is 2.7% by mass or more and 22.0% by mass or less

[0120] Condition (5): When the content of the component B in the binder composition for casting molds is y and the nitrogen content of the component C is x, the following formula (1) is satisfied:

[0121] 2.97x+15.2≤y (1)

[0122] <8> The binder composition for casting molds according to any one of <1> to <7>, which satisfies the following conditions (3) to (5).

[0123] Condition (3): The content of the component B in the binder composition for casting molds is 63.0% by mass or more and 95.0% by mass or less relative to the total content of the component B and the component C.

[0124] Condition (4): The nitrogen content in the component C is 2.7% by mass or more and 22.0% by mass or less

[0125] Condition (5): When the content of the component B in the binder composition for casting molds is y and the nitrogen content of the component C is x, the following formula (1) is satisfied:

[0126] 2.97x+15.2≤y (1)

[0127] <9> The binder composition for casting molds according to any one of <1> to <8>, wherein the component C contains a furan resin, and the content of the furan resin in the component C is 80% by mass or more.

[0128] <10> The binder composition for casting molds according to any one of <1> to <9>, wherein the component C contains a furan resin, and the content of the furan resin in the component C is 90% by mass or more.

[0129] <11> The binder composition for casting molds according to any one of <1> to <10>, wherein the component C contains a furan resin, and the content of the furan resin in the component C is 95% by mass or more.

[0130] <12> The binder composition for casting molds according to any one of <1> to <11>, wherein the component C contains a furan resin, and the content of the furan resin in the component C is 98% by mass or more.

[0131] <13> The binder composition for casting molds according to any one of <1> to <12>, wherein the component C contains a furan resin, and the content of the furan resin in the component C is substantially 100% by mass.

[0132] <14> The binder composition for casting molds as described in any one of <9> to <13>, wherein the furan resin contains one or more selected from urea-modified furan resins, furan methanol condensates, and condensates of furan methanol and aldehydes, and one or more selected from co-condensates of two or more selected therefrom.

[0133] <15> The binder composition for casting molds as described in <14>, wherein the total content of one or more selected from the above-mentioned urea-modified furan resin, furan methanol condensate and condensate of furan methanol and aldehydes, and one or more selected from co-condensates of two or more selected therefrom in the above-mentioned furan resin is 90% by mass or more.

[0134] <16> The binder composition for casting molds as described in <14> or <15>, wherein the total content of one or more selected from the above-mentioned urea-modified furan resin, furan methanol condensate and condensate of furan methanol and aldehydes, and one or more selected from co-condensates of two or more selected therefrom in the above-mentioned furan resin is 95% by mass or more.

[0135] <17> The binder composition for casting molds as described in any one of <14> to <16>, wherein the total content of one or more selected from the above-mentioned urea-modified furan resin, furan methanol condensate and condensate of furan methanol and aldehydes, and one or more selected from co-condensates of two or more selected therefrom in the above-mentioned furan resin is 98% by mass or more.

[0136] <18> The binder composition for casting molds as described in any one of <14> to <17>, wherein the total content of one or more selected from the above-mentioned urea-modified furan resin, furan methanol condensate and condensate of furan methanol and aldehydes, and one or more selected from co-condensates of two or more selected therefrom in the above-mentioned furan resin is substantially 100% by mass.

[0137] <19> A casting mold composition comprising the casting mold binder composition according to any one of <1> to <18> and a curing agent composition containing a curing agent for curing the casting mold binder composition.

[0138] <20> A casting mold composition comprising refractory particles, the casting mold binder composition according to any one of <1> to <18>, and a curing agent composition containing a curing agent that cures the casting mold binder composition.

[0139] <21> The casting composition according to <20>, wherein the binder composition is present in an amount of 0.5 to 1.5 parts by mass and the curing agent is present in an amount of 0.07 to 1 part by mass per 100 parts by mass of the refractory particles.

[0140] <22> A method for manufacturing a casting mold, comprising: a mixing step of mixing refractory particles, a binder composition for casting molds as described in any one of <1> to <18>, and a curing agent composition containing a curing agent for curing the binder composition for casting molds to obtain a casting mold composition; and a curing step of placing the casting mold composition into a mold frame and curing the casting mold composition.

[0141] Example

[0142] Hereinafter, embodiments and the like that specifically illustrate the present invention will be described.

[0143] <Measurement methods of physical properties>

[0144] [Water content]

[0145] The measurement was performed using an automatic moisture meter (manufactured by Hiranuma Sangyo Co., Ltd., AQV-2200A) in accordance with the Karl Fischer method specified in JIS K 0068.

[0146] [Content of furanol and bis(hydroxymethylfuran)]

[0147] The measurement was performed by gas chromatography analysis under the following conditions using a gas chromatograph (GC-2014S manufactured by Shimadzu Corporation).

[0148] Standard curve: prepared using furanol and bis(hydroxymethylfuran).

[0149] Internal standard solution: 1,6-hexanediol

[0150] Column: PEG-20M Chromosorb WAW DMCS 60 / 80 mesh (manufactured by GL Science)

[0151] Column temperature: 80~200℃ (8℃ / min)

[0152] Injection temperature: 210℃

[0153] Detector temperature: 250°C Carrier gas: 50 mL / min (He)

[0154] [Nitrogen content]

[0155] The measurement was performed based on the Kjeldahl method shown in JIS K 6451-2.

[0156] [Viscosity]

[0157] The viscosity was measured using an E-type viscometer (RE-80R, manufactured by Toki Sangyo Co., Ltd.) at 25° C. using a standard rotor (cone angle: 1°34′, cone radius: 24 mm) at a rotation speed of 100 rpm.

[0158] <Resin Manufacturing Method>

[0159] [Urea modified furan resin]

[0160] Into a three-necked flask, 609 g of furfuryl alcohol, 0.7 g of a 25% by mass sodium hydroxide aqueous solution, 188 g of 92% by mass paraformaldehyde, and 140 g of urea were added and reacted at 100°C for 45 minutes under normal pressure. Then, 1.4 g of glutaric acid was added and the mixture was further reacted at 100°C for 45 minutes. Then, 52 g of urea was added and the mixture was reacted at 70°C for 30 minutes. After the reaction, the pH was adjusted to 10 with a 25% by mass sodium hydroxide aqueous solution. The obtained composition was subjected to reduced pressure distillation at 110°C and an internal pressure of 5 mmHg using a rotary evaporator to remove water and a portion of the furfuryl alcohol. The composition of the obtained reactant was 71.9% by mass of urea-modified furan resin and 28.1% by mass of furfuryl alcohol. In addition, the nitrogen content of the obtained reactant was 14.5% by mass, and the nitrogen content of the urea-modified furan resin was 20.2% by mass.

[0161] [Furan methanol condensate]

[0162] 492 g of furancarbinol and 8 g of glutaric acid were placed in a three-necked flask and reacted at 100°C under normal pressure for 5 hours. The pH was then adjusted to 10 using a 25% by mass aqueous sodium hydroxide solution. The resulting composition was subjected to reduced pressure distillation using a rotary evaporator at 110°C and an internal pressure of 5 mmHg to remove water and a portion of the furancarbinol. The resulting reaction product contained 79.0% by mass of the furancarbinol condensate and 21.0% by mass of the furancarbinol.

[0163] [2,5-Bis(hydroxymethyl)furan(BHMF)]

[0164] 615 g of furfuryl alcohol, 205 g of 92% by mass paraformaldehyde, and 41 g of glutaric acid were added to a three-necked flask and reacted at 100°C under normal pressure for 3 hours. Thereafter, the pH value was adjusted to 10 with a 48% aqueous sodium hydroxide solution. The obtained composition was subjected to reduced pressure distillation at 110°C and an internal pressure of 5 mmHg using a rotary evaporator to remove furfuryl alcohol and water. The obtained residue was completely dissolved in chloroform heated to 40°C and then cooled at 5°C to obtain BHMF crystals. The same operation was then repeated twice. The purity of the obtained crystals was 100% by mass.

[0165] <Production Example of Adhesive Composition>

[0166] [Production Example 1]

[0167] Resin a was obtained according to the procedure described in paragraph 0055 of "Production of Condensate 1" of JP-A-2013-151019. The unreacted furfuryl alcohol and water content of Resin a were measured. Based on the measurement results, an adhesive composition of Production Example 1 was prepared using Resin a, furfuryl alcohol, water, and a silane coupling agent to achieve a furfuryl alcohol content of 50% by mass, a water content of 10% by mass, and a silane coupling agent content of 0.15% by mass.

[0168] [Production Example 2]

[0169] The adhesive composition of Production Example 2 was prepared using the resin a, furfuryl alcohol, water, and a silane coupling agent so that the furfuryl alcohol content was 50 mass %, the water content was 20 mass %, and the silane coupling agent content was 0.15 mass %.

[0170] [Production Example 3]

[0171] In a three-necked flask, 587 g of furfuryl alcohol, 1.0 g of a 25% by mass aqueous sodium hydroxide solution, 159 g of 92% by mass paraformaldehyde, and 29 g of glutaric acid were added and reacted at 125°C under normal pressure for 3 hours. The mixture was then cooled to 90°C, 35 g of urea was added, and the temperature was raised to 105°C and allowed to react at the same temperature for 2 hours. After the reaction, the mixture was cooled to 75°C, 7 g of urea was added, and the mixture was allowed to react at the same temperature for 20 minutes to obtain Resin B. Resin B contained 20.0% by mass of furfuryl alcohol, 29.5% by mass of BHMF, 6.8% by mass of water, and 2.4% by mass of nitrogen. 1.5 g of a silane coupling agent, 36 g of furfuryl alcohol, and 145 g of water were added to Resin B and mixed to obtain the adhesive composition of Production Example 3. The binder composition of Production Example 3 contained 20.0 mass % furanol, 24.1 mass % BHMF, 32.9 mass % furan resin, 20.0 mass % water, and 6.0 mass % nitrogen in the furan resin.

[0172] [Production Example 4]

[0173] In a three-necked flask, 588 g of furfuryl alcohol, 1.0 g of a 25% by mass sodium hydroxide aqueous solution, 159 g of 92% by mass paraformaldehyde, and 29 g of benzoic acid were added and reacted at 125°C under normal pressure for 2 hours. The mixture was then cooled to 90°C, 10 g of 92% by mass paraformaldehyde and 50 g of urea were added, and the temperature was raised to 105°C, followed by reaction at the same temperature for 2 hours. After the reaction, the mixture was cooled to 75°C, 11 g of urea was added, and the mixture was reacted at the same temperature for 20 minutes to obtain Resin C. Resin C contained 22.0% by mass of furfuryl alcohol, 26.4% by mass of BHMF, 7.4% by mass of water, and 3.3% by mass of nitrogen. To Resin C, 1.5 g of a silane coupling agent, 13 g of furfuryl alcohol, and 138 g of water were added and mixed to obtain the adhesive composition of Production Example 4. The binder composition of Production Example 4 contained 20.0 mass % furanol, 22.4 mass % BHMF, 34.6 mass % furan resin, 20.0 mass % water, and 8.1 mass % nitrogen in the furan resin.

[0174] [Production Example 5]

[0175] 359 g of the above-mentioned resin c, 121 g of furfuryl alcohol, 173 g of water, 345 g of BHMF, and 1.5 g of a silane coupling agent were added to a three-necked flask and stirred at 40° C. for 30 minutes to obtain an adhesive composition of Production Example 5. The adhesive composition of Production Example 5 had a furfuryl alcohol content of 20.0% by mass, a BHMF content of 44.0% by mass, a furan resin content of 14.7% by mass, a water content of 20.0% by mass, and a nitrogen content in the furan resin of 8.1% by mass.

[0176] [Production Example 6]

[0177] 569 g of furfuryl alcohol, 0.9 g of a 25% by mass aqueous sodium hydroxide solution, 154 g of 92% by mass paraformaldehyde, and 28 g of glutaric acid were placed in a three-necked flask and reacted at 125°C for 3 hours under normal pressure. The mixture was then cooled to 90°C, 58 g of ethylene urea was added, and the temperature was raised to 105°C and allowed to react at the same temperature for 3 hours. After the reaction, the mixture was cooled to 75°C, 8 g of urea was added, and the mixture was allowed to react at the same temperature for 20 minutes to obtain Resin d. Resin d contained 20.6% by mass of furfuryl alcohol, 28.0% by mass of BHMF, 6.5% by mass of water, and 2.8% by mass of nitrogen. 1.5 g of a silane coupling agent, 31 g of furfuryl alcohol, and 147 g of water were added to Resin d and mixed to obtain the adhesive composition of Production Example 6. The binder composition of Production Example 6 contained 20.0 mass % furfuryl alcohol, 23.0 mass % BHMF, 34.1 mass % furan resin, 20.0 mass % water, and 6.7 mass % nitrogen in the furan resin.

[0178] [Production Example 7]

[0179] In a three-necked flask, 587 g of furfuryl alcohol, 1.0 g of a 25% by mass aqueous sodium hydroxide solution, 195 g of 92% by mass paraformaldehyde, and 29 g of glutaric acid were added and reacted at 125°C under normal pressure for 2 hours. The mixture was then cooled to 90°C, 28 g of melamine was added, and the temperature was raised to 105°C and allowed to react at the same temperature for 2 hours. After the reaction, the mixture was cooled to 75°C, 8 g of urea was added, and the mixture was allowed to react at the same temperature for 20 minutes to obtain Resin e. Resin e contained 19.3% by mass of furfuryl alcohol, 27.5% by mass of BHMF, 7.3% by mass of water, and 2.8% by mass of nitrogen. To this Resin e, 1.5 g of a silane coupling agent, 43 g of furfuryl alcohol, and 141 g of water were added and mixed to obtain the adhesive composition of Production Example 7. The binder composition of Production Example 7 contained 20.0 mass % furanol, 22.4 mass % BHMF, 34.6 mass % furan resin, 20.0 mass % water, and 6.6 mass % nitrogen in the furan resin.

[0180] [Production Example 8]

[0181] The adhesive composition of Production Example 6 was prepared according to the KH-Y production method described in Japanese Patent Application No. 2014-501175 using the following steps. In a three-necked flask, 197 g of furfuryl alcohol, 196 g of 92% by mass paraformaldehyde, and 4.7 g of benzoic acid were added and reacted at 110°C under normal pressure for 1 hour. 394 g of furfuryl alcohol and 9.4 g of benzoic acid were further added to the reaction mixture, and the mixture was heated to 135°C and refluxed for 5 hours. The reaction temperature was 125°C after completion. 60 g of urea was then added, and the mixture was cooled to 60°C over approximately 40 minutes to obtain Resin f. Resin f contained 23.2% by mass of furfuryl alcohol, 14.8% by mass of BHMF, 7.3% by mass of water, and 3.3% by mass of nitrogen. 1.5 g of a silane coupling agent and 137 g of water were added to Resin f and mixed to obtain the adhesive composition of Production Example 8. The binder composition of Production Example 8 contained 20.0 mass % furanol, 12.7 mass % BHMF, 45.7 mass % furan resin, 20.0 mass % water, and 6.1 mass % nitrogen in the furan resin.

[0182] <Examples 1 to 21 and Comparative Examples 1 to 9>

[0183] [Manufacturing of Binder Composition for Casting Molds]

[0184] The urea-modified furan resin, furfuryl alcohol-formaldehyde resin, BHMF, furfuryl alcohol, water, and a silane coupling agent obtained in the above-described Preparation Examples were mixed at 40°C for 30 minutes to obtain the binder compositions for casting molds of Examples 1 to 16 and Comparative Examples 1 to 8. The binder compositions for casting molds of Examples 17 to 21, Comparative Example 9, and Reference Examples 1 and 2 used the compositions of Preparation Examples 1 to 8, respectively.

[0185] [Manufacturing of Mold Composition]

[0186] Under the conditions of 5°C and 55% RH, a curing agent composition was added to 100 parts by mass of furan regenerated silica sand, followed by 0.8 parts by mass of the binder composition for casting molds shown in Table 1, and these were mixed to obtain a casting mold composition. It should be noted that the curing agent composition used a xylenesulfonic acid / sulfuric acid curing agent (Kao Lightener US-3, Kao Lightener C-21: manufactured by Kao-Quaker). The amount of the curing agent composition added was 0.32 parts by mass relative to 100 parts by mass of furan regenerated silica sand, and the ratio of Kao Lightener US-3 to Kao Lightener C-21 was adjusted so that the compressive strength of the following sample became 0.20 to 0.35 MPa / 30 minutes. In addition, when the above-mentioned compressive strength was not satisfied when the addition amount was 0.32 parts by mass, only Kao Lightener US-3 was used and the addition amount was increased to satisfy the above-mentioned compressive strength.

[0187] [Evaluation of mold compression strength]

[0188] The mold composition immediately after mixing was filled into a cylindrical sample frame of 50 mm in diameter and 50 mm in height, and demoulded after 30 minutes. The compressive strength (MPa) was measured by the method described in JIS Z2604-1976, and this strength was used as the "compressive strength after 30 minutes". The "compressive strength after 30 minutes" was used as the standard for curing speed to confirm that the curing dose was appropriate. In addition, the mold composition was similarly filled into a sample frame, demoulded after 2 hours, and after 24 hours after filling, the compressive strength (MPa) was measured by the method described in JIS Z2604-1976, and this was used as the "compressive strength after 24 hours". The higher the numerical value, the higher the mold strength. The evaluation results are shown in Tables 1 and 2.

[0189] [Table 1]

[0190]

[0191] [Table 2]

[0192]

Claims

1. A binder composition for casting molds, comprising furfuryl alcohol as component A, bishydroxymethylfuran as component B, a resin as component C, and water as component D. The component C contains a furan resin, and the content of the furan resin in the component C is 80% by mass or more. The binder composition for casting molds satisfies the following conditions (1) to (5): Condition (1): The content of the component A in the binder composition for casting molds is 30.0% by mass or less; Condition (2): The content of the component D in the binder composition for casting mold formation is 25.0% by mass or less; Condition (3): The content of the component B in the binder composition for casting molds is 39.0% by mass or more and 95.0% by mass or less relative to the total content of the component B and the component C; Condition (4): The nitrogen content in the component C is 2.7% by mass or more and 22.0% by mass or less; Condition (5): When the content of the component B in the binder composition for casting molds is y and the nitrogen content of the component C is x, the following formula (1) is satisfied: 2.97x+15.2≤y (1).

2. The binder composition for casting molds according to claim 1, comprising furfuryl alcohol as component A, bishydroxymethylfuran as component B, a resin as component C, and water as component D. The binder composition for casting molds satisfies the following conditions (1'), (2'), (3) to (5): Condition (1'): The content of the component A in the binder composition for casting molds is 5.0% by mass or more and 30.0% by mass or less; Condition (2'): The content of the component D in the binder composition for casting molds is 5.0% by mass or more and 25.0% by mass or less; Condition (3): The content of the component B in the binder composition for casting molds is 39.0% by mass or more and 95.0% by mass or less relative to the total content of the component B and the component C; Condition (4): The nitrogen content in the component C is 2.7% by mass or more and 22.0% by mass or less; Condition (5): When the content of the component B in the binder composition for casting molds is y and the nitrogen content of the component C is x, the following formula (1) is satisfied: 2.97x+15.2≤y (1).

3. The binder composition for casting molds according to claim 1 or 2, wherein The content of Component A is 10.0% by mass or more and 30.0% by mass or less.

4. The binder composition for casting molds according to claim 1 or 2, wherein The content of Component A is 15.0% by mass or more and 30.0% by mass or less.

5. The binder composition for casting molds according to claim 1 or 2, wherein The content of the component D is 8.0% by mass or more and 25.0% by mass or less.

6. The binder composition for casting molds according to claim 1 or 2, wherein The content of the component D is 10.0% by mass or more and 20.0% by mass or less.

7. The binder composition for casting molds according to claim 1 or 2, which satisfies the following conditions (3) to (5): Condition (3): The content of the component B in the binder composition for casting molds is 51.0% by mass or more and 95.0% by mass or less relative to the total content of the component B and the component C; Condition (4): The nitrogen content in the component C is 2.7% by mass or more and 22.0% by mass or less; Condition (5): When the content of the component B in the binder composition for casting molds is y and the nitrogen content of the component C is x, the following formula (1) is satisfied: 2.97x+15.2≤y (1).

8. The binder composition for casting molds according to claim 1 or 2, which satisfies the following conditions (3'), (4) and (5): Condition (3'): The content of the component B in the binder composition for casting molds is 63.0% by mass or more and 95.0% by mass or less relative to the total content of the component B and the component C; Condition (4): The nitrogen content in the component C is 2.7% by mass or more and 22.0% by mass or less; Condition (5): When the content of the component B in the binder composition for casting molds is y and the nitrogen content of the component C is x, the following formula (1) is satisfied: 2.97x+15.2≤y (1).

9. The binder composition for casting molds according to claim 1 or 2, wherein The content of the component B in the binder composition for casting molds is 63.0% to 95.0% by mass relative to the total content of the components B and C, the nitrogen content in the component C is 3.7% to 17.0% by mass, and the formula (1) is satisfied.

10. The binder composition for casting molds according to claim 1 or 2, wherein The content of the component B in the binder composition for casting molds is 63.0% to 95.0% by mass relative to the total content of the component B and the component C, the nitrogen content in the component C is 4.6% to 13.9% by mass, and the following formula (2) is satisfied: 1.32x+57.4≤y (2).

11. The binder composition for casting molds according to claim 1 or 2, wherein The content of the component B in the binder composition for casting molds is 63.0% to 78.0% by mass relative to the total content of the component B and the component C, the nitrogen content in the component C is 4.6% to 13.9% by mass, and the following formula (2) is satisfied: 1.32x+57.4≤y (2).

12. The binder composition for casting molds according to claim 1 or 2, wherein The content of the furan resin in the component C is 90% by mass or more.

13. The binder composition for casting molds according to claim 1 or 2, wherein The content of the furan resin in the component C is 95% by mass or more.

14. The binder composition for casting molds according to claim 1 or 2, wherein The content of the furan resin in the component C is 98% by mass or more.

15. The binder composition for casting molds according to claim 1 or 2, wherein The content of the furan resin in the component C is substantially 100% by mass.

16. The binder composition for casting molds according to claim 1 or 2, wherein The furan resin includes one or more selected from urea-modified furan resins, furan methanol condensates, and condensates of furan methanol and aldehydes, and one or more selected from co-condensates of two or more selected from these.

17. The binder composition for casting molds according to claim 16, wherein The furan resin contains at least one selected from the urea-modified furan resin, furan methanol condensate, and condensate of furan methanol and aldehydes, and at least one selected from co-condensates of two or more selected therefrom, in a total amount of 90% by mass or more.

18. The binder composition for casting molds according to claim 16, wherein The furan resin contains at least one selected from the urea-modified furan resin, furan methanol condensate, and condensate of furan methanol and aldehydes, and at least one selected from co-condensates of two or more selected therefrom, in a total amount of 95% by mass or more.

19. The binder composition for casting molds according to claim 16, wherein The furan resin contains at least one selected from the urea-modified furan resin, furan methanol condensate, and condensate of furan methanol and aldehydes, and at least one selected from co-condensates of two or more selected therefrom, in a total amount of 98% by mass or more.

20. The binder composition for casting molds according to claim 16, wherein The total content of one or more selected from the urea-modified furan resin, furan methanol condensate, and condensate of furan methanol and aldehydes, and one or more selected from co-condensates of two or more selected therefrom, in the furan resin is substantially 100% by mass. 21 . A composition for casting molds, comprising the binder composition for casting molds according to claim 1 , and a curing agent composition containing a curing agent for curing the binder composition for casting molds.

22. A composition for a foundry mold comprising refractory particles, the binder composition for foundry mold making according to any one of claims 1 to 20, and a curing agent composition containing a curing agent for curing the binder composition for foundry mold making.

23. The casting mold composition according to claim 22, wherein The amount of the binder composition is 0.5 to 1.5 parts by mass, and the amount of the curing agent is 0.07 to 1 part by mass, relative to 100 parts by mass of the refractory particles.

24. A method for manufacturing a casting mold, comprising the following steps: a mixing step of mixing refractory particles, the binder composition for casting molds according to any one of claims 1 to 20, and a curing agent composition to obtain a casting mold composition, wherein the curing agent composition contains a curing agent that cures the binder composition for casting molds; and The curing step is to place the mold composition into a mold frame and cure the mold composition.

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