CN116234647A - Adhesive composition for casting mold - Google Patents

Abstract

The present invention provides a binder composition for mold shaping, which contains furanmethanol (component A), dimethylolfuran (component B), resin (component C) and water (component D) and satisfies the following conditions (1) to (5). Condition (1): the content of the component A in the binder composition for mold shaping is 30.0 mass% or less; condition (2): the content of the component D in the binder composition for mold shaping is 25.0 mass% or less; condition (3): the content of the component B in the binder composition for mold shaping is 39.0 mass% or more and 95.0 mass% or less relative to the total of the contents of the component B and the component C; condition (4): the nitrogen content in the component C is 2.7 mass% or more and 22.0 mass% or less; condition (5): when the content of the component B in the binder composition for mold shaping is y and the nitrogen content of the component C is x, the following formula (1) is satisfied: 2.97x+15.2.ltoreq.y (1). According to the present invention, a binder composition having a low content of monomeric furanmethanol, which can greatly improve the mold strength in a low-temperature environment, can be provided.

Description

Binder composition for casting mold

Technical Field

The present invention relates to a binder composition for casting molds.

Background Art

Generally speaking, acid curing casting mold is manufactured in the following manner: adding a casting mold molding binder composition containing acid curing resin and a curing agent composition containing sulfonic acid, sulfuric acid, phosphoric acid, etc. to refractory particles such as silica sand, after these are mixed, the mixed sand obtained is filled into the original mold such as wooden mold to solidify the acid curing resin. Acid curing resin uses furan resin, phenol resin, etc., and furan resin uses furan methanol-urea-formaldehyde resin, furan methanol-formaldehyde resin, furan methanol-phenol-formaldehyde resin, other known modified furan resins, etc. The manufacturing method of this casting mold can carry out a high degree of freedom molding operation, and in addition, the thermal performance of the casting mold is excellent, so high-quality castings can be manufactured, so it is widely used in castings such as casting machinery parts, construction machinery parts, or automotive parts.

An important condition for manufacturing a mold is to improve the working environment during mold manufacturing (during resin curing). In particular, in order to reduce furan carbinol volatilized during mold manufacturing, it is desirable to reduce monomeric furan carbinol in furan resin.

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

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

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 furanol, the mold release time can be shortened at the same usable time, thereby improving mold productivity, and increasing the curing speed and mold strength.

Summary of the invention

The present invention is a binder composition for casting, which contains furanol (component A), bishydroxymethyl furan (component B), resin (component C) and water (component D), and

The following conditions (1) to (5) are met.

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 mold-forming binder composition 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 mass % or more and 95.0 mass % or less relative to the total content of the component B and the component C.

Condition (4): The nitrogen content in the above-mentioned component C is 2.7 mass % or more and 22.0 mass % or less

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

2.97x+15.2≤y (1)

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.

The present invention also provides a casting mold composition comprising refractory particles, the above-mentioned casting mold binder composition, and a curing agent composition containing a curing agent for curing the casting mold binder composition.

In addition, the present invention is a method for manufacturing a casting mold, which includes: a mixing step, in which refractory particles, the above-mentioned binder composition for casting mold shaping, and a curing agent composition containing a curing agent that cures the binder composition for casting mold shaping are mixed to obtain a casting mold composition; and a curing step, in which the above-mentioned casting mold composition is loaded into a mold frame and the casting mold composition is cured.

DETAILED DESCRIPTION

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

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 have a low content of furanol as a single substance.

The present invention is a binder composition for casting, which contains furanol (component A), bishydroxymethyl furan (component B), resin (component C) and water (component D), and

The following conditions (1) to (5) are met.

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 mold-forming binder composition is 25.0% by mass or less

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

Condition (4): The nitrogen content in the above-mentioned component C is 2.7 mass % or more and 22.0 mass % or less

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

2.97x+15.2≤y (1)

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.

The present invention also provides a casting mold composition comprising refractory particles, the above-mentioned casting mold binder composition, and a curing agent composition containing a curing agent for curing the casting mold binder composition.

In addition, the present invention is a method for manufacturing a casting mold, which includes: a mixing step, in which refractory particles, the above-mentioned binder composition for casting mold shaping, and a curing agent composition containing a curing agent that cures the binder composition for casting mold shaping are mixed to obtain a casting mold composition; and a curing step, in which the above-mentioned casting mold composition is loaded into a mold frame and the casting mold composition is cured.

According to the present invention, a binder composition for mold making, a composition for mold making, a composition for mold making, and a method for producing a mold can be provided, which can significantly improve the mold strength in a low temperature environment and have a low content of furanol as a single substance.

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

<Binder composition for casting mold>

The binder composition for casting molds of the present embodiment (hereinafter also referred to simply as the binder composition) contains furanol (component A), bishydroxymethylfuran (component B), a resin (component C) and water (component D), and 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 mold-forming binder composition 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 mass % or more and 95.0 mass % or less relative to the total content of the component B and the component C.

Condition (4): The nitrogen content in the above-mentioned component C is 2.7 mass % or more and 22.0 mass % or less

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

2.97x+15.2≤y (1)

The binder composition can provide a binder composition that 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.

Compared with resin (ingredient C), bishydroxymethyl furan (ingredient B) has excellent reactivity with furan methanol (ingredient A) and reduces the viscosity of the above-mentioned binder composition. If the content of bishydroxymethyl furan (ingredient B) increases, the reactivity is improved, the viscosity of the binder composition is also reduced, and the compatibility with refractory particles is also improved, so the mold strength is improved. On the other hand, since the melting point of bishydroxymethyl furan (ingredient B) is high, if the content increases, the storage stability deteriorates (condition (3)). In addition, if the nitrogen content in the resin increases, the crosslinking reaction is promoted and the mold strength is improved. 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 bishydroxymethyl furan (ingredient B) relative to the total content of bishydroxymethyl furan (ingredient B) and the resin (ingredient C) is increased to reduce the viscosity, thereby improving the mold strength (condition (5)).

[Furanol (ingredient A)]

Based on the viewpoint of improving working environment, the content of the above-mentioned component A in the above-mentioned binder composition is 30.0 mass % or less, preferably 25.0 mass % or less, more preferably 20.0 mass % or less, and more preferably 15.0 mass % or less.Based on the viewpoint of improving mold strength, the content of the above-mentioned component A in the above-mentioned binder composition is preferably more than 0 mass %, more preferably 5.0 mass % or more, more preferably 10.0 mass % or more, more preferably 15.0 mass % or more, and more preferably 20.0 mass % or more.It should be noted that the content of component A can be measured by the method described in the embodiment.

[Bis(hydroxymethyl)furan (ingredient B)]

From the viewpoint of reducing the content of monomeric furanol 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.

Based on the viewpoint of reducing the content of monomeric furan methanol and greatly improving the casting 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, more 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 embodiment.

[Resin (component C)]

As long as the component C is a resin used as a binder for casting molds, it can be used without particular limitation. 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 resin, condensates of melamine and aldehydes, condensates of urea and aldehydes, and condensates of ethylene urea and aldehydes can be exemplified. Based on the viewpoint of reducing the content of monomeric furan carbinol and greatly improving the strength of the mold under low temperature environment, the component C preferably contains furan resin. It should be noted that the component C does not include furan carbinol.

The furan resin is obtained by polymerizing a monomer composition containing furanol, and any resin can be used without particular limitation as long as it can be used as a binder for casting molds. From the viewpoint of reducing the content of monomeric furan carbinol and significantly improving the casting strength in a 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: a condensate of furan carbinol and urea; a condensate of furan carbinol and melamine; a condensate of furan carbinol and ethylene urea; a condensate of furan carbinol, urea and aldehydes (urea-modified furan resin); a condensate of furan carbinol, melamine and aldehydes; a condensate of furan carbinol, ethylene urea and aldehydes; a condensate of furan carbinol; a condensate of furan carbinol and aldehydes; and a condensate 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.

Examples of the aldehydes include formaldehyde, acetaldehyde, glyoxal, furfural, terephthalaldehyde, hydroxymethylfurfural, and the like, and one or more of these may be used appropriately. From the perspective of improving mold strength, formaldehyde is preferably used, and from the perspective of reducing the amount of formaldehyde generated during molding, furfural, terephthalaldehyde, and hydroxymethylfurfural are preferably used.

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.

The furan resin can be produced by a known method. For example, when 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 furan alcohol.

From the viewpoint of reducing the content of monomeric furan carbinol and greatly improving the casting 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 two or more co-condensates selected therefrom in the above-mentioned furan resin is preferably 90% by mass or more, more preferably 95% by mass or more, further preferably 98% by mass or more, further preferably substantially 100% by mass, and further preferably 100% by mass. It should be noted that in this specification, "substantially" refers to an amount that can contain impurities.

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 mass % or more, more preferably 90 mass % or more, further preferably 95 mass % or more, further preferably 98 mass % or more, further preferably substantially 100 mass %, and further preferably 100 mass %.

Based on improving the crosslinking density of the resin and greatly improving the mold strength under low temperature environment, the nitrogen content (in this specification, nitrogen content refers to the content of nitrogen atoms) in the above-mentioned component C is more than 2.7 mass %, preferably more than 2.8 mass %, more preferably more than 3.7 mass %, and more preferably more than 4.6 mass %. Based on maintaining good mixability with refractory aggregate, for the viewpoint of suppressing mold strength reduction, the nitrogen content in the above-mentioned component C is below 22.0 mass %, preferably below 21.0 mass %, more preferably below 17.0 mass %, and more preferably below 13.9 mass %. It should be noted that the nitrogen content in component C can be measured by the method described in the embodiment.

Based on the viewpoint of increasing the crosslinking density of the resin and greatly improving the mold strength under low temperature environment, the content of the above-mentioned component C in the above-mentioned binder composition is preferably 5.0 mass % or more, more preferably 6.0 mass % or more, and further preferably 7.0 mass % or more. Based on maintaining good kneading property with refractory aggregates and suppressing the viewpoint of reducing mold strength, the content of the above-mentioned component C in the above-mentioned binder composition is preferably 45.0 mass % or less, more preferably 43.0 mass % or less, and further preferably 42.0 mass % or less.

Based on the viewpoint of greatly improving the mold strength under low temperature environment by increasing the crosslinking density of the resin, the nitrogen content in the above-mentioned binder composition is preferably more than 0.1% by mass, more preferably more than 0.2% by mass. Based on maintaining good kneading property with refractory aggregate, the viewpoint of suppressing the reduction of mold strength, the nitrogen content in the above-mentioned binder composition is preferably less than 3.5% by mass, more preferably less than 3.2% by mass, and further preferably less than 3.0% by mass. It should be noted that the nitrogen content in the binder composition can be measured by the method described in the embodiment.

Based on the viewpoint of increasing the crosslinking density of the resin and greatly improving the casting strength in a low temperature environment, the content of the above-mentioned component B in the above-mentioned binder composition is 39.0 mass % or more relative to the total content of the above-mentioned component B and the above-mentioned component C, preferably 51.0 mass % or more, and more 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 95.0 mass % or less relative to the total content of the above-mentioned component B and the above-mentioned component C, preferably 92.0 mass % or less, more preferably 90.0 mass % or less, and further preferably 78.0 mass % or less.

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 formula (1) from the viewpoint of reducing the content of monomeric furanol and significantly improving the mold strength in a low temperature environment.

In the above-mentioned binder composition, from the viewpoint of reducing the content of monomeric furanol and significantly improving the casting 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 satisfies the above-mentioned formula (1).

In the above-mentioned binder composition, from the viewpoint of reducing the content of monomeric furanol and significantly improving the casting 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 satisfies the above-mentioned formula (1).

In the above-mentioned binder composition, from the viewpoint of reducing the content of monomeric furanol and significantly improving the casting 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 satisfies the above-mentioned formula (1).

In the above-mentioned binder composition, from the viewpoint of reducing the content of monomeric furanol and significantly improving the casting 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 satisfies the above-mentioned formula (1).

In the above-mentioned binder composition, from the viewpoint of reducing the content of monomeric furanol and significantly improving the casting 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).

1.32x+57.4≤y (2)

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 satisfies the above-mentioned formula (2).

[Water (ingredient D)]

Based on the viewpoint of 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. Based on the viewpoint of adjusting 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, and 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 embodiment.

[Curing accelerator]

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

Examples of the phenol derivatives include resorcinol, cresol, hydroquinone, phloroglucinol, methylene bisphenol, etc. From the viewpoint 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 further preferably 3 to 10% by mass.

As the above-mentioned aromatic dialdehyde, there can be mentioned: terephthalaldehyde, o-phthalaldehyde and isophthalaldehyde, and derivatives thereof. These derivatives refer to compounds having substituents such as alkyl groups on the aromatic ring of an aromatic compound having two formyl groups as a basic skeleton. From the viewpoint of fully dissolving the aromatic dialdehyde in the furan resin and suppressing the odor of the aromatic dialdehyde itself, the content of the aromatic dialdehyde in the above-mentioned binder composition is preferably 0.1 to 15% by mass, more preferably 0.5 to 10% by mass, and further preferably 1 to 5% by mass.

As the above-mentioned tannins, condensed tannins and hydrolyzed tannins can be mentioned. As examples of these condensed tannins and hydrolyzed tannins, tannins having a pyrogallol skeleton and a resorcinol skeleton can be mentioned. In addition, bark extracts containing these tannins, extracts extracted from natural materials such as leaves, fruits, seeds, and galls parasitic on plants, etc. can also be added. From the viewpoint of increasing the curing speed and the viewpoint of increasing the mold strength, the content of tannins in the above-mentioned binder composition is preferably 0.2 to 10% by mass, more preferably 1.0 to 7% by mass, and further preferably 1.9 to 5% by mass.

From the viewpoint of workability when manufacturing the mold composition and the mold, 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 Examples.

The above-mentioned adhesive composition may also include additives such as silane coupling agents. For example, if the above-mentioned adhesive composition includes a silane coupling agent, the final strength of the obtained casting mold can be further improved, so it is preferred. As a 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; 3-glycidyloxypropyltrimethoxysilane, 3-glycidyloxypropyltriethoxysilane, 3-glycidyloxypropylmethyldimethoxysilane, 3-glycidyloxypropylmethyldiethoxysilane, 3-glycidyloxypropyltriethoxysilane and other epoxysilanes; urea silane, mercaptosilane, sulfosilane, methacryloxysilane, acryloxysilane, etc. can be used. Preferred are aminosilane, epoxysilane, and ureidosilane. More preferred are aminosilane and epoxysilane. Among aminosilanes, preferred is N-β-(aminoethyl)-γ-aminopropylmethyldimethoxysilane. Among epoxysilanes, preferred is 3-glycidyloxypropylmethyldimethoxysilane.

From the viewpoint of improving the mold strength, the content of the silane coupling agent in the above-mentioned binder composition is preferably 0.01% by mass or more, more preferably 0.05% by mass or more. From the same viewpoint, the content of the silane coupling agent in the above-mentioned binder composition is preferably 5% by mass or less, more preferably 3% by mass or less, further preferably 1% by mass or less, further preferably 0.5% by mass or less.

The binder composition for mold molding of the present embodiment is suitable for molding a self-hardening mold. Here, the self-hardening mold is a mold as follows: when the binder composition and the curing agent are mixed in the sand, the polymerization reaction proceeds over time and the mold is cured. The temperature of the sand used at this time is in the range of -20°C to 50°C, preferably 0°C to 40°C. For sand at this temperature, a curing agent of an appropriate amount is selected and added to the sand, thereby allowing the mold to be properly cured.

<Molding composition>

The casting mold making composition of the present embodiment contains the above-mentioned binder composition and a curing agent composition containing a curing agent for curing the casting mold making binder composition. The casting mold making composition of the present embodiment has the same effects as the above-mentioned binder composition.

[Curing agent composition]

The curing agent composition can be used without particular limitation as long as it contains a curing agent that cures the binder composition. As the curing agent, an acid curing agent can be exemplified, and one or more of the following curing agents and the like, such as sulfonic acid compounds such as xylenesulfonic acid (especially m-xylenesulfonic acid), toluenesulfonic acid (especially p-toluenesulfonic acid), and methanesulfonic acid can be used; phosphoric acid compounds such as phosphoric acid and acidic phosphate esters; sulfuric acid. From the viewpoint 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.

The content of the above-mentioned solvent in the above-mentioned curing agent composition can be appropriately adjusted according to the temperature of the working environment or the temperature of the refractory particles in order to obtain the desired reaction speed and mold strength. Generally speaking, based on the viewpoint of dissolving the curing agent composition, it is preferably 5% by mass or more, more preferably 10% by mass or more, and more preferably 20% by mass or more. Based on the viewpoint of improving mold strength, the content of the above-mentioned solvent in the above-mentioned curing agent composition is preferably 90% by mass or less, more preferably 80% by mass or less, and more preferably 70% by mass or less.

From the viewpoint of improving mold strength, the content of the above-mentioned curing agent in the above-mentioned curing agent composition is preferably 10 mass % or more, more preferably 20 mass % or more, and further preferably 30 mass % or more. From the viewpoint of dissolving the curing agent composition, the content of the above-mentioned curing agent in the above-mentioned curing agent composition is preferably 95 mass % or less, more preferably 90 mass % or less, and further preferably 80 mass % or less.

Regarding the mass ratio of the above-mentioned adhesive composition to the above-mentioned curing agent, from 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.

[Mold composition]

The casting composition of this embodiment contains refractory particles, the above-mentioned binder composition, and the above-mentioned curing agent composition. The casting composition of this embodiment has the same effects as those of the above-mentioned binder composition.

[Refractory particles]

As the refractory particles, one or more of silica sand, chrome sand, zircon sand, olivine sand, alumina sand, mullite sand, synthetic mullite sand and other conventionally known refractory particles can be used, and in addition, materials obtained by recycling used refractory particles or materials obtained by regenerating the used refractory particles can also be used. Among them, silica sand is preferably included.

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.

＜Method for manufacturing casting mold＞

The method for manufacturing a mold of the present embodiment includes: a mixing step of mixing refractory particles, the binder composition and the curing agent composition to obtain a mold composition; and a curing step of placing the mold composition into a mold frame and curing the mold composition. The method for manufacturing a mold has the same effect as the binder composition.

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 to manufacture the composition for casting mold, the composition for casting mold can be 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 the mold, the above-mentioned binder composition, the above-mentioned curing agent composition and refractory particles are preferably mixed to obtain the composition for casting mold. In addition, based on the viewpoint of improving the strength of the mold, it is preferred to add a curing agent composition to the refractory particles and mix, then add a binder composition and mix. In addition, when using two or more curing agent compositions, each curing agent composition can be added after mixing, and each curing agent composition can also be added respectively.

In the mixing step, as a method for mixing the raw materials, a known general method can be used, and examples thereof 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.

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.

For the above embodiments, the present invention further discloses the following compositions, manufacturing methods or uses.

<1> A binder composition for casting, comprising furanol (component A), bishydroxymethylfuran (component B), a resin (component C) and water (component D), and

The following conditions (1) to (5) are met.

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 mold-forming binder composition 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 mass % or more and 95.0 mass % or less relative to the total content of the component B and the component C.

Condition (4): The nitrogen content in the above-mentioned component C is 2.7 mass % or more and 22.0 mass % or less

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

2.97x+15.2≤y (1)

<2> The binder composition for casting according to <1>, comprising furanol (component A), bishydroxymethylfuran (component B), a resin (component C) and water (component D), and

The following conditions (1) to (5) are met.

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

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

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

Condition (4): The nitrogen content in the above-mentioned component C is 2.7 mass % or more and 22.0 mass % or less

Condition (5): When the content of the component B in the above-mentioned binder composition for casting molds is y and the nitrogen content of the above-mentioned 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 <1> or <2>, wherein the content of the component A is 10.0 mass % to 30.0 mass %.

<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 mass % to 30.0 mass %.

<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 mass % or more and 25.0 mass % or less.

<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 mass % to 20.0 mass %.

<7> The binder composition for casting molds according to any one of <1> to <6>, 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 mass % or more and 95.0 mass % or less relative to the total content of the component B and the component C.

Condition (4): The nitrogen content in the above-mentioned component C is 2.7 mass % or more and 22.0 mass % or less

Condition (5): When the content of the component B in the above-mentioned binder composition for casting molds is y and the nitrogen content of the above-mentioned 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 any one of <1> to <7>, which satisfies the following conditions (3) to (5).

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

Condition (4): The nitrogen content in the above-mentioned component C is 2.7 mass % or more and 22.0 mass % or less

Condition (5): When the content of the component B in the above-mentioned binder composition for casting molds is y and the nitrogen content of the above-mentioned 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 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.

<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.

<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.

<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.

<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.

<14> A 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 co-condensates selected from two or more thereof.

<15> A 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 from them in the above-mentioned furan resin is 90% by mass or more.

<16> A binder composition for casting mold forming 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 from them in the above-mentioned furan resin is 95% by mass or more.

<17> A 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 co-condensates selected from two or more selected from them in the above-mentioned furan resin is 98% by mass or more.

<18> A 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, furanmethanol condensate and condensate of furanmethanol and aldehydes in the above-mentioned furan resin, and one or more selected from co-condensates of two or more selected therefrom is substantially 100% by mass.

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

<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.

<21> The casting composition according to <20>, 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, based on 100 parts by mass of the refractory particles.

<22> A method for manufacturing a casting mold, comprising: a mixing step of mixing refractory particles, a binder composition for casting mold shaping 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 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.

Example

Hereinafter, embodiments and the like which specifically illustrate the present invention will be described.

<Measurement methods of physical properties>

[Water content]

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

[Content of furanol and bis(hydroxymethylfuran)]

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

·Standard curve: prepared using furanol and bis(hydroxymethylfuran).

Internal standard solution: 1,6-hexanediol

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

Column temperature: 80～200℃(8℃/min)

Injection temperature: 210℃

Detector temperature: 250℃ Carrier gas: 50mL/min (He)

[Nitrogen content]

The measurement was carried out based on the Kjeldahl method shown in JIS K 6451-2.

[Viscosity]

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

＜Resin production method＞

[Urea modified furan resin]

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

[Furan methanol condensate]

492 g of furan methanol and 8 g of glutaric acid were added to a three-necked flask and reacted at 100° C. for 5 hours under normal pressure. Then, the pH value 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 furan methanol. The composition of the obtained reactant was 79.0% by mass of furan methanol condensate and 21.0% by mass of furan methanol.

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

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

<Production Example of Adhesive Composition>

[Production Example 1]

Resin a was obtained by the procedure described in paragraph 0055 of <Production of Condensate 1> of Japanese Patent Application Laid-Open No. 2013-151019. The unreacted furan carbinol and water content of the resin a were measured, and based on the measurement results, the resin a, furan carbinol, water and silane coupling agent were used to prepare a binder composition of Production Example 1 in such a manner that the furan carbinol content was 50% by mass, the water content was 10% by mass and the silane coupling agent content was 0.15% by mass.

[Production Example 2]

The above resin a, furancarbinol, water and a silane coupling agent were used to prepare an adhesive composition of Production Example 2 such that the furancarbinol content was 50 mass %, the water content was 20 mass % and the silane coupling agent content was 0.15 mass %.

[Production Example 3]

Into a three-necked flask, 587g of furan methanol, 1.0g of 25% by mass sodium hydroxide aqueous solution, 159g of 92% by mass polyformaldehyde, and 29g of glutaric acid were added, and the mixture was reacted at 125°C for 3 hours under normal pressure. Then, the mixture was cooled to 90°C, 35g of urea was added, and the mixture was heated to 105°C and reacted at the same temperature for 2 hours. After the reaction, the mixture was cooled to 75°C, 7g of urea was added, and the mixture was reacted at the same temperature for 20 minutes to obtain resin b. The furan methanol in resin b was 20.0% by mass, the BHMF was 29.5% by mass, the water was 6.8% by mass, and the nitrogen content was 2.4% by mass. 1.5g of silane coupling agent, 36g of furan methanol, and 145g of water were added to the above resin b and mixed to obtain the binder composition of Manufacturing 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.

[Production Example 4]

Into a three-necked flask, 588g of furan methanol, 1.0g of 25% by mass sodium hydroxide aqueous solution, 159g of 92% by mass polyformaldehyde, and 29g of benzoic acid were added, and the mixture was reacted at 125°C for 2 hours under normal pressure. Thereafter, the mixture was cooled to 90°C, 10g of 92% by mass polyformaldehyde and 50g of urea were added, the mixture was heated to 105°C, and the mixture was reacted at the same temperature for 2 hours. After the reaction, the mixture was cooled to 75°C, 11g of urea was added, and the mixture was reacted at the same temperature for 20 minutes to obtain resin c. The furan methanol in the above resin c was 22.0% by mass, the BHMF was 26.4% by mass, the water was 7.4% by mass, and the nitrogen content was 3.3% by mass. 1.5g of silane coupling agent, 13g of furan methanol, and 138g of water were added to the above resin c and mixed to obtain the binder composition of manufacturing 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.

[Production Example 5]

359 g of the above resin c, 121 g of furan carbinol, 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 Manufacturing Example 5. The furan carbinol content in the adhesive composition of Manufacturing Example 5 was 20.0% by mass, the BHMF content was 44.0% by mass, the furan resin content was 14.7% by mass, the water content was 20.0% by mass, and the nitrogen content in the furan resin was 8.1% by mass.

[Production Example 6]

Into a three-necked flask, 569g of furan methanol, 0.9g of 25% by mass sodium hydroxide aqueous solution, 154g of 92% by mass polyformaldehyde, and 28g of glutaric acid were added, and the mixture was reacted at 125°C for 3 hours under normal pressure. Then, the mixture was cooled to 90°C, 58g of ethylene urea was added, and the mixture was heated to 105°C and reacted at the same temperature for 3 hours. After the reaction, the mixture was cooled to 75°C, 8g of urea was added, and the mixture was reacted at the same temperature for 20 minutes to obtain resin d. The furan methanol in resin d was 20.6% by mass, the BHMF was 28.0% by mass, the water was 6.5% by mass, and the nitrogen content was 2.8% by mass. 1.5g of silane coupling agent, 31g of furan methanol, and 147g of water were added to the above resin d and mixed to obtain the binder composition of manufacturing example 6. The binder composition of Production Example 6 contained 20.0 mass % furanol, 23.0 mass % BHMF, 34.1 mass % furan resin, 20.0 mass % water, and 6.7 mass % nitrogen in the furan resin.

[Production Example 7]

Into a three-necked flask, 587g of furan methanol, 1.0g of 25% by mass sodium hydroxide aqueous solution, 195g of 92% by mass polyformaldehyde, and 29g of glutaric acid were added, and the mixture was reacted at 125°C for 2 hours under normal pressure. Then, the mixture was cooled to 90°C, 28g of melamine was added, and the mixture was heated to 105°C and reacted at the same temperature for 2 hours. After the reaction, the mixture was cooled to 75°C, 8g of urea was added, and the mixture was reacted at the same temperature for 20 minutes to obtain resin e. The furan methanol in resin e was 19.3% by mass, the BHMF was 27.5% by mass, the water was 7.3% by mass, and the nitrogen content was 2.8% by mass. 1.5g of silane coupling agent, 43g of furan methanol, and 141g of water were added to the above resin e and mixed to obtain the adhesive composition of manufacturing 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.

[Production Example 8]

According to the manufacturing method of KH-Y described in Japanese Patent Table 2014-501175, the adhesive composition of Manufacturing Example 6 was manufactured in the following steps. 197g of furan methanol, 196g of 92% by mass paraformaldehyde, and 4.7g of benzoic acid were added to a three-necked flask and reacted at 110°C for 1 hour under normal pressure. 394g of furan methanol and 9.4g of benzoic acid were further added to the reactant, the temperature was raised to 135°C, and refluxed for 5 hours. The temperature after the reaction was 125°C. Then, 60g of urea was added and cooled to 60°C for about 40 minutes to obtain resin f. The furan methanol in the above resin f was 23.2% by mass, BHMF was 14.8% by mass, water was 7.3% by mass, and the nitrogen content was 3.3% by mass. 1.5g of silane coupling agent and 137g of water were added to the above resin f and mixed to obtain the adhesive composition of Manufacturing 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.

<Examples 1 to 21 and Comparative Examples 1 to 9>

[Manufacturing of Binder Composition for Casting Molds]

The urea-modified furan resin, furan carbinol-formaldehyde resin, BHMF, furan carbinol, water and silane coupling agent obtained in the above-mentioned 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 shown above, respectively.

[Manufacturing of casting mold composition]

Under the conditions of 5°C and 55% RH, a curing agent composition is added to 100 parts by mass of furan regenerated silica sand, and then 0.8 parts by mass of a binder composition for mold shaping shown in Table 1 is added, and these are mixed to obtain a composition for mold. It should be noted that the curing agent composition uses 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 is 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 is adjusted so that the compressive strength of the following sample becomes 0.20 to 0.35 MPa/30 minutes. In addition, when the above-mentioned compressive strength is not satisfied when the addition amount is 0.32 parts by mass, only Kao Lightener US-3 is used, and the addition amount is increased so that it satisfies the above-mentioned compressive strength.

[Evaluation of mold compression strength]

The mold composition just after kneading is immediately filled into a cylindrical sample frame with a diameter of 50 mm and a height of 50 mm. After 30 minutes, demoulding is performed, and the compressive strength (MPa) is measured by the method described in JIS Z2604-1976, and this strength is used as the "compressive strength after 30 minutes". The "compressive strength after 30 minutes" is used as a standard for the curing speed to confirm that the curing dosage is appropriate. In addition, the mold composition is similarly filled into the sample frame, demoulding is performed after 2 hours, and 24 hours after filling, the compressive strength (MPa) is measured by the method described in JIS Z2604-1976 as the "compressive strength after 24 hours". The higher the value, the higher the mold strength. The evaluation results are shown in Tables 1 and 2.

[Table 1]

[Table 2]

Claims (7)

1. A binder composition for mold molding, which contains furan methanol as component A, bismethylolfuran as component B, resin as component C, and water as component D, The binder composition for mold molding satisfies the following conditions (1) to (5): Condition (1): The content of the component A in the binder composition for casting molding is 30.0% by mass or less; Condition (2): The content of the component D in the binder composition for casting molding is 25.0% by mass or less; Condition (3): The content of the component B in the binder composition for casting molding is 39.0 mass% or more and 95.0 mass% or less with respect to the total content of the component B and the component C; Condition (4): The nitrogen content in the component C is not less than 2.7% by mass and not more than 22.0% by mass; Condition (5): When the content of the component B in the casting mold molding binder composition 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 molding according to claim 1, 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. 3. The casting mold molding binder composition according to claim 2, wherein the furan resin contains one selected from urea-modified furan resin, furan methanol condensate and furan methanol and aldehyde condensate One or more of the above, and two or more cocondensates selected from them. 4. The binder composition for casting molding according to claim 3, wherein, in the furan resin, the selected from the urea-modified furan resin, furan methanol condensate and furan methanol and aldehyde condensate The total content of one or more kinds of cocondensates selected from these and two or more kinds of cocondensates selected from them is 90% by mass or more. 5. A composition for molding a mold, comprising the binder composition for molding a mold according to any one of claims 1 to 4, and a curing agent composition comprising A curing agent that cures with a binder composition. 6. A composition for casting, which contains refractory particles, the binder composition for casting molding according to any one of claims 1 to 4, and a curing agent composition, the curing agent composition comprising A curing agent for curing the binder composition for casting. 7. A method for manufacturing a mold, comprising the following steps: a mixing step of mixing the refractory particles, the binder composition for molding molding according to any one of claims 1 to 4, and a curing agent composition to obtain a molding composition, the curing agent composition comprising a curing agent for curing the binder composition for molding; and A curing step of putting the molding composition into a mold frame and curing the molding composition.