WO2023054430A1

WO2023054430A1 - Mold composition

Info

Publication number: WO2023054430A1
Application number: PCT/JP2022/036073
Authority: WO
Inventors: 昌彦鍵谷
Original assignee: 花王株式会社
Priority date: 2021-09-29
Filing date: 2022-09-28
Publication date: 2023-04-06
Also published as: JP2023050161A; CN117858773A

Abstract

The present invention is a mold composition comprising fire-resistant particles, a phenol resin, a curing agent, a compound represented by general formula (1), and a C8-22 fatty acid. The present invention makes it possible to provide a mold composition which has excellent fluidity while suppressing deterioration in handleability during storage or during use of a binding agent composition for mold production and a curing agent composition for mold production. RO-(CH₂CH₂O)n-H (1) (In general formula (1), R represents a linear or branched C8-22 alkyl group or alkenyl group, and n represents the average number of moles added, and is a number from 1.2 to 23.)

Description

mold composition

The present invention relates to a mold composition.

Various organic binders are used as binders for manufacturing molds. Among them, alkali phenol resins are widely used, especially in the field of cast steel, as organic binders that can improve casting quality and working environment.

However, when making a mold by kneading an alkali phenol resin and, in particular, recycled sand of artificial sand, i.e. recovered sand intended to be reused after being cast once or recycled sand repeatedly used several times, the mold composition The fluidity of the material is remarkably deteriorated compared to new sand, and close packing is not possible. As a result, casting defects such as sand inclusions, seizures, and insertions occur in the resulting castings, resulting in a reduction in the quality of the castings.

In response to the above issues, various proposals have been made to improve the fluidity of foundry sand. For example, when molding a mold by kneading a self-hardening water-soluble phenolic resin and a curing agent using artificial sand, which is a refractory particle, a surfactant or lubricant is added to improve the fluidity of the mold composition. Japanese Patent Application Laid-Open No. 10-216895 discloses that a nonionic surfactant is added to a binder for the purpose of improving the fluidity of kneaded sand and reducing the generation of air bubbles in a one-liquid type. Japanese Patent Application Laid-Open No. 2009-40896 discloses that it is contained in a curing agent.

The present invention
A mold composition containing refractory particles, a phenolic resin, a curing agent, a compound represented by the following general formula (1), and a fatty acid having 8 to 22 carbon atoms.
RO—(CH ₂ CH ₂ O)n—H (1)
(In the general formula (1), R represents a linear or branched alkyl group or alkenyl group having 8 to 22 carbon atoms, n represents the average number of added moles, and a number of 1.2 to 23 show.)

The present invention also provides a curing agent composition for mold making, comprising a curing agent, a compound represented by the following formula (1), and a fatty acid having from 8 to 22 carbon atoms.
RO—(CH ₂ CH ₂ O)n—H (1)
(In the general formula (1), R represents a linear or branched alkyl group or alkenyl group having 8 to 22 carbon atoms, n represents the average number of added moles, and a number of 1.2 to 23 show.)

The present invention also provides a method for producing a mold composition, comprising the step of mixing refractory particles, a binder composition for mold molding containing a phenolic resin, and the curing agent composition for mold molding.

Cross-sectional view of a wooden mold for evaluating the smoothness of the mold surface Appearance photograph of the mold according to the example manufactured for surface smoothness evaluation Appearance photograph of a mold according to a comparative example manufactured for evaluation of surface smoothness Cross-sectional view of molds, etc. in casting quality evaluation Cross-sectional view of molds, etc. in casting quality evaluation Cross-sectional view of molds, etc. in casting quality evaluation Cross-sectional view of molds, etc. in casting quality evaluation Appearance photograph of casting according to an example in casting quality evaluation Appearance photograph of casting according to comparative example in casting quality evaluation

Detailed description of the invention

In Japanese Patent Laid-Open No. 10-216895, when a surfactant is added to a binder (alkali phenol resin), air bubbles are generated during preparation and use, making handling inconvenient. Further, when a lubricant such as fatty acid is added to the binder, the fatty acid is neutralized and precipitates as an aggregate, which makes handling during storage inconvenient. On the other hand, in Japanese Unexamined Patent Application Publication No. 2009-40896, when a nonionic surfactant is added to a curing agent for an alkali phenol resin, even if a certain amount or more of the nonionic surfactant is added, the effect of improving fluidity peaks out. As a result, it is difficult to significantly improve liquidity.

The present invention provides a mold composition excellent in fluidity while suppressing deterioration of handleability during use and storage of a binder composition for mold making and a curing agent composition for mold making, and a method for producing the same. do.

INDUSTRIAL APPLICABILITY According to the present invention, a mold composition having excellent fluidity while suppressing deterioration of handleability during use and storage of a binder composition for mold making and a curing agent composition for mold making, and a method for producing the same. can be provided.

An embodiment of the present invention will be described below.

<Mold composition>
The mold composition of this embodiment is
It contains refractory particles, a phenolic resin, a curing agent, a compound represented by the following general formula (1), and a fatty acid having 8 to 22 carbon atoms.
RO—(CH ₂ CH ₂ O)n—H (1)
(In the general formula (1), R represents a linear or branched alkyl group or alkenyl group having 8 to 22 carbon atoms, n represents the average number of added moles, and a number of 1.2 to 23 show.)

The mold composition of this embodiment has excellent fluidity. Although the reason why the mold composition of the present embodiment exhibits such an effect is not clear, it is considered as follows.

When a nonionic surfactant is added to a casting composition consisting of a phenolic resin, a curing agent, and refractory particles, the surface tension of the mixture of the phenolic resin and the curing agent is lowered, and the lubricity between the refractory particles is improved. We believe that liquidity will improve. On the other hand, if the casting composition contains a fatty acid, it reacts with the alkali metal in the water-soluble phenolic resin and precipitates as a fatty acid salt. That is, the fluidity improving effect obtained by containing a nonionic surfactant and the fluidity improving effect obtained by containing a fatty acid have different mechanisms. It is considered that the combined use of additives with different mechanisms greatly improved the fluidity-improving effect.

[Refractory particles]
As the refractory particles, conventionally known ones such as silica sand, chromite sand, zircon sand, olivine sand, alumina sand, mullite sand, synthetic mullite sand, and alumina ball sand can be used. Reclaimed sand that has been recovered and reclaimed can also be used. The refractory particles can be used alone or in combination of two or more.

The average particle size of the refractory particles is preferably 50 μm or more, more preferably 100 μm or more, and still more preferably 150 μm or more from the viewpoint of improving mold strength and economic efficiency. , preferably 1000 μm or less, more preferably 800 μm or less, still more preferably 600 μm or less. In addition, in this specification, an average particle diameter is measured by the method as described in an Example.

[Phenolic resin]
The phenolic resin is generally obtained by polycondensing a phenolic compound and an aldehyde compound under alkaline conditions. Of these, phenolic compounds include phenol, bisphenol A, bisphenol F, cresol, 3,5-xylenol, resorcinol, catechol, nonylphenol, p-tert-butylphenol, isopropenylphenol, phenylphenol, and other substituted phenols. and mixtures of various phenolic compounds such as cashew nut shell liquid can be used singly or in combination of two or more. As the aldehyde compound, formaldehyde, acetaldehyde, furfural, glyoxal and the like can be used singly or in combination of two or more. These compounds can be used as an aqueous solution as needed. In addition to these, urea, melamine, monomers that can be condensed with aldehyde compounds such as cyclohexanone, monohydric aliphatic alcohol compounds such as methanol, ethanol, isopropyl alcohol, normal propyl alcohol, butyl alcohol, water-soluble polymers polyacrylic acid salt, cellulose derivative polymer, polyvinyl alcohol, lignin derivative and the like may be mixed.

Alkaline catalysts used in the synthesis of the phenolic resin include hydroxides of alkali metals such as LiOH, NaOH and KOH, with NaOH and KOH being particularly preferred. Moreover, you may mix and use these alkali catalysts.

The phenol resin is preferably an aqueous solution, and the solid content mass (solid mass after drying at 105 ° C. for 3 hours) is preferably 30% by mass or more, more preferably 50% by mass or more, from the viewpoint of improving the mold strength. preferable. The solid content mass of the phenol resin aqueous solution is preferably 85% by mass or less, more preferably 75% by mass or less, from the viewpoint of improving mold strength and improving workability. Further, the solid content mass of the phenol resin aqueous solution is preferably 30 to 80% by mass, more preferably 50 to 75% by mass, from the viewpoint of improving mold strength and improving workability.

From the viewpoint of improving mold strength, the weight average molecular weight (Mw) of the phenol resin is preferably 500 or more, more preferably 800 or more, and even more preferably 1200 or more. The weight-average molecular weight (Mw) of the phenolic resin is preferably 8000 or less, more preferably 5000 or less, and even more preferably 3000 or less, from the viewpoint of improving mold strength and workability. Further, the weight average molecular weight (Mw) of the phenol resin is preferably 500 to 8000, more preferably 800 to 5000, and even more preferably 1200 to 3000, from the viewpoint of improving mold strength and improving workability. The weight average molecular weight of the phenol resin is measured by the method described in Examples.

From the viewpoint of improving mold strength, the content of the phenol resin with respect to 100 parts by mass of the refractory particles in the mold composition is preferably 0.1 parts by mass or more, more preferably 0.2 parts by mass or more. .3 parts by mass or more is more preferable. The content of the phenol resin with respect to 100 parts by mass of the refractory particles in the mold composition is preferably 5 parts by mass or less, more preferably 3 parts by mass or less, from the viewpoint of improving workability and economic efficiency. , 1 part by mass or less is more preferable. In addition, the content of the phenol resin with respect to 100 parts by mass of the refractory particles in the mold composition is 0.1 to 5 from the viewpoint of improving mold strength, improving workability, and economic efficiency. Parts by weight are preferred, 0.2 to 3 parts by weight are more preferred, and 0.3 to 1 parts by weight are even more preferred.

[Compound represented by the general formula (1)]
The compound represented by the general formula (1) includes compounds in which R in the general formula (1) represents a linear or branched alkyl group or alkenyl group having 8 to 22 carbon atoms, preferably linear includes compounds having an alkyl or alkenyl group having 8 to 22 carbon atoms.

From the viewpoint of improving the fluidity of the mold composition and the availability of raw materials, the compound represented by the general formula (1) has an alkyl or alkenyl group represented by R in the general formula (1). It includes compounds having 8 or more carbon atoms, preferably 10 or more, and more preferably 12 or more carbon atoms. The compound represented by the general formula (1) is represented by R in the general formula (1) from the viewpoint of improving the fluidity of the mold composition, the storage stability, and the availability of raw materials. It includes compounds in which the number of carbon atoms in the alkyl or alkenyl group is 22 or less, preferably 20 or less, more preferably 18 or less. The compound represented by the general formula (1) is represented by R in the general formula (1) from the viewpoint of improving the fluidity of the mold composition, the storage stability, and the availability of raw materials. It includes compounds in which the alkyl or alkenyl group has 8 to 22 carbon atoms, preferably 10 to 20 carbon atoms, and more preferably 12 to 18 carbon atoms.

In the compound represented by the general formula (1), n in the general formula (1) is 1.2 or more, preferably 1.5 or greater, more preferably 1.8 or greater. In the compound represented by the general formula (1), n in the general formula (1) is 23 from the viewpoints of improving fluidity of the mold composition, storage stability, and raw material availability. The following includes compounds that are preferably 18 or less, more preferably 13 or less. In addition, the compound represented by the general formula (1), from the viewpoint of improving the fluidity of the mold composition, the viewpoint of storage stability, and the viewpoint of raw material availability, the compound represented by the general formula (1) is , 1.2-23, preferably 1.5-18, more preferably 1.8-13.

The content of the compound represented by the general formula (1) with respect to 100 parts by mass of the refractory particles in the mold composition is preferably 0.001 parts by mass or more from the viewpoint of improving the fluidity of the mold composition. 0.003 parts by mass or more is more preferable, and 0.005 parts by mass or more is even more preferable. The content of the compound represented by the general formula (1) with respect to 100 parts by mass of the refractory particles in the mold composition is from the viewpoint of improving the fluidity of the mold composition, from the viewpoint of foam suppression, and from the viewpoint of storage stability. From the point of view and economy, it is preferably 0.1 parts by mass or less, more preferably 0.05 parts by mass or less, and even more preferably 0.02 parts by mass or less. In addition, the content of the compound represented by the general formula (1) with respect to 100 parts by mass of the refractory particles in the mold composition is determined from the viewpoint of improving the fluidity of the mold composition, from the viewpoint of foam suppression, and from the viewpoint of storage stability. From the point of view of sexuality and economy, 0.001 to 0.1 parts by mass is preferable, 0.003 to 0.05 parts by mass is more preferable, and 0.005 to 0.02 parts by mass is even more preferable.

The content of the compound represented by the general formula (1) with respect to a total of 100 parts by mass of the phenolic resin and the curing agent in the mold composition is 0.5 from the viewpoint of improving the fluidity of the mold composition. It is preferably at least 0.75 parts by mass, even more preferably at least 1 part by mass, even more preferably at least 2 parts by mass, and even more preferably at least 3 parts by mass. The content of the compound represented by the general formula (1) with respect to a total of 100 parts by mass of the phenolic resin and the curing agent in the mold composition is from the viewpoint of improving the fluidity of the mold composition, From the viewpoints of storage stability and economy, the amount is preferably 15 parts by mass or less, more preferably 10 parts by mass or less, and even more preferably 5 parts by mass or less. Further, the content of the compound represented by the general formula (1) with respect to a total of 100 parts by mass of the phenolic resin and the curing agent in the mold composition is determined from the viewpoint of improving the fluidity of the mold composition, suppressing foam From the viewpoint of sexuality, storage stability, and economic efficiency, it is preferably 0.5 to 15 parts by mass, more preferably 0.75 to 15 parts by mass, further preferably 1 to 15 parts by mass, and 1 to 10 parts by mass. Part by weight is more preferred, and 1 to 5 parts by weight is even more preferred.

〔fatty acid〕
The fatty acid includes a fatty acid having 8 or more carbon atoms, preferably 10 or more, and more preferably 12 or more carbon atoms from the viewpoint of improving the fluidity of the mold composition and the availability of raw materials. The fatty acid has 22 or less carbon atoms, preferably 20 or less, more preferably 18 or less, from the viewpoints of storage stability, fluidity of the mold composition, and raw material availability. including. In addition, the fatty acid has 8 to 22 carbon atoms, preferably 10 to 20 carbon atoms, more preferably 12 carbon atoms, from the viewpoint of storage stability, the viewpoint of improving the fluidity of the mold composition, and the viewpoint of raw material availability. Contains fatty acids that are ~18.

The fatty acid preferably contains a fatty acid having a melting point of 45°C or less from the viewpoint of storage stability and improving the fluidity of the mold composition.

Examples of the fatty acid include straight-chain aliphatic carboxylic acids, branched-chain aliphatic carboxylic acids, saturated fatty acid carboxylic acids, unsaturated aliphatic carboxylic acids, and specific examples include lauric acid, tridecanoic acid, myristic acid, and pentadecanoic acid. , palmitic acid, margaric acid, stearic acid, nonadecanic acid, oleic acid, linoleic acid, and linolenic acid. The fatty acid preferably contains one or more selected from the group consisting of oleic acid, linolenic acid, and lauric acid, from the viewpoint of improving the fluidity of the mold composition and the availability of raw materials.

The content of the fatty acid with respect to 100 parts by mass of the refractory particles in the mold composition is preferably 0.0005 parts by mass or more, more preferably 0.00075 parts by mass or more, from the viewpoint of improving the fluidity of the mold composition. Preferably, 0.001 parts by mass or more is more preferable. The content of the fatty acid with respect to 100 parts by mass of the refractory particles in the mold composition is determined from the viewpoint of improving the fluidity of the mold composition, the viewpoint of foam suppression, the viewpoint of storage stability, and the viewpoint of economy. , is preferably 0.05 parts by mass or less, more preferably 0.02 parts by mass or less, and even more preferably 0.01 parts by mass or less. In addition, the content of the fatty acid relative to 100 parts by mass of the refractory particles in the mold composition is determined from the viewpoint of improving the fluidity of the mold composition, from the viewpoint of foam suppression, from the viewpoint of storage stability, and from the viewpoint of economic efficiency. From the viewpoint, it is preferably 0.0005 to 0.05 parts by mass, more preferably 0.00075 to 0.02 parts by mass, and even more preferably 0.001 to 0.01 parts by mass.

From the viewpoint of improving the fluidity of the mold composition, the content of the fatty acid in the mold composition is preferably 0.05 parts by mass or more with respect to a total of 100 parts by mass of the phenolic resin and the curing agent. 075 parts by mass or more is more preferable, 0.1 parts by mass or more is still more preferable, 0.25 parts by mass or more is still more preferable, and 0.4 parts by mass or more is still more preferable. The content of the fatty acid in the mold composition with respect to the total of 100 parts by mass of the phenol resin and the curing agent is determined from the viewpoint of improving the fluidity of the mold composition, the viewpoint of foam suppression, and the viewpoint of storage stability. And from the viewpoint of economy, it is preferably 7 parts by mass or less, more preferably 5 parts by mass or less, and even more preferably 3 parts by mass or less. In addition, the content of the fatty acid relative to the total 100 parts by mass of the phenolic resin and the curing agent in the mold composition is from the viewpoint of improving the fluidity of the mold composition, from the viewpoint of foam suppression, and from the viewpoint of storage stability. From the point of view and economical point of view, 0.05 to 7 parts by mass is preferable, 0.075 to 7 parts by mass is more preferable, 0.1 to 7 parts by mass is more preferable, and 0.1 to 5 parts by mass is more preferable. More preferably, 0.1 to 3 parts by mass is even more preferable.

Ratio of the content of the fatty acid to the total content of the compound represented by the general formula (1) and the fatty acid in the template composition (content of the fatty acid/(compound represented by the general formula (1) and the fatty acid)) is preferably 0.05 or more, more preferably 0.08 or more, and still more preferably 0.1 or more, from the viewpoint of improving the fluidity of the mold composition. The ratio of the content of the fatty acid to the total content of the compound represented by the general formula (1) and the fatty acid in the mold composition is determined from the viewpoint of improving the fluidity of the mold composition and from the viewpoint of foam suppression. , storage stability and economy, it is preferably 0.6 or less, more preferably 0.5 or less, and even more preferably 0.4 or less. The ratio of the content of the fatty acid to the total content of the compound represented by the general formula (1) and the fatty acid in the mold composition is determined from the viewpoint of improving the fluidity of the mold composition and from the viewpoint of foam suppression. , from the viewpoint of storage stability and economy, it is preferably 0.05 to 0.6, more preferably 0.08 to 0.5, and even more preferably 0.1 to 0.4.

The mass ratio of the compound represented by the general formula (1) to the fatty acid in the template composition (mass of the compound represented by the general formula (1)/mass of the fatty acid) determines the fluidity of the template composition. is preferably 0.15 or more, more preferably 0.5 or more, and even more preferably 0.9 or more. The mass ratio of the compound represented by the general formula (1) to the fatty acid in the mold composition is determined from the viewpoint of improving the fluidity of the mold composition, the viewpoint of foam suppression, the viewpoint of storage stability, and the viewpoint of economic stability. 100 or less is preferable, 20 or less is more preferable, and 10 or less is still more preferable from a viewpoint of property. The mass ratio of the compound represented by the general formula (1) to the fatty acid in the mold composition is determined from the viewpoint of improving the fluidity of the mold composition, the viewpoint of foam suppression, the viewpoint of storage stability, and the viewpoint of economic stability. From the viewpoint of sexuality, 0.15 to 100 is preferable, 0.5 to 20 is more preferable, and 0.9 to 10 is even more preferable.

[Curing agent]
The curing agent can be used without any particular limitation as long as it cures the phenol resin, but an ester compound is preferable from the viewpoint of improving mold strength. Examples of the ester compound include lactones, organic ester compounds derived from monohydric or polyhydric alcohols having 1 to 10 carbon atoms and organic carboxylic acids having 1 to 10 carbon atoms, carbonate esters, and mixtures thereof. Specifically, lactones include γ-butyrolactone, propionolactone, ε-caprolactone, and the like. Organic ester compounds include ethyl formate, ethylene glycol diacetate, ethylene glycol monoacetate, triethylene glycol diacetate, triethylene glycol monoacetate, ethyl acetoacetate, dimethyl succinate, dimethyl glutarate, dimethyl adipate, triacetin, 2 dimethyl-ethylsuccinate, dimethyl 2-methylglutarate, dimethyl 2-methyladipate, etc. Carbonic acid esters include ethylene carbonate, propylene carbonate, and the like. Among these, γ-butyrolactone, propionlactone, ε-caprolactone, ethyl formate, ethylene glycol diacetate, ethylene glycol monoacetate, triacetin, One or more selected from propylene carbonate, dimethyl glutarate, dimethyl adipate, triethylene glycol diacetate, dimethyl succinate, dimethyl 2-ethylsuccinate, dimethyl 2-methylglutarate, and dimethyl 2-methyladipate are preferred. Also, it is preferred to use methyl formate in the gas-curable mold making process using an ester compound.

The content of the curing agent with respect to 100 parts by mass of the phenol resin in the mold composition is preferably 10 parts by mass or more, more preferably 15 parts by mass or more, from the viewpoint of improving mold strength and curing speed. Preferably, it is 20 parts by mass or more, and even more preferably 25 parts by mass or more. The content of the curing agent with respect to 100 parts by mass of the phenolic resin in the mold composition is preferably 70 parts by mass or less from the viewpoint of improving the mold strength, improving the curing speed, and from the viewpoint of economy. It is more preferably 50 parts by mass or less, and even more preferably 45 parts by mass or less. The content of the curing agent with respect to 100 parts by mass of the phenolic resin in the mold composition is preferably 10 to 70 parts by mass from the viewpoint of improving the mold strength, improving the curing speed, and from the viewpoint of economy. 15 to 60 parts by weight is more preferred, 20 to 50 parts by weight is even more preferred, and 25 to 45 parts by weight is even more preferred.

[Other ingredients]
The template composition preferably contains resorcinol from the viewpoint of improving the working environment. Since resorcinol has the function of capturing formaldehyde, it is possible to reduce formaldehyde contained in thermal decomposition gas during pouring, after pouring, and during demolding.

The content of resorcinol in the mold composition is preferably 0.001% by mass or more, more preferably 0.003% by mass or more, more preferably 0.005% by mass, from the viewpoint of reducing formaldehyde and improving the mold strength. % or more is more preferable. The content of resorcinol in the mold composition is preferably 0.06% by mass or less, more preferably 0.04% by mass or less, from the viewpoints of reducing formaldehyde, improving mold strength, and economic efficiency. , 0.02% by mass or less is more preferable. Further, the content of resorcinol in the mold composition is preferably 0.001 to 0.06% by mass, preferably 0.003 to 0.006% by mass, from the viewpoints of reducing formaldehyde, improving mold strength, and economic efficiency. 0.04% by mass is more preferable, and 0.005 to 0.02% by mass is even more preferable.

The template composition may contain other components within a range that does not impair the effects of the present invention. Examples of other components include solvents such as water, alcohols, ether alcohols, and glycols. Among these, one or more selected from the group consisting of water, alcohols, ether alcohols, and glycols is preferable from the viewpoint of the tactile sensation of kneaded sand and the viewpoint of odor suppression. Alcohols, diethylene glycol, triethylene glycol, polyethylene glycol, dipropylene glycol, tripropylene glycol, and one or more selected from the group consisting of benzyl alcohol are more preferable, and from the group consisting of methanol, ethanol, diethylene glycol, and triethylene glycol One or more selected are more preferable, and water and triethylene glycol are even more preferable.

The content of the solvent in the mold composition is preferably 0.01% by mass or more, more preferably 0.02% by mass or more, and even more preferably 0.03% by mass or more, from the viewpoint of uniformly mixing the raw materials. . The content of the solvent in the mold composition is preferably 0.9% by mass or less, more preferably 0.8% by mass or less, from the viewpoint of uniformly mixing the raw materials, the viewpoint of odor suppression, and the viewpoint of economy. Preferably, 0.7% by mass or less is more preferable. The content of the solvent in the mold composition is preferably 0.01 to 0.9% by mass, preferably 0.02 to 0.9% by mass, from the viewpoint of uniform mixing of raw materials, suppression of odor, and economic efficiency. 0.8 mass % is more preferred, and 0.03 to 0.7 mass % is even more preferred.

<Curing agent composition for mold making>
The mold-forming curing agent composition (hereinafter also simply referred to as curing agent composition) of the present embodiment contains the curing agent, the compound represented by the general formula (1), and the fatty acid. When the compound represented by the general formula (1) or the fatty acid having 8 to 22 carbon atoms is added to the binder composition for mold molding, air bubbles or aggregates are generated, but the general formula ( When the compound represented by 1) and the fatty acid having 8 to 22 carbon atoms are contained in the curing agent composition, the fluidity of the mold composition can be improved while suppressing air bubbles and aggregates.

The content of the compound represented by the general formula (1) in the curing agent composition is preferably 1% by mass or more, more preferably 1.5% by mass or more, from the viewpoint of improving the fluidity of the mold composition. , more preferably 2% by mass or more. The content of the compound represented by the general formula (1) in the curing agent composition is determined from the viewpoints of improving fluidity of the mold composition, storage stability, low-temperature stability, and economic efficiency. Therefore, it is preferably 10% by mass or less, more preferably 7% by mass or less, and even more preferably 5% by mass or less. In addition, the content of the compound represented by the general formula (1) in the curing agent composition is determined from the viewpoint of improving the fluidity of the mold composition, from the viewpoint of storage stability, from the viewpoint of low-temperature stability, and from the viewpoint of economic efficiency. From the viewpoint of , 1 to 10% by mass is preferable, 1.5 to 7% by mass is more preferable, and 2 to 5% by mass is even more preferable.

From the viewpoint of improving the fluidity of the mold composition, the content of the fatty acid in the curing agent composition is preferably 0.1% by mass or more, more preferably 0.2% by mass or more, and more preferably 0.3% by mass. The above is more preferable. The content of the fatty acid in the curing agent composition is preferably 6% by mass or less from the viewpoints of improving fluidity of the mold composition, storage stability, low-temperature stability, and economy. , 5% by mass or less is more preferable, 4% by mass or less is even more preferable, and 3% by mass or less is even more preferable. In addition, the content of the compound represented by the general formula (1) in the curing agent composition is determined from the viewpoint of improving the fluidity of the mold composition, from the viewpoint of storage stability, from the viewpoint of low-temperature stability, and from the viewpoint of economic efficiency. From the viewpoint of , 0.1 to 6% by mass is preferable, 0.2 to 5% by mass is more preferable, 0.3 to 4% by mass is still more preferable, and 0.3 to 3% by mass is even more preferable.

From the viewpoint of improving mold strength, the content of the curing agent in the curing agent composition is preferably 60% by mass or more, more preferably 70% by mass or more, still more preferably 80% by mass or more, and 85% by mass or more. is even more preferred. The content of the curing agent in the curing agent composition is preferably 99% by mass or less, more preferably 98% by mass or less, and further preferably 97% by mass or less, from the viewpoint of improving mold strength and economic efficiency. preferable. Further, the content of the curing agent in the curing agent composition is preferably 60 to 99% by mass, more preferably 70 to 98% by mass, from the viewpoint of improving the mold strength and from the viewpoint of economy. 97% by mass is more preferred, and 85 to 97% by mass is even more preferred.

Ratio of the content of the fatty acid to the total content of the compound represented by the general formula (1) and the fatty acid in the curing agent composition (content of the fatty acid / (content represented by the general formula (1) From the viewpoint of improving the fluidity of the mold composition, the total content of the compound and the fatty acid)) is preferably 0.05 or more, more preferably 0.08 or more, and still more preferably 0.1 or more. The ratio of the content of the fatty acid to the total content of the compound represented by the general formula (1) and the fatty acid in the curing agent composition is determined from the viewpoint of improving the fluidity of the mold composition, From the viewpoints of storage stability and economy, it is preferably 0.6 or less, more preferably 0.5 or less, and even more preferably 0.4 or less. The ratio of the content of the fatty acid to the total content of the compound represented by the general formula (1) and the fatty acid in the curing agent composition is determined from the viewpoint of improving the fluidity of the mold composition, 0.05 to 0.6 is preferred, 0.08 to 0.5 is more preferred, and 0.1 to 0.4 is even more preferred from the viewpoints of storage stability and economy.

[Other ingredients]
From the viewpoint of improving the working environment, the curing agent composition preferably contains resorcinol.

From the viewpoint of reducing formaldehyde and improving mold strength, the content of resorcinol in the curing agent composition is preferably 1% by mass or more, more preferably 1.5% by mass or more, and 2% by mass or more. More preferred. The content of resorcinol in the curing agent composition is preferably 20% by mass or less, more preferably 15% by mass or less, and 10% by mass from the viewpoints of reducing formaldehyde, improving mold strength, and economic efficiency. % or less is more preferable, and 5% by mass or less is even more preferable. Further, the content of resorcinol in the curing agent composition is preferably 1 to 20% by mass, more preferably 1.5 to 15% by mass, from the viewpoints of reducing formaldehyde, improving mold strength, and economic efficiency. is more preferable, 2 to 10% by mass is more preferable, and 2 to 5% by mass is even more preferable.

The curing agent composition may contain other components within a range that does not impair the effects of the present invention. Examples of other components include solvents such as water, alcohols, ether alcohols, and glycols. Among these, one or more selected from the group consisting of alcohols, ether alcohols, and glycols is used from the viewpoint of compatibility between the curing agent and the phenol resin, the feel of the mold composition, and the suppression of odor. More preferably, one or more selected from the group consisting of alcohols having 1 to 3 carbon atoms, diethylene glycol, triethylene glycol, polyethylene glycol, dipropylene glycol, tripropylene glycol, and benzyl alcohol, methanol, ethanol, diethylene glycol, At least one selected from the group consisting of triethylene glycol and benzyl alcohol is more preferred, and triethylene glycol is even more preferred.

The content of the solvent in the curing agent composition is preferably 1% by mass or more, more preferably 2% by mass or more, and even more preferably 3% by mass or more, from the viewpoint of uniformly mixing the raw materials. The content of the solvent in the curing agent composition is preferably 30% by mass or less, more preferably 25% by mass or less, more preferably 20% by mass or less, from the viewpoints of uniform mixing of raw materials, suppression of odor, and economic efficiency. % by mass or less is more preferable. The content of the solvent in the curing agent composition is preferably 1 to 30% by mass, more preferably 2 to 25% by mass, from the viewpoints of uniform mixing of raw materials, suppression of odor, and economic efficiency. , 3 to 20% by mass is more preferable.

<Method for manufacturing mold composition>
The mold composition can be produced by a known method. The method for producing the mold composition includes a mixing step of mixing the refractory particles, the binder composition for mold molding containing the phenol resin, and the curing agent composition. can be exemplified.

[Binder composition for mold making]
The content of the water-soluble phenolic resin in the binder composition for mold making (hereinafter sometimes simply referred to as the binder composition) is preferably 10% by mass or more from the viewpoint of improving the strength of the mold. , more preferably 20% by mass or more, still more preferably 30% by mass or more, and even more preferably 40% by mass or more. From the viewpoint of improving mold strength and improving workability, the content of the water-soluble phenol resin in the binder composition is preferably 95% by mass or less, more preferably 80% by mass or less, and 70% by mass or less. % by mass or less is more preferable, and 60% by mass or less is even more preferable. Further, the content of the water-soluble phenol resin in the binder composition is preferably 10 to 95% by mass, more preferably 20 to 80% by mass, from the viewpoint of improving mold strength and improving workability. More preferably 30 to 70% by mass, even more preferably 40 to 60% by mass.

[Other ingredients]
The binder composition may further contain additives such as water, silane coupling agents, urea, surfactants, and alcohols to the extent that the effects of the present embodiment are not impaired. In addition, it is preferable that the binder composition contains a silane coupling agent because the final strength of the resulting mold can be further improved. Examples of the silane coupling agent include γ-(2-amino)propylmethyldimethoxysilane, γ-aminopropyltrimethoxysilane, γ-aminopropyltriethoxysilane, γ-glycidoxypropyltrimethoxysilane, N- β-(aminoethyl)γ-aminopropylmethyldimethoxysilane and the like. The content of the silane coupling agent in the binder composition is preferably 0.1 to 5% by mass, more preferably 0.3 to 1% by mass, from the viewpoint of improving mold strength.

In the mixing step, as a method for mixing each raw material, a known general method can be used, for example, a method of adding each raw material by a batch mixer and kneading, or a method of supplying each raw material to a continuous mixer and kneading. method.

<Mold manufacturing method>
In the mold manufacturing method of the present embodiment, the mold can be manufactured by using the conventional mold manufacturing process as it is. As a preferred mold manufacturing method, there is a mold manufacturing method including a curing step of packing the mold composition into a mold and curing the mold composition.

In relation to the above-described embodiments, the present invention further discloses the following embodiments.
<1>
A mold composition containing refractory particles, a phenolic resin, a curing agent, a compound represented by the following general formula (1), and a fatty acid having 8 to 22 carbon atoms.
RO—(CH ₂ CH ₂ O)n—H (1)
(In the general formula (1), R represents a linear or branched alkyl group or alkenyl group having 8 to 22 carbon atoms, n represents the average number of added moles, and a number of 1.2 to 23 show.)
<2>
The mold composition according to <1>, wherein the content of the phenol resin is 0.1 parts by mass or more and 5 parts by mass or less with respect to 100 parts by mass of the refractory particles.
<3>
The mold composition according to <1> or <2>, wherein the content of the phenol resin is 0.3 parts by mass or more and 1 part by mass or less with respect to 100 parts by mass of the refractory particles.
<4>
The mold composition according to any one of <1> to <3>, wherein the content of the curing agent is 10 parts by mass or more and 70 parts by mass or less with respect to 100 parts by mass of the phenolic resin.
<5>
The mold composition according to any one of <1> to <4>, wherein the content of the curing agent is 25 parts by mass or more and 45 parts by mass or less with respect to 100 parts by mass of the phenolic resin.
<6>
The curing agent includes γ-butyrolactone, propionlactone, ε-caprolactone, ethyl formate, ethylene glycol diacetate, ethylene glycol monoacetate, triacetin, propylene carbonate, dimethyl glutarate, dimethyl adipate, dimethyl succinate, and triethylene glycol diacetate. The template composition according to any one of <1> to <5>, comprising at least one selected from acetate, dimethyl 2-ethylsuccinate, dimethyl 2-methylglutarate, and dimethyl 2-methyladipate.
<7>
Any of <1> to <6>, wherein the content of the compound represented by the general formula (1) is 0.001 parts by mass or more and 0.1 parts by mass or less with respect to 100 parts by mass of the refractory particles 10. The mold composition according to 1.
<8>
Any of <1> to <7>, wherein the content of the compound represented by the general formula (1) is 0.005 parts by mass or more and 0.02 parts by mass or less with respect to 100 parts by mass of the refractory particles 10. The mold composition according to 1.
<9>
Any of <1> to <8>, wherein the content of the compound represented by the general formula (1) is 1% by mass or more and 10% by mass or less with respect to a total of 100 parts by mass of the phenol resin and the curing agent. The described template composition.
<10>
Any of <1> to <9>, wherein the content of the compound represented by the general formula (1) is 1% by mass or more and 5% by mass or less with respect to a total of 100 parts by mass of the phenol resin and the curing agent. The described template composition.
<11>
In the compound represented by the general formula (1), R in the general formula (1) represents a straight-chain alkyl group or alkenyl group having 10 to 20 carbon atoms, and n is a number of 1.8 to 13. The template composition according to any one of <1> to <10>, which contains a compound showing
<12>
The mold composition according to any one of <1> to <11>, wherein the content of the fatty acid relative to 100 parts by mass of the refractory particles is 0.001 part by mass or more and 0.01 part by mass or less.
<13>
The mold composition according to any one of <1> to <12>, wherein the content of the fatty acid is 0.25 parts by mass or more and 5 parts by mass or less with respect to a total of 100 parts by mass of the phenol resin and the curing agent.
<14>
The mold composition according to any one of <1> to <13>, wherein the content of the fatty acid is 0.4 parts by mass or more and 3 parts by mass or less with respect to a total of 100 parts by mass of the phenol resin and the curing agent.
<15>
The template composition according to any one of <1> to <14>, wherein the fatty acid has a melting point of 45°C or lower.
<16>
The template composition according to any one of <1> to <15>, wherein the fatty acid contains one or more selected from the group consisting of oleic acid, linolenic acid, and lauric acid.
<17>
<1> to <16>, wherein the ratio of the content of the fatty acid to the total content of the compound represented by the general formula (1) and the fatty acid is 0.05 or more and 0.6 or less. template composition.
<18>
<1> to <17>, wherein the ratio of the content of the fatty acid to the total content of the compound represented by the general formula (1) and the fatty acid is 0.1 or more and 0.4 or less. template composition.
<19>
A curing agent composition for mold making, comprising a curing agent, a compound represented by the following general formula (1), and a fatty acid having 8 to 22 carbon atoms.
RO—(CH ₂ CH ₂ O)n—H (1)
(In the general formula (1), R represents a linear or branched alkyl group or alkenyl group having 8 to 22 carbon atoms, n represents the average number of added moles, and a number of 1.2 to 23 show.)
<20>
The curing agent composition for mold making according to <19>, wherein the content of the curing agent in the curing agent composition is 80% by mass or more and 97% by mass or less.
<21>
The curing agent composition for mold formation according to <19> or <20>, wherein the content of the curing agent in the curing agent composition is 85% by mass or more and 97% by mass or less.
<22>
The curing agent includes γ-butyrolactone, propionlactone, ε-caprolactone, ethyl formate, ethylene glycol diacetate, ethylene glycol monoacetate, triacetin, propylene carbonate, dimethyl glutarate, dimethyl adipate, dimethyl succinate, and triethylene glycol diacetate. The mold-making curing agent composition according to any one of <19> to <21>, comprising at least one selected from acetate, dimethyl 2-ethylsuccinate, dimethyl 2-methylglutarate, and dimethyl 2-methyladipate. thing.
<23>
The curing agent composition for mold making according to any one of <19> to <22>, wherein the content of the compound represented by the general formula (1) is 1% by mass or more and 10% by mass or less.
<24>
The curing agent composition for mold making according to any one of <19> to <23>, wherein the content of the compound represented by the general formula (1) is 2% by mass or more and 5% by mass or less.
<25>
In the compound represented by the general formula (1), R in the general formula (1) represents a straight-chain alkyl group or alkenyl group having 10 to 20 carbon atoms, and n is a number of 1.8 to 13. The curing agent composition for mold formation according to any one of <19> to <24>, comprising a compound showing
<26>
The curing agent composition for mold making according to any one of <19> to <25>, wherein the fatty acid content is 0.1% by mass or more and 6% by mass or less.
<27>
The curing agent composition for mold making according to any one of <19> to <26>, wherein the content of the fatty acid is 0.3% by mass or more and 3% by mass or less.
<28>
The casting mold curing agent composition according to any one of <19> to <27>, wherein the fatty acid has a melting point of 45° C. or lower.
<29>
The curing agent composition for mold making according to any one of <19> to <28>, wherein the fatty acid contains one or more selected from the group consisting of oleic acid, linolenic acid and lauric acid.
<30>
Any one of <19> to <29>, wherein the ratio of the content of the fatty acid to the total content of the compound represented by the general formula (1) and the fatty acid is 0.05 or more and 0.6 or less. Curing agent composition for mold making.
<31>
Any one of <19> to <30>, wherein the ratio of the content of the fatty acid to the total content of the compound represented by the general formula (1) and the fatty acid is 0.1 or more and 0.4 or less. Curing agent composition for mold making.
<32>
The curing agent composition for mold making according to any one of <19> to <31>, which further contains resorcinol and has a resorcinol content of 2% by mass or more and 10% by mass or less.
<33>
The curing agent composition for mold making according to any one of <19> to <32>, which further contains resorcinol and has a resorcinol content of 2% by mass or more and 5% by mass or less.
<34>
A mold composition comprising a step of mixing refractory particles, a binder composition for mold molding containing a phenol resin, and the curing agent composition for mold molding according to any one of <19> to <33>. Production method.

Examples and the like specifically showing the present invention will be described below.

<Raw material evaluation method>
[Weight average molecular weight (Mw) of phenolic resin]
(a) Sample preparation: Add the same weight of ion-exchanged water to the sample, add 0.1% by weight of H ₂ SO ₄ for neutralization, separate the formed precipitate by filtration, wash with water, and dry. This is dissolved in tetrahydrofuran (THF) to prepare a sample for GPC.
(b) Column: Guard column TSX (manufactured by Toyo Soda Kogyo Co., Ltd.) 1 HXL (6.5 mm φ × 4 cm), 1 TSK3000HXL (7.8 mm φ × 30 cm), and 1 TSK2500HXL (7.8 mm φ × 30 cm) use. From the inlet side, connect in order of guard column-3000HXL-2500HXL.
(c) Standard material: Polystyrene (manufactured by Toyo Soda Kogyo Co., Ltd.)
(d) Eluent: THF (flow rate: 1 cm ³ /min)
(e) Column temperature: 25°C
(f) Detector: UV spectrophotometer (quantification at the wavelength of the maximum peak of UV absorption of phenol)
(g) Division method for molecular weight calculation: time division (2 sec)

<Method for measuring average particle size of refractory particles>
Measured using 850, 600, 425, 300, 212, 150, 106, 75, and 53 μm sieves based on the method specified in JIS Z2601 (1993) “Testing methods for foundry sand” Annex 2, and accumulated mass Let the particle size of 50% be the average particle size.

<Production of raw materials>
[Production of binder composition]
An aqueous solution obtained by mixing 10 mol of phenol, a 50% by mass aqueous potassium hydroxide solution (0.40 times the mol of phenol), and a 50% by mass aqueous sodium hydroxide solution (0.40 times the mol of phenol), and , water was added, and 92 mass % paraformaldehyde (2.00 times mol with respect to phenol) was added. A polycondensation reaction was carried out at 80° C., and the reaction was continued until the weight average molecular weight of the phenolic resin reached 2,000. Next, 0.5 part by mass of γ-glycidoxypropyltrimethoxysilane was added to 100 parts by mass of the reaction solution to obtain a binder composition containing a phenol resin (weight average molecular weight: 2000) (solid content: 49.5 parts by mass). 1 to 50% by mass) was obtained.

[Production of refractory particles]
[Production of refractory particles 1]
0.26% by mass of a curing agent (96% by mass of γ-butyrolactone, 4% by mass of resorcinol) and 1.3% by mass of a water-soluble phenolic resin composition are added to 100% by mass of Fremantle sand (natural silica sand) to form a mold composition. got stuff Using a mold made using the mold composition, the S/M ratio was set to 3.5 (S/M ratio represents the ratio between the mass of the mold and the mass of the casting), and the casting material FC250 was heated at 1400 ° C. I poured hot water. Foundry sand recovered from the mold after casting was mixed with Fremantle sand (natural silica sand) to a concentration of 5% by mass, and reclaimed using an M-type rotary reclaimer manufactured by Nippon Chuzo Co., Ltd. The above steps were repeated five times to obtain refractory particles 1 having an average particle size of 378 μm.

[Production of refractory particles 2]
Refractory particles 1 were produced in the same manner except that Fremantle sand (natural silica sand: average particle size 528 μm) added to the recovered foundry sand was 10% by mass. Particle 2 was obtained.

[Production of refractory particles 3]
Refractory particles 3 having an average particle size of 348 μm were obtained by the same production method as in the production of refractory particles 1 except that the Fremantle sand (natural silica sand) added to the recovered foundry sand was not added. .

[Production of refractory particles 4]
Refractory particles 4 having an average particle diameter of 396 μm were produced in the same manner as in the production of refractory particles 1 except that Fremantle sand was changed to Espearl #40L (manufactured by Yamakawa Sangyo Co., Ltd.: average particle diameter 406 μm). Obtained.

[Production of refractory particles 5]
In the production of refractory particles 1, the same production method was used except that the Fremantle sand was changed to Espearl #40L (manufactured by Yamakawa Sangyo Co., Ltd.) and Espearl #40L added to the recovered foundry sand was changed to 10% by mass. Refractory particles 5 having an average particle size of 398 µm were obtained.

[Production of refractory particles 6]
In the production of refractory particles 1, the production method was the same except that Fremantle sand was changed to Espearl #40L (manufactured by Yamakawa Sangyo Co., Ltd.) and Espearl #40L added to the recovered foundry sand was not added. Refractory particles 6 having an average particle size of 390 μm were obtained.

[Refractory particles 7]
Fremantle sand (natural silica sand: average particle size 528 μm) was used as the refractory particles 7 .

[Refractory particles 8]
Espearl #40L (manufactured by Yamakawa Sangyo Co., Ltd.) was used as the refractory particles 8 .

<Manufacture of mold composition>
[Examples 1-1 to 1-13, Comparative Examples 1-1 to 1-6]
Add 100 parts by mass of refractory particles 1 and 0.26 parts by mass of the curing agent composition shown in Table 1, and knead for 40 seconds using a kneader (desktop mixer KM-300, Aikosha Seisakusho Co., Ltd.). Kneaded. Thereafter, 1.3 parts by mass of a binder composition shown in Table 1 was added and kneaded for 40 seconds to obtain a mold composition.

[Example 1-14]
100 parts by mass of refractory particles 1, 0.0091 parts by mass of the compound of formula (1) (R: lauryl, n=5), 0.0026 parts by mass of oleic acid, and 0 of the curing agent composition shown in Table 1 .26 parts by mass were added and kneaded for 40 seconds using a kneader (desktop mixer KM-300, Aikosha Seisakusho Co., Ltd.). Thereafter, 1.3 parts by mass of a binder composition shown in Table 1 was added and kneaded for 40 seconds to obtain a mold composition.

[Examples 1-15 to 1-21, Comparative Examples 1-7 to 1-13]
The same procedure as in Example 1-1 was performed except that the refractory particles, the binder composition and the curing agent composition shown in Table 2 were used. Examples 1-15 to 1-21 and Comparative Examples 1-7 to 1-1 A template composition of -13 was obtained.

〔evaluation〕
Using the mold compositions of Examples 1-1 to 1-21 and Comparative Examples 1-1 to 1-13, fluidity and fillability were evaluated by the following methods. Evaluation results are shown in Tables 1 and 2.

[Liquidity evaluation]
The mold composition immediately after kneading is filled into a standing cylindrical PVC pipe (φ50 mm × 300 mmH) until peaks are formed on the upper surface of the PVC pipe, and the sand on the peaks on the upper surface is scraped off. The cylinder was lifted and the width mm of the expanded mold composition was measured. The higher the value, the better the fluidity.

[Filling density evaluation]
The mass of the mold composition in the PVC pipe was measured and calculated from the volume of the PVC pipe. The higher the value, the higher the packing density and the better the fluidity.

[Template evaluation]
Using the mold compositions of Example 1-1 and Comparative Example 1-1, molds were produced by the following method. The mold composition immediately after kneading was passed through a sieve having a metal mesh with an opening of 3.35 mm and a wire diameter of 1.27 mm, and then filled in a wooden mold for evaluating the smoothness of the mold surface. A cross-sectional view of the wooden pattern is shown in FIG. The mold composition was filled higher than the upper surface of the wooden mold, and immediately the excess mold composition on the upper surface of the wooden mold was scraped off to mold the mold. After the mold composition in the wooden mold had hardened, the mold was removed from the wooden mold and the surface smoothness was visually observed. The appearance of the mold according to Example 1-1 manufactured is shown in FIG. 2, and the appearance of the mold according to Comparative Example 1-1 is shown in FIG. Since the mold composition of Example 1-1 has improved fluidity and packing density compared to the mold composition of Comparative Example 1-1, the mold according to Example 1-1 is similar to that of Comparative Example 1-1. surface smoothness is higher than that of the mold according to As a result, mold repair can be reduced, and casting quality is greatly improved.

[Casting quality evaluation]
A casting quality evaluation method will be described with reference to the drawings. First, a master mold was produced using the mold composition of Comparative Example 1-1. FIG. 4 is a diagram schematically showing a cross section of the main mold 1, wherein reference numeral 11 indicates an inner wall of the main mold 1, and reference numeral 12 indicates a cross section of the main mold 1. As shown in FIG. In this master mold 1, a mold 2 according to Example 1-1 or Comparative Example 1-1 prepared for mold evaluation was placed. FIG. 5 is a schematic diagram showing a cross section of the mold 2 installed in the master mold 1. As shown in FIG. Next, as shown in FIG. 6, 17 kg of molten metal material FC200 was poured at 1400° C. into the main mold 1 in which the mold 2 was installed to prepare a casting 3 . 7 shows the cross section 3 of the casting 3 and the inner wall of the casting 3 (the mold 2 has 31 is a schematic diagram showing a contact surface) 31. FIG. FIG. 8 shows an appearance photograph of the inner wall 11 of the casting 3 according to Example 1-1, and FIG. 9 shows an appearance photograph of the inner wall 11 of the casting 3 according to Comparative Example 1-1. Since the mold composition of Example 1-1 has higher fluidity, improved packing density, and higher mold smoothness than the mold composition of Comparative Example 1-1, the inner wall 11 of the casting 3 according to Example 1-1 has higher smoothness than the surface of the inner wall 11 of the casting 3 according to Comparative Example 1-1. Therefore, the repair of castings can be reduced, and the quality of castings can be greatly improved.

The mold composition according to the example is superior in fluidity and packing density compared to the mold composition according to the comparative example. In particular, as shown in Comparative Examples 1-1 and 1-2, Comparative Examples 1-3 and 1-4, even if the content of the compound of the general formula (1) and the fatty acid increases, the fluidity and Although the packing density is not improved, as shown in Examples 1-1 to 1-14, the combined use of the compound of formula (1) and the fatty acid improves fluidity and packing density.

[Examples 2-1 to 2-12, Comparative Example 2-1]
As shown in Table 3, the curing agent composition used in Examples 1-1 to 1-12 and the binder composition used in Example 1-13 were used to evaluate foaming and storage stability. rice field.

[Evaluation of foaming]
A 50 ml transparent glass container was charged with the binder composition or curing agent composition shown in the table, and shaken and stirred for 10 seconds using a touch mixer MT-31 manufactured by Yamato Scientific Co., Ltd. After 1 minute, the presence or absence of air bubbles was visually confirmed.

[Storage stability]
After storage at 25° C. for 3 days, the presence or absence of liquid separation, insoluble matter and turbidity was visually confirmed. Table 3 shows the evaluation results.

The curing agent compositions of Examples 2-1 to 2-12, in which the compound of formula (1) and fatty acid were blended in the curing agent composition, were compared with the compound of formula (1) and fatty acid blended in the binder composition. Compared to the binder composition of Example 2-1, no air bubbles are generated and the storage stability is excellent.

Claims

A mold composition containing refractory particles, a phenolic resin, a curing agent, a compound represented by the following general formula (1), and a fatty acid having 8 to 22 carbon atoms.
RO—(CH 2 CH 2 O)n—H (1)
(In the general formula (1), R represents a linear or branched alkyl group or alkenyl group having 8 to 22 carbon atoms, n represents the average number of added moles, and a number of 1.2 to 23 show.)
The mold composition according to claim 1, wherein the content of the phenol resin is 0.1 parts by mass or more and 5 parts by mass or less with respect to 100 parts by mass of the refractory particles.
The mold according to claim 1 or 2, wherein the content of the compound represented by the general formula (1) is 0.001 parts by mass or more and 0.1 parts by mass or less with respect to 100 parts by mass of the refractory particles. Composition.
In the compound represented by the general formula (1), R in the general formula (1) represents a straight-chain alkyl group or alkenyl group having 10 to 20 carbon atoms, and n is a number of 1.8 to 13. The template composition according to any one of claims 1 to 3, comprising a compound that exhibits
The mold composition according to any one of claims 1 to 4, wherein the content of the fatty acid is 0.0005 parts by mass or more and 0.05 parts by mass or less with respect to 100 parts by mass of the refractory particles.
The ratio of the content of the fatty acid to the total content of the compound represented by the general formula (1) and the fatty acid is 0.05 or more and 0.6 or less, according to any one of claims 1 to 5. template composition.
A curing agent composition for mold making, comprising a curing agent, a compound represented by the following general formula (1), and a fatty acid having 8 to 22 carbon atoms.
RO—(CH 2 CH 2 O)n—H (1)
(In the general formula (1), R represents a linear or branched alkyl group or alkenyl group having 8 to 22 carbon atoms, n represents the average number of added moles, and a number of 1.2 to 23 show.)
The curing agent composition for mold making according to claim 7, wherein the content of the fatty acid is 0.1% by mass or more and 6% by mass or less.
The casting mold curing agent composition according to claim 7 or 8, wherein the fatty acid contains a fatty acid having a melting point of 45°C or lower.
The casting mold curing agent composition according to any one of claims 7 to 9, wherein the fatty acid contains one or more selected from the group consisting of oleic acid, linolenic acid, and lauric acid.
The curing agent composition for mold making according to any one of claims 7 to 10, wherein the content of the compound represented by the general formula (1) is 1% by mass or more and 10% by mass or less.
The ratio of the content of the fatty acid to the total content of the compound represented by the general formula (1) and the fatty acid is 0.05 or more and 0.6 or less according to any one of claims 7 to 11. Curing agent composition for mold making.
A mold composition comprising a step of mixing refractory particles, a mold forming binder composition containing a phenolic resin, and the mold forming curing agent composition according to any one of claims 7 to 12. Production method.
In the compound represented by the general formula (1), R in the general formula (1) represents a straight-chain alkyl group or alkenyl group having 10 to 20 carbon atoms, and n is a number of 1.8 to 13. 14. The method for producing a template composition according to claim 13, comprising a compound showing
The method for producing a mold composition according to claim 13 or 14, wherein the fatty acid contains a fatty acid having a melting point of 45°C or lower.
The method for producing a template composition according to any one of claims 13 to 15, wherein the fatty acid contains one or more selected from the group consisting of oleic acid, linolenic acid, and lauric acid.