WO2020070819A1 - Binder composition for forming mold - Google Patents

Binder composition for forming mold

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Publication number
WO2020070819A1
WO2020070819A1 PCT/JP2018/037004 JP2018037004W WO2020070819A1 WO 2020070819 A1 WO2020070819 A1 WO 2020070819A1 JP 2018037004 W JP2018037004 W JP 2018037004W WO 2020070819 A1 WO2020070819 A1 WO 2020070819A1
Authority
WO
WIPO (PCT)
Prior art keywords
mold
mass
binder composition
composition
viewpoint
Prior art date
Application number
PCT/JP2018/037004
Other languages
French (fr)
Japanese (ja)
Inventor
宏明 青沼
俊樹 松尾
友希 猪狩
Original Assignee
花王株式会社
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by 花王株式会社 filed Critical 花王株式会社
Priority to PCT/JP2018/037004 priority Critical patent/WO2020070819A1/en
Priority to JP2020550999A priority patent/JP6971412B2/en
Priority to CN201880093796.6A priority patent/CN112203784A/en
Publication of WO2020070819A1 publication Critical patent/WO2020070819A1/en

Links

Classifications

    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B22—CASTING; POWDER METALLURGY
    • B22C—FOUNDRY MOULDING
    • B22C1/00—Compositions of refractory mould or core materials; Grain structures thereof; Chemical or physical features in the formation or manufacture of moulds
    • B22C1/02—Compositions of refractory mould or core materials; Grain structures thereof; Chemical or physical features in the formation or manufacture of moulds characterised by additives for special purposes, e.g. indicators, breakdown additives
    • B22C1/10—Compositions of refractory mould or core materials; Grain structures thereof; Chemical or physical features in the formation or manufacture of moulds characterised by additives for special purposes, e.g. indicators, breakdown additives for influencing the hardening tendency of the mould material
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B22—CASTING; POWDER METALLURGY
    • B22C—FOUNDRY MOULDING
    • B22C1/00—Compositions of refractory mould or core materials; Grain structures thereof; Chemical or physical features in the formation or manufacture of moulds
    • B22C1/16—Compositions of refractory mould or core materials; Grain structures thereof; Chemical or physical features in the formation or manufacture of moulds characterised by the use of binding agents; Mixtures of binding agents
    • B22C1/20—Compositions of refractory mould or core materials; Grain structures thereof; Chemical or physical features in the formation or manufacture of moulds characterised by the use of binding agents; Mixtures of binding agents of organic agents
    • B22C1/22—Compositions of refractory mould or core materials; Grain structures thereof; Chemical or physical features in the formation or manufacture of moulds characterised by the use of binding agents; Mixtures of binding agents of organic agents of resins or rosins

Definitions

  • the present invention relates to a binder composition for mold making.
  • an acid-curable mold is a refractory particle such as silica sand, a mold-forming binder composition containing an acid-curable resin, and a curing agent composition containing sulfonic acid, sulfuric acid, phosphoric acid, and the like.
  • the obtained kneading sand is filled in a prototype such as a wooden mold, and the acid-curable resin is cured to produce the mixture.
  • Furan resin and phenol resin are used as the acid-curable resin.
  • Furfuryl alcohol, furfuryl alcohol / urea / formaldehyde resin, furfuryl alcohol / formaldehyde resin, furfuryl alcohol / phenol / Formaldehyde resins and other known modified furan resins are used.
  • Such a method of manufacturing a mold allows for a high degree of freedom in molding work, and because of the excellent thermal properties of the mold, high-quality castings can be manufactured. Therefore, machine parts, construction machine parts, automobile parts, etc. It is widely used when casting castings.
  • furfuryl alcohol is widely used as a component of acid-curable resins such as furan resins.
  • furfuryl alcohol is produced through a process of hydrolyzing and dehydrating a raw material composed of agricultural by-products such as corn core to obtain furfural, and a process of hydrogenating furfural, and the production cost is relatively high.
  • a large amount of residue is generated as waste in the process of producing furfural (Chinese Patent Application Publication No. 103113548).
  • furfuryl alcohol may not be supplied stably due to reasons such as suspension of production or production reduction due to environmental regulations at a factory for producing fururyl alcohol or furfural.
  • the binder composition for mold making of the present invention contains a furan resin, water, and a hydrolyzed starch, and a mass ratio of the furan resin to the hydrolyzed starch (mass of the furan resin / the hydrolyzed starch). (Mass of starch) is 20 to 95, and the dextrose equivalent of the hydrolyzed starch is 60 or more.
  • the present invention provides a binder composition for mold making that does not require a denaturing step while using saccharides and can suppress economic and energy costs.
  • the binder composition for mold making of the present invention contains a furan resin, water, and a hydrolyzed starch, and a mass ratio of the furan resin to the hydrolyzed starch (mass of the furan resin / the hydrolyzed starch). (Mass of starch) is 20 to 95, and the dextrose equivalent of the hydrolyzed starch is 60 or more.
  • a binder composition for mold making which does not require a denaturation step while using saccharides, and can suppress economic and energy costs.
  • the binder composition for mold making of the present embodiment (hereinafter, also simply referred to as a binder composition) contains a furan resin, water, and hydrolyzed starch, and the furan resin, the hydrolyzed starch, (Mass of the furan resin / mass of the hydrolyzed starch) is 20 to 95, and the dextrose equivalent of the hydrolyzed starch is 60 or more.
  • the binder composition of the present embodiment a denaturation step is not required while using saccharides, so that economic cost and energy cost can be suppressed.
  • the reason why the binder composition of this embodiment exhibits such an effect is not clear, but is considered as follows.
  • Starch tends to have poor solubility in furan resin, but using a hydrolyzed starch having a specific dextrose equivalent (DE equivalent), the mass ratio of the furan resin to the hydrolyzed starch (mass of the furan resin / It has been found that a certain degree of solubility in both water and furan resin can be obtained by setting the mass of the hydrolyzed starch to a specific range.
  • DE equivalent dextrose equivalent
  • the binder composition of the present embodiment it is considered that a denaturation step is not required while using saccharides, so that economic cost and energy cost can be suppressed. Further, it is considered that the binder composition can form a uniform adhesive layer without phase separation even in the kneading step with the curing agent composition and the refractory particles, and thus can maintain the mold strength. .
  • the furan resin is furfuryl alcohol, a condensate of furfuryl alcohol, a condensate of furfuryl alcohol and aldehydes, a condensate of furfuryl alcohol and urea and aldehydes (urea-modified furan resin), urea, ethylene urea and aldehyde Consisting of a condensate of urea and ethylene urea, a condensate of melamine and aldehyde, and a condensate of urea and aldehyde, and 2 selected from these groups
  • One composed of a mixture of two or more species can be exemplified.
  • those comprising two or more cocondensates selected from these groups can also be used.
  • furfuryl alcohol, a condensate of furfuryl alcohol and one or more selected from condensates of furfuryl alcohol, urea and aldehydes, and co-condensation thereof from the viewpoint of improving the curing speed of the mold and improving the mold strength It is preferable to use an object.
  • the monomer composition used for the synthesis of the furan resin contains furfuryl alcohol, and one or more monomers selected from, for example, aldehydes, urea, phenols, and melamine are selected according to the desired condensate. Is available.
  • aldehydes examples include formaldehyde, acetaldehyde, glyoxal, furfural, terephthalaldehyde, and hydroxymethylfurfural, and one or more of these can be used as appropriate. From the viewpoint of improving the mold strength, it is preferable to use formaldehyde, and from the viewpoint of reducing the amount of formaldehyde generated during molding, it is preferable to use furfural, terephthalaldehyde, or hydroxymethylfurfural.
  • phenols examples include phenol, cresol, resorcin, bisphenol A, bisphenol C, bisphenol E, bisphenol F and the like, and one or more of these can be used.
  • the reaction temperature at the time of synthesizing the furan resin varies depending on the raw materials used, and the viscosity of the obtained binder composition, the residual amount of aldehyde, the production time, the runaway reaction of the furan resin, and the prevention of evaporation of the raw materials From the viewpoint, the temperature is preferably from 50 to 150 ° C, more preferably from 70 to 130 ° C, and still more preferably from 80 to 130 ° C. From the same viewpoint, the reaction time for synthesizing the furan resin is preferably 0.5 to 12 hours, more preferably 1 to 10 hours, and still more preferably 3 to 8 hours.
  • furan resin When the furan resin is produced, furan resin, furfuryl alcohol as a raw material, water contained in the raw material, water generated during the reaction, and the like are included, but may not be removed from the viewpoint of economy.
  • the furan resin composition contains components other than the furan resin, furfuryl alcohol and the furan resin, such as water.
  • the content of the furan resin in the binder composition is preferably 50% by mass or more, more preferably 60% by mass or more, and even more preferably 65% by mass or more, from the viewpoint of improving the mold strength.
  • the content of the furan resin in the binder composition is preferably 98% by mass or less, and more preferably 95% by mass or less, from the viewpoint of viscosity reduction.
  • the content of the furan resin in the binder composition of the present embodiment is preferably from 50 to 98% by mass, more preferably from 60 to 95% by mass, and more preferably from 65 to 95% by mass from the viewpoint of improving the mold strength and decreasing the viscosity. 95 mass% is more preferred.
  • the content of water in the binder composition is preferably 0.5% by mass or more, more preferably 1% by mass or more, and still more preferably 3% by mass or more.
  • the water content of the binder composition is preferably 30% by mass or less, and more preferably 25% by mass or less.
  • the water content of the binder composition is preferably from 0.5 to 30% by mass, from the viewpoint of adjusting the viscosity of the binder composition to an easily handleable viscosity and maintaining the curing reaction rate. It is more preferably 25% by mass, and still more preferably 3 to 25% by mass.
  • the condensate When synthesizing various condensates such as a condensate of furfuryl alcohol and aldehydes, the condensate is usually obtained in the form of a mixture with water because aqueous materials are used or condensed water is generated. Can be In using such a condensate in the binder composition, water may be removed by topping or the like, if necessary, but it is necessary to remove it during production as long as the curing reaction rate can be maintained. There is no.
  • the hydrolyzed starch is obtained by hydrolyzing starch with an acid or an enzyme.
  • the dextrose equivalent of the hydrolyzed starch is 60 or more, preferably 70 or more, from the viewpoint of compatibility between the hydrolyzed starch and the furan resin.
  • the dextrose equivalent of the hydrolyzed starch is preferably 99 or less, more preferably 80 or less from the viewpoint of economy.
  • dextrose equivalent is also referred to as dextrose equivalent (Dextrose Equivalent value), which is a measurement of reducing sugars as glucose and indicates the ratio of the reducing sugars to the total solid content. It is used as an index. In the present specification, dextrose equivalent is measured by the method described in Examples.
  • hydrolyzed starch for example, Fuji Syrup (Kato Kagaku) or the like is obtained as a commercial product.
  • the mass ratio of the furan resin to the hydrolyzed starch (mass of the furan resin / mass of the hydrolyzed starch) is from 20 to 95 from the viewpoint of compatibility between the hydrolyzed starch and the furan resin, and 90 is preferred.
  • the mass ratio of water to the hydrolyzed starch (mass of water / mass of the hydrolyzed starch) is from 1 to 30 from the viewpoint of the compatibility of the hydrolyzed starch and water with respect to the water, 2 to 20 are preferred.
  • the content of the hydrolyzed starch is preferably 1% by mass or more, more preferably 2% by mass or more from the viewpoint of economy.
  • the content of the hydrolyzed starch is preferably 20% by mass or less, more preferably 10% by mass or less, from the viewpoint of compatibility between the hydrolyzed starch and the furan resin and the viewpoint of mold strength.
  • the content of the hydrolyzed starch is preferably from 1 to 20% by mass, more preferably from 2 to 10% by mass from the viewpoints of economy, compatibility of the hydrolyzed starch and the furan resin, and mold strength. preferable.
  • the binder composition of the present embodiment may contain a curing accelerator from the viewpoint of preventing mold cracking and improving the final mold strength.
  • a curing accelerator from the viewpoint of improving the final mold strength, a compound represented by the following general formula (1) (hereinafter, referred to as curing accelerator (1)), a phenol derivative, an aromatic dialdehyde, and tannin
  • curing accelerator (1) a compound represented by the following general formula (1)
  • phenol derivative a phenol derivative
  • aromatic dialdehyde aromatic dialdehyde
  • tannin One or more selected from the group consisting of
  • X 1 and X 2 each represent a hydrogen atom, CH 3 or C 2 H 5 .
  • the content of the curing accelerator in the binder composition is preferably 0.5% by mass or more, more preferably 1.8% by mass or more. , 2.5% by mass or more, even more preferably 3.0% by mass or more.
  • the content of the curing accelerator in the binder composition is preferably 63% by mass or less from the viewpoint of solubility of the curing accelerator in the furan resin and improving the final strength of the mold, and is preferably 50% by mass or less. %, More preferably 40% by weight or less.
  • Examples of the curing accelerator (1) include 2,5-bishydroxymethylfuran, 2,5-bismethoxymethylfuran, 2,5-bisethoxymethylfuran, 2-hydroxymethyl-5-methoxymethylfuran, and 2-hydroxymethylfuran.
  • Methyl-5-ethoxymethylfuran and 2-methoxymethyl-5-ethoxymethylfuran are exemplified. Among them, it is preferable to use 2,5-bishydroxymethylfuran from the viewpoint of improving the final mold strength.
  • phenol derivative examples include resorcin, cresol, hydroquinone, phloroglucinol, and methylenebisphenol.
  • resorcinol is preferable from the viewpoint of the deep curing property of the mold and the viewpoint of improving the final mold strength.
  • the content of the phenol derivative in the binder composition is preferably 1 to 25% by mass from the viewpoint of the solubility of the phenol derivative in the furan resin and from the viewpoint of improving the final mold strength.
  • the content is more preferably 2 to 15% by mass, and still more preferably 3 to 10% by mass.
  • the content of resorcin in the binder composition is from 1 to 10% by mass from the viewpoint of solubility of resorcin in furan resin and improving final mold strength. Is preferably 2 to 7% by mass, and more preferably 3 to 6% by mass.
  • Aromatic dialdehydes include terephthalaldehyde, phthalaldehyde, isophthalaldehyde, and the like, and derivatives thereof. These derivatives mean compounds having a substituent such as an alkyl group on the aromatic ring of an aromatic compound having two formyl groups as the basic skeleton. From the viewpoint of preventing the mold from cracking, terephthalaldehyde and terephthalaldehyde derivatives are preferable, and terephthalaldehyde is more preferable.
  • the content of the aromatic dialdehyde in the binder composition is preferably 0.1 to 0.1 from the viewpoint of sufficiently dissolving the aromatic dialdehyde in the furan resin and suppressing the odor of the aromatic dialdehyde itself.
  • the content is 15% by mass, more preferably 0.5 to 10% by mass, and still more preferably 1 to 5% by mass.
  • the tannins include condensed tannins and hydrolyzed tannins.
  • condensed tannins and hydrolyzable tannins include tannins having a pyrogallol skeleton and a resorcinol skeleton.
  • bark extracts containing these tannins or extracts from natural products such as plant-derived leaves, fruits, seeds, and galls parasitic on plants may be added.
  • the binder composition may further contain an additive such as a silane coupling agent.
  • a silane coupling agent include N- ⁇ - (aminoethyl) - ⁇ -aminopropylmethyldimethoxysilane, N- ⁇ - (aminoethyl) - ⁇ -aminopropyltrimethoxysilane, N- ⁇ - (aminoethyl)- aminosilanes such as ⁇ -aminopropyltriethoxysilane and 3-aminopropyltrimethoxysilane, 3-glycidoxypropyltrimethoxysilane, 3-glycidoxypropyltriethoxysilane, and 3-glycidoxypropylmethyldiethoxysilane And epoxyglycols such as 3-glycidoxypropyltriethoxysi
  • aminosilane epoxysilane and ureidosilane. More preferred are aminosilane and epoxysilane, and even more preferred are aminosilane.
  • aminosilanes N- ⁇ - (aminoethyl) - ⁇ -aminopropylmethyldimethoxysilane is preferred.
  • the content of the silane coupling agent in the binder composition is preferably 0.01% by mass or more, and more preferably 0.05% by mass or more. From the same viewpoint, the content of the silane coupling agent in the binder composition is preferably equal to or less than 1.0% by mass, and more preferably equal to or less than 0.5% by mass.
  • the binder composition may contain one or more alcohols selected from the group consisting of methanol, ethanol, ethylene glycol, propylene glycol, and glycerin from the viewpoint of reducing economic costs.
  • the content of the alcohol is preferably 1% by mass or more, more preferably 2% by mass or more.
  • the content of the alcohol is preferably 10% by mass or less from the viewpoint of suppressing a decrease in strength of the mold.
  • the content of the alcohol is preferably 1 to 10% by mass, more preferably 2 to 10% by mass, from the viewpoint of preventing freezing in a low-temperature environment and suppressing the reduction in strength of the mold.
  • the binder composition may contain urea from the viewpoint of improving mold strength.
  • the urea is urea that has not been condensed with formaldehyde, furfuryl alcohol, or the like, and may be either remaining as an unreacted component or separately added.
  • the content of the urea in the binder composition is preferably 0.5% by mass or more, more preferably 0.8% by mass or more, from the viewpoint of improving the mold strength and reducing the formaldehyde concentration. 0 mass% or more is more preferable.
  • the content of the urea in the binder composition is preferably 10% by mass or less, more preferably 6.0% by mass or less, from the viewpoint of improving the curing speed and the storage stability of the binder composition. It is more preferably at most 4.5% by mass.
  • the urea in the binder composition can be measured by the following LC / MS analysis operation.
  • the binder composition may contain a phenol resin from the viewpoint of improving the flexibility of the mold and improving the final strength of the mold.
  • phenol resin include those having a weight average molecular weight of 1,000 to 5,000.
  • the phenolic resin has a weight average molecular weight of preferably 1000 or more, more preferably 1400 or more, from the viewpoint of improving the mold flexibility and the final strength of the mold. From the same viewpoint, it is preferably 5000 or less, more preferably 2500 or less. Therefore, it is preferably from 1,000 to 5,000, more preferably from 1,400 to 2,500.
  • the dispersity (the ratio of weight average molecular weight / number average molecular weight) of the phenol resin is preferably 1.2 or more, and more preferably 1.8 or more, from the viewpoint of improving the flexibility of the mold and improving the final strength of the mold. Is more preferred.
  • the weight average molecular weight of the phenolic resin is preferably 5.0 or less from the viewpoint of improving the storage stability of the binder composition, improving the flexibility of the mold and improving the final strength of the mold, 3.5 or less is more preferable. Therefore, 1.2 to 5.0 is preferable, and 1.8 to 3.5 is more preferable.
  • phenol resin conventionally known ones can be used.
  • a resol type phenol resin, a novolak type phenol resin, and a phenol resin having a structure as described in Japanese Patent Application No. 2009-292862 are used.
  • Those composed of one selected from the group or those composed of a mixture of two or more selected from these groups can be used.
  • phenols used to obtain a resol type phenol resin include phenol, cresol, xylenol, and the like, but among these, a viewpoint of improving the flexibility of the mold and a viewpoint of improving the final strength of the mold.
  • phenol is preferred.
  • aldehydes used for obtaining the resole type phenol resin include formaldehyde, glyoxal, paraformaldehyde, furfural, 5-hydroxymethylfurfural and the like, but from the viewpoint of improving the flexibility of the mold and the final strength of the mold.
  • Paraformaldehyde is preferred from the viewpoint of improving the odor.
  • the basic catalyst used for obtaining the resole type phenol resin include potassium hydroxide, sodium hydroxide and the like.
  • the phenols and aldehydes used to obtain a novolak phenol resin include the same phenols and aldehydes as the resol phenol resin.
  • raw materials, water contained in the raw materials, and water generated during the reaction are contained in addition to the phenolic resin, but may not be removed from the viewpoint of economy.
  • phenolic resins it is preferable to use a resol-type phenolic resin from the viewpoint of solubility, improving the flexibility of the mold, and improving the final strength of the mold.
  • the content of the phenol resin in the binder composition is 2% by mass or more and 35% by mass or less from the viewpoint of solubility, improving the flexibility of the mold, and improving the final strength of the mold. .
  • the content of the phenol resin in the binder composition is more preferably 8% by mass or more from the viewpoint of improving the mold flexibility and the final strength of the mold.
  • the content of the phenol resin in the binder composition is more preferably 20% by mass or less from the viewpoint of solubility, improving the flexibility of the mold, and improving the final strength of the mold. Therefore, 8 to 20% by mass is more preferable.
  • the total content of the furan resin and the phenol resin in the binder composition is preferably 50% by mass or more from the viewpoint of improving the final strength of the mold.
  • the total content of the furan resin and the phenol resin in the binder composition is preferably 95% by mass or less from the viewpoint of improving the final strength of the mold. Therefore, 50 to 95% by mass is preferable.
  • the binder composition is suitably used for molding a self-hardening mold.
  • the self-hardening mold is a mold in which when a binder composition and a curing agent composition are mixed with sand, a polymerization reaction proceeds with the passage of time and the mold is cured.
  • the temperature of the sand used at that time is in the range of ⁇ 20 ° C. to 50 ° C., preferably 0 ° C. to 40 ° C.
  • a proper amount of a curing agent is selected and added to the sand, whereby the mold can be appropriately cured.
  • the binder composition can be mixed with the refractory particles and the hardener composition to form a mold composition.
  • the composition for a mold of the present embodiment contains the binder composition, the refractory particles, and the curing agent composition.
  • Refractory particles As the refractory particles, silica sand, chromite sand, zircon sand, olivine sand, alumina sand, mullite sand, conventionally known ones such as synthetic mullite sand can be used, and those obtained by collecting used refractory particles and Those that have been reproduced can also be used.
  • the curing agent composition can be used without any particular limitation as long as it contains a curing agent for curing the binder composition.
  • the curing agent include acid-based curing agents, such as sulfonic acid compounds such as xylene sulfonic acid (particularly, m-xylene sulfonic acid), toluene sulfonic acid (particularly, p-toluene sulfonic acid), methane sulfonic acid, and the like.
  • One or more conventionally known compounds such as an acid, a phosphoric acid compound such as an acidic phosphoric ester, an acidic aqueous solution containing sulfuric acid and the like can be used. These compounds are preferably aqueous solutions from the viewpoint of handleability.
  • the curing agent may contain one or more solvents selected from the group consisting of alcohols, ether alcohols and esters, and carboxylic acids.
  • the content of the curing agent in the curing agent composition is preferably from 5 to 50% by mass, and more preferably from 10 to 40% by mass, from the viewpoint of ultimately improving the strength of the mold.
  • the composition for a mold contains 0.5 to 3.0 parts by mass of the binder composition and 0.07 to 2.0 parts by mass of the curing agent composition based on 100 parts by mass of the refractory particles. Is preferred.
  • the content of the curing agent composition in the composition for a mold is preferably 0.1 part by mass or more, more preferably 0 part by mass, based on 1.0 part by mass of the binder composition from the viewpoint of improving the mold strength. .14 parts by mass or more, more preferably 0.2 parts by mass or more, preferably 0.8 parts by mass or less, more preferably 0.6 parts by mass or less, still more preferably 0.4 parts by mass or less.
  • the content of the curing agent composition in the composition for a mold is preferably 0.1 to 0.8 parts by mass with respect to 1.0 part by mass of the binder composition from the viewpoint of improving mold strength. Parts, more preferably 0.14 to 0.6 parts by mass, even more preferably 0.2 to 0.4 parts by mass.
  • a mold can be produced by curing the mold composition.
  • the mold can be manufactured by using the conventional mold manufacturing process as it is.
  • As a preferred method for producing a mold mixing the refractory particles, the binder composition for mold molding, and a curing agent composition for curing the binder composition for mold molding to obtain a composition for mold.
  • a method for producing a mold having a curing step of packing the mold composition into a mold and curing the mold composition are examples of the mold composition.
  • the mixing step includes a first mixing step of mixing the refractory particles and a curing agent composition for mold molding containing the curing agent composition, and a binder composition for mold molding added to the mixture obtained after the first mixing step. It is preferable to have a second mixing step of mixing the substances.
  • an acid-curable resin In the mixing step, an acid-curable resin, a curing accelerator, water, additives such as a silane coupling agent, an acidic substance, and a solvent may be added to such an extent that the effects of the present embodiment are not impaired.
  • a known general method can be used, for example, a method of adding and mixing the respective raw materials by a batch mixer, or a method of supplying the respective raw materials to a continuous mixer and kneading. Method.
  • the composition of the furan resin composition was 71.7% by mass of a urea-modified furan resin, 19.5% by mass of furfuryl alcohol, and 8.8% by mass of water.
  • [Dextrose equivalent] Precisely weigh 2.5 g of sample and dissolve in water to make 200 mL. 10 mL of this solution was accurately measured, 10 mL of a 0.04 mol / L iodine solution and 15 mL of a 0.04 mol / L sodium hydroxide solution were added, and the mixture was left in a dark place for 20 minutes. Next, 5 mL of 2 mol / L hydrochloric acid was added and mixed, and then titrated with a 0.04 mol / L sodium thiosulfate solution.
  • the strength (MPa) was measured.
  • the binder composition used in preparing the composition for a mold was used after shaking the one that had been stored at room temperature for one week. Table 1 shows the results. In Examples 1 to 9, the pressure was 4.7 MPa or more.
  • Comparative Examples 1 to 4 had a compression strength of 4.4 MPa or less and low compressive strength. This is considered to be due to the fact that in the comparative example, the hydrolyzed starch was phase-separated in the binder composition, and the hydrolyzed starch was agglomerated in the mold composition.

Abstract

The binder composition for forming a mold according to the present invention contains a furan resin, water, and hydrolyzed starch, wherein the mass ratio of the furan resin and the hydrolyzed starch (mass of furan resin/ mass of hydrolyzed starch) is 20-95, and the hydrolyzed starch has a dextrose equivalent of 60 or more. The present invention can provide a binder composition that is for forming a mold and that does not require a modification step even while using a sugar, resulting in reduction of economic cost and energy cost.

Description

鋳型造型用粘結剤組成物Binder composition for mold making
　本発明は、鋳型造型用粘結剤組成物に関する。 The present invention relates to a binder composition for mold making.
　一般に、酸硬化性鋳型は、珪砂等の耐火性粒子に、酸硬化性樹脂を含有する鋳型造型用粘結剤組成物と、スルホン酸、硫酸、リン酸等を含有する硬化剤組成物とを添加し、これらを混練した後、得られた混練砂を木型等の原型に充填し、酸硬化性樹脂を硬化させて製造される。酸硬化性樹脂には、フラン樹脂やフェノール樹脂等が用いられており、フラン樹脂には、フルフリルアルコール、フルフリルアルコール・尿素・ホルムアルデヒド樹脂、フルフリルアルコール・ホルムアルデヒド樹脂、フルフリルアルコール・フェノール・ホルムアルデヒド樹脂、その他公知の変性フラン樹脂等が用いられている。このような鋳型の製造方法は自由度の高い造型作業が可能であり、また鋳型の熱的性質に優れることから高品質の鋳物が製造できるため、機械部品や建設機械部品、あるいは自動車用部品等の鋳物を鋳造する際に広く使用されている。 Generally, an acid-curable mold is a refractory particle such as silica sand, a mold-forming binder composition containing an acid-curable resin, and a curing agent composition containing sulfonic acid, sulfuric acid, phosphoric acid, and the like. After the addition and kneading, the obtained kneading sand is filled in a prototype such as a wooden mold, and the acid-curable resin is cured to produce the mixture. Furan resin and phenol resin are used as the acid-curable resin. Furfuryl alcohol, furfuryl alcohol / urea / formaldehyde resin, furfuryl alcohol / formaldehyde resin, furfuryl alcohol / phenol / Formaldehyde resins and other known modified furan resins are used. Such a method of manufacturing a mold allows for a high degree of freedom in molding work, and because of the excellent thermal properties of the mold, high-quality castings can be manufactured. Therefore, machine parts, construction machine parts, automobile parts, etc. It is widely used when casting castings.
　前記したようにフルフリルアルコールはフラン樹脂など酸硬化性樹脂の構成成分として広く用いられている。ところが、フルフリルアルコールは、トウモロコシの芯など農業副産物からなる原料を加水分解、脱水してフルフラールを得る工程、そしてフルフラールを水添する工程を経て製造され、製造コストは比較的高いものになる。また、フルフラールの製造工程で大量の残渣が廃棄物として生じる（中国特許出願公開第１０３１１３５４８号明細書）。また、近年では、フルリルアルコールやフルフラールの製造工場が環境規制によって操業停止や減産体制をとるなどの理由で、フルフリルアルコールが安定に供給されない場合がある。以上の背景から、安価で環境への負荷が低く、供給安定性の高いフルフリルアルコール代替原料が求められている。 As described above, furfuryl alcohol is widely used as a component of acid-curable resins such as furan resins. However, furfuryl alcohol is produced through a process of hydrolyzing and dehydrating a raw material composed of agricultural by-products such as corn core to obtain furfural, and a process of hydrogenating furfural, and the production cost is relatively high. In addition, a large amount of residue is generated as waste in the process of producing furfural (Chinese Patent Application Publication No. 103113548). Further, in recent years, furfuryl alcohol may not be supplied stably due to reasons such as suspension of production or production reduction due to environmental regulations at a factory for producing fururyl alcohol or furfural. In view of the above background, there is a need for a furfuryl alcohol alternative material that is inexpensive, has low environmental impact, and has a high supply stability.
　安価で環境への負荷が低く、供給安定性の高い剤として糖類が挙げられ、これまでにフルフリルアルコールの一部を糖類で代替したフラン樹脂の製造方法も報告されている（中国特許出願公開第１０２８６１８６７号明細書）。 Sugars are listed as agents that are inexpensive, have a low impact on the environment, and have a high supply stability. So far, a method for producing a furan resin in which a portion of furfuryl alcohol has been replaced with saccharides has been reported (Chinese patent application published) No. 102861867).
　本発明の鋳型造型用粘結剤組成物は、フラン樹脂と、水と、加水分解澱粉とを含有し、前記フラン樹脂と前記加水分解澱粉との質量比（前記フラン樹脂の質量／前記加水分解澱粉の質量）が２０～９５であり、前記加水分解澱粉のデキストロース当量が６０以上である。 The binder composition for mold making of the present invention contains a furan resin, water, and a hydrolyzed starch, and a mass ratio of the furan resin to the hydrolyzed starch (mass of the furan resin / the hydrolyzed starch). (Mass of starch) is 20 to 95, and the dextrose equivalent of the hydrolyzed starch is 60 or more.
発明の詳細な説明Detailed description of the invention
　糖類はフラン樹脂への溶解性が悪いため、これまで、フラン樹脂と反応させるなど、変性させてフラン樹脂への溶解性を高める必要があった。しかし、当該変性には煩雑な工程が必要であり、経済的コスト及びエネルギーコストを要していた。 Since saccharides have poor solubility in furan resins, it has been necessary to increase the solubility in furan resins by modifying them, such as by reacting with furan resins. However, the denaturation requires a complicated process, and requires an economic cost and an energy cost.
　本発明は、糖類を用いながら変性工程が不要で経済的コスト及びエネルギーコストを抑制できる鋳型造型用粘結剤組成物を提供する。 The present invention provides a binder composition for mold making that does not require a denaturing step while using saccharides and can suppress economic and energy costs.
　本発明の鋳型造型用粘結剤組成物は、フラン樹脂と、水と、加水分解澱粉とを含有し、前記フラン樹脂と前記加水分解澱粉との質量比（前記フラン樹脂の質量／前記加水分解澱粉の質量）が２０～９５であり、前記加水分解澱粉のデキストロース当量が６０以上である。 The binder composition for mold making of the present invention contains a furan resin, water, and a hydrolyzed starch, and a mass ratio of the furan resin to the hydrolyzed starch (mass of the furan resin / the hydrolyzed starch). (Mass of starch) is 20 to 95, and the dextrose equivalent of the hydrolyzed starch is 60 or more.
　本発明によれば、糖類を用いながら変性工程が不要で経済的コスト及びエネルギーコストを抑制できる鋳型造型用粘結剤組成物を提供することができる。 According to the present invention, it is possible to provide a binder composition for mold making, which does not require a denaturation step while using saccharides, and can suppress economic and energy costs.
　以下、本発明の一実施形態について説明する。 Hereinafter, an embodiment of the present invention will be described.
＜鋳型造型用粘結剤組成物＞
　本実施形態の鋳型造型用粘結剤組成物（以下、単に粘結剤組成物ともいう）は、フラン樹脂と、水と、加水分解澱粉とを含有し、前記フラン樹脂と前記加水分解澱粉との質量比（前記フラン樹脂の質量／前記加水分解澱粉の質量）が２０～９５であり、前記加水分解澱粉のデキストロース当量が６０以上である。 <Binder composition for mold making>
The binder composition for mold making of the present embodiment (hereinafter, also simply referred to as a binder composition) contains a furan resin, water, and hydrolyzed starch, and the furan resin, the hydrolyzed starch, (Mass of the furan resin / mass of the hydrolyzed starch) is 20 to 95, and the dextrose equivalent of the hydrolyzed starch is 60 or more.
　本実施形態の粘結剤組成物によれば、糖類を用いながら変性工程が不要で経済的コスト及びエネルギーコストを抑制できる。本実施形態の粘結剤組成物がこのような効果を奏する理由は定かではないが、以下のように考えられる。 According to the binder composition of the present embodiment, a denaturation step is not required while using saccharides, so that economic cost and energy cost can be suppressed. The reason why the binder composition of this embodiment exhibits such an effect is not clear, but is considered as follows.
　澱粉はフラン樹脂に対する溶解性が悪い傾向があるが、特定のデキストロース等量（ＤＥ等量）をもつ加水分解澱粉を用いて、フラン樹脂と加水分解澱粉との質量比（前記フラン樹脂の質量／前記加水分解澱粉の質量）を特定の範囲にすることによって水及びフラン樹脂両方に対する一定以上の溶解性を得ることができることを見出した。そのため、フラン樹脂と加水分解澱粉との質量比を特定の範囲にすれば、フラン樹脂への溶解性を高めるためにあえて糖類を変性させる必要がなく、粘結剤組成物を調整後、長期間放置しても糖類がフラン樹脂成分などと相分離することなく均一な状態を保持できる。したがって、本実施形態の粘結剤組成物によれば、糖類を用いながら変性工程が不要で経済的コスト及びエネルギーコストを抑制できると考えられる。さらに、前記粘結剤組成物は、硬化剤組成物や耐火性粒子との混練工程においても相分離することなく、均一な接着層を形成できるため、鋳型強度を維持することができると考えられる。 Starch tends to have poor solubility in furan resin, but using a hydrolyzed starch having a specific dextrose equivalent (DE equivalent), the mass ratio of the furan resin to the hydrolyzed starch (mass of the furan resin / It has been found that a certain degree of solubility in both water and furan resin can be obtained by setting the mass of the hydrolyzed starch to a specific range. Therefore, if the mass ratio of the furan resin and the hydrolyzed starch is in a specific range, it is not necessary to denature the saccharide in order to increase the solubility in the furan resin, and after adjusting the binder composition for a long time, Even if left as it is, the saccharide can maintain a uniform state without phase separation from the furan resin component and the like. Therefore, according to the binder composition of the present embodiment, it is considered that a denaturation step is not required while using saccharides, so that economic cost and energy cost can be suppressed. Further, it is considered that the binder composition can form a uniform adhesive layer without phase separation even in the kneading step with the curing agent composition and the refractory particles, and thus can maintain the mold strength. .
〔フラン樹脂〕
　前記フラン樹脂は、フルフリルアルコール、フルフリルアルコールの縮合物、フルフリルアルコールとアルデヒド類の縮合物、フルフリルアルコールと尿素とアルデヒド類の縮合物（尿素変性フラン樹脂）、尿素とエチレン尿素とアルデヒド類の縮合物（尿素・エチレン尿素共縮合樹脂）、メラミンとアルデヒド類の縮合物、及び尿素とアルデヒド類の縮合物よりなる群から選ばれる１種からなるものや、これらの群から選ばれる２種以上の混合物からなるものが例示できる。また、これらの群から選ばれる２種以上の共縮合物からなるものも使用できる。このうち、鋳型の硬化速度向上と鋳型強度向上の観点から、フルフリルアルコール、フルフリルアルコールの縮合物及びフルフリルアルコールと尿素とアルデヒド類の縮合物から選ばれる１種以上、並びにこれらの共縮合物を使用するのが好ましい。 (Furan resin)
The furan resin is furfuryl alcohol, a condensate of furfuryl alcohol, a condensate of furfuryl alcohol and aldehydes, a condensate of furfuryl alcohol and urea and aldehydes (urea-modified furan resin), urea, ethylene urea and aldehyde Consisting of a condensate of urea and ethylene urea, a condensate of melamine and aldehyde, and a condensate of urea and aldehyde, and 2 selected from these groups One composed of a mixture of two or more species can be exemplified. Further, those comprising two or more cocondensates selected from these groups can also be used. Among these, furfuryl alcohol, a condensate of furfuryl alcohol and one or more selected from condensates of furfuryl alcohol, urea and aldehydes, and co-condensation thereof, from the viewpoint of improving the curing speed of the mold and improving the mold strength It is preferable to use an object.
　前記フラン樹脂の合成に用いられるモノマー組成物は、フルフリルアルコールを含有し、目的の縮合物に応じて、例えば、アルデヒド類、尿素、フェノール類、及びメラミンから選ばれる１種以上のモノマーが選択され、使用できる。 The monomer composition used for the synthesis of the furan resin contains furfuryl alcohol, and one or more monomers selected from, for example, aldehydes, urea, phenols, and melamine are selected according to the desired condensate. Is available.
　前記アルデヒド類としては、ホルムアルデヒド、アセトアルデヒド、グリオキザール、フルフラール、テレフタルアルデヒド、ヒドロキシメチルフルフラール等が挙げられ、これらのうち１種以上を適宜使用できる。鋳型強度向上の観点からは、ホルムアルデヒドを用いるのが好ましく、造型時のホルムアルデヒド発生量低減の観点からは、フルフラールやテレフタルアルデヒド、ヒドロキシメチルフルフラールを用いるのが好ましい。 ア ル デ ヒ ド Examples of the aldehydes include formaldehyde, acetaldehyde, glyoxal, furfural, terephthalaldehyde, and hydroxymethylfurfural, and one or more of these can be used as appropriate. From the viewpoint of improving the mold strength, it is preferable to use formaldehyde, and from the viewpoint of reducing the amount of formaldehyde generated during molding, it is preferable to use furfural, terephthalaldehyde, or hydroxymethylfurfural.
　前記フェノール類としては、フェノール、クレゾール、レゾルシン、ビスフェノールＡ、ビスフェノールＣ、ビスフェノールＥ、ビスフェノールＦなどが挙げられ、これらのうち１種以上を使用できる。 Examples of the phenols include phenol, cresol, resorcin, bisphenol A, bisphenol C, bisphenol E, bisphenol F and the like, and one or more of these can be used.
　フルフリルアルコールとアルデヒド類の縮合物を製造する場合には、フルフリルアルコール１モルに対して、アルデヒド類を０．０１～１モル使用することが好ましい。また、フルフリルアルコールとアルデヒド類と尿素の縮合物を製造する場合には、フルフリルアルコール１モルに対して、アルデヒド類を０．０５～３モル、尿素を０．０３～１．５モル使用することが好ましい。 When producing a condensate of furfuryl alcohol and aldehydes, it is preferable to use 0.01 to 1 mol of aldehydes per 1 mol of furfuryl alcohol. When producing a condensate of furfuryl alcohol, aldehydes and urea, 0.05 to 3 mol of aldehyde and 0.03 to 1.5 mol of urea are used per 1 mol of furfuryl alcohol. Is preferred.
　フラン樹脂を合成する際の反応温度は、使用する原料により異なり、得られる粘結剤組成物の粘度、アルデヒドの残留量、製造時間短縮、フラン樹脂の暴走反応の防止や、原料の蒸発防止の観点から、５０～１５０℃が好ましく、７０～１３０℃がより好ましく、８０～１３０℃が更に好ましい。同様の観点から、フラン樹脂を合成する際の反応時間は、０．５～１２時間が好ましく、１～１０時間がより好ましく、３～８時間が更に好ましい。 The reaction temperature at the time of synthesizing the furan resin varies depending on the raw materials used, and the viscosity of the obtained binder composition, the residual amount of aldehyde, the production time, the runaway reaction of the furan resin, and the prevention of evaporation of the raw materials From the viewpoint, the temperature is preferably from 50 to 150 ° C, more preferably from 70 to 130 ° C, and still more preferably from 80 to 130 ° C. From the same viewpoint, the reaction time for synthesizing the furan resin is preferably 0.5 to 12 hours, more preferably 1 to 10 hours, and still more preferably 3 to 8 hours.
　フラン樹脂を製造する際、フラン樹脂、原料のフルフリルアルコール、原料に含まれる水、反応中に生成する水等が含まれるが、経済性の観点から除去しなくてもよい。フラン樹脂組成物は、フラン樹脂、フルフリルアルコール及びフラン樹脂以外の成分、例えば水等を含有する。 When the furan resin is produced, furan resin, furfuryl alcohol as a raw material, water contained in the raw material, water generated during the reaction, and the like are included, but may not be removed from the viewpoint of economy. The furan resin composition contains components other than the furan resin, furfuryl alcohol and the furan resin, such as water.
　前記粘結剤組成物におけるフラン樹脂の含有量は、鋳型強度向上の観点から、５０質量％以上が好ましく、６０質量％以上がより好ましく、６５質量％以上が更に好ましい。前記粘結剤組成物におけるフラン樹脂の含有量は、粘度低減の観点から、９８質量％以下がより好ましく、９５質量％以下が更に好ましい。また、本実施形態の粘結剤組成物におけるフラン樹脂の含有量は、鋳型強度向上の観点及び粘度低減の観点から、５０～９８質量％が好ましく、６０～９５質量％がより好ましく、６５～９５質量％が更に好ましい。 フ ラ ン The content of the furan resin in the binder composition is preferably 50% by mass or more, more preferably 60% by mass or more, and even more preferably 65% by mass or more, from the viewpoint of improving the mold strength. The content of the furan resin in the binder composition is preferably 98% by mass or less, and more preferably 95% by mass or less, from the viewpoint of viscosity reduction. Further, the content of the furan resin in the binder composition of the present embodiment is preferably from 50 to 98% by mass, more preferably from 60 to 95% by mass, and more preferably from 65 to 95% by mass from the viewpoint of improving the mold strength and decreasing the viscosity. 95 mass% is more preferred.
〔水〕
　前記粘結剤組成物の水の含有量は０．５質量％以上が好ましく、１質量％以上がより好ましく、３質量％以上が更に好ましい。ただし、硬化反応速度を維持する観点から、粘結剤組成物の水の含有量は３０質量％以下が好ましく、２５質量％以下がより好ましい。また、粘結剤組成物の水の含有量は、粘結剤組成物を取扱いやすい粘度に調整する観点、及び硬化反応速度を維持する観点から、０．５～３０質量％が好ましく、１～２５質量％がより好ましく、３～２５質量％が更に好ましい。 〔water〕
The content of water in the binder composition is preferably 0.5% by mass or more, more preferably 1% by mass or more, and still more preferably 3% by mass or more. However, from the viewpoint of maintaining the curing reaction rate, the water content of the binder composition is preferably 30% by mass or less, and more preferably 25% by mass or less. The water content of the binder composition is preferably from 0.5 to 30% by mass, from the viewpoint of adjusting the viscosity of the binder composition to an easily handleable viscosity and maintaining the curing reaction rate. It is more preferably 25% by mass, and still more preferably 3 to 25% by mass.
　フルフリルアルコールとアルデヒド類の縮合物などの各種縮合物を合成する場合、水溶液状の原料を使用したり縮合水が生成したりするため、縮合物は、通常、水との混合物の形態で得られる。このような縮合物を粘結剤組成物に使用するにあたり、水は必要に応じて、トッピング等で除去しても構わないが、硬化反応速度を維持できる限り、製造の際にあえて除去する必要はない。 When synthesizing various condensates such as a condensate of furfuryl alcohol and aldehydes, the condensate is usually obtained in the form of a mixture with water because aqueous materials are used or condensed water is generated. Can be In using such a condensate in the binder composition, water may be removed by topping or the like, if necessary, but it is necessary to remove it during production as long as the curing reaction rate can be maintained. There is no.
〔加水分解澱粉〕
　前記加水分解澱粉は、酸や酵素等によって澱粉を加水分解したものである。当該加水分解澱粉のデキストロース当量は、前記加水分解澱粉と前記フラン樹脂の相溶性の観点から６０以上であり、７０以上が好ましい。当該加水分解澱粉のデキストロース当量は、経済性の観点から９９以下が好ましく、８０以下がより好ましい。ここでデキストロース等量とは、デキストロース当量値（Dextrose Equivalent値）ともいい、 還元糖をグルコースとして測定し、その還元糖の全固形分に対する割合を示すものであり、 デンプン分解物の分解度の一指標として用いられるものである。本明細書において、デキストロース当量は実施例に記載の方法により測定する。 (Hydrolyzed starch)
The hydrolyzed starch is obtained by hydrolyzing starch with an acid or an enzyme. The dextrose equivalent of the hydrolyzed starch is 60 or more, preferably 70 or more, from the viewpoint of compatibility between the hydrolyzed starch and the furan resin. The dextrose equivalent of the hydrolyzed starch is preferably 99 or less, more preferably 80 or less from the viewpoint of economy. Here, dextrose equivalent is also referred to as dextrose equivalent (Dextrose Equivalent value), which is a measurement of reducing sugars as glucose and indicates the ratio of the reducing sugars to the total solid content. It is used as an index. In the present specification, dextrose equivalent is measured by the method described in Examples.
　前記加水分解澱粉としては、例えば、フジシラップ（加藤化学）等が市販品として得られる。 As the hydrolyzed starch, for example, Fuji Syrup (Kato Kagaku) or the like is obtained as a commercial product.
　前記フラン樹脂と前記加水分解澱粉との質量比（前記フラン樹脂の質量／前記加水分解澱粉の質量）は、前記加水分解澱粉と前記フラン樹脂の相溶性の観点から２０～９５であり、７０～９０が好ましい。 The mass ratio of the furan resin to the hydrolyzed starch (mass of the furan resin / mass of the hydrolyzed starch) is from 20 to 95 from the viewpoint of compatibility between the hydrolyzed starch and the furan resin, and 90 is preferred.
　水と前記加水分解澱粉との質量比（水の質量／前記加水分解澱粉の質量）は、前記加水分解澱粉と水の相溶性の観点から水との相溶性の観点から１～３０であり、２～２０が好ましい。 The mass ratio of water to the hydrolyzed starch (mass of water / mass of the hydrolyzed starch) is from 1 to 30 from the viewpoint of the compatibility of the hydrolyzed starch and water with respect to the water, 2 to 20 are preferred.
　前記加水分解澱粉の含有量は、経済性の観点から、１質量％以上が好ましく、２質量％以上がより好ましい。前記加水分解澱粉の含有量は、前記加水分解澱粉と前記フラン樹脂の相溶性の観点、及び鋳型強度の観点から、２０質量％以下が好ましく、１０質量％以下がより好ましい。前記加水分解澱粉の含有量は、経済性の観点、前記加水分解澱粉と前記フラン樹脂の相溶性の観点、及び鋳型強度の観点から、１～２０質量％が好ましく、２～１０質量％がより好ましい。 か ら The content of the hydrolyzed starch is preferably 1% by mass or more, more preferably 2% by mass or more from the viewpoint of economy. The content of the hydrolyzed starch is preferably 20% by mass or less, more preferably 10% by mass or less, from the viewpoint of compatibility between the hydrolyzed starch and the furan resin and the viewpoint of mold strength. The content of the hydrolyzed starch is preferably from 1 to 20% by mass, more preferably from 2 to 10% by mass from the viewpoints of economy, compatibility of the hydrolyzed starch and the furan resin, and mold strength. preferable.
〔硬化促進剤〕
　本実施形態の粘結剤組成物中には、鋳型の割れを防ぐ観点、及び最終的な鋳型強度を向上させる観点から、硬化促進剤が含まれていてもよい。硬化促進剤としては、最終的な鋳型強度を向上させる観点から、下記一般式（１）で表される化合物（以下、硬化促進剤（１）という）、フェノール誘導体、芳香族ジアルデヒド、及びタンニン類からなる群より選ばれる１種以上が好ましい。 (Curing accelerator)
The binder composition of the present embodiment may contain a curing accelerator from the viewpoint of preventing mold cracking and improving the final mold strength. As the curing accelerator, from the viewpoint of improving the final mold strength, a compound represented by the following general formula (1) (hereinafter, referred to as curing accelerator (1)), a phenol derivative, an aromatic dialdehyde, and tannin One or more selected from the group consisting of
Figure JPOXMLDOC01-appb-C000001
  
〔式中、Ｘ１及びＸ２は、それぞれ水素原子、ＣＨ３又はＣ２Ｈ５の何れかを表す。〕
Figure JPOXMLDOC01-appb-C000001
[Wherein, X 1 and X 2 each represent a hydrogen atom, CH 3 or C 2 H 5 . ]
　前記粘結剤組成物中の硬化促進剤の含有量は、鋳型の最終強度を向上させる観点から、０．５質量％以上であることが好ましく、１．８質量％以上であることがより好ましく、２．５質量％以上であることが更に好ましく、３．０質量％以上であることがより更に好ましい。粘結剤組成物中の硬化促進剤の含有量は、硬化促進剤のフラン樹脂への溶解性の観点及び鋳型の最終強度を向上させる観点から、６３質量％以下であることが好ましく、５０質量％以下であることがより好ましく、４０質量％以下であることが更に好ましい。 From the viewpoint of improving the final strength of the mold, the content of the curing accelerator in the binder composition is preferably 0.5% by mass or more, more preferably 1.8% by mass or more. , 2.5% by mass or more, even more preferably 3.0% by mass or more. The content of the curing accelerator in the binder composition is preferably 63% by mass or less from the viewpoint of solubility of the curing accelerator in the furan resin and improving the final strength of the mold, and is preferably 50% by mass or less. %, More preferably 40% by weight or less.
　硬化促進剤（１）としては、２，５－ビスヒドロキシメチルフラン、２，５－ビスメトキシメチルフラン、２，５－ビスエトキシメチルフラン、２－ヒドロキシメチル－５－メトキシメチルフラン、２－ヒドロキシメチル－５－エトキシメチルフラン、２－メトキシメチル－５－エトキシメチルフランが挙げられる。なかでも、最終的な鋳型強度を向上させる観点から、２，５－ビスヒドロキシメチルフランを使用するのが好ましい。 Examples of the curing accelerator (1) include 2,5-bishydroxymethylfuran, 2,5-bismethoxymethylfuran, 2,5-bisethoxymethylfuran, 2-hydroxymethyl-5-methoxymethylfuran, and 2-hydroxymethylfuran. Methyl-5-ethoxymethylfuran and 2-methoxymethyl-5-ethoxymethylfuran are exemplified. Among them, it is preferable to use 2,5-bishydroxymethylfuran from the viewpoint of improving the final mold strength.
　フェノール誘導体としては、例えばレゾルシン、クレゾール、ヒドロキノン、フロログルシノール、メチレンビスフェノール等が挙げられる。なかでも、鋳型の深部硬化性の観点及び最終的な鋳型強度を向上させる観点から、レゾルシンが好ましい。粘結剤組成物中の前記フェノール誘導体の含有量は、フェノール誘導体のフラン樹脂への溶解性の観点及び、最終的な鋳型強度を向上させる観点から、１～２５質量％であることが好ましく、２～１５質量％であることがより好ましく、３～１０質量％であることが更に好ましい。なかでも、レゾルシンを用いる場合は、粘結剤組成物中のレゾルシンの含有量は、レゾルシンのフラン樹脂への溶解性の観点、及び最終的な鋳型強度を向上させる観点から、１～１０質量％であることが好ましく、２～７質量％であることがより好ましく、３～６質量％であることが更に好ましい。 Examples of the phenol derivative include resorcin, cresol, hydroquinone, phloroglucinol, and methylenebisphenol. Above all, resorcinol is preferable from the viewpoint of the deep curing property of the mold and the viewpoint of improving the final mold strength. The content of the phenol derivative in the binder composition is preferably 1 to 25% by mass from the viewpoint of the solubility of the phenol derivative in the furan resin and from the viewpoint of improving the final mold strength. The content is more preferably 2 to 15% by mass, and still more preferably 3 to 10% by mass. Among them, when resorcin is used, the content of resorcin in the binder composition is from 1 to 10% by mass from the viewpoint of solubility of resorcin in furan resin and improving final mold strength. Is preferably 2 to 7% by mass, and more preferably 3 to 6% by mass.
　芳香族ジアルデヒドとしては、テレフタルアルデヒド、フタルアルデヒド及びイソフタルアルデヒド等、並びにそれらの誘導体等が挙げられる。それらの誘導体とは、基本骨格としての２つのホルミル基を有する芳香族化合物の芳香環にアルキル基等の置換基を有する化合物等を意味する。鋳型の割れを防ぐ観点から、テレフタルアルデヒド及びテレフタルアルデヒドの誘導体が好ましく、テレフタルアルデヒドがより好ましい。粘結剤組成物中の芳香族ジアルデヒドの含有量は、芳香族ジアルデヒドをフラン樹脂に十分に溶解させる観点、及び芳香族ジアルデヒド自体の臭気を抑制する観点から、好ましくは０．１～１５質量％であり、より好ましくは０．５～１０質量％であり、更に好ましくは１～５質量％である。 Aromatic dialdehydes include terephthalaldehyde, phthalaldehyde, isophthalaldehyde, and the like, and derivatives thereof. These derivatives mean compounds having a substituent such as an alkyl group on the aromatic ring of an aromatic compound having two formyl groups as the basic skeleton. From the viewpoint of preventing the mold from cracking, terephthalaldehyde and terephthalaldehyde derivatives are preferable, and terephthalaldehyde is more preferable. The content of the aromatic dialdehyde in the binder composition is preferably 0.1 to 0.1 from the viewpoint of sufficiently dissolving the aromatic dialdehyde in the furan resin and suppressing the odor of the aromatic dialdehyde itself. The content is 15% by mass, more preferably 0.5 to 10% by mass, and still more preferably 1 to 5% by mass.
　タンニン類としては、縮合タンニンや加水分解型タンニンが挙げられる。これら縮合タンニンや加水分解型タンニンの例としては、ピロガロール骨格やレゾルシン骨格を持つタンニンが挙げられる。また、これらタンニン類を含有する樹皮抽出物や植物由来の葉、実、種、植物に寄生した虫こぶ等の天然物からの抽出物を添加しても構わない。 The tannins include condensed tannins and hydrolyzed tannins. Examples of these condensed tannins and hydrolyzable tannins include tannins having a pyrogallol skeleton and a resorcinol skeleton. In addition, bark extracts containing these tannins or extracts from natural products such as plant-derived leaves, fruits, seeds, and galls parasitic on plants may be added.
〔その他の添加剤〕
　前記粘結剤組成物中には、更にシランカップリング剤等の添加剤が含まれていてもよい。例えば、粘結剤組成物中にシランカップリング剤が含まれていると、得られる鋳型の最終強度をより向上させることができるため好ましい。シランカップリング剤としては、Ｎ－β－（アミノエチル）－γ－アミノプロピルメチルジメトキシシラン、Ｎ－β－（アミノエチル）－γ－アミノプロピルトリメトキシシラン、Ｎ－β－（アミノエチル）－γ－アミノプロピルトリエトキシシラン、３－アミノプロピルトリメトキシシラン等のアミノシランや、３－グリシドキシプロピルトリメトキシシラン、３－グリシドキシプロピルトリエトキシシラン、３－グリシドキシプロピルメチルジエトキシシラン、３－グリシドキシプロピルトリエトキシシラン等のエポキシシラン、ウレイドシラン、メルカプトシラン、スルフィドシラン、メタクリロキシシラン、アクリロキシシランなどが用いられる。好ましくは、アミノシラン、エポキシシラン、ウレイドシランである。より好ましくはアミノシラン、エポキシシランであり、更に好ましくはアミノシランである。アミノシランの中でも、Ｎ－β－（アミノエチル）－γ－アミノプロピルメチルジメトキシシランが好ましい。シランカップリング剤の粘結剤組成物中の含有量は、鋳型の最終強度を向上させる観点から、０．０１質量％以上が好ましく、０．０５質量％以上がより好ましい。シランカップリング剤の粘結剤組成物中の含有量は、同様の観点から、１．０質量％以下が好ましく、０．５質量％以下がより好ましい。 [Other additives]
The binder composition may further contain an additive such as a silane coupling agent. For example, it is preferable to include a silane coupling agent in the binder composition because the final strength of the obtained mold can be further improved. Examples of the silane coupling agent include N-β- (aminoethyl) -γ-aminopropylmethyldimethoxysilane, N-β- (aminoethyl) -γ-aminopropyltrimethoxysilane, N-β- (aminoethyl)- aminosilanes such as γ-aminopropyltriethoxysilane and 3-aminopropyltrimethoxysilane, 3-glycidoxypropyltrimethoxysilane, 3-glycidoxypropyltriethoxysilane, and 3-glycidoxypropylmethyldiethoxysilane And epoxyglycols such as 3-glycidoxypropyltriethoxysilane, ureidosilane, mercaptosilane, sulfidesilane, methacryloxysilane and acryloxysilane. Preferred are aminosilane, epoxysilane and ureidosilane. More preferred are aminosilane and epoxysilane, and even more preferred are aminosilane. Among aminosilanes, N-β- (aminoethyl) -γ-aminopropylmethyldimethoxysilane is preferred. From the viewpoint of improving the final strength of the mold, the content of the silane coupling agent in the binder composition is preferably 0.01% by mass or more, and more preferably 0.05% by mass or more. From the same viewpoint, the content of the silane coupling agent in the binder composition is preferably equal to or less than 1.0% by mass, and more preferably equal to or less than 0.5% by mass.
　前記粘結剤組成物中には、経済的コストを抑制する観点から、メタノール、エタノール、エチレングリコール、プロピレングリコール、及びグリセリンからなる群より選ばれる１種以上のアルコールが含まれていてもよい。当該アルコールの含有量は、１質量％以上が好ましく、２質量％以上がより好ましい。前記アルコールの含有量は、鋳型の強度低下を抑制する観点から、１０質量％以下が好ましい。また、前記アルコールの含有量は、低温環境下での凍結を防止する観点、及び鋳型の強度低下を抑制する観点から、１～１０質量％が好ましく、２～１０質量％がより好ましい。 か ら The binder composition may contain one or more alcohols selected from the group consisting of methanol, ethanol, ethylene glycol, propylene glycol, and glycerin from the viewpoint of reducing economic costs. The content of the alcohol is preferably 1% by mass or more, more preferably 2% by mass or more. The content of the alcohol is preferably 10% by mass or less from the viewpoint of suppressing a decrease in strength of the mold. Further, the content of the alcohol is preferably 1 to 10% by mass, more preferably 2 to 10% by mass, from the viewpoint of preventing freezing in a low-temperature environment and suppressing the reduction in strength of the mold.
　前記粘結剤組成物中には、鋳型強度向上の観点から、尿素が含まれていてもよい。前記尿素とは、ホルムアルデヒドやフルフリルアルコール等と縮合反応していない尿素であり、未反応分として残存したものでも、別途添加されたものでも何れでも良い。前記粘結剤組成物中の前記尿素の含有量は、鋳型強度向上の観点、ホルムアルデヒド濃度を低減させる観点から、０．５質量％以上が好ましく、０．８質量％以上がより好ましく、１．０質量％以上が更に好ましい。前記粘結剤組成物中の前記尿素の含有量は、硬化速度を向上させる観点、粘結剤組成物の保存安定性の観点から、１０質量％以下が好ましく、６．０質量％以下がより好ましく４．５質量％以下が更に好ましい。 尿素 The binder composition may contain urea from the viewpoint of improving mold strength. The urea is urea that has not been condensed with formaldehyde, furfuryl alcohol, or the like, and may be either remaining as an unreacted component or separately added. The content of the urea in the binder composition is preferably 0.5% by mass or more, more preferably 0.8% by mass or more, from the viewpoint of improving the mold strength and reducing the formaldehyde concentration. 0 mass% or more is more preferable. The content of the urea in the binder composition is preferably 10% by mass or less, more preferably 6.0% by mass or less, from the viewpoint of improving the curing speed and the storage stability of the binder composition. It is more preferably at most 4.5% by mass.
　なお、粘結剤組成物中の尿素は、以下のようなＬＣ／ＭＳ分析操作により測定することができる。サンプルの調製は、アセトン／水＝５０／５０の混合溶液で１００倍希釈し、さらに移動相で１００倍希釈する。
（ＬＣ／ＭＳ分析条件）
カラム：Ｕｎｉｓｏｎ　ＵＫ－Ａｍｉｎｏ　ＨＴ
移動相：０．１％　ＴＦＡ　アセトニトリル／水＝９５／５
流量：０．２ｍＬ／ｍｉｎ
カラム温度：４０℃
ＭＳ：ＳＩＭ  ｍ／ｚ：６１．０　［Ｍ＋Ｈ］＋ The urea in the binder composition can be measured by the following LC / MS analysis operation. For sample preparation, the sample is diluted 100-fold with a mixed solution of acetone / water = 50/50, and further diluted 100-fold with a mobile phase.
(LC / MS analysis conditions)
Column: Unison UK-Amino HT
Mobile phase: 0.1% TFA acetonitrile / water = 95/5
Flow rate: 0.2 mL / min
Column temperature: 40 ° C
MS: SIM m / z: 61.0 [M + H] +
〔フェノール樹脂〕
　前記粘結剤組成物は、鋳型の可とう性を向上させる観点及び鋳型の最終強度を向上させる観点から、フェノール樹脂を含有してもよい。フェノール樹脂としては、重量平均分子量が１０００以上５０００以下のものが挙げられる。 (Phenol resin)
The binder composition may contain a phenol resin from the viewpoint of improving the flexibility of the mold and improving the final strength of the mold. Examples of the phenol resin include those having a weight average molecular weight of 1,000 to 5,000.
　前記フェノール樹脂の重量平均分子量は、鋳型の可とう性を向上させる観点及び鋳型の最終強度を向上させる観点から、１０００以上が好ましく、１４００以上がより好ましい。同様の観点から、５０００以下が好ましく、２５００以下がより好ましい。よって、１０００～５０００が好ましく、１４００～２５００がより好ましい。 重量 The phenolic resin has a weight average molecular weight of preferably 1000 or more, more preferably 1400 or more, from the viewpoint of improving the mold flexibility and the final strength of the mold. From the same viewpoint, it is preferably 5000 or less, more preferably 2500 or less. Therefore, it is preferably from 1,000 to 5,000, more preferably from 1,400 to 2,500.
　前記フェノール樹脂の分散度（重量平均分子量／数平均分子量の比）は、鋳型の可とう性を向上させる観点及び鋳型の最終強度を向上させる観点から、１．２以上が好ましく、１．８以上がより好ましい。前記フェノール樹脂の重量平均分子量は、粘結剤組成物の保存安定性を向上させる観点、鋳型の可とう性を向上させる観点及び鋳型の最終強度を向上させる観点から、５．０以下が好ましく、３．５以下がより好ましい。よって、１．２～５．０が好ましく、１．８～３．５がより好ましい。 The dispersity (the ratio of weight average molecular weight / number average molecular weight) of the phenol resin is preferably 1.2 or more, and more preferably 1.8 or more, from the viewpoint of improving the flexibility of the mold and improving the final strength of the mold. Is more preferred. The weight average molecular weight of the phenolic resin is preferably 5.0 or less from the viewpoint of improving the storage stability of the binder composition, improving the flexibility of the mold and improving the final strength of the mold, 3.5 or less is more preferable. Therefore, 1.2 to 5.0 is preferable, and 1.8 to 3.5 is more preferable.
　前記フェノール樹脂としては、従来公知のものが使用でき、例えば、レゾール型フェノール樹脂、ノボラック型フェノール樹脂、及び特願２００９―２９２８６２号公報に記載されているような構造を有するフェノール樹脂からなる群から選ばれる１種からなるものや、これらの群から選ばれる２種以上の混合物からなるものが使用できる。 As the phenol resin, conventionally known ones can be used. For example, a resol type phenol resin, a novolak type phenol resin, and a phenol resin having a structure as described in Japanese Patent Application No. 2009-292862 are used. Those composed of one selected from the group or those composed of a mixture of two or more selected from these groups can be used.
　なお、一般に、レゾール型フェノール樹脂を得るために用いるフェノール類としては、フェノール、クレゾール、キシレノール等が挙げられるが、これらの中でも鋳型の可とう性を向上させる観点及び鋳型の最終強度を向上させる観点からフェノールが好ましい。レゾール型フェノール樹脂を得るために用いるアルデヒド類としては、例えば、ホルムアルデヒド、グリオキザール、パラホルムアルデヒド、フルフラール、５－ヒドロキシメチルフルフラール等が挙げられるが、鋳型の可とう性を向上させる観点及び鋳型の最終強度を向上させる観点からパラホルムアルデヒドが好ましい。レゾール型フェノール樹脂を得るために用いる塩基性触媒としては、例えば、水酸化カリウム、水酸化ナトリウム等が挙げられる。 In addition, in general, phenols used to obtain a resol type phenol resin include phenol, cresol, xylenol, and the like, but among these, a viewpoint of improving the flexibility of the mold and a viewpoint of improving the final strength of the mold. To phenol is preferred. Examples of the aldehydes used for obtaining the resole type phenol resin include formaldehyde, glyoxal, paraformaldehyde, furfural, 5-hydroxymethylfurfural and the like, but from the viewpoint of improving the flexibility of the mold and the final strength of the mold. Paraformaldehyde is preferred from the viewpoint of improving the odor. Examples of the basic catalyst used for obtaining the resole type phenol resin include potassium hydroxide, sodium hydroxide and the like.
　また、一般に、ノボラック型フェノール樹脂を得るために用いるフェノール類及びアルデヒド類としては、レゾール型フェノール樹脂と同様のものが挙げられる。 フ ェ ノ ー ル Generally, the phenols and aldehydes used to obtain a novolak phenol resin include the same phenols and aldehydes as the resol phenol resin.
　フェノール樹脂組成物を製造する際、フェノール樹脂以外に原料、原料に含まれる水、反応中に生成する水が含まれるが、経済性の観点から除去しなくても良い。 When producing the phenolic resin composition, raw materials, water contained in the raw materials, and water generated during the reaction are contained in addition to the phenolic resin, but may not be removed from the viewpoint of economy.
　前記フェノール樹脂の中でも、溶解性の観点、鋳型の可とう性を向上させる観点及び鋳型の最終強度を向上させる観点から、レゾール型フェノール樹脂を使用するのが好ましい。 中 で も Among the phenolic resins, it is preferable to use a resol-type phenolic resin from the viewpoint of solubility, improving the flexibility of the mold, and improving the final strength of the mold.
　前記粘結剤組成物における前記フェノール樹脂の含有量は、溶解性の観点、鋳型の可とう性を向上させる観点及び鋳型の最終強度を向上させる観点から、２質量％以上３５質量％以下である。 The content of the phenol resin in the binder composition is 2% by mass or more and 35% by mass or less from the viewpoint of solubility, improving the flexibility of the mold, and improving the final strength of the mold. .
　前記粘結剤組成物における前記フェノール樹脂の含有量は、鋳型の可とう性を向上させる観点及び鋳型の最終強度を向上させる観点から、８質量％以上がより好ましい。前記粘結剤組成物における前記フェノール樹脂の含有量は、溶解性の観点、鋳型の可とう性を向上させる観点及び鋳型の最終強度を向上させる観点から、２０質量％以下がより好ましい。よって、８～２０質量％がより好ましい。 含有 The content of the phenol resin in the binder composition is more preferably 8% by mass or more from the viewpoint of improving the mold flexibility and the final strength of the mold. The content of the phenol resin in the binder composition is more preferably 20% by mass or less from the viewpoint of solubility, improving the flexibility of the mold, and improving the final strength of the mold. Therefore, 8 to 20% by mass is more preferable.
　前記粘結剤組成物中の前記フラン樹脂と前記フェノール樹脂の合計含有量は、鋳型の最終強度を向上させる観点から、５０質量％以上が好ましい。前記粘結剤組成物中の前記フラン樹脂と前記フェノール樹脂の合計含有量は、鋳型の最終強度を向上させる観点から、９５質量％以下が好ましい。よって、５０～９５質量％が好ましい。 合計 The total content of the furan resin and the phenol resin in the binder composition is preferably 50% by mass or more from the viewpoint of improving the final strength of the mold. The total content of the furan resin and the phenol resin in the binder composition is preferably 95% by mass or less from the viewpoint of improving the final strength of the mold. Therefore, 50 to 95% by mass is preferable.
　前記粘結剤組成物は自硬性鋳型の造型に好適に用いられる。ここで自硬性鋳型とは、砂に粘結剤組成物と硬化剤組成物を混合すると、時間の経過と共に重合反応が進行し、鋳型が硬化する鋳型である。その際に用いられる砂の温度としては、－２０℃～５０℃の範囲であり、好ましくは０℃～４０℃である。このような温度の砂に対して、それに適した量の硬化剤を選択し砂に添加する事で、鋳型を適切に硬化できる。 The binder composition is suitably used for molding a self-hardening mold. Here, the self-hardening mold is a mold in which when a binder composition and a curing agent composition are mixed with sand, a polymerization reaction proceeds with the passage of time and the mold is cured. The temperature of the sand used at that time is in the range of −20 ° C. to 50 ° C., preferably 0 ° C. to 40 ° C. For a sand having such a temperature, a proper amount of a curing agent is selected and added to the sand, whereby the mold can be appropriately cured.
＜鋳型用組成物＞
　前記粘結剤組成物は、耐火性粒子及び硬化剤組成物と混合して鋳型用組成物とすることができる。本実施形態の鋳型用組成物は、前記粘結剤組成物、耐火性粒子及び硬化剤組成物を含有する。 <Composition for mold>
The binder composition can be mixed with the refractory particles and the hardener composition to form a mold composition. The composition for a mold of the present embodiment contains the binder composition, the refractory particles, and the curing agent composition.
〔耐火性粒子〕
　前記耐火性粒子としては、珪砂、クロマイト砂、ジルコン砂、オリビン砂、アルミナ砂、ムライト砂、合成ムライト砂等の従来公知のものを使用でき、また、使用済みの耐火性粒子を回収したものや再生処理したものなども使用できる。 (Refractory particles)
As the refractory particles, silica sand, chromite sand, zircon sand, olivine sand, alumina sand, mullite sand, conventionally known ones such as synthetic mullite sand can be used, and those obtained by collecting used refractory particles and Those that have been reproduced can also be used.
〔硬化剤組成物〕
　前記硬化剤組成物は、前記粘結剤組成物を硬化させる硬化剤を含有するものであれば特に限定なく用いることができる。当該硬化剤としては酸系硬化剤が例示でき、キシレンスルホン酸（特に、ｍ－キシレンスルホン酸）やトルエンスルホン酸（特に、ｐ－トルエンスルホン酸）、メタンスルホン酸等のスルホン酸系化合物、リン酸、酸性リン酸エステル等のリン酸系化合物、硫酸等を含む酸性水溶液など、従来公知のものを１種以上が使用できる。これらの化合物は、取り扱い性の観点から水溶液であることが好ましい。更に、硬化剤中にアルコール類、エーテルアルコール類及びエステル類よりなる群から選ばれる１種以上の溶剤や、カルボン酸類を含有させることができる。 (Curing agent composition)
The curing agent composition can be used without any particular limitation as long as it contains a curing agent for curing the binder composition. Examples of the curing agent include acid-based curing agents, such as sulfonic acid compounds such as xylene sulfonic acid (particularly, m-xylene sulfonic acid), toluene sulfonic acid (particularly, p-toluene sulfonic acid), methane sulfonic acid, and the like. One or more conventionally known compounds such as an acid, a phosphoric acid compound such as an acidic phosphoric ester, an acidic aqueous solution containing sulfuric acid and the like can be used. These compounds are preferably aqueous solutions from the viewpoint of handleability. Further, the curing agent may contain one or more solvents selected from the group consisting of alcohols, ether alcohols and esters, and carboxylic acids.
　前記硬化剤組成物中の硬化剤の含有量は、最終的な鋳型強度向上の観点から、５～５０質量％であることが好ましく、１０～４０質量％であることがより好ましい。 か ら The content of the curing agent in the curing agent composition is preferably from 5 to 50% by mass, and more preferably from 10 to 40% by mass, from the viewpoint of ultimately improving the strength of the mold.
　前記鋳型用組成物において、耐火性粒子１００質量部に対して、前記粘結剤組成物０．５～３．０質量部、前記硬化剤組成物０．０７～２．０質量部含有することが好ましい。 The composition for a mold contains 0.5 to 3.0 parts by mass of the binder composition and 0.07 to 2.0 parts by mass of the curing agent composition based on 100 parts by mass of the refractory particles. Is preferred.
　また、鋳型用組成物中の硬化剤組成物の含有量は、鋳型強度向上の観点から粘結剤組成物１．０質量部に対して、好ましくは０．１質量部以上、より好ましくは０．１４質量部以上、更に好ましくは０．２質量部以上であり、好ましくは０．８質量部以下、より好ましくは０．６質量部以下、更により好ましくは０．４質量部以下である。以上を総合すると、鋳型用組成物中の硬化剤組成物の含有量は、鋳型強度向上の観点から粘結剤組成物１．０質量部に対して、好ましくは０．１～０．８質量部、より好ましくは０．１４～０．６質量部、より更に好ましくは０．２～０．４質量部である。 Further, the content of the curing agent composition in the composition for a mold is preferably 0.1 part by mass or more, more preferably 0 part by mass, based on 1.0 part by mass of the binder composition from the viewpoint of improving the mold strength. .14 parts by mass or more, more preferably 0.2 parts by mass or more, preferably 0.8 parts by mass or less, more preferably 0.6 parts by mass or less, still more preferably 0.4 parts by mass or less. In summary, the content of the curing agent composition in the composition for a mold is preferably 0.1 to 0.8 parts by mass with respect to 1.0 part by mass of the binder composition from the viewpoint of improving mold strength. Parts, more preferably 0.14 to 0.6 parts by mass, even more preferably 0.2 to 0.4 parts by mass.
＜鋳型の製造方法＞
　前記鋳型用組成物を硬化させることによって鋳型を製造することができる。本実施形態の鋳型の製造方法において、従来の鋳型の製造プロセスをそのまま利用して鋳型を製造することができる。好ましい鋳型の製造方法として、耐火性粒子と前記鋳型造型用粘結剤組成物と、前記鋳型造型用粘結剤組成物を硬化させる硬化剤組成物とを混合して鋳型用組成物を得る混合工程、及び前記鋳型用組成物を型枠に詰め、当該鋳型用組成物を硬化する硬化工程を有する鋳型の製造方法が挙げられる。 <Mold manufacturing method>
A mold can be produced by curing the mold composition. In the method for manufacturing a mold according to the present embodiment, the mold can be manufactured by using the conventional mold manufacturing process as it is. As a preferred method for producing a mold, mixing the refractory particles, the binder composition for mold molding, and a curing agent composition for curing the binder composition for mold molding to obtain a composition for mold. And a method for producing a mold having a curing step of packing the mold composition into a mold and curing the mold composition.
　前記混合工程は、耐火性粒子と硬化剤組成物を含有する鋳型造型用硬化剤組成物とを混合する第１混合工程、及び第１混合工程後に得られた混合物に鋳型造型用粘結剤組成物を混合する第２混合工程を有するのが好ましい。 The mixing step includes a first mixing step of mixing the refractory particles and a curing agent composition for mold molding containing the curing agent composition, and a binder composition for mold molding added to the mixture obtained after the first mixing step. It is preferable to have a second mixing step of mixing the substances.
　前記混合工程では、本実施形態の効果を阻害しない程度に酸硬化性樹脂、硬化促進剤、水、シランカップリング剤等の添加剤、酸性物質、及び溶剤等を添加してもよい。 In the mixing step, an acid-curable resin, a curing accelerator, water, additives such as a silane coupling agent, an acidic substance, and a solvent may be added to such an extent that the effects of the present embodiment are not impaired.
　前記混合工程において、各原料を混合する方法としては、公知一般の手法を用いることが出来、例えば、バッチミキサーにより各原料を添加して混練する方法や、連続ミキサーに各原料を供給して混練する方法が挙げられる。 In the mixing step, as a method of mixing the respective raw materials, a known general method can be used, for example, a method of adding and mixing the respective raw materials by a batch mixer, or a method of supplying the respective raw materials to a continuous mixer and kneading. Method.
　以下、本発明を具体的に示す実施例等について説明する。 Hereinafter, examples and the like specifically illustrating the present invention will be described.
＜実施例１～９、比較例１～４＞
〔フラン樹脂組成物の調製〕
　三ツ口フラスコにフルフリルアルコール１００質量部とパラホルムアルデヒド３５質量部と尿素１３質量部を混合し２５質量％水酸化ナトリウム水溶液でｐＨ９に調整した。反応混合物を１００℃に昇温後、同温度で１時間反応させた。３７質量％塩酸でｐＨ４．５に調整し、更に１００℃で１時間反応させた。その後、２５質量％水酸化ナトリウム水溶液でｐＨ７に調整し、尿素５質量部を添加して、１００℃で３０分反応させ、フラン樹脂組成物を得た。フラン樹脂組成物の組成は、尿素変性フラン樹脂７１．７質量％、フルフリルアルコール１９．５質量％、水８．８質量％であった。 <Examples 1 to 9, Comparative Examples 1 to 4>
(Preparation of furan resin composition)
In a three-necked flask, 100 parts by mass of furfuryl alcohol, 35 parts by mass of paraformaldehyde, and 13 parts by mass of urea were mixed and adjusted to pH 9 with a 25% by mass aqueous sodium hydroxide solution. After the temperature of the reaction mixture was raised to 100 ° C., it was reacted at the same temperature for 1 hour. The mixture was adjusted to pH 4.5 with 37% by mass hydrochloric acid, and further reacted at 100 ° C. for 1 hour. Thereafter, the pH was adjusted to 7 with a 25% by mass aqueous sodium hydroxide solution, 5 parts by mass of urea was added, and the mixture was reacted at 100 ° C. for 30 minutes to obtain a furan resin composition. The composition of the furan resin composition was 71.7% by mass of a urea-modified furan resin, 19.5% by mass of furfuryl alcohol, and 8.8% by mass of water.
〔デキストロース当量〕
　試料２．５ｇを正確に量り、水に溶かして２００ｍＬとする。この液１０ｍＬを正確に量り、０．０４ｍｏｌ／Ｌヨウ素溶液１０ｍＬと、０．０４ｍｏｌ／Ｌ水酸化ナトリウム溶液１５ｍＬを加えて２０分間暗所に放置した。次に、２ｍｏｌ／Ｌ塩酸を５ｍＬ加えて混和した後、０．０４ｍｏｌ／Ｌチオ硫酸ナトリウム溶液で滴定した。滴定の終点近くで液が微黄色になったら、でんぷん指示薬２滴を加えて滴定を継続し、液の色が消失した時点を滴定の終点とした。これとは別に空試験を行い、次式によりデキストロース当量（ＤＥ）を求めた。
　ＤＥ＝（ｂ－ａ）×ｆ×３．６０２／（１／１０００）／（２００／１０）／[Ａ×（１００－Ｂ）×１００]×１００
〔式中、ａは滴定値（ｍＬ）を示し、ｂはブランク値（ｍＬ）を示し、ｆはチオ硫酸ナトリウム溶液のファクター値を示し、Ａは試料の秤取量（ｍｇ）を示し、Ｂは試料の水分値（％）を示す。〕 [Dextrose equivalent]
Precisely weigh 2.5 g of sample and dissolve in water to make 200 mL. 10 mL of this solution was accurately measured, 10 mL of a 0.04 mol / L iodine solution and 15 mL of a 0.04 mol / L sodium hydroxide solution were added, and the mixture was left in a dark place for 20 minutes. Next, 5 mL of 2 mol / L hydrochloric acid was added and mixed, and then titrated with a 0.04 mol / L sodium thiosulfate solution. When the solution became slightly yellow near the end point of the titration, 2 drops of a starch indicator were added and the titration was continued, and the time when the color of the solution disappeared was defined as the end point of the titration. Separately, a blank test was performed, and dextrose equivalent (DE) was determined by the following equation.
DE = (ba) × f × 3.602 / (1/1000) / (200/10) / [A × (100−B) × 100] × 100
[Where a represents a titration value (mL), b represents a blank value (mL), f represents a factor value of a sodium thiosulfate solution, A represents a sample weighed amount (mg), and B represents Indicates the moisture value (%) of the sample. ]
〔加水分解澱粉の溶解性〕
　表１に記載の各粘結剤組成物を入れたガラス製スクリュー管に下記１～４の操作を順番に実施して、粘結剤組成物を溶解させた。数字が小さい操作で溶解したものほど溶解性が高いとした。ここで、溶解したとは各操作を実施したあとにガラス製スクリュー管を目視観察し、粘結剤組成物が均一透明液体になった状態を言う。結果を表１に示す。
１：２５℃の水中で１Ｈｒ超音波処理（３７ｋＨｚ）
２：５０℃の水中で１Ｈｒ超音波処理（３７ｋＨｚ）
３：５０℃の水中で２Ｈｒ超音波処理（３７ｋＨｚ）
４：５０℃の水中で４Ｈｒ超音波処理（３７ｋＨｚ）
５：不溶（粘結剤組成物中で加水分解澱粉が相分離） (Solubility of hydrolyzed starch)
The following operations 1 to 4 were sequentially performed on a glass screw tube containing each binder composition shown in Table 1 to dissolve the binder composition. The smaller the number, the higher the solubility. Here, the term "dissolved" means a state in which the glass screw tube is visually observed after each operation, and the binder composition becomes a uniform transparent liquid. Table 1 shows the results.
1: Hr ultrasonic treatment in water at 25 ° C (37kHz)
2: 1Hr sonication in water at 50 ° C (37kHz)
3: 2Hr sonication in water at 50 ° C (37kHz)
4: 4Hr sonication in water at 50 ° C (37kHz)
5: Insoluble (hydrolyzed starch phase-separates in binder composition)
〔粘結剤組成物の保存安定性〕
　上記操作で加水分解澱粉を溶解させた各粘結剤組成物を常温（２５℃）で１週間放置し、下記基準で目視評価した。
○：粘結剤組成物中に加水分解澱粉が均一に溶解
×：粘結剤組成物中で加水分解澱粉が相分離 (Storage stability of binder composition)
Each binder composition in which the hydrolyzed starch was dissolved by the above operation was allowed to stand at normal temperature (25 ° C.) for one week, and visually evaluated according to the following criteria.
：: The hydrolyzed starch is uniformly dissolved in the binder composition. X: The hydrolyzed starch is phase-separated in the binder composition.
〔鋳型強度〕
　２５℃、５５％ＲＨの条件下で、フラン再生珪砂１００質量部に対し、硬化剤組成物（カオーライトナーＣ－１７：花王クエーカー社製）０．４０質量部を添加し、次いで表１に示した成分を予め所定量加えて混合して得られた粘結剤組成物０．８質量部を添加し、これらを混合して各実施例及び比較例に係る鋳型用組成物を得た。得られた鋳型用組成物を直径５０ｍｍ、高さ５０ｍｍの円柱状のテストピース枠にそれぞれ充填し、２時間後に抜型を行い、充填から２４時間後に、ＪＩＳＺ　２６０４－１９７６に記載された方法で圧縮強度（ＭＰａ）を測定した。尚、圧縮強度を比較するにあたり、鋳型用組成物を調製する際に用いた粘結剤組成物は、常温で１週間保存したものを振とうした後に使用した。結果を表１に示す。実施例１～９は、４．７ＭＰａ以上であった。一方、比較例１～４は、４．４ＭＰａ以下であり圧縮強度は低かった。これは、比較例では粘結剤組成物中で加水分解澱粉が相分離しており、鋳型用組成物中で加水分解澱粉が凝集を起こしていたことが影響したと考えられる。 (Mold strength)
Under the conditions of 25 ° C. and 55% RH, 0.40 parts by mass of a hardener composition (Kao Lightener C-17: manufactured by Kao Quaker Co.) was added to 100 parts by mass of the regenerated furan sand, and the results are shown in Table 1. 0.8 parts by mass of a binder composition obtained by previously adding and mixing a predetermined amount of the above components were added, and these were mixed to obtain mold compositions according to Examples and Comparative Examples. The obtained composition for a mold was filled in a cylindrical test piece frame having a diameter of 50 mm and a height of 50 mm, and after 2 hours, the mold was removed. After 24 hours from the filling, the composition was compressed by the method described in JISZ 2604-1976. The strength (MPa) was measured. In comparing the compressive strengths, the binder composition used in preparing the composition for a mold was used after shaking the one that had been stored at room temperature for one week. Table 1 shows the results. In Examples 1 to 9, the pressure was 4.7 MPa or more. On the other hand, Comparative Examples 1 to 4 had a compression strength of 4.4 MPa or less and low compressive strength. This is considered to be due to the fact that in the comparative example, the hydrolyzed starch was phase-separated in the binder composition, and the hydrolyzed starch was agglomerated in the mold composition.
Figure JPOXMLDOC01-appb-T000002
  
Figure JPOXMLDOC01-appb-T000002
  

Claims (4)

  1. 　フラン樹脂と、水と、加水分解澱粉とを含有し、
    　前記フラン樹脂と前記加水分解澱粉との質量比（前記フラン樹脂の質量／前記加水分解澱粉の質量）が２０～９５であり、前記加水分解澱粉のデキストロース当量が６０以上である鋳型造型用粘結剤組成物。     Containing a furan resin, water, and hydrolyzed starch,
    A binding ratio for the furan resin and the hydrolyzed starch (mass of the furan resin / mass of the hydrolyzed starch) of 20 to 95, and a dextrose equivalent of the hydrolyzed starch of 60 or more; Composition.
  2. 　前記加水分解澱粉の含有量が１～２０質量％である、請求項１に鋳型造型用粘結剤組成物。 に The binder composition for mold making according to claim 1, wherein the content of the hydrolyzed starch is 1 to 20% by mass.
  3. 　耐火性粒子と、請求項１又は２に記載の鋳型造型用粘結剤組成物と、当該鋳型造型用粘結剤組成物を硬化させる硬化剤を含む硬化剤組成物とを含有する鋳型用組成物。 A mold composition comprising refractory particles, the binder composition for mold molding according to claim 1 or 2, and a curing agent composition containing a curing agent for curing the binder composition for mold molding. Stuff.
  4. 　耐火性粒子と、請求項１又は２に記載の鋳型造型用粘結剤組成物と、当該鋳型造型用粘結剤組成物を硬化させる硬化剤を含む硬化剤組成物とを混合して鋳型用組成物を得る混合工程、及び前記鋳型用組成物を型枠に詰め、当該鋳型用組成物を硬化する硬化工程を含む鋳型の製造方法。 Mixing the refractory particles, the binder composition for mold molding according to claim 1 or 2, and a curing agent composition containing a curing agent for curing the binder composition for mold molding, for a mold. A method for producing a mold, comprising: a mixing step of obtaining a composition; and a curing step of filling the mold composition into a mold and curing the mold composition.
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Citations (9)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS4941104B1 (en) * 1970-10-13 1974-11-07
JPS56500010A (en) * 1979-02-27 1981-01-08
JPS61235034A (en) * 1985-04-10 1986-10-20 Kao Corp Binder composition for casting mold
JPS63174754A (en) * 1987-01-14 1988-07-19 Sadaji Nagabori Method and apparatus for batch production of sand mold or core for casting suitable for non-coating casting
JPS63174752A (en) * 1987-01-14 1988-07-19 Sadaji Nagabori Method and apparatus for continuous production of sand mold or core for casting suitable for non-coating casting
JPH11129054A (en) * 1997-10-30 1999-05-18 Gun Ei Chem Ind Co Ltd Component for making mold and mold manufacture
JPH11138234A (en) * 1997-10-31 1999-05-25 Gun Ei Chem Ind Co Ltd Composition for forming mold and method for forming mold
JPH11207432A (en) * 1998-01-26 1999-08-03 Gun Ei Chem Ind Co Ltd Molding composition for mold and molding method for mold
JP2013212536A (en) * 2012-03-09 2013-10-17 Kao Corp Binder composition for producing template

Patent Citations (9)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS4941104B1 (en) * 1970-10-13 1974-11-07
JPS56500010A (en) * 1979-02-27 1981-01-08
JPS61235034A (en) * 1985-04-10 1986-10-20 Kao Corp Binder composition for casting mold
JPS63174754A (en) * 1987-01-14 1988-07-19 Sadaji Nagabori Method and apparatus for batch production of sand mold or core for casting suitable for non-coating casting
JPS63174752A (en) * 1987-01-14 1988-07-19 Sadaji Nagabori Method and apparatus for continuous production of sand mold or core for casting suitable for non-coating casting
JPH11129054A (en) * 1997-10-30 1999-05-18 Gun Ei Chem Ind Co Ltd Component for making mold and mold manufacture
JPH11138234A (en) * 1997-10-31 1999-05-25 Gun Ei Chem Ind Co Ltd Composition for forming mold and method for forming mold
JPH11207432A (en) * 1998-01-26 1999-08-03 Gun Ei Chem Ind Co Ltd Molding composition for mold and molding method for mold
JP2013212536A (en) * 2012-03-09 2013-10-17 Kao Corp Binder composition for producing template

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