WO2022220133A1 - Resin composition for molds - Google Patents

Resin composition for molds Download PDF

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Publication number
WO2022220133A1
WO2022220133A1 PCT/JP2022/016177 JP2022016177W WO2022220133A1 WO 2022220133 A1 WO2022220133 A1 WO 2022220133A1 JP 2022016177 W JP2022016177 W JP 2022016177W WO 2022220133 A1 WO2022220133 A1 WO 2022220133A1
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Prior art keywords
mold
resin
phenolic
resin composition
phenolic resin
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PCT/JP2022/016177
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French (fr)
Japanese (ja)
Inventor
鉄山
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旭有機材株式会社
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Priority to JP2022554340A priority Critical patent/JP7247427B2/en
Publication of WO2022220133A1 publication Critical patent/WO2022220133A1/en

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    • 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
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B22—CASTING; POWDER METALLURGY
    • B22C—FOUNDRY MOULDING
    • B22C9/00—Moulds or cores; Moulding processes
    • B22C9/02—Sand moulds or like moulds for shaped castings
    • C—CHEMISTRY; METALLURGY
    • C04—CEMENTS; CONCRETE; ARTIFICIAL STONE; CERAMICS; REFRACTORIES
    • C04B—LIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE; CERAMICS; REFRACTORIES; TREATMENT OF NATURAL STONE
    • C04B24/00—Use of organic materials as active ingredients for mortars, concrete or artificial stone, e.g. plasticisers
    • C04B24/24—Macromolecular compounds
    • C04B24/28—Macromolecular compounds obtained otherwise than by reactions only involving carbon-to-carbon unsaturated bonds
    • C04B24/30—Condensation polymers of aldehydes or ketones
    • C—CHEMISTRY; METALLURGY
    • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
    • C08L—COMPOSITIONS OF MACROMOLECULAR COMPOUNDS
    • C08L61/00—Compositions of condensation polymers of aldehydes or ketones; Compositions of derivatives of such polymers
    • C08L61/04—Condensation polymers of aldehydes or ketones with phenols only

Definitions

  • the present invention relates to a resin composition for casting molds, and more particularly to a resin composition that is advantageously used in the production of casting molds such as shell molds capable of effectively suppressing or preventing the occurrence of casting defects. be.
  • the casting surface deteriorates due to the insertion and seizure of molten metal.
  • the surface of the mold is coated with a coating agent containing graphite, zircon, aluminum oxide, etc.
  • the coating work is a complicated work.
  • there are inherent problems such as deterioration of the disintegration of the mold after casting.
  • Patent Document 1 Patent No. 4656474.
  • a mold is prepared by coating the surface of a refractory aggregate with a thermosetting resin and a carbonaceous material, and casting is performed by pouring molten metal.
  • the carbonaceous material has a fixed carbon content of 50 to 98% by mass, and a mold molded using this resin-coated sand is heated at 1000 ° C. to 240 ° C. It has been proposed that the amount of gas generated when heated for a second is 20 mL or more per 1 cm 3 of the mold.
  • a mold molded using such a resin-coated sand can protect the shell mold (mold) from the high temperature of the molten metal without using a mold wash agent, and improve the casting surface of the casting. It is said that it is possible to
  • the present invention has been made against the background of such circumstances, and the problem to be solved is to effectively suppress or prevent the occurrence of casting defects such as seizure and insertion. It is an object of the present invention to provide a composition for a casting mold, which can advantageously produce a casting mold that can be used. In addition, the present invention provides a casting composition that can advantageously produce a casting mold such as a shell mold that can effectively improve the casting operation without applying a washing agent. This is a problem to be solved.
  • the present invention can be suitably implemented in various aspects as listed below. Adoptable. It should be noted that the aspects and technical features of the present invention are not limited to those described below, and can be recognized based on the inventive idea grasped from the description of the entire specification and the drawings. should be understood.
  • the ratio of the amount of gas generated within 20 seconds from the start of measurement to the total amount of gas generated must be 50% or more.
  • a casting mold resin composition characterized by: (2) The mold resin composition according to aspect (1), wherein the phenolic resin is one or more selected from the group consisting of novolac-type phenolic resins, modified novolac-type phenolic resins and resol-type phenolic resins. thing. (3) The casting mold resin composition according to the aspect (1) or the aspect (2), wherein the carbonization accelerator is an organic phosphoric acid ester and/or an organic halide. (4) The mold resin composition according to any one of the above aspects (1) to (3), which is used for making a mold for casting molten iron. (5) A resin-coated sand comprising the casting mold resin composition according to any one of the aspects (1) to (4) and a refractory aggregate. (6) Molding using the resin-coated sand according to the aspect (5), A mold made by heating and hardening.
  • the cured product containing a specific phenolic resin and a carbonization accelerator and completely cured at 150°C generates gas in a reducing atmosphere at 850°C. It is prepared and configured so that the ratio of the amount of gas generated in 20 seconds from the start of measurement to the total amount of gas generated is 50% or more when the amount is measured.
  • a resin-coated sand (mold-making material) is produced using the resin composition for a mold according to such a configuration, and the resin-coated sand is molded and cured by heating.
  • FIG. 2 is a vertical cross-sectional explanatory view of a sand mold for casting tests for producing castings used for evaluation of mold characteristics in Examples.
  • FIG. 3 is a longitudinal cross-sectional explanatory view of a cast iron casting obtained using the sand mold for casting test shown in FIG. 2 ;
  • the ratio of the total value of the peak area of the phenolic monomer and the peak area of the phenolic dimer to the total area of the peaks in the gel filtration chromatographic measurement as the phenolic resin serving as the caking component. is 13.0% or more as the first essential component. If a phenolic resin with such a ratio is less than 13.0% is used, it becomes difficult to solve the problems of the present invention, that is, problems such as seizure prevention and insertion prevention, and it is difficult to eliminate casting defects. Become.
  • the ratio of the total value can be calculated according to a known area percentage method as an analysis method for gel filtration chromatography measurement.
  • the phenol resin is a solid or liquid (varnish) obtained by reacting phenols and aldehydes in the presence of an acidic catalyst or a basic catalyst. or in the form of an emulsion), which are called novolak-type or resol-type condensation products depending on the type of catalyst used therein, in the presence or absence of a given curing agent or curing catalyst. It expresses thermosetting property by heating in the presence.
  • the phenolic resin produced by the above reaction generally contains unreacted phenolic monomers and phenolic dimers, and those sold as phenolic resins contain such phenolic monomers.
  • the ratio of the total value of the peak area of the phenolic monomer and the peak area of the phenolic dimer to the total area of the peaks in gel filtration chromatograph measurement is 13.0% or more, Either resol type phenolic resin or novolac type phenolic resin can be used.
  • phenols used as raw materials for phenolic resins include phenol and phenol derivatives.
  • aldehydes include formalin, which is an aqueous solution of formaldehyde, paraformaldehyde, trioxane, acetaldehyde, and paraaldehyde. , propionaldehyde, etc., and other known aldehyde compounds can be used as appropriate. Any of the phenols and aldehydes may be used alone, or two or more of them may be used in combination.
  • the novolak-type phenolic resin used in the present invention is prepared by using the above-described phenols and aldehydes, and as is well known, an acid catalyst such as inorganic acids such as hydrochloric acid, sulfuric acid and phosphoric acid, and oxalic acid. , p-toluenesulfonic acid, benzenesulfonic acid, xylenesulfonic acid, etc., and further acidic substances such as zinc oxide, zinc chloride, magnesium oxide, zinc acetate, etc., through a condensation reaction.
  • the blending molar ratio (F/P) of the aldehydes (F) and the phenols (P) can be appropriately selected depending on the type of reaction catalyst used, etc., but is preferably , 0.55 to 0.80.
  • the phenols to be reacted with the aldehydes not only phenol is used, but at least part of the phenol is used as a raw material for modification. It is also possible to use a modified novolac-type phenolic resin obtained by reacting aldehydes with an acidic catalyst by using a material (phenol + modifying raw material) substituted for .
  • phenol derivatives can be used as modifying raw materials to replace phenol, but resorcinol, bisphenol F, Polyhydric phenols such as bisphenol A and purification residues of these bisphenols; polycyclic phenols such as 1-naphthol, 2-naphthol, 1-hydroxyanthracene, and 2-hydroxyanthracene; At least one of alkylphenols is employed.
  • the modification ratio of the modified novolac-type phenolic resin in other words, the substitution ratio of phenol by the raw material for modification is generally 20 to 100% by mass, preferably 25 to 95% by mass, more preferably 30 to 90% by mass.
  • the modification rate of such a modified novolac-type phenolic resin is too low, the decomposition of the resin cannot be sufficiently accelerated, and there is the problem that it becomes difficult to effectively increase the volatilization rate.
  • the modification rate is high, the heat resistance of the resin is lowered, and there is a risk that the generation of gas, etc., will end before the molten metal such as molten cast iron to be cast is solidified. .
  • the resol-type phenolic resin is formed by using the above-mentioned phenols and aldehydes and conducting a condensation reaction with a known basic catalyst in the same manner as in the past.
  • a known basic catalyst hydroxides of alkali metals or alkaline earth metals such as sodium hydroxide and calcium hydroxide, and oxides of alkaline earth metals can be used.
  • the blending molar ratio (F/P) of aldehydes and phenols in such a condensation reaction is appropriately selected according to the type of reaction catalyst used therein, but is generally 1.1. It will be selected within the range of ⁇ 4.0.
  • novolak-type phenolic resins It is possible to produce novolak-type phenolic resins, modified novolak-type phenolic resins, and resol-type phenolic resins according to the above-described reactions.
  • the ratio of the total value of the peak area of the group monomer and the peak area of the phenolic dimer is at least 13.0%. It is possible to manufacture by
  • the phenolic resins used in combination are all peaks of phenolic monomers with respect to the total area of peaks in gel filtration chromatograph measurement It is preferable that the ratio of the total value of the peak area of the area and the phenolic dimer (hereinafter simply referred to as "the ratio of the total value”) is 13.0% or more.
  • the ratio of the total value of the entire phenolic resin constituting the mold resin composition is, more specifically, when two or more phenolic resins are used, the two or more phenolic resins As long as the ratio of the total value of the mixture of is 13.0% or more, it is also possible to use a phenolic resin having a ratio of the total value of less than 13.0%. When two or more phenolic resins are used together, it is particularly preferable to use a modified novolac phenolic resin and a resol phenolic resin together.
  • a cured product of a resin composition containing a modified novolak-type phenolic resin and a resol-type phenolic resin tends to have a relatively low cross-linking density and generate a large amount of gas when heated, and thus more advantageously enjoy the effects of the present invention. It becomes possible to
  • the blending ratio is based on the mass of the modified novolak-type phenol resin: resol-type phenol.
  • a use ratio of resin 10:90 to 95:5, preferably 20:80 to 90:10 will be advantageously employed.
  • the ratio of modified novolac-type phenolic resin used increases (the ratio of resol-type phenolic resin used decreases), the curing speed tends to become slower, and the ratio of modified novolac-type phenolic resin used decreases, so resol-type If the amount of phenol resin increases, problems such as a decrease in mold strength will occur.
  • a carbonization accelerator for promoting carbonization of the heated phenolic resin is used as a second essential component together with the specific phenolic resin described above.
  • a carbonization accelerator for promoting carbonization of the heated phenolic resin is used as a second essential component together with the specific phenolic resin described above.
  • the carbonization of the phenolic resin is effectively promoted, and in particular, after the middle stage of casting (a stage relatively long after the start of pouring), the carbonization of the phenolic resin is formed.
  • a carbonized film is advantageously formed between the mold and the molten metal, thereby effectively protecting the mold from the high-temperature molten metal and effectively suppressing or preventing the occurrence of seizure. Problems such as insertion of molten metal can be prevented, and the casting surface of the obtained casting can be effectively improved.
  • the carbonization accelerator in the present invention is not particularly limited as long as it can promote the carbonization of the phenolic resin when heated together with the phenolic resin.
  • organic phosphates used as carbonization accelerators include halogen-containing phosphates such as tris(tribromopentyl)phosphate and tris( ⁇ -chloropropyl)phosphate (TCPP), and halogen-free Non-halogen phosphates and halogen-free non-halogen condensed phosphates can be exemplified.
  • non-halogenated phosphates include aliphatic phosphates such as trimethyl phosphate, triethyl phosphate, tripropyl phosphate, tributyl phosphate, methyldiethyl phosphate, methyldibutyl phosphate, and ethyl dibutyl phosphate; Phenyl phosphate, tricresyl phosphate, trixylenyl phosphate, cresyl diphenyl phosphate, 2-ethylhexyldiphenyl phosphate, t-butylphenyl diphenyl phosphate, bis-(t-butylphenyl)phenyl phosphate, tris-(t-butylphenyl) Aromatic phosphoric acid esters such as phosphate, isopropylphenyldiphenylphosphate, bis-(isopropylphenyl)diphenylphosphate, tris-(isopropylphen
  • non-halogenated phosphate esters When such non-halogenated phosphate esters are used as the carbonization accelerator of the present invention, those having a phosphorus content of 8% or more calculated by the following formula (1) are advantageously used.
  • [Phosphorus content] (%) [(atomic weight of phosphorus element in compound
  • organic halides used as carbonization accelerators include chlorinated paraffin, chlorinated diphenyl, chlorinated ethane, chlorinated polyethylene, chlorinated polyphenyl, chlorinated diphenyl, vinyl chloride, perchlorocyclopenta Organic chlorine compounds such as decanone, tetrachlorobisphenol A, trischloroethyl phosphate, trisdichloropropyl phosphate, tris- ⁇ -chloropropyl phosphate; brominated paraffin, polybrominated biphenyl (PBB), tetrabromoethane, tetrabromobenzene , decabromodiphenyl oxide, octabromodiphenyl oxide, hexabromocyclododecane, bis(tribromophenoxy)ethane, ethylenebistetrabromophthalimide, hexabromobenzene, polyd
  • the cured product completely cured at 150 ° C. is measured for the amount of gas generated in a reducing atmosphere at 850 ° C., and the measurement of the total amount of gas generated is started.
  • the molding resin composition according to the present invention can be obtained by adjusting the ratio of the amount of gas generated in 20 seconds to 50% or more. In this way, among the amount of gas generated when the cured product is heated in a reducing atmosphere, the amount of gas generated particularly at the initial stage of heating is increased, so that the carbonization accelerator is blended. Therefore, it is possible to enjoy the effects of the present invention.
  • the amount of the carbonization accelerator used is usually about 2 to 50 parts by mass, preferably in the range of 3 to 50 parts by mass, with respect to 100 parts by mass of the phenolic resin. It will happen.
  • the timing of blending the carbonization accelerator in the preparation of the casting resin composition can be appropriately selected based on the knowledge of those skilled in the art.
  • a carbonization accelerator to the phenol resin. It may be blended (mixed) at the time of resin synthesis, or may be mixed with a molten novolak-type phenolic resin immediately after synthesis. It is also possible to add a carbonization accelerator during or after kneading with the resin and mix.
  • the resin composition for molds of the present invention may optionally contain various kinds of compounds that have been generally used in the past for the purpose of improving the physical properties of the mold making material itself and improving the physical properties of the mold to be molded.
  • Additives can also be blended as appropriate.
  • lubricants that contribute to the improvement of fluidity of casting mold materials include waxes such as paraffin wax, synthetic polyethylene wax, and montanic acid wax; stearic acid, stearyl alcohol, stearic acid monoglyceride; stearyl stearate; metal stearates such as calcium stearate, zinc stearate, magnesium stearate and lead stearate; hardened oils and the like can be added.
  • a coupling agent that strengthens the bond between the refractory aggregate and additive components such as binder resin.
  • additive components such as binder resin.
  • silane coupling agents, zircon coupling agents, titanium coupling agents, etc. are used. can do
  • release agents such as paraffin, wax, light oil, machine oil, spindle oil, insulating oil, waste oil, vegetable oil, fatty acid ester, organic acid, mica, vermiculite, fluorine release agent, silicone release agent, etc. is also available.
  • Each of these additives is used in a proportion of about 0.1 to 10 parts by weight, preferably about 0.5 to 5 parts by weight, per 100 parts by weight of the phenolic resin.
  • RCS casting mold material
  • silica sand and artificial silica sand including silica sand and artificial silica sand, special sand such as alumina sand, olivine sand, zircon sand, chromite sand, and slag particles such as ferrochrome slag, ferronickel slag, and converter slag; artificial particles such as alumina-based particles and mullite-based particles, and regenerated particles thereof; alumina balls, magnesia clinker, and the like.
  • These refractory aggregates may be new sand, or recycled or recovered sand that has been used once or more than once for molding molds as foundry sand.
  • refractory aggregates are generally used with a particle size of about 40 to 200, preferably about 60 to 150, in terms of AFS index.
  • a binder resin predetermined Phenolic resin
  • a carbonization accelerator and other additives selected as necessary are added, and after kneading, a predetermined curing agent such as hexamethylenetetramine and a curing accelerator are added, and air cooling Therefore, a so-called dry hot coating method, in which the lump content is broken into granules and then calcium stearate (lubricant) is added, is advantageously employed.
  • the timing of kneading the molding resin composition of the present invention and the refractory aggregate can be appropriately selected based on the knowledge of those skilled in the art.
  • each component constituting the resin composition for casting molds is added to the refractory aggregates.
  • the carbonization accelerator can be mixed with the phenolic resin, or all components can be mixed at the same time.
  • a large amount of additives such as a carbonization accelerator it is possible to adopt a divided addition method such as adding both the phenol resin and the refractory aggregate and phenol resin after kneading. be.
  • the mold-making material obtained as described above is heated to harden by heating.
  • the desired mold is molded, but such a heat molding method is not particularly limited, and any conventionally known method can be advantageously used.
  • the mold-making material as described above is filled into a mold heated to about 150 to 300° C., which has a desired molding space that provides the desired mold, by a gravity drop method, a blow method, or the like, and cured. After that, the desired casting mold can be obtained by removing the hardened mold from the mold.
  • such a casting mold is advantageously molded at a filling rate of 50% or more, and by realizing such a filling rate, the internal structure of the mold takes a stone wall structure. This makes it possible to prevent the intrusion of molten metal and advantageously increase the gas pressure from the mold.
  • a mold filling rate can be measured by a known method, and for example, a method as disclosed in paragraph [0060] of JP-A-2019-177402 can be employed.
  • the mold thus obtained is advantageously endowed with the above-mentioned excellent features such as seizure resistance. It can be advantageously used for casting of iron-based molten metal, and its characteristics can be exhibited more effectively.
  • the ratio (%) of the total value is simply referred to as "area ratio (%)".
  • the area ratios of the phenol resins A to D are shown in Tables 1 to 3 below, respectively.
  • Example 16 Comparative Example 4 and Comparative Example 5 using any two of the phenolic resins A to D, phenol mixed at the ratio shown in Table 2 or Table 3 below Using the resin mixture as a sample, GPC measurement was performed, and the area ratio (%) calculated from the measurement results is shown in Tables 2 and 3 below.
  • the resin compositions for molds according to the following examples and comparative examples were pulverized and mixed as necessary depending on the components, then the resin compositions were placed in an aluminum cup, and the aluminum cup was heated to about 150°C. It is placed on a metal plate, and after the resin composition in the cup is thermally melted, it is cured for 5 minutes while stirring the inside of the cup with a spatula. After that, the aluminum cup is transferred from the metal plate to a thermo-hygrostat heated to 150° C. and placed in the thermo-hygrostat for 30 minutes to completely cure the resin composition in the aluminum cup.
  • a cured product of the obtained resin composition is pulverized, and the pulverized product is put into a copper tube and sealed with glass wool to obtain a sample.
  • the sample is placed in a furnace having a reducing atmosphere at 850° C. in a gas generation amount measuring machine, and the amount of gas generated from the pulverized material is measured immediately after the placement. The measurement is continued until the generation of gas is finished, and from the measurement results, the amount of gas generated in 20 seconds from immediately after placing the sample in the furnace and the total amount of gas generated are calculated. From the calculation result, the ratio (%) of the amount of gas (a) generated within 20 seconds to the total amount of gas generated (A) is calculated.
  • FIG. 1 the measurement results of the amount of gas generated for each mold resin composition according to Example 1 and Comparative Example 1 are shown in FIG. 1 as a graph.
  • a half hollow main mold 6 (cavity diameter: 6 cm, height: 6 cm), a circular airless element having a skirting part 8, which was molded by blowing and filling each mold molding material into a mold heated to 250 ° C. and heating for 120 seconds.
  • 10 (diameter: 5 cm, height: 5 cm) is adhesively fixed by the baseboard fixing part 4, and then the half-split hollow main mold 6 is adhesively fixed to each other to prepare a sand mold 12 for casting test.
  • the bonded main mold is clamped with a vise or the like, or tightly fixed by wrapping it with a wire.
  • molten cast iron FC200 (temperature: 1380° C. ⁇ 40° C.) is poured from the molten metal injection port 2 of the sand mold 12 for casting test and allowed to solidify. 3, a cylindrical casting 16 is removed. Then, the resulting casting 16 is cut in half, and the conditions of seizure and casting surface (casting surface) are visually and tactilely confirmed. evaluate.
  • Phenolic Resin A A reaction vessel equipped with a thermometer, stirrer and condenser was charged with 350 parts phenol, 118 parts 47% formalin, 30 parts 92% paraformaldehyde and 3 parts oxalic acid. Next, the temperature of the reaction vessel was gradually raised while stirring the inside of the vessel until it reached the reflux temperature, and then the reflux reaction was carried out for 90 minutes while maintaining the reflux temperature. 430 parts of phenolic resin A, which is a novolac-type phenolic resin, was obtained by concentrating under reduced pressure while heating until the content reached . The area ratio of the phenolic resin A (in GPC measurement, the ratio of the sum of the peak area of the phenolic monomer and the peak area of the phenolic dimer to the total peak area) was 13.9%.
  • Phenolic Resin B- A reaction vessel equipped with a thermometer, stirrer and condenser was charged with 115 parts phenol, 110 parts 47% formalin, 450 parts bisphenol A, 100 parts water and 2 parts oxalic acid. Next, the temperature of the reaction vessel was gradually raised while stirring the inside of the vessel until it reached the reflux temperature, and then the reflux reaction was carried out for 90 minutes while maintaining the reflux temperature. 600 parts of phenolic resin B, which is a modified novolac-type phenolic resin, was obtained by concentrating under reduced pressure while heating until the content reached 600 parts. The area ratio of the phenolic resin B (in GPC measurement, the ratio of the sum of the peak area of the phenolic monomer and the peak area of the phenolic dimer to the total peak area) was 26.0%.
  • Phenolic Resin D- A reaction vessel equipped with a thermometer, stirrer and condenser was charged with 400 parts phenol, 217 parts 47% formalin, and 3 parts oxalic acid. Next, the temperature of the reaction vessel was gradually raised while stirring the inside of the vessel until it reached the reflux temperature, and then the reflux reaction was carried out for 90 minutes while maintaining the reflux temperature. 570 parts of phenolic resin A, which is a novolac-type phenolic resin, was obtained by concentrating under reduced pressure while heating until the content reached . The area ratio of the phenolic resin D (in GPC measurement, the ratio of the sum of the peak area of the phenolic monomer and the peak area of the phenolic dimer to the total peak area) was 10.6%.
  • Example 1- 100 parts of a phenolic resin A and 10 parts of an aliphatic condensed phosphate: PNX (trade name: Fyrol PNX-LE, manufactured by ICL JAPAN Co., Ltd.) as a carbonization accelerator as components of a resin composition for a mold. and 15 parts of hexamethylenetetramine as a curing agent dissolved in water.
  • PNX trade name: Fyrol PNX-LE, manufactured by ICL JAPAN Co., Ltd.
  • PNX aliphatic condensed phosphate
  • the phenolic resin A of the mold resin composition and the carbonization accelerator (PNX) were sequentially put into a whirl mixer and mixed for 60 seconds. Kneaded. Further, a hardening agent (hexamethylenetetramine) dissolved in water was added, air cooled, and then 5 parts of calcium stearate was added to obtain a mold material for shell mold (molding material).
  • PNX carbonization accelerator
  • Example 2- For shell molds, following the same procedure as in Example 1, except that an aromatic condensed phosphate ester (trade name: CR-733S, Daihachi Chemical Industry Co., Ltd.) was used instead of PNX as the carbonization accelerator. A mold material was obtained.
  • an aromatic condensed phosphate ester trade name: CR-733S, Daihachi Chemical Industry Co., Ltd.
  • Example 3- A mold material for a shell mold was obtained in the same manner as in Example 1, except that 2,4,6-tribromophenol (TBP), which is an organic halide, was used as the carbonization accelerator instead of PNX. rice field.
  • TBP 2,4,6-tribromophenol
  • Example 4- A mold material for a shell mold was obtained in the same manner as in Example 1, except that tetrabromobisphenol A (TBBA), which is an organic halide, was used as the carbonization accelerator instead of PNX.
  • TBBA tetrabromobisphenol A
  • Example 5- A mold material for a shell mold was obtained in the same manner as in Example 1, except that the amount of carbonization accelerator (PNX) used was 3 parts.
  • Example 6- A mold material for shell mold was obtained in the same manner as in Example 1, except that phenol resin B was used instead of phenol resin A.
  • Example 7- A mold material for shell mold was obtained in the same manner as in Example 2, except that phenol resin B was used instead of phenol resin A.
  • Example 8- A mold material for a shell mold was obtained in the same manner as in Example 7, except that the amount of carbonization accelerator (CR-733S) used was 3 parts.
  • Example 9- Instead of 100 parts of phenolic resin A, 75 parts of phenolic resin A and 25 parts of phenolic resin C were used, and the amount of curing agent (hexamethylenetetramine) used was 4 parts. A mold material for a shell mold was obtained in the same manner as in Example 1.
  • Example 10- Instead of 100 parts of phenolic resin A, 75 parts of phenolic resin A and 25 parts of phenolic resin C were used, and the amount of curing agent (hexamethylenetetramine) used was 4 parts.
  • a shell mold material was obtained in the same manner as in Example 2.
  • Example 11- Instead of 100 parts of phenolic resin A, 75 parts of phenolic resin A and 25 parts of phenolic resin C were used, and the amount of curing agent (hexamethylenetetramine) used was 4 parts. A shell mold material was obtained in the same manner as in Example 3.
  • Example 12- Instead of 100 parts of phenolic resin A, 75 parts of phenolic resin A and 25 parts of phenolic resin C were used, and the amount of curing agent (hexamethylenetetramine) used was 4 parts. A shell mold material was obtained in the same manner as in Example 4.
  • Example 13- Instead of 100 parts of phenolic resin A, 75 parts of phenolic resin B and 25 parts of phenolic resin C were used, and the amount of curing agent (hexamethylenetetramine) used was 4 parts.
  • a mold material for a shell mold was obtained in the same manner as in Example 1.
  • Example 14- Instead of 100 parts of phenolic resin A, 75 parts of phenolic resin B and 25 parts of phenolic resin C were used, and the amount of curing agent (hexamethylenetetramine) used was 4 parts.
  • a shell mold material was obtained in the same manner as in Example 2.
  • Example 15- A mold material for shell mold was obtained in the same manner as in Example 1, except that phenolic resin C was used instead of phenolic resin A and the curing agent (hexamethylenetetramine) was not used.
  • Example 16- Instead of 100 parts of phenolic resin A, 25 parts of phenolic resin C and 75 parts of phenolic resin D were used, and the amount of curing agent (hexamethylenetetramine) used was 4 parts.
  • a mold material for a shell mold was obtained in the same manner as in Example 1.
  • Example 1 A mold material for shell mold was obtained in the same manner as in Example 1, except that phenolic resin D was used instead of phenolic resin A.
  • Example 2- A mold material for a shell mold was obtained in the same manner as in Example 1, except that no carbonization accelerator (PNX) was used.
  • PNX carbonization accelerator
  • Example 4 A mold material for a shell mold was obtained in the same manner as in Example 9, except that no carbonization accelerator (TBP) was used.
  • TBP carbonization accelerator
  • Example 5 A mold material for a shell mold was obtained in the same manner as in Example 13, except that no carbonization accelerator (PNX) was used.
  • PNX carbonization accelerator
  • Example 7- A mold material for a shell mold was obtained in the same manner as in Example 1, except that phenolic resin D was used instead of phenolic resin A and no carbonization accelerator (PNX) was used.
  • Example 8 A mold material for a shell mold was obtained in the same manner as in Example 1, except that the amount of carbonization accelerator (PNX) used was 1 part.
  • PNX carbonization accelerator

Abstract

The present invention provides a composition for molds, the composition being capable of advantageously producing a mold that is able to effectively suppress or prevent the occurrence of casting defects due to welding, metal penetration or the like.　A resin composition for molds according to the present invention contains (a) a phenolic resin wherein the ratio of the sum of the peak area of a phenolic monomer and the peak area of a phenolic dimer to the total peak area as determined by gel filtration chromatography is 13.0% or more, and (b) a carbonization accelerator which accelerates carbonization of the phenolic resin; and this resin composition for molds is prepared so that, with respect to the measurement of the gas generation amount in a reducing atmosphere at 850°C of (c) a cured product, which is obtained by completely curing this resin composition for molds at 150°C, the ratio of the gas generation amount for 20 seconds from the beginning of the measurement to the total gas generation amount is 50% or more.

Description

鋳型用樹脂組成物Mold resin composition
　本発明は、鋳型用樹脂組成物に係り、特に、鋳物欠陥の発生を効果的に抑制乃至は阻止せしめ得るシェルモールド鋳型の如き鋳型を製造する際に、有利に用いられる樹脂組成物に関するものである。 TECHNICAL FIELD The present invention relates to a resin composition for casting molds, and more particularly to a resin composition that is advantageously used in the production of casting molds such as shell molds capable of effectively suppressing or preventing the occurrence of casting defects. be.
　従来から、ケイ砂等の耐火性骨材を粘結剤によって結合させて、造型することによって得られるシェルモールド鋳型を用いた鋳造工程においては、金属溶湯の差込みや焼付きによって、鋳肌が悪化する等の鋳物欠陥が惹起されるようになるところから、鋳型表面に、黒鉛、ジルコン、酸化アルミニウム等を含む塗型剤を塗布することが行なわれているが、その塗布作業は、煩雑な作業であると共に、鋳造作業を複雑化せしめ、その作業性を悪化させていることに加えて、鋳造後における鋳型の崩壊性も悪くなる等の問題も、内在するものであった。 Conventionally, in the casting process using a shell mold, which is obtained by binding refractory aggregates such as silica sand with a binder, the casting surface deteriorates due to the insertion and seizure of molten metal. In order to prevent casting defects such as cracking, the surface of the mold is coated with a coating agent containing graphite, zircon, aluminum oxide, etc. However, the coating work is a complicated work. In addition to complicating the casting work and deteriorating the workability, there are inherent problems such as deterioration of the disintegration of the mold after casting.
　このような状況の下、特許文献１（特許第４６５６４７４号公報）においては、耐火骨材の表面に熱硬化性樹脂と炭素質材料とを被覆して調製され、溶湯を流し込んで鋳造を行なう鋳型を造型するためのシェルモールド用レジンコーテッドサンドであって、上記の炭素質材料は固定炭素量が５０～９８質量％であると共に、このレジンコーテッドサンドを用いて造型された鋳型を１０００℃で２４０秒加熱したときのガス発生量が、鋳型１ｃｍ3 当り２０ｍＬ以上であることを特徴とするものが、提案されている。同特許文献においては、かかるレジンコーテッドサンドを用いて造型された鋳型は、塗型剤を用いる必要なく、シェルモールド（鋳型）を溶湯の高温から保護することが出来ると共に、鋳物の鋳肌を向上させることが出来る、とされている。 Under such circumstances, in Patent Document 1 (Patent No. 4656474), a mold is prepared by coating the surface of a refractory aggregate with a thermosetting resin and a carbonaceous material, and casting is performed by pouring molten metal. The carbonaceous material has a fixed carbon content of 50 to 98% by mass, and a mold molded using this resin-coated sand is heated at 1000 ° C. to 240 ° C. It has been proposed that the amount of gas generated when heated for a second is 20 mL or more per 1 cm 3 of the mold. In the same patent document, a mold molded using such a resin-coated sand can protect the shell mold (mold) from the high temperature of the molten metal without using a mold wash agent, and improve the casting surface of the casting. It is said that it is possible to
　しかしながら、そのようなレジンコーテッドサンドを用いて造型して得られるシェルモールド鋳型にあっては、鋳造時に高温の溶湯が注湯されても、鋳型の最終ガス発生量が多く、ガス欠陥が発生する問題を内在していると共に、鋳肌の改善も今一つ充分ではなく、特に、焼付きや差込み等の鋳物欠陥が、充分に改善され得るものではなかった。 However, in a shell mold mold obtained by molding using such a resin-coated sand, even if high-temperature molten metal is poured during casting, the final amount of gas generated in the mold is large, and gas defects occur. In addition to the inherent problems, improvement of the casting surface is not sufficient, and in particular, casting defects such as seizure and insertion cannot be sufficiently improved.
特許第４６５６４７４号公報Japanese Patent No. 4656474
　ここにおいて、本発明は、かかる事情を背景にして為されたものであって、その解決すべき課題とするところは、焼付きや差込み等に係る鋳物欠陥の発生を効果的に抑制乃至は阻止し得る鋳型を、有利に製造することが出来る鋳型用組成物を提供することにある。また、本発明は、塗型剤の塗布を不要として、鋳造作業を効果的に改善し得るシェルモールド鋳型の如き鋳型を、有利に製造することが出来る鋳型用組成物を提供することも、他の解決課題とするところである。 Here, the present invention has been made against the background of such circumstances, and the problem to be solved is to effectively suppress or prevent the occurrence of casting defects such as seizure and insertion. It is an object of the present invention to provide a composition for a casting mold, which can advantageously produce a casting mold that can be used. In addition, the present invention provides a casting composition that can advantageously produce a casting mold such as a shell mold that can effectively improve the casting operation without applying a washing agent. This is a problem to be solved.
　そして、本発明は、上記した課題を解決するために、以下に列挙せる如き各種の態様において、好適に実施され得るものであるが、また、以下に記載の各態様は、任意の組み合わせにおいて、採用可能である。なお、本発明の態様乃至は技術的特徴は、以下に記載のものに何等限定されるものではなく、明細書全体の記載や図面から把握される発明思想に基づいて、認識され得るものであることが、理解されるべきである。 In order to solve the above-described problems, the present invention can be suitably implemented in various aspects as listed below. Adoptable. It should be noted that the aspects and technical features of the present invention are not limited to those described below, and can be recognized based on the inventive idea grasped from the description of the entire specification and the drawings. should be understood.
（１）　ゲル濾過クロマトグラフ測定におけるピークの総面積に対する、フ
　　　ェノール類モノマーのピーク面積及びフェノール類ダイマーのピーク
　　　面積の合計値の割合が１３．０％以上であるフェノール樹脂と、かか
　　　るフェノール樹脂の炭化を促進する炭化促進剤とを含み、
　　　　１５０℃で完全硬化させた硬化物の、８５０℃の還元雰囲気下で発
　　　生するガス量の測定において、発生するガスの総量に対する測定開始
　　　から２０秒間で発生するガス量の割合が５０％以上である、
　　　ことを特徴とする鋳型用樹脂組成物。
（２）　前記フェノール樹脂が、ノボラック型フェノール樹脂、変性ノボラ
　　　ック型フェノール樹脂及びレゾール型フェノール樹脂からなる群より
　　　選ばれる一種以上のものである前記態様（１）に記載の鋳型用樹脂組
　　　成物。
（３）　前記炭化促進剤が、有機リン酸エステル及び／又は有機ハロゲン化
　　　物である前記態様（１）又は前記態様（２）に記載の鋳型用樹脂組成
　　　物。
（４）　鉄系溶湯の鋳造用鋳型の造型に用いられる前記態様（１）乃至前記
　　　態様（３）の何れか１つに記載の鋳型用樹脂組成物。
（５）　前記態様（１）乃至前記態様（４）の何れか１つに記載の鋳型用樹
　　　脂組成物と耐火性骨材とを用いてなるレジンコーテッドサンド。
（６）　前記態様（５）に記載のレジンコーテッドサンドを用いて造型し、
　　　加熱硬化せしめてなる鋳型。 (1) A phenolic resin in which the ratio of the total value of the peak area of phenolic monomers and the peak area of phenolic dimers to the total peak area in gel filtration chromatography measurement is 13.0% or more, and such phenol and a carbonization accelerator that promotes carbonization of the resin,
When measuring the amount of gas generated in a reducing atmosphere at 850°C from a cured product that has been completely cured at 150°C, the ratio of the amount of gas generated within 20 seconds from the start of measurement to the total amount of gas generated must be 50% or more. be,
A casting mold resin composition characterized by:
(2) The mold resin composition according to aspect (1), wherein the phenolic resin is one or more selected from the group consisting of novolac-type phenolic resins, modified novolac-type phenolic resins and resol-type phenolic resins. thing.
(3) The casting mold resin composition according to the aspect (1) or the aspect (2), wherein the carbonization accelerator is an organic phosphoric acid ester and/or an organic halide.
(4) The mold resin composition according to any one of the above aspects (1) to (3), which is used for making a mold for casting molten iron.
(5) A resin-coated sand comprising the casting mold resin composition according to any one of the aspects (1) to (4) and a refractory aggregate.
(6) Molding using the resin-coated sand according to the aspect (5),
A mold made by heating and hardening.
　このように、本発明に従う鋳型用樹脂組成物にあっては、特定のフェノール樹脂と炭化促進剤を含むと共に、１５０℃で完全硬化させた硬化物について、８５０℃の還元雰囲気下で発生するガス量を測定した際に、発生するガスの総量に対する測定開始から２０秒間で発生するガス量の割合が５０％以上となるように調製されて、構成されるものである。このような構成に係る鋳型用樹脂組成物を用いてレジンコーテッドサンド（鋳型造型用材料）を作製し、かかるレジンコーテッドサンドを造型し、加熱硬化せしめて作製された鋳型にあっては、ａ）鋳造の初期段階（鋳型への注湯開始から比較的早い段階）においては、樹脂組成物に含まれる特定のフェノール樹脂より効果的にガスが発生し、その発生したガスが鋳型内部より溶湯表面に向かい、鋳型と溶湯との間にバリア層として機能するガス層が形成されることによって、また、ｂ）鋳造の中期段階以降（注湯開始から比較的時間が経過した段階）においては、炭化促進剤によって効果的に生成されたフェノール樹脂の炭化物からなる炭化膜が、鋳型と溶湯の間に有利に形成されることによって、鋳型が高温の溶湯から効果的に保護されるようになると共に、焼付きの発生が効果的に抑制乃至は阻止され、更に、溶湯の差込み等の問題の発生を防止して、得られる鋳物の鋳肌が効果的に向上せしめられ得ることとなるのである。そして、このような特徴は、鉄系溶湯の鋳造に用いられる鋳型において、特に有利に発揮され得るのである。 As described above, in the mold resin composition according to the present invention, the cured product containing a specific phenolic resin and a carbonization accelerator and completely cured at 150°C generates gas in a reducing atmosphere at 850°C. It is prepared and configured so that the ratio of the amount of gas generated in 20 seconds from the start of measurement to the total amount of gas generated is 50% or more when the amount is measured. A resin-coated sand (mold-making material) is produced using the resin composition for a mold according to such a configuration, and the resin-coated sand is molded and cured by heating. At the initial stage of casting (relatively early from the start of pouring into the mold), gas is effectively generated from the specific phenolic resin contained in the resin composition, and the generated gas flows from the inside of the mold to the surface of the molten metal. On the other hand, a gas layer that functions as a barrier layer is formed between the mold and the molten metal, and b) after the middle stage of casting (a stage relatively long after the start of pouring), carbonization is promoted. A carbonized film composed of phenolic resin carbide effectively generated by the agent is advantageously formed between the mold and the molten metal, thereby effectively protecting the mold from the high-temperature molten metal and preventing sintering. The occurrence of sticking can be effectively suppressed or prevented, and problems such as penetration of molten metal can be prevented, thereby effectively improving the casting surface of the resulting casting. Such characteristics can be exhibited particularly advantageously in molds used for casting molten iron.
実施例におけるガス発生量の測定結果の一部を示すグラフである。It is a graph which shows a part of measurement result of the gas generation amount in an Example. 実施例における鋳型特性の評価に用いられる鋳物を製造するための鋳造試験用砂型の縦断面説明図である。FIG. 2 is a vertical cross-sectional explanatory view of a sand mold for casting tests for producing castings used for evaluation of mold characteristics in Examples. 図２に示される鋳造試験用砂型を用いて得られた、鋳鉄鋳物の縦断面説明図である。FIG. 3 is a longitudinal cross-sectional explanatory view of a cast iron casting obtained using the sand mold for casting test shown in FIG. 2 ;
　先ず、本発明に従う鋳型用樹脂組成物は、粘結成分たるフェノール樹脂として、ゲル濾過クロマトグラフ測定におけるピークの総面積に対する、フェノール類モノマーのピーク面積及びフェノール類ダイマーのピーク面積の合計値の割合が、１３．０％以上であるものを、第一の必須成分とするものである。かかる割合が１３．０％未満のフェノール樹脂を使用すると、本発明の課題、即ち、焼付き防止や差込みの阻止等の問題の解決が困難となって、鋳物欠陥の解消を図ることが困難となる。なお、上記合計値の割合は、ゲル濾過クロマトグラフ測定の分析法として公知の面積百分率法に倣って、算出することが可能である。 First, in the casting resin composition according to the present invention, the ratio of the total value of the peak area of the phenolic monomer and the peak area of the phenolic dimer to the total area of the peaks in the gel filtration chromatographic measurement as the phenolic resin serving as the caking component. is 13.0% or more as the first essential component. If a phenolic resin with such a ratio is less than 13.0% is used, it becomes difficult to solve the problems of the present invention, that is, problems such as seizure prevention and insertion prevention, and it is difficult to eliminate casting defects. Become. In addition, the ratio of the total value can be calculated according to a known area percentage method as an analysis method for gel filtration chromatography measurement.
　ここで、フェノール樹脂は、よく知られているように、フェノール類とアルデヒド類とを酸性触媒又は塩基性触媒の存在下において反応させることにより得られる、固体状乃至は液体状（ワニス形態のものやエマルジョン形態のものを含む）の縮合生成物であって、そこで用いられる触媒の種類によって、ノボラック型又はレゾール型と称されるものであり、所定の硬化剤乃至は硬化触媒の存在下又は非存在下において加熱することにより、熱硬化性を発現するものである。上記した反応によって生成するフェノール樹脂には、未反応のフェノール類モノマーやフェノール類ダイマーが含まれることが一般的であり、また、フェノール樹脂として販売されているものは、かかるフェノール類モノマー等を含有するものが一般的であり、そして、そのようなフェノール樹脂の購入者（需要者）は、入手したフェノール樹脂をそのまま用いて、鋳型用樹脂組成物を調製し、レジンコーテッドサンド等の鋳型材料を作製することが一般的である。本発明者は、本発明の課題を解決すべく、鋳型用樹脂組成物を構成するフェノール樹脂について鋭意、検討したところ、フェノール樹脂に含まれるフェノール類モノマー及びフェノール類ダイマーの含有量が、最終的に得られる鋳型における焼付きや差込みに大きな影響を与えることを見出し、本発明を完成するに至ったのである。 Here, as is well known, the phenol resin is a solid or liquid (varnish) obtained by reacting phenols and aldehydes in the presence of an acidic catalyst or a basic catalyst. or in the form of an emulsion), which are called novolak-type or resol-type condensation products depending on the type of catalyst used therein, in the presence or absence of a given curing agent or curing catalyst. It expresses thermosetting property by heating in the presence. The phenolic resin produced by the above reaction generally contains unreacted phenolic monomers and phenolic dimers, and those sold as phenolic resins contain such phenolic monomers. Purchasers (users) of such phenolic resins use the obtained phenolic resin as it is to prepare a resin composition for a mold, and use it as a mold material such as resin-coated sand. It is common to fabricate In order to solve the problems of the present invention, the present inventors have made intensive studies on the phenolic resin that constitutes the resin composition for molds. The inventors have found that this has a great influence on the seizure and insertion in the mold obtained in 1, and have completed the present invention.
　本発明においては、ゲル濾過クロマトグラフ測定におけるピークの総面積に対する、フェノール類モノマーのピーク面積及びフェノール類ダイマーのピーク面積の合計値の割合が、１３．０％以上であるフェノール樹脂であれば、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の如何を問わず、何れも使用することが可能である。 In the present invention, if the ratio of the total value of the peak area of the phenolic monomer and the peak area of the phenolic dimer to the total area of the peaks in gel filtration chromatograph measurement is 13.0% or more, Either resol type phenolic resin or novolac type phenolic resin can be used.
　フェノール樹脂の原料として用いられるフェノール類としては、フェノールやフェノールの誘導体を挙げることが出来、また、アルデヒド類としては、ホルムアルデヒドの水溶液の形態であるホルマリンの他、パラホルムアルデヒド、トリオキサン、アセトアルデヒド、パラアルデヒド、プロピオンアルデヒド等を挙げることが出来、更にそれら以外の公知のアルデヒド化合物も、適宜に用いることが出来る。なお、フェノール類及びアルデヒド類の何れも、単独で用いられても、２種以上を組み合わせて用いられても、何等差し支えない。 Examples of phenols used as raw materials for phenolic resins include phenol and phenol derivatives. Examples of aldehydes include formalin, which is an aqueous solution of formaldehyde, paraformaldehyde, trioxane, acetaldehyde, and paraaldehyde. , propionaldehyde, etc., and other known aldehyde compounds can be used as appropriate. Any of the phenols and aldehydes may be used alone, or two or more of them may be used in combination.
　本発明において用いられるノボラック型フェノール樹脂は、上記したフェノール類とアルデヒド類とを用いて、よく知られているように、酸性触媒、例えば、塩酸、硫酸、リン酸等の無機酸や、シュウ酸、パラトルエンスルホン酸、ベンゼンスルホン酸、キシレンスルホン酸等の有機酸、更には、酸化亜鉛、塩化亜鉛、酸化マグネシウム、酢酸亜鉛等の酸性物質にて縮合反応させて、形成されるものである。なお、その際、アルデヒド類（Ｆ）とフェノール類（Ｐ）の配合モル比（Ｆ／Ｐ）としては、用いられる反応触媒の種類等に応じて、適宜に選定され得るところであるが、好ましくは、０．５５～０．８０の範囲内において選定されることとなる。 The novolak-type phenolic resin used in the present invention is prepared by using the above-described phenols and aldehydes, and as is well known, an acid catalyst such as inorganic acids such as hydrochloric acid, sulfuric acid and phosphoric acid, and oxalic acid. , p-toluenesulfonic acid, benzenesulfonic acid, xylenesulfonic acid, etc., and further acidic substances such as zinc oxide, zinc chloride, magnesium oxide, zinc acetate, etc., through a condensation reaction. In this case, the blending molar ratio (F/P) of the aldehydes (F) and the phenols (P) can be appropriately selected depending on the type of reaction catalyst used, etc., but is preferably , 0.55 to 0.80.
　本発明においては、上述したノボラック型フェノール樹脂の範疇に含まれるものであって、アルデヒド類と反応せしめられるフェノール類として、フェノールのみを用いるものではなく、フェノールの少なくとも一部を他の変性用原料に置き換えてなるもの（フェノール＋変性用原料）を用いて、酸性触媒にてアルデヒド類と反応せしめて得られる変性ノボラック型フェノール樹脂を用いることも可能である。 In the present invention, which is included in the category of the novolak-type phenolic resins described above, as the phenols to be reacted with the aldehydes, not only phenol is used, but at least part of the phenol is used as a raw material for modification. It is also possible to use a modified novolac-type phenolic resin obtained by reacting aldehydes with an acidic catalyst by using a material (phenol + modifying raw material) substituted for .
　なお、そのような変性ノボラック型フェノール樹脂を得るために、フェノールに代替される変性用原料としては、公知の各種のフェノール誘導体を用いることが可能であるが、有利には、レゾルシノール、ビスフェノールＦ、ビスフェノールＡ、それらビスフェノールの精製残渣等の多価フェノール；１－ナフトール、２－ナフトール、１－ヒドロキシアントラセン、２－ヒドロキシアントラセン等の多環フェノール；クレゾール、キシレノール，ｐ－ｔｅｒｔ－ブチルフェノール、ノニルフェノール等のアルキルフェノールのうちの少なくとも何れか１つが、採用される。このような変性用原料を用いてフェノール樹脂を変性することにより、フェノール樹脂骨格中に隙間を形成して、その分解が促進されるようになり、以てガス量を増大させ得るものと考えられている。 In order to obtain such a modified novolak-type phenolic resin, various known phenol derivatives can be used as modifying raw materials to replace phenol, but resorcinol, bisphenol F, Polyhydric phenols such as bisphenol A and purification residues of these bisphenols; polycyclic phenols such as 1-naphthol, 2-naphthol, 1-hydroxyanthracene, and 2-hydroxyanthracene; At least one of alkylphenols is employed. By modifying the phenolic resin with such a modifying raw material, it is believed that gaps are formed in the phenolic resin skeleton and the decomposition thereof is accelerated, thereby increasing the amount of gas. ing.
　また、かかる変性ノボラック型フェノール樹脂の変性率、換言すれば変性用原料によるフェノールの代替割合としては、一般に、２０～１００質量％、好ましくは２５～９５質量％、より好ましくは３０～９０質量％が、有利に採用されることとなる。このような変性ノボラック型フェノール樹脂の変性率において、その値が低くなり過ぎると、樹脂の分解を充分に促進せしめ得ず、そのために、揮発率を効果的に高めることが困難となる問題があり、また、かかる変性率が高い場合にあっては、樹脂の耐熱性が低下して、鋳造される鋳鉄溶湯等の金属溶湯の凝固に先立って、ガス等の発生が終了してしまう恐れがある。 In addition, the modification ratio of the modified novolac-type phenolic resin, in other words, the substitution ratio of phenol by the raw material for modification is generally 20 to 100% by mass, preferably 25 to 95% by mass, more preferably 30 to 90% by mass. will be advantageously adopted. If the modification rate of such a modified novolac-type phenolic resin is too low, the decomposition of the resin cannot be sufficiently accelerated, and there is the problem that it becomes difficult to effectively increase the volatilization rate. In addition, when the modification rate is high, the heat resistance of the resin is lowered, and there is a risk that the generation of gas, etc., will end before the molten metal such as molten cast iron to be cast is solidified. .
　一方、レゾール型フェノール樹脂は、上記のフェノール類とアルデヒド類とを用いて、従来と同様にして、公知の塩基性触媒にて縮合反応せしめることにより、形成されることとなる。なお、塩基性触媒としては、水酸化ナトリウムや水酸化カルシウム等のアルカリ金属又はアルカリ土類金属の水酸化物や、アルカリ土類金属の酸化物を用いることが出来る他、ジメチルアミン、トリエチルアミン、ブチルアミン、ジメチルベンジルアミン、ナフタレンジアミン等のアミン類、アンモニア、ヘキサメチレンテトラミンや、その他２価金属のナフテン酸塩や２価金属の水酸化物等を、用いることが出来る。また、そのような縮合反応におけるアルデヒド類とフェノール類の配合モル比（Ｆ／Ｐ）は、そこで用いられる反応触媒の種類等に応じて、適宜に選定されるところであるが、一般に、１．１～４．０の範囲内において選定されることとなる。 On the other hand, the resol-type phenolic resin is formed by using the above-mentioned phenols and aldehydes and conducting a condensation reaction with a known basic catalyst in the same manner as in the past. As the basic catalyst, hydroxides of alkali metals or alkaline earth metals such as sodium hydroxide and calcium hydroxide, and oxides of alkaline earth metals can be used. , dimethylbenzylamine, amines such as naphthalenediamine, ammonia, hexamethylenetetramine, and other divalent metal naphthenates and divalent metal hydroxides. In addition, the blending molar ratio (F/P) of aldehydes and phenols in such a condensation reaction is appropriately selected according to the type of reaction catalyst used therein, but is generally 1.1. It will be selected within the range of ~4.0.
　上述した反応に従い、ノボラック型フェノール樹脂、変性ノボラック型フェノール樹脂及びレゾール型フェノール樹脂を製造することが可能であるが、本発明において使用される「ゲル濾過クロマトグラフ測定におけるピークの総面積に対する、フェノール類モノマーのピーク面積及びフェノール類ダイマーのピーク面積の合計値の割合が、１３．０％以上である」フェノール樹脂は、例えばフェノール類の使用量を変化させる等、反応条件を適宜、選択することにより、製造することが可能である。 It is possible to produce novolak-type phenolic resins, modified novolak-type phenolic resins, and resol-type phenolic resins according to the above-described reactions. The ratio of the total value of the peak area of the group monomer and the peak area of the phenolic dimer is at least 13.0%. It is possible to manufacture by
　また、本発明においては、二種以上のフェノール樹脂を併用することも可能であるが、併用されるフェノール樹脂は、何れも、ゲル濾過クロマトグラフ測定におけるピークの総面積に対する、フェノール類モノマーのピーク面積及びフェノール類ダイマーのピーク面積の合計値の割合（以下、本段落においては、単に「合計値の割合」という）が、１３．０％以上であることを満たすものであることが好ましい。尤も、本発明においては、鋳型用樹脂組成物を構成するフェノール樹脂全体の合計値の割合が、より具体的に、二種以上のフェノール樹脂を使用する場合には、それら二種以上のフェノール樹脂の混合物の合計値の割合が、１３．０％以上であることを満たす限り、合計値の割合が１３．０％未満のフェノール樹脂を用いることも可能である。また、二種以上のフェノール樹脂を併用する場合、変性ノボラック型フェノール樹脂とレゾール型フェノール樹脂とを併用することが、特に好ましい。変性ノボラック型フェノール樹脂及びレゾール型フェノール樹脂を含む樹脂組成物の硬化物は、架橋密度が比較的低くなり、加熱時のガス発生量が多くなる傾向にあり、本発明の効果をより有利に享受することが可能となる。 In addition, in the present invention, it is possible to use two or more phenolic resins in combination, but the phenolic resins used in combination are all peaks of phenolic monomers with respect to the total area of peaks in gel filtration chromatograph measurement It is preferable that the ratio of the total value of the peak area of the area and the phenolic dimer (hereinafter simply referred to as "the ratio of the total value") is 13.0% or more. However, in the present invention, the ratio of the total value of the entire phenolic resin constituting the mold resin composition is, more specifically, when two or more phenolic resins are used, the two or more phenolic resins As long as the ratio of the total value of the mixture of is 13.0% or more, it is also possible to use a phenolic resin having a ratio of the total value of less than 13.0%. When two or more phenolic resins are used together, it is particularly preferable to use a modified novolac phenolic resin and a resol phenolic resin together. A cured product of a resin composition containing a modified novolak-type phenolic resin and a resol-type phenolic resin tends to have a relatively low cross-linking density and generate a large amount of gas when heated, and thus more advantageously enjoy the effects of the present invention. It becomes possible to
　なお、本発明に従う鋳型用樹脂組成物において、変性ノボラック型フェノール樹脂とレゾール型フェノール樹脂とを組み合わせて使用する場合、その配合比率としては、質量基準にて、変性ノボラック型フェノール樹脂：レゾール型フェノール樹脂＝１０：９０～９５：５、好ましくは２０：８０～９０：１０なる使用比率が、有利に採用されることとなる。変性ノボラック型フェノール樹脂の使用比率が高くなる（レゾール型フェノール樹脂の使用比率が低くなる）と、硬化速度が遅くなる傾向があり、また、変性ノボラック型フェノール樹脂の使用割合が少なく、従ってレゾール型フェノール樹脂が多くなると、鋳型強度が低下する等の問題が惹起されることとなる。 In the casting resin composition according to the present invention, when the modified novolak-type phenol resin and the resol-type phenol resin are used in combination, the blending ratio is based on the mass of the modified novolak-type phenol resin: resol-type phenol. A use ratio of resin=10:90 to 95:5, preferably 20:80 to 90:10 will be advantageously employed. When the ratio of modified novolac-type phenolic resin used increases (the ratio of resol-type phenolic resin used decreases), the curing speed tends to become slower, and the ratio of modified novolac-type phenolic resin used decreases, so resol-type If the amount of phenol resin increases, problems such as a decrease in mold strength will occur.
　一方、本発明の鋳型用樹脂組成物にあっては、上述した特定のフェノール樹脂と共に、加熱されたフェノール樹脂の炭化を促進するための炭化促進剤が、第二の必須成分として使用される。このような炭化促進剤を配合することにより、フェノール樹脂の炭化が効果的に促進し、特に鋳造の中期段階以降（注湯開始から比較的時間が経過した段階）に、フェノール樹脂の炭化物からなる炭化膜が鋳型と溶湯の間に有利に形成されることとなり、以て、鋳型が高温の溶湯から効果的に保護されると共に、焼付きの発生が効果的に抑制乃至は阻止され、更に、溶湯の差込み等の問題の発生を防止して、得られる鋳物の鋳肌が効果的に向上せしめられ得ることとなるのである。本発明における炭化促進剤としては、フェノール樹脂と共に加熱された際に、フェノール樹脂の炭化を促進することが可能なものであれば、特に限定されることなく、使用可能であるが、好ましくは、有機リン酸エステル及び／又は有機ハロゲン化物を挙げることが出来る。 On the other hand, in the casting resin composition of the present invention, a carbonization accelerator for promoting carbonization of the heated phenolic resin is used as a second essential component together with the specific phenolic resin described above. By blending such a carbonization accelerator, the carbonization of the phenolic resin is effectively promoted, and in particular, after the middle stage of casting (a stage relatively long after the start of pouring), the carbonization of the phenolic resin is formed. A carbonized film is advantageously formed between the mold and the molten metal, thereby effectively protecting the mold from the high-temperature molten metal and effectively suppressing or preventing the occurrence of seizure. Problems such as insertion of molten metal can be prevented, and the casting surface of the obtained casting can be effectively improved. The carbonization accelerator in the present invention is not particularly limited as long as it can promote the carbonization of the phenolic resin when heated together with the phenolic resin. Organic phosphates and/or organic halides may be mentioned.
　具体的に、炭化促進剤として用いられる有機リン酸エステルとしては、トリス（トリブロモペンチル）ホスフェートやトリス（β－クロロプロピル）ホスフェート（ＴＣＰＰ）等のハロゲン含有リン酸エステル類や、ハロゲン不含の非ハロゲン系リン酸エステル類、ハロゲン不含の非ハロゲン系縮合リン酸エステル類を、例示することが出来る。より具体的に、非ハロゲン系リン酸エステル類としては、トリメチルホスフェート、トリエチルホスフェート、トリプロピルホスフェート、トリブチルホスフェート、メチルジエチルホスフェート、メチルジブチルホスフェート、エチルジブチルホスフェート等の脂肪族リン酸エステル類や、トリフェニルホスフェート、トリクレジルホスフェート、トリキシレニルホスフェート、クレジルジフェニルホスフェート、２－エチルヘキシルジフェニルホスフェート、ｔ－ブチルフェニルジフェニルホスフェート、ビス－（ｔ－ブチルフェニル）フェニルホスフェート、トリス－（ｔ－ブチルフェニル）ホスフェート、イソプロピルフェニルジフェニルホスフェート、ビス－（イソプロピルフェニル）ジフェニルホスフェート、トリス－（イソプロピルフェニル）ホスフェート等の芳香族リン酸エステル類を、挙げることが出来る。そのような非ハロゲン系リン酸エステル類を本発明の炭化促進剤として使用する場合、下記式（１）にて算出されるリン含有量が８％以上のものが有利に用いられる。また、非ハロゲン系縮合リン酸エステル類としては、オリゴマーエチルエチレンホスフェート、変性オリゴマーエチルエチレンホスフェートやフェニレンビス（フェニルクレゾールホスフェート）、２，２－ビス｛４－［ビス（（モノ又はジ）メチルフェノキシ）ホスホリルオキシ］フェニル｝プロパン、１，３－フェニレンビス（ジキシレニル）ホスフェート、α－ジフェノキシホスホリル－ω－フェノキシポリ（ｎ＝１～３）［オキシ－１，４－フェニレンイソプロピリデン－１，４－フェニレンオキシ（フェノキシホスホリル）］等を、例示することが出来る。
　［リン含有量］（％）
　　　＝［（化合物中のリン元素の原子量×リン元素の個数）
　　　　　／（化合物の分子量）］×１００　・・・（１） Specifically, organic phosphates used as carbonization accelerators include halogen-containing phosphates such as tris(tribromopentyl)phosphate and tris(β-chloropropyl)phosphate (TCPP), and halogen-free Non-halogen phosphates and halogen-free non-halogen condensed phosphates can be exemplified. More specifically, non-halogenated phosphates include aliphatic phosphates such as trimethyl phosphate, triethyl phosphate, tripropyl phosphate, tributyl phosphate, methyldiethyl phosphate, methyldibutyl phosphate, and ethyl dibutyl phosphate; Phenyl phosphate, tricresyl phosphate, trixylenyl phosphate, cresyl diphenyl phosphate, 2-ethylhexyldiphenyl phosphate, t-butylphenyl diphenyl phosphate, bis-(t-butylphenyl)phenyl phosphate, tris-(t-butylphenyl) Aromatic phosphoric acid esters such as phosphate, isopropylphenyldiphenylphosphate, bis-(isopropylphenyl)diphenylphosphate, tris-(isopropylphenyl)phosphate can be mentioned. When such non-halogenated phosphate esters are used as the carbonization accelerator of the present invention, those having a phosphorus content of 8% or more calculated by the following formula (1) are advantageously used. Examples of non-halogen condensed phosphates include oligomeric ethylethylene phosphate, modified oligomeric ethylethylene phosphate, phenylene bis(phenylcresol phosphate), 2,2-bis{4-[bis((mono or di)methylphenoxy ) phosphoryloxy]phenyl}propane, 1,3-phenylenebis(dixylenyl)phosphate, α-diphenoxyphosphoryl-ω-phenoxypoly(n=1-3)[oxy-1,4-phenyleneisopropylidene-1,4 -phenyleneoxy (phenoxyphosphoryl)] and the like can be exemplified.
[Phosphorus content] (%)
= [(atomic weight of phosphorus element in compound x number of phosphorus elements)
/(molecular weight of compound)]×100 (1)
　一方、本発明において、炭化促進剤として用いられる有機ハロゲン化物としては、塩素化パラフィン、塩素化ジフェニル、塩素化エタン、塩素化ポリエチレン、塩素化ポリフェニル、塩素化ジフェニル、塩化ビニル、パークロロシクロペンタデカノン、テトラクロロビスフェノールＡ、トリスクロロエチルホスフェート、トリスジクロロプロピルホスフェート、トリス－β－クロロプロピルホスフェート等の有機塩素化合物；臭素化パラフィン、ポリ臭化ビフェニル（ＰＢＢ）、テトラブロモエタン、テトラブロモベンゼン、デカブロモジフェニルオキサイド、オクタブロモジフェニルオキサイド、ヘキサブロモシクロドデカン、ビス（トリブロモフェノキシ）エタン、エチレンビステトラブロモフタルイミド、ヘキサブロモベンゼン、ポリジブロモフェニレンオキサイド、２，４，６－トリブロモフェノール（ＴＢＰ）、テトラブロモビスフェノールＡ（ＴＢＢＡ）、トリス（２，３－ジブロモプロピル－１）イソシアヌレート、トリブロモフェノールアリルエーテル、臭素化ポリスチレン、トリブロモネオペンチルアルコール、ジブロムジクロルプロパン、ジブロムテトラフルオロエタン、トリス（トリブロモフェニル）ホスフェート、トリス（トリブロモネオペンチル）ホスフェート、ＴＢＢＡ・カーボネートオリゴマー等の有機臭素化合物；ポリテトラフルオロエチレン、パーフルオロアルコキシアルカン、パーフルオロエチレンプロペンコポリマー、エチレンテトラフルオロエチレンコポリマー、エチレンクロロトリフルオロエチレンコポリマー、ポリビニリデンフルオライド、ポリクロロトリフルオロエチレン等の有機フッ素化合物を、例示することが出来る。 On the other hand, in the present invention, organic halides used as carbonization accelerators include chlorinated paraffin, chlorinated diphenyl, chlorinated ethane, chlorinated polyethylene, chlorinated polyphenyl, chlorinated diphenyl, vinyl chloride, perchlorocyclopenta Organic chlorine compounds such as decanone, tetrachlorobisphenol A, trischloroethyl phosphate, trisdichloropropyl phosphate, tris-β-chloropropyl phosphate; brominated paraffin, polybrominated biphenyl (PBB), tetrabromoethane, tetrabromobenzene , decabromodiphenyl oxide, octabromodiphenyl oxide, hexabromocyclododecane, bis(tribromophenoxy)ethane, ethylenebistetrabromophthalimide, hexabromobenzene, polydibromophenylene oxide, 2,4,6-tribromophenol (TBP ), tetrabromobisphenol A (TBBA), tris(2,3-dibromopropyl-1) isocyanurate, tribromophenol allyl ether, brominated polystyrene, tribromoneopentyl alcohol, dibromodichloropropane, dibromtetrafluoro Organic bromine compounds such as ethane, tris(tribromophenyl)phosphate, tris(tribromoneopentyl)phosphate, TBBA/carbonate oligomer; polytetrafluoroethylene, perfluoroalkoxyalkane, perfluoroethylenepropene copolymer, ethylenetetrafluoroethylene copolymer , ethylene chlorotrifluoroethylene copolymer, polyvinylidene fluoride, polychlorotrifluoroethylene, and other organic fluorine compounds can be exemplified.
　そして、上述した特定のフェノール樹脂及び炭化促進剤を用いて、１５０℃で完全硬化させた硬化物の、８５０℃の還元雰囲気下で発生するガス量の測定において、発生するガスの総量に対する測定開始から２０秒間で発生するガス量の割合が５０％以上となるように調製されて、本発明に従う鋳型用樹脂組成物が得られるのである。このように、硬化物を還元雰囲気下で加熱した際のガス発生量のうち、特に加熱初期に発生するガス量が多くなるように構成することによって、炭化促進剤を配合せしめていることと相俟って、本発明の効果を享受することが可能ならしめられるのである。 Then, using the above-mentioned specific phenolic resin and carbonization accelerator, the cured product completely cured at 150 ° C. is measured for the amount of gas generated in a reducing atmosphere at 850 ° C., and the measurement of the total amount of gas generated is started. The molding resin composition according to the present invention can be obtained by adjusting the ratio of the amount of gas generated in 20 seconds to 50% or more. In this way, among the amount of gas generated when the cured product is heated in a reducing atmosphere, the amount of gas generated particularly at the initial stage of heating is increased, so that the carbonization accelerator is blended. Therefore, it is possible to enjoy the effects of the present invention.
　本発明の樹脂組成物の硬化物について、そのガス発生量が上記条件を満たすようにするためには、フェノール樹脂及び炭化促進剤の種類に応じて、それらの配合割合を適宜、設定する必要があるが、一般に、フェノール樹脂に対する炭化促進剤の配合割合が少なすぎると、本発明の効果を享受することが出来ない恐れがある。このため、炭化促進剤の使用量（配合量）は、フェノール樹脂の１００質量部に対して、通常２～５０質量部程度、好ましくは３～５０質量部の範囲内において、適宜に設定されることとなる。なお、鋳型用樹脂組成物の調製に際して炭化促進剤を配合するタイミングは、当業者の知識に基づいて適宜に選定され得るところであり、各成分を単独で順次、配合せしめることの他、各成分を適宜に組み合わせて、配合することも可能である。特に、炭化促進剤をフェノール樹脂に対して配合することも可能であり、炭化促進剤が熱や化学反応による変化等によりその効果を失わない限りにおいては、フェノール樹脂の合成時に、とりわけノボラック型フェノール樹脂の合成時に、配合（混合）しても良く、また合成直後の、溶融状態にあるノボラック型フェノール樹脂に対して混合せしめても良く、更には、鋳型材料作製時における耐火性骨材とフェノール樹脂との混練の途中又はその後に、炭化促進剤を添加して、混合せしめることも可能である。 For the cured product of the resin composition of the present invention, in order for the amount of gas generated to satisfy the above conditions, it is necessary to appropriately set the blending ratios of the phenolic resin and the carbonization accelerator according to the types thereof. However, in general, if the blending ratio of the carbonization accelerator to the phenolic resin is too small, the effect of the present invention may not be obtained. For this reason, the amount of the carbonization accelerator used (mixed amount) is usually about 2 to 50 parts by mass, preferably in the range of 3 to 50 parts by mass, with respect to 100 parts by mass of the phenolic resin. It will happen. The timing of blending the carbonization accelerator in the preparation of the casting resin composition can be appropriately selected based on the knowledge of those skilled in the art. It is also possible to combine them appropriately and mix them. In particular, it is possible to add a carbonization accelerator to the phenol resin. It may be blended (mixed) at the time of resin synthesis, or may be mixed with a molten novolak-type phenolic resin immediately after synthesis. It is also possible to add a carbonization accelerator during or after kneading with the resin and mix.
　また、本発明の鋳型用樹脂組成物には、その硬化を図るべく、必要に応じて、従来から公知のヘキサメチレンテトラミン等の硬化剤や、公知の各種の硬化促進剤、例えば、有機カルボン酸や塩基材料等が添加されることとなる。また、変性ノボラック型フェノール樹脂とレゾール型フェノール樹脂とを併用する場合においては、特開２０１３－１５８８１０号公報やＷＯ２０１３／１１８５７２等に明らかにされている如き、アレニウス塩基、ブレンステッド塩基、ルイス塩基のうちの少なくとも１つが、硬化促進剤として有利に用いられることとなる。 In order to cure the resin composition for molds of the present invention, if necessary, conventionally known curing agents such as hexamethylenetetramine and various known curing accelerators such as organic carboxylic acid or a basic material is added. Further, when a modified novolac-type phenolic resin and a resole-type phenolic resin are used in combination, as disclosed in JP-A-2013-158810 and WO2013/118572, Arrhenius bases, Bronsted bases, and Lewis bases. At least one of them will be advantageously used as a curing accelerator.
　さらに、本発明の鋳型用樹脂組成物には、必要に応じて、鋳型造型用材料自体の物性改善や造型される鋳型の物性改善等を目的として、従来より一般的に用いられている各種の添加剤も、適宜に配合せしめることが可能である。例えば、鋳型造型用材料（レジンコーテッドサンド：ＲＣＳ）の流動性の向上等に寄与する滑剤として、パラフィンワックス、合成ポリエチレンワックス、モンタン酸ワックス等のワックス類；ステアリン酸、ステアリルアルコール、ステアリン酸モノグリセリド、ステアリルステアレート；ステアリン酸カルシウム、ステアリン酸亜鉛、ステアリン酸マグネシウム、ステアリン酸鉛等のステアリン酸金属塩；硬化油等を添加することが可能である。また、耐火性骨材とバインダ樹脂等の添加成分との結合を強化するカップリング剤を含有せしめることも有効であり、例えば、シランカップリング剤、ジルコンカップリング剤、チタンカップリング剤等を用いることが出来る。加えて、離型剤として、パラフィン、ワックス、軽油、マシン油、スピンドル油、絶縁油、廃油、植物油、脂肪酸エステル、有機酸、雲母、蛭石、フッ素系離型剤、シリコーン系離型剤等も使用可能である。そして、それらの添加剤は、それぞれ、フェノール樹脂の１００質量部に対して、０．１～１０質量部程度、好ましくは０．５～５質量部程度の割合において、用いられることとなる。 Furthermore, the resin composition for molds of the present invention may optionally contain various kinds of compounds that have been generally used in the past for the purpose of improving the physical properties of the mold making material itself and improving the physical properties of the mold to be molded. Additives can also be blended as appropriate. For example, lubricants that contribute to the improvement of fluidity of casting mold materials (resin coated sand: RCS) include waxes such as paraffin wax, synthetic polyethylene wax, and montanic acid wax; stearic acid, stearyl alcohol, stearic acid monoglyceride; stearyl stearate; metal stearates such as calcium stearate, zinc stearate, magnesium stearate and lead stearate; hardened oils and the like can be added. It is also effective to incorporate a coupling agent that strengthens the bond between the refractory aggregate and additive components such as binder resin. For example, silane coupling agents, zircon coupling agents, titanium coupling agents, etc. are used. can do In addition, release agents such as paraffin, wax, light oil, machine oil, spindle oil, insulating oil, waste oil, vegetable oil, fatty acid ester, organic acid, mica, vermiculite, fluorine release agent, silicone release agent, etc. is also available. Each of these additives is used in a proportion of about 0.1 to 10 parts by weight, preferably about 0.5 to 5 parts by weight, per 100 parts by weight of the phenolic resin.
　ところで、上述の如き本発明に従う鋳型用樹脂組成物を用いて鋳型を製造する場合、先ずは鋳型造型用材料（ＲＣＳ）を作製し、かかるＲＣＳを用いて鋳型を製造することが一般的である。ＲＣＳ作製に際しては、鋳型用樹脂組成物と共に耐火性骨材が用いられるところ、耐火性骨材とは、鋳型の基材として機能する耐火性物質であって、従来より、各種の耐火性の粒状乃至は粉状材料が使用されている。具体的には、ケイ砂、人造ケイ砂を始めとして、アルミナサンド、オリビンサンド、ジルコンサンド、クロマイトサンド等の特殊砂や、フェロクロム系スラグ、フェロニッケル系スラグ、転炉スラグ等のスラグ系粒子；アルミナ系粒子、ムライト系粒子等の人工粒子、及びそれらの再生粒子；アルミナボール、マグネシアクリンカー等を挙げることが出来る。なお、これらの耐火性骨材は、新砂であっても、或は、鋳物砂として鋳型の造型に一回或は複数回使用された再生砂又は回収砂であっても、更には、そのような再生砂や回収砂に新砂を加えて混合せしめてなる混合砂であっても、何等差支えない。そして、そのような耐火性骨材は、一般に、ＡＦＳ指数で４０～２００程度の粒度のものとして、好ましくは６０～１５０程度の粒度のものとして、用いられることとなる。 By the way, when a casting mold is produced using the casting resin composition according to the present invention as described above, it is common to first prepare a casting mold material (RCS) and then use the RCS to produce a casting mold. . In the production of RCS, a refractory aggregate is used together with a resin composition for a mold. Alternatively powdered materials are used. Specifically, including silica sand and artificial silica sand, special sand such as alumina sand, olivine sand, zircon sand, chromite sand, and slag particles such as ferrochrome slag, ferronickel slag, and converter slag; artificial particles such as alumina-based particles and mullite-based particles, and regenerated particles thereof; alumina balls, magnesia clinker, and the like. These refractory aggregates may be new sand, or recycled or recovered sand that has been used once or more than once for molding molds as foundry sand. Mixed sand obtained by adding fresh sand to reclaimed sand or recovered sand and mixing them does not cause any problem. Such refractory aggregates are generally used with a particle size of about 40 to 200, preferably about 60 to 150, in terms of AFS index.
　そのような耐火性骨材と、本発明に従う鋳型用樹脂組成物とを用いて、鋳型造型用材料（ＲＣＳ）を製造するに際しては、公知の各種の配合／被覆手法が、特に限定されることなく、適宜に採用され、例えば、ドライホットコート法やセミホットコート法、コールドコート法、粉末溶剤法等の、従来から公知の方法が、何れも採用され得るところである。中でも、ワールミキサーやスピードミキサー等の混練機内で、一般に１１０～１７０℃程度、好ましくは１２０～１５０℃程度の温度に予め加熱された耐火性骨材（粒子）に対して、バインダ樹脂（所定のフェノール系樹脂）を加え、更に炭化促進剤や必要に応じて選択される他の添加剤を加えて、混練した後、ヘキサメチレンテトラミン等の所定の硬化剤や硬化促進剤を加えると共に、送風冷却によって、塊状内容物を粒状に崩壊させ、次いで、ステアリン酸カルシウム（滑剤）を加える、所謂ドライホットコート法が、有利に採用されることとなる。 When producing a mold making material (RCS) using such a refractory aggregate and the foundry resin composition according to the present invention, various known compounding/coating techniques are particularly limited. Any conventionally known method such as a dry hot coating method, a semi-hot coating method, a cold coating method, a powder solvent method, etc., can be used as appropriate. Among them, a binder resin (predetermined Phenolic resin) is added, a carbonization accelerator and other additives selected as necessary are added, and after kneading, a predetermined curing agent such as hexamethylenetetramine and a curing accelerator are added, and air cooling Therefore, a so-called dry hot coating method, in which the lump content is broken into granules and then calcium stearate (lubricant) is added, is advantageously employed.
　なお、本発明の鋳型用樹脂組成物と耐火性骨材とを混練せしめるタイミングは、当業者の知識に基づいて適宜に選定され得るところ、例えば、フェノール樹脂等に各成分を添加し、混合して鋳型用樹脂組成物を予め調製し、この調製した組成物を耐火性骨材に添加して混練せしめることの他、耐火性骨材に対して、鋳型用樹脂組成物を構成する各成分を順次、添加しながら混練せしめることも可能である。また、炭化促進剤は、フェノール樹脂に対して混合したり、全成分を同時に混合したりすることも可能である。更に、炭化促進剤等の添加剤の添加量が多い場合等においては、フェノール樹脂と、耐火骨材及びフェノール樹脂の混練後の両方で添加する等の分割した添加方式を採用することも可能である。 The timing of kneading the molding resin composition of the present invention and the refractory aggregate can be appropriately selected based on the knowledge of those skilled in the art. In addition to preparing a resin composition for casting molds in advance, adding this prepared composition to refractory aggregates and kneading them, each component constituting the resin composition for casting molds is added to the refractory aggregates. It is also possible to knead while adding them sequentially. Also, the carbonization accelerator can be mixed with the phenolic resin, or all components can be mixed at the same time. Furthermore, when a large amount of additives such as a carbonization accelerator is added, it is possible to adopt a divided addition method such as adding both the phenol resin and the refractory aggregate and phenol resin after kneading. be.
　また、上述の如くして得られる鋳型造型用材料を用いて、目的とするシェルモールド鋳型の如き鋳型を造型するに際しては、かかる鋳型造型用材料（ＲＣＳ）の加熱硬化を図るべく、加熱下において、目的とする鋳型の造型が行なわれることとなるが、そのような加熱造型方法としては、特に限定されるものではなく、従来から公知の手法が、何れも、有利に用いられ得ることとなる。例えば、上述せる如き鋳型造型用材料を、目的とする鋳型を与える所望の成形空間を有する、１５０～３００℃程度に加熱された成形型内に、重力落下方式や吹込方式等によって充填し、硬化させた後、かかる成形型から、その硬化した鋳型を抜型することにより、目的とする鋳造用鋳型を得ることが出来るのである。なお、そのような鋳造用鋳型は、有利には、５０％以上の充填率において造型されてなるものであって、そのような充填率が実現されることにより、鋳型内部構造が石垣構造をとり易くなって、溶湯の侵入を阻止したり、鋳型からのガス圧力を有利に高めることが可能となるのである。また、そのような鋳型の充填率は、公知の手法にて測定可能であり、例えば、特開２０１９－１７７４０２号公報の段落［００６０］に明らかにされている如き手法を採用することが出来る。 In addition, when using the mold-making material obtained as described above to mold a mold such as the desired shell mold mold, the mold-making material (RCS) is heated to harden by heating. , The desired mold is molded, but such a heat molding method is not particularly limited, and any conventionally known method can be advantageously used. . For example, the mold-making material as described above is filled into a mold heated to about 150 to 300° C., which has a desired molding space that provides the desired mold, by a gravity drop method, a blow method, or the like, and cured. After that, the desired casting mold can be obtained by removing the hardened mold from the mold. In addition, such a casting mold is advantageously molded at a filling rate of 50% or more, and by realizing such a filling rate, the internal structure of the mold takes a stone wall structure. This makes it possible to prevent the intrusion of molten metal and advantageously increase the gas pressure from the mold. In addition, such a mold filling rate can be measured by a known method, and for example, a method as disclosed in paragraph [0060] of JP-A-2019-177402 can be employed.
　そして、このようにして得られた鋳型にあっては、耐焼付き性の如き、前述せるような優れた特徴が、有利に付与せしめられ得たものであって、特に、鋳鉄や鋳鋼、ＦＣＤ等の鉄系溶湯の鋳造に有利に用いられて、その特徴がより一層効果的に発揮せしめられ得るものである。 The mold thus obtained is advantageously endowed with the above-mentioned excellent features such as seizure resistance. It can be advantageously used for casting of iron-based molten metal, and its characteristics can be exhibited more effectively.
　以下に、本発明の幾つかの実施例を示し、本発明を更に具体的に明らかにすることとするが、本発明が、そのような実施例の記載によって、何等の制約をも受けるものでないことは、言うまでもないところである。また、本発明には、以下の実施例の他にも、更には上記した具体的記述以外にも、本発明の趣旨を逸脱しない限りにおいて、当業者の知識に基づいて、種々なる変更、修正、改良等が加え得るものであることが、理解されるべきである。なお、以下の実施例や比較例における部及び百分率は何れも質量基準にて示されるものである。フェノール樹脂のゲル濾過クロマトグラフ測定、硬化物のガス発生量の測定、並びに焼付き・鋳肌の評価は、それぞれ、以下のようにして行なった。 Some examples of the present invention are shown below to clarify the present invention more specifically, but the present invention is not limited by the description of such examples. It goes without saying. In addition to the following examples and the specific descriptions above, the present invention includes various changes and modifications based on the knowledge of those skilled in the art as long as they do not depart from the spirit of the present invention. , improvements, etc. may be added. All parts and percentages in the following examples and comparative examples are shown on a mass basis. Gel filtration chromatographic measurement of the phenolic resin, measurement of the amount of gas generated from the cured product, and evaluation of seizure and casting surface were carried out as follows.
－フェノール樹脂のゲル濾過クロマトグラフ測定（ＧＰＣ測定）－
　後述するフェノール樹脂Ａ～Ｄについて、東ソー株式会社製のゲル濾過クロマトグラフ（商品名：ＨＬＣ８３２０ＧＰＣ、カラム：Ｇ１０００ＨＸＬ＋Ｇ２０００ＨＸＬ、検出器：ＵＶ２５４ｎｍ、キャリア：テトラヒドロフラン１ｍＬ／分、カラム温度：４０℃）を用いて測定する。面積百分率法に倣い、測定結果として得られた分子量分布の全面積（ピークの全面積）に対する、フェノール類モノマーのピーク面積及びフェノール類ダイマーのピーク面積の合計値の割合（％）を算出する。なお、これ以後、かかる合計値の割合（％）を、単に「面積比率（％）」という。フェノール樹脂Ａ～Ｄの面積比率について、各々、下記表１～表３に示す。また、フェノール樹脂Ａ～Ｄのうちの何れか二種を用いる実施例９～１４，実施例１６、比較例４及び比較例５については、下記表２又は下記表３に示す割合において混合したフェノール樹脂の混合物を試料として、ＧＰＣ測定を行ない、その測定結果より算出される面積比率（％）を下記表２及び表３に示す。 -Gel filtration chromatographic measurement (GPC measurement) of phenolic resin-
Phenolic resins A to D described later are measured using a gel filtration chromatograph manufactured by Tosoh Corporation (trade name: HLC8320GPC, column: G1000HXL+G2000HXL, detector: UV254 nm, carrier: tetrahydrofuran 1 mL/min, column temperature: 40°C). do. According to the area percentage method, the ratio (%) of the total value of the peak area of the phenolic monomer and the peak area of the phenolic dimer to the total area of the molecular weight distribution (total area of the peaks) obtained as the measurement result is calculated. Hereinafter, the ratio (%) of the total value is simply referred to as "area ratio (%)". The area ratios of the phenol resins A to D are shown in Tables 1 to 3 below, respectively. In addition, for Examples 9 to 14, Example 16, Comparative Example 4, and Comparative Example 5 using any two of the phenolic resins A to D, phenol mixed at the ratio shown in Table 2 or Table 3 below Using the resin mixture as a sample, GPC measurement was performed, and the area ratio (%) calculated from the measurement results is shown in Tables 2 and 3 below.
－硬化物のガス発生量の測定－
　以下の実施例及び比較例に係る鋳型用樹脂組成物について、各々、成分によっては必要に応じて粉砕し、混合した後、樹脂組成物をアルミカップに入れ、アルミカップを約１５０℃に加熱した金属プレート上に載置し、カップ内の樹脂組成物が熱溶融した後、５分間、カップ内を薬さじで混ぜながら硬化させる。その後、アルミカップを、金属プレート上から１５０℃に加熱された恒温恒湿機内に移し、恒温恒湿機内に３０分間、載置して、アルミカップ内の樹脂組成物を完全に硬化させる。得られた樹脂組成物の硬化物を粉砕し、その粉砕物を銅管に投入してガラスウールで封止することにより、試料とする。かかる試料を、ガス発生量測定機における、８５０℃の還元雰囲気とされている炉内に載置し、かかる載置の直後から、粉砕物より発生するガス量を測定する。ガスの発生が終了するまで測定を続け、測定結果より、試料の炉内への載置直後から２０秒が経過するまでに発生するガス量と、ガスの総発生量とを算出し、それらの算出結果より、ガスの総発生量（Ａ）に対する２０秒が経過するまでに発生するガス量（ａ）の割合（％）を算出する。なお、本発明の理解を容易にすべく、実施例１及び比較例１に係る各鋳型用樹脂組成物についてのガス発生量の測定結果を、図１にグラフとして示す。 - Measurement of gas generation amount of cured product -
The resin compositions for molds according to the following examples and comparative examples were pulverized and mixed as necessary depending on the components, then the resin compositions were placed in an aluminum cup, and the aluminum cup was heated to about 150°C. It is placed on a metal plate, and after the resin composition in the cup is thermally melted, it is cured for 5 minutes while stirring the inside of the cup with a spatula. After that, the aluminum cup is transferred from the metal plate to a thermo-hygrostat heated to 150° C. and placed in the thermo-hygrostat for 30 minutes to completely cure the resin composition in the aluminum cup. A cured product of the obtained resin composition is pulverized, and the pulverized product is put into a copper tube and sealed with glass wool to obtain a sample. The sample is placed in a furnace having a reducing atmosphere at 850° C. in a gas generation amount measuring machine, and the amount of gas generated from the pulverized material is measured immediately after the placement. The measurement is continued until the generation of gas is finished, and from the measurement results, the amount of gas generated in 20 seconds from immediately after placing the sample in the furnace and the total amount of gas generated are calculated. From the calculation result, the ratio (%) of the amount of gas (a) generated within 20 seconds to the total amount of gas generated (A) is calculated. In order to facilitate understanding of the present invention, the measurement results of the amount of gas generated for each mold resin composition according to Example 1 and Comparative Example 1 are shown in FIG. 1 as a graph.
－焼付き・鋳肌の評価－
　先ず、図２に示されるように、予め常温自硬性砂で作製された、上部に溶湯注入口２と下部に中子の幅木固定部４とを有する半割れ中空主型６（キャビティ直径：６ｃｍ、高さ：６ｃｍ）の内に、２５０℃に熱した金型に各々の鋳型造型用材料を吹込み充填し、１２０秒間加熱することで造型した、幅木部８を有する円形無空中子１０（直径：５ｃｍ、高さ：５ｃｍ）を、幅木固定部４で接着固定した後、更に半割れ中空主型６を相互に接着固定して、鋳造試験用砂型１２を作製する。なお、鋳造時の湯漏れを防ぐために、接着した主型を万力等でクランプするか、針金を巻いてしっかりと固定する。次に、この鋳造試験用砂型１２の溶湯注入口２から鋳鉄溶湯：ＦＣ２００（温度：１３８０℃±４０℃）を注湯し、凝固せしめた後、主型６及び中子１０を壊して、図３に示される如き、円筒状の鋳物１６を取り出す。そして、この得られた鋳物１６を半分に切断して、焼付き及び鋳肌（鋳物の肌）の状況を目視及び手触りにて確認し、以下に示す基準に従って、それぞれ、３段階及び４段階で評価する。
　　＜焼付き＞
　　○：焼付きは認められない
　　△：鋳物の一部に焼付きが認められる
　　×：鋳物の全面に焼付きが認められる
　　＜鋳肌＞
　　◎：鋳物全体の鋳肌は平滑であり、手の引っ掛かりもない
　　〇：鋳物全体の鋳肌は平滑であるが、一部にざらつきがある
　　△：鋳物全体の鋳肌にざらつきがあり、一部に引っ掛かりがある
　　×：鋳物全体の鋳肌にざらつき、引っ掛かりがある －Evaluation of seizure and casting surface－
First, as shown in FIG. 2, a half hollow main mold 6 (cavity diameter: 6 cm, height: 6 cm), a circular airless element having a skirting part 8, which was molded by blowing and filling each mold molding material into a mold heated to 250 ° C. and heating for 120 seconds. 10 (diameter: 5 cm, height: 5 cm) is adhesively fixed by the baseboard fixing part 4, and then the half-split hollow main mold 6 is adhesively fixed to each other to prepare a sand mold 12 for casting test. In addition, in order to prevent molten metal from leaking during casting, the bonded main mold is clamped with a vise or the like, or tightly fixed by wrapping it with a wire. Next, molten cast iron: FC200 (temperature: 1380° C.±40° C.) is poured from the molten metal injection port 2 of the sand mold 12 for casting test and allowed to solidify. 3, a cylindrical casting 16 is removed. Then, the resulting casting 16 is cut in half, and the conditions of seizure and casting surface (casting surface) are visually and tactilely confirmed. evaluate.
<Seizure>
○: Seizure is not observed △: Seizure is observed in part of the casting ×: Seizure is observed on the entire surface of the casting <Casting surface>
◎: Overall casting surface is smooth and does not catch fingers ○: Overall casting surface is smooth, but some parts are rough △: Overall casting surface is rough, but some parts are rough There is a catch ×: The casting surface of the entire casting is rough and has a catch
－フェノール樹脂Ａの製造－
　温度計、撹拌装置及びコンデンサを備えた反応容器に、フェノールの３５０部、４７％ホルマリンの１１８部、９２％パラホルムアルデヒドの３０部、及び、蓚酸の３部を投入した。次いで、容器内を撹拌しながら反応容器を徐々に昇温して、還流温度に到達せしめた後、還流温度に維持した状態で９０分間、還流反応させ、更に、内容物の温度が１８０℃になるまで、加熱しながら減圧濃縮することにより、ノボラック型フェノール樹脂であるフェノール樹脂Ａの４３０部を得た。なお、かかるフェノール樹脂Ａの面積比率（ＧＰＣ測定において、ピークの全面積に対する、フェノール類モノマーのピーク面積及びフェノール類ダイマーのピーク面積の合計値の割合）は１３．９％であった。 -Production of Phenolic Resin A-
A reaction vessel equipped with a thermometer, stirrer and condenser was charged with 350 parts phenol, 118 parts 47% formalin, 30 parts 92% paraformaldehyde and 3 parts oxalic acid. Next, the temperature of the reaction vessel was gradually raised while stirring the inside of the vessel until it reached the reflux temperature, and then the reflux reaction was carried out for 90 minutes while maintaining the reflux temperature. 430 parts of phenolic resin A, which is a novolac-type phenolic resin, was obtained by concentrating under reduced pressure while heating until the content reached . The area ratio of the phenolic resin A (in GPC measurement, the ratio of the sum of the peak area of the phenolic monomer and the peak area of the phenolic dimer to the total peak area) was 13.9%.
－フェノール樹脂Ｂの製造－
　温度計、撹拌装置及びコンデンサを備えた反応容器に、フェノールの１１５部、４７％ホルマリンの１１０部、ビスフェノールＡの４５０部、水の１００部、及び、蓚酸の２部を投入した。次いで、容器内を撹拌しながら反応容器を徐々に昇温して、還流温度に到達せしめた後、還流温度に維持した状態で９０分間、還流反応させ、更に、内容物の温度が１７０℃になるまで、加熱しながら減圧濃縮することにより、変性ノボラック型フェノール樹脂であるフェノール樹脂Ｂの６００部を得た。なお、かかるフェノール樹脂Ｂの面積比率（ＧＰＣ測定において、ピークの全面積に対する、フェノール類モノマーのピーク面積及びフェノール類ダイマーのピーク面積の合計値の割合）は２６．０％であった。 -Production of Phenolic Resin B-
A reaction vessel equipped with a thermometer, stirrer and condenser was charged with 115 parts phenol, 110 parts 47% formalin, 450 parts bisphenol A, 100 parts water and 2 parts oxalic acid. Next, the temperature of the reaction vessel was gradually raised while stirring the inside of the vessel until it reached the reflux temperature, and then the reflux reaction was carried out for 90 minutes while maintaining the reflux temperature. 600 parts of phenolic resin B, which is a modified novolac-type phenolic resin, was obtained by concentrating under reduced pressure while heating until the content reached 600 parts. The area ratio of the phenolic resin B (in GPC measurement, the ratio of the sum of the peak area of the phenolic monomer and the peak area of the phenolic dimer to the total peak area) was 26.0%.
－フェノール樹脂Ｃの製造－
　温度計、撹拌装置及びコンデンサを備えた反応容器に、フェノールの６８０部、４７％ホルマリンの５６５部、及び、ヘキサメチレンテトラミンの１０１部を投入した。次いで、容器内を撹拌しながら、約６０分かけて容器内を７０℃まで昇温させ、その後５時間、保持することにより、反応を進行させた。その後、内容物の温度が９０℃になるまで、加熱しながら減圧脱水することにより、レゾール型フェノール樹脂であるフェノール樹脂Ｃの７００部を得た。なお、かかるフェノール樹脂Ｃの面積比率（ＧＰＣ測定において、ピークの全面積に対する、フェノール類モノマーのピーク面積及びフェノール類ダイマーのピーク面積の合計値の割合）は３４．０％であった。
-Production of Phenolic Resin C-
A reaction vessel equipped with a thermometer, stirrer and condenser was charged with 680 parts of phenol, 565 parts of 47% formalin, and 101 parts of hexamethylenetetramine. Next, while stirring the inside of the vessel, the inside of the vessel was heated to 70° C. over about 60 minutes, and then held for 5 hours to advance the reaction. Thereafter, dehydration was performed under reduced pressure while heating until the content reached a temperature of 90° C., thereby obtaining 700 parts of phenol resin C, which is a resol-type phenol resin. The area ratio of the phenolic resin C (in GPC measurement, the ratio of the sum of the peak area of the phenolic monomer and the peak area of the phenolic dimer to the total peak area) was 34.0%.
－フェノール樹脂Ｄの製造－
　温度計、撹拌装置及びコンデンサを備えた反応容器に、フェノールの４００部、４７％ホルマリンの２１７部、及び、蓚酸の３部を投入した。次いで、容器内を撹拌しながら反応容器を徐々に昇温して、還流温度に到達せしめた後、還流温度に維持した状態で９０分間、還流反応させ、更に、内容物の温度が１８０℃になるまで、加熱しながら減圧濃縮することにより、ノボラック型フェノール樹脂であるフェノール樹脂Ａの５７０部を得た。なお、かかるフェノール樹脂Ｄの面積比率（ＧＰＣ測定において、ピークの全面積に対する、フェノール類モノマーのピーク面積及びフェノール類ダイマーのピーク面積の合計値の割合）は１０．６％であった。 -Production of Phenolic Resin D-
A reaction vessel equipped with a thermometer, stirrer and condenser was charged with 400 parts phenol, 217 parts 47% formalin, and 3 parts oxalic acid. Next, the temperature of the reaction vessel was gradually raised while stirring the inside of the vessel until it reached the reflux temperature, and then the reflux reaction was carried out for 90 minutes while maintaining the reflux temperature. 570 parts of phenolic resin A, which is a novolac-type phenolic resin, was obtained by concentrating under reduced pressure while heating until the content reached . The area ratio of the phenolic resin D (in GPC measurement, the ratio of the sum of the peak area of the phenolic monomer and the peak area of the phenolic dimer to the total peak area) was 10.6%.
－実施例１－
　先ず、鋳型用樹脂組成物の構成成分として、フェノール樹脂Ａの１００部と、炭化促進剤としての脂肪族縮合リン酸エステル：ＰＮＸ（商品名：Ｆｙｒｏｌ　ＰＮＸ－ＬＥ、ＩＣＬ　ＪＡＰＡＮ株式会社製）の１０部と、硬化剤としてのヘキサメチレンテトラミンの１５部を水に溶解してなるものとを準備した。一方、耐火性骨材として、フラタリーサンドと再生ケイ砂の２：８の混合砂を準備した。混合砂を約１４０℃の温度に予熱した後、この混合砂の５０００部と、鋳型用樹脂組成物のフェノール樹脂Ａ及び炭化促進剤（ＰＮＸ）とを、順次ワールミキサーに投入して、６０秒間混練した。更に、水に溶解せしめた硬化剤（ヘキサメチレンテトラミン）を添加して、送風冷却し、その後、ステアリン酸カルシウムの５部を添加して、シェルモールド用鋳型材料（鋳型造型用材料）を得た。 -Example 1-
First, 100 parts of a phenolic resin A and 10 parts of an aliphatic condensed phosphate: PNX (trade name: Fyrol PNX-LE, manufactured by ICL JAPAN Co., Ltd.) as a carbonization accelerator as components of a resin composition for a mold. and 15 parts of hexamethylenetetramine as a curing agent dissolved in water. On the other hand, a mixed sand of 2:8 of flattery sand and recycled silica sand was prepared as a refractory aggregate. After preheating the mixed sand to a temperature of about 140° C., 5000 parts of this mixed sand, the phenolic resin A of the mold resin composition and the carbonization accelerator (PNX) were sequentially put into a whirl mixer and mixed for 60 seconds. Kneaded. Further, a hardening agent (hexamethylenetetramine) dissolved in water was added, air cooled, and then 5 parts of calcium stearate was added to obtain a mold material for shell mold (molding material).
－実施例２－
　炭化促進剤として、ＰＮＸに代えて、芳香族縮合リン酸エステル（商品名：ＣＲ－７３３Ｓ、大八化学工業株式会社）を用いたこと以外は、実施例１と同様の手法に従い、シェルモールド用鋳型材料を得た。 -Example 2-
For shell molds, following the same procedure as in Example 1, except that an aromatic condensed phosphate ester (trade name: CR-733S, Daihachi Chemical Industry Co., Ltd.) was used instead of PNX as the carbonization accelerator. A mold material was obtained.
－実施例３－
　炭化促進剤として、ＰＮＸに代えて、有機ハロゲン化物である２，４，６－トリブロモフェノール（ＴＢＰ）を用いたこと以外は、実施例１と同様の手法に従い、シェルモールド用鋳型材料を得た。 -Example 3-
A mold material for a shell mold was obtained in the same manner as in Example 1, except that 2,4,6-tribromophenol (TBP), which is an organic halide, was used as the carbonization accelerator instead of PNX. rice field.
－実施例４－
　炭化促進剤として、ＰＮＸに代えて、有機ハロゲン化物であるテトラブロモビスフェノールＡ（ＴＢＢＡ）を用いたこと以外は、実施例１と同様の手法に従い、シェルモールド用鋳型材料を得た。 -Example 4-
A mold material for a shell mold was obtained in the same manner as in Example 1, except that tetrabromobisphenol A (TBBA), which is an organic halide, was used as the carbonization accelerator instead of PNX.
－実施例５－
　炭化促進剤（ＰＮＸ）の使用量を３部としたこと以外は、実施例１と同様の手法に従い、シェルモールド用鋳型材料を得た。 -Example 5-
A mold material for a shell mold was obtained in the same manner as in Example 1, except that the amount of carbonization accelerator (PNX) used was 3 parts.
－実施例６－
　フェノール樹脂Ａに代えてフェノール樹脂Ｂを用いたこと以外は、実施例１と同様の手法に従い、シェルモールド用鋳型材料を得た。 -Example 6-
A mold material for shell mold was obtained in the same manner as in Example 1, except that phenol resin B was used instead of phenol resin A.
－実施例７－
　フェノール樹脂Ａに代えてフェノール樹脂Ｂを用いたこと以外は、実施例２と同様の手法に従い、シェルモールド用鋳型材料を得た。 -Example 7-
A mold material for shell mold was obtained in the same manner as in Example 2, except that phenol resin B was used instead of phenol resin A.
－実施例８－
　炭化促進剤（ＣＲ－７３３Ｓ）の使用量を３部としたこと以外は、実施例７と同様の手法に従い、シェルモールド用鋳型材料を得た。 -Example 8-
A mold material for a shell mold was obtained in the same manner as in Example 7, except that the amount of carbonization accelerator (CR-733S) used was 3 parts.
－実施例９－
　フェノール樹脂Ａの１００部に代えて、フェノール樹脂Ａの７５部とフェノール樹脂Ｃの２５部とを使用し、また、硬化剤（ヘキサメチレンテトラミン）の使用量を４部としたこと以外は、実施例１と同様の手法に従い、シェルモールド用鋳型材料を得た。 -Example 9-
Instead of 100 parts of phenolic resin A, 75 parts of phenolic resin A and 25 parts of phenolic resin C were used, and the amount of curing agent (hexamethylenetetramine) used was 4 parts. A mold material for a shell mold was obtained in the same manner as in Example 1.
－実施例１０－
　フェノール樹脂Ａの１００部に代えて、フェノール樹脂Ａの７５部とフェノール樹脂Ｃの２５部とを使用し、また、硬化剤（ヘキサメチレンテトラミン）の使用量を４部としたこと以外は、実施例２と同様の手法に従い、シェルモールド用鋳型材料を得た。 -Example 10-
Instead of 100 parts of phenolic resin A, 75 parts of phenolic resin A and 25 parts of phenolic resin C were used, and the amount of curing agent (hexamethylenetetramine) used was 4 parts. A shell mold material was obtained in the same manner as in Example 2.
－実施例１１－
　フェノール樹脂Ａの１００部に代えて、フェノール樹脂Ａの７５部とフェノール樹脂Ｃの２５部とを使用し、また、硬化剤（ヘキサメチレンテトラミン）の使用量を４部としたこと以外は、実施例３と同様の手法に従い、シェルモールド用鋳型材料を得た。 -Example 11-
Instead of 100 parts of phenolic resin A, 75 parts of phenolic resin A and 25 parts of phenolic resin C were used, and the amount of curing agent (hexamethylenetetramine) used was 4 parts. A shell mold material was obtained in the same manner as in Example 3.
－実施例１２－
　フェノール樹脂Ａの１００部に代えて、フェノール樹脂Ａの７５部とフェノール樹脂Ｃの２５部とを使用し、また、硬化剤（ヘキサメチレンテトラミン）の使用量を４部としたこと以外は、実施例４と同様の手法に従い、シェルモールド用鋳型材料を得た。 -Example 12-
Instead of 100 parts of phenolic resin A, 75 parts of phenolic resin A and 25 parts of phenolic resin C were used, and the amount of curing agent (hexamethylenetetramine) used was 4 parts. A shell mold material was obtained in the same manner as in Example 4.
－実施例１３－
　フェノール樹脂Ａの１００部に代えて、フェノール樹脂Ｂの７５部とフェノール樹脂Ｃの２５部とを使用し、また、硬化剤（ヘキサメチレンテトラミン）の使用量を４部としたこと以外は、実施例１と同様の手法に従い、シェルモールド用鋳型材料を得た。 -Example 13-
Instead of 100 parts of phenolic resin A, 75 parts of phenolic resin B and 25 parts of phenolic resin C were used, and the amount of curing agent (hexamethylenetetramine) used was 4 parts. A mold material for a shell mold was obtained in the same manner as in Example 1.
－実施例１４－
　フェノール樹脂Ａの１００部に代えて、フェノール樹脂Ｂの７５部とフェノール樹脂Ｃの２５部とを使用し、また、硬化剤（ヘキサメチレンテトラミン）の使用量を４部としたこと以外は、実施例２と同様の手法に従い、シェルモールド用鋳型材料を得た。 -Example 14-
Instead of 100 parts of phenolic resin A, 75 parts of phenolic resin B and 25 parts of phenolic resin C were used, and the amount of curing agent (hexamethylenetetramine) used was 4 parts. A shell mold material was obtained in the same manner as in Example 2.
－実施例１５－
　フェノール樹脂Ａに代えてフェノール樹脂Ｃを使用し、また、硬化剤（ヘキサメチレンテトラミン）を使用しなかったこと以外は、実施例１と同様の手法に従い、シェルモールド用鋳型材料を得た。 -Example 15-
A mold material for shell mold was obtained in the same manner as in Example 1, except that phenolic resin C was used instead of phenolic resin A and the curing agent (hexamethylenetetramine) was not used.
－実施例１６－
　フェノール樹脂Ａの１００部に代えて、フェノール樹脂Ｃの２５部とフェノール樹脂Ｄの７５部とを使用し、また、硬化剤（ヘキサメチレンテトラミン）の使用量を４部としたこと以外は、実施例１と同様の手法に従い、シェルモールド用鋳型材料を得た。 -Example 16-
Instead of 100 parts of phenolic resin A, 25 parts of phenolic resin C and 75 parts of phenolic resin D were used, and the amount of curing agent (hexamethylenetetramine) used was 4 parts. A mold material for a shell mold was obtained in the same manner as in Example 1.
－比較例１－
　フェノール樹脂Ａに代えてフェノール樹脂Ｄを使用したこと以外は、実施例１と同様の手法に従い、シェルモールド用鋳型材料を得た。 -Comparative Example 1-
A mold material for shell mold was obtained in the same manner as in Example 1, except that phenolic resin D was used instead of phenolic resin A.
－比較例２－
　炭化促進剤（ＰＮＸ）を使用しなかったこと以外は、実施例１と同様の手法に従い、シェルモールド用鋳型材料を得た。 -Comparative Example 2-
A mold material for a shell mold was obtained in the same manner as in Example 1, except that no carbonization accelerator (PNX) was used.
－比較例３－
　炭化促進剤（ＣＲ－７３３Ｓ）を使用しなかったこと以外は、実施例６と同様の手法に従い、シェルモールド用鋳型材料を得た。 -Comparative Example 3-
A mold material for a shell mold was obtained in the same manner as in Example 6, except that the carbonization accelerator (CR-733S) was not used.
－比較例４－
　炭化促進剤（ＴＢＰ）を使用しなかったこと以外は、実施例９と同様の手法に従い、シェルモールド用鋳型材料を得た。 -Comparative Example 4-
A mold material for a shell mold was obtained in the same manner as in Example 9, except that no carbonization accelerator (TBP) was used.
－比較例５－
　炭化促進剤（ＰＮＸ）を使用しなかったこと以外は、実施例１３と同様の手法に従い、シェルモールド用鋳型材料を得た。 -Comparative Example 5-
A mold material for a shell mold was obtained in the same manner as in Example 13, except that no carbonization accelerator (PNX) was used.
－比較例６－
　炭化促進剤（ＰＮＸ）を用いなかったこと以外は、実施例１５と同様の手法に従い、シェルモールド用鋳型材料を得た。 -Comparative Example 6-
A mold material for shell mold was obtained in the same manner as in Example 15, except that no carbonization accelerator (PNX) was used.
－比較例７－
　フェノール樹脂Ａに代えてフェノール樹脂Ｄを使用し、また、炭化促進剤（ＰＮＸ）を使用しなかったこと以外は、実施例１と同様の手法に従い、シェルモールド用鋳型材料を得た。 -Comparative Example 7-
A mold material for a shell mold was obtained in the same manner as in Example 1, except that phenolic resin D was used instead of phenolic resin A and no carbonization accelerator (PNX) was used.
－比較例８－
　炭化促進剤（ＰＮＸ）の使用量を１部としたこと以外は、実施例１と同様の手法に従い、シェルモールド用鋳型材料を得た。 -Comparative Example 8-
A mold material for a shell mold was obtained in the same manner as in Example 1, except that the amount of carbonization accelerator (PNX) used was 1 part.
Figure JPOXMLDOC01-appb-T000001
Figure JPOXMLDOC01-appb-T000001
Figure JPOXMLDOC01-appb-T000002
Figure JPOXMLDOC01-appb-T000002
Figure JPOXMLDOC01-appb-T000003
Figure JPOXMLDOC01-appb-T000003
　かかる表１～表３の結果からも明らかなように、本発明に従う鋳型用樹脂組成物（実施例１～実施例１６）を用いて得られたシェルモールド用鋳型材料にあっては、何れも、焼付きの発生が効果的に抑制乃至は阻止され得ると共に、得られる鋳物の鋳肌も良好なものとなり、品質に優れた鋳物を得ることが出来ることが認められる。 As is clear from the results in Tables 1 to 3, all of the mold materials for shell molds obtained using the resin compositions for molds according to the present invention (Examples 1 to 16) In addition, the occurrence of seizure can be effectively suppressed or prevented, and the casting surface of the obtained casting is improved, so that a casting of excellent quality can be obtained.
　これに対して、面積比率が１３．０％未満のフェノール樹脂を用いた比較例１及び比較例７に係る各樹脂組成物は、それらを用いて得られるシェルモールド用鋳型材料において、焼付きや鋳肌が不良なものとなることが認められ、また、炭化促進剤を含有しない樹脂組成物（比較例２～比較例６）や、十分な量の炭化促進剤が添加されていない樹脂組成物（比較例８）についても、それら各々を用いて得られるシェルモールド用鋳型材料において、焼付きや鋳肌が不良なものとなることが認められた。 On the other hand, the resin compositions according to Comparative Examples 1 and 7 using a phenolic resin having an area ratio of less than 13.0% caused seizure and It was found that the casting surface was poor, and resin compositions containing no carbonization accelerator (Comparative Examples 2 to 6) and resin compositions to which a sufficient amount of carbonization accelerator was not added. Also in (Comparative Example 8), it was confirmed that the casting mold material for shell mold obtained by using each of them had poor seizure and poor casting surface.
　　２　溶湯注入口　　　　　　　　　　　　４　幅木固定部
　　６　主型　　　　　　　　　　　　　　　８　幅木部
　１０　中子　　　　　　　　　　　　　　１２　砂型
　１４　廃中子排出口　　　　　　　　　　１６　鋳物 2 Molten metal injection port 4 Baseboard fixing part 6 Main mold 8 Baseboard part 10 Core 12 Sand mold 14 Waste core discharge port 16 Casting

Claims (6)

  1. 　ゲル濾過クロマトグラフ測定におけるピークの総面積に対する、フェノール類モノマーのピーク面積及びフェノール類ダイマーのピーク面積の合計値の割合が１３．０％以上であるフェノール樹脂と、かかるフェノール樹脂の炭化を促進する炭化促進剤とを含み、
    　１５０℃で完全硬化させた硬化物の、８５０℃の還元雰囲気下で発生するガス量の測定において、発生するガスの総量に対する測定開始から２０秒間で発生するガス量の割合が５０％以上である、
    ことを特徴とする鋳型用樹脂組成物。     A phenolic resin having a ratio of the total value of the peak area of the phenolic monomer and the peak area of the phenolic dimer to the total area of the peaks in gel filtration chromatograph measurement is 13.0% or more, and promoting carbonization of the phenolic resin and a carbonization accelerator,
    In the measurement of the amount of gas generated in a reducing atmosphere at 850°C from a cured product completely cured at 150°C, the ratio of the amount of gas generated within 20 seconds from the start of measurement to the total amount of gas generated is 50% or more. ,
    A casting mold resin composition characterized by:
  2. 　前記フェノール樹脂が、ノボラック型フェノール樹脂、変性ノボラック型フェノール樹脂及びレゾール型フェノール樹脂からなる群より選ばれる一種以上のものである請求項１に記載の鋳型用樹脂組成物。 The resin composition for molds according to claim 1, wherein the phenolic resin is one or more selected from the group consisting of novolac-type phenolic resins, modified novolac-type phenolic resins and resol-type phenolic resins.
  3. 　前記炭化促進剤が、有機リン酸エステル及び／又は有機ハロゲン化物である請求項１又は請求項２に記載の鋳型用樹脂組成物。 The resin composition for molds according to claim 1 or claim 2, wherein the carbonization accelerator is an organic phosphoric acid ester and/or an organic halide.
  4. 　鉄系溶湯の鋳造用鋳型の造型に用いられる請求項１乃至請求項３の何れか１項に記載の鋳型用樹脂組成物。 The resin composition for molds according to any one of claims 1 to 3, which is used for making molds for casting molten iron.
  5. 　請求項１乃至請求項４の何れか１項に記載の鋳型用樹脂組成物と耐火性骨材とを用いてなるレジンコーテッドサンド。 A resin-coated sand made by using the mold resin composition according to any one of claims 1 to 4 and a refractory aggregate.
  6. 　請求項５に記載のレジンコーテッドサンドを用いて造型し、加熱硬化せしめてなる鋳型。
                                                                                         A mold obtained by forming a mold using the resin-coated sand according to claim 5 and curing it by heating.
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Citations (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS5756137A (en) * 1980-09-20 1982-04-03 Toyoda Autom Loom Works Ltd Molding material for shell molding
JPS5978747A (en) * 1982-10-28 1984-05-07 Aisin Chem Co Ltd Resin-coated sand grain for shell mold
JPH06179040A (en) * 1992-12-14 1994-06-28 Kao Corp Resin coated sand for shell mold
JP2005095933A (en) * 2003-09-25 2005-04-14 Sumitomo Bakelite Co Ltd Novolak type phenolic resin for shell mold
WO2007010848A1 (en) * 2005-07-15 2007-01-25 Komatsu Ltd. Resin-coated sand for use in cast steel, casting mold made of the sand, steel casting casted using the casting mold
JP2014161883A (en) * 2013-02-26 2014-09-08 Asahi Organic Chemicals Industry Co Ltd Resin-coated sand for high temperature easily collapsible shell mold, casting mold provided by using the same and manufacturing method of casting
WO2018047893A1 (en) * 2016-09-08 2018-03-15 旭有機材株式会社 Resin composition for shell molding and resin-coated sand obtained using same
JP2019177402A (en) * 2018-03-30 2019-10-17 旭有機材株式会社 Aggregate for a mold and method of producing same

Family Cites Families (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS5881539A (en) * 1981-11-10 1983-05-16 Sumitomo Deyurezu Kk Resin coated sand and its production

Patent Citations (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS5756137A (en) * 1980-09-20 1982-04-03 Toyoda Autom Loom Works Ltd Molding material for shell molding
JPS5978747A (en) * 1982-10-28 1984-05-07 Aisin Chem Co Ltd Resin-coated sand grain for shell mold
JPH06179040A (en) * 1992-12-14 1994-06-28 Kao Corp Resin coated sand for shell mold
JP2005095933A (en) * 2003-09-25 2005-04-14 Sumitomo Bakelite Co Ltd Novolak type phenolic resin for shell mold
WO2007010848A1 (en) * 2005-07-15 2007-01-25 Komatsu Ltd. Resin-coated sand for use in cast steel, casting mold made of the sand, steel casting casted using the casting mold
JP2014161883A (en) * 2013-02-26 2014-09-08 Asahi Organic Chemicals Industry Co Ltd Resin-coated sand for high temperature easily collapsible shell mold, casting mold provided by using the same and manufacturing method of casting
WO2018047893A1 (en) * 2016-09-08 2018-03-15 旭有機材株式会社 Resin composition for shell molding and resin-coated sand obtained using same
JP2019177402A (en) * 2018-03-30 2019-10-17 旭有機材株式会社 Aggregate for a mold and method of producing same

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