JP2018199153A - Hardener composition for mold making - Google Patents

Abstract

An object of the present invention is to provide a mold for molding capable of improving the working environment at the time of molding of a mold using a water-soluble phenol resin as a binder and an ester compound as a curing agent, and at the time of casting using the mold, and the environment around a foundry. To provide a curing agent composition.
A mold forming curing agent composition containing dodecahydro-3a, 6,6,9a-tetramethylnaphtho [2,1-b] furan and / or methyldihydrojasmonate.
[Selection figure] None

Description

  The present invention relates to a curing agent composition for mold making.

Phenolic resins are widely used as binders for molds because of their high heat resistance. In particular, a mold making method using a water-soluble phenol resin as a binder and an ester compound as a curing agent is known, in which there is high heat resistance and sulfur that lowers the casting quality in the binder, Since an element such as phosphorus is not included, a high-quality casting can be manufactured (for example, Patent Document 1). Further, since SOx and H ₂ S due to sulfur are not contained in the pyrolysis gas at the time of casting, the odor at the time of casting is relatively good. However, since a pyrolytic odor generated by the thermal decomposition of the phenol resin itself is generated, further odor improvement during casting is required.

  In order to solve the above-mentioned problem, in Patent Document 2 below, a fragrance is added to the binder composition in order to reduce the odor generated when the mold is formed, that is, the odor caused by the curing of the phenol resin, particularly the odor against the formaldehyde odor. Technology is disclosed.

JP-A-8-99149 JP-A-8-33943

  However, when a fragrance is added to the binder composition, the stability after long-term storage may be slightly inferior.

  The present invention can improve the working environment when casting a mold using a water-soluble phenolic resin as a binder and an ester compound as a curing agent, and a casting factory using the mold, and the environment around a foundry, and Provided is a mold-forming curing agent composition capable of exhibiting a stable effect.

  The present invention relates to a mold making curing containing dodecahydro-3a, 6,6,9a-tetramethylnaphtho [2,1-b] furan and / or methyldimethyl jasmonate (hereinafter sometimes referred to as MDJ). Agent composition.

  According to the present invention, it is possible to improve the working environment when casting a mold using a water-soluble phenol resin as a binder and the ester compound as a curing agent, and the casting environment using the mold and the environment around the foundry. In addition, it is possible to provide a mold-forming curing agent composition capable of exhibiting a stable effect.

<Curing agent composition for mold making>
The mold-forming curing agent composition of the present embodiment (hereinafter also simply referred to as a curing agent composition) is dodecahydro-3a, 6,6,9a-tetramethylnaphtho [2,1-b] furan and / or MDJ. Containing. According to the curing agent composition of the present embodiment, when dodecahydro-3a, 6,6,9a-tetramethylnaphtho [2,1-b] furan and / or MDJ is heated during casting, the water-soluble phenol Odor due to thermal decomposition of the resin can be suppressed. Thereby, it is possible to improve the working environment at the time of molding of the mold using the water-soluble phenol resin as the binder and the ester compound as the curing agent, and the casting environment using the mold and the environment around the foundry. These have a relatively high boiling point, so that when the mold is made at room temperature, the mold does not volatilize much and the effect of suppressing odor is low, but it is maintained in the mold without disappearing at that time, Thereafter, at the time of casting in which high-temperature molten metal is poured into the mold, it is effectively volatilized from the high-temperature mold, and it is possible to suppress odor generated by thermal decomposition of the water-soluble phenol resin. Furthermore, when the hardening | curing agent composition of this embodiment is used, performance can be stably exhibited compared with the case where these are mix | blended in a binder composition. That is, since the binder composition is a strong alkali, these components may be altered in some cases during storage at high temperatures. However, when added to the curing agent composition, the effect can be stably exhibited. .

  The content of dodecahydro-3a, 6,6,9a-tetramethylnaphtho [2,1-b] furan and MDJ in the curing agent composition is preferably 0.0001% by mass or more from the viewpoint of improving the working environment. 0.001% by mass or more is more preferable, and 0.01% by mass or more is more preferable. From the viewpoint of mold strength, the content of dodecahydro-3a, 6,6,9a-tetramethylnaphtho [2,1-b] furan and MDJ in the curing agent composition is preferably 5% by mass or less, and 1% by mass. % Or less is more preferable, 0.5% by mass or less is more preferable, and 0.1% by mass or less is more preferable. The contents of dodecahydro-3a, 6,6,9a-tetramethylnaphtho [2,1-b] furan and MDJ in the curing agent composition are from the viewpoint of improving the working environment and the mold strength. 0.0001-5 mass% is preferable, 0.001-1 mass% is more preferable, 0.01-0.5 mass% is more preferable, 0.01-0.1 mass% is still more preferable.

  The said hardening | curing agent composition contains an ester compound. The said ester compound is a conventionally well-known ester compound which can be used as a hardening | curing agent of water-soluble phenol resin. Examples of the ester compound include lactones or mono- or polyhydric alcohols having 1 to 10 carbon atoms and organic ester compounds derived from organic carboxylic acids having 1 to 10 carbon atoms. γ-butyrolactone, propionlactone, ε-caprolactone, ethyl formate, ethylene glycol diacetate, ethylene glycol monoacetate, triethylene glycol diacetate, triethylene glycol monoacetate, ethyl acetoacetate, dimethyl glutarate, dimethyl adipate, triacetin, etc. Is preferably used.

  The ester compound may be a branched ester compound. Examples of the branched ester compound include dimethyl 2-ethylsuccinate, dimethyl 2-methylglutarate, dimethyl 2-methyladipate, methyl 2-ethylhexanoate, ethyl 2-ethylhexanoate, dimethyl 2-methylsebacate, 2- Dimethyl ethyl azelate, diethyl 2-ethylglutarate, dimethyl 2- (n-propyl) glutarate, diethyl 2- (n-butyl) succinate, dimethyl 2- (n-butyl) succinate, diethyl 2-methylpimelate And dimethyl 2-methylsuberate, and mixtures thereof. Of these, dimethyl 2-ethylsuccinate, dimethyl 2-methylglutarate, and dimethyl 2-methyladipate are preferable because the curing time of the water-soluble phenol resin can be adjusted to a more appropriate range.

  The content of the ester compound in the curing agent composition is preferably 50% by mass or more, and more preferably 60% by mass or more from the viewpoint of mold strength. The content of the ester compound in the curing agent composition is preferably 100% by mass or less and more preferably 99.99% by mass or less from the viewpoint of workability. In addition, the content of the ester compound in the curing agent composition is preferably 50 to 100% by mass, and more preferably 60 to 99.99% by mass from the viewpoint of mold strength and workability.

  The said hardening | curing agent composition may contain another component in the range which does not impair the effect of this invention. For example, the curing agent composition may contain a solvent such as water, alcohols, ether alcohols, etc., for the purpose of uniformly adding to the foundry sand and uniformly mixing with the resin composition. Among these, alcohols and ether alcohols are preferable, and alcohols having 1 to 3 carbon atoms are more preferable from the viewpoint of improving the curing rate of the mold and improving the mold strength. Specific examples of alcohols include methanol, ethanol, propanol, and isopropanol. Methanol and ethanol are preferable, and methanol is more preferable. The content of the solvent in the curing agent composition is preferably 20 to 90% by mass and more preferably 30 to 80% by mass from the viewpoint of improvement in mold strength and solubility in the curing agent composition. Preferably, it is 40-70 mass%.

<Mold production method>
The mold manufacturing method of the present embodiment includes a mold-forming binder composition (hereinafter, also simply referred to as a binder composition) containing refractory particles and a water-soluble phenol resin, and the mold-forming binder. A mixing step of mixing the mold-forming curing agent composition for curing the composition to obtain a mold composition; and a curing step of filling the mold composition in a mold and curing the mold composition. This is a method for producing a mold. According to the mold manufacturing method of this embodiment, it is possible to improve the working environment related to the mold making method using a water-soluble phenol resin as a binder and an ester compound as a curing agent.

[Mixing process]
[Fireproof particles]
As the refractory particles, conventionally known particles such as silica sand, chromite sand, zircon sand, olivine sand, alumina sand, mullite sand, synthetic mullite sand can be used, and used refractory particles are recovered and regenerated. Treated recycled sand can also be used. The refractory particles can be used alone or in combination of two or more.

[Binder composition for mold making]
(Water-soluble phenolic resin)
The water-soluble phenol resin is a resin curable with an ester compound, and is generally obtained by polycondensation of a phenol compound and an aldehyde compound under alkaline conditions. Among these, phenol compounds including phenol, bisphenol A, bisphenol F, cresol, 3,5-xylenol, resorcin, catechol, nonylphenol, p-tert-butylphenol, isopropenylphenol, phenylphenol, and other substituted phenols And mixtures of various phenol compounds such as cashew nut shell liquid can be used alone or in combination. Moreover, as an aldehyde compound, formaldehyde, a furfural, a glyoxal, etc. can be used 1 type or in mixture of 2 or more types. These compounds can be used as an aqueous solution as needed. In addition, monomers capable of condensing with aldehyde compounds such as urea, melamine and cyclohexanone, monovalent aliphatic alcohol compounds such as methanol, ethanol, isopropyl alcohol, normal propyl alcohol and butyl alcohol, water-soluble polymers Polyacrylic acid salt, cellulose derivative polymer, polyvinyl alcohol, lignin derivative, etc. may be mixed.

  Examples of the alkali catalyst used for the synthesis of the water-soluble phenol resin include hydroxides of alkali metals such as LiOH, NaOH, and KOH, and NaOH and KOH are particularly preferable. Moreover, you may mix and use these alkali catalysts.

  The weight average molecular weight (Mw) of the water-soluble phenol resin is preferably 500 or more, more preferably 800 or more, from the viewpoint of improving the mold strength. The weight average molecular weight (Mw) of the water-soluble phenol resin is preferably 8000 or less, and more preferably 5000 or less, from the viewpoint of improving the mold strength. Moreover, the weight average molecular weight (Mw) of the water-soluble phenol resin is preferably 500 to 8000, more preferably 800 to 5000, from the viewpoint of improving the mold strength.

  The content of the water-soluble phenol resin in the binder composition is preferably 20% by mass or more, more preferably 25% by mass or more, and further preferably 30% by mass or more from the viewpoint of improving the mold strength. From the viewpoint of improving workability, the content of the water-soluble phenol resin in the binder composition is preferably 95% by mass or less, more preferably 90% by mass or less, and still more preferably 85% by mass or less. In addition, the content of the water-soluble phenol resin in the binder composition is preferably 20 to 95% by mass, and preferably 25 to 90% by mass from the viewpoint of improving the mold strength and the workability. More preferably, 30-85 mass% is further more preferable.

  As the binder composition as described above, commercially available products are Kao Step SH-8010, SH-8000, S-651, SQ-7000, SL-6000, SL-6070, and S-681. (All made by Kao Quaker).

(Other ingredients)
The binder composition may contain additives such as water, a silane coupling agent, urea, a surfactant, and alcohols to the extent that the effects of the present embodiment are not impaired. In addition, since the final intensity | strength of the casting_mold | template obtained can be improved more when the silane coupling agent is contained in the said binder composition, it is preferable. Examples of the silane coupling agent include N-β- (aminoethyl) -γ-aminopropylmethyldimethoxysilane, N-β- (aminoethyl) -γ-aminopropyltrimethoxysilane, N-β- (amino Ethyl) -γ-aminopropyltriethoxysilane, 3-aminopropyltrimethoxysilane and other aminosilanes, 3-glycidoxypropyltrimethoxysilane, 3-glycidoxypropyltriethoxysilane, 3-glycidoxypropyldimethoxy Examples thereof include epoxy silanes such as methyl silane, 3-glycidoxypropyl methyldiethoxysilane, and 3-glycidoxypropyl triethoxysilane, ureido silane, mercaptosilane, sulfide silane, methacryloxy silane, acryloxy silane, and the like. The content of the silane coupling agent in the binder composition is preferably 0.005 to 3% by mass and more preferably 0.01 to 1% by mass from the viewpoint of improving the mold strength.

  When an additive or the like that does not inhibit the above effect is used, the additive or the like may be added to the refractory particles by either a continuous method or a batch method. Moreover, the method of spraying the said additive etc. and the method of adding quantitatively from a nozzle can be taken.

  The ratio at the time of use of the refractory particles, the binder composition, and the curing agent composition can be set as appropriate, but from the viewpoint of improving the mold strength, the viscosity of the refractory particles is 100 parts by weight. The binder composition is preferably 0.5 parts by mass or more, and more preferably 3 parts by mass or less. From the same viewpoint, the curing agent composition is preferably 20 parts by mass or more, and preferably 30 parts by mass or less with respect to 100 parts by mass of the binder composition.

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

[Curing process]
In the curing step, a known general method can be used as a method of curing the mold composition.

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

<Crucible evaluation>
[Example 1]
[Preparation of binder composition A]
In a 2 liter glass container equipped with a thermometer and a stirrer, 773 g of phenol, 190 g of 48.5 mass% potassium hydroxide aqueous solution and 323 g of water were mixed and heated to 82 ° C. Thereafter, 937 g of a 50% by mass formalin solution was added and reacted at 82 ° C. to obtain a water-soluble phenol resin (phenol-formaldehyde modified resin) having a weight average molecular weight of about 3000. 18.5 parts by mass of water, 3.6 parts by mass of 48.5% by mass potassium hydroxide aqueous solution, 9.5 parts by mass of 48.5% by mass sodium hydroxide aqueous solution with respect to 68.8 parts by mass of the water-soluble phenol resin. Then, 0.8 part by mass of 3-glycidoxypropyltrimethoxysilane (KBM-403, manufactured by Shin-Etsu Chemical Co., Ltd.) was added to obtain a binder composition A.

[Preparation of curing agent composition]
Add a predetermined amount of additive A described in Table 1 to triacetin, cover the sample bottle and store at 35 ° C. for 3 months to obtain a curing agent composition according to Example 1 having the composition described in Table 1. It was.

[Preparation of evaluation sand]
Add 100 parts by mass of binder composition A 1.00 parts by mass and 0.20 parts by mass of the curing agent composition according to Example 1 shown in Table 1 with respect to 100 parts by mass of free mantle (manufactured by Yamakawa Sangyo Co., Ltd.) After kneading and leaving for 1 day, evaluation sand was obtained.

[Evaluation]
40.0 g of evaluation sand according to Example 1 was put into a 45 mm × 36 mm magnetic crucible, covered with a magnetic lid, and heated to 500 ° C. in a small electric furnace KBF794N1 manufactured by Koyo Thermo System Co., Ltd. Was heated for 10 minutes after reaching 500 ° C. The magnetic crucible was taken out from the electric furnace, and the odor before the lid was opened was evaluated by sniffing the odor coming out of the gap between the crucible and the lid within 2 minutes (sensory evaluation 1). Thereafter, the lid was opened 2 minutes after taking out the crucible, and the evaluation was performed by smelling the odor drifting from the evaluation sand in the crucible until 5 minutes after taking out the crucible (sensory evaluation 2). The sensory evaluations 1 and 2 are the relative results of the odor intensity by the four panelists for each sense, and the following evaluations 1 to 5 are evaluated in increments of 0.5. did. The evaluation criteria are as follows.
・ Evaluation 1: Feel extremely strong ・ Evaluation 2: Feel very strong ・ Evaluation 3: Feel strong ・ Evaluation 4: Feel slightly strong ・ Evaluation 5: Feel faint

[Example 2]
It was prepared and evaluated in the same manner as in Example 1 except that the amounts of triacetin and additive A were changed to the amounts shown in Table 1.

Example 3
Evaluation was performed in the same manner as in Example 1 except that the additive was added to the triacetin and the curing agent composition and blended, and immediately after the evaluation sand was prepared.

Example 4
Evaluation was performed in the same manner as in Example 2 except that the additive A was changed to the additive B described in Table 1.

[Comparative Example 1]
Evaluation was performed in the same manner as in Example 1 except that no additive was added to triacetin.

[Comparative Example 2]
Evaluation was performed in the same manner as in Example 3 except that no additive was added to triacetin.

[Comparative Example 3]
A predetermined amount of additive A is added to the binder composition A, the sample bottle is covered, and stored at 35 ° C. for 3 months. The additive composition A is 99.99% by mass, the additive A is 0.00%. A 01% by weight binder composition B was prepared. Evaluation was performed in the same manner as in Example 1 except that the binder composition A was changed to the binder composition B.

[Comparative Example 4]
Evaluation was performed in the same manner as in Comparative Example 3 except that the additive A was not added to the binder composition.

[Comparative Example 5]
Evaluation was conducted in the same manner as in Example 2 except that the additive added to triacetin was changed from additive A to additive C.

  The evaluation results of Examples 1 to 4 and Comparative Examples 1 to 5 are shown in Table 1.

  Examples 1 to 4 in which a mold was produced using a curing agent composition containing additive A or additive B were comparative examples 1 using a curing agent composition containing neither additive A nor additive B. Better results than 2, 4, 5 were shown. From this, it can be seen that the curing agent composition containing additive A and / or additive B can improve the odor during casting.

  Example 2 in which additive A is contained in the curing agent composition showed better results than Comparative Example 3 in which additive A was contained in the binder composition. From this, it can be seen that the additive A and / or the additive B can exhibit the effect more stably when added to the curing agent composition.

<Casting evaluation>
[Examples 5 to 7, Comparative Example 6]
[Preparation of evaluation template]
To 100 parts by mass of Freemantle (Yamakawa Sangyo Co., Ltd. new sand), 1.5 parts by mass of the binder composition described in Table 2 and 0.30 parts by mass of the curing agent composition described in Table 2 were added. An evaluation mold was obtained by kneading, filling into a wooden mold, and removing the mold after curing. Cast iron equivalent to FC250 was poured into the obtained mold at 1370 ° C. The evaluation mold used had an outer shape of 340 mm × 265 mm × 150 mmH, the casting weight was 6 kg, and the S / M (sand metal ratio), which is the ratio of the mold weight to the casting weight, was 3.5. Immediately after pouring, a 900 mm × 900 mm × 900 mmH SUS container was put on, and after 60 minutes, the panel smelled the internal odor and evaluated the impression (sensory evaluation 3). In sensory evaluation 3, odor intensity was relatively compared by sensation by four panelists for each, and the following evaluations 1 to 5 were evaluated in increments of 0.5, and an average value of the evaluation was obtained as an evaluation result. The evaluation results are shown in Table 2. The evaluation criteria are as follows.
・ Evaluation 1: Feel extremely strong ・ Evaluation 2: Feel very strong ・ Evaluation 3: Feel strong ・ Evaluation 4: Feel slightly strong ・ Evaluation 5: Feel faint

Claims (3)

  A curing agent composition for mold making containing dodecahydro-3a, 6,6,9a-tetramethylnaphtho [2,1-b] furan and / or methyldihydrojasmonate.   The hardening | curing agent composition for casting_mold | template shaping | molding of Claim 1 containing an ester compound. A mold forming binder composition containing refractory particles, a water-soluble phenolic resin, a mixing step of mixing the mold molding curing agent composition to obtain a mold composition, and the mold composition as a mold A method for producing a mold having a curing step of filling a frame and curing the mold composition,
The manufacturing method of the casting_mold | template whose said hardening agent composition for mold making is the hardening | curing agent composition for mold making of Claim 1 or 2.