JP2903138B2 - Material for mold - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a mold material used for producing a main mold or a core for casting (hereinafter, referred to as a mold), and particularly to a heat dissipating agent having excellent disintegration properties after casting and a curable binder. The present invention relates to a mold material suitable for producing a mold in which generation of tan due to decomposition is extremely small.

[0002]

2. Description of the Related Art Conventionally, various mold materials have been used for the production of molds. Among them, it is particularly useful for improving the disintegration of molds in casting non-ferrous metals such as aluminum alloys and copper alloys. As a material for a mold, a curable binder having an ethylenically unsaturated group, for example, an ethylenically unsaturated monomer (JP-A-56-109135) is used as a binder for a refractory aggregate represented by silica sand. ), Unsaturated polyester resins (Japanese Patent Application Laid-Open No. 50-104721) or polyfunctional acrylamides (Japanese Patent Application Laid-Open No. 2-802007).

[0003]

However, a mold material using this kind of curable binder has good mold disintegration properties, but the metal generated by the thermal decomposition of the binder is gold. There is a problem that coagulation deposits on the baseboard portion of the mold and the mold cannot be set in the mold. In addition, the composite of the resin and the casting sand adheres to the surface of the mold and forms a depression on the surface of the casting, or adheres to the inner surface of the hollow portion of the casting, causing defective products such as defective sand residue. There is a problem.

Accordingly, an object of the present invention is to provide a mold material, in particular, which is suitable for casting non-ferrous metals, in which the amount of tan generated by the thermal decomposition of the curable binder is reduced without impairing the inherent disintegration of the mold. It is an object of the present invention to provide a mold material used for producing a simple mold.

[0005]

Means for Solving the Problems The inventors of the present invention have made intensive studies to achieve the above object, and as a result, a mold material to which a metal oxide containing a specific element is added has a disintegration property of the mold. It has been found that the deterioration does not occur, and that the generation of rust due to the thermal decomposition of the curable binder is extremely small, and further studies based on this finding have led to the completion of the present invention.

That is, the present invention relates to a refractory aggregate (first component) and a polyolefin having two or more ethylenically unsaturated groups in the molecule.
A mold material comprising a curable binder (second component) containing a functional acrylamide and a third component as essential components, and any of the inorganic compounds listed below as the third component It is a material for a mold characterized by using the above.

[0007] The first is a metal oxide containing one element selected from the group consisting of cobalt, nickel, copper and zinc in the molecule.

[0008] A second aspect is a mixture of the metal oxide and the iron oxide according to the first aspect.

Thirdly, it is composed of any one of the metal oxides or iron oxides described in the first aspect and a metal carbonate and / or a metal acetate, and the content of the metal carbonate and / or the metal acetate is reduced. A mixture that is no more than 20% by weight.

[0010] Fourth, the metal oxide, iron oxide, metal carbonate and / or metal acetate according to the first aspect, and the content of the metal carbonate and / or metal acetate is 20% by weight or less. Some mixture.

In the present invention, the refractory aggregate used as the first component is a refractory sandy substance which functions as a base of a mold. For example, in addition to commonly used silica sand, olivine sand, zircon Sand, chromite sand, special sand such as alumina sand, ferrochrome-based slag, ferronickel-based slag, slag-based particles such as converter slag, porous particles such as nigai cera beads, and regenerated particles thereof. However, the present invention is not limited to this. These may be used alone or in combination of two or more.

[0012] In the present invention, the polyfunctional having two or more ethylenically unsaturated groups in the molecule used as the second component
Curable binder containing reactive acrylamides (hereinafter, referred to as
The "curable binder") is capable of exhibiting curability based on a polymerization reaction of an ethylenically unsaturated group at room temperature or under heating in the presence or absence of a polymerization accelerator to bind refractory aggregate. And a binder having a function of shaping into a predetermined mold shape . The amount of the curable binder used is not specifically limited because it varies depending on the mold making method, mold characteristics, and the like. Generally, however, 0.1 to 0.1 part by weight of the refractory aggregate is used.
The amount is preferably 10 to 10 parts by weight, and more preferably 0.1 to 5 parts by weight.

[0013] The take polyfunctional acrylamides, such as described in detail below, but is intended to mean a liquid or solid acrylamide compound having two or more ethylenically unsaturated groups in the molecule, Among them, preferably,
These are solid polyfunctional acrylamides that exhibit extremely excellent low-temperature curability in the shell mold method.

[0014] The liquid polyfunctional acrylamides, cold self hard method is suitable for the production of the mold material Shimetai applied to ventilation curing method or warm or hot box method, specifically, For example, glycerin bis (N-methylene acrylamide), glycerin tris (N-methylene acrylamide), diethylene glycol bis (N
-Methyleneacrylamide) and the like, but are not limited thereto. These may be used alone or in combination of two or more. On the other hand, solid polyfunctional acrylamides are suitable for producing a dry mold material mainly applied to a shell mold method,
Specifically, for example, methylenebisacrylamide, ethylenebisacrylamide, methylenebismethacrylamide, oxydimethylenebisacrylamide, ethylenedioxybis (N-methyleneacrylamide), hexanedioxybis (N-methyleneacrylamide), p-
Xylene dioxybis (N-methylene acrylamide)
And the like, but are not limited to these. These may be used alone or in combination of two or more. Among them, those containing at least one of solid polyfunctional acrylamides represented by the following formulas (I) to (IV) are preferred in view of ease of production and cost, moisture absorption resistance of a mold material and physical properties. Is preferably used.

[0015]

Embedded image

(In these formulas, R is each independently hydrogen or an alkyl group having 1 to 5 carbon atoms, and n is 2
6 to an integer. )

[0017] Incidentally, the solid polyfunctional acrylamides, as needed, for example, acrylamide, N-
Methylol acrylamide, acrylic acid, methacryl
Acid, 1,6-hexanediol diacrylate, trime
Ethylenic unsaturation such as tyrolpropane triacrylate
Curable binders can be used in combination with sum monomers, diallyl phthalate, unsaturated polyester resins or liquid polyfunctional acrylamides. In view of the above, the proportion of the solid polyfunctional acrylamide in the curable binder is 50%.
% By weight, preferably 70% by weight or more, more preferably 90% by weight or more.

In connection with the solid polyfunctional acrylamides, a combination of at least one of a saturated amide compound, a solid alcohol and a silane coupling agent is useful for improving the strength of the mold. When used in combination with a thermoplastic resin in the form or solution, it is useful for improving the properties of the mold material (free flowing property, blocking resistance, moisture absorption resistance) and preventing deterioration of the mold strength.

The above-mentioned saturated amide compound and solid alcohols function to lower the melt viscosity of the solid polyfunctional acrylamide upon heating, thereby improving the coating property on the refractory aggregate, Suitable examples of such a saturated amide compound include, for example, acetic acid amide, dimethylacetamide, acetoanilide, acetoacetic anilide, acetoacetic xylide, acetoacetic toluidide, N-methylbenzamide, benzamide, propionamide, N-phenylpropionamide , Ε-
Examples include, but are not limited to, caprolactam, formamide, dimethylformamide, and the like. Among them, acetic acid amide, acetanilide, and acetoacetic anilide are particularly preferable. Examples of suitable solid alcohols include, but are not limited to, 1,6-hexanediol, trimethylolpropane, para-xylene glycol, carbitol, and the like. Each of these saturated amide compounds and solid alcohols may be used alone or in combination of two or more. It is preferably 20 to 20 parts by weight, and more preferably 0.1 to 10 parts by weight. This usage amount is 0.
If the amount is less than 01 parts by weight, the effect of improving the strength of the mold is hardly obtained, and if it exceeds 20 parts by weight, the curing speed is apt to deteriorate, which is not preferable.

The silane coupling agent has a function of increasing the strength of the template by a well-known coupling action. Specifically, for example, vinyltrimethoxysilane, vinyltris (β-methoxy) silane, vinyltris (Β-methoxyethoxy) silane, γ-glycidoxypropyltrimethoxysilane, β- (3,4-epoxycyclohexyl) ethyltrimethoxysilane, N
-Β (aminoethyl) γ-aminopropyltrimethoxysilane, γ-aminopropyltriethoxysilane, and the like, but are not limited thereto. These may be used alone or in combination of two or more. Among them, vinyl silane is particularly preferable. The amount of the silane coupling agent used is preferably 0.01 to 10 parts by weight, and more preferably 0.1 to 5 parts by weight, based on 100 parts by weight of the curable binder. If the amount is less than 0.01 part by weight, the effect of improving the mold strength is hardly obtained, and if it exceeds 10 parts by weight, the effect of improvement is hardly changed and is not economically preferable.

The above-mentioned thermoplastic resin further covers the binder layer on the surface of the refractory aggregate to prevent the outside air and to prevent the binder layer from peeling off, and to provide the mold with its own self-lubricating property. It functions to impart lubricity to materials for use, and preferred examples of such a thermoplastic resin include, for example, vinyl acetate resin, ethylene-vinyl acetate copolymer resin, methacrylate resin, ethylene methacrylate Examples include, but are not limited to, ester copolymer resins, polystyrene resins, polyethylene resins, polybutyral resins, and the like. Among them, a vinyl acetate resin, particularly a vinyl acetate resin, is particularly preferable. These may be used alone or in combination of two or more, and the amount used is 1 to 20 parts by weight, preferably 2 to 10 parts by weight, per 100 parts by weight of the curable binder. Parts by weight. If the amount is less than 1 part by weight, the effect of improving the properties of the mold material and the effect of preventing the deterioration of the mold strength cannot be obtained, and if it exceeds 20 parts by weight, the curing speed tends to deteriorate, which is not preferable.

The above-mentioned polyfunctional acrylamides are used in the reaction modes listed below, for example, acrylamides such as acrylamide and methacrylamide, and N-methylolacrylamides such as N-methylolacrylamide and N-methylolmethacrylamide. And / or N
Reaction with N-alkoxymethylacrylamides such as -methoxymethylacrylamide, N-methoxymethylmethacrylamide, N-methylolacrylamide itself, or reaction of N-methylolacrylamide with N-alkoxymethylacrylamide, N-methylol Acrylamides and ethylene glycol, diethylene glycol, glycerin, 1,6-hexanediol,
Reaction with polyols such as trimethylolpropane,
It can be produced by reacting acrylamides with aldehydes such as formaldehyde and glyoxal. Usually, these reactions are carried out at a temperature of 30 to 100 ° C. for about 1 to 24 hours in the presence of an acid catalyst and a polymerization inhibitor. Preferably, water and alcohols generated are removed from the reaction system, and air is removed. And / or depressurizing operation while suppressing thermal polymerization.

The curable binder in the present invention can be crosslinked and cured simply by heating. However, in the case of performing more rapid heat curing or curing at room temperature, it is generally known. In particular, a radical polymerization initiator or a combination system of a radical polymerization initiator and a redox catalyst is preferably used. The radical polymerization initiator is not particularly limited, and may be, for example, azobisisobutyronitrile, benzoyl peroxide, methyl ethyl ketone peroxide, acetyl peroxide, t-butyl hydroperoxide, di-t-butyl peroxide, cumene hydroperoxide. Peroxide, dicumyl peroxide, t-
Butyl perbenzoate, p-chlorobenzoyl peroxide, cyclohexanone peroxide, potassium persulfate, ammonium persulfate, hydrogen peroxide and the like.
Among them, an organic radical polymerization initiator is particularly preferable. On the other hand, examples of the redox catalyst include, but are not limited to, sodium bisulfite, sodium formaldehyde sulfoxylate, cobalt octenoate, cobalt naphthenate, dimethylaniline, triethylamine, mercaptan, and the like. These radical polymerization initiators and redox catalysts may be used alone or in combination of two or more. The amount of the polymerization accelerator used is not specifically limited because it varies depending on the type of the curable binder, the curing method, and the like, but is generally 0.001 to 50 parts by weight based on 100 parts by weight of the curable binder. Used in the range.

The third component used in the present invention is an inorganic compound having a function of suppressing the generation of tar due to the thermal decomposition of the curable binder, one of which is cobalt or nickel in the molecule. Oxide containing any one element of, copper and zinc (hereinafter referred to as "specific metal oxides")
It is. Preferred examples of such specific metal oxides include, for example, cobaltous oxide, cobaltic oxide, nickelous oxide, cuprous oxide, cupric oxide, zinc oxide and mixtures thereof. However, the present invention is not limited to these. Among them, cupric oxide and nickel nickel oxide are particularly preferred.

The two are combinations which exhibit a better effect of reducing tan than the above-mentioned specific metal oxides, and include a mixture of a specific metal oxide and iron oxide, and a specific metal oxide, iron oxide and metal carbonate. A mixture with a salt and / or a metal acetate (hereinafter referred to as “metal carbonate or the like”), a mixture of specific metal oxides and a metal carbonate or the like, or a mixture of iron oxide and a metal carbonate or the like. Among them, preferred is a mixture of specific metal oxides and iron oxide, or a mixture of specific metal oxides, iron oxide and metal carbonate, and more preferably specific metal oxides, iron oxide and metal carbonate. Mixtures such as salts, especially mixtures of cupric oxide, ferric oxide and metal carbonates are preferred. In the various mixtures, the mixing ratio of the specific metal oxides and the iron oxide is arbitrary, but the ratio of the metal carbonate or the like in the mixture (third component) is 20 wt. % Or less.

Preferred examples of the above iron oxide include, for example,
Examples include ferrous oxide and ferric oxide, but are not limited thereto. Preferable examples of the metal carbonate and the like include manganese carbonate, cobaltous carbonate, nickelous carbonate, cupric carbonate, zinc carbonate, manganese acetate, cobaltous acetate, nickelous acetate, manganese acetate. Examples include but are not limited to copper, zinc acetate and the like.
These iron oxides and metal carbonates may be used alone or in combination of two or more. In addition,
The amount of the above-mentioned third component used may be curable binder 10
10 parts by weight or more based on 0 parts by weight is preferable, and preferably 2 parts by weight.
It is used in the range of 0 to 500 parts by weight. If the amount of the third component is less than 10 parts by weight, the effect of reducing the dent is small and not practical.

In the mold material of the present invention, in addition to the above-mentioned components, various additives such as stearic acid amide, methylol stearic acid amide, ethylenebisstearic acid amide, calcium stearate, carnauba wax may be used. And the like, a deodorant such as a stop order, an epoxy compound, a melamine compound, a urea-based compound and the like, or a reaction product between them or between these and acrylamides.

The material for a mold of the present invention may be appropriately selected from coating methods generally used in the art, for example, a hot marling method, a semi-hot marling method, and a cold marling method according to the purpose. Can be manufactured by In particular, when a solid polyfunctional acrylamide is used as a curable binder, it has a feature that a cold marling method can provide a mold material that is comparable to a hot marling method, and simplifies manufacturing equipment. And it is useful in terms of reduction of energy cost.

The material for a mold of the present invention thus obtained is
The mold can be formed according to a conventionally known mold molding method, for example, a heat curing method such as a shell mold method or a warm or hot box method, or a room temperature curing method such as a room temperature self-curing method or a ventilation curing method. In addition, the resulting mold is excellent in disintegration after casting and the amount of generated tan is extremely small.Therefore, in the casting field where such properties are required, particularly for casting of non-ferrous metals such as aluminum alloys and copper alloys. Extremely useful.

[0030]

EXAMPLES Hereinafter, the present invention will be described specifically with reference to Examples, but the present invention is not limited to these Examples. In addition, the obtained mold material was measured for bending strength or compressive strength according to the following test method according to the disintegration of the mold, the amount of generated tan, and the mold making method.

Disintegration of mold: First, a dog bone type disintegration test core 1 as shown in FIG.
(25 mm thick × 40 mm wide × 75 mm long) and a main mold 2 (75 mm thick × 80 mm wide × 125 mm long) having a space slightly larger than the core 1 using an organic self-hardening mold material. . Next, after the core 1 was set in the main mold 2, an aluminum alloy solution having a temperature of 720 ° C. was poured into the core 1 and allowed to cool to room temperature to produce an aluminum casting 3 as shown in FIG. 2. Next, the casting 3 was vibrated for 3 seconds with an air hammer having a pressure of 0.5 kgf / cm ^{2, and} the collapsed core sand was taken out from the discharge port 4 having a diameter of 16 mm, and its weight was measured. This series of operations was repeated until the core sand was completely discharged from the casting 3. The disintegration of the mold is expressed as a percentage obtained by dividing the weight of the core sand discharged by the vibration for 3 seconds by the total weight of the core sand discharged, and the cumulative total of the core sand completely discharged is shown. Disintegration was evaluated by shaking time.

Amount of tan: 20 g of mold material 9 is placed in a glass test tube (inner diameter 16 mm × length 180 mm) 8 shown in FIG. 3, and then a pre-weighed aluminum foil ( 10 was attached, and finally a silicone rubber 11 provided with a glass tube (inner diameter 6 mm × length 180 mm) 12 was attached to prepare a tar measuring instrument. Then, as shown in FIG. 3, within the tubular furnace 7 held in 600 ° C. taken out after曝熱between installed to 7 minutes the tar instrument, then allowed to cool to room temperature, the aluminum foil from tar instrument 1
0 was taken out and its weight was measured. Generated amount of tar (ppm
/ Material for mold) was calculated by the following equation.

[0033]

(Equation 1)

Bending strength: a bending test piece maintained at a predetermined temperature (thickness 25.4 mm × width 25.4 mm × length 120 m)
m) The mold material was blow-filled into the mold at a pressure of 4 kgf / cm ² , baked for 1 minute, removed from the mold, allowed to cool to room temperature, and measured with a JACT bending force tester.

Compressive strength: A mold material immediately after kneading is hand-filled and filled in a wooden mold for preparing a compression test piece having a plurality of cavities (diameter 50 mm × height 50 mm), and is left at room temperature for a predetermined time ( Every 1, 3, 24 hours), the sample was removed from the mold and measured with an anti-pressure tester manufactured by Takachiho Seiki.

REFERENCE EXAMPLE 1 N-methylacrylacrylamide was placed in a reaction vessel capable of blowing under reduced pressure and air at 218.
g, 61 g of acrylamide, 15 g of 92% by weight paraformaldehyde, 2.8 g of oxalic acid, and 1 × 10 ^-2 g of hydroquinone, and stirred and mixed. The pressure inside the reaction vessel was reduced, and air blowing was started to 70 ° C. Heat up,
The reaction was completed by aging at the same temperature for 6 hours while removing generated water out of the reaction system. The obtained curable binder A was a powder mainly composed of oxydimethylenebisacrylamide and methylenebisacrylamide.

Reference Example 2 In the reaction vessel used in Reference Example 1, 303 g of N-methylacrylacrylamide, 92 g of glycerin, 2.2 g of oxalic acid and 1 g of hydroquinone were added.
× 10 ^-2 g were charged and mixed by stirring. The pressure in the reaction vessel was reduced, and the temperature was raised to 60 ° C. by blowing air, and aged at the same temperature for 6 hours while removing generated water outside the reaction system. The reaction was completed. Thereafter, the mixture was cooled to room temperature, and 1% by weight of a vinyl silane coupling agent (A-172, manufactured by Nippon Unicar Co., Ltd.) was added to obtain a liquid curable binder B. The obtained curable binder B was mainly composed of glycerin tris (N-methyleneacrylamide).

Example 1 and Comparative Example 1 In a Whirl mixer made by Enshu Tekko, 5 kg of room temperature freemantle sand was used as a first component, and a 60% by weight methyl ethyl ketone peroxide solution (hereinafter referred to as "MEKPO") was used as a polymerization accelerator. ) And silane coupling agent A-1 as an additive
72 g, 60 g of the powdery curable binder A prepared in Reference Example 1 as the second component, and 30 g of cupric oxide as the third component, and then kneaded for 180 seconds to obtain a free flowing property. A rich dry mold material (Example 1) was obtained. Further, for comparison, a mold material for comparison (Comparative Example 1) was obtained in the same manner as in Example 1 except that the third component was not used.

[0039]

Example 2 In a Whirl mixer manufactured by Enshu Tekko, 5 kg of room temperature freemantle sand was used as a first component, and 60% by weight was used as a polymerization accelerator.
3 g of MEKPO and 0.1 g of benzoyl peroxide.
6 g, 3 g of acetanilide as an additive, 0.6 g of carnauba wax and silane coupling agent A-172
, 0.6 g of the powdery curable binder A prepared in Reference Example 1 as the second component, and 42 g of nickel oxide as the third component, and then kneaded for 180 seconds to form a free-flowing dry state. (Example 2 ) was obtained.

[0041] In Example 3-8] In Example 2, except for changing the third component in the blending composition shown in Table 2, mold Inuitai rich in free-flowing six in the same manner as in Example 2 Materials for use (Examples 3 to 8 ) were obtained.

Next, the bending strength, the disintegration of the mold and the amount of generation of the dies were measured for the mold materials obtained in the above Examples and Comparative Examples according to the above-mentioned test methods, and the results were shown in Tables 1 and 2. It is shown in FIG.

[0043]

[Table 1]

[0044]

[Table 2]

As is clear from Tables 1 and 2, the following items were confirmed for the mold material of the present invention. The amount of generated tan is significantly reduced as compared with the conventional example (Comparative Example 1 ) in which the inherent disintegration of the mold is maintained and the third component is not used.

A mixture of specific metal oxides and any one of iron oxide or metal carbonate, a mixture of iron oxide and metal carbonate, or a specific metal oxide, iron oxide and metal carbonate (Examples 3 to 6 ) can further reduce the amount of generated tan in the case of using the specific metal oxides alone (Example 2 ).

The amount of the third component used was determined in Example 7.
From the results of and 8 , it is found that when the content is less than 10% by weight, the effect of reducing tar is small.

[0048]

Example 9 , Comparative Example 2 In a Shinagawa tabletop mixer, 2 kg of room temperature freemantle sand as the first component, and 30 g of the liquid curable binder B prepared in Reference Example 2 as the second component , 10 as a polymerization accelerator
15 g of a 5% by weight benzoyl peroxide acetone solution, 6 g of a 5% by weight dimethylaniline acetone solution and 15 g of cupric oxide as a third component were charged and kneaded for 60 seconds to obtain a wet mold material. For comparison, a wet comparative mold material (Comparative Example 2 ) was obtained in the same manner as in Example 9 except that the third component was not used.

Next, the compressive strength, the mold disintegration property and the amount of generation of tar of the mold material obtained in Example 9 and Comparative Example 2 were measured in accordance with the above-mentioned test methods. Table 3 shows the results. As a result, the mold material of the present invention (Example 9 ) maintains the disintegration property of the original mold, and has a significantly reduced amount of tan as compared with the conventional example (Comparative Example 2 ) in which the third component is not used. It was confirmed that.

[0051]

[Table 3]

[0052]

As described above, according to the mold material of the present invention, in the casting of non-ferrous metals, the amount of generation of tan is greatly reduced as compared with the prior art, without impairing the collapsibility of the original mold. can do. Therefore, it is possible to eliminate a decrease in production efficiency due to a defective setting of a mold or a defective casting product.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view showing a state where a core is set on a main die.

FIG. 2 is a longitudinal sectional view showing a state of a test casting for measuring the disintegration of a mold after casting.

FIG. 3 is a vertical cross-sectional view of a main part showing a measurement state of a generation amount of tan.

[Description of Signs] 1 ... Core 2 ... Main mold 3 ... Aluminum casting 4 ... Core sand discharge port 5 ... Pouring port 6 ... Vibration position by air hammer 7 ... Tube heating furnace 8 ... Glass test tube 9 ... Mold Material 10 ... Aluminum foil 11 ... Silicon rubber 12 ... Glass tube

──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Goro Kakinuma 26-4 Niitsu, Minamiyama surname, Fuso-cho, Niwa-gun, Aichi Prefecture Inside the Aichi Plant of Asahi Organic Materials Industry Co., Ltd. (72) Inventor Susumu Seki Oguro, Tsurumi-ku, Yokohama-shi, Kanagawa No. 10-cho, Nitto Chemical Industry Co., Ltd. (72) Inventor Norimasa Yoshida 10-1, Oguro-cho, Tsurumi-ku, Yokohama-shi, Kanagawa Prefecture Nitto Chemical Industry Co., Ltd. (56) References JP-A-55-55 149745 (JP, A) (58) Fields investigated (Int. Cl. ⁶ , DB name) B22C 1/00-1/26

Claims (5)

(57) [Claims] 1. A polyfunctional acrylamide having a refractory aggregate (first component) and two or more ethylenically unsaturated groups in a molecule.
A mold material containing a curable binder (second component) containing a metal and a third component as essential components,
A material for a mold, characterized in that the component is a metal oxide containing one element selected from the group consisting of cobalt, nickel, copper and zinc in the molecule. 2. The method according to claim 1, wherein the third component is in a molecule.
One kind selected from the group of baltic, nickel, copper and zinc
Wherein a mixture of iron oxide metal oxide including the element
Item 7. The mold material according to Item 1 . 3. The method according to claim 1, wherein the third component is co-incorporated in the molecule.
One kind selected from the group of baltic, nickel, copper and zinc
2. The composition according to claim 1, comprising a mixture of a metal oxide having an element and a metal carbonate and / or metal acetate, wherein the content of the metal carbonate and / or metal acetate is 20% by weight or less.
The material for the mold according to the above . 4. The method according to claim 1, wherein the third component is in a molecule.
One kind selected from the group of baltic, nickel, copper and zinc
Consist of a mixture of a metal oxide and iron oxide and the metal carbonate and / or metal acetate salts with elements, and the content of the carbon acid metal salts and / or metal acetate is 20 wt% or less 請
The material for a mold according to claim 1 . 5. The third component according to claim 1, comprising a mixture of iron oxide and a metal carbonate and / or metal acetate, wherein the content of the metal carbonate and / or metal acetate is 20% by weight. mold material according to claim 1 or less%.