JP6739973B2 - Method for manufacturing structure for casting production - Google Patents

Description

The present invention is a method for producing a structure for producing a casting such as a mold used during production of a casting, an additive for producing a structure slurry composition for producing a casting, a method for producing a casting, and a slurry composition for a structure for casting casting. Manufacturing method.

For casting, generally, a mold having a cavity inside is formed from foundry sand based on a wooden mold or a metal mold, and after arranging a core in the cavity as necessary, a molten metal is supplied to the cavity. Is being manufactured.

The manufacturing of wooden molds and dies requires skill and expensive equipment for processing, and is disadvantageous in that they are expensive and heavy, and also causes a problem of waste treatment, and is difficult to use in addition to mass-produced castings. Further, in the sand mold using foundry sand, a binder is added to ordinary sand and the binder is hardened to maintain its shape. Therefore, a recycling process is essential for reusing sand. There is also a problem that waste such as dust is generated during the recycling process. In addition, when the core is manufactured in a sand mold, it is difficult to handle due to the weight of the core itself in addition to the above problem, and further, strength retention during casting and core removability after casting, which are conflicting performances. Is required.

As a technique for solving such a problem, there is known a structure in which a member used in a mold is molded mainly with organic fibers, inorganic fibers and thermosetting resin. And it is known to manufacture such a structure using the raw material slurry containing the said component.

For example, in Patent Document 1, a structure for casting production, which contains an organic fiber, an inorganic fiber, and a thermosetting resin, has good moldability of the casting production structure, is lightweight, and has sufficient hot strength at the time of casting. It is disclosed that the obtained casting has excellent shape retention and surface smoothness, and further has excellent removability after casting.

Further, Patent Document 2 discloses a casting manufacturing structure containing organic fibers, carbon fibers, inorganic particles, and at least one thermosetting resin selected from the group consisting of phenol resins, epoxy resins and furan resins. The structure for casting production has good moldability, is lightweight, has sufficient hot strength and shape retention even during casting, and is excellent in shape retention and surface smoothness of the resulting casting. It is disclosed that the removability is excellent.

Further, Patent Document 3 includes a structure (I) containing organic fibers, inorganic fibers and a binder, and inorganic particles having an average particle diameter of 1 to 800 nm attached to the surface of the structure (I). It is disclosed that the foundry structures constructed can ameliorate gas defects that are casting quality.

Further, in Patent Document 4, a step (I) of obtaining a slurry composition containing an organic fiber, an inorganic fiber, a thermosetting resin and water, a step (II) of forming the slurry composition into a fiber laminate, and A method for producing a structure for producing a casting, comprising a step (III) of dehydrating and drying the fiber laminate, wherein the step (I) is carried out by a predetermined method, and an average fiber of inorganic fibers in the structure for producing a casting. A casting having a length of 1 mm or more and 5 mm or less, which is excellent in surface smoothness and strength of the casting manufacturing structure, has a small amount of heat shrinkage, and is excellent in seizure resistance of the resulting casting by the method for manufacturing a casting manufacturing structure. It is disclosed that a manufacturing structure can be provided.

JP 2004-181472 A JP, 2005-349428, A JP, 2007-21578, A International Patent Publication No. 2014/104045

Inorganic fibers are used for the purpose of forming the skeleton of the structure for casting production and maintaining the shape after casting, but it has been found that the raw material slurry using this tends to cause lumps.
When a structure for casting production is manufactured using a raw material slurry containing inorganic fibers, it is desirable to use a slurry with less lumps to improve the quality of castings manufactured from the structure.

The present invention provides a method for producing a casting production structure, which can obtain a casting production structure capable of producing a high quality casting with less generation of lumps in the raw material slurry.

The present invention comprises a step (I) of obtaining a slurry composition containing organic fiber, inorganic fiber, inorganic particles, thermosetting resin, a surfactant having cationic nitrogen or a polymer having cationic nitrogen, and water. The present invention relates to a method for producing a structure for producing castings, including a step (II) of forming a slurry composition into a fiber laminate to obtain a fiber laminate, and a step (III) of dehydrating and drying the fiber laminate.

Further, the present invention is a structure slurry for casting production, comprising organic fiber, inorganic fiber, inorganic particles, thermosetting resin, and water, which comprises a surfactant having cationic nitrogen or a polymer having cationic nitrogen and water. It relates to an additive for producing a composition.

The present invention also relates to a casting manufacturing method using the casting manufacturing structure obtained by the above-described casting manufacturing structure manufacturing method of the present invention.

Further, the present invention is a step (I) of obtaining a slurry composition containing organic fibers, inorganic fibers, inorganic particles, thermosetting resin, a surfactant having cationic nitrogen or a polymer having cationic nitrogen, and water. And a method for producing a slurry for a structure for producing a casting, the method including:

According to the method for producing a casting production structure of the present invention, it is possible to obtain a casting production structure in which lumps of the raw material slurry are less likely to occur and a high quality casting can be produced. The casting production structure produced by the present invention is suitable for casting under high pressure and casting with a large casting mass.

In the present invention, by obtaining a slurry composition containing a surfactant having a cationic nitrogen or a polymer having a cationic nitrogen in the step (I), the occurrence of lumps in the raw material slurry is small and a good quality casting is produced. A castable structure that can be obtained is obtained.
Further, in the present invention, in the step (I), it is preferable to mix water with a surfactant having cationic nitrogen or a polymer having cationic nitrogen, and then to mix inorganic fibers to obtain the slurry composition. When these are satisfied, a better damaging effect can be obtained. The reason for producing such an effect is not clear, but it is considered as follows.
In the step (I), a surfactant having a cationic nitrogen or a polymer having a cationic nitrogen is added to the beating mixture before the inorganic fiber so that the surface charge of the negatively charged organic fiber is absorbed. Soft floc can be formed. By adding the inorganic fibers thereto, the inorganic fibers are easily supported by the flocs. It is considered that by doing so, the aggregation of the inorganic fibers is suppressed and the occurrence of lumps is reduced.
Further, when an anionic compound is added, it is considered that neutralization aggregation occurs, hard flocs are formed, and aggregation of the inorganic fibers is further suppressed.

The casting manufacturing structure manufactured by the manufacturing method of the present invention will be described below.
<Structure for casting production>
The casting manufacturing structure produced according to the present invention contains organic fibers, inorganic fibers, inorganic particles, a thermosetting resin, and a surfactant having cationic nitrogen or a polymer having cationic nitrogen. Hereinafter, the organic fiber, the inorganic fiber, the inorganic particles, the thermosetting resin, and the surfactant having cationic nitrogen or the polymer having cationic nitrogen will be described. However, the matters described below are the steps (I) and (II ) And (III), the organic fiber, the inorganic fiber, the inorganic particles, the thermosetting resin, and the surfactant having cationic nitrogen or the polymer having cationic nitrogen can also be applied.

(I) Organic fibers Organic fibers form a skeleton in a state before being used for casting in a structure for casting production, and part or all of them burn by the heat of molten metal during casting, and castings after casting Voids are formed inside the manufacturing structure.

From the viewpoint of moldability, the organic fiber is preferably a paper fiber, a fibrillated synthetic fiber, a recycled fiber (for example, rayon fiber), or the like, and these are used alone or in combination of two or more kinds. Among these, paper fibers are preferable from the viewpoints of improving moldability of the structure for casting production, dehydration, viewpoint of excellent wet strength properties of dried molded bodies and availability, supply stability, and economical efficiency. preferable. As the paper fiber, wood pulp, cotton pulp, linter pulp, bamboo, straw or other non-wood pulp can be used. As the paper fiber, virgin pulp or waste paper pulp (recovered product) may be used alone or in combination of two or more. As the organic fiber, it is more preferable to use waste paper pulp (newspaper, etc.) from the viewpoints of improving the moldability of the structure for casting production, supplyability, economy and environmental protection.

The average fiber length of the organic fibers is preferably 0.8 mm or more, more preferably 0.9 mm or more, from the viewpoint of improving the strength of the casting manufacturing structure, and preferably 2 mm or less, from the viewpoint of improving the surface smoothness of the casting manufacturing structure. 1.8 mm or less is more preferable, and 1.5 mm or less is further preferable.

From the viewpoint of improving the moldability of the casting manufacturing structure, the content of the organic fibers in the casting manufacturing structure is preferably 1 part by mass or more, and 5 parts by mass or more with respect to 100 parts by mass of the casting manufacturing structure. More preferably, 10 parts by mass or more, still more preferably 20 parts by mass or more, further preferably 40 parts by mass or less, with respect to 100 parts by mass of the casting manufacturing structure, from the viewpoint of suppressing gas generation during casting. It is more preferably not more than mass parts.
The content of each component in the casting manufacturing structure is similar to the charging amount in the slurry composition for the casting manufacturing structure used in the present invention, the charging amount in the casting manufacturing structure The content of each component may be used. For example, parts by mass with respect to 100 parts by mass of the slurry raw material, which will be described later, may be used as the content of each component in the structure for casting production.

(Ii) Inorganic fiber Inorganic fiber forms its skeleton in a state before being mainly used for casting in a structure for casting production, and maintains its shape without being burned by heat of molten metal during casting. In particular, when the thermosetting resin described below is used, the inorganic fiber can suppress the thermal contraction caused by the thermal decomposition of the thermosetting resin due to the heat of the molten metal.

Examples of the inorganic fibers include carbon fibers, artificial mineral fibers such as rock wool, ceramic fibers, natural mineral fibers, glass fibers, silica fibers, and metal fibers. These inorganic fibers can use 1 type(s) or 2 or more types. Among these, carbon fibers having high strength even at a high temperature at which a metal melts are preferable from the viewpoint of suppressing heat shrinkage during casting. Of these, pitch-based or polyacrylonitrile (PAN)-derived carbon fibers are preferably used, and PAN-based carbon fibers are more preferable.

The average fiber length of the inorganic fibers, preferably carbon fibers, in the structure for casting production is 1 mm or more from the viewpoint of improving the strength of the structure for casting production, suppressing heat shrinkage and preventing seizure of the casting. Is preferably 2 mm or more, more preferably 5 mm or less, and more preferably 4 mm or less, from the viewpoint of improving the strength of the structure for producing a casting and preventing seizure of the casting. Here, the average fiber length of the inorganic fibers in the structure for casting production was measured by observing the fiber length of the inorganic fibers present on the surface of the structure for casting production, and measuring 50 fiber lengths per 1 cm ² . It can be an average value. The fiber length can be measured via a magnifying means such as a microscope. In the examples, the average fiber length of the inorganic fibers in the structure is measured by this method.

The content of the inorganic fibers, preferably carbon fibers, in the structure for casting production is 100 parts by mass of the structure for casting production, the strength of the structure for production of casting is improved, the heat shrinkage is suppressed, and the seizure resistance. From the viewpoint of improvement, 1 part by mass or more is preferable, 2 parts by mass or more is more preferable, 3 parts by mass or more is further preferable, generation of lumps at the time of slurry preparation in the step (I) is suppressed, and a structure for casting production is obtained. From the viewpoint of improving the surface smoothness, it is preferably 10 parts by mass or less, more preferably 9 parts by mass or less, and further preferably 8 parts by mass or less.

The mass ratio of the organic fiber and the inorganic fiber, preferably the mass ratio of the organic fiber and the carbon fiber, is inorganic fiber/organic fiber, and further carbon fiber/organic fiber, which improves the strength of the structure for casting production, suppresses heat shrinkage, and From the viewpoint of improving seizure resistance, 0.05 or more is preferable, 0.1 or more is more preferable, 0.12 or more is further preferable, 0.15 or more is further preferable, and lump formation prevention of the structure for casting production is prevented. From the viewpoint of improving surface smoothness, moldability and strength, 1.0 or less is preferable, and 0.5 or less is more preferable.

In addition, the long axis/minor axis ratio of the inorganic fibers, preferably carbon fibers, in the structure for producing castings is from the viewpoint of improving the strength of the structure for producing castings, the viewpoint of improving the moldability of the structure for producing castings, and the castings. From the viewpoint of suppressing heat shrinkage of the manufacturing structure, it is preferably 1 or more, more preferably 10 or more, still more preferably 50 or more, and preferably 5000 or less, more preferably 2000 or less, still more preferably 1000 or less. is there.

(Iii) Inorganic particles From the viewpoint of fire resistance, inorganic particles are preferably aggregate particles of refractory materials such as obsidian, graphite, mica, silica, hollow ceramics and fly ash. Of these, obsidian is more preferable. The inorganic particles may be used alone or in combination of two or more. The hollow ceramics are hollow particles contained in fly ash, and can be obtained by floating and sorting fly ash with water.

The average particle diameter of the inorganic particles is preferably 10 μm or more, more preferably 20 μm or more, from the viewpoint of improving the moldability of the structure for producing a casting, and from the same viewpoint, 60 μm or less is preferable, and 40 μm or less is more preferable.

The average particle diameter of the inorganic particles is less than 200 μm when the average particle diameter determined by the first measurement method is 200 μm or more, and when the average particle diameter determined by the following first measurement method is 200 μm. In this case, it can be determined by measuring with the second measuring method described below.

[First measuring method]
JIS Z2601 (1993) "Testing method for foundry sand" Measured according to the method specified in Annex 2, and 50% by mass is taken as the average particle diameter. The mass accumulation is calculated by regarding the particles on each sieving surface as the “average diameter Dn (mm)” shown in Table 2 of JIS Z2601 (1993).

[Second measuring method]

It is an average particle diameter of 50% in volume cumulative measured by using a laser diffraction type particle size distribution measuring device (LA-920 manufactured by Horiba, Ltd.). The analysis conditions are as follows.
・Measurement method: Flow method ・Refractive index: Depends on various inorganic particles (see manual attached to LA-920)
・Dispersion medium: use one suitable for various inorganic particles ・Dispersion method: stirring, built-in ultrasonic wave (22.5 kHz) 3 minutes ・Sample concentration: 2 mg/100 cm ³

The content of the inorganic particles in the casting manufacturing structure is preferably 10 parts by mass or more with respect to 100 parts by mass of the casting manufacturing structure, from the viewpoint of improving the hot strength during casting of the casting manufacturing structure. 20 mass parts or more is more preferable, 40 mass parts or more is still more preferable, from the viewpoint of improving the strength of the structure for casting production, 80 mass parts or less is preferable, 70 mass parts or less is more preferable, and 60 mass parts or less is further. preferable.

(Iv) Thermosetting resin As the thermosetting resin, phenol resin, epoxy resin, furan resin and the like are preferable. Among these, it is preferable to use the phenol resin from the viewpoints that the generation of combustible gas is small, the combustion suppressing effect is obtained, and the residual carbon rate after thermal decomposition (carbonization) is high.

Examples of the phenol resin include novolac phenol resin, phenol resin such as resol type resin, and modified phenol resin modified with urea, melamine, epoxy and the like. Among them, the phenol resin of the resol type is an acid, a viewpoint that does not require a curing agent such as an amine, a viewpoint of reducing odor during molding of a casting manufacturing structure, and a casting defect when the casting manufacturing structure is used as a mold. From the viewpoint of reducing

If novolac phenolic resin is used, a curing agent is required. Since the hardening agent is easily dissolved in water, it is preferably applied to the surface of the structure for casting manufacture after dehydration. Hexamethylenetetramine or the like is preferably used as the curing agent.

The thermosetting resin is maintained at 1000° C. in a nitrogen atmosphere in the TG pyrolysis measurement from the viewpoint that a shape is maintained and a carbon film is formed without decomposing even with heat during casting, and a good casting surface can be obtained. The weight loss rate is preferably 50% by mass or less, more preferably 45% by mass or less.

The content of the thermosetting resin in the structure for casting production is preferably 5 parts by mass or more with respect to 100 parts by mass of the structure for casting production, from the viewpoint of improving the strength of the structure for casting production and suppressing the amount of gas generation, 10 parts by mass or more is more preferable, 15 parts by mass or more is further preferable, 40 parts by mass or less is preferable, 30 parts by mass or less is more preferable, and 20 parts by mass or less is further preferable.

Since the organic fiber and the thermosetting resin are the main causes of the increase in the amount of gas generated during casting, the raw material species, the blending amount, and the mass ratio of the two are important.

By making the thermosetting resin content appropriate, it is possible to prevent the casting structure from sticking to the mold during dry molding in step (III), and separate the casting structure from the mold. This makes it possible to reduce the adhesion of the cured thermosetting resin to the surface of the mold, improve the dimensional accuracy of the casting manufacturing structure, and reduce the frequency of cleaning the surface of the mold.

(V) Surfactant having cationic nitrogen or polymer having cationic nitrogen It is considered that the surfactant having cationic nitrogen is adsorbed by the surface charge of the negatively charged organic fiber to form soft flocs. To be
The surfactant having cationic nitrogen is a surfactant containing cationic nitrogen in the hydrophilic group portion.
In the present invention, the cationic nitrogen possessed by the surfactant or the polymer is present in the compound as a nitrogen atom which becomes a positively charged nitrogen atom under the environment for carrying out the method for producing a structure for casting production of the present invention. It contains a nitrogen atom.

The cationic nitrogen-containing surfactant can be selected from cationic surfactants, amphoteric surfactants, and nonionic surfactants.

Examples of the cationic surfactant having cationic nitrogen include a quaternary ammonium salt and an alkylamine salt.
Examples of the quaternary ammonium salt include quaternary ammonium salts having one or two alkyl groups having 11 to 23 carbon atoms. Specific examples include quaternary ammonium salts represented by the following general formula (1).

[In formula, R< ¹ > shows a C11 or more and 23 or less alkyl group. R ² represents an alkyl group having 1 to 25 carbon atoms or a benzyl group. R ³ and R ⁴ each represent an alkyl group having 1 to 4 carbon atoms. X ⁻ represents an anion. ]

In general formula (1), R ¹ is preferably an alkyl group having 12 to 18 carbon atoms.
In general formula (1), the alkyl group of R ² preferably has 1 to 10 carbon atoms. R ² is more preferably an alkyl group having 1 to 18 carbon atoms or a benzyl group, and further preferably an alkyl group having 1 to 10 carbon atoms.
In general formula (1), R ³ and R ⁴ are each preferably an alkyl group having 1 or 2 carbon atoms.
In the general formula (1), X ⁻ is preferably a chloride ion (Cl ⁻ ).

Specific examples of the quaternary ammonium salt include lauryltrimethylammonium chloride, cetyltrimethylammonium chloride, stearyltrimethylammonium chloride, distearyldimethylammonium chloride, and alkyl (having 11 to 23 carbon atoms) benzyldimethylammonium chloride. ..

As a quaternary ammonium salt, quatamine 24P, cotamine 60W, cotamine 86P conc, cotamine 86W, cotamine D86P, sanizole C, sanizole B-50 (all are Kao Corporation) quaternary ammonium salt marketed. Can be used.

Examples of the alkylamine salt include an alkylamine salt having an alkyl group having 11 to 23 carbon atoms (for example, the salt is an acetate salt).
Specific examples of the alkylamine salt include coconut amine acetate and stearyl amine acetate.
As the alkylamine salt, an alkylamine salt commercially available under the trade names of acetamine 24 and acetamine 86 (both are Kao Corporation) can be used.

Examples of the amphoteric surfactant having a cationic nitrogen include betaine and amine oxide. Each of betaine and amine oxide preferably has an alkyl group having 11 to 23 carbon atoms.
Examples of betaine include lauryl betaine, stearyl betaine, 2-alkyl-N-carboxymethyl-N-hydroxyethyl imidazolinium betaine, and lauryl hydroxysulfobetaine.
As betaine, betaine commercially available under the trade names of Amchthor 20BS, Amchthor 24B, Amchthor 86B, Amchthol 20YB, and Amchthol 20HD (both are Kao Corporation) can be used.

Examples of the amine oxide include lauryl dimethyl amine oxide.
As the amine oxide, betaine commercially available under the trade name of Amphitol 20N (Kao Corporation) can be used.

Examples of the nonionic surfactant having a cationic nitrogen include polyoxyethylene alkylamine.
The alkyl group of polyoxyethylene alkylamine preferably has 11 or more and 23 or less carbon atoms.
The ethylene oxide average addition mole number of polyoxyethylene alkyl amine is preferably 1 or more and 40 or less.
Examples of the polyoxyethylene alkylamine include polyoxyethylene lauryl amine.
As the polyoxyethylene alkylamine, polyoxyethylene alkylamine commercially available under the trade name of Amate 105 (Kao Corporation) can be used.

Among these, the surfactant having cationic nitrogen is preferably a quaternary ammonium salt.

It is considered that the polymer having a cationic nitrogen is adsorbed by the surface charge of the negatively charged organic fiber to form a soft floc.
The polymer having cationic nitrogen is a polymer containing cationic nitrogen in the main chain or side chain.

The polymer having cationic nitrogen can be selected from a polymer having cationic nitrogen as a main chain monomer and a polymer having cationic nitrogen as a side chain functional group. A polymer having cationic nitrogen in the functional group serving as a side chain is preferable. For example, a polymer obtained by cation-modifying a homopolymer or copolymer of polyacrylamide or acrylic acid can be used.

Functional groups suitable for cation modification of polymers include quaternary ammonium groups and alkylamine groups. Examples of the quaternary ammonium group include quaternary ammonium groups having one or two alkyl groups having 11 to 23 carbon atoms. Specific examples thereof include groups derived from the quaternary ammonium compound represented by the general formula (1), and the preferred embodiments are also the same.

Further, a modified product of polyamidoamine with epichlorohydrin may be mentioned.

The polymer having a cationic nitrogen is a polymer having a primary amino group, a secondary amino group, a tertiary amino group, or a quaternary ammonium base, and examples thereof include cationized starch and cationic polyacrylamide (PAM). ), polyvinylamine, polydiallyldimethylammonium chloride (PDADMAC), polyamide epichlorohydrin (PAE), polyethyleneimine (PEI), and other water-soluble cationic polymers. The polymer having cationic nitrogen is preferably polyamide epichlorohydrin (PAE).

The content of the surfactant having a cationic nitrogen or the polymer having a cationic nitrogen in the structure for producing a casting is 100% by mass of the structure for producing a casting, from the viewpoint of adsorbing to the organic fiber and expanding the fibril of the organic fiber. 0.1 parts by mass or more, more preferably 0.2 parts by mass or more, further preferably 0.3 parts by mass or more, more preferably 1 part by mass or more, and preferably 5 parts by mass or less, It is more preferably 4 parts by mass or less, still more preferably 3 parts by mass or less.

Further, the content of the surfactant having a cationic nitrogen or the polymer having a cationic nitrogen in the structure for producing a casting is from the viewpoint of adsorbing to the surface charge of the negatively charged organic fiber to form a soft floc. Therefore, with respect to the content of the organic fiber, preferably 0.1 mass% or more, more preferably 1 mass% or more, further preferably 3 mass% or more, and preferably 25 mass% or less, more preferably 15 mass% % Or less, more preferably 13% by mass or less.

(Vi) Other components The structure for producing a casting of the present invention may further contain components such as an anionic compound and a coloring agent.

The casting production structure produced by the present invention preferably further contains an anionic compound.
The anionic compound forms a soft floc by the addition of the above-mentioned surfactant having a cationic nitrogen or a polymer having a cationic nitrogen, and then forms a bridge between organic fibers to form a hard floc resistant to mechanical external force. Used for the purpose of forming. In the present invention, the anionic compound refers to a compound which is ionized in an aqueous solution so that the main component of the compound becomes an anion.

Examples of the anionic compound include compounds selected from bentonite, colloidal silica, polyacrylamide, polyacrylic acid or salts thereof, and carboxymethyl cellulose or salts thereof. The salt is preferably sodium. The high molecular anionic compound may be a copolymer containing other monomer in addition to the monomer serving as the main skeleton.
The anionic compound may be used alone or in combination of two or more.
As the anionic compound, carboxymethyl cellulose or a salt thereof is preferable.

The weight average molecular weight of carboxymethyl cellulose is preferably 1,000 or more, more preferably 10,000 or more, and further preferably 20,000 or more. The weight average molecular weight is preferably 4,000,000 or less, more preferably 3,000,000 or less, and further preferably 2,000,000 or less. When the weight average molecular weight is 1000 or more, hard flocs can be formed, and when the weight average molecular weight is 10 million or less, mixing is easy at the time of mixing.

From the viewpoint of swelling prevention, the content of the anionic compound in the casting manufacturing structure is preferably 0.01 parts by mass or more, as solid content, relative to 100 parts by mass of the casting manufacturing structure. The amount is preferably 2 parts by mass or less, and more preferably 1 part by mass or less, from the viewpoint of preventing the structure for casting production from sticking to the mold.

[Structure of casting manufacturing structure, etc.]

In the method for producing a structure for casting production of the present invention, the average fiber length of the inorganic fibers in the obtained structure for casting production is preferably 1 mm or more and 5 mm or less.

The thickness of the casting manufacturing structure can be set according to the purpose of use and the like, but at least the thickness of the portion in contact with the molten metal is preferably 0.2 mm or more from the viewpoint of improving the strength of the casting manufacturing structure, 0.4 mm or more is more preferable, 0.5 mm or more is further preferable, 0.6 mm or more is still more preferable, 5 mm or less is preferable, 4 mm or less is more preferable, 3 from the viewpoint of improving the air permeability of the structure for casting production. It is more preferably 0.5 mm or less, still more preferably 3.0 mm or less.

From the viewpoint of maintaining the function of the casting manufacturing structure, the casting manufacturing structure preferably has a compressive strength of 80 N or more, and more preferably 100 N or more.

From the viewpoint of reducing the amount of gas generated during casting, the cast-manufacturing structure produced according to the present invention preferably has a water content of 10% by mass or less before use (before being subjected to casting). Mass% or less is more preferable, 5 mass% or less is further preferable, and 3 mass% or less is still more preferable.

The density of for casting structure produced by the present invention, from the viewpoint of handling properties and processability workability for casting structure is preferably 3 g / cm ³ or less, more preferably 2 g / cm ³ or less, 1 It is more preferably 0.5 g/cm ³ or less. Further, from the viewpoint of maintaining the strength of the structure for producing a casting, 0.5 g/cm ³ or more is preferable, 0.6 g/cm ³ or more is more preferable, and 0.7 g/cm ³ or more is further preferable.

<Method for manufacturing structure for casting production>
The method for producing a structure for producing a casting according to the present invention is a slurry composition containing organic fiber, inorganic fiber, inorganic particles, thermosetting resin, a surfactant having cationic nitrogen or a polymer having cationic nitrogen, and water. There is a step (I) of obtaining a product, a step (II) of forming the slurry composition into a paper to obtain a fiber laminate, and a step (III) of dehydrating and drying the fiber laminate.

<Process (I)>
In the step (I), a slurry composition containing organic fibers, inorganic fibers, inorganic particles, thermosetting resin, a surfactant having cationic nitrogen or a polymer having cationic nitrogen, and water is obtained.
Step (I) includes (a) organic fiber, (b) inorganic fiber, (c) inorganic particles, (d) thermosetting resin, (e) cationic surfactant, amphoteric surfactant and nonionic interface. It may be a step of obtaining a slurry composition containing (f) water and a surfactant having one or more kinds of cationic nitrogen selected from activators.
In the step (I), (a) organic fiber, (b) inorganic fiber, (c) inorganic particle, (d) thermosetting resin, (e') quaternary ammonium salt, alkylamine salt, betaine, amine oxide. And a surfactant having at least one cationic nitrogen selected from polyoxyethylene alkylamine, and (f) a step of obtaining a slurry composition containing water.

In the step (I), after mixing water and a surfactant having a cationic nitrogen or a polymer having a cationic nitrogen, inorganic fibers are mixed to obtain the slurry composition. It is preferable from the viewpoint of obtaining. In step (I), mixing water with a surfactant having cationic nitrogen or a polymer having cationic nitrogen before the inorganic fibers are first mixed with water results in a uniform slurry composition. It is preferable from the viewpoint.

The step (I) is a step (I-1) of obtaining a mixture (A) containing organic fibers and water, a surfactant having a cationic nitrogen or a polymer having a cationic nitrogen in the mixture (A), and Having a step (I-2) of adding an inorganic fiber,
In the step (I-2), a surfactant having a cationic nitrogen or a polymer having a cationic nitrogen is added to the mixture (A) before adding the inorganic fiber to the mixture (A),
It is preferable to mix the thermosetting resin and the inorganic particles in at least one of the step (I-1) and the step (I-2).

Step (I) is
A step (I-1) of obtaining a mixture (A) containing organic fibers and water,
A step (I-2-1) of obtaining a mixture (B) by mixing the mixture (A) with a thermosetting resin and inorganic particles; and
A step (I-2-2) of mixing the mixture (B) with a surfactant having cationic nitrogen or a polymer having cationic nitrogen, and then mixing inorganic fibers.
It is preferable to have

Further, in the step (I), from the viewpoint of adsorbing to the surface charges of the negatively charged organic fibers to form soft flocs, a surfactant having cationic nitrogen or a polymer having cationic nitrogen is added to the organic fibers. On the other hand, preferably 0.1% by mass or more, more preferably 1% by mass or more, further preferably 3% by mass or more, and preferably 25% by mass or less, more preferably 15% by mass or less, further preferably 13% by mass or less. Mix up to mass%.

[Step (I-1)]
In the step (I-1), a mixture (A) containing organic fibers and water is obtained. The mixture (A) is prepared by dispersing organic fibers in water. It is preferable to beat the mixture (A) containing organic fibers and water. In the step (I-1), a mixture (A) containing organic fibers and water as a dispersion medium is prepared.

The content of the organic fiber in the slurry composition (hereinafter, also referred to as a raw material slurry) obtained in the step (I) is 100% from the viewpoint of improving the moldability of the casting manufacturing structure. 1 part by mass or more, preferably 5 parts by mass or more, more preferably 10 parts by mass or more, still more preferably 20 parts by mass or more with respect to parts by mass, from the viewpoint of suppressing the gas generation amount during casting, the process ( I) It is preferably 40 parts by mass or less, and more preferably 30 parts by mass or less with respect to 100 parts by mass of the slurry raw material used as a whole. An amount of organic fiber corresponding to this amount is used for preparing the mixture (A) in step (I-1).
The slurry raw material is organic fiber, inorganic fiber, inorganic particles, thermosetting resin and surfactant having cationic nitrogen or polymer having cationic nitrogen, or organic fiber, inorganic fiber, inorganic particles, thermosetting The resin, the surfactant having cationic nitrogen or the polymer having cationic nitrogen, and the anionic compound are used, and the total mass of these slurry raw materials is 100 parts by mass (the same applies hereinafter).

In the step (I-1), the amount of water for obtaining the mixture containing the organic fiber and water is 600 parts by mass with respect to 100 parts by mass of the slurry raw material used in the entire step (I) from the viewpoint of improving the beating efficiency. The amount is preferably at least 700 parts by mass, more preferably at least 700 parts by mass, even more preferably at least 770 parts by mass, preferably at most 1000 parts by mass, more preferably at most 900 parts by mass, still more preferably at most 870 parts by mass.

The content of the organic fibers in the mixture (A) containing water in the step (I-1) is preferably 0.1% by mass or more, and 0.48% by mass, from the viewpoint of improving the moldability of the structure for casting production. The above is more preferable, 1.0 mass% or more is still more preferable, 1.9 mass% or more is still more preferable, and 6.2 mass% or less is preferable and 4.7 mass% from the viewpoint of suppressing the gas generation amount during casting. % Or less is more preferable. When the mixture (A) is beaten, the content is the content based on the mixture (A) before beating.

The content of water in the mixture (A) containing water in the step (I-1) is preferably 87.6% by mass or more, and more preferably 92.2% by mass or more, from the viewpoint of suppressing the gas generation amount during casting. From the viewpoint of improving the moldability of the structure for producing a casting, 99.4 mass% or less is preferable, 98.0 mass% or less is more preferable, and 97.5 mass% or less is further preferable.

In addition, in a process (I-1), a dispersion medium other than water can also be used. Examples of the dispersion medium other than water include solvents such as ethanol, methanol, dichloromethane, acetone and xylene. These may be used alone or in combination of two or more.

When the resulting mixture (A) is beaten, the mixture (A) (mixture of slurry raw materials) is defibrated in a pulper at a predetermined frequency for a predetermined time, then transferred to a refiner and beaten at a predetermined strength for a predetermined time. Perform processing.

Specifically, a mixture containing organic fibers and water is put into a pulper, and from the viewpoint of improving the disaggregation efficiency, 2000 kg of the mixture is preferably disaggregated at a frequency of 10 Hz or more, and more preferably 20 Hz or more. , 30 Hz or higher is more preferable, and from the viewpoint of reducing power consumption, 200 Hz or lower is preferable, 150 Hz or lower is more preferable, and 100 Hz or lower is further preferable. The disaggregation time is preferably 1 minute or more, more preferably 2 minutes or more, further preferably 3 minutes or more from the viewpoint of improving disaggregation efficiency, and preferably 30 minutes or less and 25 minutes or less from the viewpoint of reducing power consumption. It is more preferably 20 minutes or less.

Further, the beating of the mixture containing the organic fiber and water, preferably the mixture containing the organic fiber and water after disintegration is preferably performed using a beating means selected from a refiner, a beater and a PFI mill. From the viewpoint, it is more preferable to use a refiner. The load value in the case of using the refiner is preferably 5 kW or more, more preferably 7 kW or more, further preferably 10 kW or more, from the viewpoint of improving the beating efficiency, and preferably 50 kW or less, or 30 kW or less from the viewpoint of reducing power consumption. More preferably, 20 kW or less is further preferable. The flow rate when using a refiner is preferably 10 L/min or more, more preferably 20 L/min or more, further preferably 30 L/min or more, from the viewpoint of improving production efficiency, and 700 L/min or less from the viewpoint of improving beating efficiency. Is preferred, 600 L/min or less is more preferred, and 500 L/min or less is even more preferred. The treatment time when using a refiner is preferably 5 minutes or more, more preferably 8 minutes or more, still more preferably 10 minutes or more, from the viewpoint of improving beating efficiency, and preferably 90 minutes or less from the viewpoint of improving production efficiency. It is more preferably 80 minutes or less, still more preferably 70 minutes or less.

[Step (I-2)]
In the step (I-2), a surfactant having a cationic nitrogen or a polymer having a cationic nitrogen and an inorganic fiber are added to the mixture (A). Then, in the step (I-2), a surfactant having a cationic nitrogen or a polymer having a cationic nitrogen is added to the mixture (A) before adding the inorganic fiber to the mixture (A).

The inorganic particles and the thermosetting resin are preferably used in the step (I-2).
It is also preferable to use an anionic compound in step (I-2).

The anionic compound is preferably added to the mixture (A) after the surfactant having cationic nitrogen or the polymer having cationic nitrogen. That is, a surfactant having a cationic nitrogen or a polymer having a cationic nitrogen is added to the mixture (A) before adding the inorganic fiber to the mixture (A), and the inorganic fiber is added to the mixture (A). It is preferable that the anionic compound is added after the addition.

When the inorganic particles, the thermosetting resin and the anionic compound are used in the step (I-2), the inorganic fiber, the inorganic particles, the thermosetting resin, the cationic nitrogen-containing surfactant or the cationic agent for the mixture (A) are used. Examples of the order of adding the nitrogen-containing polymer and the anionic compound include the following modes.
Aspect (i) A thermosetting resin, inorganic particles, a surfactant having cationic nitrogen or a polymer having cationic nitrogen, an anionic compound, and an inorganic fiber are added in this order to the mixture (A).
Aspect (ii) A thermosetting resin, inorganic particles, a surfactant having cationic nitrogen or a polymer having cationic nitrogen, an inorganic fiber, and an anionic compound are added to the mixture (A) in this order.
Aspect (iii) To the mixture (A), a surfactant having cationic nitrogen or a polymer having cationic nitrogen, an inorganic fiber, an anionic compound, a thermosetting resin, and inorganic particles are added in this order.
Aspect (iv) A thermosetting resin, a surfactant having a cationic nitrogen or a polymer having a cationic nitrogen, an inorganic fiber, an inorganic particle, and an anionic compound are sequentially added to the mixture (A).
Aspect (v) To the mixture (A), a surfactant having cationic nitrogen or a polymer having cationic nitrogen, an inorganic fiber, an anionic compound, a thermosetting resin, and inorganic particles are added in this order.
Of course, modes other than these may be used. Also, a plurality of components may be added at the same time.

In the present invention, as described above, it is preferable to add the inorganic particles and the thermosetting resin to the mixture (A) in the step (I-2). In addition, in the present invention, in the step (I-2), inorganic particles and a thermosetting resin are added to the mixture (A), and after the inorganic particles and the thermosetting resin are added to the mixture (A), cationic nitrogen is added. It is preferable to add a surfactant having a cation or a polymer having a cationic nitrogen. The method of the above aspect (i) is preferable.

By the step (I-2), an organic fiber, an inorganic fiber, an inorganic particle, a thermosetting resin, a surfactant having a cationic nitrogen or a polymer having a cationic nitrogen, water, and optionally an anionic compound are contained. The slurry composition (raw material slurry) of step (I) is obtained.

The content of the inorganic fibers in the raw material slurry is 100% by mass of the slurry raw material used in the entire step (I), from the viewpoint of improving the strength of the casting manufacturing structure, suppressing heat shrinkage, and improving seizure resistance. 1 part by mass or more is preferable, 2 parts by mass or more is more preferable, 3 parts by mass or more is further preferable, generation of lumps at the time of preparing the slurry in the step (I) is suppressed, and the surface smoothness of the casting manufacturing structure is improved. From the viewpoint of improvement, it is preferably 10 parts by mass or less, more preferably 9 parts by mass or less, and further preferably 8 parts by mass or less. An amount of the inorganic fiber corresponding to this amount is used in the step (I-2). Preferably, the total amount of inorganic fibers used in the entire step (I), that is, the total amount of inorganic fibers blended in the raw material slurry is used in the step (I-2).

The content of the inorganic particles in the raw material slurry is preferably 10 parts by mass or more based on 100 parts by mass of the slurry raw material used in the entire step (I), from the viewpoint of improving the hot strength during casting of the structure for producing a casting. , 20 parts by mass or more, more preferably 40 parts by mass or more, further preferably 80 parts by mass or less, more preferably 70 parts by mass or less, and 60 parts by mass or less from the viewpoint of improving the strength of the casting manufacturing structure. More preferable. Preferably, an amount of inorganic particles corresponding to this amount is used in step (I-2).

The content of the thermosetting resin in the raw material slurry is 5 parts by mass with respect to 100 parts by mass of the slurry raw material used in the entire step (I) from the viewpoint of improving the strength of the structure for producing a casting and suppressing the amount of gas generated during casting. The amount is preferably at least 10 parts by mass, more preferably at least 10 parts by mass, still more preferably at least 15 parts by mass, preferably at most 40 parts by mass, more preferably at most 30 parts by mass, still more preferably at most 20 parts by mass. Preferably, an amount of thermosetting resin corresponding to this amount is used in step (I-2).

The content of the cationic nitrogen-containing surfactant or the cationic nitrogen-containing polymer in the raw material slurry is solid content from the viewpoint of forming soft flocs with respect to 100 parts by mass of the slurry raw material used in the entire step (I). Is preferably 0.1 parts by mass or more, more preferably 0.2 parts by mass or more, further preferably 0.3 parts by mass or more, and 5 parts by mass from the viewpoint of suppressing the gas generation amount of the casting manufacturing structure. The following is preferable, 4 parts by mass or less is more preferable, and 3 parts by mass or less is further preferable.

The content of the anionic compound in the raw material slurry is 0.005 parts by mass or more in terms of solid content with respect to 100 parts by mass of the slurry raw material used in the entire step (I), from the viewpoint of preventing swelling of the casting manufacturing structure. Is more preferable, and 0.01 part by mass or more is more preferable. From the viewpoint of preventing sticking to the mold of the casting manufacturing structure, 2 parts by mass or less is preferable, and 1 part by mass or less is more preferable.

The average fiber length of the inorganic fibers in the raw material slurry is preferably 1 mm or more, more preferably 2 mm or more, from the viewpoint of improving the strength of the casting manufacturing structure and suppressing heat shrinkage, and the moldability of the casting manufacturing structure. From the viewpoint of improvement, it is preferably 5 mm or less, more preferably 4 mm or less. Inorganic fibers having this average fiber length are preferably used for preparing the raw material slurry.

The major axis/minor axis ratio of the inorganic fibers in the raw material slurry, preferably carbon fibers, is from the viewpoint of improving the strength of the casting manufacturing structure, the viewpoint of improving the moldability of the casting manufacturing structure and the casting manufacturing structure. From the viewpoint of suppressing heat shrinkage, it is preferably 1 or more, more preferably 10 or more, still more preferably 50 or more, and preferably 5000 or less, more preferably 2000 or less, still more preferably 1000 or less.

From the viewpoint of improving the surface smoothness of the structure for producing a casting, in the step (I), the content of the inorganic fiber is 0.40% by mass or less based on the amount of water in the mixture in which the inorganic fiber is first mixed. It is preferably used in a proportion, more preferably 0.25% by mass or less, further preferably 0.18% by mass or less, and preferably 0.01% by mass or more, more preferably 0.03% by mass or more, and 0. 06 mass% or more is more preferable. In the present invention, in the step (I-2), it is preferable to use the inorganic fibers in a proportion of 0.40% by mass or less with respect to the amount of water used in the step (I-1), and 0.25% by mass. % Or less is more preferable, 0.18% by mass or less is further preferable, 0.01% by mass or more is preferable, 0.03% by mass or more is more preferable, and 0.06% by mass or more is further preferable.

The content of the total solid content in the slurry composition obtained in the step (I) is preferably 1% by mass or more, more preferably 2% by mass or more, from the viewpoint of improving the moldability of the structure for producing a casting. 0.3% by mass or more is more preferable, 5% by mass or less is preferable, 4% by mass or less is more preferable, and 3.5% by mass or less is further preferable.

The content of the organic fibers in the slurry composition obtained in the step (I) is preferably 0.03 mass% or more, and more preferably 0.14 mass% or more from the viewpoint of improving the moldability of the structure for casting production. The content is preferably 0.28% by mass or more, more preferably 0.55% by mass or more, further preferably 3% by mass or less, and more preferably 1.3% by mass or less, from the viewpoint of suppressing the amount of gas generated during casting. 1 mass% or less is more preferable.

The content of the inorganic fibers in the slurry composition obtained in the step (I) is 0.03% by mass or more from the viewpoint of improving the strength of the casting manufacturing structure, suppressing heat shrinkage, and improving seizure resistance. Is preferable, 0.06 mass% or more is more preferable, 0.08 mass% or more is further preferable, generation of lumps at the time of slurry preparation in step (I) is suppressed, and surface smoothness of the structure for casting production is improved. From the viewpoint of controlling the content, 0.26 mass% or less is preferable, 0.25 mass% or less is more preferable, and 0.24 mass% or less is further preferable.

The content of the inorganic particles in the slurry composition obtained in the step (I) is preferably 0.3% by mass or more, and 0.6% by mass or more from the viewpoint of improving the hot strength of the structure for producing a casting. Is more preferable, 1.1% by mass or more is more preferable, 2.6% by mass or less is preferable from the viewpoint of suppressing the generation of lumps during the preparation of the slurry in the step (I) and improving the strength of the structure for casting production. It is preferably 2.3% by mass or less, more preferably 2.0% by mass or less.

The content of the thermosetting resin in the slurry composition obtained in the step (I) is preferably 0.14% by mass or more, and 0.28% by mass or more from the viewpoint of improving the strength of the structure for producing a casting. More preferably, 0.41 mass% or more is further preferable, from the viewpoint of suppressing the gas generation amount during casting, 1.3 mass% or less is preferable, 1.0 mass% or less is more preferable, and 0.7 mass% or less is More preferable.

The content of the surfactant having cationic nitrogen or the polymer having cationic nitrogen in the slurry composition obtained in the step (I) is 0.005% by mass as a solid content from the viewpoint of forming soft flocs. Or more is preferable, 0.007 mass% or more is more preferable, 0.01 mass% or more is still more preferable, and 0.4 mass% or less is preferable, and 0.3 mass% or less is preferable from the viewpoint of suppressing the gas generation amount of the casting manufacturing structure. It is more preferably at most% by mass, and even more preferably at most 0.2% by mass.

The content of the anionic compound in the slurry composition obtained in the step (I) is preferably 0.0003 mass% or more, and more preferably 0.0004 mass% or more, as solid content, from the viewpoint of forming hard flocs. Preferably, from the viewpoint of preventing the casting structure from sticking to the mold, 0.03 mass% or less is preferable, and 0.02 mass% or less is more preferable.

In the present invention, water can be added to the mixture in the process of forming the slurry composition in any of the steps (I). For example, a step of adding water to the mixture (A) obtained in step (I-1) can be provided between step (I-1) and step (I-2). The amount of water added may be such that the content of each component in the finally obtained slurry composition falls within the above range.

A preferable aspect of the mass ratio of the organic fibers and the inorganic fibers in the slurry composition obtained in the step (I) is the same as the mass ratio of the organic fibers and the inorganic fibers in the casting manufacturing structure.

If necessary, additives such as a coloring agent and a preservative can be added to the raw material slurry.

<Process (II)>
In the step (II), the slurry composition obtained in the step (I) is formed into a paper to obtain a fiber laminate. That is, the raw material slurry is used to reduce the water content of the raw material slurry and mold the components in the slurry to fabricate a fiber laminate of the casting manufacturing structure.

In the papermaking of the slurry composition (raw material slurry) obtained in the step (I), for example, two sets of split dies are butted to form a shape substantially corresponding to the outer shape of the casting manufacturing structure. It is possible to use a mold in which a cavity that is open to the outside is formed inside. Each split mold is provided with a large number of communication holes for communicating the outside with the cavity, and the inner surface of each split mold is covered with a net having a mesh of a predetermined size. Then, a predetermined amount of the raw material slurry is injected into the cavity of the mold by using a pressure pump or the like, while the liquid content is sucked and discharged through the communication hole to deposit the solid content of the raw material slurry on the net. The pressure of the raw material slurry under pressure is preferably 0.01 MPa or more, more preferably 0.05 MPa or more, still more preferably 0.1 MPa or more, from the viewpoint of improving the production efficiency, and inject the raw material slurry into the mold uniformly. From the viewpoint, 5 MPa or less, more preferably 2 MPa or less, and further preferably 0.5 MPa or less.

When a fiber laminate having a predetermined thickness is formed on the net by injecting a predetermined amount of the raw material slurry, the pressure injection of the raw material slurry is stopped.

<Process (III)>
In the step (III), the fiber laminate obtained in the step (II) is dehydrated and then dried. The fiber laminate obtained in the step (II) is dehydrated to a predetermined water content by pressurizing air into the cavity.

Next, the fiber laminate is dry-molded. In this dry molding process, use a dry mold which has a shape corresponding to the outer shape of the casting manufacturing structure to be molded by abutting a pair of split molds and in which a cavity opening to the outside is formed. You can Then, the drying mold is heated to a predetermined temperature, and the dehydrated fiber laminate is loaded into the drying mold.

Next, an elastic, expandable and contractible hollow core (elastic core) is inserted into the cavity, and a pressurized fluid is supplied into the core to move the core into the cavity. Inflate. Then, the fiber laminate is pressed against the surface on which the cavity is formed, and is dried while transferring the shape of the inner surface of the cavity. For the core, for example, urethane, fluorine-based rubber, silicone-based rubber or elastomer can be used.

Examples of the pressurized fluid for expanding the core include compressed air, preferably heated compressed air, oil, preferably heated oil, and various other liquids. The pressure for supplying the pressurized fluid is preferably 0.01 MPa or more, more preferably 0.05 MPa or more, further preferably 0.1 MPa or more from the viewpoint of improving the smoothness of the inner surface of the molded product, and from the viewpoint of improving the life of the core. It is preferably 5 MPa or less, more preferably 2 MPa or less, still more preferably 0.5 MPa or less.

The heating temperature (mold temperature) of the drying mold is preferably 180° C. or higher, more preferably 200° C. or higher from the viewpoint of reducing the drying time, and 250° C. or lower, further 240° C. from the viewpoint of preventing deterioration of surface property due to charring. The following are preferred.

After the fiber laminate is dried, the pressurized fluid in the core is removed, the core is contracted, and the fiber laminate is taken out. Then, the dry mold is opened, and the dry-molded structure for casting production is taken out.

The structure for casting production thus obtained includes organic fibers, inorganic fibers, inorganic particles, thermosetting resins, cationic nitrogen-containing surfactants or cationic nitrogen-containing polymers, and any anionic compound. Since the components are evenly dispersed, the occurrence of cracks and the like due to heat shrinkage is suppressed, high hot strength is obtained, and surface smoothness is excellent. Further, since the fiber laminate is molded by being pressed against the surface of the mold for forming the dry mold from the inside thereof, the inner surface and the outer surface have high smoothness. Therefore, when it is used for manufacturing a casting, the obtained casting has excellent surface smoothness. In addition, since a bonding step is not necessary even in the case of forming a hollow shape or a complicated three-dimensional shape, a seam and a thick portion due to bonding do not exist in the finally obtained mold or the like. Also in this respect, it is possible to manufacture a casting having a uniform wall thickness, high molding accuracy and mechanical strength, high dimensional accuracy, and excellent surface smoothness. Therefore, it can be applied not only to the main mold and the core, but also to the manufacture of a structure such as a runner having a fitting portion and a screw portion. In addition, when there is a concern that gas defects will occur due to the material and shape of the casting, the mold or the like may be preliminarily heat-treated at 200°C or higher and 250°C or lower in a reducing atmosphere.

<Method for producing slurry composition for casting manufacturing structure>
The method for producing a slurry composition for casting casting structure of the present invention comprises an organic fiber, an inorganic fiber, an inorganic particle, a thermosetting resin, a surfactant having cationic nitrogen or a polymer having cationic nitrogen, and water. A method for producing a slurry composition for casting casting structure, which comprises the step (I) of obtaining a slurry composition containing the composition.

This method corresponds to step (I) of the method for manufacturing a structure for manufacturing a casting according to the present invention. Therefore, the specific method and the preferred embodiment are also the same as the step (I), and further, the step (I-1) and the step (I-2) of the method for producing a structure for producing a casting according to the present invention. The matters described in step (I) of the method for producing a structure for casting production of the present invention, and further in steps (I-1) and (I-2) are the method for producing a slurry composition for a structure for casting casting. Applicable to

Also in the method for producing a slurry composition for casting casting structure of the present invention, in the step (I), after mixing water and a surfactant having cationic nitrogen or a polymer having cationic nitrogen, the inorganic fiber is mixed with the inorganic fiber. Mixing to obtain the slurry composition is preferable from the viewpoint of obtaining a uniform slurry composition.

Also in the method for producing the slurry composition for casting casting structure of the present invention, the step (I) includes a step (I-1) of obtaining a mixture (A) containing organic fibers and water, and the mixture (A). ) Has a step (I-2) of adding a surfactant having a cationic nitrogen or a polymer having a cationic nitrogen and an inorganic fiber,
In the step (I-2), a surfactant having a cationic nitrogen or a polymer having a cationic nitrogen is added to the mixture (A) before adding the inorganic fiber to the mixture (A),
Mixing the thermosetting resin and the inorganic particles in at least one of the step (I-1) and the step (I-2),
It is preferable.

Also in the method for producing a slurry composition for casting casting structure of the present invention, the step (I) includes
A step (I-1) of obtaining a mixture (A) containing organic fibers and water,
A step (I-2-1) of obtaining a mixture (B) by mixing the mixture (A) with a thermosetting resin and inorganic particles; and
A step (I-2-2) of mixing the mixture (B) with a surfactant having cationic nitrogen or a polymer having cationic nitrogen, and then mixing inorganic fibers.
It is preferable to have

Also in the method for producing the slurry composition for casting casting structure of the present invention, in the step (I), cationic nitrogen is adsorbed on the surface charges of the negatively charged organic fibers to form soft flocs. The polymer having a surfactant or cationic nitrogen is preferably 0.1% by mass or more, more preferably 1% by mass or more, further preferably 3% by mass or more, and preferably 25% with respect to the organic fiber. The mixture is used in an amount of not more than 15% by mass, more preferably not more than 15% by mass, further preferably not more than 13% by mass.

Also in the method for producing a slurry composition for casting casting structure of the present invention, it is preferable to obtain a slurry composition further containing an anionic compound in the step (I).

<Casting manufacturing method>
Next, a method for manufacturing a casting according to the present invention will be described based on its preferred embodiment.

In the manufacturing method of the present embodiment, the casting-manufacturing structure obtained as described above is embedded in a predetermined position in the casting sand and molded. The casting manufacturing structure manufactured according to the present invention can be used as a mold or a structure used in manufacturing a casting. As the foundry sand, the usual ones conventionally used for the production of this kind of foundry can be used without particular limitation. The foundry sand may not be hardened with a binder, but may be hardened if necessary. When the structure for producing a casting is a hollow core, it is not necessary to fill the core with the molding sand, but it can be filled.

Then, the molten metal is poured from the pouring port to perform casting. At this time, the thermosetting resin and the organic fiber are thermally decomposed and carbonized, but the inorganic fiber suppresses thermal contraction due to the thermal decomposition. For this reason, the molds are hardly cracked, the molds themselves are not damaged, and the molten metal is hardly inserted into the molds or the foundry sand is not attached. Further, since the surface smoothness of the mold or the like is maintained by the carbonized film formed by the thermal decomposition, the surface smoothness of the obtained casting becomes good.

After the casting is finished, the casting is cooled to a predetermined temperature, the casting frame is disassembled to remove the foundry sand, and the casting manufacturing structure is removed by blasting to expose the casting. At this time, since the organic fibers are thermally decomposed, it is easy to remove the mold or the like. Then, if necessary, the casting is subjected to post-treatment such as trimming to complete the production of the casting.

The method for producing a casting according to the present embodiment includes the organic fiber, the inorganic fiber, the inorganic particles, the thermosetting resin, the surfactant having the cationic nitrogen or the polymer having the cationic nitrogen, and optionally the anionic. Since a mold or the like containing a compound is used, hot strength can be maintained by the inorganic fiber and the thermosetting resin, and a casting having excellent dimensional accuracy and surface smoothness can be manufactured. Further, since it is possible to easily remove the cast-manufacturing structure by forming voids inside the cast-manufacturing structure by thermal decomposition of the organic fibers or the like, it is possible to easily dispose of the waste product as compared with the conventional method. In addition to being able to carry out, it is possible to significantly reduce the amount of waste generated, and it is also possible to greatly reduce the time and labor of the treatment. Further, since it is not always necessary to cure the molding sand with the binder, the molding sand can be easily regenerated.

The present invention is not limited to the above-described embodiments, and can be modified as appropriate without departing from the spirit of the present invention.

The casting manufacturing structure of the present invention, as in the above-described embodiment, in forming a three-dimensional hollow-shaped casting manufacturing structure, etc., is formed into a molded body by a wet papermaking method, dehydrated, and dried and molded. Although it is preferable to manufacture a structure for manufacturing a casting through the above, it is also possible to manufacture a structure for manufacturing a casting by forming a sheet-shaped molded body from the raw material slurry by papermaking and winding this as a paper tube.

Further, it is preferable to manufacture so as to obtain a casting manufacturing structure corresponding to the final shape after dry molding, but the molded body obtained after drying is cut and divided, and the divided parts are fitted together. It can also be manufactured in a form that can be connected by screwing or screwing. In this case, it is preferable that the end portion or the divided portion is molded in advance in a form having a fitting or screwing portion.

The casting manufacturing method of the present invention can be applied to casting of cast iron, aluminum and alloys thereof, copper and alloys thereof, and non-ferrous metals such as nickel and lead.

The following examples describe the practice of the invention. The examples are illustrative of the invention and are not intended to limit the invention.

[Test Example 1]
A surfactant having the type and amount of cationic nitrogen shown in Table 1 was dissolved in water, and then the amount of inorganic fibers shown in Table 1 was added to obtain a slurry. The inorganic fibers used were as follows.
Inorganic fiber: carbon fiber [trade name "TCTR03245" manufactured by Mitsubishi Rayon Co., Ltd., average fiber length 3 mm, average fiber diameter 7 μm (long axis/short axis ratio=429); sizing agent: water-soluble polyamide, adhesion amount 1 .5%]

<Dama Evaluation>
The slurry prepared above was stirred for 60 minutes in a stirring tank having an inner diameter of 95 mm and a height of 120 mm under the stirring conditions of rotation speed: 190 rpm and stirring blade: 70 mm (propeller type).
The slurry after stirring was filtered through a mesh (opening about 3 mm) to separate lumps, and the number of lumps and the dry mass of the lumps were measured. From the dry mass of the lump and the amount of the inorganic fiber used, the lump occurrence rate was calculated by the following formula. The results are shown in Table 1.
Dama occurrence rate (%) = (dry mass of lump / amount of inorganic fiber used) x 100

All the surfactants in the table are manufactured by Kao Corporation. More information on some of the surfactants is given below.
Amate 105: polyoxyethylene lauryl amine, HLB 9.8
-Sanisol C: alkylbenzyldimethylammonium chloride, the alkyl group has 8 to 18 carbon atoms
-Sanisol B-50: Alkylbenzyldimethylammonium chloride, the alkyl group has 8 to 18 carbon atoms.

[Example 1]
The following slurry raw materials were used in the amounts shown in Table 2 to obtain a slurry composition.
Among the addition amounts in Table 2, those indicated by "addition amount (g)" are the addition amounts of each component in the form.
In addition, among the addition amounts in Table 2, those represented by "addition amount (parts by mass)" are all parts by mass of each component in terms of effective components with respect to 100 parts by mass of the slurry raw material. In Table 2, the slurry raw material is a cationic compound, an organic fiber, an inorganic fiber, a thermosetting resin, an inorganic particle, and an anionic compound.

Organic fiber (waste paper water dispersion having a concentration of 3.8% by mass), the amount shown in Table 2 and water for dilution were put into a stirring tank and stirred for 2 minutes to obtain a mixture (A) [step (I-1)].
A thermosetting resin and inorganic particles were simultaneously added to this mixture (A), and the mixture was stirred for 2 minutes to obtain a mixture (B) [step (I-2-1)].
Further, the amount of the cationic nitrogen-containing surfactant, the anionic compound, and the inorganic fiber shown in Table 1 were added to the mixture (B) in this order, and the mixture was stirred and mixed to prepare an aqueous slurry composition. [Step (I-2-2)].
In each step, stirring was performed for 2 minutes after addition of each component. The total mass of all solids in the slurry composition was about 3.0 mass %.

The obtained raw material slurry is subjected to the step (II) of forming the raw material slurry into a paper to obtain a fiber laminate, and then the step (III) of dehydrating and drying the fiber laminate is carried out to obtain a structure for casting production. It can be manufactured.

[Organic fiber]
-Organic fiber: Aqueous dispersion of used newspaper obtained by the following method (organic fiber concentration 3.8% by mass)
Waste newspaper was treated with a water dispersion medium for 10 minutes with a juicer mixer so that the concentration was 3.8% by mass. This operation is also part of the step (I-1).

[Inorganic fiber]
Inorganic fiber: carbon fiber [trade name "TCTR03245" manufactured by Mitsubishi Rayon Co., Ltd., average fiber length 3 mm, average fiber diameter 7 μm (long axis/short axis ratio=429); sizing agent: water-soluble polyamide, adhesion amount 1 .5%]

[Inorganic particles]
・Obsidian: Kinsei Matec Co., Ltd., “Nice Catch Flower #330”, average particle size 30 μm

[Thermosetting resin]
-Phenolic resin: Air Water Co., Ltd., trade name "Bellpearl S-890" (resol type)

[Surfactant Having Cationic Nitrogen]
・Surfactants shown in Table 2

[Polymer having cationic nitrogen]
PAE: Polyamide epichlorohydrin [Seiko PMC Co., Ltd., trade name WS-4020, solid content 25 mass%]

[Anionic compound]
Sodium carboxymethylcellulose: 1% by mass aqueous solution of sodium carboxymethylcellulose (indicated as 1% by mass CMC solution in the table)

[Dispersion medium]
・Dispersion medium: water

<Dama Evaluation>
The slurry composition prepared above was stirred in an agitation tank having an inner diameter of 140 mm and a height of 230 mm under the following stirring conditions: rotation speed: 500 rpm, stirring blades: upper stage 70 mm (fan turbine type), lower stage 50 mm (V-type right angle paddle type). Stir for 20 hours.
The slurry composition after stirring was filtered through a mesh (opening about 3 mm) to separate the lumps, and the number of lumps and the dry mass of the lumps were measured. From the dry mass of the lump and the amount of the inorganic fiber used, the lump occurrence rate was calculated by the following formula. The results are shown in Table 2.
Dama occurrence rate (%) = (dry mass of lump / amount of inorganic fiber used) x 100

The amount of water added in the table is the amount added as water that does not include the amount taken in from other slurry raw materials.
In addition, the addition amounts of the surfactant having cationic nitrogen and the polymer (PAE) having cationic nitrogen in the table are the addition amounts in the form of the product.
The surfactants in the table are all manufactured by Kao Corporation. More information on some of the surfactants is given below.
-Coatamine 60W: Cetyl trimethyl ammonium chloride, 30 mass% active ingredient
-Amphitol 24B: lauryl betaine (lauryl dimethylaminoacetic acid betaine), 26 mass% active ingredient

Claims (12)

Step (I) of obtaining a slurry composition containing organic fiber, inorganic fiber, inorganic particles, thermosetting resin, surfactant having cationic nitrogen or polymer having cationic nitrogen, and water, the slurry composition A method for producing a structure for producing a casting, which comprises a step (II) of forming a paper to obtain a fiber laminate, and a step (III) of dehydrating and drying the fiber laminate ,
In the step (I), water, organic fibers, and a surfactant having cationic nitrogen or a polymer having cationic nitrogen are mixed, and then inorganic fibers are mixed to obtain the slurry composition,
A method for manufacturing a structure for manufacturing a casting . The step (I) is a step (I-1) of obtaining a mixture (A) containing organic fibers and water, and a surfactant having a cationic nitrogen or a polymer having a cationic nitrogen in the mixture (A). And a step (I-2) of adding an inorganic fiber,
In the step (I-2), a surfactant having a cationic nitrogen or a polymer having a cationic nitrogen is added to the mixture (A) before adding the inorganic fiber to the mixture (A),
Mixing the thermosetting resin and the inorganic particles in at least one of the step (I-1) and the step (I-2),
A method for manufacturing a structure for manufacturing a casting according to claim 1 . In the step (I),
A step (I-1) of obtaining a mixture (A) containing organic fibers and water,
A step (I-2-1) of obtaining a mixture (B) by mixing the mixture (A) with a thermosetting resin and inorganic particles; and
A step (I-2-2) of mixing the mixture (B) with a surfactant having cationic nitrogen or a polymer having cationic nitrogen, and then mixing inorganic fibers.
The method for producing a structure for producing a casting according to claim 1 or 2, further comprising : The content of the inorganic fibers for casting structure in the respect for casting structure 100 parts by mass, not more than 1 part by mass or more 6 parts by weight, according to any one of claims 1 to 3 A method for manufacturing a structure for manufacturing a casting. A polymer having a surfactant or cationic nitrogen having a cationic nitrogen, the organic fibers, mixed 0.1 wt% to 25 wt% or less, producing castings of any one of claims 1-4 Of manufacturing structure for automobile. The method for producing a structure for producing a casting according to any one of claims 1 to 5, further comprising obtaining a slurry composition containing an anionic compound in the step (I). A method for manufacturing a casting, which uses the structure for manufacturing a casting obtained by the method for manufacturing a structure for manufacturing a casting according to claim 1. Casting structure having step (I) for obtaining a slurry composition containing organic fiber, inorganic fiber, inorganic particles, thermosetting resin, cationic nitrogen-containing surfactant or cationic nitrogen-containing polymer, and water A method for producing a body slurry , comprising:
In the step (I), water, organic fibers, and a surfactant having cationic nitrogen or a polymer having cationic nitrogen are mixed, and then inorganic fibers are mixed to obtain the slurry composition,
A method for producing a slurry for a casting manufacturing structure . The step (I) is a step (I-1) of obtaining a mixture (A) containing organic fibers and water, and a surfactant having a cationic nitrogen or a polymer having a cationic nitrogen in the mixture (A). And a step (I-2) of adding an inorganic fiber,
In the step (I-2), a surfactant having a cationic nitrogen is added to the mixture (A) before adding the inorganic fiber to the mixture (A),
Mixing the thermosetting resin and the inorganic particles in at least one of the step (I-1) and the step (I-2),
A method for producing the slurry for a structure for producing a casting according to claim 8 . In the step (I),
A step (I-1) of obtaining a mixture (A) containing organic fibers and water,
A step (I-2-1) of obtaining a mixture (B) by mixing the mixture (A) with a thermosetting resin and inorganic particles; and
A step (I-2-2) of mixing the mixture (B) with a surfactant having cationic nitrogen or a polymer having cationic nitrogen, and then mixing inorganic fibers.
The method for producing a slurry for a structure for producing a casting according to claim 8 , which comprises: The casting production according to any one of claims 8 to 10 , wherein a surfactant having cationic nitrogen or a polymer having cationic nitrogen is mixed in an amount of 0.1% by mass or more and 25% by mass or less with respect to the organic fiber. Method for producing slurry for structural body. The method for producing a slurry for casting structure according to any one of claims 8 to 11 , further comprising obtaining a slurry composition containing an anionic compound in the step (I).