EP4286072A1 - Sable enduit inorganique - Google Patents

Sable enduit inorganique Download PDF

Info

Publication number
EP4286072A1
EP4286072A1 EP22745685.2A EP22745685A EP4286072A1 EP 4286072 A1 EP4286072 A1 EP 4286072A1 EP 22745685 A EP22745685 A EP 22745685A EP 4286072 A1 EP4286072 A1 EP 4286072A1
Authority
EP
European Patent Office
Prior art keywords
mass
parts
inorganic
inorganic binder
coated sand
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Pending
Application number
EP22745685.2A
Other languages
German (de)
English (en)
Other versions
EP4286072A4 (fr
Inventor
Hiroaki Aonuma
Keisuke Nakane
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Kao Corp
Original Assignee
Kao Corp
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Kao Corp filed Critical Kao Corp
Publication of EP4286072A1 publication Critical patent/EP4286072A1/fr
Publication of EP4286072A4 publication Critical patent/EP4286072A4/fr
Pending legal-status Critical Current

Links

Images

Classifications

    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B22—CASTING; POWDER METALLURGY
    • B22C—FOUNDRY MOULDING
    • B22C1/00—Compositions of refractory mould or core materials; Grain structures thereof; Chemical or physical features in the formation or manufacture of moulds
    • B22C1/16—Compositions of refractory mould or core materials; Grain structures thereof; Chemical or physical features in the formation or manufacture of moulds characterised by the use of binding agents; Mixtures of binding agents
    • B22C1/18—Compositions of refractory mould or core materials; Grain structures thereof; Chemical or physical features in the formation or manufacture of moulds characterised by the use of binding agents; Mixtures of binding agents of inorganic agents
    • B22C1/186—Compositions of refractory mould or core materials; Grain structures thereof; Chemical or physical features in the formation or manufacture of moulds characterised by the use of binding agents; Mixtures of binding agents of inorganic agents contaming ammonium or metal silicates, silica sols
    • B22C1/188—Alkali metal silicates
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B22—CASTING; POWDER METALLURGY
    • B22C—FOUNDRY MOULDING
    • B22C1/00—Compositions of refractory mould or core materials; Grain structures thereof; Chemical or physical features in the formation or manufacture of moulds
    • B22C1/02—Compositions of refractory mould or core materials; Grain structures thereof; Chemical or physical features in the formation or manufacture of moulds characterised by additives for special purposes, e.g. indicators, breakdown additives
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B22—CASTING; POWDER METALLURGY
    • B22C—FOUNDRY MOULDING
    • B22C1/00—Compositions of refractory mould or core materials; Grain structures thereof; Chemical or physical features in the formation or manufacture of moulds
    • B22C1/02—Compositions of refractory mould or core materials; Grain structures thereof; Chemical or physical features in the formation or manufacture of moulds characterised by additives for special purposes, e.g. indicators, breakdown additives
    • B22C1/10—Compositions of refractory mould or core materials; Grain structures thereof; Chemical or physical features in the formation or manufacture of moulds characterised by additives for special purposes, e.g. indicators, breakdown additives for influencing the hardening tendency of the mould material
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B22—CASTING; POWDER METALLURGY
    • B22C—FOUNDRY MOULDING
    • B22C1/00—Compositions of refractory mould or core materials; Grain structures thereof; Chemical or physical features in the formation or manufacture of moulds
    • B22C1/16—Compositions of refractory mould or core materials; Grain structures thereof; Chemical or physical features in the formation or manufacture of moulds characterised by the use of binding agents; Mixtures of binding agents
    • B22C1/18—Compositions of refractory mould or core materials; Grain structures thereof; Chemical or physical features in the formation or manufacture of moulds characterised by the use of binding agents; Mixtures of binding agents of inorganic agents

Definitions

  • the present invention relates to inorganic coated sand.
  • the mold obtained by using an inorganic coated sand having a refractory aggregate and an inorganic binder layer formed on the surface of the refractory aggregate to mold the desired shape is known.
  • Patent Document 1 Japanese Unexamined Patent Publication No.2014-117740
  • Patent Document 2 Pamphlet of International Publication No. WO2015/194550
  • Patent Document 1 a production method related to a dry coated sand having normal temperature fluidity which is made by blending a specific water glass aqueous solution as a binder with a heated refractory aggregate and evaporating moisture to form a coating layer of the binder on the surface of the refractory aggregate is described.
  • Patent Document 2 a production method for a casting mold, in which a molding material mixture containing at least a refractory aggregate, a binder including a water glass as an essential component, and a carbonate and/or a borate is filled and held within a forming mold heated to a specific temperature, and thus the molding material mixture is cured.
  • the inorganic binder layer contains one or more selected from zinc oxide and magnesium oxide, and the total content of the zinc oxide and the magnesium oxide is 6 parts by mass or more and 70 parts by mass or less with respect to 100 parts by mass of the inorganic binder.
  • an inorganic coated sand having a refractory aggregate and an inorganic binder layer formed on the surface of the refractory aggregate, in which the inorganic binder layer contains one or more selected from zinc oxide and magnesium oxide, and the total content of the zinc oxide and the magnesium oxide is 6 parts by mass or more and 70 parts by mass or less with respect to 100 parts by mass of the inorganic binder.
  • FIG. 1 A cross-sectional view for explaining a measurement method for deformation of the casting mold in Examples.
  • the present invention provides a method for reducing deformation of a casting mold during casting in the casting mold prepared using an inorganic coated sand.
  • the present invention provides an inorganic coated sand that reduces deformation of the casting mold occurring during casting.
  • the present inventors found that in a casting mold prepared using an inorganic coated sand having a refractory aggregate and an inorganic binder layer formed on the surface of the refractory aggregate, the deformation of the casting mold during casting can be reduced by containing zinc oxide or magnesium oxide in the inorganic binder layer.
  • the present invention it is possible to provide a method for reducing deformation of a casting mold during casting in a casting mold prepared using an inorganic coated sand.
  • the method for reducing deformation of the casting mold during casting is a method in which in the casting mold prepared using an inorganic coated sand having a refractory aggregate and an inorganic binder layer formed on the surface of the refractory aggregate, the inorganic binder layer contains one or more selected from zinc oxide and magnesium oxide, and the total content of zinc oxide and magnesium oxide is 6 parts by mass or more and 70 parts by mass or less with respect to 100 parts by mass of the inorganic binder, specifically with respect to 100 parts by mass of the solid content of the inorganic binder.
  • the reason why the effect of reducing the deformation of the casting mold is exhibited is not clear, but it is considered as follows.
  • the inorganic binder contains alkali silicate or alkali metasilicate as an example
  • by containing a specific amount of zinc oxide or magnesium oxide in the inorganic binder layer of the inorganic coated sand to, for example, form a salt of zinc oxide or magnesium oxide with alkali metal ions of alkali silicate or alkali metasilicate alkali metal ions that inhibit cross-linking of silicate chains is released to outside of the system to promote cross-linking of silicate chains and to consolidate the silicate network.
  • the softening point of the inorganic binder rises, and it is thought that deformation due to the softening of the inorganic binder is less likely to occur even in a case where the casting mold is exposed to the heat of the molten metal.
  • the inorganic coated sand has a refractory aggregate and an inorganic binder layer formed on the surface of the refractory aggregate.
  • the inorganic binder layer contains one or more selected from zinc oxide and magnesium oxide.
  • the total content of zinc oxide and magnesium oxide is 6 parts by mass or more and 70 parts by mass or less with respect to 100 parts by mass of the inorganic binder, specifically with respect to 100 parts by mass of the solid content of the inorganic binder.
  • the inorganic coated sand is specifically composed of inorganic coated sand particle groups
  • the refractory aggregate is specifically composed of refractory aggregate particle groups.
  • the inorganic coated sand is preferably spherical from the viewpoint of improving the fluidity and further improving the fillability into the molding die.
  • the spherical inorganic coated sand means that the inorganic coated sand has a round shape like a ball.
  • the sphericity of the inorganic coated sand is preferably 0.75 or more, more preferably 0.80 or more, and still more preferably 0.82 or more from the viewpoint of improving fluidity, casting mold quality, and casting mold strength, and from the viewpoint of ease of molding the casting mold.
  • the upper limit of the sphericity is specifically 1 or less.
  • the sphericity of the inorganic coated sand can be determined by performing image analysis of a particle image (photograph) obtained by an optical microscope or a digital scope (for example, VH-8000 manufactured by KEYENCE CORPORATION) to obtain the particle projected sectional area of particles and the perimeter of the cross section, then to calculate [the circumferential length of a perfect circle (mm) having the same area as the particle projected sectional area (mm 2 )]/[the perimeter of the particle projected cross section (mm)] for each of any 50 particles, and averaging these values.
  • a particle image photograph
  • a digital scope for example, VH-8000 manufactured by KEYENCE CORPORATION
  • the average particle diameter of the inorganic coated sand is preferably 0.05 mm or more and more preferably 0.1 mm or more from the viewpoint of improving casting mold quality and casting mold strength and from the viewpoint of ease of molding the casting mold.
  • the average particle diameter of the inorganic coated sand is preferably 2 mm or less, more preferably 1 mm or less, and still more preferably 0.5 mm or less from the viewpoint improving casting mold quality and casting mold strength and from the viewpoint of ease of molding the casting mold.
  • the average particle diameter of the inorganic coated sand and the later-described refractory aggregate may be specifically measured by the following method.
  • the diameter (mm) is measured, while in a case where the sphericity ⁇ 1, the major axis diameter (mm) and minor axis diameter (mm) of the randomly oriented particle are measured to obtain (major axis diameter + minor axis diameter)/2.
  • the obtained values are averaged to obtain the average particle diameter (mm).
  • the major axis diameter and minor axis diameter are defined as follows.
  • the width of the particle at which the distance between the parallel lines is the smallest is referred to as the minor axis diameter
  • the length of a particle between two parallel lines perpendicular to the parallel lines is referred to as the major axis diameter.
  • the major axis diameter and minor axis diameter of the particles are obtained by taking an image (photograph) of the particles with an optical microscope or a digital scope (for example, VH-8000 manufactured by KEYENCE CORPORATION) and analyzing the obtained image.
  • Examples of materials for the refractory aggregate include one or more selected from the group consisting of natural sand and artificial sand.
  • natural sand examples include one or two or more selected from the group consisting of silica sand containing quartz as a main component, chromite sand, zircon sand, olivine sand, and alumina sand.
  • artificial sand examples include one or two or more selected from the group consisting of synthetic mullite sand, SiO 2 -based casting sand containing SiO 2 as a main component, Al 2 O 3 -based casting sand containing Al 2 O 3 as a main component, SiO 2 /Al 2 O 3 -based casting sand, SiO 2 /MgO-based casting sand, SiO 2 /Al 2 O 3 /ZrO 2 -based casting sand, SiO 2 /Al 2 O 3 /Fe 2 O 3 -based casting sand, and slag-derived casting sand.
  • the main component means the most abundant component among the components contained in sand.
  • the artificial sand is not casting sand produced from nature, but casting sand obtained by artificially preparing a metal oxide component and melting or sintering.
  • recovered sand obtained by recovering used refractory aggregates and recycled sand obtained by subjecting recovered sand to recycling treatment may also be used.
  • the refractory aggregate is preferably in the form of particles from the viewpoint of improving the fluidity of the inorganic coated sand and further improving the fillability into the molding die.
  • the average particle diameter of the refractory aggregate is preferably 0.05 mm or more and more preferably 0.1 mm or more from the viewpoint of improving casting mold quality and casting mold strength and from the viewpoint of ease of molding the casting mold.
  • the used amount of the inorganic binder layer can be reduced during the production of the casting mold and thus the inorganic coated sand is more easily recycled.
  • the average particle diameter of the refractory aggregate is preferably 2 mm or less, more preferably 1 mm or less, and still more preferably 0.5 mm or less from the viewpoint improving casting mold quality and casting mold strength and from the viewpoint of ease of molding the casting mold.
  • the inorganic binder layer specifically contains an inorganic binder and one or more selected from zinc oxide and magnesium oxide.
  • the inorganic binder layer is specifically a coating layer formed on the surface of the refractory aggregate.
  • the inorganic binder layer may be, for example, a layer coated with a mixture of an inorganic binder and one or more selected from zinc oxide and magnesium oxide; a layer further coated with one or more selected from zinc oxide and magnesium oxide on the layer coated with the inorganic binder; or a layer further coated with one or more compounds selected from zinc oxide and magnesium oxide on the layer coated with a mixture of the inorganic binder and one or more compounds selected from zinc oxide and magnesium oxide.
  • the content of the inorganic binder layer in the inorganic coated sand is preferably 0.05% by mass or more, more preferably 0.1% by mass or more, still more preferably 0.5% by mass or more, even still more preferably 1.0% by mass or more, and especially preferably 1.5% by mass or more with respect to the whole components excluding water in the inorganic coated sand.
  • the content of the inorganic binder layer in the inorganic coated sand is preferably 10% by mass or less, more preferably 8% by mass or less, still more preferably 6% by mass or less, even still more preferably 4.5% by mass or less, and yet even still more preferably 4% by mass or less with respect to the whole components excluding water in the inorganic coated sand.
  • the content of the inorganic binder layer refers to the content excluding water contained in the inorganic binder layer.
  • the content is calculated in terms of sodium metasilicate.
  • the content of the inorganic binder layer in the inorganic coated sand is preferably 0.05 parts by mass or more, more preferably 0.1 parts by mass or more, still more preferably 0.5 parts by mass or more, even still more preferably 1 part by mass or more, and especially preferably 1.5 parts by mass or more with respect to 100 parts by mass of the refractory aggregate.
  • the content of the inorganic binder layer in the inorganic coated sand is preferably 10 parts by mass or less, more preferably 8 parts by mass or less, still more preferably 6 parts by mass or less, even still more preferably 4.5 parts by mass or less, and yet even still more preferably 4 parts by mass or less with respect to 100 parts by mass of the refractory aggregate.
  • the inorganic binder contains, for example, a silicic acid compound, and preferably at least one selected from sodium silicate and sodium metasilicate.
  • the inorganic binder may further contain a compound in which a water-soluble silicic acid compound other than the above is contained as a main component.
  • silicic acid compound other than sodium silicate and sodium metasilicate include potassium silicate, potassium metasilicate, lithium silicate, and ammonium silicate.
  • sodium silicate examples include one or two or more selected from the group consisting of sodium silicates Nos. 1 to 5.
  • sodium silicate is classified into Nos. 1 to 5 according to the molar ratio of SiO 2 /Na 2 O, and sodium silicates Nos. 1 to 3 are prescribed in JIS-K-1408.
  • the molar ratio of SiO 2 /Na 2 O in each sodium silicate is as follows.
  • the molar ratio of SiO 2 /Na 2 O may be adjusted to a desired degree.
  • Sodium silicate is preferably at least one selected from No. 1 water glass and No. 3 water glass.
  • Sodium metasilicate is preferably a hydrate from the viewpoint of improving the productivity of the inorganic coated sand and the viewpoint of improving the productivity of the casting mold.
  • the sodium metasilicate hydrate is preferably at least one selected from sodium metasilicate pentahydrate and sodium metasilicate nonahydrate, and more preferably sodium metasilicate nonahydrate.
  • the content of the inorganic binder in the inorganic binder layer is preferably 25% by mass or more, more preferably 30% by mass or more, still more preferably 35% by mass or more, and even still more preferably 40% by mass or more with respect to the whole inorganic binder layer.
  • the content of the inorganic binder in the inorganic binder layer is preferably 94% by mass or less and more preferably 93% by mass or less with respect to the whole inorganic binder layer.
  • the content of the inorganic binder in the inorganic binder layer refers to the content of the inorganic binder excluding moisture with respect to the whole components excluding water in the inorganic binder layer.
  • the total content of sodium silicate and sodium metasilicate in the inorganic binder is preferably 80% by mass or more, more preferably 90% by mass or more, still more preferably 95% by mass or more, even still more preferably 98% by mass or more, and yet even still more preferably substantially 100% by mass.
  • the term "substantially” means that unintentionally contained components, for example, components other than sodium silicate and sodium metasilicate contained in sodium silicate and sodium metasilicate which are raw materials, may be contained.
  • the total content of sodium silicate and sodium metasilicate in the inorganic binder refers to the total content of sodium silicate and sodium metasilicate with respect to whole components excluding water in the inorganic binder.
  • the content of the inorganic binder in the inorganic coated sand is preferably 0.03 parts by mass or more, more preferably 0.1 parts by mass or more, still more preferably 0.5 parts by mass or more, even still more preferably 0.8 parts by mass or more, and especially preferably 1 part by mass or more with respect to 100 parts by mass of the refractory aggregate.
  • the content of the inorganic binder in the inorganic coated sand is preferably 5 parts by mass or less, more preferably 4 parts by mass or less, still more preferably 3 parts by mass or less, and even still more preferably 2 parts by mass or less with respect to 100 parts by mass of the refractory aggregate.
  • the properties of zinc oxide (ZnO) and magnesium oxide (MgO) are preferably fine particles from the viewpoint of enhancing reactivity with the inorganic binder.
  • the average particle diameters of zinc oxide and magnesium oxide are preferably 100 um or less, more preferably 50 um or less, still more preferably 30 um or less, even still more preferably 20 um or less, and yet even still more preferably 15 um or less.
  • the average particle diameters of zinc oxide and magnesium oxide is preferably 0.1 um or more, more preferably 0.3 um or more, still more preferably 0.5 um or more, and even still more preferably 1 um or more.
  • the average particle diameters of zinc oxide and magnesium oxide may be performed using the following measurement method.
  • the average particle diameter is 50% volume cumulative particle diameter measured using a laser diffraction particle size distribution measuring device LA-960V2 (manufactured by HORIBA, Ltd.). Analysis conditions are as follows.
  • the total content of zinc oxide and magnesium oxide in the inorganic binder layer is preferably 2% by mass or more and more preferably 3% by mass or more with respect to whole components excluding water in the inorganic binder layer.
  • the total content of zinc oxide and magnesium oxide in the inorganic binder layer is preferably 45% by mass or less, more preferably 40% by mass or less, and still more preferably 35% by mass or less with respect to the whole components excluding water in the inorganic binder layer.
  • the total content of zinc oxide and magnesium oxide with respect to 100 parts by mass of the inorganic binder is preferably 6 parts by mass or more, more preferably 7 parts by mass or more, still more preferably 10 parts by mass or more, even still more preferably 15 parts by mass or more, and especially preferably 20 parts by mass or more.
  • the total content of zinc oxide and magnesium oxide with respect to 100 parts by mass of the inorganic binder is preferably 70 parts by mass or less, more preferably 60 parts by mass or less, still more preferably 55 parts by mass or less, and even still more preferably 50 parts by mass or less.
  • the inorganic binder layer may contain various additives as necessary.
  • additives include moisturizing agents, moisture resistance improvers, coupling agents that strengthen the bond between the refractory aggregate and the inorganic binder, lubricants, surfactants, releasing agents.
  • moisturizing agents include polyhydric alcohols, water-soluble polymers, hydrocarbons, sugars, proteins, and inorganic compounds other than those mentioned above.
  • moisture resistance improvers include metal oxides (excluding zinc oxide and magnesium oxide), carbonates, borates, sulfates, phosphates.
  • lubricants include waxes; fatty acid amides; alkylene fatty acid amides; stearic acid; stearyl alcohol; metal stearates such as lead stearate, zinc stearate, calcium stearate, and magnesium stearate; monoglyceride stearate; stearyl stearate; hydrogenated oil.
  • releasing agents include paraffin, wax, light oil, machine oil, spindle oil, insulating oil, waste oil, vegetable oil, fatty acid ester, organic acid, graphite fine particles, mica, vermiculite, fluorine-based releasing agent, and silicone-based releasing agent.
  • the inorganic coated sand may further contain inorganic fine particles excluding zinc oxide and magnesium oxide.
  • the inorganic fine particles preferably form part of the inorganic binder layer.
  • the inorganic binder layer preferably further contains inorganic fine particles at least one of on the layer and in the layer, and more preferably further contains inorganic fine particles on the layer.
  • the inorganic fine particles may be contained both on the inorganic binder layer and in the inorganic binder layer.
  • the particles of the inorganic coated sand are more firmly bound to each other through the inorganic fine particles, and as a result, the strength of the obtained casting mold can be further improved.
  • the inorganic fine particles on the inorganic binder layer may be partially embedded in the inorganic binder layer.
  • inorganic fine particles include, but are not limited to, silica particles and silicon particles. From the viewpoint of improving the strength of the casting mold, silica particles are preferable, and from the viewpoint of having a large specific surface area and being highly reactive with sodium silicate and sodium metasilicate, amorphous silica particles are more preferable. These inorganic fine particles may be used singly or may be used in combination of two or more.
  • the inorganic coated sand may further contain amorphous silica particles.
  • Amorphous silica particles preferably form part of the inorganic binder layer.
  • the amorphous degree of the amorphous silica particles is preferably 80% or more, more preferably 90% or more, still more preferably 93% or more, even still more preferably 95% or more, and especially preferably 98% or more.
  • the upper limit of the amorphous degree of the amorphous silica particles is not limited, but is, for example, 100% or less, may be 99.8% or less, and also may be 99% or less.
  • the amorphous degree of amorphous silica particles may be obtained by the X-ray diffraction method shown below.
  • Amorphous silica particles are pulverized in a mortar and pressed against an X-ray glass holder of a powder X-ray diffractometer for measurement.
  • the average particle diameter d 50 in the weight-based particle size distribution of amorphous silica particles by a laser diffraction scattering particle size distribution measurement method is preferably 0.1 um or more and more preferably 0.3 um or more. Further, from the viewpoint of improving the strength of the casting mold, the above-described average particle diameter d 50 of the amorphous silica particles is preferably 2.0 um or less, more preferably 1.0 um or less, still more preferably 0.8 um or less, and even still more preferably 0.6 um or less.
  • the average particle diameter d 50 in the weight-based particle size distribution of the amorphous silica particles by the laser diffraction scattering particle size distribution measurement method may be obtained, for example, by dissolving the inorganic binder layer in water to remove it from the inorganic coated sand, collecting the amorphous silica particles, and then measuring the particle size of the obtained amorphous silica particles by a laser diffraction scattering particle size distribution measurement method.
  • the average particle diameter d 50 in the weight-based particle size distribution of the amorphous silica particles by the laser diffraction scattering particle size distribution measurement method may also be obtained by measuring the particle size of the amorphous silica particles as a raw material by the laser diffraction scattering particle size distribution measurement method.
  • the average particle diameter of the amorphous silica particles obtained from the observation image of the scanning electron microscope is preferably 0.1 um or more and more preferably 0.3 um or more.
  • the average particle diameter of the amorphous silica particles obtained from the observation image of the scanning electron microscope is preferably 2.0 um or less, more preferably 1.0 um or less, still more preferably 0.8 um or less, and even still more preferably 0.6 um or less.
  • Random particle sorting may be performed as a pretreatment. For example, after determining the inorganic binder layer and the amorphous silica particles based on the elements, 100 arbitrary amorphous silica particles are selected, their particle diameters are measured, and the average particle diameter of 80 amorphous silica particles excluding a total of 20 amorphous silica particles of 10 particles counted from the maximum particle diameter and 10 particles counted from the minimum particle diameter may be the average particle diameter of the amorphous silica particles.
  • the content of the amorphous silica particles in the inorganic binder layer is specifically 0% by mass or more, preferably 20% by mass or more, more preferably 25% by mass or more, and still more preferably 30% by mass or more with respect to the whole components excluding water in the inorganic binder layer.
  • the content of the amorphous silica particles in the inorganic binder layer is preferably 55% by mass or less, more preferably 50% by mass or less, and still more preferably 45% by mass or less with respect to the whole components excluding water in the inorganic binder layer.
  • the content of the amorphous silica particles is specifically 0 parts by mass or more, preferably 20 parts by mass or more, more preferably 40 parts by mass or more, still more preferably 50 parts by mass or more, and even still more preferably 60 parts by mass or more with respect to 100 parts by mass of the inorganic binder.
  • the content of the amorphous silica particles is preferably 150 parts by mass or less, more preferably 120 parts by mass or less, still more preferably 100 parts by mass or less, even still more preferably 90 parts by mass or less, and yet even still more preferably 80 parts by mass or less with respect to 100 parts by mass of the inorganic binder.
  • the content of water in the inorganic binder layer contained in the inorganic coated sand is preferably 5 parts by mass or more, more preferably 10 parts by mass or more, and still more preferably 20 parts by mass or more with respect to 100 parts by mass of the inorganic binder.
  • the content of water in the inorganic binder layer contained in the inorganic coated sand is preferably 180 parts by mass or less, more preferably 160 parts by mass or less, still more preferably 150 parts by mass or less, and even still more preferably 140 parts by mass or less with respect to 100 parts by mass of the inorganic binder.
  • the content of water in the inorganic binder layer contained in the inorganic coated sand may be adjusted according to the type of inorganic binder.
  • the content of water in the inorganic binder layer is preferably 5 parts by mass or more, more preferably 10 parts by mass or more, and still more preferably 20 parts by mass or more with respect to 100 parts by mass of sodium silicate.
  • the content of water in the inorganic binder layer contained in the inorganic coated sand is preferably 55 parts by mass or less and more preferably 50 parts by mass or less with respect to 100 parts by mass of sodium silicate.
  • the content of water in the inorganic binder layer is preferably 60 parts by mass or more, more preferably 65 parts by mass or more, still more preferably 90 parts by mass or more, and even still more preferably 110 parts by mass or more with respect to 100 parts by mass of sodium metasilicate, and from the viewpoint of improving fluidity and further improving the fillability into the molding die, the content of water in the inorganic binder layer is preferably 180 parts by mass or less, more preferably 160 parts by mass or less, still more preferably 150 parts by mass or less, and even still more preferably 140 parts by mass or less with respect to 100 parts by mass of sodium metasilicate.
  • the content of water is 74 parts by mass with respect to 100 parts by mass of sodium metasilicate, and in a case where it is only sodium metasilicate nonahydrate, the content of water is 133 parts by mass with respect to 100 parts by mass of sodium metasilicate.
  • the method for producing the inorganic coated sand may be selected, for example, according to the type of inorganic binder.
  • a dry inorganic coated sand having normal temperature fluidity can be obtained by, for example, kneading or mixing a water glass aqueous solution as the inorganic binder with the heated refractory aggregate, together with additives as necessary to blend uniformly, coating the surface of the refractory aggregate with the water glass aqueous solution, and allowing the moisture in the water glass aqueous solution to being evaporated.
  • a dry inorganic coated sand can be obtained by a production method including, for example, mixing the refractory aggregate and the sodium metasilicate hydrate at a temperature not less than the melting point of the sodium metasilicate hydrate to obtain a mixture; and cooling the mixture to a temperature less than the melting point of the sodium metasilicate hydrate.
  • the inorganic binder layer can be crystallized, thus an inorganic coated sand having excellent fluidity can be obtained as compared with the conventional production method.
  • a dehydration step is not needed, and the production method for the inorganic coated sand can be simplified.
  • the surface of the refractory aggregate is coated with the fluidized sodium metasilicate hydrate at a temperature not less than the melting point of the sodium metasilicate hydrate.
  • Examples of the method of mixing the refractory aggregate and the sodium metasilicate hydrate at a temperature not less than the melting point of the sodium metasilicate hydrate include a method of adding the sodium metasilicate hydrate to a refractory aggregate heated to a temperature not less than the melting point of the sodium metasilicate hydrate and mixing the refractory aggregate and the sodium metasilicate hydrate while melting the sodium metasilicate hydrate; and a method of adding the heat-melted sodium metasilicate hydrate to the refractory aggregate and mixing them.
  • the method of adding the heat-melted sodium metasilicate hydrate to the refractory aggregate and mixing them is preferable.
  • the obtaining the mixture does not include intentionally adding water.
  • Mixing conditions such as stirring speed and treatment time when the refractory aggregate and sodium metasilicate hydrate are mixed may be appropriately determined according to the treatment amount of the mixture.
  • the fluidity of the sodium metasilicate hydrate is reduced by cooling the mixture obtained in the obtaining the mixture to a temperature less than the melting point of the sodium metasilicate hydrate, the sodium metasilicate hydrate is fixed on the surface of the refractory aggregate, and the sodium metasilicate hydrate layer, that is, the inorganic binder layer is formed.
  • inorganic coated sand there are no restrictions on the method of adding zinc oxide or magnesium oxide, for example, after the refractory aggregate is coated with the inorganic binder, optionally the amorphous silica particles and the above-described other additives, one or more selected from zinc oxide and magnesium oxide, optionally amorphous silica particles and other additives may be coated.
  • the refractory aggregate may be coated together with the inorganic binder and one or more selected from zinc oxide and magnesium oxide, optionally amorphous silica particles and other additives.
  • the refractory aggregate may be coated together with the inorganic binder and one or more selected from zinc oxide and magnesium oxide, optionally amorphous silica particles and other additives, one or more selected from zinc oxide and magnesium oxide, or optionally amorphous silica particles and other additives may be coated.
  • the refractory aggregate is coated with an inorganic binder and then is coated with one or more selected from zinc oxide and magnesium oxide.
  • Zinc oxide or magnesium oxide in solid form or in aqueous dispersion can be mixed with the refractory aggregate, the inorganic binder, and the like.
  • zinc oxide or magnesium oxide may be added all at once, or may be added in a plurality of times.
  • the inorganic coated sand in the present embodiment may be obtained.
  • the obtained inorganic coated sand can be used singly or in combination with other known refractory aggregates or other additives to mold desired casting molds.
  • the casting mold is made by using the inorganic coated sand in the present embodiment described above.
  • the molding method for the casting mold include a molding method using a heated molding die, and a molding method in which water vapor is further passed through the heated molding die and then hot air is passed through the heated molding die.
  • the inorganic binder layer contains sodium metasilicate hydrate
  • a method of molding by filling a heated molding die with inorganic coated sand is preferable.
  • the inorganic binder layer contains sodium silicate
  • the inorganic binder layer contains sodium metasilicate hydrate
  • the inorganic coated sand is first filled into the molding die that provides the desired casting mold.
  • the molding die is preferably heated in advance to keep it warm before filling with the inorganic coated sand.
  • the heating temperature at this time is preferably 100°C or more, and more preferably 150°C or more, and is also preferably 300°C or less and more preferably 250°C or less.
  • the molding die After filling with the inorganic coated sand, the molding die is heated without passage of water vapor to cure the inorganic coated sand.
  • the inorganic binder layer contains sodium metasilicate hydrate
  • the inorganic coated sand can be cured without using adding water to the inorganic coated sand and kneading, or passing water vapor, and thus the equipment or the like for passing water vapor is unnecessary.
  • the heating temperature is preferably 100°C or more, and more preferably 150°C or more, and is also preferably 300°C or less and more preferably 250°C or less.
  • the heating time is preferably 30 seconds or more and more preferably 60 seconds or more, and is also preferably 600 seconds or less.
  • the inorganic binder layer contains sodium silicate
  • water is added to the inorganic coated sand and the inorganic coated sand is kneaded, and then filled into a heated molding die.
  • water vapor is passed through
  • water vapor is blown in after the inorganic coated sand is filled into the molding die that provides the desired casting mold.
  • the passage of water vapor wets the filled phase of the inorganic coated sand to be in a wet state.
  • hot air is passed through the molding die heated to 90°C to 200°C to dry and cure the inorganic coated sand.
  • the inorganic coated sand in the present embodiment may also be used in the laminate molding method.
  • the present invention further discloses a method for reducing deformation of a casting mold, and an inorganic coated sand described below.
  • Mikawa Silica Sand R6 (100 parts by mass) was added to a stirrer as a refractory aggregate. Next, sodium metasilicate nonahydrate (4.00 parts by mass) melted by heating to 80°C was added to the stirrer and kneaded for 4 minutes, and then amorphous silica fine particles (1.20 parts by mass) were added thereto and kneaded for 2 minutes. Then, zinc oxide or magnesium oxide in the amount shown in Table 1 was added thereto and kneaded for 2 minutes to obtain inorganic coated sands of Examples 1 to 4. Table 1 shows a blending composition of the inorganic coated sand.
  • Mikawa Silica Sand R6 (100 parts by mass) heated to about 120°C was added to a stirrer as a refractory aggregate.
  • No. 1 50 water glass (4.00 parts by mass) was put into a stirrer and kneaded to evaporate moisture, and stirred for about 3 minutes until the sand grain lumps collapsed.
  • zinc oxide or magnesium oxide (the amount shown in Table 2) was added thereto and kneaded for 2 minutes to obtain inorganic coated sands of Examples 5 to 12.
  • Table 2 shows a blending composition of the inorganic coated sand.
  • Mikawa Silica Sand R6 (100 parts by mass) heated to about 120°C was added to a stirrer as a refractory aggregate. Next, No. 3 water glass (4.00 parts by mass) and zinc oxide or magnesium oxide (0.41 parts by mass) was put into a stirrer and kneaded to evaporate moisture, and stirred for about 3 minutes until the sand grain lumps collapsed and to obtain the inorganic coated sands of Examples 14 and 16. Table 3 shows a blending composition of the inorganic coated sand.
  • Mikawa Silica Sand R6 (100 parts by mass) heated to about 120°C was added to a stirrer as a refractory aggregate. Next, No. 3 water glass (4.00 parts by mass) was put into a stirrer and kneaded to evaporate moisture, and stirred for about 3 minutes until the sand grain lumps collapsed. Furthermore, zinc oxide or magnesium oxide (0.41 parts by mass) was added thereto and kneaded for 2 minutes to obtain inorganic coated sands of Examples 15 and 17.
  • the inorganic coated sand of Comparative Example 1 was obtained in the same manner as in Examples 1 to 4, except that neither zinc oxide nor magnesium oxide was added.
  • Table 1 shows a blending composition of the inorganic coated sand.
  • the inorganic coated sand of Comparative Example 2 was obtained in the same manner as in Examples 5 to 12, except that neither zinc oxide nor magnesium oxide was added.
  • Table 2 shows a blending composition of the inorganic coated sand.
  • the inorganic coated sand of Comparative Example 3 was obtained in the same manner as in Example 13, except that zinc oxide was not added.
  • Table 2 shows a blending composition of the inorganic coated sand.
  • the inorganic coated sand of Comparative Example 4 was obtained in the same manner as in Examples 14 to 17, except that neither zinc oxide nor magnesium oxide was added.
  • Table 3 shows a blending composition of the inorganic coated sand.
  • a 22.3 ⁇ 22.3 ⁇ 180 mm test piece (5-cavity) mold was heated to 180°C.
  • the inorganic coated sand of each example using a CSR-43 blow molding machine, the inorganic coated sand was filled into the test piece mold at a blow pressure of 0.3 MPa. Then, the inorganic coated sand was allowed to stand for 150 seconds in the molding die to cure it, and a casting mold test piece was obtained.
  • Fig. 1(a) and Fig. 1(b) are cross-sectional views for explaining a measurement method for deformation of the casting mold.
  • the casting mold test piece of each example obtained by the above-described method was left in a thermostatic chamber at 25°C/55 %RH for 1 hour, and then cut into a plate-shaped test piece 10 of 5 ⁇ 22.3 ⁇ 90 mm.
  • Metal pedestals 11a and 11b (13 mm ⁇ 13 mm, height of 13 mm) were arranged on an iron plate of appropriate size such that the distance between the centers was 90 mm, and a plate-shaped test piece 10 was placed on it such that the edges of the plate-shaped test piece 10 were positioned at the centers of the pedestals, respectively ( Fig. 1(a) ).
  • a weight 13 (4.7 g) was placed on the center of the plate-shaped test piece 10. Then, the iron plate on which the plate-shaped test piece 10 was placed was heated in a muffle furnace heated under the conditions described later. After a predetermined time had elapsed, the plate-shaped test piece 10 was taken out from the muffle furnace and allowed to stand for 1 hour to cool. Then, the deformation amount of the plate-shaped test piece 10 was measured. The deformation amount was defined as the maximum vertical distance from the straight line connecting both ends of the plate-shaped test piece 10 to the curved portion ( Fig. 1(b) ).
  • the heating conditions were 500°C and 10 minutes for all of Examples 1 to 17 and Comparative Examples 1 to 4.

Landscapes

  • Engineering & Computer Science (AREA)
  • Chemical & Material Sciences (AREA)
  • Materials Engineering (AREA)
  • Mechanical Engineering (AREA)
  • Mold Materials And Core Materials (AREA)
EP22745685.2A 2021-01-29 2022-01-19 Sable enduit inorganique Pending EP4286072A4 (fr)

Applications Claiming Priority (3)

Application Number Priority Date Filing Date Title
JP2021012896 2021-01-29
JP2021207414 2021-12-21
PCT/JP2022/001786 WO2022163464A1 (fr) 2021-01-29 2022-01-19 Sable enduit inorganique

Publications (2)

Publication Number Publication Date
EP4286072A1 true EP4286072A1 (fr) 2023-12-06
EP4286072A4 EP4286072A4 (fr) 2025-10-29

Family

ID=82653332

Family Applications (1)

Application Number Title Priority Date Filing Date
EP22745685.2A Pending EP4286072A4 (fr) 2021-01-29 2022-01-19 Sable enduit inorganique

Country Status (3)

Country Link
EP (1) EP4286072A4 (fr)
JP (1) JP7853102B2 (fr)
WO (1) WO2022163464A1 (fr)

Family Cites Families (12)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS342257B1 (fr) * 1957-05-10 1959-04-09
JPS5325803B2 (fr) * 1972-03-03 1978-07-28
US3923525A (en) * 1973-04-17 1975-12-02 Ashland Oil Inc Foundry compositions
JP4209286B2 (ja) * 2003-08-19 2009-01-14 トヨタ自動車株式会社 高強度水溶性中子、及びその製造方法
DE102004042535B4 (de) * 2004-09-02 2019-05-29 Ask Chemicals Gmbh Formstoffmischung zur Herstellung von Gießformen für die Metallverarbeitung, Verfahren und Verwendung
DE102006049379A1 (de) * 2006-10-19 2008-04-24 Ashland-Südchemie-Kernfest GmbH Phosphorhaltige Formstoffmischung zur Herstellung von Giessformen für die Metallverarbeitung
EP2163328A1 (fr) 2008-09-05 2010-03-17 Minelco GmbH Sable de noyau ou de moule revêtu par et/ou mélangés avec des silicates de potassium ayant une teneur en eau comprise entre environ 0,25 poids -% jusqu'à environ 0,9 poids -%
JP5986498B2 (ja) 2012-12-19 2016-09-06 旭有機材株式会社 コーテッドサンドの製造方法及び鋳型の製造方法
CN103231010A (zh) 2013-04-16 2013-08-07 繁昌县恒鑫汽车零部件有限公司 易溃散型覆膜砂
EP3159073B1 (fr) 2014-06-20 2023-04-05 Asahi Yukizai Corporation Procédé de fabrication de moule et moule
KR101614401B1 (ko) 2015-03-10 2016-04-21 (주)피알테크 주물사용 무기 바인더 조성물
CN110918883A (zh) * 2019-12-19 2020-03-27 华中科技大学 一种基于三维喷印的铸造砂型及其成形方法

Also Published As

Publication number Publication date
JP2022117455A (ja) 2022-08-10
JP7853102B2 (ja) 2026-04-28
EP4286072A4 (fr) 2025-10-29
WO2022163464A1 (fr) 2022-08-04

Similar Documents

Publication Publication Date Title
EP3821997B1 (fr) Sable enrobé inorganique et son procédé de fabrication, moule de coulée et son procédé de fabrication
JP7122977B2 (ja) 鋳型材料組成物及びこれを用いた鋳型の製造方法
JP2016523183A (ja) 金属鋳造用の鋳型及び中子を製造するための無機バインダに基づくリチウム含有鋳型材料混合物の製造方法、リチウム含有無機バインダ、及び、鋳造用鋳型又は中子の製造方法
DE102012020510A1 (de) Formstoffmischungen auf der Basis anorganischer Bindemittel und Verfahren zur Herstellung von Formen und Kerne für den Metallguss
CN106470779A (zh) 含甲阶酚醛树脂和无定形二氧化硅的模制材料混合物、由其制成的模具和型芯及其制造方法
CN114929410B (zh) 无机覆膜砂
EP4286072A1 (fr) Sable enduit inorganique
JP2024018294A (ja) 無機コーテッドサンドおよびその製造方法、ならびに無機コーテッドサンドの保存安定性向上方法
US11975382B2 (en) Use of a particulate material comprising a particle-shaped synthetic amorphic silicon dioxide as an additive for a molding material mixture, corresponding method, mixtures, and kits
EP4342600A1 (fr) Sable revêtu inorganique
JP7537964B2 (ja) 鋳型造型用組成物
JP2024018288A (ja) 無機コーテッドサンドおよびその製造方法、ならびに無機コーテッドサンドの保存安定性向上方法
CN116801998A (zh) 无机覆膜砂
JP7490626B2 (ja) 無機コーテッドサンド
JP2024017308A (ja) 無機コーテッドサンドおよびその製造方法
CN117295569A (zh) 无机覆膜砂
JP2025034473A (ja) 無機コーテッドサンドの製造方法および鋳造用鋳型の製造方法
CN121263260A (zh) 无机覆膜砂及其制造方法、无机覆膜砂组合物以及铸造用铸型
JP2025033496A (ja) 無機コーテッドサンドの製造方法、および鋳型の製造方法
WO2024253166A1 (fr) Sable revêtu de matière inorganique, son procédé de production, composition de sable revêtu de matière inorganique et moule de coulée
EP4711056A1 (fr) Sable de fonderie pour moule ainsi que procédé de fabrication de celui-ci, et procédé d'amélioration de stabilité de conservation de sable de fonderie pour moule
EP4711055A1 (fr) Sable enrobé inorganique ainsi que procédé de fabrication de celui-ci, moule pour coulée, et procédé d'amélioration de stabilité de conservation de sable enrobé inorganique
JP2025098412A (ja) 無機コーテッドサンドおよび無機コーテッドサンドの製造方法
WO2026028892A1 (fr) Procédé de production de sable enrobé

Legal Events

Date Code Title Description
STAA Information on the status of an ep patent application or granted ep patent

Free format text: STATUS: THE INTERNATIONAL PUBLICATION HAS BEEN MADE

PUAI Public reference made under article 153(3) epc to a published international application that has entered the european phase

Free format text: ORIGINAL CODE: 0009012

STAA Information on the status of an ep patent application or granted ep patent

Free format text: STATUS: REQUEST FOR EXAMINATION WAS MADE

17P Request for examination filed

Effective date: 20230809

AK Designated contracting states

Kind code of ref document: A1

Designated state(s): AL AT BE BG CH CY CZ DE DK EE ES FI FR GB GR HR HU IE IS IT LI LT LU LV MC MK MT NL NO PL PT RO RS SE SI SK SM TR

DAV Request for validation of the european patent (deleted)
DAX Request for extension of the european patent (deleted)
A4 Supplementary search report drawn up and despatched

Effective date: 20250930

RIC1 Information provided on ipc code assigned before grant

Ipc: B22C 1/10 20060101AFI20250924BHEP

Ipc: B22C 1/18 20060101ALI20250924BHEP

Ipc: B22C 1/02 20060101ALI20250924BHEP