JP2017165621A - Method for producing inorganic filler particle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for producing an inorganic filler particle which allows a resin composition having excellent whiteness to be obtained reliably.SOLUTION: A method for producing an inorganic filler particle includes cleaning a glass particle having a metal particle deposited on its surface, with an acid solution.SELECTED DRAWING: None

Description

  The present invention relates to a method for producing inorganic filler particles suitable for a three-dimensional modeling resin composition.

  Conventionally, a method of obtaining a three-dimensional model by laminating resin materials or the like is known. For example, various methods such as an optical modeling method, a powder bed fusion sintering method, and a hot melt deposition (FDM) method have been proposed and put into practical use (see, for example, Patent Document 1).

  Among them, stereolithography is excellent in detailed modeling and accurate size expression, and is widely used. The stereolithography method is to produce a three-dimensional model as follows. First, a modeling stage is provided in a tank filled with a liquid photocurable resin, and the photocurable resin on the modeling stage is irradiated with an active energy ray such as an ultraviolet laser to form a cured layer having a desired pattern. When one cured layer is formed in this way, the modeling stage is lowered by one layer, an uncured photocurable resin is introduced onto the cured layer, and the active energy rays are irradiated onto the photocurable resin in the same manner. A new hardened layer is stacked on the hardened layer. By repeating this operation, a predetermined three-dimensional model is obtained. In the powder sintering method, a modeling stage is provided in a tank filled with resin, metal, ceramics, or glass powder, and the powder on the modeling stage is irradiated with active energy rays to harden a desired pattern by softening deformation. The layer is formed.

  The three-dimensional structure obtained by the above method is required to have high mechanical strength depending on the application. Patent Document 1 describes that the mechanical strength (mechanical rigidity) of the resulting three-dimensional structure is improved by including inorganic filler particles in the resin composition.

Japanese Patent Laid-Open No. 7-26060

  In recent years, the uses of three-dimensional shaped objects made of resin compositions have been diversified, and are being developed for uses that require aesthetics such as decorative items. Therefore, it has been studied to obtain a three-dimensional structure with higher whiteness by using highly transparent glass particles as the inorganic filler particles. However, even if a three-dimensional model is produced using a resin composition in which glass particles are blended as inorganic filler particles, a three-dimensional model having a desired whiteness may not be obtained.

  In view of the above, an object of the present invention is to provide a method for producing inorganic filler particles capable of reliably obtaining a resin composition having excellent whiteness.

  The method for producing inorganic filler particles of the present invention is characterized in that glass particles having metal particles attached to the surface are washed with an acidic solution.

  As a result of the inventor's investigation, when a three-dimensional object is produced using a resin composition containing glass particles as inorganic filler particles, a three-dimensional object having a desired whiteness cannot be obtained. It was found that this was caused by metal particles adhering to the particle surface as impurities. That is, since the said metal particle absorbs visible light easily, the whiteness of glass particle itself falls. When such glass particles are blended in the resin, the whiteness of the resulting resin composition tends to decrease significantly. In addition, it is thought that a metal particle mixes from a container, an instrument, etc. in the manufacturing process of glass powder, especially a crushing process and a classification process.

  As a result of intensive studies by the present inventor, it was found that inorganic filler particles having high whiteness can be obtained by washing glass particles with an acidic solution. This is because the metal particles adhering to the surface are removed by acid cleaning of the glass particles. Thereby, it becomes possible to improve the whiteness of the resin composition containing the inorganic filler particles made of the glass particles.

  In the method for producing inorganic filler particles of the present invention, the acidic solution preferably has a pH of 6.5 or less. If it does in this way, the metal particle adhering to the surface of glass particle can be removed effectively.

  In the method for producing inorganic filler particles of the present invention, the acidic solution is preferably at least one selected from hydrochloric acid, sulfuric acid and nitric acid.

  In the method for producing inorganic filler particles of the present invention, the metal particles comprise at least one selected from, for example, Fe, Cr and Ni.

  In the method for producing inorganic filler particles of the present invention, the adhesion amount of metal particles is, for example, 300 μg or more with respect to 1 g of glass particles. Thus, when there is much adhesion amount of a metal particle, since the whiteness of an inorganic filler particle will fall easily, it will become easy to receive the effect by applying the manufacturing method of this invention.

In the method for producing inorganic filler particles of the present invention, the average particle diameter (D ₅₀ ) of the glass particles is preferably 1 μm or more. If it does in this way, it will be excellent in the fluidity | liquidity of a resin composition and will become easy to improve a moldability. Further, bubbles (interface bubbles) existing at the interface between the inorganic filler particles and the resin are easily removed.

  The method for producing a resin composition of the present invention is characterized in that the inorganic filler particles produced by the above method are mixed with a curable resin.

  The manufacturing method of the three-dimensional modeled object of the present invention includes forming a cured layer having a predetermined pattern by selectively irradiating a liquid layer made of the resin composition manufactured by the above method with active energy rays, After forming a new liquid layer on it, the active energy ray is irradiated to form a new cured layer having a predetermined pattern continuous with the cured layer, and the cured layer is laminated until a predetermined three-dimensional object is obtained. It is characterized by repetition.

  ADVANTAGE OF THE INVENTION According to this invention, the inorganic filler particle which can obtain the resin composition excellent in the whiteness reliably can be provided.

  The method for producing inorganic filler particles of the present invention is characterized in that glass particles having metal particles attached to the surface are washed with an acidic solution.

The average particle diameter (D ₅₀ ) of the glass particles is preferably 1 μm or more, 1.5 μm or more, 2 μm or more, and particularly preferably 2.5 μm or more. If the average particle size of the glass particles is too small, the resulting inorganic filler particles will also be small, and when mixed with a resin, the fluidity of the resin composition will be reduced or present at the interface between the inorganic filler particles and the resin. Bubbles (interface bubbles) are difficult to escape. On the other hand, if the average particle size of the glass particles is too large, the resulting inorganic filler particles are also large, and the filling rate of the inorganic filler particles in the resin composition tends to decrease, so that it is 500 μm or less, 100 μm or less, 50 μm or less. In particular, it is preferably 20 μm or less.

In the present invention, the average particle diameter (D ₅₀ ) indicates a 50% volume cumulative diameter in terms of the median diameter of the primary particles, and is a value measured by a laser diffraction particle size distribution analyzer.

The specific surface area of the glass particles 0.1~3.5m ² /g,0.5~3.2m ² / g, it is particularly preferably 0.75~3m ² / g. When the specific surface area of the glass particles is too small, the particle diameter of the obtained inorganic filler particles becomes large, so that the filling rate of the inorganic filler particles in the resin composition tends to decrease. On the other hand, if the specific surface area of the glass particles is too large, the specific surface area of the resulting inorganic filler particles also increases, so that the fluidity of the resin composition decreases or bubbles that exist at the interface between the inorganic filler particles and the resin. Is difficult to remove.

  The shape of the glass particles is not particularly limited, but is preferably substantially spherical. If it does in this way, since the specific surface area of an inorganic filler particle becomes small, the viscosity raise of a resin composition can be suppressed. The substantially spherical glass particles can be produced, for example, by pulverizing bulk glass and then performing flame polishing (fire polishing).

  The acid resistance of the glass particles is preferably tertiary or higher, secondary or higher, and particularly preferably primary. If the acid resistance of the glass particles is too low, the glass particle surfaces are easily eroded during cleaning.

The density of the glass particles is preferably 2.4 to 7 g / cm ³ , 2.5 to 6 g / cm ³ , and particularly preferably 2.6 to 5 g / cm ³ . If the density of the glass particles is too low, the softening point tends to be unreasonably high. On the other hand, if the density of the glass particles is too high, the inorganic filler particles are likely to settle and separate in the resin composition when the optical modeling method is applied.

As the glass particles, for example, glass containing at least one selected from SiO ₂ , Al ₂ O ₃ , B ₂ O ₃ and P ₂ O ₅ as a composition can be used. Specifically, SiO ₂ —B ₂ O ₃ —R ′ ₂ O (R ′ is an alkali metal element) glass, SiO ₂ —Al ₂ O ₃ —RO (R is an alkaline earth metal element) glass, SiO _2- Al ₂ O ₃ —R ′ ₂ O—RO glass, SiO ₂ —Al ₂ O ₃ —B ₂ O ₃ —R ′ ₂ O glass, SiO ₂ —Al ₂ O ₃ —B ₂ O ₃ —R ' ₂ O-RO-based glass, SiO ₂ -R' ₂ O-based glass, SiO ₂ -R ' ₂ O-RO-based glass, or the like can be used. Hereinafter, the preferable range of the content of each component in the glass particles will be described. In the following description, “%” means “mass%” unless otherwise specified.

From the viewpoint of obtaining inorganic filler particles having excellent acid resistance, SiO ₂ , Al ₂ O ₃ , B ₂ O ₃ and P ₂ O ₅ are contained in a total amount of 1% or more, 5% or more, and particularly 10% or more. It is preferable. However, since these are components that reduce the density, when a high-density three-dimensional model is obtained, the total amount is preferably 85% or less, 80% or less, 70% or less, and particularly preferably 60% or less.

  The glass constituting the inorganic filler particles is made of a glass having an F content of 0.5% or less, 0.25% or less, 0.1% or less, 0.05% or less, particularly 0.01% or less. . When there is too much content of F, it will become easy to elute F component and it is environmentally unpreferable.

The glass constituting the inorganic filler particles is preferably a low alkali-containing glass from the viewpoint of acid resistance. Specifically, the total amount of Li ₂ O, Na ₂ O, and K ₂ O as a glass composition is 15% or less, 10% or less, 5% or less, 2.5% or less, particularly 1% or less. It is preferable to select glass. When there is too much alkali content in glass, there exists a tendency for the acid resistance of an inorganic filler particle to fall and for the mechanical strength of a three-dimensional molded item to fall over time. In particular, when used in a humid environment, the mechanical strength tends to decrease significantly.

Specific examples of the conditions are satisfied the glass, for example, in _{mass%, SiO 2 30~85%, Al} 2 O 3 0~30%, B 2 O 3 0~50%, Li 2 O + Na 2 O + K 2 O 15% or less The glass which is is mentioned. Here, “Li ₂ O + Na ₂ O + K ₂ O” means the total content of Li ₂ O, Na ₂ O and K ₂ O. The reason for limiting the glass composition in this way will be described below.

SiO ₂ is a component that forms a glass skeleton, and is a component that improves chemical durability and resistance to devitrification. The content of SiO ₂ is preferably 30 to 85%, 40 to 75%, particularly 45 to 65%. If the amount of SiO ₂ is too small, the chemical durability tends to be lowered or the glass tends to be devitrified, and the production tends to be difficult. On the other hand, if there is too much SiO ₂ , the meltability tends to be lowered, it is difficult to soften during molding, and the production tends to be difficult.

Al ₂ O ₃ is a component that stabilizes vitrification. Moreover, there exists an effect which improves chemical durability and devitrification resistance. The content of Al ₂ O ₃ is preferably 0 to 30%, 2.5 to 25%, particularly preferably 5 to 20%. When there is too much Al ₂ O ₃ , the meltability tends to be lowered, and it becomes difficult to soften at the time of molding, and the production tends to be difficult.

B ₂ O ₃ is a component that forms a glass skeleton, and is a component that improves chemical durability and devitrification resistance. The content of B ₂ O ₃ is preferably 0 to 50%, 2.5 to 40%, particularly preferably 5 to 30%. When B ₂ O ₃ is too large, tends to decrease the melting property, also less likely to soften during molding tend to manufacture becomes difficult.

  In addition to the above, various components can be contained.

  MgO, CaO, SrO, BaO, and ZnO are components that reduce the viscosity of the glass without significantly reducing the chemical durability. These components are preferably 0 to 50%, 0.1 to 50%, 1 to 40%, particularly 2 to 30% in total. However, when there are too many these components, chemical durability will fall easily.

P ₂ O ₅ is a component that forms a glass skeleton, and is a component that improves chemical durability and devitrification resistance. The content of P ₂ O ₅ is preferably 0 to 50%, 2.5 to 40%, particularly 5 to 30%. If there is too much P ₂ O ₅ , the meltability tends to be lowered, and it becomes difficult to soften at the time of molding, and the production tends to be difficult.

In order to suppress coloring, the total content of Fe ₂ O ₃ , NiO, Cr ₂ O ₃ and CuO in the glass composition is 1% or less, 0.75% or less, particularly 0.5% or less. It is preferable. Also, the total content of TiO ₂ , WO ₃ , La ₂ O ₃ , Gd ₂ O ₃ and Bi ₂ O _{3 in} the glass composition should be 5% or less, 2.5% or less, especially 1% or less. Is preferred. If the range of these components is limited as described above, it is easy to suppress the coloring of the glass, and the increase in the refractive index and density can be suppressed, so that it becomes easy to obtain a three-dimensional structure excellent in transparency and texture.

  Since lead, mercury, chromium, cadmium, chlorine, sulfur and arsenic are environmentally hazardous substances, their contents are preferably 0.1% or less, particularly 0.01% or less, respectively, in terms of oxides. The amount is preferably 1% or less, 0.5% or less, particularly preferably 0.1% or less.

Sb ₂ O ₃ and CeO ₂ have an effect of suppressing a decrease in light transmittance caused by the Fe component. The total content of Sb ₂ O ₃ and CeO ₂ is preferably 0.01 to 1%, particularly preferably 0.1 to 0.8%. If the content of these components is too small, it is difficult to obtain the above effect. On the other hand, if the content is too large, the light transmittance tends to be lowered, or the glass tends to be devitrified during molding. Incidentally, it is preferable that the content of each of the _Sb 2 _{O 3} and CeO ₂ is within the above range.

Although it does not specifically limit as a metal particle, Generally, at least 1 sort (s) selected from Fe, Cr, and Ni which are easy to mix in the manufacturing process of a glass particle is mentioned. The average particle diameter _{(D 50)} of the metal particles, usually, 0.01 to 100 [mu] m, even at 0.1 to 10 [mu] m.

  The adhesion amount of the metal particles is, for example, 300 μg or more, 500 μg or more, further 1000 μg or more with respect to 1 g of the glass particles. When the adhesion amount of the metal particles is large, the whiteness of the inorganic filler particles is likely to be lowered, so that it is easy to enjoy the effects of applying the production method of the present invention. In addition, it is preferable that the adhesion amount of the metal particle after washing | cleaning by an acidic solution is 250 micrograms or less, 200 micrograms or less, 100 micrograms or less, especially 50 micrograms or less with respect to 1 g of glass particles.

  The pH of the acidic solution is preferably 6.5 or less, 6 or less, 5 or less, particularly 4 or less. If the pH of the acidic solution is too high, the metal particles cannot be sufficiently removed, and it becomes difficult to obtain inorganic filler particles with high whiteness. The lower limit of the pH is not particularly limited, but if it is too small, the glass particles may be eroded. Therefore, it is preferably −2 or more, particularly preferably −1 or more. Specific examples of the acid cleaning solution include hydrochloric acid, nitric acid, and sulfuric acid. These can be used individually or in mixture of 2 or more types.

  The washing time is preferably 1 hour or more, 2 hours or more, 3 hours or more, particularly 5 hours or more. If the washing time is too short, the metal particles cannot be sufficiently removed, and it becomes difficult to obtain inorganic filler particles with high whiteness. The upper limit of the washing time is not particularly limited, but if it is too long, further effects cannot be obtained, leading to a reduction in production efficiency. Therefore, it is preferably 24 hours or less, particularly 12 hours or less. In addition, a metal particle can be efficiently removed by performing a washing process, stirring an acidic solution. As a result, the cleaning time can be shortened.

  The inorganic filler particles obtained as described above are preferably surface-treated with a silane coupling agent. In this way, it is possible to increase the bonding force between the inorganic filler particles and the resin, and it is possible to obtain a three-dimensionally shaped article with more excellent mechanical strength. As the silane coupling agent, for example, aminosilane, epoxy silane, acrylic silane and the like are preferable. The silane coupling agent may be appropriately selected according to the curable resin to be used. For example, when a vinyl unsaturated compound is used as the photocurable resin, an acrylic silane silane coupling agent or an epoxy compound is used. It is preferable to use an epoxy silane-based silane coupling agent.

  A resin composition can be produced by mixing a curable resin with the inorganic filler particles. The mixing ratio is preferably volume%, and is preferably 10% to 99% curable resin and 1% to 90% inorganic filler particles. More preferably, the curable resin is 35 to 95%, 40 to 90%, particularly 45 to 85%, and the inorganic filler particles are 5 to 65%, 10 to 60%, particularly 15 to 55%. When there is too little content of an inorganic filler particle, it will become difficult to acquire the effect of the mechanical strength improvement of the three-dimensional molded item obtained. On the other hand, when the content of the inorganic filler particles is too large, the contact area with the curable resin in each inorganic filler particle becomes small, and the mechanical strength of the resulting three-dimensional structure tends to decrease. Further, in the case of the optical modeling method, the viscosity of the resin composition becomes too high, and problems such as difficulty in forming a new liquid layer on the modeling stage are likely to occur.

  As the curable resin, for example, a photocurable resin (liquid photocurable resin) can be used. As the photocurable resin, various resins such as a polymerizable vinyl compound and an epoxy compound can be selected. Monofunctional or polyfunctional compound monomers or oligomers are also used. These monofunctional compounds and polyfunctional compounds are not particularly limited. For example, typical examples of the photocurable resin are listed below.

  Monofunctional compounds of polymerizable vinyl compounds include isobornyl acrylate, isobornyl methacrylate, ginklopentenyl acrylate, bornyl acrylate, bornyl methacrylate, 2-hydroxyethyl acrylate, 2-hydroxypropyl acrylate, propylene glycol Examples include acrylate, vinyl pyrrolidone, acrylamide, vinyl acetate, and styrene. Examples of the polyfunctional compound include trimethylolpropane triacrylate, EO-modified trimethylolpropane triacrylate, ethylene glycol diacrylate, tetraethylene glycol diacrylate, polyethylene glycol diacrylate, 1,4-butanediol diacrylate, 1,6 -Hexanediol diacrylate, neopentyl glycol diacrylate, dicyclopentenyl diacrylate, polyester diacrylate, diallyl phthalate and the like. One or more of these monofunctional compounds and polyfunctional compounds can be used alone or in the form of a mixture.

  As a polymerization initiator for the vinyl compound, a photopolymerization initiator is used. As photopolymerization initiators, 2,2-dimethoxy-2-phenylacetophenone, 1-hydroxycyclohexyl phenyl ketone, acetophenone, benzophenone, xanthone, fluorenone, benzaldehyde, fluorene, anthraquinone, triphenylamine, carbazole, 3-methylacetophenone, Michler's ketone and the like can be mentioned as typical ones, and these initiators can be used alone or in combination of two or more. If necessary, a sensitizer such as an amine compound can be used in combination. It is preferable that the usage-amount of these polymerization initiators is 0.1-10 mass% with respect to a vinyl type compound, respectively.

  Examples of the epoxy compound include hydrogenated bisphenol A diglycidyl ether, 3,4-epoxycyclohexylmethyl-3,4-epoxycyclohexanecarboxylate, 2- (3,4-epoxycyclohexyl-5,5-spiro-3,4. -Epoxy) cyclohexane-m-dioxane, bis (3,4-epoxycyclohexylmethyl) adipate and the like. When using these epoxy compounds, an energy active cationic initiator such as triphenylsulfonium hexafluoroantimonate can be used.

  Furthermore, a leveling agent, a surfactant, an organic polymer compound, an organic plasticizer, and the like may be added to the photocurable resin as necessary.

  Next, an example of the manufacturing method of a three-dimensional molded item is demonstrated. Specifically, the manufacturing method of the three-dimensional molded item using the resin composition containing photocurable resin is demonstrated. The resin composition is as described above, and the description is omitted here.

  First, one liquid layer made of a photocurable resin composition is prepared. For example, a modeling stage is provided in a tank filled with a liquid photocurable resin composition, and the stage upper surface is positioned so as to have a desired depth (for example, about 0.2 mm) from the liquid surface. By doing in this way, a liquid layer can be prepared on a stage.

  Next, the liquid layer is irradiated with an active energy ray, for example, an ultraviolet laser to cure the photocurable resin, thereby forming a cured layer having a predetermined pattern. As the active energy ray, laser light such as visible light and infrared light can be used in addition to ultraviolet light.

  Then, the new liquid layer which consists of a photocurable resin composition is prepared on the formed cured layer. For example, by lowering the modeling stage by one layer, a photocurable resin can be introduced onto the cured layer to prepare a new liquid layer.

  Thereafter, an active energy ray is irradiated to a new liquid layer prepared on the cured layer to form a new cured layer continuous with the cured layer.

  By repeating the above operation, the hardened layer is continuously laminated to obtain a predetermined three-dimensional object.

The inorganic filler particles produced by the method of the present invention are excellent in whiteness, and can achieve a whiteness L ^* of, for example, 86 or more, 88 or more, particularly 90 or more. Further, the resin composition obtained by blending the inorganic filler particles produced by the method of the present invention with a resin is also excellent in whiteness, for example, when 30% by volume of inorganic filler particles is blended in the resin composition , Whiteness L ^* of 45 or more, 50 or more, particularly 55 or more can be achieved.

  EXAMPLES The present invention will be described below based on examples, but the present invention is not limited to the following examples.

  Table 1 shows Examples 1 and 2 of the present invention and a comparative example.

(Preparation of inorganic filler particles)
By mass%, SiO ₂ 52%, B ₂ O ₃ 7%, Al ₂ O ₃ 14%, MgO 0.5%, CaO 25%, Na ₂ O 0.6%, K ₂ O 0.1%, TiO ₂ Raw materials were prepared so as to have a glass composition of 0.5% and F 0.3%, melted at 1500 to 1600 ° C. for 4 to 8 hours, and then formed into a film. By pulverizing the film-like glass, glass particles (softening point 800 ° C.) having an average particle diameter of 5 μm were obtained. When the surface deposits of the obtained glass particles were analyzed, 1605 μg of metal particles (Fe 1500 μg, Cr 100 μg, Ni 5 μg) were adhered to 1 g of the glass particles.

The obtained glass particles were washed with an acidic solution described in Table 1 (30 ° C.) for 4 hours to obtain inorganic filler particles. In addition, about the comparative example, the washing | cleaning by an acidic solution was not performed. About the obtained inorganic filler particle | grains, the whiteness L ^* value was measured using the color difference meter. The results are shown in Table 1. When the surface adhering matter of the inorganic filler particles obtained in Example 1 was analyzed, 200 μg of metal particles (Fe 170 μg, Cr 25 μg, Ni 5 μg) were attached to 1 g of the glass particles.

(Production of photocurable resin)
First, isophorone diisocyanate, morpholine acrylamide and dibutyltin dilaurate were heated in an oil bath. A solution in which methylhydroquinone was uniformly mixed and dissolved in glycerin monomethacrylate monoacrylate was added, and the mixture was stirred and reacted. A propylene oxide 4 mol adduct of pentaerythritol (1 mol of propylene oxide added to 4 hydroxyl groups of pentaerythritol) was added and reacted to produce a reaction product containing a urethane acrylate oligomer and morpholine acrylamide.

  Morpholine acrylamide and dicyclopentanyl diacrylate were added to the obtained urethane acrylate oligomer and morpholine acrylamide. Further, 1-hydroxycyclohexyl phenyl ketone (photopolymerization initiator) was added to obtain a colorless and transparent acrylic photocurable resin.

(Preparation of resin composition for three-dimensional modeling and production of three-dimensional modeling)
A paste-like resin composition in which 30% by volume of inorganic filler particles are added to 70% by volume of the photocurable resin obtained above, and kneaded with three rollers to uniformly disperse the inorganic filler particles. Obtained. The obtained resin composition was poured into a mold made of Teflon and having an inner size of 30 mm □. Then, after irradiating the light of 500mW and wavelength 364nm and hardening a resin composition, the three-dimensional molded item was obtained by annealing at 80 degreeC. About the obtained three-dimensional molded item, the whiteness L ^* value was measured using the color difference meter. The results are shown in Table 1.

As is clear from Table 1, the inorganic filler particles of Examples 1 and 2 prepared by washing glass particles with an acidic solution have a high whiteness L ^* value of 90 or more, and the inorganic filler The three-dimensional structure produced from the resin composition using particles also had a high whiteness L ^* value of 63 or more. On the other hand, the inorganic filler particles of the comparative example obtained without washing the glass particles with an acidic solution have a low whiteness L ^* value of 85 and are prepared from a resin composition using the inorganic filler particles. The three-dimensional modeled product also had a low whiteness L ^* value of 40.

Claims (8)

  A method for producing inorganic filler particles, wherein glass particles having metal particles attached to the surface are washed with an acidic solution.   The method for producing inorganic filler particles according to claim 1, wherein the acidic solution has a pH of 6.5 or less.   The method for producing inorganic filler particles according to claim 1 or 2, wherein the acidic solution is at least one selected from hydrochloric acid, sulfuric acid, and nitric acid.   The method for producing inorganic filler particles according to any one of claims 1 to 3, wherein the metal particles comprise at least one selected from Fe, Cr and Ni.   The method for producing inorganic filler particles according to any one of claims 1 to 4, wherein the adhesion amount of metal particles is 300 µg or more per 1 g of glass particles. Method of producing an inorganic filler particles according to any one of claims 1-5, an average particle diameter of the glass particles (D ₅₀₎ is characterized in that at 1μm or more.   A method for producing a resin composition, comprising mixing inorganic filler particles produced by the method according to any one of claims 1 to 6 and a curable resin.   A liquid layer made of the resin composition produced by the method according to claim 7 is selectively irradiated with active energy rays to form a cured layer having a predetermined pattern, and a new liquid layer is formed on the cured layer. After the formation, the active energy ray is irradiated to form a new hardened layer having a predetermined pattern continuous with the hardened layer, and the solidification of the hardened layer is repeated until a predetermined three-dimensional object is obtained. Manufacturing method of a model.