JP7356634B2 - Resin composition, three-dimensional molded object, and method for producing three-dimensional molded object - Google Patents

Description

The present invention relates to a resin composition, a three-dimensional structure, and a method for producing a three-dimensional structure.

2. Description of the Related Art Conventionally, methods for obtaining three-dimensional objects by laminating resin materials and the like have been known. For example, various methods such as stereolithography, powder bed fusion bonding (PBF), and fused deposition modeling (FDM) have been proposed and put into practical use.

For example, stereolithography is widely used because it excels in finely detailed modeling and accurate size expression. In this method, a three-dimensional object is produced as follows. First, a modeling stage is provided in a tank filled with liquid photocurable resin, and the photocurable resin on the modeling stage is irradiated with an ultraviolet laser to produce a cured layer in a desired pattern. After one layer of cured layer is formed in this way, the modeling stage is lowered by one layer and uncured resin is introduced onto the cured layer. Thereafter, a new cured layer is stacked on the cured layer by irradiating the photocurable resin with an ultraviolet laser in the same manner. By repeating this operation, a predetermined three-dimensional object is obtained (for example, see Patent Document 1).

Further, in the powder bed fusion bonding method (PBF), a three-dimensional object is produced by laminating powder raw materials layer by layer and melting and solidifying the powder particles using a laser or the like. Specifically, a modeling stage is set up in a tank filled with powder of resin, metal, ceramics, glass, etc., and the powder on the modeling stage is irradiated with semiconductor laser or electron beam to soften and solidify the desired material. Create a cured layer with a pattern of After that, a new hardened layer is piled up on the hardened layer and this operation is repeated to obtain a predetermined three-dimensional structure.

Further, in the fused modeling method (FDM), layers are formed by extruding a molten material through a nozzle, and the layers are piled up to produce a three-dimensional object. For example, a filament made of a material containing thermoplastic resin molded into a linear shape is used as the material, melted with heat to a semi-liquid state, and a single layer is produced while controlling the position of the nozzle using a computer. After that, a new hardened layer is piled up on the hardened layer and this operation is repeated to obtain a predetermined three-dimensional structure.

Japanese Patent Application Publication No. 7-26060

In recent years, with the development of three-dimensional modeling methods, it has become possible to obtain three-dimensional objects with more complex and precise shapes. In addition to prototype models, three-dimensional objects created with 3D printers are now being used for parts of actual electrical products. In particular, when used for internal parts of electrical products, it is important to efficiently radiate heat generated inside the electrical product to the outside.

The object of the present invention is to relate to a resin composition, a three-dimensional structure, and a method for producing a three-dimensional structure with which a three-dimensional structure with good thermal conductivity can be obtained.

That is, the resin composition of the present invention is a resin composition containing a resin and inorganic filler particles, wherein the surface of the inorganic filler particles is made of one or more types selected from metals, oxides, and nitrides. It is characterized in that it is coated with a coating, and the thermal conductivity of the coating is 2 W/m·K or more. In this way, it becomes easier to obtain a three-dimensional structure with good thermal conductivity.

Further, in the resin composition of the present invention, it is preferable that the coating is a thin film. In this way, it is easy to form a coating having a uniform thickness on the inorganic filler particles.

Further, in the resin composition of the present invention, it is preferable that the coating is fine particles. Since this can be done by mixing inorganic filler particles and fine particles, various materials can be used as the coating. Furthermore, manufacturing costs can be reduced.

Moreover, in the resin composition of the present invention, it is preferable that the average particle diameter of the fine particles is 1 μm or less. Note that the average particle diameter refers to the particle diameter (D ₅₀ ) measured by laser diffraction.

Further, in the resin composition of the present invention, it is preferable that the aspect ratio (length/diameter) of the inorganic filler particles is 1.1 or more. In this way, the inorganic filler particles in the three-dimensional structure come into contact with each other to easily form a heat conduction path, and as a result, the thermal conductivity of the three-dimensional structure tends to improve. Note that the "aspect ratio" is a value mainly used when the particles are columnar or fibrous, and is the ratio of the "length" to the "diameter" of the particles. Here, "diameter" means a value obtained by dividing the sum of the maximum diameter and minimum diameter of a particle cross section (a cross section perpendicular to the length direction) by 2. Moreover, the measurement of "diameter" and "length" can be obtained by observing and photographing with a digital scope and calculating the average of 100 randomly selected particles in the field of view.

Further, in the resin composition of the present invention, it is preferable that the inorganic filler particles are glass. Since glass can be easily formed into various compositions and shapes, it is easy to impart desired properties to three-dimensional objects.

Further, in the resin composition of the present invention, it is preferable that the inorganic filler particles contain SiO ₂ +Al ₂ O ₃ +B ₂ O ₃ +P ₂ O ₅ in an amount of 50% by mass or more based on the glass composition.

Further, in the resin composition of the present invention, the inorganic filler particles, as a glass composition, contain, in mass %, SiO ₂ 10 to 85%, Al ₂ O ₃ 0 to 30%, B ₂ O ₃ 0 to 50%, It is preferable to contain 0 to 50% of P ₂ O ₅ and 0 to 12% of R ₂ O (R is at least one selected from Li, Na, and K).

Further, in the resin composition of the present invention, it is preferable that the heat resistant temperature of the coating is 200° C. or higher. In this way, it is easy to improve the heat resistance of the three-dimensional structure.

Further, in the resin composition of the present invention, it is preferable that the density of the coating is 1.9 to 12.0 g/cm ³ . In this way, it becomes easier to obtain a three-dimensional structure with good thermal conductivity.

The resin composition of the present invention preferably has a thermal conductivity of 0.6 W/m·K or more. In this way, it becomes easier to obtain a three-dimensional structure with good thermal conductivity.

A resin composition according to another aspect of the present invention is a resin composition containing a resin and inorganic filler particles, wherein the surface of the inorganic filler particles is one or more selected from metals, oxides, and nitrides. The electrical conductivity of the coating is 0.01Ω ⁻¹ cm ⁻¹ or more. In this way, it becomes easier to obtain a three-dimensional structure with good electrical conductivity.

The resin composition of the present invention preferably has an electrical conductivity of 0.001Ω ⁻¹ cm ⁻¹ or more. In this way, it becomes easier to obtain a three-dimensional structure with good electrical conductivity.

The three-dimensional structure of the present invention is characterized by comprising the above-described resin composition for three-dimensional structures.

Furthermore, in the method for producing a three-dimensional object of the present invention, a precursor layer made of a resin composition is formed and cured to form a cured layer having a predetermined pattern, and a new precursor layer is formed on the cured layer. A method of manufacturing a three-dimensional object by forming and curing a new hardened layer having a predetermined pattern that is continuous with the previous hardened layer, and repeating the lamination of the cured layers until a predetermined three-dimensional object is obtained. The present invention is characterized in that the resin composition described above is used as the resin composition.

According to the present invention, it becomes easy to obtain a resin composition capable of obtaining a three-dimensional structure with good thermal conductivity and a three-dimensional structure with good thermal conductivity.

The resin composition of the present invention contains at least a resin and inorganic filler particles. The content of the resin in the resin composition for three-dimensional objects is preferably 30 to 99% by volume, 35 to 95%, 40 to 90%, 45 to 85%, particularly preferably 50 to 80%. It is. If the content of the resin is too large, the content of the inorganic filler particles will be relatively small, and the properties such as thermal conductivity and mechanical strength of the three-dimensional structure will tend to deteriorate. On the other hand, if the resin content is too low, the fluidity of the resin composition during softening and melting may decrease, and the mechanical strength of the three-dimensional object may actually decrease due to insufficient adhesion between the resin and the inorganic filler particles. There is a possibility that

The resin may be a curable resin such as a photocurable resin or a thermosetting resin, or a thermoplastic resin.

For example, the photocurable resin includes a liquid photocurable resin. Specifically, various resins such as polymerizable vinyl compounds and epoxy compounds can be selected. Furthermore, monomers and oligomers of monofunctional compounds and polyfunctional compounds are used. These monofunctional compounds and polyfunctional compounds are not particularly limited. For example, typical photocurable resins are listed below.

Examples of monofunctional polymerizable vinyl compounds include isobornyl acrylate, isobornyl methacrylate, zinclopentenyl acrylate, bornyl acrylate, bornyl methacrylate, 2-hydroxyethyl acrylate, 2-hydroxypropyl acrylate, and propylene glycol. Examples include acrylate, vinylpyrrolidone, acrylamide, vinyl acetate, and styrene. Further, as polyfunctional compounds, 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.

A photopolymerization initiator is used as the polymerization initiator for the vinyl compound. Examples of the photopolymerization initiator include 2,2-dimethoxy-2-phenylacetophenone, 1-hydroxycyclohexylphenylketone, acetophenone, benzophenone, xanthone, fluorenone, benzaldehyde, fluorene, anthraquinone, triphenylamine, carbazole, 3-methylacetophenone, Michler's ketone and the like can be cited as a typical initiator, and these initiators can be used alone or in combination of two or more. It is also possible to use a sensitizer such as an amine compound in combination, if necessary. The amount of each of these polymerization initiators used is preferably 0.1 to 10% by mass based on the vinyl compound.

Examples of epoxy compounds 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, energy-active cationic initiators such as triphenylsulfonium hexafluoroantimonate can be used.

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

In addition, typical thermoplastic resins are listed below.

Examples of thermoplastic resins include polyolefin resins, polyester resins, polyacrylic acid ester resins, polyoxymethylene resins, polyethylene resins, polypropylene resins, polystyrene resins, acrylonitrile-styrene resins, acrylonitrile-butadiene-styrene resins, and polyvinyl chloride resins. , polyvinyl acetate resin, polyvinyl alcohol resin, polyvinyl acetal resin, methacrylic resin, polyethylene terephthalate resin, etc. Further, there are polyamide resins, polyacetal resins, polycarbonate resins, modified polyphenylene ether resins, polyethylene terephthalate resins, polybutylene terephthalate resins, ultra-high molecular weight polyethylene resins, and the like. Furthermore, polyphenylene sulfide resin, polysulfone resin, polyimide resin, polyetherimide resin, polyesterimide resin, polyamideimide resin, polyarylate resin, polyethersulfone resin, polyetheretherketone resin, liquid crystal polymer resin, fluororesin, etc. be.

Thermoplastic resins can be classified into general-purpose resins, engineering plastics, and super engineering plastics depending on their heat resistance, and these may be appropriately selected according to the purpose of the three-dimensional object. For example, when heat resistance at a continuous use temperature of 100°C or higher is required, it is preferable to use an engineering plastic, and when heat resistance at a continuous use temperature of 150°C or higher is required, it is preferable to use a super engineering plastic.

Typical engineering plastics include polyamide resins, polyacetal resins, polycarbonate resins, modified polyphenylene ether resins, polyethylene terephthalate resins, polybutylene terephthalate resins, ultra-high molecular weight polyethylene resins, and the like. Typical super engineering plastics include polyphenylene sulfide resin, polysulfone resin, polyimide resin, polyetherimide resin, polyesterimide resin, polyamideimide resin, polyarylate resin, polyethersulfone resin, polyetheretherketone resin, Examples include liquid crystal polymer resins and fluororesins.

The resin composition of the present invention may also contain various additive components, such as leveling agents, surfactants, antioxidants, nucleating agents, plasticizers, mold release agents, etc., as long as the object of the present invention is not impaired. Appropriate amounts of additives such as flame retardants, pigments, carbon black, and antistatic agents may be included.

Next, the inorganic filler particles will be explained.

The content of inorganic filler particles in the resin composition is preferably 1 to 70% by volume, 5 to 65%, 10 to 60%, 15 to 55%, particularly preferably 20 to 50%. be. If the content of the inorganic filler particles is too small, the properties such as thermal conductivity and mechanical strength of the three-dimensional structure will tend to deteriorate. On the other hand, if the content of inorganic filler particles is too large, the fluidity of the resin composition during softening and melting may decrease, or the mechanical strength of the three-dimensional object may deteriorate due to insufficient adhesion between the resin and the inorganic filler particles. There is a risk that it may decline.

The inorganic filler particles according to the present invention are characterized in that their surfaces are coated with a coating made of one or more types selected from metals, oxides, and nitrides. In this way, it becomes easier to obtain a three-dimensional structure with good thermal conductivity.

Examples of metals include silver, copper, aluminum, gold, magnesium, and calcium. In addition, coating methods include PVD methods such as vacuum evaporation method and sputtering method, CVD methods such as thermal CVD method, optical CVD method, plasma-induced CVD method, and atomic layer growth method, as well as dry plating method and wet plating method. When employing this, it is preferable to select metal as the coating.

Examples of oxides include magnesium oxide, tin oxide, bismuth oxide, and lead oxide. Further, examples of the nitride include boron nitride, aluminum nitride, gallium nitride, and silicon nitride. In addition, when adopting fine particle attachment as a coating method, it is preferable to select an oxide or a nitride as the coating material. In that case, in order to coat uniformly, the particle size is preferably 0.001 to 0.3 μm, 0.002 to 0.2 μm, 0.003 to 0.1 μm, and 0.003 to 0.0.07 μm. , 0.005 to 0.1 μm, particularly preferably 0.005 to 0.03 μm.

Furthermore, the thermal conductivity of the coating of inorganic filler particles according to the present invention is 2 W/m·K or more, preferably 10 W/m·K or more, 100 W/m·K or more, or 200 W/m·K or more. , 300 W/m·K or more. When coated with a coating having high thermal conductivity, the thermal conductivity of the inorganic filler particles can be improved, which in turn makes it easier to obtain a three-dimensional structure with good thermal conductivity. Examples of coating materials for inorganic filler particles having high thermal conductivity include silver, copper, gold, aluminum, and carbon.

The coating of the inorganic filler particles according to the present invention is preferably a thin film. In this case, the method of forming a film on the surface of the inorganic filler particles does not matter; it may be a PVD method such as a vacuum evaporation method or a sputtering method, or a CVD method such as a thermal CVD method, a photo CVD method, a plasma-induced CVD method, or an atomic layer deposition method. Alternatively, any method such as dry plating or wet plating may be used. When the coating is a thin film, it is easy to form a coating with a uniform thickness on the inorganic filler particles.

Further, it is preferable that the surface of the inorganic filler particles according to the present invention is coated with fine particles. The fine particles can be attached, for example, by mixing the inorganic filler particles and the fine particles. For example, by heating during mixing, fine particles can be firmly bound to the surfaces of the inorganic filler particles. For example, when the inorganic filler particles are glass, the heating temperature is preferably within ±100°C, within ±50°C, or within ±30°C of the softening point.

Further, in the inorganic filler particles according to the present invention, the average particle diameter (D ₅₀ ) of the fine particles adhering to the surface is preferably 1 μm or less, 0.001 to 0.5 μm, 0.003 to 0.3 μm, particularly 0. .01 to 0.1 μm or less. If the fine particles are too large, it will be difficult to uniformly coat the surface of the inorganic filler particles, and the thermal conductivity will tend to decrease. On the other hand, if the fine particles are too small, the material cost tends to increase.

Furthermore, the inorganic filler particle coating according to the present invention has a heat resistance temperature of preferably 200°C or higher, 250°C or higher, 300°C or higher, particularly preferably 400°C or higher. If the heat resistance temperature is too low, there is a possibility that the heat resistance of the obtained three-dimensional structure will be reduced.

Further, the coating according to the present invention preferably has a density of 1.9 to 12.0 g/cm ³ 1.9 to 10.0 g/cm ³ , 1.9 to 9.0 g/cm ³ It is preferably 6.0 g/cm ³ , 2.0 to 4.5 g/cm ³ , particularly 2.3 to 4.0 g/cm ³ . The closer the density of the coating material to the density of the inorganic filler particles, the easier it is to coat the particles uniformly. Further, there is a tendency that the higher the density, the more materials have good thermal conductivity, which is preferable.

Further, the coating according to the present invention preferably has an adhesion amount of 0.01 wt% or more, 0.1 wt% or more, 0.5 wt% or more, 1 wt% or more, 5 wt% or more, 10 wt% or more, 15 wt% The above content is preferably 20 wt% or more, 30 wt% or more, 40 wt% or more, 45 wt% or more, or 60 wt% or more. The larger the amount of the coating applied, the easier it is to obtain a three-dimensional structure with good thermal conductivity.

Further, regarding the size of the inorganic filler particles according to the present invention, the average particle diameter D ₅₀ is preferably 0.1 to 300 μm, 1 to 200 μm, more than 1 to 200 μm, 1.5 to 150 μm, and 2 to 100 μm. , 3 to 50 μm, particularly 4 to 40 μm. Further, the maximum particle size of the inorganic filler particles is preferably 500 μm or less, particularly 300 μm or less, and the minimum particle size is preferably 0.05 μm or more, particularly 0.5 μm or more. As the particle size of the inorganic filler particles becomes smaller, the filling rate of the inorganic filler particles in the three-dimensional object can be increased, so the properties such as thermal conductivity of the three-dimensional object can be improved. There is a risk of a decrease in fluidity and an increase in interfacial bubbles. On the other hand, the larger the particle size of the inorganic filler particles, the lower the filling rate and the more difficult it becomes to obtain desired characteristics.

The inorganic filler particles according to the present invention may have any shape, such as columnar, fibrous, true spherical, approximately spherical, go stone, or crushed shape. Furthermore, the surface roughness of the obtained inorganic filler particles may be reduced using a method such as fire polishing. In this way, the fluidity of the resin composition can be improved and unreasonable increases in viscosity can be suppressed. In particular, the inorganic filler particles of the present invention preferably have a columnar shape. When the shape is columnar, the inorganic filler particles in the three-dimensional structure tend to come into contact with each other, so a heat conduction path is easily formed, and as a result, the thermal conductivity of the three-dimensional structure tends to improve.

When the inorganic filler particles are columnar, the diameter of the inorganic filler particles is preferably 1 to 20 μm, 2.5 to 17.5 μm, 5 to 15 μm, 6 to 12.5 μm, particularly preferably 7 to 10 μm. If the diameter of the inorganic filler particles is too small, they will break during kneading with the resin, making it difficult to improve the thermal conductivity and mechanical strength of the three-dimensional structure. Further, there is a possibility that interfacial bubbles (bubbles existing at the interface between the resin and the inorganic filler particles) of the resin composition will be difficult to escape. On the other hand, if the diameter of the inorganic filler particles is too large, the resin composition tends to become non-uniform, or it becomes difficult to increase the content of the inorganic filler particles in the resin composition. As a result, it becomes difficult to improve thermal conductivity and mechanical strength.

Further, the aspect ratio (length/diameter) of the inorganic filler particles is preferably 1.1 or more, 1.2 to 100, 1.3 to 80, 1.5 to 50, 2.0 to 20, Particularly preferably 2.5 to 10. If the aspect ratio of the inorganic filler particles is too small, it becomes difficult for the inorganic filler particles in the three-dimensional structure to come into contact with each other, making it difficult to improve the thermal conductivity of the three-dimensional structure. Moreover, it becomes difficult to improve the mechanical strength of the three-dimensional structure. On the other hand, if the aspect ratio of the inorganic filler particles is too large, the granular particles tend to become entangled with each other, which may reduce the homogeneity and fluidity of the resin composition.

The Young's modulus of the inorganic filler particles is preferably 50 GPa or more, 55 GPa or more, particularly preferably 60 GPa or more. If the Young's modulus is too low, it will be difficult to improve the mechanical strength of the three-dimensional structure. Note that Young's modulus can be measured by a resonance method.

Further, the density of the inorganic filler particles is 2.2 to 7 g/cm ³ , 2.35 to 6.5 g/cm ³ , 2.5 to 6 g/cm ³ , particularly 2.6 to 5 g/cm ³ It is preferable. If the density of the inorganic filler particles is too low, it will be easy to give a solid feeling and aesthetics to the three-dimensional structure. On the other hand, if the density of the inorganic filler particles is too high, sedimentation and separation will occur easily during production of the resin composition.

Moreover, the surface of the inorganic filler particles after being coated with a coating material may be treated with a silane coupling agent. If treated with a silane coupling agent, the bonding strength between the inorganic filler particles and the thermoplastic resin will be increased, and the compatibility will be improved, making it easier to obtain three-dimensional objects with better mechanical strength. Preferred examples of the silane coupling agent include aminosilane, epoxysilane, and acrylicsilane. Note that the silane coupling agent may be appropriately selected depending on the resin used.

In addition, the specific surface area of the inorganic filler particles is 0.1 to 5 m ² /g, 0.1 to 3.5 ^{m 2} /g, 0.5 to 3.2 ^{m 2} /g, especially 0.75 to 3 m ^{2 /} g. It is preferable that it is g. If the specific surface area of the inorganic filler particles is too small, the particle size of the inorganic filler particles becomes large, and 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 inorganic filler particles is too large, the fluidity of the resin composition will decrease or bubbles present at the interface between the inorganic filler particles and the resin will become difficult to escape.

Next, the material of the inorganic filler particles will be explained.

The inorganic filler particles according to the present invention may be made of any material such as ceramics, glass, crystals, or crystallized glass, but glass is particularly preferable. Since glass can be easily formed into various compositions and shapes, for example, by adjusting the glass composition, it is easy to impart desired properties to three-dimensional objects, such as improving chemical durability and strength.

For example, as an example of a glass composition, one containing at least one selected from SiO ₂ , Al ₂ O ₃ , B ₂ O ₃ and P ₂ O ₅ can be used. For example, 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 glass, SiO ₂ -R' ₂ O glass, SiO ₂ -R' ₂ O-RO glass, etc. can be used. Moreover, E glass, A glass, EC glass, etc. can also be used.

A specific glass composition will be explained below. However, in view of the spirit of the present invention, it is clear that the composition is not limited to these compositions. In the following description, "%" indicates mass % unless otherwise specified.

The glass composition preferably contains SiO ₂ +Al ₂ O ₃ +B ₂ O ₃ +P ₂ O ₅ in an amount of 50% or more, 52.5% or more, particularly 55% or more in mass %. If the content of SiO ₂ +Al ₂ O ₃ +B ₂ O ₃ +P ₂ O ₅ is too small, the Young's modulus of the glass will decrease, and the effect of improving the mechanical strength of the three-dimensional object will decrease. In addition, examples of glass compositions having the above characteristics include, in mass %, SiO ₂ 10-85%, Al ₂ O ₃ 0-30%, B ₂ O ₃ 0-50%, P ₂ O ₅ 0-50%, Examples include glasses containing 0 to 12% of R ₂ O (R is at least one selected from Li, Na, and K).

SiO ₂ is a component that forms a glass skeleton, tends to improve chemical durability, and has the effect of suppressing devitrification. The content of SiO ₂ is preferably 10-85%, 20-80%, 30-75%, 40-70%, particularly preferably 45-70%. Too little SiO ₂ makes it difficult to obtain the above effects. On the other hand, if there is too much SiO ₂ , the softening point tends to be high and the moldability tends to be poor.

Al ₂ O ₃ is a vitrification stabilizing component. It is also highly effective in improving chemical durability. The content of Al ₂ O ₃ is preferably between 0 and 30%, particularly preferably between 2.5 and 25%, particularly preferably between 5 and 20%. Too much Al ₂ O ₃ increases the softening point and makes it difficult to mold. Furthermore, the meltability and chemical durability tend to decrease, and devitrification tends to occur.

B ₂ O ₃ is a component that forms a glass skeleton. Moreover, it is easy to improve chemical durability and has the effect of suppressing devitrification. The content of B ₂ O ₃ is preferably between 0 and 50%, particularly preferably between 2.5 and 40%, particularly preferably between 5 and 30%. If the content of B ₂ O ₃ is too large, the melting properties will be reduced or it will be difficult to soften during molding, making it difficult to manufacture.

P ₂ O ₅ is a component that forms a glass skeleton, easily improves light transmittance and chemical durability, and also has the effect of suppressing devitrification. 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 , meltability tends to decrease. Moreover, weather resistance tends to decrease. On the other hand, if P ₂ O ₅ is too small, devitrification tends to occur.

Li ₂ O, Na ₂ O and K ₂ O are components that lower the softening point and facilitate molding. The content of R ₂ O (R is at least one selected from Li, Na, and K) is preferably 0 to 12%, more than 0 to 10%, 0.01 to 9%, 0.1 ~8%, particularly preferably 1-7%. If there is too much R ₂ O, the coefficient of thermal expansion will increase and the chemical durability will tend to decrease. The content of Li ₂ O + Na ₂ O + K ₂ O (total content of Li ₂ O, Na ₂ O, and K ₂ O) is also preferably 0 to 12%, more than 0 to 10%, 0. 0.01 to 9%, 0.1 to 8%, particularly preferably 1 to 7%.

Moreover, the following components can be contained as needed.

MgO, CaO, SrO, BaO, and ZnO are components that reduce viscosity without significantly reducing chemical durability. It is also a component that suppresses devitrification. The content of CaO+MgO+BaO+SrO is preferably 0-10%, 0.1-8%, 1-6%, particularly preferably 2-5%. If the content of these components is too large, devitrification tends to occur. Note that "CaO+MgO+BaO+SrO" is the total content of CaO, MgO, BaO, and SrO. Further, the content of each component of CaO, MgO, BaO and SrO is preferably 0 to 10%, 0.1 to 8%, 1 to 6%, particularly preferably 2 to 5%.

TiO ₂ , WO ₃ and Nb ₂ O ₅ are components that easily improve the chemical durability of glass and do not significantly increase the viscosity. In addition, it is a component that can easily adjust the refractive index of glass. The content of TiO ₂ +WO ₃ +Nb ₂ O ₅ is 0 to 15%, preferably 0 to 15%, 0.1 to 12.5%, 1 to 10%, particularly preferably 2 to 7.5%. %. If the content of these components is too large, it may become colored or easily devitrified. _In addition, " _TiO2 + _WO3 + _Nb2O5 " is the total content of _TiO2 , _{WO3 ,} and _Nb2O5 .

Further, the content of each component of TiO ₂ , WO ₃ and Nb ₂ O ₅ is preferably 0 to 15%, 0.1 to 10%, 1 to 5%, particularly preferably 2 to 3%. . If the content of these components is too large, it may become colored or easily devitrified.

ZnO is a component that reduces viscosity without significantly reducing chemical durability. The total content of ZnO is preferably 0 to 50%, 0.1 to 50%, 1 to 40%, particularly preferably 2 to 30%. If the content of these components is too large, devitrification tends to occur.

Further, in any glass composition, for environmental reasons, it is preferable that the content of lead, mercury, chromium, cadmium, fluorine, and arsenic in the glass composition is each 0.01% by mass or less.

In the inorganic filler particles according to the present invention, two or more shapes and materials may be used in combination in any proportion depending on desired characteristics.

Further, the resin composition of the present invention preferably has a thermal conductivity of 0.6 W/m·K or more, 0.8 W/m·K or more, 1.0 W/m·K or more, 1.5 W/m·K or more. m·K or more, and 2W/m·K or more. Since the resin composition of the present invention contains inorganic filler particles covered with a coating having high thermal conductivity, the thermal conductivity of the resin composition can be increased, resulting in three-dimensional modeling with good thermal conductivity. It becomes easier to get things.

Furthermore, nanofillers may be added to the resin composition of the present invention in addition to the above-mentioned inorganic filler particles. By doing so, the mechanical strength of the three-dimensional structure can be improved. The content of nanofiller is preferably 0 to 3%, less than 0.01 to 2%, 0.1 to 1%, and 0.2 to 1% by volume. If the nanofiller content is too high, the material cost will increase. Furthermore, the fluidity of the resin composition during three-dimensional modeling may be reduced, and interfacial bubbles may be difficult to remove.

Note that nanofillers are particles that are about the wavelength of visible light or smaller than that, so they generally do not cause light scattering and have the characteristic that they do not easily affect the transparency and whiteness of three-dimensional structures. As the nanofiller, ZrO ₂ , Al ₂ O ₃ , SiO ₂ and the like can be used.

The average particle diameter D ₅₀ of the nanofiller is preferably 0.001 to 0.3 μm, 0.002 to 0.2 μm, 0.003 to 0.1 μm, 0.003 to 0.0.07 μm, 0. 0.005 to 0.1 μm, particularly preferably 0.005 to 0.03 μm. If the average particle size _D50 of the nanofiller is too small, the material cost will increase or it will be difficult for interfacial bubbles to come out.
On the other hand, if the average particle _D50 of the nanofiller is too large, the fluidity of the resin composition during three-dimensional modeling tends to decrease.

Furthermore, a resin composition according to another aspect of the present invention is a resin composition containing a resin and inorganic filler particles, wherein the surface of the inorganic filler particles is one selected from metals, oxides, and nitrides. It is characterized in that it is coated with a coating consisting of at least one type of coating, and the electrical conductivity of the coating is 0.01Ω ^-1 cm ^-1 or more.

The electrical conductivity of the coating of inorganic filler particles according to the present invention is preferably 0.01 Ω ^-1 cm ^-1 , 1 Ω ^-1 cm ^-1 or more, 10 Ω ^-1 cm ^-1 or more, 20 Ω ^-1 cm ^-1 30Ω ⁻¹ cm ⁻¹ or more, 50Ω ⁻¹ cm ⁻¹ or more, and 60Ω ⁻¹ cm ⁻¹ or more. When coated with a coating having high electrical conductivity, the electrical conductivity of the inorganic filler particles can be improved, which in turn makes it easier to obtain a three-dimensional structure with good electrical conductivity. Examples of coating materials for inorganic filler particles having high electrical conductivity include silver, copper, aluminum, gold, magnesium oxide, tin oxide, bismuth oxide, and lead oxide.

Further, the resin composition of the present invention has an electrical conductivity of 0.001 Ω -1 cm -1 or more, preferably 0.0025 Ω ^-1 cm ^-1 or more, 0.005 Ω ^-1 cm ^-1 or more, 0.0025 Ω ^-1 cm ^-1 or more, .01Ω ⁻¹ cm ⁻¹ or more. Since the resin composition of the present invention contains inorganic filler particles coated with a coating having high electrical conductivity, the electrical conductivity of the resin composition can be increased, resulting in three-dimensional modeling with good electrical conductivity. It becomes easier to get things.

By the way, in general, the value of electrical conductivity and the value of thermal conductivity are closely related, and especially in the case of metal, the electrical conductivity and thermal conductivity are proportional. That is, materials with high electrical conductivity often have high thermal conductivity. Therefore, when the resin composition contains inorganic filler particles coated with a coating having electrical conductivity above a certain level, it can be expected that the resulting three-dimensional structure will have high thermal conductivity. Furthermore, since the electrical conductivity of the three-dimensional structure becomes high, it can be suitably used, for example, for internal parts of electrical products, especially parts that require electrical conductivity. Note that each material contained in the electrically conductive resin composition is the same as the thermally conductive material described above, and therefore a description thereof will be omitted.

Next, the three-dimensional structure of the present invention will be explained.

The three-dimensional structure of the present invention is preferably made of the resin composition of the present invention.

The three-dimensional structure of the present invention includes a resin and inorganic filler particles, and the surface of the inorganic filler particles is coated with a coating made of one or more types selected from metals, oxides, and nitrides. , characterized in that the thermal conductivity of the coating is 2 W/m·K or more.

Since the three-dimensional structure of the present invention contains inorganic filler particles coated with a coating having a thermal conductivity higher than a certain level, it can be expected that the three-dimensional structure also has high thermal conductivity. Therefore, when used, for example, as an internal component of an electrical product, the heat generated inside can be efficiently radiated to the outside. In addition, since each material contained in the three-dimensional structure is common to the resin composition described above, description thereof will be omitted here.

Furthermore, a three-dimensional structure according to another aspect of the present invention includes a resin and inorganic filler particles, and the surface of the inorganic filler particles is coated with one or more types selected from metals, oxides, and nitrides. The electrical conductivity of the coating is 0.01Ω ⁻¹ cm ⁻¹ or more.

Since the three-dimensional structure of the present invention contains inorganic filler particles coated with a coating having electrical conductivity above a certain level, it can be expected that the three-dimensional structure has high thermal conductivity. Furthermore, since the electrical conductivity of the three-dimensional structure is also high, it can be used, for example, for internal parts of electrical products that require electrical conductivity. Each material included in the three-dimensional structure is the same as those already described, so a description thereof will be omitted here.

Next, a method for manufacturing a three-dimensional structure according to the present invention will be explained. Note that the resin composition is as described above, and its explanation will be omitted here.

First, a first precursor layer made of a resin composition is formed. The precursor layer may be a photocurable resin, a thermosetting resin, or a thermoplastic resin, and may be cured according to the characteristics of each resin. In this way, the first layer is cured to form a cured layer.

Next, a new precursor layer made of a resin composition is formed on the cured layer. Then, by curing the new precursor layer, a new hardened layer having a predetermined pattern continuous with the hardened layer is formed.

Thereafter, a three-dimensional object is manufactured by repeating the lamination of the cured layers until a predetermined three-dimensional object is obtained.

Thereafter, at least a portion of the surface of the obtained three-dimensional structure may be machined, if necessary.

Next, a stereolithography method will be used as an example of the method for manufacturing a three-dimensional object of the present invention. Note that the resin composition is as described above, and its explanation will be 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 positioned so that the top surface of the stage is at a desired depth (for example, about 0.2 mm) from the liquid level. By doing so, a liquid layer with a thickness of about 0.1 to 0.2 mm can be prepared on the stage.

Next, this liquid layer is irradiated with active energy light, such as an ultraviolet laser, to cure the photocurable resin, thereby forming a cured layer having a predetermined pattern. In addition to ultraviolet rays, visible rays, infrared rays, and other laser beams can be used as active energy rays.

Subsequently, a new liquid layer made of a photocurable resin composition is prepared on the formed cured layer. For example, by lowering the above-described modeling stage by one layer, a photocurable resin can be introduced onto the cured layer to prepare a new liquid layer.

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

Thereafter, at least a portion of the surface of the obtained three-dimensional structure may be machined, if necessary.

The present invention will be described below based on examples.

First, inorganic filler particles having the materials and shapes shown in Table 1 were prepared. Thereafter, the inorganic filler particles were coated using the material described above to obtain coated inorganic filler particles.

For coating methods A to C, Ag particles listed in Table 1 were prepared as coatings, and inorganic filler particles and Ag particles were mixed and attached. Further, in D and E, an electroplating method was used in which inorganic filler particles were immersed in a plating solution for the coating. The adhesion weight of each coating was calculated by measuring the weight change before and after coating.

Table 2 shows Examples (No. 1 to 6) of the present invention and Comparative Example (No. 7). As the resin, polyphenylsulfone (PPS: continuous heat resistance temperature 240°C, density 1.8 g/cm ³ ) or polyetheretherketone (PEEK: continuous heat resistance temperature 240°C, density 1.3 g/cm ³ ) was prepared. Further, using the above-mentioned materials prepared as inorganic filler particles, the materials and proportions shown in Table 2 were kneaded using an injection molding machine and molded into pellets to obtain a homogeneous resin composition. These resin compositions were injection molded into a wire shape with a diameter of 1.75 mm, which was made into a filament and submitted to a three-dimensional modeling device to obtain a plate-shaped three-dimensional object with a thickness of 5 mm and a diameter of 30 mm.

Each characteristic was measured as follows.

Density was measured using the Archimedes method.

Thermal conductivity was measured by the laser flash method.

Electrical conductivity was measured by impedance method.

The heat resistance temperature was measured by the deflection method under load.

As can be seen from Table 2, No. 1 using inorganic filler particles coated with a coating having high thermal conductivity. Nos. 1 to 6 had high thermal conductivity of the three-dimensional structure. Also, No. In Nos. 1 to 6, the electrical conductivity of the three-dimensional structures was also high.

The resin composition of the present invention can be suitably used for three-dimensional modeling, particularly for three-dimensional modeling such as stereolithography, powder sintering, and fused modeling (FDM). Furthermore, the resin composition of the present invention can be formed into a sheet shape or any part shape, and used for electronic parts, consumer applications, etc. In particular, it can be suitably used in applications requiring thermal conductivity and electrical conductivity.

Claims (10)

A resin composition comprising a resin and inorganic filler particles,
The surface of the inorganic filler particles is coated with a coating consisting of one or more types selected from metals, oxides, and nitrides,
The thermal conductivity of the coating is 2 W/m·K or more,
The coating is fine particles,
The average particle diameter of the fine particles is 0.001 to 0.5 μm,
The aspect ratio (length/diameter) of the inorganic filler particles is 1.1 or more,
A resin composition characterized in that the inorganic filler particles have a diameter of 2.5 to 17.5 μm . The resin composition according to claim 1, wherein the inorganic filler particles are glass. The resin composition according to claim 2 , wherein the inorganic filler particles contain 50% by mass or more of SiO ₂ +Al ₂ O ₃ +B ₂ O ₃ +P ₂ O ₅ as a glass composition. The inorganic filler particles have, as a glass composition, SiO ₂ 10-85%, Al ₂ O ₃ 0-30%, B ₂ O ₃ 0-50%, P ₂ O ₅ 0-50%, R ₂ The resin composition according to claim 2 or 3 , characterized in that it contains 0 to 12% of O (R is at least one selected from Li, Na, and K). The resin composition according to any one of claims 1 to 4, wherein the coating has a heat resistance temperature of 200°C or higher. The resin composition according to any one of claims 1 to 5, wherein the density of the coating is 1.9 to 12.0 g/cm ³ . The resin composition according to any one of claims 1 to 6 , which has a thermal conductivity of 0.6 W/m·K or more. The resin composition according to any one of claims 1 to 7 , having an electrical conductivity of 0.001Ω ⁻¹ cm ⁻¹ or more. A three-dimensional object characterized by using the resin composition according to any one of claims 1 to 8 . By forming and curing a precursor layer made of a resin composition, a cured layer having a predetermined pattern is formed, and by forming and curing a new precursor layer on the cured layer, a predetermined pattern continuous with the cured layer is formed. A method for manufacturing a three-dimensional object by forming a new hardened layer having a pattern and repeating lamination of the cured layer until a predetermined three-dimensional object is obtained, the method comprising:
A method for producing a three-dimensional object, characterized in that the resin composition according to any one of claims 1 to 8 is used as the resin composition.