JP6883271B2 - Inorganic filler particles - Google Patents

Description

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

Conventionally, a method of laminating resin materials and the like to obtain a three-dimensional model has been known. For example, various methods such as a stereolithography method, a powder bed fusion sintering method, and a Fused deposition modeling (FDM) method have been proposed and put into practical use (see, for example, Patent Document 1).

Among them, the stereolithography method is excellent in delicate modeling and accurate size expression, and is widely used. The stereolithography method produces 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 active energy rays 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 photocurable resin is similarly irradiated with active energy rays. A new hardened layer is piled up on the hardened layer. By repeating this operation, a predetermined three-dimensional model is obtained. Further, in the powder sintering method, a modeling stage is provided in a tank filled with resin, metal, ceramics or glass powder, the powder on the modeling stage is irradiated with active energy rays, and a desired pattern is cured by softening and deformation. It forms a layer.

The three-dimensional model 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 obtained three-dimensional model is improved by containing the inorganic filler particles in the resin composition.

Japanese Unexamined Patent Publication No. 7-26060

In recent years, the uses of three-dimensional shaped objects made of resin compositions have been diversified, and they are being developed for applications that require aesthetics such as ornaments. Here, it is conceivable to add a pigment or the like in addition to the inorganic filler particles to the resin composition to obtain a dark-colored three-dimensional model. However, this method has a problem that the fluidity of the resin composition is lowered and the moldability is lowered. Further, in the case of the stereolithography method, since the pigment or the like blocks the active energy rays, there is a problem that the active energy rays are hard to spread throughout the resin composition and the curing becomes insufficient.

In view of the above, it is an object of the present invention to provide inorganic filler particles capable of efficiently producing a dark-colored three-dimensional model.

Inorganic filler particles of the present invention, the surface of the glass particles are deposited metal particles, Lightness (L ^* value) is equal to or is 90 or less.

Inorganic filler particles of the present invention, the metal particles adhering to the glass particle surface absorbs visible light, it has a feature of low light level. Therefore, by using the resin composition containing the inorganic filler particles of the present invention, it is possible to produce a three-dimensional model having a desired dark color. In this case, since it is not necessary to add a pigment or the like separately from the inorganic filler particles, there is an advantage that the fluidity of the resin composition does not unreasonably decrease and the moldability is excellent. Further, in the case of the stereolithography method, the active energy rays are less likely to be blocked by the pigment or the like, so that curing can be promoted.

In the inorganic filler particles of the present invention, it is preferable that the metal particles consist of at least one selected from Fe, Cr and Ni. In this way, desired low light level is easily obtained.

The inorganic filler particles of the present invention preferably have 200 μg or more of metal particles attached to 1 g of glass particles. In this way, desired low light level is easily obtained.

The inorganic filler particles of the present invention _{preferably have an average particle size (D 50} ) of glass particles of 1 μm or more. By doing so, the fluidity of the resin composition is excellent and the moldability is easily improved. In addition, bubbles (interfacial bubbles) existing at the interface between the inorganic filler particles and the resin are easily removed.

The resin composition of the present invention is characterized by containing the above-mentioned inorganic filler particles and a curable resin.

The three-dimensional model of the present invention is characterized by comprising a cured product of the above resin composition.

Three-dimensional object of the present invention, Lightness (L ^* value) is preferably 60 or less.

In the method for producing a three-dimensional model of the present invention, a surface layer made of a resin composition is selectively irradiated with active energy rays to form a cured layer having a predetermined pattern, and a new layer is formed on the cured layer. After that, a new cured layer having a predetermined pattern continuous with the cured layer is formed by irradiating with active energy rays, and the three-dimensional modeling is characterized by repeating the lamination of the cured layer until a predetermined three-dimensional model is obtained. It is a method for producing a product, and is characterized in that the above-mentioned resin composition is used as the resin composition.

By using the resin stop composition containing the inorganic filler particles of the present invention, it is possible to efficiently produce a dark-colored three-dimensional model.

The inorganic filler particles of the present invention are formed by adhering metal particles to the surface of glass particles.

The average particle size (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 obtained inorganic filler particles also become small, and when the inorganic filler particles of the present invention are mixed with the resin, the fluidity of the resin composition decreases or the inorganic filler particles It becomes difficult for bubbles (interfacial bubbles) existing at the interface between the resin and the resin to come off. On the other hand, if the average particle size of the glass particles is too large, the obtained inorganic filler particles also become large, and the filling rate of the inorganic filler particles in the resin composition tends to decrease. Therefore, 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 of the primary particles in terms of median diameter, and refers to a value measured by a laser diffraction type particle size distribution measuring device.

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. If the specific surface area of the glass particles is too small, the particle size 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 obtained inorganic filler particles also increases, so that the fluidity of the resin composition decreases or bubbles existing at the interface between the inorganic filler particles and the resin. Is hard to come off.

The shape of the glass particles is not particularly limited, but it is preferably substantially spherical. By doing so, since the specific surface area of the inorganic filler particles becomes small, it is possible to suppress an increase in the viscosity of the resin composition. The substantially spherical glass particles can be produced, for example, by crushing bulk glass and then performing flame polishing (fire polishing).

The softening point of the glass particles is preferably 1000 ° C. or lower, 900 ° C. or lower, and particularly preferably 800 ° C. or lower. If the softening point of the glass particles is too high, it tends to be difficult to spheroidize by flame polishing. On the other hand, the lower limit of the softening point of the glass particles is not particularly limited, but in reality, it is 250 ° C. or higher, particularly 300 ° C. or higher.

The crystallization start temperature of the glass particles is preferably 100 ° C. or higher, 150 ° C. or higher, and particularly preferably 200 ° C. or higher higher than the softening point. In this way, crystals are less likely to precipitate during the softening flow of the glass particles, so that spheroidization by flame polishing becomes easy.

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 tend to settle and separate in the resin composition when the stereolithography 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 the composition can be used. Specifically, SiO 2 -B 2 O 3 -R} '2 O (R' alkali metal element) based _{glass, SiO 2 -Al 2 O 3 -RO} (R is an alkaline earth metal element) based glass, SiO _{2 -Al 2 O 3 -R '2} O-RO -based _{glass, SiO 2 -Al 2 O 3 -B} 2 O 3 -R' 2 O -based _{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 and the like can be used. Hereinafter, a 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 devitrification resistance, the _{total amount of SiO 2} , Al ₂ O ₃ , B ₂ O ₃ and P ₂ O ₅ is 1% or more, 5% or more, particularly 10% or more. It is preferable to include it. However, since these components are components that reduce the density, when a high-density three-dimensional model is obtained, the total amount is preferably 50% or less, 40% or less, and particularly preferably 30% or less.

By using high-density glass particles, it is possible to give a profound feeling to the obtained three-dimensional model. From the viewpoint of increasing the density of glass particles, it is preferable that the glass composition contains elements having a relatively large atomic weight such as Ba, La, Gd, Ta, Nb, W, Bi and Te. For example, it is preferable to regulate the content of these oxides as follows.

The content of BaO is preferably 1% or more, 10% or more, 20% or more, and particularly preferably 30% or more. If the content of BaO is too large, it tends to be devitrified and vitrification tends to be difficult. Therefore, it is preferably 60% or less, particularly 50% or less.

The content of La ₂ O ₃ + Gd ₂ O ₃ + Ta ₂ O ₅ + Nb ₂ O ₅ + WO ₃ + Bi ₂ O ₃ + TeO ₂ is preferably 1% or more, 10% or more, and particularly preferably 20% or more. However, if the content of these components is too large, the raw material cost tends to be high, so 80% or less, 70% or less, particularly 60% or less is preferable. In addition, "La ₂ O ₃ + Gd ₂ O ₃ + Ta ₂ O ₅ + Nb ₂ O ₅ + WO ₃ + Bi ₂ O ₃ + TeO ₂ " means the total amount of the contents of each of these components.

From the viewpoint of the design of the three-dimensional model, when it is desired to increase the refractive index of the glass particles, it is preferable to contain _{TiO 2 having a high effect of improving the refractive index.} The content of TiO ₂ is preferably 0.1% or more, 1% or more, 5% or more, 10% or more, and particularly preferably 30% or more. However, _{if the content of TiO 2} is too large, the light transmittance may decrease and the design may be impaired. Therefore, the upper limit is preferably 50% or less, particularly 45% or less.

Sb ₂ O ₃ and Ce _{O 2} have an effect of suppressing a decrease in light transmittance due to the Fe component. The _{total content of Sb 2} O ₃ and Ce _{O 2} is preferably 0.01 to 1%, particularly 0.1 to 0.8%. If the content of these components is too small, it becomes difficult to obtain the above effect, while if it is too large, the light transmittance tends to decrease or the light is easily devitrified during molding. The contents of each of Sb ₂ O ₃ and CeO ₂ are also preferably within the above range.

The _{total content of Li 2} O, Na ₂ O and K ₂ O is preferably 5% or less, 2.5% or less, and particularly preferably 1% or less. If the content of these components is regulated as described above, evaporation of the alkaline component during resin curing can be suppressed. In addition, a decrease in chemical durability can be suppressed.

Further, for environmental reasons, the total content of fluorine, lead, antimony, arsenic, chlorine and sulfur is preferably 1% or less, 0.5% or less, and particularly preferably 0.1% or less.

The metal particles are not particularly limited, and examples thereof include at least one selected from Fe, Cr, and Ni. Because they easily absorb visible light, the desired low light level is easily obtained. The average particle size (D ₅₀ ) of the metal particles is usually 0.01 to 100 μm, more preferably 0.1 to 10 μm.

In the inorganic filler particles of the present invention, it is preferable that 200 μg or more, 500 μg or more, 750 μg or more, 1000 μg or more, particularly 1500 μg or more, of metal particles are attached to 1 g of glass particles. If the amount of deposition of the metal particles is too small, the absorption of visible light is insufficient, the desired light level is hardly obtained. On the other hand, if the amount of metal particles adhered is too large, the fluidity of the resin composition is unreasonably lowered, and the moldability tends to be poor. Further, in the case of the stereolithography method, the active energy rays may be blocked by the metal particles, making it difficult to cure. Therefore, the amount of metal particles attached is preferably 5000 μg or less, 4000 μg or less, and particularly 3000 μg or less with respect to 1 g of glass particles.

The metal particles are attached to the surface of the glass particles by mixing the glass particles and the metal particles. By mixing the two while heating at 100 ° C. or higher, 200 ° C. or higher, and further 300 ° C. or higher, the metal particles can be easily adhered firmly to the surface of the glass particles. In addition, metal particles may be added when the bulk glass as a raw material is crushed or classified. In this way, the metal particles can be attached at the same time as the glass is pulverized or classified, so that the production efficiency is improved. Glass powder to, when performing the spheroidizing treatment by flame polishing, in order to suppress the bright degree increase by oxidation of the metal particles, after the spheroidization treatment, it is preferable to deposit the metal particles in the glass particles.

Lightness of the inorganic filler particles of the present invention (L ^* value) is 90 or less, 88 or less, and particularly preferably 85 or less. When light of the inorganic filler particles is too high, three-dimensional object exhibiting desired dark color is hardly obtained.

The surface of the inorganic filler particles of the present invention is preferably treated with a silane coupling agent. In this way, the bonding force between the inorganic filler particles and the resin can be enhanced, and it becomes possible to obtain a three-dimensional model having more excellent mechanical strength. As the silane coupling agent, for example, aminosilane, epoxysilane, acrylicsilane and the like are preferable. The type of silane coupling agent may be appropriately selected according to the curable resin to be used. For example, when a vinyl-based unsaturated compound is used as the photocurable resin, an acrylic silane-based silane coupling agent or an epoxy-based compound may be used. When 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 10 to 99% of the curable resin and 1 to 90% of the inorganic filler particles in a volume%. 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%. If the content of the inorganic filler particles is too small, it becomes difficult to obtain the effect of improving the mechanical strength of the obtained three-dimensional model. On the other hand, when the content of the inorganic filler particles is too large, the contact area of each inorganic filler particle with the curable resin tends to be small, and the mechanical strength of the obtained three-dimensional model tends to be rather low. Further, in the case of the stereolithography method, the viscosity of the resin composition becomes too high, and problems such as difficulty in forming a new liquid layer on the molding stage are likely to occur.

Since the inorganic filler particles of the present invention can easily enjoy the effect particularly in the case of the stereolithography method, it is preferable to use a photocurable resin (liquid photocurable resin) as the curable resin.

As the photocurable resin, various resins such as a polymerizable vinyl compound and an epoxy compound can be selected. Further, 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 the monofunctional compound of the polymerizable vinyl compound include isobornyl acrylate, isobornyl methacrylate, dincropentenyl acrylate, borneyl acrylate, bornyl methacrylate, 2-hydroxyethyl acrylate, 2-hydroxypropyl acrylate, and propylene glycol. Examples thereof include acrylate, vinylpyrrolidone, acrylamide, vinyl acetate and styrene. Examples of the polyfunctional compound include trimethyl propanetriacrylate, EO-modified trimethylpropantriacrylate, ethylene glycol diacrylate, tetraethylene glycol diacrylate, polyethylene glycol diacrylate, 1,4-butanediol diacrylate, and 1,6. -Hexanediol diacrylate, neopentyl glycol diacrylate, dicyclopentenyl diacrylate, polyester diacrylate, diallyl phthalate and the like can be mentioned. One or more of these monofunctional compounds and polyfunctional compounds can be used alone or in the form of a mixture.

As the polymerization initiator of the vinyl compound, a photopolymerization initiator is used. Photopolymerization initiators include 2,2-dimethoxy-2-phenylacetophenone, 1-hydroxycyclohexylphenylketone, acetophenone, benzophenone, xantone, fluorenone, benzaldehyde, fluorene, anthraquinone, triphenylamine, carbazole, 3-methylacetophenone, Michler ketone and the like can be mentioned as typical examples, and one or a combination of two or more of these initiators can be used. If necessary, a sensitizer such as an amine compound can be used in combination. The amount of these polymerization initiators used is preferably 0.1 to 10% by mass, respectively, with respect to the vinyl compound.

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

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

Next, an example of a method for manufacturing a three-dimensional model will be described. Specifically, a method for producing a three-dimensional model using a resin composition containing a photocurable resin will be described. The resin composition is as described above, and description thereof will be omitted here.

First, a single 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 upper surface of the stage is positioned so as to have a desired depth (for example, about 0.2 mm) from the liquid surface. By doing so, a liquid layer can be prepared on the stage.

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

Subsequently, a new liquid layer made 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, and a new liquid layer can be prepared.

Then, the 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.

By repeating the above operation, the cured layers are continuously laminated to obtain a predetermined three-dimensional model.

By using the resin composition containing the inorganic filler particles of the present invention, it is possible to produce a three-dimensional model having a desired dark color. For example, when the inorganic filler particles of the present invention are blended in a resin composition in an amount of 30% by volume, a brightness L ^* of 60 or less, particularly 50 or less can be achieved.

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

(Example 1)
(Preparation of inorganic filler particles)
By _{mass%, SiO 2 52%, B} 2 O 3 7%, Al 2 O 3 14%, 0.5% MgO, CaO 25%, Na 2 O 0.6%, K 2 O 0.1%, TiO _The raw materials were prepared so as to have a glass composition of 20.5% 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-shaped glass, glass particles having an average particle diameter of 10 μm (softening point 800 ° C.) were obtained. This glass was beaded by a flame method and classified by a nylon sieve. Inorganic filler particles were obtained by mixing metal particles containing Fe, Cr and Ni with the obtained glass particles. When the obtained inorganic filler particles were analyzed, 1605 μg of metal particles (Fe 1500 μg, Cr 100 μg, Ni 5 μg) were attached to 1 g of glass particles.

The resulting inorganic filler particles was 85 was measured Lightness L ^* value with a color difference meter.

(Preparation of photocurable resin)
First, isophorone diisocyanate, morpholine acrylamide and dibutyl tin dilaurate were heated in an oil bath. A solution prepared by uniformly mixing and dissolving methylhydroquinone in glycerin monomethacrylate monoacrylate was added, and the mixture was stirred and mixed for reaction. A reaction product containing urethane acrylate oligomer and morpholine acrylamide was produced by adding 4 mol adducts of pentaerythritol propylene oxide (1 mol adduct of propylene oxide added to each of the 4 hydroxyl groups of pentaerythritol) and reacting them.

Morpholine acrylamide and dicyclopentanyl diacrylate were added to the obtained urethane acrylate oligomer and morpholine acrylamide. Further, 1-hydroxycyclohexylphenyl 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)
To 70% by volume of the photocurable resin obtained above, 30% by volume of inorganic filler particles were added and kneaded with three rollers to obtain a paste-like resin composition in which the inorganic filler particles were uniformly dispersed. Obtained. The obtained resin composition was poured into a Teflon-made mold having an inner size of 30 mm □. Then, the resin composition was cured by irradiating with light having a wavelength of 500 mW and a wavelength of 364 nm, and then annealed at 80 ° C. to obtain a three-dimensional model. ^{The brightness L *} value of the obtained three-dimensional model was measured using a color difference meter and found to be 40.

(Example 2)
Inorganic filler particles were obtained in the same manner as in Example 1 except that metal particles having different contents of Fe, Cr and Ni from Example 1 were mixed with the obtained glass particles. When the obtained inorganic filler particles were analyzed, 1917 μg of metal particles (Fe 1800 μg, Cr 110 μg, Ni 7 μg) were attached to 1 g of the glass particles. ^{The brightness L *} value of the obtained inorganic filler particles was measured and found to be 84. Further, a three-dimensional model was produced using the inorganic filler particles by the same method as in the example, and the brightness L ^* value was measured and found to be 37.

(Comparison example)
The glass particles obtained in Example 1 were used as they were as inorganic filler particles without mixing the metal particles. ^{The brightness L *} value of the inorganic filler particles was measured and found to be 91. Further, a three-dimensional model was produced using the inorganic filler particles by the same method as in the example, and the brightness L ^* value was measured and found to be 61.

Claims (7)

On the surface of the glass particles are deposited metal particles, Lightness (L ^* value) of an inorganic filler particles, characterized in that it is 90 or less,
Inorganic filler particles in which 200 to 5000 μg of metal particles are attached to 1 g of glass particles. The inorganic filler particles according to claim 1, wherein the metal particles consist of at least one selected from Fe, Cr and Ni. The inorganic filler particles according to claim 1 or 2, wherein the average particle size (D _{50) of the glass particles is 1 μm or more.} Resin composition characterized by containing an inorganic filler particles and the photo-curable resin according to any one of claims 1 to 3. A three-dimensional model comprising a cured product of the resin composition according to claim 4. Lightness (L ^* value) of the three-dimensional object according to claim 5, characterized in that 60 or less. The surface layer made of the resin composition is selectively irradiated with active energy rays to form a cured layer having a predetermined pattern, a new layer is formed on the cured layer, and then the active energy rays are irradiated to cure the cured layer. A method for producing a three-dimensional model, which comprises forming a new cured layer having a predetermined pattern continuous with the layer and repeating the lamination of the cured layer until a predetermined three-dimensional model is obtained. A method for producing a three-dimensional model, which comprises using the resin composition according to claim 4.