Active energy ray curable composition for inkjet, method for producing three-dimensional object, and device for producing three-dimensional object

Abstract

To provide an inkjet active-energy-ray-curable composition that has good inkjet dischargeability and can produce a cured product having a high elastic modulus, a high strength, and a high hardness.SOLUTION: Provided is an inkjet active-energy-ray-curable composition including a bisphenol-type methacrylate, a low-viscosity monomer, and an inorganic filler.SELECTED DRAWING: None

Description

[Technical field]

[0001] The present invention relates to an active energy ray-curable composition for inkjet, a method for producing a three-dimensional object, and an apparatus for producing a three-dimensional object. [Background technology]

[0002] In recent years, among three-dimensional additive manufacturing technologies, the material jetting method (hereinafter sometimes referred to as the "MJ method") has attracted attention, in which an active energy ray-curable composition is placed at a required location using an inkjet head and the placed active energy ray-curable composition is cured using a light irradiation device or the like to form a three-dimensional solid object.

[0003] The MJ method requires that the cured product of the active energy ray curable composition has various properties such as strength, hardness, and elastic modulus. As a method for improving these properties, a method of adding an inorganic filler to the active energy ray curable composition has been attempted. In addition, application to biomaterials including dental materials has also been considered, and there is a demand for designing an active energy ray curable composition using a biocompatible monomer. For example, an active energy ray-curable composition has been proposed which contains a monofunctional polymerizable monomer having one ethylenically unsaturated double bond and inorganic particles having a reactive organic group, in which the content of the monofunctional monomer is 80 mass% or more based on the total amount of the polymerizable compound, and the reactive organic group of the inorganic particle has an ethylenically unsaturated double bond (see, for example, Patent Document 1).

[0004] Furthermore, as a highly biocompatible monomer component, for example, bisphenol A diglycidyl methacrylate (Bis-GMA) is used to increase hardness and elastic modulus. Summary of the Invention [Problem to be solved by the invention]

[0005] An object of the present invention is to provide an active energy ray-curable composition for inkjet printing that has good inkjet ejection properties and is capable of forming a cured product having high elastic modulus, high strength, and high hardness. [Means for solving the problem]

[0006] The active energy ray-curable composition for inkjet of the present invention as a means for solving the above problems comprises a bisphenol methacrylate and Methacrylate with a viscosity of 100 mPa s or less at 25°C Contains low viscosity monomer and inorganic filler The mass ratio (A:B) of the monomer component (A) to the inorganic filler (B) is 80:20 to 40:60, and the viscosity in a 25°C environment is 600 mPa·s or less. do. Effect of the Invention

[0007] According to the present invention, it is possible to provide an active energy ray-curable composition for inkjet printing that has good inkjet ejection properties and can form a cured product that has high elasticity, high strength, and high hardness. [Brief description of the drawings]

[0008] [Figure 1] FIG. 1 is a schematic diagram showing an example of an apparatus for producing a three-dimensional object according to the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0009] (Active energy ray curable composition for inkjet) The active energy ray-curable composition for inkjet of the present invention contains a bisphenol methacrylate, a low viscosity monomer, and an inorganic filler, and further contains other components as required.

[0010] The "active energy ray-curable composition for inkjet printing" is a composition that is discharged by an inkjet method and cured by being irradiated with active energy rays to form a cured product. In the present invention, "hardening" refers to the formation of a polymer, but is not limited to solidification, and also includes cases where the viscosity increases and where both solidification and thickening occur. In addition, the term "solidified material (hardened material)" refers to a polymer, but is not limited to solids, and also includes thickened materials and mixtures of solids and thickened materials.

[0011] In the conventional technology, when an active energy ray-curable composition contains an inorganic filler at a high concentration, the viscosity increases significantly, which makes it difficult to eject the composition by an inkjet method. Furthermore, bisphenol A diglycidyl methacrylate (Bis-GMA), which has traditionally been used as a highly biocompatible monomer component, has a high viscosity of 1,200,000 mPa s at 25°C, and even if an inorganic filler is further added to improve hardness and the composition is diluted with a diluent, it is difficult to achieve a low viscosity at a level that allows inkjet ejection. On the other hand, if the amount of diluent added is increased too much, the content of Bis-GMA in the active energy ray-curable composition decreases, and the curing reaction does not proceed.

[0012] Therefore, the active energy ray-curable composition for inkjet of the present invention contains bisphenol methacrylate, a low-viscosity monomer, and an inorganic filler, and therefore even if the inorganic filler is contained at a high concentration, the composition of the monomer components is optimized and the composition has low viscosity, and it is possible to form a cured product that has good inkjet ejection properties and combines high elastic modulus, high strength, and high hardness at both the top and bottom in the stacking direction, regardless of the stacking position.

[0013] The active energy ray-curable composition for inkjet of the present invention contains a monomer component including a bisphenol type methacrylate and a low viscosity monomer, an inorganic filler, and preferably contains a polymerization initiator, and further contains other components as necessary.

[0014] <Monomer component> The monomer component contains a bisphenol type methacrylate and a low viscosity monomer, and further contains other monomers as required.

[0015] -Bisphenol methacrylate- Examples of bisphenol type methacrylates include bisphenol A type methacrylate, bisphenol F type methacrylate, bisphenol S type methacrylate, etc. Among these, bisphenol A type methacrylate is preferred from the viewpoints of availability and mechanical properties of the cured product. Examples of bisphenol A methacrylates include bisphenol A monomethacrylate, bisphenol A dimethacrylate, trifunctional or higher bisphenol A methacrylates, etc. Among these, bisphenol A dimethacrylate is preferred from the viewpoints of availability and mechanical properties of the cured product. The bisphenol A dimethacrylate may be ethoxylated bisphenol A dimethacrylate, etc. Among these, ethoxylated bisphenol A dimethacrylate having a viscosity of 2,000 mPa·s or less at 25° C. is preferred. The viscosity at 25°C can be measured by a conventional method, for example, a cone-plate type rotational viscometer VISCOMETER TVE-22L manufactured by Toki Sangyo Co., Ltd., using a cone rotor (1°34' x R24) at a rotation speed of 50 rpm and a constant temperature circulating water temperature of 25°C. As the ethoxylated bisphenol A dimethacrylate having a viscosity of 2,000 mPa s or less at 25° C., a commercially available product can be used, and examples of the commercially available product include BPE-100 / D-2.6E (manufactured by Shin-Nakamura Chemical Co., Ltd.) and BPE-500 (manufactured by Shin-Nakamura Chemical Co., Ltd.). The content of the bisphenol type methacrylate is preferably from 10% by mass to 80% by mass, more preferably from 20% by mass to 70% by mass, based on the total amount of the active energy ray-curable composition for inkjet.

[0016] -Low viscosity monomer- In the present invention, the low viscosity monomer means a methacrylate having a viscosity at 25° C. of 100 mPa·s or less. The viscosity at 25° C. was measured by the same method as above. Examples of methacrylates include monomethacrylates, dimethacrylates, trifunctional or higher methacrylates, etc. Among these, dimethacrylates are preferred from the viewpoints of availability and mechanical properties of the cured product. The dimethacrylate is preferably at least one selected from ethylene glycol dimethacrylate (n=1), diethylene glycol dimethacrylate (n=2), and triethylene glycol dimethacrylate (n=3), which are represented by the following general formula (1).

[0017] [ka]

[0018] The mass ratio (a1:a2) of the content (a1) of the bisphenol methacrylate to the content (a2) of the low-viscosity monomer is preferably from 70:30 to 30:70, and more preferably from 60:40 to 40:60. In general, the termination reaction in radical polymerization occurs between two molecules of growing radicals. As the polymerization of the monomer components progresses and the polymer grows, the viscosity of the polymerization system also increases, and the chain termination reaction rate becomes significantly smaller. In addition, as the degree of polymerization of the polymer increases, the polymerization rate increases significantly. Therefore, in the present invention, the mass ratio (a1:a2) of the content (a1) of the bisphenol type methacrylate to the content (a2) of the low-viscosity monomer is 70:30 to 30:70, and the mass ratio of the bisphenol type methacrylate is not reduced too much, that is, the viscosity of the polymerization system is not reduced too much until the middle of the radical reaction, thereby suppressing the progress of the termination reaction in radical polymerization.

[0019] In the present invention, it is preferable that the curing time required for the storage modulus of the monomer component to reach 1 MPa, measured under the conditions of a photorheometer device: MCR302 (manufactured by Anton Paar), a light source: EXECURE-H-1VC II (manufactured by HOYA Corporation), a head unit: H-1 VH-V2 (manufactured by HOYA Corporation), a wavelength of 385 nm, a maximum output of 400 mW, and an intensity of 1, is within 10 seconds. It is preferable that the curing time required for the storage modulus of the monomer component to reach 1 MPa, as measured with a photorheometer at a wavelength of 385 nm, is within 10 seconds, since this provides sufficient curability without reducing productivity in the MJ method and provides a cured product that has no difference in hardness between the top and bottom in the stacking direction, regardless of the stacking position.

[0020] <Inorganic filler> The inorganic filler is not particularly limited and can be appropriately selected according to the purpose, and examples thereof include alumina, talc, silica, titania, zirconia, magnesium silicate, mica, glass fiber, glass beads, carbon black, carbon fiber, and aluminum balls. These may be used alone or in combination of two or more. Among these, silica, alumina, titania, and zirconia are preferred.

[0021] The inorganic filler is preferably surface-modified with a silane coupling agent. The silane coupling agent is not particularly limited and can be appropriately selected depending on the purpose. Examples of the silane coupling agent include vinyl methoxysilane, vinyl ethoxysilane, 2-(3,4-epoxycyclohexyl)ethyl trimethoxysilane, 3-glycidoxypropyl methyl dimethoxysilane, 3-glycidoxypropyl trimethoxysilane, 3-glycidoxypropyl methyl diethoxysilane, 3-glycidoxypropyl triethoxysilane, styryl p-Styryltrimethoxysilane, 3-methacryloxypropylmethyldimethoxysilane, 3-methacryloxypropyltrimethoxysilane, 3-methacryloxypropylmethyldiethoxysilane, 3-methacryloxypropyltriethoxysilane, 3-acryloxypropyltrimethoxysilane, N-2-(aminoethyl)-3-aminopropylmethyldimethoxysilane, N-2-(aminoethyl)-3-aminopropylmethyldimethoxysilane, 3-aminopropyltrimethoxysilane, 3-aminopropyltriethoxysilane, 3-triethoxy Examples of the silyl-N-(1,3-dimethyl-butylidene)propylamine include N-phenyl-3-aminopropyltrimethoxysilane, N-(vinylbenzyl)-2-aminoethyl-3-aminopropyltrimethoxysilane hydrochloride, tris-(trimethoxysilylpropyl)isocyanurate, 3-ureidopropyltrialkoxysilane, 3-mercaptopropylmethyldimethoxysilane, 3-mercaptopropyltrimethoxysilane, 3-isocyanatepropyltriethoxysilane, and 3-trimethoxysilylpropylsuccinic anhydride. These may be used alone or in combination of two or more. Among these, vinylmethoxysilane, 3-methacryloxypropylmethyldimeth silane, 3-acryloxypropyltrimethoxysilane, etc. Silane coupling agents having the formula:

[0022] It is preferable that the inorganic filler is spherical in terms of dispersibility and inkjet ejection properties. "Spherical" is not limited to a perfect sphere, but may include shapes such as a spheroid or polyhedron. For example, a particle in which the longest diameter (major axis) from the center point of the particle to the outer periphery of the particle is about twice as long as the shortest diameter (minor axis) is included in the "spherical" shape of the present invention, without being limited thereto. The ratio of the minor axis to the major axis is preferably 1:1 to 1:5, and more preferably 1:1 to 1:2. The volume average primary particle size of the inorganic filler is preferably 10 nm or more and 500 nm or less, and more preferably 100 nm or more and 300 nm or less. The volume average primary particle size can be measured, for example, by dynamic light scattering using an ELS-Z made by Otsuka Electronics Co., Ltd., and a dispersion of inorganic filler diluted 100 times with 2-methoxy-1-methylethyl acetate.

[0023] In the present invention, the mass ratio (A:B) of the monomer component (A) to the inorganic filler (B) is from 90:10 to 40:60, preferably from 80:20 to 40:60, and more preferably from 70:30 to 50:50. When the mass ratio (A:B) of the monomer component (A) to the inorganic filler (B) is 90:10 to 40:60, a cured product can be formed that has good ink-jet ejection properties while also having a high elastic modulus, high strength, and high hardness.

[0024] <Polymerization initiator> As the polymerization initiator, any substance that generates radicals when irradiated with light (particularly ultraviolet light having a wavelength of 220 nm to 400 nm) can be used. Examples of the polymerization initiator include acetophenone, 2,2-diethoxyacetophenone, p-dimethylaminoacetophenone, benzophenone, 2-chlorobenzophenone, p,p'-chlorobenzophenone, p,p-bisdiethylaminobenzophenone, Michler's ketone, benzil, benzoin, benzoin methyl ether, benzoin ethyl ether, benzoin isopropyl ether, benzoin-n-propyl ether, benzoin isobutyl ether, benzoin-n-butyl ether, benzyl methyl ketal, thioxanthone, 2-chlorothioxanthone, 2-hydroxy-2-methyl-1-phenyl-1-one, 1-(4-isopropylphenyl)2-hydroxy-2-methylpropan-1-one, methylbenzoyl formate, 1-hydroxycyclohexyl phenyl ketone, azobisisobutyronitrile, benzoyl peroxide, and di-tert-butyl peroxide. These may be used alone or in combination of two or more. The content of the polymerization initiator is preferably from 0.1% by mass to 10.0% by mass, more preferably from 1.0% by mass to 5.0% by mass, based on the total amount of the active energy ray-curable composition for inkjet.

[0025] <Other ingredients> The other components are not particularly limited and can be appropriately selected depending on the purpose. Examples of the other components include surfactants, polymerization inhibitors, colorants, viscosity modifiers, antioxidants, antiaging agents, crosslinking accelerators, ultraviolet absorbers, plasticizers, preservatives, solvents, and dispersants.

[0026] -Surfactants- The surfactant is preferably, for example, a compound having a molecular weight of 200 to 5000, and specific examples thereof include PEG-type nonionic surfactants [nonylphenol with 1 to 40 mol of ethylene oxide (hereinafter abbreviated as EO), stearic acid with 1 to 40 mol of EO, etc.], polyhydric alcohol-type nonionic surfactants (sorbitan palmitic acid monoester, sorbitan stearic acid monoester, sorbitan stearic acid triester, etc.), fluorine-containing surfactants (perfluoroalkyl EO with 1 to 50 mol of EO, perfluoroalkyl carboxylate, perfluoroalkyl betaine, etc.), modified silicone oils [polyether-modified silicone oils, (meth)acrylate-modified silicone oils, etc.], etc. These may be used alone or in combination of two or more.

[0027] -Polymerization inhibitor- Examples of the polymerization inhibitor include phenol compounds [hydroquinone, hydroquinone monomethyl ether, 2,6-di-t-butyl-p-cresol, 2,2-methylene-bis-(4-methyl-6-t-butylphenol), 1,1,3-tris-(2-methyl-4-hydroxy-5-t-butylphenyl)butane, etc.], sulfur compounds [dilauryl thiodipropionate, etc.], phosphorus compounds [triphenyl phosphite, etc.], amine compounds [phenothiazine, etc.], etc. These may be used alone or in combination of two or more.

[0028] -Coloring materials- As the coloring material, a dye or pigment that is dissolved or stably dispersed in the active energy ray curable composition for inkjet and has excellent thermal stability is suitable. Among these, a soluble dye (solvent dye) is preferable. In addition, two or more kinds of coloring materials may be appropriately mixed to adjust the color, etc.

[0029] <Method for preparing active energy ray-curable composition for inkjet printing> The active energy ray-curable composition for inkjet can be prepared using the various components described above. The preparation means and conditions are not particularly limited. For example, the composition can be prepared by putting the bisphenol methacrylate, the low viscosity monomer, the inorganic filler, and other components into a dispersing machine such as a ball mill, a Kitty mill, a disk mill, a pin mill, or a Dyno mill, and dispersing the components.

[0030] [Physical properties of active energy ray-curable composition for inkjet printing] In view of ejection properties from a nozzle, it is preferable that an active energy ray-curable composition for inkjet that can be suitably used in an inkjet system has a low viscosity. Therefore, in one embodiment, the viscosity of the active energy ray-curable composition for inkjet of the present invention is preferably 600 mPa·s or less, more preferably 300 mPa·s or less, and even more preferably 200 mPa·s or less, in a 25°C environment. In view of ejection properties and modeling accuracy, it is preferable that the viscosity is 10 mPa·s or more in a 25°C environment. Note that, during modeling, the viscosity of the active energy ray-curable composition for inkjet can be adjusted by adjusting the temperature of the inkjet head or the flow path. The viscosity can be measured, for example, by a cone-plate type rotational viscometer VISCOMETER TVE-22L manufactured by Toki Sangyo Co., Ltd., using a cone rotor (1°34'×R24) at a rotation speed of 50 rpm and a constant temperature circulating water temperature of 25°C.

[0031] Moreover, from the viewpoints of ejection stability and modeling accuracy, the active energy ray-curable composition that can be used for inkjet applications preferably has a static surface tension of 20 mN / m or more and 40 mN / m or less in a 25° C. environment. The static surface tension can be measured by a conventional method, such as the plate method, the ring method, or the pendant drop method.

[0032] The active energy ray-curable composition for inkjet of the present invention can be suitably used for inkjet applications, particularly for the production of a three-dimensional object by inkjet. Therefore, the present invention also includes a three-dimensional object formed using the active energy ray-curable composition for inkjet of the present invention.

[0033] (Method and device for manufacturing three-dimensional object) The method for producing a three-dimensional object of the present invention includes a discharge step of discharging the active energy ray-curable composition for inkjet of the present invention, and a curing step of irradiating the discharged active energy ray-curable composition for inkjet with active energy rays to cure the composition, and further includes other steps as necessary. The apparatus for manufacturing a three-dimensional object of the present invention includes a discharge means for discharging the active energy ray-curable composition for inkjet of the present invention, and a curing means for curing the discharged active energy ray-curable composition for inkjet by irradiating it with active energy rays, and further includes other means as necessary.

[0034] <Discharge Process and Discharge Means> The ejection step is a step of ejecting the active energy ray-curable composition for inkjet according to the present invention, and is carried out by an ejection device. The ejection means is a means for ejecting the active energy ray-curable composition for inkjet recording of the present invention. In the ejection step, the active energy ray-curable composition for inkjet of the present invention is preferably ejected by an inkjet method onto a stage having a lifting function. The active energy ray-curable composition for inkjet ejected onto the stage forms a liquid film.

[0035] <Curing process and curing means> The curing step is a step of curing the discharged active energy ray-curable composition for inkjet by irradiating the composition with active energy rays. The curing means is a means for curing the discharged active energy ray-curable composition for inkjet by irradiating the composition with active energy rays. In the curing step, the liquid film made of the active energy ray curable composition for inkjet formed on the stage is cured by irradiating it with active energy rays.

[0036] -Active energy rays- The active energy ray used to cure the active energy ray curable composition for inkjet is preferably light, and particularly preferably ultraviolet rays having a wavelength of 220 nm to 400 nm. In addition to ultraviolet rays, electron beams, α rays, β rays, γ rays, X-rays, and the like may be used as long as they can provide the energy required to promote the polymerization reaction of the polymerizable components in the composition, and are not particularly limited. In particular, when a high-energy light source is used, the polymerization reaction can be promoted without using a polymerization initiator. In addition, in the case of ultraviolet irradiation, mercury-free is strongly desired from the viewpoint of environmental protection, and replacement with a GaN-based semiconductor ultraviolet light-emitting device is very useful industrially and environmentally. Furthermore, ultraviolet light-emitting diodes (UV-LEDs) and ultraviolet laser diodes (UV-LDs) are small, have a long life, are highly efficient, and are low cost, and are therefore preferable as ultraviolet light sources.

[0037] In the method for producing a three-dimensional object of the present invention, the discharging step and the curing step are sequentially repeated to produce a three-dimensional object of a desired shape.

[0038] Hereinafter, a method for forming a three-dimensional object and an apparatus for producing a three-dimensional object will be described in which the active energy ray-curable composition for inkjet according to the present invention is used as a model portion forming material.

[0039] Here, FIG. 1 is a schematic diagram showing an example of a manufacturing apparatus for a three-dimensional object of the present invention. The manufacturing apparatus 30 for a three-dimensional object of FIG. 1 includes head units 31 and 32, an ultraviolet irradiator 33, a roller 34, a carriage 35, and a stage 37. The head unit 31 discharges a model portion forming material 1. The head unit 32 discharges a support portion forming material 2. The ultraviolet irradiator 33 irradiates the discharged model portion forming material 1 and the support portion forming material 2 with ultraviolet light to harden them. The roller 34 smoothes the liquid film of the model portion forming material 1 and the support portion forming material 2. The carriage 35 reciprocates each of the means such as the head units 31 and 32 in the X direction in FIG. 1. The stage 37 moves the substrate 36 in the Z direction shown in FIG. 1 and in the Y direction, which is the depth direction in FIG. 1. The movement in the Y direction may be performed by the carriage 35 instead of the stage 37.

[0040] When there are multiple model portion forming materials for each color, multiple head units 31 for discharging the model portion forming materials of each color may be provided in the three-dimensional object manufacturing apparatus 30. As the nozzles in the head units 31 and 32, nozzles in a known inkjet printer can be suitably used.

[0041] Examples of metals that can be used for the roller 34 include SUS300, SUS400, SUS600, hexavalent chromium, silicon nitride, and tungsten carbide. Any of these metals coated with fluorine or silicone may also be used for the roller 34. Among these metals, SUS600 is preferred in terms of strength and workability. When the rollers 34 are used, the three-dimensional object manufacturing apparatus 30 stacks the layers while lowering the stage 37 according to the number of layers to keep a constant gap between the rollers 34 and the surface of the object. It is preferable that the rollers 34 are configured adjacent to the ultraviolet irradiator 33.

[0042] Furthermore, in order to prevent the ink from drying out during rest, the three-dimensional object manufacturing apparatus 30 may be provided with a means such as a cap for closing the nozzles of the head units 31 and 32. Furthermore, in order to prevent the nozzles from clogging during long periods of continuous use, the three-dimensional object manufacturing apparatus 30 may be provided with a maintenance mechanism for maintaining the heads.

[0043] Hereinafter, a modeling process performed by the apparatus for manufacturing a three-dimensional object according to the present invention will be described. The engine of the three-dimensional object manufacturing apparatus 30 ejects droplets of the model part forming material 1 from the head unit 31 and ejects droplets of the support part forming material 2 from the head unit 32 based on the two-dimensional data showing the cross section on the bottom side of the input two-dimensional data while moving the carriage 35 or the stage 37. As a result, the droplets of the model part forming material 1 are arranged at positions corresponding to the pixels showing the model part in the two-dimensional data showing the cross section on the bottom side, and the droplets of the support part forming material 2 are arranged at positions corresponding to the pixels showing the support part, and a liquid film is formed in which the droplets at adjacent positions are in contact with each other. In addition, when one object is to be molded, a liquid film with a cross-sectional shape is formed in the center of the stage 37. In the case of molding a plurality of objects, the three-dimensional object manufacturing apparatus 30 may form a plurality of liquid films with a cross-sectional shape on the stage 37, or may stack liquid films on objects previously molded.

[0044] It is preferable to install heaters in the head units 31 and 32. Furthermore, it is preferable to install preheaters in the path for supplying the model portion forming material to the head unit 31 and in the path for supplying the support portion forming material to the head unit 32.

[0045] In the smoothing step, the roller 34 scrapes off excess parts of the model part forming material and the support part forming material discharged onto the stage 37, thereby smoothing out the unevenness of the liquid film or layer made of the model part forming material and the support part forming material. The smoothing step may be performed once for each lamination in the Z-axis direction, or once for every 2 to 50 laminations. In the smoothing step, the roller 34 may be stopped, or may rotate at a positive or negative relative speed with respect to the traveling direction of the stage 37. The rotation speed of the roller 34 may be a constant speed, a constant acceleration, or a constant deceleration. The rotation speed of the roller 34 is preferably 50 mm / s or more and 400 mm / s or less as the absolute value of the relative speed with the stage 37. If the relative speed is too small, the smoothing is insufficient and the smoothness is impaired. If the relative speed is too large, the device must be large, and the position of the discharged droplets is easily shifted due to vibration, etc., which may result in a decrease in smoothness. In the smoothing step, the rotation direction of the roller 34 is preferably opposite to the moving direction of the head units 31 and 32 .

[0046] In the curing step, the engine of the three-dimensional object manufacturing apparatus 30 moves the ultraviolet irradiator 33 by the carriage 35, and irradiates the liquid film formed in the discharging step with ultraviolet light according to the wavelength of the photopolymerization initiator contained in the model portion forming material and the support portion forming material. In this way, the three-dimensional object manufacturing apparatus 30 cures the liquid film to form a layer.

[0047] After the bottommost layer is formed, the engine of the apparatus 30 for manufacturing a three-dimensional object lowers the stage by the distance of one layer. The engine of the three-dimensional object manufacturing apparatus 30 ejects droplets of the model portion forming material 1 and ejects droplets of the support portion forming material 2 based on the two-dimensional image data showing the second cross section from the bottom side while moving the carriage 35 or the stage 37. The ejection method is the same as when forming the liquid film on the bottommost side. As a result, a liquid film having a cross-sectional shape shown by the second two-dimensional data from the bottom side is formed on the bottommost layer. Furthermore, the engine of the three-dimensional object manufacturing apparatus 30 moves the ultraviolet ray irradiator 33 by the carriage 35 and irradiates the liquid film with ultraviolet rays to harden the liquid film, thereby forming the second layer from the bottom side on the bottommost layer. The engine of the three-dimensional object manufacturing device 30 uses the input two-dimensional data in order from the data closest to the bottom side, and repeats the formation and hardening of the liquid film to stack layers in the same manner as described above. The number of repetitions varies depending on the number of input two-dimensional image data, or the height and shape of the three-dimensional model. When modeling using all the two-dimensional image data is completed, a model of the model part supported by the support part is obtained.

[0048] The object molded by the three-dimensional object manufacturing apparatus 30 has a model portion and a support portion. The support portion is removed from the object after molding. There are two methods for removing the support portion: physical removal and chemical removal. In physical removal, the support portion is removed by applying a mechanical force. On the other hand, in chemical removal, the support portion is removed by immersing the object in a solvent and disintegrating it. There are no particular limitations on the method for removing the support portion, but since physical removal may damage the object, chemical removal is more preferable. Furthermore, in consideration of costs, the method of removing the support portion by immersing the object in water is more preferable. When the method of removing the support portion by immersing the object in water is adopted, a hardened product of the support portion forming material that is water disintegratable is selected.

[0049] <Containment Container> The storage container means a container in which the active energy ray curable composition for inkjet is stored. The container in which the active energy ray curable composition for inkjet is stored can be used as a cartridge or a bottle, and this eliminates the need to directly touch the active energy ray curable composition for inkjet during transportation, replacement, and other operations, and can prevent the hands, fingers, and clothes from getting dirty. In addition, it is possible to prevent foreign matter such as dust from being mixed into the active energy ray curable composition for inkjet. In addition, the shape, size, material, and the like of the container itself may be suitable for the application and usage, and are not particularly limited, but it is preferable that the material is a light-shielding material that does not transmit light, or the container is covered with a light-shielding sheet or the like.

[0050] A three-dimensional object manufactured by the method for manufacturing a three-dimensional object of the present invention and the apparatus for manufacturing a three-dimensional object of the present invention is biocompatible and has a high elastic modulus, high strength, and high hardness as described below, and can therefore be suitably used, for example, as dental materials such as inlays, crowns, dentures, artificial teeth, and implants.

[0051] The Vickers hardness of the three-dimensional object is preferably 23 or more, more preferably 26 or more, and even more preferably 35 or more. The Vickers hardness can be measured, for example, based on the procedure of JIS Z2244.

[0052] The bending strength of the three-dimensional object is preferably 80 MPa or more, more preferably 100 MPa or more, and even more preferably 120 MPa or more. The bending strength was measured using a universal testing machine (Autograph, Model AG-I, Shimadzu Corporation) with a 1 kN load cell and a three-point bending jig. The distance between the supports was set to 24 mm, and the stress when the load point was displaced at a rate of 1 mm / min was plotted against the amount of strain, and the stress at the breaking point was taken as the maximum stress. EXAMPLES

[0053] Examples of the present invention will be described below, but the present invention is not limited to these examples.

[0054] Example 1 56.0 parts by mass of ethoxylated bisphenol A dimethacrylate (trade name: BPE-100 / D-2.6E, manufactured by Shin-Nakamura Chemical Co., Ltd.), 24.0 parts by mass of triethylene glycol dimethacrylate (trade name: NK Ester 3G, manufactured by Shin-Nakamura Chemical Co., Ltd.), and 20.0 parts by mass of inorganic filler (silica, trade name: Admafine 3SM-C11, volume average primary particle diameter = 300 nm, manufactured by Admatechs Co., Ltd.) were mixed. Next, 4.0 parts by mass of diphenyl (2,4,6-trimethylbenzoyl) phosphine oxide (trade name: Omunirad TPO H, manufactured by BASF) was added as a photopolymerization initiator and mixed. Then, the mixture was filtered through a filter (trade name: CCP-FX-C1B, manufactured by Advantec Co., Ltd., average pore size: 3 μm) to obtain an active energy ray curable composition for inkjet of Example 1.

[0055] (Examples 2 to 10 and Comparative Examples 1 to 5) In Example 1, except that the compositions and contents were changed to those shown in Tables 1 to 3, the same procedure as in Example 1 was carried out to obtain active energy ray-curable compositions for inkjet of Examples 2 to 10 and Comparative Examples 1 to 5.

[0056] Next, the properties of each of the obtained active energy ray-curable compositions for inkjet printing were evaluated as follows. The results are shown in Tables 1 to 3.

[0057] <Method of measuring viscosity> Each active energy ray-curable composition for inkjet was measured using a cone-plate type rotational viscometer (VISCOMETER TVE-22L, manufactured by Toki Sangyo Co., Ltd.) and evaluated according to the following criteria. The temperature inside the measurement container was fixed at 25°C using a high-temperature circulating bath, and a cone rotor (1°34' x R24) was used. [Evaluation Criteria] A: Viscosity at 25°C is 300 mPa s or less B: Viscosity at 25°C is greater than 300 mPa·s and less than 600 mPa·s C: Viscosity at 25℃ is more than 600mPa·s

[0058] <Dispersibility> Each active energy ray-curable composition for inkjet was diluted 100 times with the monomer used after dispersion of the inorganic filler, and the presence or absence of settling of particles at the bottom of the glass bottle was visually confirmed, and dispersibility was evaluated based on the following criteria. [Evaluation Criteria] A: No settling for 3 days or more B: No settling for 1 day or more but less than 3 days C: Settling occurred within 1 day

[0059] <3D modeling> Each active energy ray curable composition for inkjet was filled in a tank connected to an inkjet head (MH2810, manufactured by Ricoh Co., Ltd.) of a three-dimensional object manufacturing device, and each active energy ray curable composition for inkjet was discharged from the inkjet head onto a substrate. Next, each active energy ray curable composition for inkjet discharged onto the substrate was irradiated with an ultraviolet ray irradiator (UniJet E110Z HD, wavelength 385 nm, manufactured by Ushio Inc.) at a light intensity of 300 mJ / cm. 2 The active energy ray-curable compositions for inkjet printing on the substrate were cured by irradiating the active energy ray-curable compositions with the active energy ray-curable compositions for inkjet printing on the substrate. By repeating this series of steps, a three-dimensional object having a rectangular shape of 10 mm×40 mm×1 mm was fabricated.

[0060] <Vickers hardness (HV 0.2)> The Vickers hardness of each of the obtained three-dimensional objects was measured according to the procedure of JIS Z2244 and evaluated according to the following criteria, where C or higher is the level suitable for practical use. [Evaluation Criteria] A: Vickers hardness 35 or more B: Vickers hardness is 26 or more and less than 35 C: Vickers hardness is 22 or more and less than 26 D: Vickers hardness less than 22

[0061] <Method of measuring bending strength> The bending strength of each of the three-dimensional objects obtained was measured as follows. A universal testing machine (Autograph, Model AG-I, manufactured by Shimadzu Corporation) was used to measure the bending strength of each three-dimensional object, along with a 1 kN load cell and a three-point bending jig. The distance between the supports was set to 24 mm, and the stress when the load point was displaced at a speed of 1 mm / min was plotted against the amount of strain, with the stress at the breaking point being the maximum stress. Grades B and above are suitable for practical use. [Evaluation Criteria] A: Bending strength is 120MPa or more B: Bending strength is 100MPa or more and less than 120MPa C: Bending strength is 80MPa or more and less than 100MPa D: Bending strength is less than 80 MPa

[0062] [Table 1]

[0063] [Table 2]

[0064] [Table 3]

[0065] Details of each component in Tables 1 to 3 are as follows. [Monomer component] -Bisphenol methacrylate- *BPE-100 / D-2.6E: Ethoxylated bisphenol A dimethacrylate, manufactured by Shin-Nakamura Chemical Co., Ltd., viscosity at 25°C 1,050 mPa·s *BPE-500: Ethoxylated bisphenol A dimethacrylate, manufactured by Shin-Nakamura Chemical Co., Ltd., viscosity 450 mPa·s at 25°C

[0066] -Low viscosity monomer- *NK Ester 1G: Monoethylene glycol dimethacrylate, manufactured by Shin-Nakamura Chemical Co., Ltd., viscosity 3 mPa s at 25°C *NK Ester 2G: Diethylene glycol dimethacrylate, manufactured by Shin-Nakamura Chemical Co., Ltd., viscosity 5 mPa s at 25°C *NK Ester 3G: Triethylene glycol dimethacrylate, manufactured by Shin-Nakamura Chemical Co., Ltd., viscosity 9 mPa s at 25°C

[0067] -Other methacrylates- *EDMA: Erythritol dimethacrylate [1,4-bis(methacryloyloxy)-2,3-butanediol], manufactured by Tokyo Chemical Industry Co., Ltd., viscosity at 25°C: 480 mPa·s

[0068] -Acrylate- *A-BPE-4: Ethoxylated bisphenol A diacrylate, manufactured by Shin-Nakamura Chemical Co., Ltd., viscosity at 25°C: 1,100 mPa·s *APG-200: Tripropylene glycol diacrylate, manufactured by Shin-Nakamura Chemical Co., Ltd., viscosity 12 mPa·s at 25°C

[0069] [Inorganic filler] * ADMAFINE 3SM-C11: Silica, volume average primary particle size = 300 nm, manufactured by ADMATECHS Co., Ltd., spherical, methacrylate treatment with silane coupling agent *Admanano YA-100CSM2: Silica, volume average primary particle size = 100 nm, manufactured by Admatechs Co., Ltd., spherical, methacrylate treatment with silane coupling agent *Admanano YA-10CSM1: Silica, volume average primary particle size = 10 nm, manufactured by Admatechs Co., Ltd., spherical, methacrylate treatment with silane coupling agent * ADMAFINE S2500-SMJ: Silica, volume average primary particle size = 500 nm, manufactured by ADMATECHS Co., Ltd., spherical, methacrylate treatment with silane coupling agent *PT-401L: Titania, volume average primary particle size = 130 nm, manufactured by Ishihara Sangyo Kaisha, Ltd., spherical, surface untreated * ADMAFINE AO-502: Alumina, volume average primary particle size = 300 nm, manufactured by ADMATECHS Co., Ltd., spherical, methacrylate treatment with silane coupling agent

[0070] The volume average primary particle diameter of the inorganic filler is a value measured by a dynamic light scattering method using an ELS-Z instrument manufactured by Otsuka Electronics Co., Ltd., and was measured using an inorganic filler dispersion diluted 100 times with 2-methoxy-1-methylethyl acetate.

[0071] -Other fillers- *Silane-treated barium glass: average particle size = 2,400 nm. Barium glass (manufactured by Estec Co., Ltd., product code "Raysorb E-3000") was pulverized in a ball mill to obtain barium glass powder. The average particle size of the obtained barium glass powder was measured using a laser diffraction particle size distribution measuring device (manufactured by Shimadzu Corporation, model "SALD-2100") and found to be 2.4 μm. The barium glass powder was surface-treated with 3 parts by mass of 3-methacryloyloxypropyltrimethoxysilane per 100 parts by mass to obtain silane-treated barium glass powder.

[0072] -Polymerization initiator- *Camphorquinone: manufactured by Tokyo Chemical Industry Co., Ltd. *PDE: Ethyl-4-dimethylaminobenzoate, polymerization accelerator, manufactured by Tokyo Chemical Industry Co., Ltd. *Omirad TPO H: Diphenyl(2,4,6-trimethylbenzoyl)phosphine oxide, manufactured by BASF

[0073] The results in Tables 1 to 3 show that, compared to Comparative Examples 1 to 5, Examples 1 to 10 were capable of forming three-dimensional objects having good inkjet ejection properties while also having high elasticity, high strength, and high hardness. The results of Example 6 show that even though the inorganic filler content is 60% by mass, the viscosity at 25°C is low at 240 mPa s, making it possible to eject the ink from an inkjet printer. It also shows that the ink has excellent mechanical properties, such as a Vickers hardness of 42 and a flexural modulus of 110 MPa. In contrast, the results of Comparative Example 1 show that when diacrylate is used instead of dimethacrylate as the low-viscosity monomer, the Vickers hardness decreases. From the results of Comparative Example 2, it was found that when a non-bisphenol type methacrylate was used instead of the bisphenol type methacrylate, the Vickers hardness decreased. From the results of Comparative Example 3, when a large amount of inorganic filler having a large particle size such as dental grade was added, the viscosity became too high and bubbles could not be removed, so that it became impossible to measure the Vickers hardness, bending strength, and dispersibility, and an active energy ray-curable composition for inkjet was not obtained. From the results of Comparative Example 4, it was found that when ethoxylated bisphenol A diacrylate and diacrylate were used as monomer components, the Vickers hardness and bending strength decreased. From the results of Comparative Example 5, it was found that when ethoxylated bisphenol A diacrylate was used instead of ethoxylated bisphenol A dimethacrylate, the Vickers hardness and bending strength decreased.

[0074] For example, aspects of the present invention are as follows. <1> The active energy ray-curable composition for inkjet printing is characterized by comprising a monomer component including a bisphenol-type methacrylate and a low-viscosity monomer, and an inorganic filler. <2> The mass ratio (A:B) of the content (A) of the monomer component to the content (B) of the inorganic filler is 90:10 to 40:60. <1> 2. The active energy ray-curable composition for inkjet recording according to claim 1, <3> The low-viscosity monomer is at least one selected from ethylene glycol dimethacrylate (n=1), diethylene glycol dimethacrylate (n=2), and triethylene glycol dimethacrylate (n=3) represented by the following general formula (1): <1> from <2> 10. The active energy ray-curable composition for inkjet according to claim 9, [ka] <4> The bisphenol methacrylate is an ethoxylated bisphenol A dimethacrylate having a viscosity of 2,000 mPa·s or less at 25°C. <1> from <3> 10. The active energy ray-curable composition for inkjet according to claim 9, <5> The mass ratio (a1:a2) of the bisphenol methacrylate (a1) to the low-viscosity monomer (a2) is 70:30 to 30:70. <1> from <4> 10. The active energy ray-curable composition for inkjet according to claim 9, <6> The inorganic filler is a spherical particle having a volume average primary particle diameter of 10 nm or more and 500 nm or less. <1> from <5> 10. The active energy ray-curable composition for inkjet according to claim 9, <7> The inorganic filler is at least one selected from the group consisting of silica, alumina, titania and zirconia. <1> from <6> 10. The active energy ray-curable composition for inkjet according to claim 9, <8> The inorganic filler is surface-modified with a silane coupling agent. <1> from <7> 10. The active energy ray-curable composition for inkjet according to claim 9, <9> The curing time required for the storage modulus of the monomer component to reach 1 MPa as measured by a photorheometer with a wavelength of 385 nm is within 10 seconds. <1> from <8> 10. The active energy ray-curable composition for inkjet according to claim 9, <10> The above <1> from <9> a discharge step of discharging the active energy ray-curable composition for inkjet according to any one of the above items; a curing step of curing the discharged active energy ray-curable composition for inkjet by irradiating the composition with active energy rays; The present invention relates to a method for producing a three-dimensional object, comprising the steps of: <11> The above <1> from <9> a discharge means for discharging the active energy ray-curable composition for inkjet according to any one of the above items; a curing means for curing the discharged active energy ray-curable composition for inkjet printing by irradiating the composition with active energy rays; The present invention relates to a manufacturing apparatus for a three-dimensional object, comprising:

[0075] The above <1> from <9> The active energy ray-curable composition for inkjet according to any one of the preceding claims. <10> The method for producing a three-dimensional object according to the present invention <11> According to the apparatus for manufacturing a three-dimensional object described above, the conventional problems can be solved and the object of the present invention can be achieved. [Prior art documents] [Patent documents]

[0076] [Patent Document 1] JP 2017-160405 A

Claims

1. The composition contains a monomer component including a low-viscosity monomer that is a bisphenol-type methacrylate and a methacrylate having a viscosity of 100 mPa·s or less at 25°C, and an inorganic filler; a mass ratio (A:B) of the monomer component (A) to the inorganic filler (B) is 80:20 to 40:60; An active energy ray-curable composition for inkjet recording, characterized in that the viscosity in an environment of 25°C is 600 mPa·s or less.

2. 2. The active energy ray-curable composition for inkjet according to claim 1, wherein the low-viscosity monomer is at least one selected from ethylene glycol dimethacrylate (n = 1), diethylene glycol dimethacrylate (n = 2), and triethylene glycol dimethacrylate (n = 3), each represented by the following general formula (1): 【Chemistry 1】

3. 3. The active energy ray-curable composition for inkjet according to claim 1, wherein the bisphenol methacrylate is an ethoxylated bisphenol A dimethacrylate having a viscosity of 2,000 mPa·s or less at 25°C.

4. 4. The active energy ray-curable composition for inkjet according to claim 1, wherein a mass ratio (a1:a2) of the bisphenol methacrylate (a1) to the low-viscosity monomer (a2) is 70:30 to 30:

70.

5. The active energy ray-curable composition for inkjet according to claim 1 , wherein the inorganic filler is a spherical particle having a volume average primary particle diameter of 10 nm or more and 500 nm or less.

6. The active energy ray-curable composition for inkjet according to claim 1 , wherein the inorganic filler is at least one selected from the group consisting of silica, alumina, titania, and zirconia.

7. The active energy ray-curable composition for inkjet according to claim 1 , wherein the inorganic filler is surface-modified with a silane coupling agent.

8. 8. The active energy ray-curable composition for inkjet according to claim 1, wherein a curing time required for the storage modulus of the monomer component to reach 1 MPa as measured with a photorheometer at a wavelength of 385 nm is within 10 seconds.

9. A step of discharging the active energy ray-curable composition for inkjet according to claim 1 ; a curing step of curing the discharged active energy ray-curable composition for inkjet by irradiating the composition with active energy rays; A method for producing a three-dimensional object, comprising:

10. A discharge means for discharging the active energy ray-curable composition for inkjet according to any one of claims 1 to 8; a curing means for curing the discharged active energy ray-curable composition for inkjet printing by irradiating the composition with active energy rays; An apparatus for manufacturing a three-dimensional object, comprising:

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