Three-dimensional stereolithographic curable composition, method for producing same, and method for producing three-dimensional stereolithographic article

Abstract

Provided are a three-dimensional stereolithographic curable composition and a method for producing the same, the three-dimensional stereolithographic curable composition comprising: 100 parts by mass of a radically polymerizable monomer (A) that is liquid at 25ºC; 50-250 parts by mass of an inorganic filler (B); 0.05-5.0 parts by mass of a photopolymerization initiator (C) that absorbs activation light and generates radicals; 0.01-2.5 parts by mass of an activation light absorber (D) that absorbs activation light; 0.01-5.0 parts by mass of a polymerization inhibitor (E); and 0.3-10 parts by mass of a hyperbranched polymer (F) that is soluble in the radically polymerizable monomer (A). Moreover, provided is a method for producing a three-dimensional stereolithographic article using said three-dimensional stereolithographic curable composition.

Description

Curable composition for three-dimensional optical modeling, method for producing the same, and method for producing three-dimensional optical modeled object

[0001] The present disclosure relates to a curable composition for three-dimensional optical shaping, a method for producing the same, and a method for producing a three-dimensional optically shaped object.

[0002] The technology of forming a three-dimensional object by irradiating a photocurable composition (also called a photocurable resin or a photocurable resin composition) containing a polymerizable monomer and a photopolymerization initiator with light that activates the photopolymerization initiator (activating light) to harden the composition is known as a stereolithography method. There are several stereolithography methods, and among them, the liquid vat photopolymerization method is widely used because the equipment is relatively inexpensive and it can produce objects with smooth surfaces with high precision.

[0003] In the liquid vat photopolymerization method, a three-dimensional object is typically obtained as follows. First, the height direction of the three-dimensional object is digitized and ranked from three-dimensional shape data representing the shape of the three-dimensional object, and two-dimensional shape data representing the cross-sectional shape of the three-dimensional object at each ranked height is generated. Next, activating light is applied to a liquid photocurable composition held in a vat at predetermined positions determined based on the two-dimensional shape data, selectively curing the liquid photocurable composition present at those positions to form a modeling layer having the cross-sectional shape. Furthermore, modeling layers having the cross-sectional shapes at each height are sequentially formed and stacked in the ranked order to obtain a laminate having a shape corresponding to the shape of the three-dimensional object. The laminate is then washed with an organic solvent, if necessary, and then subjected to secondary curing to obtain the desired object.

[0004] In the field of dentistry, dental restorations such as dentures and crown prostheses must be manufactured with high dimensional accuracy in a unique shape that is tailored to the condition of the oral cavity of each individual patient. For this reason, the manufacture of dental restorations by stereolithography using a liquid vat photopolymerization method has been considered, based on CAD (Computer Aided Design) data designed using digital data obtained by intraoral scanning or the like.

[0005] Dental prostheses used in the oral cavity require not only high dimensional (shape) accuracy as described above, but also high mechanical strength sufficient to withstand the loads imposed by mastication. In this regard, when an inorganic filler is incorporated into a photocurable composition, polymerization shrinkage, which is one of the causes of reduced accuracy, can be reduced, and the mechanical strength and surface hardness of the cured product can be improved. For this reason, liquid vat photopolymerization using a photocurable composition containing an inorganic filler is considered suitable for stereolithography of dental prostheses, and a curable composition for three-dimensional stereolithography containing such an inorganic filler has also been proposed.

[0006] For example, Patent Document 1 discloses a composition for optical three-dimensional modeling that exhibits excellent modeling accuracy, mechanical properties, and transparency, and is particularly suitable for dental materials. The composition contains a polymerizable monomer (a), ultraviolet-absorbing inorganic particles (b), and a photopolymerization initiator (c). Patent Document 2 discloses a resin composition capable of producing a cured product (three-dimensional object) with excellent design, the composition containing a light-transmitting resin and two or more types of light-transmitting particles with different refractive indices and Abbe numbers. Patent Document 3 also discloses a resin composition for optical modeling that can produce a three-dimensional object with high strength, high elasticity, and excellent abrasion resistance. The composition contains a urethane-modified (meth)acrylic compound (a), a (meth)acrylamide compound (b), a photopolymerization initiator (c), and spherical inorganic particles (d) having an average particle size of 0.75 to 10 μm, with the spherical inorganic particles (d) contained in an amount of 50 to 400 parts by mass per 100 parts by mass of the total amount of polymerizable monomers.

[0007] Furthermore, Patent Document 4 discloses a composition having low viscosity and low shrinkage, suitable for producing artificial teeth and denture bases by three-dimensional printing, which is "a composition characterized by comprising a photocurable viscous mixture containing, relative to the total weight of the composition, 0 to 50% by weight of a solution in which polymerized poly(methyl methacrylate) is dissolved in a methyl methacrylate monomer solvent, 5 to 20% by weight of at least one polyfunctional aliphatic (meth)acrylate, 5 to 40% by weight of at least one aliphatic urethane (meth)acrylate oligomer, 25 to 65% by weight of at least one difunctional bisphenol-A dimethacrylate, 0.1 to 5% by weight of at least one photoinitiator, 0.05 to 2% by weight of at least one light stabilizer, and 0.1 to 3% by weight of a color pigment."

[0008] International Publication No. 2018 / 074380 JP 2020-180171 A JP 2022-41276 A JP 2016-525150 A Japanese Patent No. 5882921 A

[0009] Patent Documents 1 to 3 use compositions containing polymerizable monomers and inorganic fillers, which allows for the production of molded objects with excellent mechanical strength, elastic modulus, and abrasion resistance. However, the optical 3D modeling composition described in Patent Document 1 has low fluidity, which may limit the shape of the object that can be manufactured. Furthermore, the resin composition described in Patent Document 2 may experience sedimentation of the translucent particles (e.g., glass filler) contained in the composition when left stationary for a long period of time. Furthermore, it has been revealed that the stereolithography resin composition described in Patent Document 3 often causes fine cracks on the surface of the molded object that are difficult to detect visually (see FIG. 3). When a molded object having such fine cracks is used as a dental prosthesis, this can be problematic because it may become the starting point for fracture of the dental prosthesis in the oral cavity.

[0010] Furthermore, the composition described in Patent Document 4 incorporates polymerized poly(methyl methacrylate) to reduce the amount of shrinkage during stereolithography and suppress cracks on the surface of the model. However, when such a polymer component is mixed into the composition, the strength of the model tends to decrease. Furthermore, since the viscosity of the composition tends to increase, when an inorganic filler is incorporated to increase the strength, the viscosity increases significantly, making the composition difficult to handle.

[0011] Therefore, an object of the present disclosure is to provide a technology that enables the production of high-strength three-dimensional optically shaped objects by liquid vat photopolymerization using a curable composition for three-dimensional optically shaped objects containing a certain amount of inorganic filler to increase strength, without generating cracks on the surface.

[0012] Specific means for solving the above problems include the following embodiments: <1> A curable composition for three-dimensional stereolithography, comprising: 100 parts by mass of a radically polymerizable monomer (A) that is liquid at 25°C; 50 to 250 parts by mass of an inorganic filler (B); 0.05 to 5.0 parts by mass of a photopolymerization initiator (C) that absorbs activating light and generates radicals; 0.01 to 2.5 parts by mass of an activating light absorber (D) that absorbs activating light; 0.01 to 5.0 parts by mass of a polymerization inhibitor (E); and 0.3 to 10 parts by mass of a hyperbranched polymer (F) that is soluble in the radically polymerizable monomer (A).

[0013] <2> The hyperbranched polymer (F) is represented by the following formula (I): (Wherein, A is independently selected from C and R １ and a single bond connecting the two, >C═O, —O—, —COO—, or —COO—CH ２ - indicates R １ represents a divalent saturated aliphatic hydrocarbon group or a divalent aromatic hydrocarbon group, and R ２ each independently represents a hydrogen atom or a methyl group, and a first unit structure having four bonds represented by the following formula (IIA) and the following formula (IIB): (In the formula, R ３ , R ４ , and R ５each independently represents a hydrogen atom, an alkyl group having 1 to 5 carbon atoms constituting the main chain, an alkoxycarbonyl group having 2 to 6 carbon atoms constituting the main chain, an aryl group, or a cyano group; R ６ represents an alkylene group having 4 to 10 carbon atoms constituting the main chain.) and a second unit structure which is at least one of two unit structures represented by the following formula (1).

[0014] <3> The curable composition for three-dimensional optical fabrication according to <1> or <2>, wherein the content of the hyperbranched polymer (F) is 2 to 10 parts by mass per 100 parts by mass of the content of the radical polymerizable monomer (A).

[0015] <4> 90% by mass or more of the radical polymerizable monomer (A) is composed of a polyfunctional (meth)acrylate radical polymerizable monomer (a) having two or more (meth)acryloyl groups in the molecule and having 5 to 25 atoms constituting the main chain of a divalent group intervening between the two or more (meth)acryloyl groups in the molecule, and the polyfunctional (meth)acrylate radical polymerizable monomer (a) is composed of a polyfunctional (meth)acrylate radical polymerizable monomer (a1) having at least one bond selected from the group consisting of a urethane bond, a urea bond, and an isocyanurate ring, and another polyfunctional (meth)acrylate radical polymerizable monomer (a2), <3> The curable composition for three-dimensional optical modeling according to any one of <1> to <3>, wherein 40 to 90 mass % of the radical polymerizable monomer (A) is the polyfunctional (meth)acrylate radical polymerizable monomer (a1), and 10 to 60 mass % of the radical polymerizable monomer (a2).

[0016] <5> The curable composition for three-dimensional stereolithography according to any one of <1> to <4>, further comprising 0.005 to 1.0 parts by mass of a chain transfer agent (G).

[0017] <6> The curable composition for three-dimensional stereolithography according to any one of <1> to <5>, which is used as the liquid photocurable composition in three-dimensional stereolithography, in which the height direction of the three-dimensional object is digitized and ranked from three-dimensional shape data representing the shape of the three-dimensional object, and two-dimensional shape data representing the cross-sectional shape of the three-dimensional object at each ranked height is generated, and a liquid vat photopolymerization method is used in which predetermined positions of a liquid photocurable resin composition held in a vat are irradiated with ultraviolet or visible light activating light to selectively harden the liquid photocurable resin composition present at the predetermined positions, and modeling layers having shapes corresponding to the two-dimensional shapes at each height are sequentially formed and stacked in the ranked order based on the two-dimensional shape data, thereby obtaining a laminate having a shape corresponding to the shape of the three-dimensional object.

[0018] <7> A method for producing the curable composition for three-dimensional optical shaping according to any one of <1> to <6>, comprising mixing the radical polymerizable monomer (A), the photopolymerization initiator (C), the activated light absorber (D), the polymerization inhibitor (E), and the hyperbranched polymer (F) to prepare a liquid composition in which at least a portion of the hyperbranched polymer is dissolved, and then mixing the liquid composition with the inorganic filler (B).

[0019] <8> The method for producing a curable composition for three-dimensional optical modeling according to <7>, wherein, when preparing the liquid composition, a hyperbranched polymer powder having a hydrodynamic average diameter in tetrahydrofuran measured by dynamic light scattering of 2 to 40 nm is mixed.

[0020] <9> A method for producing a three-dimensional optically shaped object, comprising: digitizing and ranking the height direction of the three-dimensional object from three-dimensional shape data representing the shape of the three-dimensional object, generating two-dimensional shape data representing the cross-sectional shape of the three-dimensional object at each ranked height; and using a liquid vat photopolymerization method in which predetermined positions of a liquid photocurable resin composition held in a vat are irradiated with ultraviolet or visible light activating light to selectively cure the liquid photocurable resin composition present at the predetermined positions, to sequentially form and stack modeling layers having shapes corresponding to the two-dimensional shapes at each height in the order of the ranking based on the two-dimensional shape data, thereby obtaining a laminate having a shape corresponding to the shape of the three-dimensional object; wherein the method uses the curable composition for three-dimensional optical shaping according to any one of <1> to <6> as the liquid photocurable resin composition.

[0021] The curable composition for three-dimensional optical modeling according to the present disclosure makes it possible to produce a three-dimensional optically modeled object that has excellent mechanical strength and good modeling accuracy, while suppressing a decrease in fluidity and sedimentation of inorganic fillers and preventing cracks from occurring on the surface of the cured object.

[0022] 1 is a diagram showing the surface of a three-dimensional stereolithography object obtained in Example 1, observed under an optical microscope (magnification: 50x); FIG. 2 is a diagram showing the surface of a three-dimensional stereolithography object obtained in Comparative Example 1, observed under an optical microscope (magnification: 50x); FIG. 3 is a diagram showing the surface of a three-dimensional stereolithography object obtained in Comparative Example 5, observed under an optical microscope (magnification: 50x).

[0023] As described above, photocurable compositions containing a certain amount of inorganic filler to improve the mechanical strength and surface hardness of the cured product can suffer from problems such as reduced fluidity and particle settling during storage. Furthermore, when a model is produced by a liquid tank photopolymerization method using the stereolithography resin composition described in Patent Document 3, fine cracks that are difficult to detect visually often occur on the surface of the model (although this is not recognized in Patent Document 3).

[0024] Although the reason why cracks occur on the surface of a molded object is unclear, the inventors have confirmed that cracks occur when, after obtaining a laminate using a stereolithography device, the uncured curable composition adhering to the surface of the laminate is washed with an organic solvent. The bonded portions of the modeling layers in the laminate have a lower polymerization rate than other portions. Furthermore, when an inorganic filler is included, the polymerization rate is lower in portions where the laser light irradiation intensity is weakened due to light scattering than in other portions. When the organic solvent penetrates into such regions of low polymerization rate during washing, the regions swell, causing the intermolecular spacing of the polymer chains constituting the molded object to increase, temporarily reducing the strength. It is believed that this occurs when the internal stress remaining in the molded object during the molding process destroys the portions with reduced strength, resulting in the generation of cracks in those regions.

[0025] It is unclear why cracks on the surface of the shaped object were not recognized in Patent Document 3, but the inventors conducted a follow-up experiment and observed cracks. From this, it is believed that the occurrence of cracks was probably overlooked in Patent Document 3.

[0026] In the curable composition for three-dimensional optical modeling disclosed herein, in order to increase the strength of the modeled object while avoiding problems such as reduced fluidity and particle settling during storage, and to suppress the occurrence of cracks, the amount of inorganic filler blended is 50 to 250 parts by mass per 100 parts by mass of polymerizable monomer, and a hyperbranched polymer that is soluble in the polymerizable monomer is blended.

[0027] The reason why the incorporation of a specific amount of hyperbranched polymer suppresses cracking is unclear, but is speculated as follows. Specifically, hyperbranched polymers have a structural characteristic in which branching points exist within the repeating unit and the molecular chains extend three-dimensionally (in a dendritic pattern). Therefore, it is believed that the incorporation of hyperbranched polymers protects the surface of the laminate while retaining the polymerizable monomers inside, and prevents swelling due to organic solvents during cleaning. It is also believed that the incorporation of hyperbranched polymers can alleviate internal stresses that occur within the laminate during curing.

[0028] It is known that dental curable compositions, such as dental composite resins, contain hyperbranched polymers to suppress polymerization shrinkage during dental cavity restoration (see Patent Document 5). However, such dental curable compositions have a relatively high polymerization shrinkage rate of approximately 2%, even when the inorganic filler content is as high as 270 parts by mass per 100 parts by mass of polymerizable monomer. Furthermore, in three-dimensional stereolithography using liquid vat photopolymerization, polymerization occurs in the presence of unpolymerized material in the surrounding area, so polymerization shrinkage is unlikely to immediately lead to cracking. Therefore, the above technology does not suggest the effects of the present invention.

[0029] Furthermore, with regard to the aggregation and sedimentation of inorganic fillers during storage, it is believed that in the curable composition for three-dimensional photopolymerization disclosed herein, the presence of minute hyperbranched polymers that are sufficiently dissolved and uniformly dispersed prevents the inorganic fillers from aggregating with each other and makes them less likely to sediment.

[0030] Furthermore, hyperbranched polymers exhibit little intermolecular entanglement, exhibit particulate behavior, and are finely dispersed in the composition, making it difficult to increase viscosity. Furthermore, the polymerizable monomers held in the hyperbranched polymer ultimately harden, making it difficult to reduce the strength of the resulting three-dimensional stereolithography object. Furthermore, when a polymer other than the hyperbranched polymer, such as poly(meth)acrylate, is blended into the composition, not only does the viscosity of the composition increase, reducing its fluidity, but the strength of the resulting three-dimensional stereolithography object also tends to decrease.

[0031] The following describes the presently disclosed curable composition for three-dimensional stereolithography (hereinafter also simply referred to as "curable composition for stereolithography"), its manufacturing method, and a manufacturing method for a three-dimensional stereolithography object. Unless otherwise specified, the expression "x to y" using the numerical values ​​x and y means "x or more and y or less." In such expressions, when a unit is assigned only to the numerical value y, the unit also applies to the numerical value x. Furthermore, in this specification, the term "(meth)acryloyl" refers to both "acryloyl" and "methacryloyl." Similarly, the term "(meth)acrylate" refers to both "acrylate" and "methacrylate."

[0032] <Curable Composition for Stereolithography> The curable composition for stereolithography disclosed herein is a curable composition used as a liquid photocurable composition when producing a three-dimensional stereolithography object by a liquid vat photopolymerization method using activating light containing light of a specific wavelength λ (nm) in the ultraviolet or visible light region, i.e., a curable composition for three-dimensional stereolithography by a liquid vat photopolymerization method.

[0033] Here, the liquid vat photopolymerization method refers to a process that includes the steps of: digitizing and ranking the height direction of a three-dimensional object from three-dimensional shape data representing the shape of the three-dimensional object; generating two-dimensional shape data representing the cross-sectional shape of the three-dimensional object at each ranked height; irradiating a liquid photocurable composition held in a vat with activating light at a predetermined position determined in advance based on the two-dimensional shape data, thereby selectively (primarily) curing the liquid photocurable composition present at that position to form a modeling layer having the cross-sectional shape; and sequentially forming and stacking modeling layers having the cross-sectional shapes at each height in accordance with the ranking order to obtain a laminate having a shape corresponding to the shape of the three-dimensional object (hereinafter also referred to as the "molding process"). If necessary, a cleaning process using an organic solvent (hereinafter also referred to as the "cleaning process") or a secondary curing process (hereinafter also referred to as the "secondary curing process") is performed to obtain a three-dimensional photo-printed object having a shape corresponding to the shape of the three-dimensional object.

[0034] The curable composition for stereolithography disclosed herein is characterized by containing 100 parts by mass of a radically polymerizable monomer (A) that is liquid at 25°C, 50 to 250 parts by mass of an inorganic filler (B), 0.05 to 5.0 parts by mass of a photopolymerization initiator (C) that absorbs activating light and generates radicals, 0.01 to 2.5 parts by mass of an activating light absorber (D) that absorbs activating light, 0.01 to 5.0 parts by mass of a polymerization inhibitor (E), and 0.3 to 10 parts by mass of a hyperbranched polymer (F) that is soluble in the radically polymerizable monomer (A).

[0035] By including the radical polymerizable monomer (A), the inorganic filler (B), and the hyperbranched polymer (F) in the above-mentioned ratio, it is possible to increase the strength and surface hardness of the three-dimensional optically shaped object. It is also possible to suppress an increase in the viscosity of the composition and the risk of inorganic filler particles settling during storage. Furthermore, it is possible to prevent the occurrence of fine cracks on the surface of the three-dimensional optically shaped object that are difficult to detect visually.

[0036] Each component contained in the curable composition for stereolithography according to the present disclosure will be described below. Each of the following components may be used alone or in combination of two or more.

[0037] [Radical Polymerizable Monomer (A)] As the radical polymerizable monomer (A), any radically polymerizable monomer that is liquid at 25° C. can be used without any particular limitation. Among radical polymerizable monomers, it is preferable to use a (meth)acrylate radical polymerizable monomer because it has a fast curing rate and the strength of the resulting three-dimensional stereolithographic object is excellent.

[0038] Furthermore, in terms of achieving excellent strength of the resulting three-dimensional optically shaped object, it is preferable that 90% by mass or more (preferably 95% by mass or more, more preferably 100% by mass) of the radical polymerizable monomer (A) be a polyfunctional (meth)acrylate radical polymerizable monomer (a) having two or more (meth)acryloyl groups in the molecule, and having 5 to 25 atoms constituting the main chain of the divalent group interposed between the two or more (meth)acryloyl groups present in the molecule. Here, "the number of atoms constituting the main chain of the divalent group is 5 to 25" means that the number of atoms constituting the main chain of all "divalent groups" interposed between two adjacent (meth)acryloyl groups in the molecule is 5 to 25. For example, if the number of (meth)acryloyl groups present in the molecule is 3, there will be two "divalent groups," and for each of these two "divalent groups," the number of atoms constituting the main chain is 5 to 25. When the "divalent group" contains a ring structure in the main chain, specifically, when the ring structure is introduced into the main chain by bonds present on each of two ring-constituting atoms, the path between the two ring-constituting atoms that has fewer ring-constituting atoms is counted as part of the main chain.

[0039] When the radical polymerizable monomer (A) containing 90 mass % or more of such a polyfunctional (meth)acrylate radical polymerizable monomer (a) is used, the chain transfer of radicals caused by further blending a chain transfer agent (G) described later can reduce the above-mentioned state in which the polymerization rate is partially low, and furthermore, the occurrence of cracks can be suppressed.

[0040] Furthermore, the polyfunctional (meth)acrylate radical polymerizable monomer (a) comprises a polyfunctional (meth)acrylate radical polymerizable monomer (a1) having at least one selected from the group consisting of a urethane bond (—NH—CO—O—), a urea bond (—NH—CO—NH—), and an isocyanurate ring, and another polyfunctional (meth)acrylate radical polymerizable monomer (a2), and it is preferred that 40 to 90 mass% of the radical polymerizable monomer (A) is the polyfunctional (meth)acrylate radical polymerizable monomer (a1) and 10 to 60 mass% is the polyfunctional (meth)acrylate radical polymerizable monomer (a2). The content of the polyfunctional (meth)acrylate radical polymerizable monomer (a1) in the radical polymerizable monomer (A) is preferably 45 to 85 mass%, more preferably 48 to 82 mass%. The content of the polyfunctional (meth)acrylate radically polymerizable monomer (a2) in the radically polymerizable monomer (A) is preferably 15 to 55% by mass, more preferably 18 to 52% by mass.

[0041] Examples of compounds that can be suitably used as the polyfunctional (meth)acrylate radically polymerizable monomer (a1) include 1,6-bis(methacryloyloxy-2-ethoxycarbonylamino)-2,2,4-trimethylhexane, 1,6-bis(methacryloyloxy-2-ethoxycarbonylamino)-2,4,4-trimethylhexane, phenyl glycidyl ether-(meth)acrylate hexamethylene diisocyanate urethane prepolymer, pentaerythritol tri(meth)acrylate hexamethylene diisocyanate urethane prepolypolymer, Examples of suitable (meth)acrylates include urethane group-containing (meth)acrylates such as pentaerythritol tri(meth)acrylate isophorone diisocyanate urethane prepolymer and dipentaerythritol penta(meth)acrylate hexamethylene diisocyanate urethane prepolymer; and isocyanurate skeleton-containing (meth)acrylates such as tris(2-methacryloyloxyethyl)isocyanurate, caprolactone-modified tris-(2-acryloxyethyl)isocyanurate. Among these, 1,6-bis(methacryloyloxy-2-ethoxycarbonylamino)-2,2,4-trimethylhexane, 1,6-bis(methacryloyloxy-2-ethoxycarbonylamino)-2,4,4-trimethylhexane, and caprolactone-modified tris-(2-acryloxyethyl)isocyanurate are preferred from the viewpoints of low viscosity and high strength.

[0042] Examples of compounds that can be suitably used as the polyfunctional (meth)acrylate radically polymerizable monomer (a2) include bisphenol A skeleton-containing (meth)acrylates such as 2,2'-bis{4-[3-(meth)acryloyloxy-2-hydroxypropoxy]phenyl}propane, 2,2'-bis[4-(meth)acryloyloxyphenyl]propane, and 2,2'-bis[4-(meth)acryloyloxypolyethoxyphenyl]propane; ethylene glycol-based (meth)acrylates such as triethylene glycol dimethacrylate and ethylene glycol dimethacrylate; aliphatic di(meth)acrylates such as 1,3-propanediol di(meth)acrylate and 1,9-nonanediol dimethacrylate; and trifunctional (meth)acrylates such as trimethylolpropane trimethacrylate. Among these, 2,2'-bis[4-(meth)acryloyloxyphenyl]propane, 2,2'-bis[4-(meth)acryloyloxypolyethoxyphenyl]propane, and triethylene glycol dimethacrylate are preferred from the viewpoint of low viscosity and high strength.

[0043] The radically polymerizable monomer (A) may contain a radically polymerizable monomer other than the polyfunctional (meth)acrylate radically polymerizable monomer (a). Examples of the other radically polymerizable monomer include monofunctional (meth)acrylate radically polymerizable monomers such as hydroxyethyl (meth)acrylate, methyl (meth)acrylate, ethyl (meth)acrylate, isopropyl (meth)acrylate, tetrahydrofurfuryl (meth)acrylate, glycidyl (meth)acrylate, 2-methacryloxyethyl propionate, and acetoacetoxyethyl (meth)acrylate.

[0044] [Inorganic Filler (B)] In order to increase the mechanical strength, such as rigidity, of the resulting three-dimensional stereolithography object and prevent a decrease in the fluidity of the composition, the stereolithography curable composition of the present disclosure contains 50 to 250 parts by mass of inorganic filler (B) per 100 parts by mass of radical polymerizable monomer (A). The inorganic filler (B) is composed of a single type or multiple types of inorganic powder or particles. If the content of inorganic filler (B) is too high, the viscosity of the stereolithography curable composition tends to be too high. On the other hand, if the content of inorganic filler (B) is too low, the mechanical strength of the resulting three-dimensional stereolithography object tends to be insufficient. For this reason, the content of inorganic filler (B) is preferably 100 to 200 parts by mass per 100 parts by mass of radical polymerizable monomer (A).

[0045] Furthermore, from the viewpoint of suppressing an increase in viscosity of the curable composition for stereolithography and suppressing particle sedimentation of the present disclosure, it is preferable that, in the particle size distribution of the inorganic filler (B) measured by a microscopy method using a scanning microscope, 80% or more of all primary particles constituting the inorganic filler (B) have a particle diameter of 0.05 to 5.0 μm. From the viewpoint of further suppressing an increase in viscosity of the curable composition for stereolithography, it is more preferable that 80% or more of all primary particles constituting the inorganic filler (B) have a particle diameter of 0.08 μm or more, and even more preferable that they have a particle diameter of 0.1 μm or more. From the viewpoint of further suppressing particle sedimentation, it is more preferable that 80% or more of all primary particles constituting the inorganic filler (B) have a particle diameter of 2.0 μm or less.

[0046] Here, the fact that 80% or more of all primary particles constituting the inorganic filler (B) have a particle diameter of 0.05 to 5.0 μm can be confirmed by the particle size distribution of the inorganic filler (B) measured by microscopy using a scanning electron microscope. That is, the inorganic filler (B) used to prepare the curable composition for stereolithography of the present disclosure is photographed with a scanning electron microscope, and the number of all primary particles (50 or more) observed within a unit field of view of the photograph: n (numbers) is counted, and the primary particle diameter (maximum diameter): X of each particle is measured. ｉ By measuring the particle size distribution of all primary particles, the particle size distribution can be determined. ｉwhere i is a natural number from 1 to n and represents the number of each measured primary particle. The average (primary) particle diameter: X (nm) is the sum of the particle diameters of all measured primary particles (primary particles with i = 1 to n): ΣX ｉ Using the formula: X = ΣX ｉ / n.

[0047] As the inorganic filler (B), inorganic powders and granules used as inorganic fillers in, for example, dental restorative materials can be used without any particular limitation. Suitable inorganic powders and granules include powders and granules made of metal (element), powders and granules made of metal oxides or metal composite oxides, powders and granules made of metal fluorides or metal salts such as carbonates, sulfates, silicates, hydroxides, chlorides, sulfites, phosphates, etc., and mixtures of these powders and granules. Particularly suitable inorganic filler constituent materials include amorphous silica, quartz; metal oxides such as alumina, zirconia, barium oxide, yttrium oxide, lanthanum oxide, and ytterbium oxide; silica-based composite oxides such as silica-zirconia, silica-titania, silica-titania-barium oxide, and silica-titania-zirconia; glasses such as borosilicate glass, aluminosilicate glass, and fluoroaluminosilicate glass; metal fluorides such as barium fluoride, strontium fluoride, yttrium fluoride, lanthanum fluoride, and ytterbium fluoride; inorganic carbonates such as calcium carbonate, magnesium carbonate, strontium carbonate, and barium carbonate; and metal sulfates such as magnesium sulfate and barium sulfate. From the viewpoint of the wear resistance of the cured body, it is most preferable to use silica-zirconia powder. When producing dental restorations, it is preferable to use powders and granules such as silica-zirconia, silica-titania, silica-titania-barium oxide, and silica-titania-zirconia because they have strong X-ray contrast. From the viewpoint of the abrasion resistance of the cured product, it is most preferable to use silica-zirconia powder and granules. As the inorganic filler (B), a combination of multiple types of powders and granules made of different materials may be used, or a combination of multiple types of powders and granules with different particle sizes may be used.

[0048] It is desirable to treat the inorganic filler (B) with a surface treatment agent, such as a silane coupling agent, in order to improve compatibility with the polymerizable monomer and improve mechanical strength and water resistance. The surface treatment may be carried out by a known method. Examples of silane coupling agents include methyl trimoxysilane, methyl triethoxysilane, methyl trichlorosilane, dimethyl dichlorosilane, trimethyl chlorosilane, vinyl trichlorosilane, vinyl triethoxysilane, vinyl tris(β-methoxyethoxy)silane, γ-methacryloyloxypropyl trimethoxysilane, methacryloxyoctyl-8-trimethoxysilane, γ-chloropropyl trimethoxysilane, γ-glycidoxypropyl methoxysilane, and hexamethyldisilazane.

[0049] [Photopolymerization initiator (C)] The photopolymerization initiator (C) generates radicals by activating light containing light of a specific wavelength λ (nm) in the ultraviolet or visible light region irradiated from a light source mounted in the stereolithography device, and has the function of radically polymerizing the polymerizable monomer. In other words, the photopolymerization initiator (C) must absorb light of the specific wavelength λ (nm) to generate radicals. The specific wavelength λ may be determined appropriately depending on the wavelength of the activating light used in the stereolithography device, as long as it is within the ultraviolet or visible light region. Examples of general-purpose stereolithography devices include SLA (Stereo Lithography Apparatus) type stereolithography devices that irradiate semiconductor laser light as activation light, DLP (Digital Light Processing) type stereolithography devices that irradiate projector light, and LCD (Liquid Crystal Display) type stereolithography devices that irradiate liquid crystal panel light, and light sources with activation light wavelengths of about 405 nm or about 385 nm are often used. In the present disclosure, 405 nm or 385 nm is preferably used as the specific wavelength λ, and the stereolithography device is preferably an SLA type, DLP type, or LCD type.

[0050] The content of the photopolymerization initiator (C) may be 0.05 to 5.0 parts by mass per 100 parts by mass of the radical polymerizable monomer (A). If the content of the photopolymerization initiator (C) is too high, burrs and the like tend to appear on the resulting three-dimensional optically shaped object, resulting in poor modeling accuracy. On the other hand, if the content of the photopolymerization initiator (C) is too low, modeling tends to be difficult in the molding process. Therefore, the content of the polymerization initiator is preferably 0.3 to 4.0 parts by mass, more preferably 0.5 to 3.0 parts by mass, per 100 parts by mass of the radical polymerizable monomer (A).

[0051] The photopolymerization initiator (C) may be appropriately selected from known photopolymerization initiators that satisfy the above conditions. The photopolymerization initiator to be selected is not particularly limited, and examples thereof include self-cleavage photopolymerization initiators, bimolecular hydrogen abstraction photopolymerization initiators, photoacid generators, and combinations thereof. These photopolymerization initiators may also be used in combination with photosensitizing dyes, electron-donating compounds, etc.

[0052] Suitable self-cleavage photopolymerization initiators include acylphosphine oxide compounds such as diphenyl(2,4,6-trimethylbenzoyl)phosphine oxide and phenylbis(2,4,6-trimethylbenzoyl)phosphine oxide; benzoketal compounds, benzyne compounds, α-aminoacetophenone compounds, α-hydroxyacetophenone compounds, titanocene compounds, and acyloxime compounds. Examples of photoacid generators include iodonium salt compounds such as p-isopropylphenyl-p-methylphenyliodonium tetrakispentafluorophenylborate salt; sulfonium salt compounds such as dimethylphenacylsulfonium hexafluoroantimonate salt; and halomethyl-substituted triazine compounds such as 2,4,6-tris(trichloromethyl)-s-triazine. Examples of photosensitizing dyes include ketone compounds, coumarin dyes, cyanine dyes, merocyanine dyes, thiazine dyes, azine dyes, acridine dyes, xanthene dyes, squarium dyes, pyrylium salt dyes, condensed polycyclic aromatic compounds (anthracene, perylene, etc.), thioxanthone compounds, etc. Examples of electron donating compounds include 4-dimethylaminobenzoic acid esters, 4-dimethylaminotoluene, p-dimethoxybenzene, 1,2,4-trimethoxybenzene, thiophene compounds, etc.

[0053] [Activating Light Absorber (D)] The curable composition for stereolithography disclosed herein contains 0.01 to 2.5 parts by mass of an activating light absorber (D) that absorbs the activating light irradiated from the stereolithography device and does not function as a photopolymerization initiator, per 100 parts by mass of the radically polymerizable monomer (A), to prevent excessive transmission of the activating light irradiated from the stereolithography device, thereby reducing the modeling accuracy of the three-dimensional stereolithography object. If the content of the activating light absorber (D) is too high, the light emitted from the light source of the stereolithography device during the molding process will not penetrate the curable composition for stereolithography, making it difficult to produce a three-dimensional stereolithography object. On the other hand, if the content of the activating light absorber (D) is too low, the modeling accuracy of the resulting three-dimensional stereolithography object will tend to decrease. Therefore, the content of the activated light absorber (D) is preferably 0.04 to 2.5 parts by mass, more preferably 0.08 to 2.0 parts by mass, and even more preferably 0.25 to 1.0 parts by mass, relative to 100 parts by mass of the radical polymerizable monomer (A).

[0054] The activating light absorber (D) is not particularly limited as long as it is a compound that absorbs activating light irradiated from a light source mounted in the stereolithography apparatus, and examples thereof include triazole compounds such as 2-(hydroxy-5-methylphenyl)-2H-benzotriazole and 2-(3-tert-butyl-2-hydroxy-5-methylphenyl)-5-chloro-2H-benzotriazole; and benzophenone compounds such as 2,4-dihydroxybenzophenone and 2-hydroxy-4-methoxybenzophenone.

[0055] [Polymerization Inhibitor (E)] The stereolithography curable composition of the present disclosure contains 0.01 to 5.0 parts by mass of a polymerization inhibitor (E) per 100 parts by mass of the radically polymerizable monomer (A) to improve its storage stability. If the content of the polymerization inhibitor (E) is too high, the stereolithography curable composition tends to be insufficiently cured during the molding process. On the other hand, if the content of the polymerization inhibitor (E) is too low, the storage stability of the stereolithography curable composition and the modeling accuracy of the resulting three-dimensional stereolithography object tend to decrease. Therefore, the content of the polymerization inhibitor (E) is preferably 0.01 to 5.0 parts by mass, more preferably 0.03 to 4.0 parts by mass, and even more preferably 0.05 to 2.5 parts by mass.

[0056] As the polymerization inhibitor (E), a compound that reacts with radicals generated in the curable composition for stereolithography to deactivate the radicals can be used, and examples thereof include di-tert-butyl-p-cresol and 4-methoxyphenol.

[0057] [Hyperbranched polymer (F)] A hyperbranched polymer is a multi-branched polymer obtained by one-step polymerization of a multifunctional monomer having two or more types of functional groups, and has branching points in the repeating units, with molecular chains that extend three-dimensionally.

[0058] As described in Patent Document 5, the hyperbranched polymer is blended for the purpose of reducing polymerization shrinkage of a dental curable composition used in a dental composite resin. In the present disclosure, such a hyperbranched polymer that is soluble in the radical polymerizable monomer (A) can be used without any particular limitation.

[0059] Here, "soluble in the radical polymerizable monomer (A)" means that the solubility in the radical polymerizable monomer (A) at 25°C (the limit amount (g) of the hyperbranched polymer (F) that dissolves in 100 g of the radical polymerizable monomer (A)) is 5 (g) or more, preferably 10 (g) or more. Therefore, in the curable composition for stereolithography, it is sufficient that a portion of the blended hyperbranched polymer (F) is dissolved, and it is not necessarily the case that the entire amount is dissolved, but it is preferable that the entire amount is dissolved. In other words, it is preferable that the hyperbranched polymer (F) is soluble in the radical polymerizable monomer (A) so that the entire amount blended is soluble.

[0060] In the present disclosure, 5 g or 10 g of the hyperbranched polymer (F) was added to 100 g of the radically polymerizable monomer (A), and whether or not it dissolved was evaluated visually at 25° C. For example, if 5 g of the hyperbranched polymer (F) does not dissolve, the solubility is less than 5 (g), and if all 5 g of the hyperbranched polymer (F) dissolves, the solubility is 5 (g) or more.

[0061] The radical polymerizable monomer (A) may be a combination of two or more polymerizable monomers. When the radical polymerizable monomer (A) is a combination of two or more polymerizable monomers, the solubility of the hyperbranched polymer (F) in the radical polymerizable monomer (A) may be 5 (g) or more relative to the mixture of two or more polymerizable monomers as the radical polymerizable monomer (A), and the polymerizable monomers constituting the mixture may include a polymerizable monomer whose solubility in the hyperbranched polymer (F) is less than 5 (g).

[0062] As the hyperbranched polymer (F), one that includes a first unit structure having four bonds, represented by the following formula (I), and a second unit structure that is at least one of the two unit structures represented by the following formula (IIA) and the following formula (IIB) (hereinafter also referred to as a "specific hyperbranched polymer") is preferred.

[0063] (Wherein, A is independently selected from C and R １and a single bond connecting the two, >C═O, —O—, —COO—, or —COO—CH ２ - indicates R １ represents a divalent saturated aliphatic hydrocarbon group or a divalent aromatic hydrocarbon group, and R ２ each independently represents a hydrogen atom or a methyl group.

[0064] (In the formula, R ３ , R ４ , and R ５ each independently represents a hydrogen atom, an alkyl group having 1 to 5 carbon atoms constituting the main chain, an alkoxycarbonyl group having 1 to 5 carbon atoms constituting the main chain, an aryl group, or a cyano group; R ６ represents an alkylene group having 4 to 10 carbon atoms constituting the main chain.

[0065] The first unit structure represented by the above formula (I) having four bonds is a unit structure that forms a multi-branched structure of the specific hyperbranched polymer. The four bonds can be bonded to the first unit structure represented by the above formula (I) or a second unit structure that is at least one of the two unit structures represented by the above formula (IIA) and formula (IIB). Here, the multi-branched structure is formed by bonding the first unit structures to each other via at least one of the four bonds. The second unit structure, which is an end group that divides the multi-branched structure, can be bonded to a maximum of three of the four bonds of the first unit structure.

[0066] The content ratio (molar ratio) of the first unit structure to the second unit structure contained in the specific hyperbranched polymer is preferably 3:7 to 7:3, and more preferably 4:6 to 6:4. By setting the molar ratio within the above range, it is possible to form a multi-branched structure with appropriate branching, and also to suppress a significant increase in viscosity of a solution in which the specific hyperbranched polymer is dissolved in a solvent.

[0067] R in the above formula (I) １ represents a divalent saturated aliphatic hydrocarbon group or a divalent aromatic hydrocarbon group.

[0068] The divalent saturated aliphatic hydrocarbon group may be either linear or cyclic. The number of carbon atoms in the divalent saturated aliphatic hydrocarbon group is not particularly limited, but is preferably 1 to 5, and more preferably 1 or 2. By limiting the number of carbon atoms to 5 or less, R １

[0033] Since the molecular chain portion represented by the formula (I) is shortened, entanglement between the radical polymerizable monomer (A) and the hyperbranched polymer (F) is suppressed, and as a result, an increase in viscosity of the curable composition for stereolithography can be suppressed. Examples of the divalent linear saturated aliphatic hydrocarbon group include a methylene group, an ethylene group, a propylene group, and a butylene group. Examples of the divalent cyclic saturated aliphatic hydrocarbon group include a cyclopropylene group and a cyclobutylene group.

[0069] The divalent aromatic hydrocarbon group may be a monocyclic group containing one benzene ring, a group having a fused ring structure containing two or more benzene rings, or a group having two or more benzene rings but not having a fused ring structure. The number of benzene rings contained in the divalent aromatic hydrocarbon group is not particularly limited, but is preferably 1 to 2. By limiting the number of benzene rings to 2 or less, entanglement between the radically polymerizable monomer (A) and the hyperbranched polymer (F) is suppressed, thereby suppressing an increase in viscosity of the curable composition for stereolithography. Examples of divalent aromatic hydrocarbon groups include a phenylene group, a naphthylene group, and a biphenylene group.

[0070] R in the above formula (IIA) and the above formula (IIB) ３ , R ４ , and R ５ each independently represents a hydrogen atom, an alkyl group having 1 to 5 carbon atoms constituting the main chain, an alkoxycarbonyl group having 2 to 6 carbon atoms constituting the main chain, an aryl group, or a cyano group.

[0071] Examples of alkyl groups include methyl groups, ethyl groups, and propyl groups. Examples of alkoxycarbonyl groups include methoxycarbonyl groups, ethoxycarbonyl groups, and propoxycarbonyl groups. Examples of aryl groups include phenyl groups. Note that, for alkyl groups and alkoxycarbonyl groups, by making the number of carbon atoms constituting the main chain 5 or less, particularly methyl groups or methoxycarbonyl groups, the main chain is shortened, thereby suppressing entanglement between the radical polymerizable monomer (A) and the hyperbranched polymer (F), and as a result, it is possible to suppress an increase in viscosity of the curable composition for stereolithography.

[0072] A portion of the hydrogen atoms of the alkyl group, alkoxycarbonyl group, and aryl group may be substituted with a substituent. The substituent is not particularly limited as long as it does not contain a structure or group that causes coloration (e.g., a reactive unsaturated bond, an amino group, a hydroxy group, etc.), and examples thereof include alkyl groups having 1 to 3 carbon atoms (e.g., methyl groups) and alkoxy groups having 1 to 3 carbon atoms (e.g., methoxy groups). Note that by using alkyl groups and alkoxy groups with 3 or fewer carbon atoms, particularly methyl or methoxy groups, the main chain is shortened, thereby suppressing entanglement between the radical polymerizable monomer (A) and the hyperbranched polymer (F), and as a result, an increase in the viscosity of the curable composition for stereolithography can be suppressed.

[0073] R in the above formula (IIB) ６ represents an alkylene group having 4 to 10 carbon atoms constituting the main chain.

[0074] Examples of alkylene groups include butylene, pentylene, and nonylene groups. Some of the hydrogen atoms of the alkylene group may be substituted with a substituent. The substituent is not particularly limited as long as it does not contain a structure or group that causes coloration (such as a reactive unsaturated bond, an amino group, or a hydroxy group), and examples include alkyl groups having 1 to 3 carbon atoms (such as a methyl group) and alkoxy groups having 1 to 3 carbon atoms (such as a methoxy group). Note that by making the number of carbon atoms constituting the main chain of the alkylene group 4 or more, R ６The possibility of the ring containing the alkylene group being distorted and destabilized, resulting in a reaction with surrounding substances and causing coloration, can be suppressed. Furthermore, by setting the number of carbon atoms constituting the main chain of the alkylene group to 10 or less, or by setting the number of carbon atoms of the alkyl group and alkoxy group selected as the substituent to 3 or less, particularly a methyl group or a methoxy group, the main chain is shortened, thereby suppressing entanglement of the radical polymerizable monomer (A) and the hyperbranched polymer (F), and as a result, it is possible to suppress an increase in viscosity of the curable composition for stereolithography.

[0075] The second unit structures represented by the formula (IIA) and the formula (IIB) are structures derived from raw material components used in the synthesis process of the specific hyperbranched polymer. Examples of the raw material components include known polymerization initiators, and preferably azo-based polymerization initiators disclosed in WO 2010 / 126140. However, only those that can assume the structure represented by the formula (IIA) or the formula (IIB) after the synthesis of the specific hyperbranched polymer is completed can be used.

[0076] Specific examples of the second unit structure represented by the above formula (IIA) include, for example, the following structural formulae A to K, and specific examples of the second unit structure represented by the above formula (IIB) include, for example, the following structural formulae L to M. These second unit structures represented by structural formulae A to M are particularly suitable in terms of the ease of availability of the specific hyperbranched polymer.

[0077]

[0078]

[0079]

[0080] The weight average molecular weight of the specific hyperbranched polymer is preferably 1,000 to 200,000. This weight average molecular weight is a polystyrene-equivalent weight average molecular weight determined by gel permeation chromatography (GPC) measurement using tetrahydrofuran as a solvent. From the viewpoints of solubility in the radically polymerizable monomer (A) and availability as a powder or granule composed of spherical particles with a hydrodynamic average diameter of approximately 5 to 40 nm, which facilitates uniform dispersion, the weight average molecular weight of the specific hyperbranched polymer is more preferably 5,000 to 100,000, and even more preferably 20,000 to 50,000. The hydrodynamic average diameter of the specific hyperbranched polymer is measured by dynamic light scattering in tetrahydrofuran at 40°C. The hydrodynamic average diameter of the specific hyperbranched polymer is preferably 5 to 20 nm, and more preferably 5 to 15 nm.

[0081] Such hyperbranched polymers made of powder or granules are commercially available, and examples of such products include "HYPERTECH" (registered trademark) manufactured by Nissan Chemical Industries, Ltd., "Hybrane" (registered trademark) manufactured by DSM, and "Boltorn" (registered trademark) manufactured by Perstop.

[0082] The content of the hyperbranched polymer (F) may be 0.3 to 10 parts by mass per 100 parts by mass of the radical polymerizable monomer (A). If the content of the hyperbranched polymer (F) is too high, the viscosity of the curable composition for stereolithography tends to increase. On the other hand, if the content of the hyperbranched polymer (F) is too low, the crack prevention effect tends to be insufficient. Therefore, the content of the hyperbranched polymer (F) is preferably 2 to 10 parts by mass, more preferably 2 to 8 parts by mass, and even more preferably 4 to 6 parts by mass per 100 parts by mass of the radical polymerizable monomer (A).

[0083] [Chain Transfer Agent (G)] The curable composition for stereolithography according to the present disclosure may contain 0.005 to 1.0 parts by mass of a chain transfer agent relative to 100 parts by mass of the radical polymerizable monomer (A) for the purposes of reducing shrinkage stress during stereolithography and improving the modeling accuracy of three-dimensional stereolithography objects. When the radical polymerizable monomer (A) contains 90% by mass or more of a polyfunctional (meth)acrylate radical polymerizable monomer (a), the radical polymerizable monomer (A) preferably contains 0.01 to 1.0 part by mass, preferably 0.03 to 0.3 part by mass, of the chain transfer agent (G) relative to 100 parts by mass of the radical polymerizable monomer (A), in order to further enhance the crack prevention effect.

[0084] Examples of the chain transfer agent (G) include thiol compounds such as butanethiol, thiophenol, mercaptoethanol, octylthiol, and lauryl mercaptan; α-alkylstyrene compounds such as 2,4-diphenyl-4-methyl-1-pentene (α-methylstyrene dimer) and 2-phenyl-1-propene (α-methylstyrene); and halogenated hydrocarbons substituted with at least one halogen atom such as carbon tetrachloride and ethylene bromide. Among these, α-alkylstyrene compounds are preferred, and α-methylstyrene dimer is more preferred, because of their high crack generation suppression effect.

[0085] [Other Components] (Thermal Polymerization Initiator) The curable composition for stereolithography according to the present disclosure may contain a thermal polymerization initiator as a polymerization initiator for secondary curing. In this case, it is preferable to use a thermal polymerization initiator with a 10-hour half-life temperature of 50 to 130°C, as it does not function during primary curing and remains effectively in the laminate. Examples of suitable thermal polymerization initiators include organic peroxides such as tert-butyl peroxylaurate and benzoyl peroxide; azo compounds such as azobutyronitrile and azobis(dimethylvaleronitrile); and the like.

[0086] When the curable composition for stereolithography according to the present disclosure contains a thermal polymerization initiator, the content thereof is usually 0.001 to 1.0 part by mass, preferably 0.005 to 0.3 part by mass, and more preferably 0.01 to 0.1 part by mass, relative to 100 parts by mass of the radical polymerizable monomer (A).

[0087] (Coloring Substance) The stereolithography curable composition of the present disclosure may contain a coloring substance to the extent that the effects of the present invention are not impaired. For example, when the stereolithography curable composition of the present disclosure is used to produce dental restorations such as inlays, onlays, crowns, and dentures, it is preferable to incorporate a coloring substance to reproduce the color of tooth crowns or the color of oral mucosa. The coloring substance may be a pigment or a dye. Examples of pigments include inorganic pigments such as titanium oxide, zinc oxide, zirconium oxide, zinc sulfide, aluminum silicate, calcium silicate, carbon black, iron oxide, copper chromite black, chromium oxide green, chrome green, violet, chrome yellow, lead chromate, lead molybdate, cadmium titanate, nickel titanium yellow, ultramarine blue, cobalt blue, bismuth vanadate, cadmium yellow, and cadmium yellow; and organic pigments such as monoazo pigments, diazo pigments, diazo condensation pigments, perylene pigments, and anthraquinone pigments.

[0088] <Method for Producing Curable Composition for Stereolithography> To produce the curable composition for stereolithography disclosed herein, the above-described components may be mixed to obtain a predetermined composition. From the viewpoint of stably producing a composition that reliably exhibits its effects, a preferred production method involves mixing a radically polymerizable monomer (A), a photopolymerization initiator (C), an activated light absorber (D), a polymerization inhibitor (E), and a hyperbranched polymer (F) to prepare a liquid composition in which at least a portion of the hyperbranched polymer is dissolved, and then mixing the resulting liquid composition with an inorganic filler (B). When preparing the liquid composition, it is preferable to mix a powder of a hyperbranched polymer having an average hydrodynamic diameter of 2 to 40 nm.

[0089] When mixing the components, it is preferable to mix them using a stirrer under the shielding of light that activates the photopolymerization initiator (C), for example, under red light, at room temperature or at a temperature of 40 to 80° C. until they become uniform. After mixing the inorganic filler (B), it is preferable to perform a degassing treatment.

[0090] When using a hyperbranched polymer (F) whose entire amount is soluble in the radically polymerizable monomer (A), it is preferable to use a method in which the mixing during preparation of the liquid composition is performed at 40 to 80°C, or a method in which the hyperbranched polymer (F) is dissolved in a volatile organic solvent, mixed, and then the organic solvent is removed to prepare the liquid composition, in order to ensure that the curable composition for stereolithography in which the hyperbranched polymer (F) is completely dissolved is used. Examples of volatile organic solvents used in the latter method include acetone, methyl ethyl ketone, acetonitrile, tetrahydrofuran, diethyl ether, pentane, hexane, ethyl acetate, methanol, ethanol, 1-propanol, isopropanol, water, chloroform, dichloromethane, and trichloroethane. These volatile organic solvents may be used alone, or two or more may be mixed together if they can be uniformly mixed. Known methods such as heating and reduced pressure can be used to remove the volatile organic solvent.

[0091] <Method for Manufacturing a Three-Dimensional Stereolithography Object> A three-dimensional stereolithography object can be manufactured by a liquid vat photopolymerization method using the stereolithography curable composition of the present disclosure. Specifically, a three-dimensional stereolithography object can be manufactured by sequentially performing the following steps: a liquid vat photopolymerization method in which, based on three-dimensional shape data representing the shape of the three-dimensional object, the height direction of the three-dimensional object is digitized and ranked, and two-dimensional shape data representing the cross-sectional shape of the three-dimensional object at each ranked height is generated; and a liquid vat photopolymerization method in which predetermined positions of the stereolithography curable composition of the present disclosure held in a vat are irradiated with ultraviolet or visible light to selectively cure the stereolithography curable composition present at those positions. Based on the two-dimensional shape data, the method sequentially forms and stacks modeling layers having shapes corresponding to the two-dimensional shapes at each height in the ranked order to obtain a laminate having a shape corresponding to the shape of the three-dimensional object; a cleaning step in which the laminate obtained in the molding step is washed with an organic solvent; and a secondary curing step in which the washed laminate is secondarily cured. According to this manufacturing method, it is possible to manufacture a three-dimensional optically shaped object that has high mechanical strength and is free from cracks on its actual surface.

[0092] In the method for producing a three-dimensional optically shaped object of the present disclosure, the molding process includes: a first step of irradiating a predetermined position of a stereolithography curable composition held in a tank with activating light based on two-dimensional shape data at a height of an initial ranking order, thereby curing the composition, and forming a modeling layer having a shape corresponding to the two-dimensional shape data, and using the modeling layer as a bonded layer; a second step of moving the bonded layer up or down and supplying a stereolithography curable composition immediately above or below the bonded layer in the tank; a third step of irradiating a predetermined position of the stereolithography curable composition supplied immediately above or below the bonded layer, based on two-dimensional shape data at a height next in the ranking order in the previous step, with activating light, thereby curing the composition, and forming a new modeling layer having a shape corresponding to the two-dimensional shape data, and bonding the new modeling layer to the bonded layer, thereby obtaining a laminate having the new modeling layer as a new bonded layer; and a fourth step of moving the laminate up or down and supplying a stereolithography curable composition immediately above or below the new bonded layer in the tank. It is preferable that the new bonded layer is used as the bonded layer in the third step, and the cycle consisting of the third step and the fourth step is repeated, and in the final third step, a new modeling layer is formed based on the two-dimensional shape data at the height of the final ranking order to obtain a laminate.

[0093] Such a liquid vat photopolymerization method including a molding step can be suitably carried out using a commercially available liquid vat photopolymerization device known as a 3D printer.

[0094] Examples of organic solvents used in the washing step include alcohol-based solvents such as ethanol, methanol, and isopropyl alcohol; ketone-based solvents such as acetone and methyl ethyl ketone; ether-based solvents such as diethyl ether, diisopropyl ether, tripropylene glycol monomethyl ether, and tetrahydrofuran; amide-based solvents such as N-methylpyrrolidone and dimethylacetamide; and halogen-based solvents such as methylene chloride and chloroform. Among these, alcohol-based solvents and ether-based solvents are preferred in terms of high washing efficiency, and alcohol-based solvents are more preferred in terms of low environmental impact.

[0095] In the secondary curing step, secondary curing is performed by additional irradiation with activating light, by heat treatment, or by both. When additional light irradiation is performed, the wavelength of the activating light irradiation is not particularly limited as long as it is a wavelength that can be absorbed by the photopolymerization initiator remaining in the laminate to generate radicals. The irradiation intensity of the additional light irradiation is set to 5 mW / cm so that the photopolymerization initiator remaining in the laminate generates a sufficient amount of radicals. ２ It is preferable that the power is 10 mW / cm or more. ２ More preferably, it is 30 mW / cm or more. ２ It is more preferable that the irradiation intensity is 10000 mW / cm or more. In addition, the irradiation time is not particularly limited, and is preferably 1 minute or more, more preferably 3 minutes or more, and even more preferably 5 minutes or more. If the irradiation intensity during the additional light irradiation is too strong, the three-dimensional optically shaped object may be excessively heated, which may cause cracks in the three-dimensional optically shaped object. Therefore, the irradiation intensity should be 10000 mW / cm or more. ２ It is preferable that:

[0096] Furthermore, when the curable composition for stereolithography according to the present disclosure contains a thermal polymerization initiator, the secondary curing can be carried out by heating the composition at a temperature of preferably 45 to 120°C, more preferably 50 to 90°C, and even more preferably 55 to 80°C.

[0097] The method for manufacturing a three-dimensional optically shaped object disclosed herein can also be used to manufacture dental restorations such as inlays, onlays, crowns, and dentures. When manufacturing such dental restorations, CAD data designed based on digital data obtained by scanning the intraoral shape of an individual patient or an intraoral model created for each individual patient can be used as three-dimensional shape data indicating the shape of the dental restoration (three-dimensional object) used in the molding process. This manufacturing method can manufacture dental restorations that have high mechanical strength and are free of cracks on their actual surfaces.

[0098] The present invention will be explained in more detail below with reference to examples, but the present invention is not limited to these examples.

[0099] The names, properties, abbreviations (when abbreviations are used), etc. of the various compounds used in each example and comparative example are shown below. <(A) Radically Polymerizable Monomer> [Polyfunctional (meth)acrylate-based radically polymerizable monomer (polyfunctional monomer) (a1)] UDMA: urethane dimethacrylate A-9300-1CL: caprolactone-modified tris-(2-acryloxyethyl) isocyanurate (manufactured by Shin-Nakamura Chemical Co., Ltd.) [Polyfunctional (meth)acrylate-based radically polymerizable monomer (polyfunctional monomer) (a2)] 3G: triethylene glycol dimethacrylate D-2.6E: bisphenol A ethylene glycol (EO) adduct dimethacrylate (number of EOs added: average 2.6) [Other radically polymerizable monomers (other monomers)] 9G: nonaethylene glycol dimethacrylate 1G: monoethylene glycol dimethacrylate ACMO: acryloylmorpholine

[0100] <(B) Inorganic Filler> Composition A: A filler consisting of a mixture of 70 parts by mass of Filler B1, which is spherical silica-zirconia powder particles (surface treated with gamma-methacryloyloxypropyltrimethoxysilane) having an average primary particle size of 0.5 μm, and 30 parts by mass of Filler B2, which is spherical silica-zirconia powder particles (surface treated with gamma-methacryloyloxypropyltrimethoxysilane) having an average primary particle size of 0.08 μm. Composition B: A filler consisting of a mixture of 70 parts by mass of Filler B1, which is spherical silica-zirconia powder particles (surface treated with gamma-methacryloyloxypropyltrimethoxysilane) having an average primary particle size of 0.5 μm, and 30 parts by mass of Filler B3, which is spherical silica-titania powder particles (surface treated with gamma-methacryloyloxypropyltrimethoxysilane) having an average primary particle size of 0.3 μm. Composition C: Spherical silica powder having an average primary particle size of 1000 nm (surface treated with γ-methacryloyloxypropyltrimethoxysilane)

[0101] <(C) Photopolymerization initiator> BTPO: phenylbis(2,4,6-trimethylbenzoyl)-phosphine oxide CQ: camphorquinone TPO: 2,4,6-trimethylbenzoyl-diphenylphosphine oxide

[0102] <(D) Activated Light Absorber> SS3: 2-(3-tert-butyl-2-hydroxy-5-methylphenyl)-5-chloro-2H-benzotriazole

[0103] <(E) Polymerization inhibitor> HQME: hydroquinone methyl ether BHT: dibutylhydroxytoluene

[0104] <(F) Hyperbranched Polymer> HBPA: poly(ethylene glycol dimethacrylate-methyl isobutyrate) (HYPERTEC HA-DMA-200, manufactured by Nissan Chemical Industries, Ltd., mass average molecular weight: 22,000, hydrodynamic average diameter: 5.2 nm, structural formula shown below)

[0105]

[0106] HBPB: poly(divinylbenzene-methyl isobutyrate) (HYPERTEC HA-DVB-500, manufactured by Nissan Chemical Industries, Ltd., mass average molecular weight: 48,000, hydrodynamic average diameter: 11.7 nm, structural formula shown below)

[0107]

[0108] <(G) Chain transfer agent> MSD: α-methylstyrene dimer

[0109] <Others> PMMA: Polymethyl methacrylate (mass average molecular weight: 250,000, average particle size: 30 μm) DMBE: p-dimethylaminobenzoic acid ethyl ester

[0110] The methods for evaluating various physical properties in the Examples and Comparative Examples are as follows. (1) Method for Measuring Solubility of Hyperbranched Polymer Each hyperbranched polymer was added to 10 g of a radically polymerizable monomer (monomer) mixture in each Example and Comparative Example, and the solubility was measured by visually evaluating whether it dissolved at 25°C. The meanings of the notations shown in the "Solubility" column in Tables 2 and 4 described below are as follows: <5: Solubility is less than 5 (g) (0.5 g of hyperbranched polymer does not dissolve in 10 g of monomer) ≧10: Solubility is 10 (g) or more (1 g of hyperbranched polymer dissolves in 10 g of monomer)

[0111] (2) Evaluation Method of Curable Composition for Stereolithography [Viscosity Measurement Method] 0.7 g of the curable composition for stereolithography of each Example and Comparative Example was placed on the sample stage of a rheometer MCR302 (manufactured by Anton Paar), and the paste was pressed using parallel plates with a diameter of 20 mm so that the sample thickness was 1 mm. Then, the viscosity was measured at a shear rate of 5 (s －１ The viscosity at 300 seconds after rotating the composition for 300 seconds was measured three times, and the average value was rounded to the nearest hundredth to obtain the viscosity of the curable composition for stereolithography in each Example and Comparative Example.

[0112] [Method for Evaluating Sedimentation of Inorganic Filler] 10 g of the curable composition for stereolithography of each Example and Comparative Example was taken and filled into a cylindrical light-shielding container having a diameter of 50 mm and a height of 28 mm, and then stored in a thermostatic chamber at 25° C. After 3 months, it was visually confirmed whether or not a sedimentation layer had formed on the bottom surface of the cylindrical light-shielding container.

[0113] (3) Manufacturing method of three-dimensional stereolithography 3D printer (DWS, DW029D; wavelength: 405 nm, irradiation intensity: 83 mW) The stereolithography curable composition of each example and comparative example was supplied to the resin tray (tank) of the 10 mm x 10 mm x 25 mm rectangular parallelepiped shape of stereolithography data (hereinafter abbreviated as "stl data"). A molded body (laminate) (composed of a cured product of the stereolithography curable composition) having a laminated structure was produced. Next, the obtained molded body was immersed in a plastic container filled with ethanol for 15 minutes, gently shaken to perform a washing process, then dried, and further subjected to additional light irradiation (secondary curing) for 30 minutes using a UV CURING UNIT UVIS-2 (DWS) to produce a three-dimensional stereolithography object.

[0114] (4) Evaluation Method of Three-Dimensional Photo-Fabricated Objects [Method for Measuring Bending Strength] After the crack evaluation described below, the evaluation sample was polished with #800 waterproof abrasive paper to form a prism of 2 mm × 2 mm × 25 mm. This test piece was attached to a testing machine (Shimadzu Corporation, Autograph AG5000D), and the three-point bending fracture strength was measured five times at a support distance of 20 mm and a crosshead speed of 1 mm / min, and the arithmetic average value was calculated.

[0115] [Crack Evaluation Method] The surface of the evaluation sample was observed with an optical microscope (50x magnification), and the same evaluation sample was also platinum-coated to a thickness of 5 nm and then observed with a scanning microscope (1000x magnification). The number and width of cracks observed on one surface of a 10 mm x 25 mm area of ​​the evaluation sample were confirmed and evaluated according to the following evaluation criteria. -Evaluation Criteria- A1: Up to 5 cracks were observed on the surface of the cured body, and all crack widths were less than 10 μm, which is within the acceptable range. A2: Up to 10 cracks were observed on the surface of the cured body, and all crack widths were less than 10 μm, which is within the acceptable range. A3: Up to 20 cracks were observed on the surface of the cured body, and all crack widths were less than 10 μm, which is within the acceptable range. B: Up to 20 cracks were observed on the surface of the cured body, and all crack widths were 10 to 40 μm. C: 20 or more cracks with a width of 10 to 40 μm were observed on the surface of the cured body.

[0116] Example 1 UDMA (80 parts by mass), 9G (20 parts by mass), BTPO (1.4 parts by mass), SS3 (0.7 parts by mass), HQME (0.1 parts by mass), and BHT (0.1 parts by mass) were stirred and mixed until uniform, and then HBPA (5 parts by mass) was added and further stirred and mixed, and visual inspection was performed to confirm that no undissolved residue remained. The solubility of HBPA in the mixture of UDMA and 9G was 10 (g) or more. Inorganic filler composition A (150 parts by mass) was added to the resulting mixture, and the mixture was stirred and mixed until uniform, followed by degassing to prepare a liquid curable composition for stereolithography.

[0117] The viscosity of the obtained curable composition for stereolithography was measured, and sedimentation of the inorganic filler was evaluated. The viscosity was found to be 7000 mPa·s, and no sedimentation occurred. Furthermore, a three-dimensional stereolithography object was produced using the obtained curable composition for stereolithography, and its bending strength and cracking were evaluated. The bending strength was found to be 121 MPa, and the cracking evaluation result was "A3." An optical microscope image (magnification: 50x) taken during observation for crack evaluation in Example 1 is shown in FIG. 1 .

[0118] Examples 2, 5 to 19, 21 to 23: Stereolithography curable compositions were prepared in the same manner as in Example 1, except that the formulation of the stereolithography curable composition was changed as shown in Tables 1 and 2 below. The numbers in parentheses in Tables 1 and 2 indicate the blend amount (unit: parts by mass) of each component. Furthermore, three-dimensional stereolithography objects were produced using the obtained stereolithography curable compositions. The stereolithography curable compositions and three-dimensional stereolithography objects were evaluated in the same manner as in Example 1, and the results are shown in Table 4 below.

[0119] Example 3: HBPA (10 parts by weight) was added to acetone and stirred to mix, and visual inspection confirmed that no residue remained. UDMA (80 parts by weight), 3G (20 parts by weight), BTPO (1.4 parts by weight), SS3 (0.7 parts by weight), HQME (0.1 parts by weight), and BHT (0.1 parts by weight) were stirred and mixed until uniform, after which an acetone solution of HBPA was added and further stirred and mixed. After confirming uniformity, the acetone was removed using a rotary evaporator. Next, inorganic filler composition A (150 parts by weight) was added to the resulting mixture, and the mixture was stirred and mixed until uniform. The mixture was degassed to prepare a liquid curable composition for stereolithography. Furthermore, a three-dimensional stereolithography object was fabricated using the resulting curable composition for stereolithography. The curable composition for stereolithography and the three-dimensional stereolithography object were evaluated in the same manner as in Example 1, and the results are shown in Table 4 below.

[0120] Example 4: UDMA (80 parts by mass), 3G (20 parts by mass), BTPO (1.4 parts by mass), SS3 (0.7 parts by mass), HQME (0.1 parts by mass), and BHT (0.1 parts by mass) were mixed and stirred until uniform, and then HBPA (7 parts by mass) was added. The mixture was stirred and mixed while heated at 45°C, and visual inspection confirmed that no residue remained. Inorganic filler composition A (150 parts by mass) was added to the resulting mixture, and the mixture was stirred and mixed until uniform. The mixture was degassed to prepare a liquid curable composition for stereolithography. Furthermore, a three-dimensional stereolithography object was fabricated using the resulting curable composition for stereolithography. The results of evaluation of the curable composition for stereolithography and the three-dimensional stereolithography object in the same manner as in Example 1 are shown in Table 4 below.

[0121] Example 20: UDMA (80 parts by weight), 3G (20 parts by weight), BTPO (1.4 parts by weight), SS3 (0.7 parts by weight), HQME (0.1 parts by weight), and BHT (0.1 parts by weight) were mixed and stirred until uniform. HBPA (5 parts by weight) and inorganic filler composition A (150 parts by weight) were added to the resulting mixture, which was then mixed and stirred until uniform. The mixture was degassed to prepare a liquid curable composition for stereolithography. Furthermore, a three-dimensional stereolithography object was fabricated using the resulting curable composition for stereolithography. The results of evaluation of the curable composition for stereolithography and the three-dimensional stereolithography object in the same manner as in Example 1 are shown in Table 4 below.

[0122] Comparative Examples 1 and 2: Stereolithography curable compositions were prepared in the same manner as in Example 1, except that the formulation of the stereolithography curable composition was changed as shown in Table 3 below. The numbers in parentheses in Table 3 indicate the blend amount of each component (unit: parts by mass). Furthermore, a three-dimensional stereolithography object was produced using the obtained stereolithography curable composition. The stereolithography curable composition and the three-dimensional stereolithography object were evaluated in the same manner as in Example 1, and the results are shown in Table 4 below. Furthermore, an optical microscope image (magnification: 50x) taken during observation for crack evaluation in Comparative Example 1 is shown in Figure 2.

[0123] Comparative Examples 3 and 4 Stereolithography curable compositions were prepared in the same manner as in Example 1, except that the formulation of the stereolithography curable composition was changed as shown in Table 3 below. The obtained stereolithography curable compositions were evaluated in the same manner as in Example 1, and the results are shown in Table 4 below. The stereolithography curable compositions of Comparative Examples 3 and 4 had high viscosities exceeding 100,000 mP·s, and could not be used for modeling using a 3D printer.

[0124] Comparative Example 5 A curable composition for stereolithography was prepared according to the method described in Example 1 of Patent Document 3. Specifically, UDMA (70 parts by mass), ACMO (30 parts by mass), inorganic filler composition C (100 parts by mass), TPO (3.0 parts by mass), and BHT (0.05 parts by mass) were stirred and mixed to prepare a curable composition for stereolithography. Furthermore, a three-dimensional stereolithography object was fabricated using the resulting curable composition for stereolithography. The results of evaluation of the curable composition for stereolithography and the three-dimensional stereolithography object in the same manner as in Example 1 are shown in Table 4 below. An optical microscope image (magnification: 50x) taken during observation for crack evaluation in Comparative Example 5 is shown in Figure 3.

[0125]

[0126]

[0127]

[0128]

[0129] As shown in Table 4, the curable compositions for stereolithography of Examples 1 to 23 had appropriate viscosities and no sedimentation of the inorganic filler occurred. Furthermore, the three-dimensional stereolithography objects of Examples 1 to 23 had high bending strength, and the cracks observed on the surface were small in width and in number.

[0130] In contrast, the stereolithography curable composition of Comparative Example 1, which had the same composition as Examples 3 to 8 except for not containing the hyperbranched polymer, exhibited a tendency for the inorganic filler to settle. Furthermore, numerous cracks were present on the surface of the 3D stereolithography object of Comparative Example 1. The stereolithography curable composition of Comparative Example 2, which had the same composition as Examples 5 and 8 except for containing polymethyl methacrylate instead of the hyperbranched polymer, had a higher viscosity than the stereolithography curable compositions of Examples 5 and 8, and the inorganic filler was more likely to settle. Furthermore, the 3D stereolithography object of Comparative Example 2 had low bending strength and numerous cracks were observed on the surface. The stereolithography curable compositions of Comparative Examples 3 and 4, which contained more than 250 parts by mass of inorganic filler per 100 parts by mass of radical polymerizable monomer, had a high viscosity exceeding 100,000 mP·s and could not be modeled using a 3D printer. The stereolithography curable composition of Comparative Example 5 was prepared according to the method described in Patent Document 3, and numerous cracks were observed on the resulting 3D stereolithography object.

Claims

1. A curable composition for three-dimensional optical modeling, comprising: 100 parts by mass of a radically polymerizable monomer (A) that is liquid at 25°C; 50 to 250 parts by mass of an inorganic filler (B); 0.05 to 5.0 parts by mass of a photopolymerization initiator (C) that absorbs activating light and generates radicals; 0.01 to 2.5 parts by mass of an activating light absorber (D) that absorbs activating light; 0.01 to 5.0 parts by mass of a polymerization inhibitor (E); and 0.3 to 10 parts by mass of a hyperbranched polymer (F) that is soluble in the radically polymerizable monomer (A).

2. The hyperbranched polymer (F) is represented by the following formula (I): (In the formula, A is independently selected from C and R １ and a single bond connecting the two, >C=O, -O-, -COO-, or -COO-CH ２ - indicates R １ represents a divalent saturated aliphatic hydrocarbon group or a divalent aromatic hydrocarbon group, R ２ each independently represents a hydrogen atom or a methyl group; and a first unit structure having four bonds and represented by the following formula (IIA) and the following formula (IIB): (In the formula, R ３ , R ４ , and R ５ each independently represents a hydrogen atom, an alkyl group having 1 to 5 carbon atoms constituting the main chain, an alkoxycarbonyl group having 2 to 6 carbon atoms constituting the main chain, an aryl group, or a cyano group; R ６ represents an alkylene group having 4 to 10 carbon atoms constituting a main chain.

3. The curable composition for three-dimensional photopolymerization according to claim 1, wherein the content of the hyperbranched polymer (F) is 2 to 10 parts by mass per 100 parts by mass of the radically polymerizable monomer (A).

4. 90% by mass or more of the radical polymerizable monomer (A) is composed of a polyfunctional (meth)acrylate radical polymerizable monomer (a) having two or more (meth)acryloyl groups in the molecule and having 5 to 25 atoms constituting the main chain of the divalent group intervening between the two or more (meth)acryloyl groups in the molecule, and the polyfunctional (meth)acrylate radical polymerizable monomer (a) is composed of a polyfunctional (meth)acrylate radical polymerizable monomer (a1) having at least one bond selected from the group consisting of a urethane bond, a urea bond, and an isocyanurate ring, and a polyfunctional (meth)acrylate radical polymerizable monomer (a2) other than the above, 2. The curable composition for three-dimensional optical modeling according to claim 1, wherein 40 to 90 mass % of the radical polymerizable monomer (A) is the polyfunctional (meth)acrylate radical polymerizable monomer (a1), and 10 to 60 mass % of the radical polymerizable monomer (a2).

5. The curable composition for three-dimensional optical modeling according to claim 1, further comprising 0.005 to 1.0 part by mass of a chain transfer agent (G).

6. The curable composition for three-dimensional optical modeling according to claim 1, which is used as the liquid photocurable composition in three-dimensional optical modeling, in which a laminate having a shape corresponding to the shape of the three-dimensional object is obtained by digitizing and ranking the height direction of the three-dimensional object from three-dimensional shape data indicating the shape of the three-dimensional object and generating two-dimensional shape data indicating the cross-sectional shape of the three-dimensional object at each ranked height, and using a liquid vat photopolymerization method in which ultraviolet or visible light is irradiated to a predetermined position of the liquid photocurable resin composition held in a vat to selectively harden the liquid photocurable resin composition present at that position, and forming and stacking modeling layers having shapes corresponding to the two-dimensional shapes at each height in the order of the ranking based on the two-dimensional shape data.

7. A method for producing a curable composition for three-dimensional photopolymerization as described in claim 1, comprising mixing the radical polymerizable monomer (A), the photopolymerization initiator (C), the activated light absorber (D), the polymerization inhibitor (E), and the hyperbranched polymer (F) to prepare a liquid composition in which at least a portion of the hyperbranched polymer is dissolved, and then mixing the liquid composition with the inorganic filler (B).

8. A method for producing a curable composition for three-dimensional photopolymerization according to claim 7, wherein when preparing the liquid composition, a powder of a hyperbranched polymer having a hydrodynamic average diameter in tetrahydrofuran of 2 to 40 nm as measured by dynamic light scattering is mixed.

9. A method for producing a three-dimensional optically modeled object, comprising: digitizing and ranking the height direction of the three-dimensional object from three-dimensional shape data indicating the shape of the three-dimensional object, generating two-dimensional shape data indicating the cross-sectional shape of the three-dimensional object at each ranked height; and using a liquid vat photopolymerization method in which ultraviolet or visible activating light is irradiated to a predetermined position of a liquid photocurable resin composition held in a vat to selectively harden the liquid photocurable resin composition present at that position, to sequentially form and stack modeling layers having shapes corresponding to the two-dimensional shapes at each height in the order of the ranking based on the two-dimensional shape data, thereby obtaining a laminate having a shape corresponding to the shape of the three-dimensional object; and using the curable composition for three-dimensional optical modeling according to claim 1 as the liquid photocurable resin composition.

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