Photocurable resin composition and resin mold for making a template

Abstract

A photocurable resin composition used in a liquid tank photopolymerization method for molding a resin mold serving as a template, which balances molding accuracy and sintering residue. The photocurable resin composition according to the embodiment contains (A) a monofunctional (meth)acryl monomer, (B) at least one multifunctional monomer selected from the group consisting of a multifunctional (meth)acrylate and a multifunctional urethane (meth)acrylate, (C) crosslinking polymethacrylate particles, (D) a photopolymerization initiator, and (E) an organic dye. The content of the (C) component is 60 to 140 parts by mass relative to 100 parts by mass of the total content of the (A) component and the (B) component.

Description

Technical Field

[0001] This invention relates to a light-curable resin composition and a resin mold for template making obtained by molding using the same. Background Technology

[0002] Traditionally, the templates used to fabricate denture bases were made as follows: A plaster mold was created to fit the shape of the patient's mouth. Then, curing resin was poured into the plaster mold. After the resin cured, the cured resin was checked in the patient's mouth and fine-tuned to obtain a resin mold. This resin mold was used as a prototype to create the denture base. The denture base was then fabricated by pouring the material that forms the denture base into the template and allowing it to cure.

[0003] The aforementioned operations involve numerous steps; therefore, a solution using 3D printers to reduce these steps has been proposed. For example, Patent Documents 1 and 2 propose a method for manufacturing dental prostheses, such as denture bases, using a 3D printer without templates, from a photocurable resin containing monofunctional and polyfunctional (meth)acryloyl monomers and a photopolymerization initiator via vat photopolymerization.

[0004] Existing technical documents

[0005] Patent documents

[0006] Patent Document 1: International Publication No. 2018 / 025943

[0007] Patent Document 2: International Publication No. 2018 / 105463 Summary of the Invention

[0008] To reduce the number of steps involved in fabricating the denture base, a 3D printer using liquid bath photopolymerization is considered for fabricating the resin mold used to create the template. In this case, the resin mold must have excellent molding precision while suppressing volume shrinkage caused by curing, and the sintering residue must be minimized and eliminated during the sintering process.

[0009] The purpose of this invention is to balance molding accuracy and sintering residue in a photocurable resin composition used in molding a resin mold for template making by liquid bath photopolymerization.

[0010] The present invention includes the embodiments shown below.

[0011] [1] A photocurable resin composition is used in molding a template-making resin mold by a liquid bath photopolymerization method, comprising (A) a monofunctional (meth)acrylamide monomer, (B) at least one polyfunctional monomer selected from polyfunctional (meth)acrylates and polyfunctional urethane (meth)acrylates, (C) crosslinked polymethacrylate particles, (D) a photopolymerization initiator and (E) an organic dye, wherein the content of the above-mentioned component (C) is 60 to 140 parts by mass relative to the total content of the above-mentioned component (A) and component (B) of 100 parts by mass.

[0012] [2] The photocurable resin composition according to [1], wherein the above-mentioned component (D) comprises phenyl bis(2,4,6-trimethylbenzoyl)phosphine oxide.

[0013] [3] According to the photocurable resin composition of [1] or [2], wherein the content of the above-mentioned component (E) is 0.01 to 1 part by mass relative to the total content of the above-mentioned component (A) and component (B) of 100 parts by mass.

[0014] [4] The photocurable resin composition according to any one of [1] to [3], wherein the content of the above-mentioned component (D) is 1.0 to 11 parts by mass relative to the total content of the above-mentioned component (A) and component (B) of 100 parts by mass.

[0015] [5] The photocurable resin composition according to any one of [1] to [4], wherein the mass ratio of the contents of the above-mentioned component (A) and the above-mentioned component (B), component (C), component (D) and component (E) is in the range of (A+B) / C / D / E = 41 to 63 / 35 to 58 / 0.4 to 6.5 / 0.0041 to 0.62.

[0016] [6] The photocurable resin composition according to any one of [1] to [5], wherein the viscosity at 25°C, as measured using an E-type viscometer, is 20 to 2500 mPa·s.

[0017] [7] A resin mold for template making is obtained by molding a photocurable resin composition as described in any one of [1] to [6] using a liquid bath photopolymerization 3D printer.

[0018] If it is a photocurable resin composition according to an embodiment of the present invention, the resin mold can be formed by a 3D printer using a liquid bath photopolymerization method. The volume shrinkage rate after curing is small and the molding accuracy is excellent. Furthermore, there is little sintering residue when the template is sintered and the sintering residue is excellent. Detailed Implementation

[0019] The photocurable resin composition of the embodiment comprises (A) a monofunctional (meth)acrylamide monomer, (B) a multifunctional monomer selected from at least one of polyfunctional (meth)acrylates and polyfunctional urethane (meth)acrylates, (C) crosslinked polymethacrylate particles, (D) a photopolymerization initiator, and (E) an organic dye.

[0020] In this specification, "(meth)acryloyl monomer" means acryloyl monomer or methacryloyl monomer. "(meth)acrylic acid" means acrylic acid or methacrylic acid. "(meth)acrylate" means acrylate or methacrylate.

[0021] In the above-described photocurable resin composition, components (A) and (B) are resin components that are photocured by the photopolymerization initiator of component (D). By adding cross-linked polymethacrylate particles of component (C), the volume shrinkage rate after curing can be reduced, thereby improving molding accuracy. Furthermore, by using the organic dye of component (E), the formability of the 3D printer using the bath photopolymerization method can be ensured, and sintering residues during template sintering can be eliminated. Specifically, in the case of photoforming using the bath photopolymerization method, the photocurable resin composition requires a light-masking effect so that it does not cure except in areas where it should cure. If a pigment is used as a colorant with this effect, when the resin mold obtained from the photoforming is used as a prototype to sinter the template, sintering residues of the resin mold remain in the template, requiring removal. According to this embodiment, an organic dye is used to obtain the masking effect required for photoforming based on the bath photopolymerization method. Since the dye is organic, it does not become a sintering residue, thus ensuring the formability of the 3D printer and reducing the step of removing sintering residues.

[0022] [(A) ingredient]

[0023] The monofunctional (meth)acryloyl monomer that is component (A) is a monomer having one (meth)acryloyl group in one molecule. Here, (meth)acryloyl group means acryloyl group or methacryloyl group.

[0024] As (A) a monofunctional (meth)acrylamide monomer, examples include monofunctional (meth)acrylates, monofunctional N-substituted (meth)acrylamides, etc., and any one of them or two or more in combination can be used. Here, (meth)acrylamide means acrylamide or methacrylamide.

[0025] Specific examples of monofunctional (meth)acrylates include ethyl (meth)acrylate, n-butyl (meth)acrylate, tert-butyl (meth)acrylate, isobutyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, isodecanyl (meth)acrylate, lauryl (meth)acrylate, cyclohexyl (meth)acrylate, dicyclopentyl (meth)acrylate, dicyclopentenyl (meth)acrylate, isobornyl (meth)acrylate, adamantane (meth)acrylate, cyclohexyl (meth)acrylate, tetrahydrofurfuryl (meth)acrylate, methyl (2-methyl-2-ethyl-1,3-dioxolane-4-yl)acrylate, benzyl (meth)acrylate, phenyl (meth)acrylate, phenyl benzyl (meth)acrylate, phenoxyethyl (meth)acrylate, diethylene glycol (meth)acrylate, tetraethylene glycol (meth)acrylate, nonylphenoxyethyl (meth)acrylate, and phenoxybenzyl (meth)acrylate. They can be used in any one or in combination of two or more. Among them, (meth)acrylates having an aromatic ring in the molecule and / or (meth)acrylates having an alicyclic structure in the molecule are preferred. Here, the alicyclic structure also includes a portion of it having heteroatoms such as oxygen atoms and nitrogen atoms.

[0026] Specific examples of monofunctional N-substituted (meth)acrylamides include (meth)acryloylmorpholine, N,N-dimethyl (meth)acrylamide, N,N-diethyl (meth)acrylamide, N,N-dimethylaminopropyl (meth)acrylamide, N-methyl (meth)acrylamide, N-ethyl (meth)acrylamide, and N-isopropyl (meth)acrylamide. Any one of these or two or more can be used in combination.

[0027] In one embodiment, (A) the monofunctional (meth)acrylamide monomer may comprise a monofunctional (meth)acrylate (A-a) having an aromatic ring in the molecule. In this case, the content of (A-a) component in 100% by mass of (A) the monofunctional (meth)acrylamide monomer may be 20-100% by mass or 50-97% by mass.

[0028] In one embodiment, (A) the monofunctional (meth)acrylamide monomer may comprise a monofunctional (meth)acrylate (A-a) having an aromatic ring in the molecule and a (meth)acrylate (A-b) having an alicyclic structure in the molecule and / or a monofunctional N-substituted (meth)acrylamide (A-c). In this case, the content of (A-a) component in 100% by mass of (A) the monofunctional (meth)acrylamide monomer may be 20-98% by mass, and the content of (A-b) component and / or (A-c) component may be 2-80% by mass.

[0029] [(B) Component]

[0030] (B) The component is at least one polyfunctional monomer selected from polyfunctional (meth)acrylates and polyfunctional urethane (meth)acrylates, having a plurality of (meth)acryloyloxy groups per molecule. (B) The polyfunctional monomer typically has two or three (meth)acryloyloxy groups per molecule. Here, (meth)acryloyloxy means acryloyloxy or methacryloyloxy.

[0031] Specific examples of multifunctional (meth)acrylates include ethylene glycol dimethacrylate, triethylene glycol dimethacrylate, glycerol dimethacrylate, 1,6-hexanediol dimethacrylate, 1,9-nonanediol dimethacrylate, alkylene oxide-modified bisphenol A dimethacrylate, dimethyloltricyclodecane dimethacrylate, diethylene glycol dimethacrylate, 2-hydroxy-3-acryloyloxypropyl (meth)acrylate, polyethylene glycol dimethacrylate, tri(acryloyloxyethyl) isocyanurate, trimethylolpropane triacrylate, alkylene oxide-modified trimethylolpropane trimethacrylate, alkylene oxide-modified pentaerythritol pentamethacrylate, and alkylene oxide-modified dipentaerythritol hexamethacrylate. Any one of these or two or more can be used in combination.

[0032] Polyfunctional urethane (meth)acrylates are urethane compounds having multiple (meth)acryloyloxy groups in one molecule. Examples of polyfunctional urethane (meth)acrylates include, for instance, compounds obtained by reacting a polyisocyanate compound with a polyol compound to obtain a urethane prepolymer with terminal hydroxyl groups, and then reacting that prepolymer with (meth)acrylic acid; or compounds obtained by reacting a polyisocyanate compound with a polyol compound to obtain a urethane prepolymer with terminal isocyanate groups, and then reacting that prepolymer with a hydroxyl-containing (meth)acrylate; or compounds obtained by reacting a polyisocyanate compound with a hydroxyl-containing (meth)acrylate, etc.

[0033] Examples of polyisocyanate compounds include aromatic polyisocyanates, aliphatic polyisocyanates, and alicyclic polyisocyanates. Examples of polyol compounds include polyether polyols, polyester polyols, polycarbonate polyols, and polyolefin polyols. Examples of (meth)acrylates containing hydroxyl groups include, for example, 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, ethylene glycol mono(meth)acrylate, propylene glycol mono(meth)acrylate, pentaerythritol tri(meth)acrylate, trimethylolpropane di(meth)acrylate, and dipentaerythritol penta(meth)acrylate.

[0034] The content of component (B) is not particularly limited, but can be 3 to 50 parts by mass or 5 to 40 parts by mass relative to the total content of components (A) and (B) of 100 parts by mass.

[0035] [(C) Component]

[0036] The cross-linked polymethacrylate particles of component (C) are microparticles of cross-linked polymethacrylate. Combining them with component (C) can improve the molding precision after curing. Examples of polymethacrylates constituting the cross-linked polymethacrylate particles of (C) include polymethyl methacrylate, polyethyl methacrylate, polypropyl methacrylate, and other alkyl polymethacrylates, and one or more of these can be used. The alkyl group of the polymethacrylate preferably has 2 or fewer carbon atoms.

[0037] (C) The average particle size of the cross-linked polymethacrylate particles is not particularly limited, for example, it can be 1–50 μm or 2–20 μm. Here, the average particle size is the volume average diameter determined by the Coulter counter method.

[0038] The content of component (C) is preferably 60 to 140 parts by mass relative to the total content of components (A) and (B) of 100 parts by mass. By having a content of component (C) of 60 parts by mass or more, the volume shrinkage rate during curing of the photocurable resin composition can be reduced, thereby improving the molding accuracy after curing. By having a content of component (C) of 140 parts by mass or less, the viscosity of the photocurable resin composition can be reduced. From this viewpoint, the content of component (C) is more preferably 70 to 130 parts by mass, and even more preferably 80 to 120 parts by mass.

[0039] [(D) component]

[0040] As a photopolymerization initiator for component (D), it is not particularly limited if it can initiate the photoradical polymerization of components (A) and (B). Examples of photopolymerization initiators for (D) include alkyl phenyl ketone compounds, acylphosphine oxide compounds, oxime ester compounds, thioxanthone compounds, anthraquinone compounds, etc. They can be used in any one or in combination of two or more.

[0041] Examples of alkyl phenyl ketone compounds include, for example, benzoylayl methyl ketal compounds such as 2,2'-dimethoxy-1,2-diphenylethane-1-one, 2-hydroxy-2-methyl-1-phenylpropane-1-one, 1-hydroxycyclohexylphenyl ketone, 1-[4-(2-hydroxyethoxy)phenyl]-2-hydroxy-2-methyl-1-propane-1-one, 2-hydroxy-1-{4-[4-(2-hydroxy-2-methylpropanoyl)benzyl]phenyl}-2-methylpropane-1-one, 2-methyl-1-(4-methylthiophenyl)-2-morpholinopropane-1-one, and 2-benzylmethyl-2-dimethylamino-1-(4-morpholinophenyl)-1-butanone, etc. Examples of acylphosphine oxide compounds include, for example, phenylbis(2,4,6-trimethylbenzoyl)phosphine oxide and 2,4,6-trimethylbenzoyl diphenylphosphine oxide. They can be used individually or in combination of two or more.

[0042] In one embodiment, to correspond with an LED (light-emitting diode) light source, the (D) photopolymerization initiator comprises an acylphosphine oxide compound (D-a) as a long-wavelength component, more preferably comprising phenylbis(2,4,6-trimethylbenzoyl)phosphine oxide. In this case, the content of the (D-a) component (more preferably phenylbis(2,4,6-trimethylbenzoyl)phosphine oxide) in 100% by mass of the (D) photopolymerization initiator can be 10-50% by mass or 15-35% by mass.

[0043] In one embodiment, the (D) photopolymerization initiator preferably comprises an acylphosphine oxide compound (D-a) and an alkyl phenyl ketone compound (D-b), more preferably comprising phenyl bis(2,4,6-trimethylbenzoyl)phosphine oxide and an alkyl phenyl ketone compound (more preferably an α-hydroxyalkylphenyl ketone compound). Thus, when using an LED light source, the surface of the photocurable resin composition can be cured with the alkyl phenyl ketone compound (D-b), and cured to the interior with the acylphosphine oxide compound (D-a), thereby improving the curability of the photocurable resin composition. In this case, the content of the (D-a) component (more preferably phenyl bis(2,4,6-trimethylbenzoyl)phosphine oxide) in 100% by mass of the (D) photopolymerization initiator can be 10-50% by mass or 15-35% by mass, and the content of the (D-b) component (more preferably an α-hydroxyalkylphenyl ketone compound) can be 50-90% by mass or 65-85% by mass.

[0044] The content of component (D) is preferably 1 to 11 parts by mass relative to the total content of components (A) and (B) of 100 parts by mass. When the content of component (D) is 1 part by mass or more, the photopolymerization of components (A) and (B) can be promoted. When the content of component (D) is 11 parts by mass or less, deep curing becomes easier. The content of component (D) is more preferably 1.5 to 8 parts by mass, and even more preferably 2 to 6 parts by mass.

[0045] [(E) component]

[0046] The organic dye, as component (E), is a dye composed of organic compounds, using pigments of organic compounds that are soluble in a liquid-curable resin composition. By using organic dyes as colorants, the formability of 3D printers based on bath photopolymerization can be ensured, and sintering residues during template sintering can be eliminated.

[0047] Specific examples of organic dyes include CI Acid Yellow 1, 3, 11, 36, 42, 73; CI Acid Red 22, 26, 51, 87, 88, 92, 94, etc. They can be used alone or in combination of two or more.

[0048] The content of component (E) is preferably 0.01 to 1 part by mass relative to the total content of components (A) and (B) of 100 parts by mass. When the content of component (E) is 0.01 parts by mass or more, the masking effect based on organic dyes can be improved, thereby improving the formability of the 3D printer. When the content of component (E) is 1 part by mass or less, deep curing becomes easier. The content of component (E) is more preferably 0.03 to 0.5 parts by mass, and even more preferably 0.05 to 0.2 parts by mass.

[0049] As needed, the photocurable resin composition of this embodiment may also contain other components besides those described above. Examples of other components include, for instance, monofunctional monomers other than component (A), polyfunctional monomers other than component (B), plasticizers, etc. Among these, inorganic fillers and pigments that can become sintering residues are preferably not substantially included in the photocurable resin composition. Here, "substantially not included" means that the content is less than 0.01% by mass relative to 100% by mass of the photocurable resin composition.

[0050] In one embodiment, the mass ratio of components (A) and (B), (C), (D), and (E) in the photocurable resin composition is preferably in the range of (A+B) / C / D / E = 41–63 / 35–58 / 0.4–6.5 / 0.0041–0.62. That is, the total content of components (A) to (E) is set to 100% by mass, preferably the total content of components (A) and (B) is 41–63% by mass, the content of component (C) is 35–58% by mass, the content of component (D) is 0.4–6.5% by mass, and the content of component (E) is 0.0041–0.62% by mass.

[0051] From the viewpoint of moldability based on bath photopolymerization, the viscosity of the photocurable resin composition, measured using an E-type viscometer at 25°C, is preferably 20–2500 mPa·s. A viscosity of 20 mPa·s or higher indicates good moldability based on bath photopolymerization. A viscosity of 2500 mPa·s or lower indicates good moldability of each layer during bath photopolymerization. This viscosity can be 40 mPa·s or higher, or 70 mPa·s or higher. This viscosity can be 2000 mPa·s or lower, or 1500 mPa·s or lower.

[0052] The photocurable resin composition of this embodiment is used as a resin composition for photoforming a resin mold used to make a template by bath photopolymerization. Therefore, the resin mold for making a template in one embodiment is obtained by molding the above-mentioned photocurable resin composition using a bath photopolymerization 3D printer, and is a cured product of the above-mentioned photocurable resin composition.

[0053] Submerged photopolymerization (SPR) is a layer-by-layer modeling method using a 3D printer. It involves selectively irradiating a photocurable resin composition stored in a submerged tank with light from either the top or bottom side, causing it to solidify and layer. Examples of light irradiation methods include scanning laser (SLA) using a galvano mirror and surface exposure (DLP) where a projector uniformly exposes cross-sectional images of each layer. The irradiating light source can be, for example, ultraviolet light or a longer wavelength LED light source.

[0054] As a bath photopolymerization method, for example, a photocurable resin composition placed in a bath can be irradiated with a laser in a predetermined pattern from its upper surface, causing a one-layer amount of the photocurable resin composition located in the gap between the liquid surface and the molding stage to cure. This process is then repeated by lowering the molding stage by only one layer, supplying the cured material with photocurable resin composition, and irradiating it with a laser to cure it, thereby obtaining a three-dimensional model. Alternatively, a photocurable resin composition placed in a transparent bath can be irradiated with light in a predetermined pattern from its lower surface by laser scanning or surface exposure using a projector, causing a one-layer amount of the photocurable resin composition located in the gap between the bottom surface of the bath and the molding stage to cure. This process is then repeated by raising the molding stage by only one layer, supplying the cured material with photocurable resin composition, and irradiating it with light to cure it, thereby obtaining a three-dimensional structure. Such models based on the bath photopolymerization method can be produced, for example, using a commercially available bath photopolymerization 3D printer.

[0055] The resin mold formed according to this embodiment is used as a prototype when making templates. Templates are made by sintering inorganic materials such as plaster, clay, terracotta, and metal. The use of templates is not particularly limited; for example, in one embodiment, it can be a template for shaping dental restorations such as denture bases.

[0056] One possible method for manufacturing the template is as follows: using the aforementioned resin mold as a prototype, an inorganic template material such as plaster is arranged around the resin mold, and the inorganic material is sintered by heating in this state. The resin mold disappears due to the heating during sintering. According to this embodiment, when the template is sintered using the resin mold, sintering residue can be suppressed and eliminated as much as possible, thus reducing or eliminating the step of removing sintering residue after the sintering process.

[0057] In one embodiment, a method for manufacturing a template for shaping dental prostheses such as denture bases can be described as follows: The shape of the patient's oral cavity is measured using three-dimensional measurement; a resin mold is produced using a liquid bath photopolymerization 3D printer from the aforementioned photocurable resin composition based on the obtained measurement data; an inorganic material such as plaster is placed around the obtained resin mold; the inorganic material is then heated in this state to sinter, causing the resin mold to disappear, thus obtaining a template. A dental prosthesis can be manufactured by flowing a material for forming the dental prosthesis into the obtained template and allowing it to cure.

[0058] It should be noted that the various numerical ranges, including the above-mentioned proportions and viscosity, can be arbitrarily combined with their upper and lower limits. All these combinations are described in this specification as preferred numerical ranges.

[0059] Example

[0060] The present invention will be further described in detail below through embodiments, but the present invention is not limited to the following embodiments.

[0061] <Measurement and Evaluation Methods>

[0062] [Viscosity]

[0063] The viscosity of the photocurable resin composition was determined using an E-type viscometer at 25°C.

[0064] [Volume shrinkage rate (molding accuracy)]

[0065] A photocurable resin composition was coated to a thickness of 100 μm and cured under the following UV irradiation conditions. The specific gravity of the resin before and after curing at 20°C was measured using a hydrometer, and the volume shrinkage rate was calculated using the following formula. The smaller the volume shrinkage rate, the better the molding accuracy.

[0066] Volume shrinkage rate (%) = [(specific gravity after curing - specific gravity before curing) / specific gravity after curing] × 100

[0067] [Tensile strength, elongation, elastic modulus]

[0068] A photocurable resin composition was coated to a thickness of 100 μm and cured under the following UV irradiation conditions. The cured resin was cut into strips with a width of 5 mm and used as test pieces. The strips were stretched at a speed of 50 mm / min using an Autograph (manufactured by TENSILON and ORIENTEC) to determine the tensile strength at break (tensile strength MPa), elongation % and elastic modulus MPa.

[0069] [UV irradiation conditions]

[0070] As the UV irradiation device, a conveyor belt-type UV curing unit equipped with UV-LED lamps (World Engineering Co., Ltd.) was used. The irradiation conditions were set with a cumulative irradiance of 4500 mJ / cm². 2 .

[0071] [3D Printability]

[0072] Using a photocurable resin composition, fabricate a 5cm × 5cm × 1cm tooth-shaped model under the following 3D printing process conditions. A case where the tooth-shaped model can be fabricated is rated as "0" (good moldability), and a case where the model falls during fabrication or is not completed as specified is rated as "×" (poor moldability).

[0073] [Sintering Residue]

[0074] Using a photocurable resin composition, a 5cm × 5cm × 1cm three-dimensional model was produced under the following 3D printing process conditions. After placing the obtained three-dimensional model in an electric furnace at 750°C for 1 hour, the sintering residue was visually evaluated. No sintering residue was rated as "0" (good sintering residue), and the presence of sintering residue was rated as "×" (poor sintering residue).

[0075] [3D Printer Process Conditions]

[0076] A light-curing system (Titan2, manufactured by Kudo3D) using direct light penetration (DLP) was used to create three-dimensional models of a specified shape from a photocurable resin composition. The layer spacing was set to 0.1 mm, and the light exposure time was set to 60 seconds for the first layer, 30 seconds for layers 2-10, and 10 seconds for layers beyond the 10th layer. The resulting three-dimensional models were then ultrasonically cleaned in isopropyl alcohol.

[0077] [Examples 1-4 and Comparative Examples 1-5]

[0078] According to the proportions (parts by weight) listed in Table 1 below, the components were mixed and stirred using a disperser to obtain the photocurable resin compositions of Examples 1-4 and Comparative Examples 2-6. As Comparative Example 1, a commercially available product, Press-E-Cast (manufactured by envisionTEC), was prepared as a photocurable resin composition for general photoforming. The details of each component in Table 1 are as follows.

[0079] (A-1) Isoborneol acrylate: Trade name "IBXA", manufactured by Osaka Organic Chemical Industry Co., Ltd.

[0080] (A-2) Acryloylmorpholine: Trade name "ACMO", manufactured by KJ Chemicals Corporation.

[0081] (A-3) Phenoxyethyl acrylate: Trade name "NEW FRONTIER PHE", manufactured by Daiichi Kogyo Pharmaceutical Co., Ltd.

[0082] (B-1) 10 mol ethylene oxide modified bisphenol A diacrylate: trade name "NEW FRONTIER BPE-10", manufactured by Daiichi Kogyo Pharmaceutical Co., Ltd.

[0083] (B-2) Tris(acryloyloxyethyl) isocyanurate: Trade name "NEW FRONTIER TEICA", manufactured by Daiichi Kogyo Pharmaceutical Co., Ltd.

[0084] (B-3) Bifunctional carbamate acrylate: Trade name "NEW FRONTIER R-1220", manufactured by Daiichi Kogyo Pharmaceutical Co., Ltd.

[0085] (C-1) Cross-linked polymethyl methacrylate particles: Trade name "ENEOS Uni-Powder NMB-0520C", manufactured by JXTG Energy Corporation, average particle size: 5μm

[0086] (D-1)1-Hydroxycyclohexylphenyl ketone: Trade name "Omnirad 184", manufactured by IGM Resins B.V.

[0087] (D-2)Phenylbis(2,4,6-trimethylbenzoyl)phosphine oxide: Trade name "Omnirad 819", manufactured by IGMresins B.V.

[0088] (E-1) Organic dyes: Dyes containing C1 Acid Yellow 42: Trade name "VARI FAST ORANGE 1225", manufactured by Orient Chemical Industry Co., Ltd.

[0089] The viscosity, volume shrinkage, tensile strength, elongation, elastic modulus, 3D printing properties, and sintering residue of the photocurable resin compositions of Examples 1-4 and Comparative Examples 1-5 were measured and evaluated. The results are shown in Table 1.

[0090] Table 1

[0091]

[0092] As shown in Table 1, the photocurable resin composition of Comparative Example 1, which is usually sold, contains pigments as colorants, and therefore leaves sintering residues. As a result, there is a risk of poor molding caused by sintering residues when using a resin mold made from this photocurable resin composition.

[0093] In contrast, the photocurable resin compositions of Examples 1-4 exhibit low volume shrinkage, resulting in excellent molding precision and good 3D printability. Furthermore, they are free of sintering residues, demonstrating excellent sintering residue characteristics. Additionally, the photocurable resin compositions of Examples 1-4 have sufficiently low viscosity and good flexibility.

[0094] On the other hand, compared with Examples 1-4, the photocurable resin compositions of Comparative Examples 2 and 3 contained less or no cross-linked polymethyl methacrylate particles, resulting in a large volume shrinkage rate and poor molding accuracy. In the photocurable resin composition of Comparative Example 4, 3D printability was further poor, and the test pieces were brittle and could not be measured for evaluations such as tensile strength. In the photocurable resin composition of Comparative Example 5, since it did not contain organic dyes, the tooth-shaped model produced by the 3D printer differed significantly from the design, resulting in poor 3D printability.

[0095] The foregoing has described some embodiments of the present invention, but these embodiments are presented as examples and are not intended to limit the scope of the invention. These embodiments may be implemented in various other forms, and various omissions, substitutions, and modifications may be made without departing from the spirit of the invention. These embodiments, their omissions, substitutions, modifications, etc., are included in the same scope and spirit of the invention as those described in the scope of the patent claim and their equivalents.

Claims

1. A photocurable resin composition used in molding a template-making resin mold by bath photopolymerization, comprising a monofunctional (meth)acryloyl monomer A, at least one polyfunctional monomer B selected from polyfunctional (meth)acrylates and polyfunctional urethane (meth)acrylates, crosslinked polymethacrylate particles C, a photopolymerization initiator D, and an organic dye E. The content of component C is 60-140 parts by mass relative to the total content of components A and B, which is 100 parts by mass. Component D contains acylphosphine oxide compounds and alkyl phenyl ketone compounds. The content of inorganic filler and pigment is less than 0.01% by mass relative to 100% by mass of the photocurable resin composition.

2. The photocurable resin composition according to claim 1, wherein, The acylphosphine oxide compound is phenylbis(2,4,6-trimethylbenzoyl)phosphine oxide, and the alkyl phenyl ketone compound is α-hydroxyalkylphenyl ketone compound.

3. The photocurable resin composition according to claim 1 or 2, wherein, The content of component E is 0.01 to 1 part by mass relative to the total content of component A and component B, which is 100 parts by mass.

4. The photocurable resin composition according to claim 1 or 2, wherein, The content of component D is 1 to 11 parts by mass relative to the total content of component A and component B, which is 100 parts by mass.

5. The photocurable resin composition according to claim 1 or 2, wherein, The mass ratio of the contents of component A, component B, component C, component D, and component E is in the range of (A+B) / C / D / E = 41~63 / 35~58 / 0.4~6.5 / 0.0041~0.

62.

6. The photocurable resin composition according to claim 1 or 2, wherein, The viscosity at 25°C, measured using an E-type viscometer, ranges from 20 to 2500 mPa·s.

7. A resin mold for template making, which is formed by a liquid bath photopolymerization 3D printer from the photocurable resin composition according to any one of claims 1 to 6.

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