JP2022119652A - Photocurable resin composition and resin mold for preparing template - Google Patents

Abstract

To combine molding accuracy and sintering residue in a photocurable resin composition used for molding a resin mold for template preparation with a vat photopolymerization method.SOLUTION: A photocurable resin composition according to the embodiment comprises: at least one kind of polyfunctional monomer selected from the group consisting of (A) monofunctional (meth)acrylic monomers, (B) polyfunctional (meth)acrylic acid esters and polyfunctional urethane (meth)acrylates; (C) crosslinked poly(meth)acrylic acid ester particles; (D) a photopolymerization initiator; and (E) an organic dye. A content of the component (C) is 60 to 140 pts.mass to 100 pts.mass of the total content of components (A) and (B).SELECTED DRAWING: None

Description

TECHNICAL FIELD Embodiments of the present invention relate to a photocurable resin composition and a resin mold for producing a casting mold molded using the same.

Conventionally, a mold for producing a denture base is produced as follows. A gypsum mold that conforms to the shape of the patient's oral cavity is produced, then a curable resin is poured into the gypsum mold, the curable resin is cured, and then the cured resin is confirmed in the patient's oral cavity, and finely A resin mold is obtained by performing the adjustment, and a casting mold is produced using the obtained resin mold as a prototype. A denture base can be produced by pouring a material for forming the denture base into this mold and hardening it.

The above work involves many steps, and it has been proposed to use a 3D printer to reduce the steps. For example, in Patent Documents 1 and 2, a 3D printer is used without using a template, and a photocurable resin containing monofunctional and polyfunctional (meth)acrylic monomers and a photopolymerization initiator is processed by a liquid bath photopolymerization method. It has been proposed to manufacture dental prostheses such as denture bases.

WO2018/025943 WO2018/105463

In order to reduce the manufacturing process of the denture base, it is conceivable to use a liquid bath photopolymerization type 3D printer for manufacturing the resin mold for manufacturing the mold. In that case, the resin mold should have excellent molding precision by suppressing volumetric shrinkage due to curing, and should minimize sintering residue and disappear when the mold is sintered using the resin mold. Desired.

An object of an embodiment of the present invention is to achieve both molding accuracy and sintering residue resistance in a photocurable resin composition used for molding a resin mold for mold production by a liquid bath photopolymerization method.

The present invention includes embodiments shown below.
[1] A photocurable resin composition used for molding a resin mold for making a mold by a liquid bath photopolymerization method, comprising (A) a monofunctional (meth) acrylic monomer, (B) a polyfunctional (meth) ) at least one polyfunctional monomer selected from the group consisting of acrylates and polyfunctional urethane (meth)acrylates, (C) crosslinked polymethacrylate particles, (D) a photopolymerization initiator, and (E) an organic A photocurable resin composition containing a dye, wherein the content of component (C) is 60 to 140 parts by mass per 100 parts by mass of the total content of components (A) and (B).
[2] The photocurable resin composition according to [1], wherein the component (D) contains phenylbis(2,4,6-trimethylbenzoyl)phosphine oxide.
[3] [1] or [2] wherein the content of the component (E) is 0.01 to 1 part by mass per 100 parts by mass of the total content of the component (A) and the component (B) ] The photocurable resin composition as described in .
[4] The content of the component (D) is 1.0 to 11 parts by mass per 100 parts by mass of the total content of the component (A) and the component (B) [1] to [3 ] The photocurable resin composition according to any one of the above items.
[5] The mass ratio of the contents of the (A) component, the (B) component, the (C) component, the (D) component, and the (E) component is (A+B)/C/D/E = 41 to 63/35 to 58/0.4 to 6.5/0.0041 to 0.62, the photocurable resin composition according to any one of [1] to [4] .
[6] The photocurable resin composition according to any one of [1] to [5], which has a viscosity of 20 to 2500 mPa·s at 25° C. measured using an E-type viscometer.
[7] A resin mold for making a casting mold, which is molded from the photocurable resin composition according to any one of [1] to [6] using a liquid-tank photopolymerization type 3D printer.

With the photocurable resin composition according to the embodiment of the present invention, it is possible to mold a resin mold with a liquid bath photopolymerization type 3D printer, and the volume shrinkage rate after curing is small and the molding accuracy is excellent. There is little sintering residue when sintering and molding, and it is excellent in sintering residue property.

The photocurable resin composition according to the embodiment is at least selected from the group consisting of (A) monofunctional (meth)acrylic monomers, (B) polyfunctional (meth)acrylic acid esters and polyfunctional urethane (meth)acrylates. It comprises a kind of multifunctional monomer, (C) crosslinked polymethacrylate particles, (D) a photoinitiator, and (E) an organic dye.

As used herein, "(meth)acrylic monomer" represents an acrylic monomer or a methacrylic monomer. "(Meth)acrylic acid" represents acrylic acid or methacrylic acid. "(Meth)acrylate" represents acrylate or methacrylate.

In the above photocurable resin composition, the components (A) and (B) are resin components photocurable by the photopolymerization initiator of component (D), and crosslinked polymethacrylate particles of component (C) are added thereto. By adding, the volume shrinkage rate after curing can be reduced and the molding accuracy can be improved. In addition, by using the organic dye of the component (E), it is possible to eliminate sintering residue when the mold is sintered while ensuring moldability with a liquid bath photopolymerization type 3D printer. Specifically, when stereolithography is performed by the liquid bath photopolymerization method, the photocurable resin composition is required to have a light shielding effect so that it does not cure in areas other than the areas that should be cured. If a pigment is used as a coloring agent for this purpose, when the stereolithographic resin mold is used as the original mold and the mold is sintered, the sintering residue of the resin mold will remain in the mold, and a process for removing it will be required. necessary. According to this embodiment, an organic dye is used to obtain the shielding effect necessary for stereolithography by the liquid bath photopolymerization method, and the organic dye does not become a sintering residue, so moldability in a 3D printer is improved. It is possible to eliminate the sintering residue and reduce the number of processes while ensuring the quality.

[(A) component]
The monofunctional (meth)acrylic monomer as component (A) is a monomer having one (meth)acryloyl group in one molecule. Here, the (meth)acryloyl group represents an acryloyl group or a methacryloyl group.

(A) Monofunctional (meth)acrylic monomers include, for example, monofunctional (meth)acrylic acid esters and monofunctional N-substituted (meth)acrylamides. You may Here, (meth)acrylamide represents acrylamide or methacrylamide.

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, isodecyl (meth)acrylate, lauryl (meth)acrylate, cyclohexyl (meth)acrylate, dicyclopentanyl (meth)acrylate, dicyclopentenyl (meth)acrylate, isobornyl (meth)acrylate, adamantyl (meth)acrylate, cyclohexyl (meth)acrylate ) acrylate, tetrahydrofurfuryl (meth)acrylate, (2-methyl-2-ethyl-1,3-dioxolan-4-yl)methyl (meth)acrylate, benzyl (meth)acrylate, phenyl (meth)acrylate, phenylbenzyl (meth)acrylate, phenoxyethyl (meth)acrylate, phenoxydiethylene glycol (meth)acrylate, phenoxytetraethylene glycol (meth)acrylate, nonylphenoxyethyl (meth)acrylate, phenoxybenzyl (meth)acrylate and the like. Any one of these may be used, or two or more thereof may be used in combination. Among these, it is preferable to use a (meth)acrylic acid ester having an aromatic ring in the molecule and/or a (meth)acrylic acid ester having an alicyclic structure in the molecule. Here, the alicyclic structure also includes a structure partially having a heteroatom such as an oxygen atom or a nitrogen atom.

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, N-isopropyl(meth)acrylamide and the like. Any one of these may be used, or two or more thereof may be used in combination.

In one embodiment, (A) a monofunctional (meth)acrylic monomer may include a monofunctional (meth)acrylic acid ester (Aa) having an aromatic ring in the molecule. In this case, the content of component (Aa) in 100% by mass of (A) monofunctional (meth)acrylic monomer may be 20 to 100% by mass, or may be 50 to 97% by mass.

In one embodiment, (A) a monofunctional (meth)acrylic monomer has an alicyclic structure in the molecule (meth) together with a monofunctional (meth)acrylic acid ester (Aa) having an aromatic ring in the molecule (meth ) acrylic acid esters (Ab) and/or monofunctional N-substituted (meth)acrylamides (Ac). In this case, the content of the component (Aa) is 20 to 98% by mass in 100% by mass of the (A) monofunctional (meth)acrylic monomer, and the content of the component (Ab) and/or the component (Ac) is The content may be 2 to 80% by mass.

[(B) component]
Component (B) is at least one polyfunctional monomer selected from the group consisting of polyfunctional (meth)acrylic acid esters and polyfunctional urethane (meth)acrylates, and has a plurality of (meth)acryloyloxy groups in one molecule. have (B) The polyfunctional monomer usually has two or three (meth)acryloyloxy groups in one molecule. Here, the (meth)acryloyloxy group represents an acryloyloxy group or a methacryloyloxy group.

Specific examples of polyfunctional (meth)acrylic acid esters include ethylene glycol di(meth)acrylate, triethylene glycol di(meth)acrylate, glycerin di(meth)acrylate, 1,6-hexanediol di(meth)acrylate, 1,9-nonanediol di(meth)acrylate, alkylene oxide-modified bisphenol A di(meth)acrylate, dimethylol-tricyclodecane di(meth)acrylate, diethylene glycol di(meth)acrylate, 2-hydroxy-3-acryloyloxy Propyl (meth)acrylate, polyethylene glycol di(meth)acrylate, tris(acryloyloxyethyl) isocyanurate, trimethylolpropane triacrylate, alkylene oxide-modified trimethylolpropane tri(meth)acrylate, alkylene oxide-modified pentaerythritol penta(meth) Acrylate, alkylene oxide-modified dipentaerythritol hexa(meth)acrylate, and the like. Any one of these may be used, or two or more thereof may be used in combination.

A polyfunctional urethane (meth)acrylate is a urethane compound having a plurality of (meth)acryloyloxy groups in one molecule. Examples of polyfunctional urethane (meth)acrylates include those obtained by reacting a hydroxy-terminated urethane prepolymer obtained by reacting a polyisocyanate compound and a polyol compound with (meth)acrylic acid, and polyisocyanate obtained by reacting a terminal isocyanate group-containing urethane prepolymer obtained by reacting a polyol compound with a hydroxyl group-containing (meth)acrylate, or by reacting a polyisocyanate compound with a hydroxyl group-containing (meth)acrylate. and those obtained by

Examples of polyisocyanate compounds include aromatic polyisocyanates, aliphatic polyisocyanates, and alicyclic polyisocyanates. Examples of polyol compounds include polyether-based polyols, polyester-based polyols, polycarbonate-based polyols, and polyolefin-based polyols. Examples of hydroxy group-containing (meth)acrylates include 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, dipentaerythritol penta(meth)acrylate and the like.

The content of component (B) is not particularly limited. .

[(C) component]
The crosslinked polymethacrylate particles of component (C) are fine particles of crosslinked polymethacrylate, and the addition of component (C) can improve molding accuracy after curing. (C) The polymethacrylate constituting the crosslinked polymethacrylate particles includes, for example, polyalkyl methacrylates such as polymethyl methacrylate, polyethyl methacrylate and polypropyl methacrylate. A combination of species or more may be used. The number of carbon atoms in the alkyl group of polyalkyl methacrylate is preferably 2 or less.

The average particle size of the (C) crosslinked polymethacrylate particles is not particularly limited, and may be, for example, 1 to 50 μm or 2 to 20 μm. Here, the average particle diameter is the volume average diameter measured by the Coulter Counter method.

The content of component (C) is preferably 60 to 140 parts by mass per 100 parts by mass of the total content of components (A) and (B). When the content of component (C) is 60 parts by mass or more, the volume shrinkage rate of the photocurable resin composition during curing can be reduced, and molding accuracy after curing can be improved. (C) When content of a component is 140 mass parts or less, the viscosity of a photocurable resin composition can be reduced. From such a point of view, the content of component (C) is more preferably 70 to 130 parts by mass, more preferably 80 to 120 parts by mass.

[(D) Component]
The photopolymerization initiator that is the component (D) is not particularly limited as long as it can initiate photoradical polymerization of the components (A) and (B). (D) Photopolymerization initiators include, for example, alkylphenone compounds, acylphosphine oxide compounds, oxime ester compounds, thioxanthone compounds, and anthraquinone compounds. These may be used singly or in combination of two or more.

Examples of alkylphenone compounds include benzyl methyl ketal compounds such as 2,2′-dimethoxy-1,2-diphenylethan-1-one, 2-hydroxy-2-methyl-1-phenylpropan-1-one, 1 -hydroxycyclohexylphenyl ketone, 1-[4-(2-hydroxyethoxy)phenyl]-2-hydroxy-2-methyl-1-propan-1-one, 2-hydroxy-1-{4-[4-(2 α-hydroxyalkylphenone compounds such as -hydroxy-2-methylpropionyl)benzyl]phenyl}-2-methylpropan-1-one, 2-methyl-1-(4-methylthiophenyl)-2-morpholinopropane-1 -one, 2-benzylmethyl-2-dimethylamino-1-(4-morpholinophenyl)-1-butanone and other aminoalkylphenone compounds. Examples of acylphosphine oxide compounds include phenylbis(2,4,6-trimethylbenzoyl)phosphine oxide and 2,4,6-trimethylbenzoyldiphenylphosphine oxide. These can be used either singly or in combination of two or more.

In one embodiment, (D) the photoinitiator contains an acylphosphine oxide compound (Da), which is a long wavelength component, in order to correspond to an LED (light emitting diode) light source, more preferably phenylbis ( 2,4,6-trimethylbenzoyl)phosphine oxide. In this case, the content of component (Da) (more preferably phenylbis(2,4,6-trimethylbenzoyl)phosphine oxide) in 100% by mass of (D) photopolymerization initiator is 10 to 50% by mass. Well, it may be 15 to 35% by mass.

In one embodiment, (D) the photopolymerization initiator preferably comprises an acylphosphine oxide compound (Da) and an alkylphenone compound (Db), more preferably phenylbis(2,4,6 -trimethylbenzoyl)phosphine oxide and an alkylphenone compound (more preferably an α-hydroxyalkylphenone compound). As a result, when an LED light source is used, while the outermost surface of the photocurable resin composition is cured with the alkylphenone compound (Db), the interior can be cured with the acylphosphine oxide compound (Da). It is possible to improve the curability of the photocurable resin composition. In this case, the content of component (Da) (more preferably phenylbis(2,4,6-trimethylbenzoyl)phosphine oxide) in 100% by mass of (D) photopolymerization initiator is 10 to 50% by mass. The content of component (Db) (more preferably α-hydroxyalkylphenone compound) may be 50 to 90% by mass, or 65 to 85% by mass.

The content of component (D) is preferably 1 to 11 parts by mass per 100 parts by mass of the total content of components (A) and (B). When the content of component (D) is 1 part by mass or more, photopolymerization of components (A) and (B) can be promoted. When the content of component (D) is 11 parts by mass or less, deep-part hardening can be facilitated. The content of component (D) is more preferably 1.5 to 8 parts by mass, more preferably 2 to 6 parts by mass.

[(E) Component]
The organic dye, which is the component (E), is a dye made of an organic compound, and an organic compound dye that is soluble in the liquid photocurable resin composition is used. By using an organic dye as a coloring agent, it is possible to eliminate sintering residue when sintering a mold while ensuring moldability by a liquid bath photopolymerization type 3D printer.

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 and the like. These can be used either singly or in combination of two or more.

The content of component (E) is preferably 0.01 to 1 part by mass per 100 parts by mass of the total content of components (A) and (B). When the content of the component (E) is 0.01 parts by mass or more, the shielding effect of the organic dye can be enhanced to improve moldability with a 3D printer. When the content of component (E) is 1 part by mass or less, deep-part hardening can be facilitated. The content of component (E) is more preferably 0.03 to 0.5 parts by mass, more preferably 0.05 to 0.2 parts by mass.

If necessary, the photocurable resin composition according to the present embodiment may contain components other than those described above. Other components include, for example, monofunctional monomers other than the above component (A), polyfunctional monomers other than the above component (B), and plasticizers. However, it is preferable that the photocurable resin composition does not substantially contain inorganic fillers and pigments that may become sintering residues. Here, "substantially not contained" means that the content is less than 0.01% by mass with respect to 100% by mass of the photocurable resin composition.

In one embodiment, the mass ratio of the contents of components (A) and (B), (C), (D), and (E) contained in the photocurable resin composition is (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 100% by mass, the total content of components (A) and (B) is 41 to 63% by mass, and the content of component (C) is 35 to 58% by mass, the content of component (D) is preferably 0.4 to 6.5% by mass, and the content of component (E) is preferably 0.0041 to 0.62% by mass. .

The viscosity of the photocurable resin composition is preferably 20 to 2500 mPa·s at 25° C. measured using an E-type viscometer, from the viewpoint of moldability by the liquid bath photopolymerization method. When the viscosity is 20 mPa·s or more, moldability by the liquid bath photopolymerization method is improved. When the viscosity is 2500 mPa·s or less, the moldability of each layer during liquid bath photopolymerization is improved. The viscosity may be 40 mPa·s or more, or 70 mPa·s or more. The viscosity may be 2000 mPa·s or less, or 1500 mPa·s or less.

The photocurable resin composition according to the present embodiment is used as a resin composition for stereolithography of a resin mold for producing a casting mold by a liquid bath photopolymerization method. Therefore, the resin mold for mold preparation according to one embodiment is molded from the photocurable resin composition using a liquid bath photopolymerization 3D printer, and the cured product of the photocurable resin composition is.

The liquid bath photopolymerization method is a type of additive manufacturing method using a 3D printer, and selectively irradiates the photocurable resin composition stored in the liquid bath with light from the upper surface side or the lower surface side. It is a method of laminating by hardening one layer at a time. Examples of the light irradiation method include a method of scanning laser light with a galvanomirror or the like (SLA), and a surface exposure method (DLP) of collectively exposing a cross-sectional image of each layer using a projector. As the light to be irradiated, for example, ultraviolet light may be used, or an LED light source with a longer wavelength may be used.

As the liquid bath photopolymerization method, for example, a photocurable resin composition placed in a liquid bath is irradiated with a laser beam from the upper surface thereof in a predetermined pattern, and a layer existing in the gap between the liquid surface and the modeling table is formed. The photocurable resin composition is cured for 10 minutes, and then the position of the molding table is lowered by one layer to supply the photocurable resin composition onto the cured product, which is irradiated with laser light to be cured. A three-dimensional object may be obtained by repeating the operation. Alternatively, the photocurable resin composition placed in a transparent liquid tank is irradiated with light of a predetermined pattern by laser light scanning or surface exposure using a projector from the lower surface, and the bottom surface of the liquid tank and the model are formed. One layer of the photocurable resin composition in the gap between the table and the table is cured, and then the position of the molding table is lifted upward by one layer to supply the photocurable resin composition under the cured product. A three-dimensional structure may be obtained by repeating the operation of irradiating light and curing. Modeling by such a liquid bath photopolymerization method can be performed using, for example, a commercially available liquid bath photopolymerization 3D printer.

The resin mold molded according to this embodiment is used as a master mold when producing a casting mold. A mold is made by sintering an inorganic material such as gypsum, clay, china clay, or metal. The use of the mold is not particularly limited, and in one embodiment, for example, it may be a mold for molding a dental prosthesis such as a denture base.

As a method for manufacturing the mold, there is a method in which an inorganic material such as gypsum is placed around the resin mold using the resin mold as a prototype, and the inorganic material is sintered by heating in that state. The resin mold disappears by heating during sintering. According to the present embodiment, when the mold is sintered using a resin mold, the sintering residue can be eliminated while suppressing it as much as possible, so the step of removing the sintering residue after the sintering step can be reduced or eliminated. be able to.

In one embodiment, as a method of manufacturing a mold for molding a dental prosthesis such as a denture base, the shape of the patient's oral cavity is measured by three-dimensional measurement, and based on the obtained measurement data, liquid bath photopolymerization is performed. A resin mold is prepared from the photocurable resin composition by a method 3D printer, an inorganic material such as gypsum is placed around the obtained resin mold, and the inorganic material is heated in that state to sinter the resin. A method of obtaining a template by erasing the mold can be mentioned. A dental prosthesis can be made by pouring the material forming the dental prosthesis into the resulting mold and curing.

In addition, various numerical ranges including the above-described compounding amounts and viscosities can be arbitrarily combined with their upper and lower limits, and all combinations thereof are described in this specification as preferred numerical ranges. It is assumed that there is

The present invention will be described in more detail with reference to examples below, but the present invention is not limited to the following examples.

<Measurement/evaluation method>
[viscosity]
The viscosity of the photocurable resin composition was measured at 25° C. with an E-type viscometer.

[Volume shrinkage (molding accuracy)]
A photocurable resin composition was applied to a film thickness of 100 μm and cured under the following UV irradiation conditions. The specific gravity at 20° C. of the resin before and after curing was measured with a pycnometer, and the volume shrinkage was calculated according to the following equation. The smaller the volume shrinkage ratio, the better the molding accuracy.
Volume shrinkage rate (%) = [(specific gravity after curing - specific gravity before curing) / specific gravity after curing] × 100

[Tensile strength, elongation, elastic modulus]
A photocurable resin composition was applied to a film thickness of 100 μm and cured under the following UV irradiation conditions. The strength at break (tensile strength MPa) when the resin after curing is cut into strips with a width of 5 mm is used as a test piece and pulled at a speed of 50 mm / min with an autograph (TENSILON, manufactured by ORIENTEC). Elongation % and elastic modulus MPa were measured.

[UV irradiation conditions]
As a UV irradiation device, a belt conveyor type UV curing device (World Engineering Co., Ltd.) equipped with a UV-LED lamp was used. Irradiation conditions were an integrated illuminance of 4500 mJ/cm ² .

[3D printerability]
Using the photocurable resin composition, a tooth model of 5 cm×5 cm×1 cm was produced under the following 3D printer process conditions. A case where the tooth model was able to be produced was evaluated as "O" (good formability), and a case where the tooth model fell during production or the tooth model was not formed as specified was evaluated as "X" (poor formability).

[Sintering residue]
Using the photocurable resin composition, a three-dimensional object of 5 cm × 5 cm × 1 cm was produced under the following 3D printer process conditions. After placing the obtained three-dimensional object in an electric furnace at 750 ° C. for 1 hour, the sintering residue property was visually evaluated. The case where sintering residue remained was evaluated as "x" (poor sintering residue property).

[3D printer process conditions]
A three-dimensional object having a predetermined shape was produced from the photocurable resin composition using a plane exposure (DLP) stereolithography system (TiTan2 manufactured by Kudo3D). The lamination pitch of stereolithography was 0.1 mm, and the light irradiation time was 60 seconds for the 1st layer, 30 seconds for the 2nd to 10th layers, and 10 seconds for the 10th and subsequent layers. The formed solids were ultrasonically cleaned in isopropanol.

[Examples 1 to 4 and Comparative Examples 1 to 5]
Each component was blended together according to the formulation (parts by mass) shown in Table 1 below, and mixed and stirred with a disperser to obtain photocurable resin compositions of Examples 1 to 4 and Comparative Examples 2 to 6. As Comparative Example 1, a commercial product Press-E-Cast (manufactured by envisionTEC), which is a photocurable resin composition generally used for stereolithography, was prepared. Details of each component in Table 1 are as follows.

(A-1) Isobornyl acrylate: trade name “IBXA”, manufactured by Osaka Organic Chemical Industry Co., Ltd. (A-2) Acryloylmorpholine: trade name “ACMO”, manufactured by KJ Chemicals Co., Ltd. (A-3) Phenoxyethyl acrylate: trade name "New Frontier PHE", manufactured by Daiichi Kogyo Seiyaku Co., Ltd.

(B-1) 10 mol ethylene oxide-modified bisphenol A diacrylate: trade name “New Frontier BPE-10”, Daiichi Kogyo Seiyaku Co., Ltd. (B-2) tris (acryloxyethyl) isocyanurate: trade name “New Frontier TEICA", manufactured by Daiichi Kogyo Seiyaku Co., Ltd. (B-3) bifunctional urethane acrylate: trade name "New Frontier R-1220", manufactured by Daiichi Kogyo Seiyaku Co., Ltd.

(C-1) Crosslinked polymethyl methacrylate particles: trade name “ENEOS Unipowder NMB-0520C”, manufactured by JXTG Energy Co., Ltd., average particle size: 5 μm
(D-1) 1-Hydroxycyclohexylphenyl ketone: trade name "Omnirad 184", IGM Resins B.V. V. (D-2) Phenylbis(2,4,6-trimethylbenzoyl)phosphine oxide manufactured by IGM ResinsB. V. (E-1) organic dye: CI Acid Yellow 42 containing dye: trade name “VARIFAST ORANGE 1225”, manufactured by Orient Chemical Industry Co., Ltd.

The photocurable resin compositions of Examples 1 to 4 and Comparative Examples 1 to 5 were measured and evaluated for viscosity, volumetric shrinkage, tensile strength, elongation, elastic modulus, 3D printerability, and sintering residue. Table 1 shows the results.

As shown in Table 1, the commercially available photocurable resin composition of Comparative Example 1 contains a pigment as a coloring agent, leaving a sintering residue. A mold produced using a mold may result in poor molding due to sintering residue.

On the other hand, with the photocurable resin compositions of Examples 1 to 4, the volume shrinkage rate is small and therefore the molding accuracy is excellent, the 3D printerability is good, and there is no sintering residue, and the Excellent residue resistance. The photocurable resin compositions of Examples 1 to 4 also had sufficiently low viscosities and good flexibility.

On the other hand, the photocurable resin compositions of Comparative Examples 2 and 3 contained less or did not contain crosslinked polymethyl methacrylate particles compared to Examples 1 to 4, and therefore had a large volume shrinkage rate. Poor molding accuracy. The photocurable resin composition of Comparative Example 4 was further inferior in 3D printability, and the test piece was too fragile to measure the tensile strength and the like. Since the photocurable resin composition of Comparative Example 5 did not contain an organic dye, the dental model produced by a 3D printer was significantly different from the design, and was inferior in 3D printerability.

Although several embodiments of the invention have been described above, these embodiments are presented by way of example and are not intended to limit the scope of the invention. These embodiments can be implemented in various other forms, and various omissions, replacements, and modifications can be made without departing from the scope of the invention. These embodiments, their omissions, replacements, modifications, etc., are included in the invention described in the scope of claims and equivalents thereof, as well as being included in the scope and gist of the invention.

Claims (7)

A photocurable resin composition used for molding a resin mold for making a mold by a liquid bath photopolymerization method,
(A) a monofunctional (meth)acrylic monomer, (B) at least one polyfunctional monomer selected from the group consisting of polyfunctional (meth)acrylic acid esters and polyfunctional urethane (meth)acrylates, and (C) crosslinked polymethacryl acid ester particles, (D) a photoinitiator, and (E) an organic dye,
A photocurable resin composition, wherein the content of component (C) is 60 to 140 parts by mass per 100 parts by mass of the total content of component (A) and component (B). 2. The photocurable resin composition according to claim 1, wherein the component (D) contains phenylbis(2,4,6-trimethylbenzoyl)phosphine oxide. The light according to claim 1 or 2, wherein the content of the component (E) is 0.01 to 1 part by mass with respect to 100 parts by mass of the total content of the components (A) and (B). A curable resin composition. The content of the component (D) is 1 to 11 parts by mass per 100 parts by mass of the total content of the component (A) and the component (B), according to any one of claims 1 to 3 A photocurable resin composition as described. The mass ratio of the contents of the (A) component, the (B) component, the (C) component, the (D) component, and the (E) component is (A+B)/C/D/E=41 to The photocurable resin composition according to any one of claims 1 to 4, which ranges from 63/35 to 58/0.4 to 6.5/0.0041 to 0.62. The photocurable resin composition according to any one of claims 1 to 5, which has a viscosity of 20 to 2500 mPa·s at 25°C measured using an E-type viscometer. A resin mold for making a casting mold, which is molded from the photocurable resin composition according to any one of claims 1 to 6 using a liquid bath photopolymerization type 3D printer.