WO2024117203A1 - Photocurable composition, three-dimensional shaped article, dental product, and splint - Google Patents

Abstract

Provided are: a photocurable composition comprising a photopolymerizable component and a photopolymerization initiator, wherein, when a cured layer A1 having a thickness of 50 μm is formed by irradiating the photocurable composition with visible light having a wavelength of 385 nm at an irradiation dose of 11 mJ/cm², a rectangular plate-like shaped article A1 having a length of 40 mm, a width of 10 mm, and a thickness of 1 mm is formed by laminating the cured layer A1 in the thickness direction, and a rectangular plate-like test piece A1 having a length of 40 mm, a width of 10 mm, and a thickness of 1 mm is produced by irradiating the shaped article A1 with ultraviolet rays having a wavelength of 365 nm at an irradiation dose of 10 J/cm², the storage elastic modulus at 37ºC of the test piece A1 is 100-1,500 MPa; a three-dimensional shaped article comprising a cured product of the photocurable composition; a dental product comprising the three-dimensional shaped article; and a splint comprising the three-dimensional shaped article.

Description

Photocurable composition, three-dimensional object, dental product and splint

This disclosure relates to photocurable compositions, three-dimensional objects, dental products, and splints.

In recent years, dental products such as dental prostheses and instruments used in the oral cavity have been studied. For example, from the perspective of the efficiency of molding these dental products, a method of manufacturing three-dimensional objects such as dental products by stereolithography using a 3D printer is known (for example, Patent No. 4160311).

Dental products (for example, dental splints) are primarily used by being worn in the oral cavity, and are subject to wear due to repeated biting caused by teeth grinding or the like.
On the other hand, when the dental prosthesis is placed in the oral cavity, a strong load is applied to the teeth, which may cause pain to the wearer, and may place a large burden on the wearer.

The problem that one embodiment of the present disclosure aims to solve is to provide a photocurable composition that can be used to produce a three-dimensional object that is resistant to wear due to teeth grinding and the like and reduces the burden on the wearer when worn in the oral cavity, as well as to provide such a three-dimensional object, a dental product, and a splint.

Means for solving the above problems include the following aspects.
<1> A photocurable composition comprising a photopolymerizable component and a photopolymerization initiator, the photocurable composition being irradiated with visible light having a wavelength of 385 nm at an irradiation dose of 11 mJ/ ^cm2 to form a cured layer A1 of 50 μm in thickness, the cured layer A1 being laminated in the thickness direction to form a rectangular plate-shaped object A1 of length 40 mm, width 10 mm and thickness 1 mm, and the shaped object A1 being irradiated with ultraviolet light having a wavelength of 365 nm at an irradiation dose of 10 J/ ^cm2 to produce a rectangular plate-shaped test piece A1 of length 40 mm, width 10 mm and thickness 1 mm, the photocurable composition having a storage modulus at 37° C. of 100 MPa or more and 1500 MPa or less.
<2> The photocurable composition according to <1>, wherein the photocurable composition is irradiated with visible light having a wavelength of 385 nm at an irradiation dose of 11 mJ/ ^cm2 to form a cured layer A2 having a thickness of 50 μm, the cured layer A2 is laminated in a thickness direction to form a rectangular plate-shaped object A2 having a length of 50 mm, a width of 40 mm and a thickness of 4.5 mm, the shaped object A2 is irradiated with ultraviolet light having a wavelength of 365 nm at an irradiation dose of 10 J/ ^cm2 , and then a 50 mm × 40 mm surface is double-polished to prepare a rectangular plate-shaped test piece A2 having a length of 50 mm, a width of 40 mm and a thickness of 4.0 mm. In this case, ΔE ^* _ab of the test piece A2 is 10.0 or less.
<3> The photocurable composition according to <1> or <2>, wherein the photopolymerizable component includes: a (meth)acrylic monomer (A) containing two (meth)acryloyloxy groups and having a molecular weight of 1,000 or more; a (meth)acrylic monomer (B) containing two (meth)acryloyloxy groups and having a molecular weight of 170 or more and less than 1,000; and a (meth)acrylic monomer (C) containing one (meth)acryloyloxy group and having an aromatic ring structure.
<4> The photocurable composition according to <3>, wherein the (meth)acrylic monomer (A) further contains a urethane bond.
<5> The photocurable composition according to <3> or <4>, wherein the (meth)acrylic monomer (C) has a molecular weight of 140 to 500.
<6> The photocurable composition according to any one of <3> to <5>, wherein the content of the (meth)acrylic monomer (A) is 5% by mass to 60% by mass based on the total amount of the (meth)acrylic monomer components.
<7> The photocurable composition according to any one of <3> to <6>, wherein the content of the (meth)acrylic monomer (B) is 15% by mass to 80% by mass based on the total amount of the (meth)acrylic monomer components.
<8> The photocurable composition according to any one of <3> to <7>, wherein the content of the (meth)acrylic monomer (C) is 5% by mass to 70% by mass based on the total amount of the (meth)acrylic monomer components.
<9> The photocurable composition according to any one of <3> to <8>, in which the content (mol/g) of methacryloyl groups relative to the total content (mol/g) of acryloyl groups and methacryloyl groups in the photopolymerizable component is 0% to 90%.
<10> The photocurable composition according to any one of <1> to <9>, wherein the photopolymerization initiator contains an acylphosphine oxide compound.
<11> The photocurable composition according to any one of <1> to <10>, which has a viscosity of 5 mPa·s to 6,000 mPa·s as measured with an E-type viscometer at 25° C. and 50 rpm.
<12> The photocurable composition according to any one of <1> to <11>, which is a photocurable composition for stereolithography.
<13> The photocurable composition according to any one of <1> to <12>, which is used for producing a splint by stereolithography.
<14> A three-dimensional object comprising a cured product of the photocurable composition according to any one of <1> to <13>.
<15> A dental product comprising the three-dimensional object according to <14>.
<16> A splint including the three-dimensional object according to <14>.

According to one embodiment of the present disclosure, it is possible to provide a photocurable composition capable of producing a three-dimensional object that is resistant to wear due to teeth grinding and the like and reduces the burden on the wearer when worn in the oral cavity, as well as such a three-dimensional object, a dental product, and a splint.

In the present disclosure, a numerical range expressed using "to" means a range that includes the numerical values before and after "to" as the lower and upper limits.
In the present disclosure, the term "process" refers not only to an independent process, but also to a process that cannot be clearly distinguished from other processes, as long as the intended purpose of the process is achieved.
In the present disclosure, when a plurality of substances corresponding to each component are present in the composition, the amount of each component contained in the composition means the total amount of the plurality of substances present in the composition, unless otherwise specified.
In the numerical ranges described in the present disclosure in stages, the upper or lower limit value described in one numerical range may be replaced with the upper or lower limit value of another numerical range described in stages. In addition, in the numerical ranges described in the present disclosure, the upper or lower limit value of the numerical range may be replaced with a value shown in the examples.
In the present disclosure, the term "light" is a concept that encompasses active energy rays such as ultraviolet light and visible light.

In this disclosure, "(meth)acrylate" means acrylate or methacrylate, "(meth)acryloyl" means acryloyl or methacryloyl, and "(meth)acrylic" means acrylic or methacrylic.

<Photocurable composition>
The photocurable composition of the present disclosure is a photocurable composition containing a photopolymerizable component and a photopolymerization initiator, and the photocurable composition is irradiated with visible light having a wavelength of 385 nm at an irradiation dose of 11 mJ/cm2 to form a cured layer A1 of a thickness of 50 μm, and the cured layer A1 is laminated in the thickness direction to form a rectangular plate-shaped object A1 of length 40 mm, width 10 mm, and thickness 1 mm. The object A1 is irradiated with ^ultraviolet light having a wavelength of 365 nm at an irradiation dose of 10 J/ ^cm2 to produce a rectangular plate-shaped test piece A1 of length 40 mm, width 10 mm, and thickness 1 mm. The storage modulus of the test piece A1 at 37° C. is 100 MPa or more and 1500 MPa or less.

The photocurable composition disclosed herein, by containing the above-mentioned components, can produce a three-dimensional object that is resistant to wear due to teeth grinding and the like, and reduces the burden on the wearer when worn in the oral cavity.

As an example of stereolithography, liquid tank type stereolithography (that is, stereolithography using a liquid tank) is known.
In liquid tank type stereolithography, a portion of the photocurable composition (i.e., an uncured photocurable composition in a liquid state; the same applies below) contained in a liquid tank is cured by irradiation with light to form a cured layer, and this operation is repeated to stack the cured layers, thereby obtaining a three-dimensional object. Liquid tank type stereolithography differs from inkjet type stereolithography in that a liquid tank is used.
The liquid vat type stereolithography is broadly divided into DLP (Digital Light Processing) type stereolithography and SLA (Stereolithography) type stereolithography. In the DLP type, a light beam is irradiated onto a photocurable composition in a liquid vat in a planar manner. In the SLA type, a laser beam is scanned onto a photocurable composition in a liquid vat.

In an example of DLP type stereolithography, for example,
a build table that is vertically movable;
a tray (i.e., a liquid tank) that is disposed below the build table (on the side in the direction of gravity; the same applies below), includes a light-transmitting portion, and contains a photocurable composition;
a light source (e.g., an LED light source) disposed below the tray for irradiating the photocurable composition in the tray with planar light through a light-transmitting portion of the tray;
In this case, a 3D printer equipped with the above function (e.g., "Cara Print 4.0" manufactured by Kulzer, "Max UV" manufactured by Asiga, etc.) is used.
In this example, first, a gap of one layer is provided between the build table and the tray, and the gap is filled with the photocurable composition. Next, the photocurable composition filled in the gap is irradiated with planar light from below through the light-transmitting portion of the tray, and the area irradiated with light is cured to form a first cured layer. Next, the gap between the build table and the tray is widened by the next layer, and the resulting space is filled with the photocurable composition. Next, the photocurable composition filled in the space is irradiated with light in the same manner as the curing of the first layer, and a second cured layer is formed. By repeating the above operations, the cured layers are stacked to produce a three-dimensional object. In this example, the three-dimensional object produced may be further cured by further irradiating the three-dimensional object with light.

<Storage modulus at 37° C.>
The photocurable composition of the present disclosure is irradiated with visible light having a wavelength of 385 nm at an irradiation dose of 11 mJ/ ^cm2 to form a cured layer A1 of a thickness of 50 μm, and the cured layer A1 is laminated in the thickness direction to form a rectangular plate-shaped object A1 of length 40 mm, width 10 mm and thickness 1 mm. The shaped object A1 is irradiated with ultraviolet light having a wavelength of 365 nm at an irradiation dose of 10 J/ ^cm2 to produce a rectangular plate-shaped test piece A1 of length 40 mm, width 10 mm and thickness 1 mm. The storage modulus of the test piece A1 at 37° C. is 100 MPa or more and 1500 MPa or less.

The storage modulus at 37°C is preferably 150 MPa or more, more preferably 200 MPa or more, even more preferably 300 MPa or more, and particularly preferably 400 MPa or more, from the viewpoint of resistance to wear due to teeth grinding, etc.

The storage modulus at 37°C is preferably 1400 MPa or less, more preferably 1200 MPa or less, even more preferably 1000 MPa or less, and particularly preferably 800 MPa or less, from the viewpoint of reducing the burden on the wearer when the device is worn in the oral cavity.

(Test Piece A1)
The test piece A1 is a rectangular plate-shaped test piece having a length of 40 mm, a width of 10 mm, and a thickness of 1 mm.
Test piece A1 was produced by photopolymerization under the following conditions: the photocurable composition of the present disclosure was irradiated with visible light having a wavelength of 385 nm at an irradiation dose of 11 mJ/ ^cm2 to form a cured layer A1 with a thickness of 50 μm, the cured layer A1 was then stacked in the thickness direction to form a rectangular plate-shaped object A1 with a length of 40 mm, a width of 10 mm and a thickness of 1 mm, and the object A1 was then irradiated with ultraviolet light having a wavelength of 365 nm at an irradiation dose of 10 J/ ^cm2 .
The test piece A1 can be produced, for example, according to an example of the DLP type stereolithography described above.
The test piece A1 may be produced using a DLP type 3D printer, "Cara Print 4.0" manufactured by Kulzer.

(Measurement of storage modulus)
In the present disclosure, the storage modulus at 37° C. is, in particular, the storage modulus at 37° C. measured by dynamic viscoelasticity measurement under conditions of a temperature rise range of 25° C. to 300° C. at a temperature rise rate of 3° C./min at a measurement frequency of 1 Hz.
As a dynamic viscoelasticity measuring device, a dynamic viscoelasticity measuring device "DMA7100" manufactured by Hitachi High-Tech Corporation may be used.

<ΔE ^* _ab >
In the photocurable composition of the present disclosure, the photocurable composition is irradiated with visible light having a wavelength of 385 nm at an irradiation dose of 11 mJ/ ^cm2 to form a cured layer A2 of a thickness of 50 μm, and the cured layer A2 is laminated in the thickness direction to form a rectangular plate-shaped object A2 of a length of 50 mm, a width of 40 mm, and a thickness of 4.5 mm. The object A2 is then irradiated with ultraviolet light having a wavelength of 365 nm at an irradiation dose of 10 J/ ^cm2 , and the 50 mm x 40 mm surfaces are then double-polished to produce a rectangular plate-shaped test piece A2 of a length of 50 mm, a width of 40 mm, and a thickness of 4.0 mm. In this case, it is preferable that the ΔE ^* _ab of test piece A2 is 10.0 or less.

From the viewpoint of transparency of the resulting cured product, ΔE ^* _ab is more preferably 6.0 or less, further preferably 5.5 or less, particularly preferably 5.0 or less, and most preferably 4.5 MPa or less.

There is no particular restriction on the lower limit of ΔE ^* _ab , and it may be more than 0, 0.1 or more, or 1.0 or more.
When the requirement for transparency of the cured product is low, the lower limit of ΔE ^* _ab may be more than 6.0.

(Test Piece A2)
The test piece A2 is a rectangular plate-shaped test piece having a length of 50 mm, a width of 40 mm, and a thickness of 4.0 mm.
Test piece A2 was produced by irradiating the photocurable composition of the present disclosure with visible light having a wavelength of 385 nm at an irradiation dose of 11 mJ/ ^cm2 to form a cured layer A2 with a thickness of 50 μm, stacking the cured layer A2 in the thickness direction to form a rectangular plate-shaped object A2 with a length of 50 mm, a width of 40 mm, and a thickness of 4.5 mm, irradiating object A2 with ultraviolet light having a wavelength of 365 nm at an irradiation dose of 10 J/ ^cm2 , and then polishing both sides of the 50 mm x 40 mm surfaces.
The test piece A2 can be produced, for example, according to an example of the DLP type stereolithography described above.
The test piece A2 may be produced using a DLP type 3D printer, "Cara Print 4.0" manufactured by Kulzer.

(Measurement of ΔE ^* _ab )
In this disclosure, ΔE ^* _ab is measured by a color difference meter in transmission mode for the L ^* a ^* b ^* of a 50mm x 40mm surface, using the attached STANDARD WHITE PLATE (SCI X: 94.25, Y: 99.44, Z: 106.37) as a reference. ΔE*ab is calculated by the formula ΔE ^* ab = (ΔL2 ⁺ _Δa2 + Δb2) 1/2, using the L ^* a ^* b ^* of a 50mm x 40mm x 4.0mm transparent PMMA plate (Asahi Manufacturing, L* = 96.98, a ^* = -0.24, b ^* = 0.05; color values based on "SCI X: 94.25, Y ^: 99.44, Z: 106.37" as a reference _color ).
As the color difference meter, SD3000 manufactured by Nippon Denshoku Industries Co., Ltd. may be used.

<Photopolymerizable component>
The photocurable compositions of the present disclosure contain at least one photopolymerizable component.
The photopolymerizable component includes a compound containing an ethylenic double bond.
Examples of the compound containing an ethylenic double bond include (meth)acrylic monomers, styrene, styrene derivatives, and (meth)acrylonitrile.

As the photopolymerizable component, the photopolymerizable components described in paragraphs 0030 to 0059 of WO 2019/189652 may be used.

The content of the photopolymerizable component in the total amount of the photocurable composition of the present disclosure is preferably 60% by mass or more, more preferably 80% by mass or more, and even more preferably 90% by mass or more.

The photopolymerizable component preferably contains at least one (meth)acrylic monomer.
Here, the (meth)acrylic monomer means a monomer having one or more (meth)acryloyl groups. As the (meth)acrylic monomer, a monomer having one or more (meth)acryloyloxy groups is preferable.

In this disclosure, all (meth)acrylic monomers contained in the photocurable composition may be referred to as "(meth)acrylic monomer components," and the total content of all (meth)acrylic monomers contained in the photocurable composition of this disclosure may be referred to as "total amount of (meth)acrylic monomer components."

From the viewpoint of being resistant to wear due to teeth grinding, etc., and reducing the burden on the wearer when worn in the oral cavity, the total amount of (meth)acrylic monomer components relative to the total amount of photopolymerizable components in the photocurable composition of the present disclosure is preferably 80% by mass or more, more preferably 90% by mass or more, and even more preferably 95% by mass or more.

From the viewpoint of being resistant to wear due to teeth grinding and the like, and reducing the burden on the wearer when worn in the oral cavity, the total amount of (meth)acrylic monomer components relative to the total amount of the photocurable composition of the present disclosure is preferably 60% by mass or more, more preferably 80% by mass or more, and even more preferably 90% by mass or more.

The (meth)acrylic monomer constituting the (meth)acrylic monomer component is not particularly limited as long as it is a monomer having one or more (meth)acryloyl groups.
The (meth)acrylic monomer is
It may be a mono(meth)acrylic monomer having one (meth)acryloyl group (hereinafter also referred to as a "monofunctional (meth)acrylic monomer");
It may be a di(meth)acrylic monomer having two (meth)acryloyl groups (hereinafter also referred to as a "bifunctional (meth)acrylic monomer");
It may be a poly(meth)acrylic monomer having three or more (meth)acryloyl groups (hereinafter also referred to as a "polyfunctional (meth)acrylic monomer").

The mono(meth)acrylic monomer is preferably a mono(meth)acrylic monomer having one (meth)acryloyloxy group.
The di(meth)acrylic monomer is preferably a di(meth)acrylic monomer having two (meth)acryloyloxy groups.
The tri(meth)acrylic monomer is preferably a poly(meth)acrylic monomer having three or more (meth)acryloyloxy groups.

The photopolymerizable component is
A (meth)acrylic monomer (A) containing two (meth)acryloyloxy groups and having a molecular weight of 1,000 or more;
(B) a (meth)acrylic monomer containing two (meth)acryloyloxy groups and having a molecular weight of 170 or more and less than 1,000; and
(C) a (meth)acrylic monomer containing one (meth)acryloyloxy group and containing an aromatic ring structure
It is preferable to include at least one of the following:

The photopolymerizable component is
A (meth)acrylic monomer (A) containing two (meth)acryloyloxy groups and having a molecular weight of 1000 or more;
a (meth)acrylic monomer (B) containing two (meth)acryloyloxy groups and having a molecular weight of 170 or more and less than 1,000;
A (meth)acrylic monomer (C) containing one (meth)acryloyloxy group and containing an aromatic ring structure;
It is more preferred that the composition comprises:
When these conditions are satisfied, the storage modulus at 37° C. can be easily adjusted to fall within the above range.

((Meth)acrylic monomer (A))
The (meth)acrylic monomer (A) contains two (meth)acryloyloxy groups and has a molecular weight of 1,000 or more.
When the photopolymerizable component contains the (meth)acrylic monomer (A), the softness of the obtained cured product can be improved (i.e., the storage modulus at 37°C can be adjusted to be lowered), and the reactivity is also excellent.

The molecular weight of the (meth)acrylic monomer (A) is 1,000 or more, preferably 1,300 or more, more preferably 1,700 or more, and even more preferably 2,100 or more.
There is no particular upper limit to the molecular weight of the (meth)acrylic monomer (A).
The molecular weight of the (meth)acrylic monomer (A) may be 20,000 or less, preferably 10,000 or less, more preferably 8,000 or less, and even more preferably 6,000 or less.
The molecular weight of the (meth)acrylic monomer (A) is preferably 1,000 or more and 15,000 or less, and more preferably 1,000 or more and 10,000 or less.

The (meth)acrylic monomer (A) preferably contains a urethane bond.
That is, the (meth)acrylic monomer (A) is preferably a urethane diacrylate monomer.
This provides the resulting cured product with excellent toughness.

The (meth)acrylic monomer (A) is preferably a compound represented by the following general formula (A1):

In formula (A1), R ₁ 's are each independently a divalent organic group, R ₂ 's are each independently a divalent hydrocarbon group which may have a substituent, R ₃ 's are each independently a hydrogen atom or a methyl group, X is a divalent organic group, and n is an integer of 0 to 10. When there are a plurality of R _1's , R _2's , and R ₃ 's, they may be the same or different, and when there are a plurality of X's, they may be the same or different.

In formula (A1), examples of R ₁ include divalent organic groups containing one or more bonds selected from the group consisting of divalent hydrocarbon groups, ether bonds, and ester bonds.
The divalent hydrocarbon group represented by R ₁ may be, for example, a divalent chain hydrocarbon group or a divalent hydrocarbon group containing a ring structure (aromatic ring structure, alicyclic structure).
When the divalent organic group represented by R ₁ contains an ether bond, the number of the ether bonds is preferably 1 to 30, more preferably 1 to 20, and further preferably 1 to 15.
When the divalent organic group represented by R ₁ contains an ester bond, the number of the ester bonds is preferably 1 to 12, more preferably 1 to 8, and further preferably 1 to 6.
In formula (A1), R ₁ may have, for example, 2 to 60 carbon atoms, preferably 2 to 40 carbon atoms, and more preferably 2 to 30 carbon atoms.

In formula (A1), R ₁ is preferably a group represented by the following general formula (A1-R ₁ ).

In general formula (A1-R ₁ ), R _1A is a divalent hydrocarbon group which may have a substituent, R _1B is a methylene group (-CH ₂ -) or a carbonyl group (-C(=O)-), R _1C is a divalent hydrocarbon group, and m is an integer of 0 to 10. When a plurality of R _1B and R _1C are present, they may be the same or different. * indicates a bonding position.

The divalent hydrocarbon group which may have a substituent as R _1A in general formula (A1-R ₁ ) is, for example, a divalent chain hydrocarbon group or a divalent hydrocarbon group containing a ring structure, preferably a divalent chain hydrocarbon group. The ring structure contained in the divalent hydrocarbon group may be an aromatic structure or an alicyclic structure.
The divalent chain hydrocarbon group represented by R _1A may be branched and may be saturated or unsaturated.
The divalent chain hydrocarbon group represented by R _1A preferably has 2 to 20 carbon atoms, more preferably 2 to 15 carbon atoms, and even more preferably 2 to 10 carbon atoms.
The substituent that the divalent chain hydrocarbon group represented by R _1A may have is, for example, an alkoxy group having 2 to 10 carbon atoms or an aryloxy group having 6 to 20 carbon atoms, preferably an aryloxy group. Examples of the aryloxy group include a phenoxy group and a naphthyloxy group, and the phenoxy group is preferred.
The divalent hydrocarbon group containing an aromatic structure represented by R _1A is preferably a divalent hydrocarbon group having an aromatic structure containing 6 to 25 carbon atoms (more preferably 6 to 20 carbon atoms, and even more preferably 6 to 15 carbon atoms). Examples of the substituent that the divalent hydrocarbon group containing an aromatic structure may have include a linear or branched alkyl group having 1 to 6 carbon atoms.
The divalent hydrocarbon group containing an alicyclic structure represented by R _1A is preferably a divalent hydrocarbon group having an alicyclic structure having 3 to 20 carbon atoms (more preferably 6 to 12 carbon atoms, and even more preferably 6 to 8 carbon atoms). Examples of the substituent that the divalent hydrocarbon group containing an alicyclic structure may have include a linear or branched alkyl group having 1 to 6 carbon atoms.

Examples of the divalent hydrocarbon group represented by R _1C in general formula (A1-R ₁ ) include divalent chain hydrocarbon groups and divalent hydrocarbon groups containing a ring structure (aromatic structure or alicyclic structure), with a divalent chain hydrocarbon group being preferred.
The divalent chain hydrocarbon group represented by R _1C preferably has 1 to 30 carbon atoms, more preferably 1 to 20 carbon atoms, and even more preferably 1 to 10 carbon atoms.
The divalent hydrocarbon group having an aromatic structure represented by R _1C is preferably a divalent hydrocarbon group having an aromatic structure having 6 to 25 carbon atoms (more preferably 6 to 20 carbon atoms, and even more preferably 6 to 15 carbon atoms).
The divalent hydrocarbon group containing an alicyclic structure as R _1C is preferably a divalent hydrocarbon group having an alicyclic structure having 3 to 20 carbon atoms (more preferably 6 to 12 carbon atoms, and even more preferably 6 to 8 carbon atoms).

In formula (A1-R ₁ ), m is an integer of 0 to 10, preferably 0 to 8, and more preferably 0 to 6.

In general formula (A1-R ₁ ), the * on the left side (i.e., the bonding position from R _1A ) preferably bonds to the oxygen atom on the left side of R ₁ in general formula (A1), and the * on the right side (i.e., the bonding position from R _1C ) preferably bonds to the oxygen atom on the right side of R ₁ in general formula (A1).

In formula (A1), the divalent hydrocarbon group represented by R ₂ is, for example, a divalent chain hydrocarbon group or a divalent hydrocarbon group containing a ring structure.
The divalent chain hydrocarbon group represented by _R2 preferably has 1 to 25 carbon atoms, more preferably has 1 to 20 carbon atoms, and even more preferably has 2 to 15 carbon atoms.
The divalent hydrocarbon group containing a ring structure represented by _R2 may contain an aromatic structure or an alicyclic structure.
The divalent hydrocarbon group containing an aromatic structure represented by _R2 preferably has 6 to 25 carbon atoms, more preferably 6 to 20 carbon atoms, and even more preferably 6 to 15 carbon atoms.
The divalent hydrocarbon group containing an alicyclic structure represented by _R2 preferably has 3 to 20 carbon atoms, more preferably 6 to 15 carbon atoms, and even more preferably 6 to 10 carbon atoms.

Specifically, the divalent hydrocarbon group represented by R ₂ is preferably a divalent hydrocarbon group represented by a structure selected from the following general formulae (A1-R ₂ -1) to (A1-R ₂ -13).

In the general formulae (A1-R ₂ -1) to (A1-R ₂ -13), * indicates the bonding position.

In formula (A1), X is a divalent organic group, and is preferably a divalent organic group containing one or more bonds selected from the group consisting of ether bonds and ester bonds.
When the divalent organic group represented by X contains an ether bond, the number of the ether bonds is preferably 1 to 100, more preferably 2 to 90, and further preferably 4 to 80.
When the divalent organic group represented by X contains an ester bond, the number of ester bonds is preferably 1 to 100, more preferably 2 to 90, and further preferably 4 to 80.
The divalent organic group represented by X preferably has 2 to 500 carbon atoms, more preferably 2 to 400 carbon atoms, and even more preferably 2 to 300 carbon atoms.

In formula (A1), X is preferably a group represented by the following general formula (A1-X):

In general formula (A1-X), R _XA is a divalent hydrocarbon group, R _XB is a methylene group (-CH ₂ -) or a carbonyl group (-C(=O)-), R _XC is a divalent hydrocarbon group, and k is an integer of 0 to 100. When a plurality of R _XB and R _XC are present, they may be the same or different. * indicates a bonding position.

The divalent hydrocarbon group represented by R _XA in general formula (A1-X) is, for example, a divalent chain hydrocarbon group or a divalent hydrocarbon group containing a ring structure, and is preferably a divalent chain hydrocarbon group. The ring structure contained in the divalent hydrocarbon group may be an aromatic structure or an alicyclic structure.
The divalent chain hydrocarbon group represented by R 1 _XA may be branched and may be saturated or unsaturated.
The divalent chain hydrocarbon group represented by R 1 _XA preferably has 2 to 20 carbon atoms, more preferably 2 to 15 carbon atoms, and even more preferably 2 to 10 carbon atoms.
The divalent hydrocarbon group containing an aromatic structure as R _XA is preferably a divalent hydrocarbon group having an aromatic structure having 6 to 25 carbon atoms (more preferably 6 to 20 carbon atoms, and even more preferably 6 to 15 carbon atoms).
The divalent hydrocarbon group containing an alicyclic structure as R _XA is preferably a divalent hydrocarbon group having an alicyclic structure having 3 to 20 carbon atoms (more preferably 6 to 12 carbon atoms, and even more preferably 6 to 8 carbon atoms).

Examples of the divalent hydrocarbon group represented by R 3 _XC in general formula (A1-X) include divalent chain hydrocarbon groups and divalent hydrocarbon groups containing a ring structure, with a divalent chain hydrocarbon group being preferred.
The divalent chain hydrocarbon group represented by R 3 _XC preferably has 1 to 30 carbon atoms, more preferably 1 to 20 carbon atoms, and even more preferably 1 to 10 carbon atoms.
The divalent hydrocarbon group containing an aromatic structure as R _XC is preferably a divalent hydrocarbon group having an aromatic structure having 6 to 25 carbon atoms (more preferably 6 to 20 carbon atoms, and even more preferably 6 to 15 carbon atoms).
The divalent hydrocarbon group containing an alicyclic structure as R _{3 XC} is preferably a divalent hydrocarbon group having an alicyclic structure having 3 to 20 carbon atoms (more preferably 6 to 12 carbon atoms, and even more preferably 6 to 8 carbon atoms).

In general formula (A1-X), k is 0 to 100, preferably 2 to 90, and more preferably 4 to 80.

The content of (meth)acrylic monomer (A) is preferably 5% by mass to 60% by mass, more preferably 10% by mass to 50% by mass, and even more preferably 15% by mass to 45% by mass, based on the total amount of (meth)acrylic monomer components.

((Meth)acrylic monomer (B))
The (meth)acrylic monomer (B) contains two (meth)acryloyloxy groups and has a molecular weight of 170 or more and less than 1,000.
When the photopolymerizable component contains the (meth)acrylic monomer (B), the hardness of the obtained cured product can be improved (i.e., the storage modulus at 37°C can be adjusted to be increased), and the reactivity is also excellent.

The (meth)acrylic monomer (B) preferably contains a cyclic structure.
The number of rings in the cyclic structure contained in the (meth)acrylic monomer (B) may be only one, or may be two or more.
The cyclic structure contained in the (meth)acrylic monomer (B) may be either an aromatic ring structure or an alicyclic structure, or both, but preferably contains an aromatic ring structure.
The cyclic structure contained in the (meth)acrylic monomer (B) is particularly preferably a bisphenol A structure.
It is particularly preferable that the (meth)acrylic monomer (B) contains two urethane bonds, and for example, a compound represented by the following general formula (B1) (hereinafter also referred to as "(meth)acrylic monomer (B1)") is preferable.

In formula (B1), _R1 is independently a divalent organic group, _R2 is independently a divalent hydrocarbon group which may have a substituent, and _R3 is independently a hydrogen atom or a methyl group. A plurality of _R1s and _R3s may be the same or different.

Examples of R ₁ include divalent organic groups containing one or more bonds selected from the group consisting of divalent hydrocarbon groups and ether bonds.
The divalent hydrocarbon group represented by R ₁ is preferably, for example, a divalent chain hydrocarbon group or a divalent hydrocarbon group containing a ring structure (aromatic ring structure, alicyclic structure).
When the divalent organic group represented by R ₁ contains an ether bond, the number of the ether bonds is more preferably 1 to 2.

In formula (B1), R ₁ may have, for example, 2 to 30 carbon atoms, preferably 2 to 20 carbon atoms, and more preferably 2 to 10 carbon atoms.
R ₁ is preferably an alkylene group having 2 to 6 carbon atoms which may have a substituent, and the substituent is preferably an aryloxy group (for example, a phenoxy group).
When the photocurable composition of the present disclosure contains the (meth)acrylic monomer (B1) as the (meth)acrylic monomer (B), the (meth)acrylic monomer (B) may further contain a (meth)acrylic monomer (B2) having neither a urethane bond nor a ring structure.

The molecular weight of the (meth)acrylic monomer (B) is 170 or more and less than 1,000, preferably 200 or more and 800 or less, and more preferably 300 or more and 700 or less.

(Meth)acrylic monomers (B) include ethoxylated bisphenol A diacrylate, urethane di(meth)acrylate, tetraethylene glycol diacrylate, nonanepropylene glycol dimethacrylate, etc. Among these, (meth)acrylic monomers (B2) include tetraethylene glycol diacrylate, nonanepropylene glycol dimethacrylate, propoxylated (2) neopentyl glycol diacrylate, etc.

The content of the (meth)acrylic monomer (B) is preferably 15% by mass to 80% by mass, more preferably 20% by mass to 70% by mass, and even more preferably 25% by mass to 60% by mass, based on the total amount of the (meth)acrylic monomer components.
Among these, when the (meth)acrylic monomer (B1) and the (meth)acrylic monomer (B2) are contained in the photocurable composition of the present disclosure, the content of the (meth)acrylic monomer (B1) is preferably 10% by mass to 60% by mass, more preferably 15% by mass to 50% by mass, and even more preferably 20% by mass to 45% by mass, relative to the total amount of the (meth)acrylic monomer components, and the content of the (meth)acrylic monomer (B2) is preferably 0.1% by mass to 20% by mass, more preferably 1% by mass to 20% by mass, and even more preferably 1.5% by mass to 10% by mass, relative to the total amount of the (meth)acrylic monomer components.

((Meth)acrylic monomer (C))
The (meth)acrylic monomer (C) contains one (meth)acryloyloxy group and contains an aromatic ring structure.
By including the (meth)acrylic monomer (C) in the photopolymerizable component, the softness of the obtained cured product can be improved (i.e., the storage modulus at 37° C. can be adjusted to be lower), and excessive reactivity can be suppressed. The (meth)acrylic monomer (C) may also be used as a diluent.

The (meth)acrylic monomer (C) has an aromatic ring structure.
The number of aromatic ring structures contained in the (meth)acrylic monomer (C) may be only one, or may be two or more.
The aromatic ring structure contained in the (meth)acrylic monomer (C) is particularly preferably a benzene ring.

The molecular weight of the (meth)acrylic monomer (C) is preferably 140-500, more preferably 150-400, and even more preferably 170-300.
The (meth)acrylic monomer (C) may be, for example, a compound represented by the following formula (C1):

In formula (C1), R ₁ is a monovalent organic group having an aromatic ring, and R ₂ is a hydrogen atom or a methyl group.

In formula (C1), R ₁ preferably has 6 to 30 carbon atoms, and more preferably has 6 to 20 carbon atoms.

The monovalent organic group represented by R ₁ in formula (C1) may have one or more aromatic rings, and preferably has one or two aromatic rings.
The aromatic ring contained in the monovalent organic group represented by R ₁ in formula (C1) may be a monocyclic ring or a polycyclic ring.
Examples of the monocyclic aromatic ring include a phenyl structure (phenyl group, phenylene group). The monocyclic aromatic ring may have a substituent, and examples of the substituent include an alkyl group, an aryloxy group (e.g., a phenoxy group), an arylalkylene group, and an aryl group.
Examples of the polycyclic aromatic ring include a naphthyl structure (a naphthyl group, a naphthylene group). The polycyclic aromatic ring may have a substituent, and examples of the substituent include an alkyl group, an aryloxy group (such as a phenoxy group), an arylalkylene group, and an aryl group.

R ₁ is preferably a monovalent organic group represented by a structure selected from the following general formulae (C1-R ₁ -1) to (C1-R ₁ -7).

In the general formulae (C1-R ₁ -1) to (C1-R ₁ -7), * indicates the bonding position.
In general formula (C1-R ₁ -7), R _1A represents an alkyl group having 1 to 10 carbon atoms.

Examples of (meth)acrylic monomers (C) include benzyl methacrylate, phenoxyethyl methacrylate, phenoxyethyl acrylate, m-phenoxybenzyl acrylate, 2-(o-phenylphenoxy)ethyl acrylate, 2-hydroxy-3-phenoxypropyl acrylate, etc.

The content of the (meth)acrylic monomer (C) is preferably 5% by mass to 70% by mass based on the total amount of the (meth)acrylic monomer components.
When the content of the (meth)acrylic monomer (C) is 70 mass% or less based on the total amount of the (meth)acrylic monomer components, the reactivity is excellent, and thus the moldability is excellent and an increase in viscosity can be suppressed.
From the above viewpoints, the content of the (meth)acrylic monomer (C) is more preferably 60% by mass or less, and even more preferably 50% by mass or less, based on the total amount of the (meth)acrylic monomer components.
When the content of the (meth)acrylic monomer (C) is 5 mass % or more based on the total amount of the (meth)acrylic monomer components, excessive reactivity can be suppressed.
From the above viewpoint, the content of the (meth)acrylic monomer (C) is more preferably 10 mass % or more based on the total amount of the (meth)acrylic monomer components.

(Other (meth)acrylic monomers)
The photopolymerizable component may contain a (meth)acrylic monomer other than the above-mentioned (meth)acrylic monomer (A), (meth)acrylic monomer (B), and (meth)acrylic monomer (C).

The molecular weight of the other (meth)acrylic monomer is preferably 80 to 600, more preferably 100 to 400, and even more preferably 140 to 250.

As the other (meth)acrylic monomer, a (meth)acrylic monomer having one (meth)acryloyloxy group is preferred.
As the other (meth)acrylic monomer, a (meth)acrylic monomer having no aromatic ring structure is also preferred.

As the other (meth)acrylic monomer, a (meth)acrylic monomer (D) containing one (meth)acryloyloxy group and having no aromatic ring structure is more preferable.
When the photopolymerizable component contains the (meth)acrylic monomer (D), an increase in the viscosity of the photocurable composition can be suppressed, and the viscosity of the photocurable composition can be easily adjusted.
In this case, by using the (meth)acrylic monomer (C) and the (meth)acrylic monomer (D) in combination, the effect of improving the softness of the resulting cured product can be obtained.

The molecular weight of the (meth)acrylic monomer (D) is preferably 120 to 400, more preferably 1300 to 350, and even more preferably 140 to 300.

The content of the (meth)acrylic monomer (D) is preferably 0% by mass to 30% by mass, more preferably 1% by mass to 30% by mass, more preferably 5% by mass to 25% by mass, and still more preferably 10% by mass to 23% by mass, based on the total amount of the (meth)acrylic monomer components.
When the content of the (meth)acrylic monomer (D) is 30% by mass or less (preferably 25% by mass or less) based on the total amount of the (meth)acrylic monomer components, the reactivity is excellent. This makes it possible to provide excellent moldability and suppress an increase in viscosity.
When the content of the (meth)acrylic monomer (D) is 5% by mass or more based on the total amount of the (meth)acrylic monomer components, an increase in viscosity can be suppressed and excessive reactivity can be suppressed.

Examples of (meth)acrylic monomers (D) include tertiary butyl (meth)acrylate, cyclohexyl (meth)acrylate, isobornyl (meth)acrylate, and tetrahydrofurfuryl (meth)acrylate.

In the photocurable composition of the present disclosure, a higher content of (meth)acrylic monomer (A) and (meth)acrylic monomer (B) contributes to improving reactivity and improving formability, while a lower content contributes to adjusting the viscosity lower. From this perspective, the total content of (meth)acrylic monomer (A) and (meth)acrylic monomer (B) is preferably 20% by mass to 95% by mass with respect to the total amount of (meth)acrylic monomer components (i.e., the total content of all (meth)acrylic monomers contained in the photocurable composition).

In the photocurable composition of the present disclosure, the total content of the (meth)acrylic monomer (A), the (meth)acrylic monomer (B), and the (meth)acrylic monomer (C) is preferably 50 mass% or more, more preferably 65 mass% or more, even more preferably 80 mass% or more, and particularly preferably 90 mass% or more, based on the total amount of the (meth)acrylic monomer components (i.e., the total content of all the (meth)acrylic monomers contained in the photocurable composition).
The total content may be 100% by mass or less than 100% by mass (for example, 95% by mass or less, 90% by mass or less, etc.).

In the photocurable composition of the present disclosure, the total content of the (meth)acrylic monomer (A), the (meth)acrylic monomer (B), the (meth)acrylic monomer (C) and the (meth)acrylic monomer (D) is preferably 60 mass% or more, more preferably 80 mass% or more, even more preferably 90 mass% or more, and particularly preferably 95 mass% or more, based on the total amount of the (meth)acrylic monomer components (i.e., the total content of all the (meth)acrylic monomers contained in the photocurable composition).
The total content may be 100% by mass or less than 100% by mass (for example, 95% by mass or less, 90% by mass or less, etc.).

In the photocurable composition of the present disclosure, the total content of the (meth)acrylic monomer (A), the (meth)acrylic monomer (B), the (meth)acrylic monomer (C) and the (meth)acrylic monomer (D) is preferably 60 mass% or more, more preferably 80 mass% or more, even more preferably 90 mass% or more, and particularly preferably 95 mass% or more, based on the total amount of the photopolymerizable components.
The total content may be 100% by mass or less than 100% by mass (for example, 95% by mass or less, 90% by mass or less, etc.).

In the photopolymerizable component, the content (mol/g) of methacryloyl groups relative to the total content (mol/g) of acryloyl groups and methacryloyl groups is preferably 0% to 90%.
When the content (mol/g) of methacryloyl groups relative to the total content (mol/g) of acryloyl groups and methacryloyl groups is 90% or less, excellent reactivity and improved moldability are achieved.
From the above viewpoint, the content (mol/g) of methacryloyl groups relative to the total content (mol/g) of acryloyl groups and methacryloyl groups is more preferably 70% or less, even more preferably 50% or less, and particularly preferably 40% or less.
When the content (mol/g) of methacryloyl groups relative to the total content (mol/g) of acryloyl groups and methacryloyl groups is 0% or more (particularly, more than 0%), the hardness of the obtained cured product is excellent.
From the above viewpoints, the content (mol/g) of methacryloyl groups relative to the total content (mol/g) of acryloyl groups and methacryloyl groups is more preferably 3% or more, even more preferably 5% or more, and particularly preferably 10% or more.

<Photopolymerization initiator>
The photocurable composition of the present disclosure contains a photopolymerization initiator.
Examples of the photopolymerization initiator include alkylphenone compounds, acylphosphine oxide compounds, titanocene compounds, oxime ester compounds, benzoin compounds, acetophenone compounds, benzophenone compounds, thioxanthone compounds, α-acyloxime ester compounds, phenylglyoxylate compounds, benzyl compounds, azo compounds, diphenyl sulfide compounds, iron-phthalocyanine compounds, benzoin ether compounds, and anthraquinone compounds.

From the viewpoint of reactivity, the photopolymerization initiator preferably contains at least one selected from the group consisting of alkylphenone compounds and acylphosphine oxide compounds.
From the viewpoint of transparency of the obtained cured product (that is, keeping ΔE ^* _ab low), it is preferable that the composition contains an acylphosphine oxide compound.
In order to improve the modeling accuracy of the three-dimensional object, the photopolymerization initiator is
It is preferable to include an acylphosphine oxide compound (e.g., 2,4,6-trimethylbenzoyl-diphenyl-phosphine oxide, bis(2,4,6-trimethylbenzoyl)phenylphosphine oxide, etc.),
More preferably, it comprises 2,4,6-trimethylbenzoyl-diphenyl-phosphine oxide.

The amount of photopolymerization initiator contained in the photocurable composition of the present disclosure is preferably 0.1 parts by mass to 20 parts by mass, more preferably 0.2 parts by mass to 10 parts by mass, even more preferably 0.3 parts by mass to 5 parts by mass, and even more preferably 0.3 parts by mass to 3 parts by mass, per 100 parts by mass of the photopolymerizable component.

The total content of the (meth)acrylic monomer component and the photopolymerization initiator contained in the photocurable composition of the present disclosure is preferably 50% by mass or more, more preferably 70% by mass or more, more preferably 80% by mass or more, more preferably 90% by mass or more, and more preferably 95% by mass or more, based on the total mass of the photocurable composition.

(Filler)
The photocurable composition of the present disclosure may further contain at least one filler.
As the filler, inorganic particles are preferred, and inorganic oxide particles are more preferred.
The filler is more preferably at least one selected from the group consisting of silica particles (i.e., silicon oxide particles), zirconia particles (i.e., zirconium oxide particles), aluminosilicate particles, alumina particles (i.e., aluminum oxide particles), and titania particles (i.e., titanium oxide particles).
It is particularly preferred that the filler comprises silica particles.

The average particle size of the filler is not particularly limited, but from the viewpoint of making it easier to achieve the production of test piece A1 by light irradiation, it is preferably 5 nm to 500 nm, more preferably 5 nm to 200 nm, even more preferably 5 nm to 100 nm, and even more preferably 5 nm to 70 nm.
From the viewpoint of improving abrasion resistance, the average particle size of the filler is preferably 40 nm or more, more preferably 50 nm or more, even more preferably 60 nm or more, and particularly preferably 70 nm or more.

In the present disclosure, the average particle size of the filler means the number average primary particle size, and specifically means a value measured as follows.
After obtaining a cured product (e.g., the above-mentioned test piece A1) from the photocurable composition of the present disclosure by stereolithography, a cross section of the cured product is cut out, a TEM photograph of the cross section is taken, 100 particles are randomly selected, their circle-equivalent diameters are calculated, and the obtained circle-equivalent diameters are arithmetically averaged (number-averaged).

When the photocurable composition of the present disclosure contains a filler, the content of the filler is preferably 2 parts by mass to 100 parts by mass, more preferably 5 parts by mass to 80 parts by mass, even more preferably 5 parts by mass to 60 parts by mass, and even more preferably 10 parts by mass to 50 parts by mass, relative to 100 parts by mass of the photopolymerizable component.

Depending on the purpose, the filler may be surface-treated with a surface treatment agent such as a silane coupling agent. The surface treatment agent can impart, for example, abrasion resistance to a cured product of the photocurable composition containing the filler.
The surface treatment agent is not particularly limited, but for example, a silane coupling agent can be used.
Examples of the silane coupling agent include organic silicon compounds such as methacryloxyalkyltrimethoxysilane (number of carbon atoms between the methacryloxy group and the silicon atom: 3 to 12), methacryloxyalkyltriethoxysilane (number of carbon atoms between the methacryloxy group and the silicon atom: 3 to 12), vinyltrimethoxysilane, vinylethoxysilane, and vinyltriacetoxysilane.

(Other ingredients)
The photocurable composition of the present disclosure may contain components other than the above-mentioned components, as necessary.
Examples of other components include color materials (pigments, etc.), modifiers, stabilizers, antioxidants, solvents, fluorescent brighteners, etc. Each of these other components (for example, each of the color materials, stabilizers, and fluorescent brighteners) may be contained in an amount of 0.0001% by mass to 0.1000% by mass relative to the total mass of the photocurable composition.

<Viscosity>
The photocurable composition of the present disclosure preferably has a viscosity (hereinafter also simply referred to as "viscosity") measured with an E-type viscometer at 25°C and 50 rpm of 5 mPa·s to 6000 mPa·s.
Here, rpm means revolutions per minute.
When the viscosity is from 5 mPa·s to 6000 mPa·s, the photocurable composition has excellent handleability when a three-dimensional object is produced by stereolithography.
The viscosity is more preferably 10 mPa·s to 5000 mPa·s, even more preferably 20 mPa·s to 4000 mPa·s, even more preferably 100 mPa·s to 3000 mPa·s, even more preferably 200 mPa·s to 2000 mPa·s, and even more preferably 400 mPa·s to 1500 mPa·s.

<Applications>
There are no particular limitations on the applications of the photocurable composition of the present disclosure.
The photocurable compositions of the present disclosure are preferably photocurable compositions used in the manufacture of dental products.
Examples of dental products include dentures (i.e., artificial teeth), denture bases, dental prostheses, medical instruments for use in the oral cavity, dental models, models for lost-loss casting, and the like.
Examples of dental prostheses include inlays, crowns, bridges, temporary crowns, and temporary bridges.
Examples of medical devices used in the oral cavity include mouthpieces, mouthguards, orthodontic appliances, splints (such as occlusal splints), impression trays, and surgical guides.
The dental model may include a tooth and jaw model.

[Three-dimensional objects]
The three-dimensional object of the present disclosure includes a cured product of the photocurable composition of the present disclosure described above.
The photocurable composition of the present disclosure can be suitably used as a photocurable composition for stereolithography, and more suitably used for producing splints by stereolithography.

[Dental products]
The dental product of the present disclosure includes the three-dimensional object of the present disclosure described above.
Specific examples of dental products are described above.
As the dental product, a splint including the above-mentioned three-dimensionally shaped object of the present disclosure is preferable.

Examples of the present disclosure will be described below, but the present disclosure is not limited to the following examples.
Each component will be described in detail below.

<(Meth)acrylic monomer (A)>
Specific examples of compounds classified as the (meth)acrylic monomer (A) include the following photopolymerizable components 1 to 10.
Photopolymerizable component 1: urethane diacrylate monomer (Ebecryl 8402, Daicel Allnex Corporation, molecular weight 1000)
Photopolymerizable component 2: urethane diacrylate monomer (Ebecryl 8807, Daicel Allnex Corporation, molecular weight 1000)
Photopolymerizable component 3: urethane diacrylate monomer (Ebecryl 230, Daicel Allnex Corporation, molecular weight 5000)
Photopolymerizable component 4: urethane diacrylate monomer (Ebecryl 270, Daicel Allnex Corporation, molecular weight 2000)
Photopolymerizable component 5: urethane diacrylate monomer (UA-122P, Shin-Nakamura Chemical Co., Ltd., molecular weight 1100)
Photopolymerizable component 6: urethane diacrylate monomer (UA-160TM, manufactured by Shin-Nakamura Chemical Co., Ltd., molecular weight 1600)
Photopolymerizable component 7: urethane diacrylate monomer (UN-2700, Negami Chemical Industries, Ltd., molecular weight 2000)
Photopolymerizable component 8: urethane diacrylate monomer (UN-2600, Negami Chemical Industries, Ltd., molecular weight 2500)
Photopolymerizable component 9: urethane diacrylate monomer (UN-352, Negami Chemical Industries, Ltd., molecular weight 3000)
Photopolymerizable component 10: urethane diacrylate monomer (Genomer 4230, Rahn AG, molecular weight 9950)

<(Meth)acrylic monomer (B)>
Specific examples of compounds classified as the (meth)acrylic monomer (B) include the following photopolymerizable components 11 to 20.

Photopolymerizable component 11: ethoxylated bisphenol A diacrylate (ABE-300, Shin-Nakamura Chemical Co., Ltd., molecular weight 469)
Photopolymerizable component 12: ethoxylated bisphenol A diacrylate (A-BPE-4, Shin-Nakamura Chemical Co., Ltd., molecular weight 513)
Photopolymerizable component 13: ethoxylated bisphenol A dimethacrylate (SR540, Sartomer Corporation, molecular weight 541)
Photopolymerizable component 14: urethane diacrylate (UDA, compound produced according to Production Example 1 below, molecular weight 443)
Photopolymerizable component 15: urethane dimethacrylate (UDMA, Fujifilm Wako Pure Chemical Industries, molecular weight 471)
Photopolymerizable component 16: Bifunctional urethane acrylate (AH-600, Kyoeisha Chemical Co., Ltd., molecular weight 613)
Photopolymerizable component 17: Tetraethylene glycol diacrylate (4EG-A, Kyoeisha Chemical Co., Ltd., molecular weight 302)
Photopolymerizable component 18: Nonanepropylene glycol dimethacrylate (9PG, Kyoeisha Chemical Co., Ltd., molecular weight 561)
Photopolymerizable component 19: Bifunctional urethane acrylate (PUDA-1, molecular weight 633)
Photopolymerizable component 20: Propoxylated neopentyl glycol diacrylate (SR9003NS, Arkema Co., Ltd., molecular weight 328)

<(Meth)acrylic monomer (C)>
In Tables 1 to 5, the compounds classified as the (meth)acrylic monomer (C) are specifically the following photopolymerizable components 21 to 26.

Photopolymerizable component 21: benzyl methacrylate (BZ, Kyoeisha Chemical Co., Ltd., molecular weight 176)
Photopolymerizable component 22: Phenoxyethyl methacrylate (PO, Kyoeisha Chemical Co., Ltd., molecular weight 206)
Photopolymerizable component 23: Phenoxyethyl acrylate (PO-A, Kyoeisha Chemical Co., Ltd., molecular weight 192)
Photopolymerizable component 24: m-phenoxybenzyl acrylate (POB-A, Kyoeisha Chemical Co., Ltd., molecular weight 254)
Photopolymerizable component 25: 2-(o-phenylphenoxy)ethyl acrylate (HRD-01, Nisshoku Techno Fine Chemical Co., Ltd., molecular weight 268)
Photopolymerizable component 26: 2-hydroxy-3-phenoxypropyl acrylate (M600-A, Kyoeisha Chemical Co., Ltd., molecular weight 222)

<(Meth)acrylic monomer (D)>
In Tables 1 to 5, the compounds classified as the (meth)acrylic monomer (D) are specifically the following photopolymerizable components 27 to 31.

Photopolymerizable component 27: tertiary butyl methacrylate (TB, Kyoeisha Chemical Co., Ltd., molecular weight 142)
Photopolymerizable component 28: cyclohexyl methacrylate (CH, Kyoeisha Chemical Co., Ltd., molecular weight 168)
Photopolymerizable component 29: Isobornyl methacrylate (IBX, Kyoeisha Chemical Co., Ltd., molecular weight 222)
Photopolymerizable component 30: Isobornyl acrylate (IBXA, Kyoeisha Chemical Co., Ltd., molecular weight 208)
Photopolymerizable component 31: Tetrahydrofurfuryl methacrylate (THF (1000), Kyoeisha Chemical Co., Ltd., molecular weight 170)

<Photopolymerization initiator>
Specific examples of compounds classified as photopolymerization initiators include photopolymerization initiators 1 and 2 shown below.

Photopolymerization initiator 1: acylphosphine oxide compound (Omnirad TPO: "Omnirad TPO" manufactured by IGM Resins B.V.)
Photopolymerization initiator 2: acylphosphine oxide compound (Omnirad 819: "Omnirad 819" manufactured by IGM Resins B.V.)

(Production Example 1: Production of UDA)
In a 1-liter four-neck flask equipped with a thoroughly dried stirring blade and a thermometer, 372 g (3.20 mol) of HEA, 0.71 g of DBTDL (0.1% by mass relative to the total mass of HEA and TMHDI), and 0.35 g of MEHQ (0.05% by mass relative to the total mass of HEA and TMHDI) were added, stirred until uniform, and then heated to 60 ° C. Then, 337 g (1.60 mol) of TMHDI was dropped over 1 hour. During the drop, the internal temperature rose due to the reaction heat, so the amount of drop was controlled so that it was 80 ° C. or less. After the entire amount was dropped, the reaction temperature was kept at 80 ° C. and the reaction was carried out for 10 hours. At this time, the progress of the reaction was tracked by HPLC analysis to confirm the end point of the reaction. By discharging the product from the reactor, 680 g of bifunctional urethane acrylate (UDA) was obtained. The viscosity at 25 ° C. was 7100 mPa · s.

(Production Example 2: Production of PUDA-1)
In a flask equipped with a stirring blade and a thermometer, 44.4 g (0.20 mol) of Aronix M-5700 (Toagosei), 0.063 g of DBTDL, and 0.032 g of MEHQ were added, stirred until homogeneous, and then heated to 60°C. Next, 18.8 g (0.10 mol) of XDI was added dropwise, controlling the amount so that the temperature was 80°C or less. After the entire amount was added dropwise, the reaction temperature was kept at 80°C and the reaction was carried out for 3 hours. At this time, the progress of the reaction was tracked by HPLC analysis to confirm the end point of the reaction. By discharging the product from the reactor, 63 g of urethane diacrylate (PUDA-1) was obtained. The viscosity at 65°C was 3520 mPa·s.

The abbreviations for the compounds used in the examples of the present disclosure are shown below.
HEA: Hydroxyethyl acrylate DBTDL: Dibutyltin dilaurate MEHQ: 4-Methoxyphenol TMHDI: Mixture of 2,2,4-trimethylhexamethylene diisocyanate and 2,4,4-trimethylhexamethylene diisocyanate XDI: m-Xylylene diisocyanate

<Preparation of Photocurable Composition>
Photocurable compositions were prepared using the materials shown in Tables 1 to 5.
The ΔE ^* _ab values shown in Tables 1 to 5 indicate the color difference from a transparent PMMA plate (Asahi Manufacturing, L ^* =96.98, a ^* =−0.24, b ^* =0.05).
The viscosities of all of the examples shown in Tables 1 to 5, measured using an E-type viscometer (TVE-35H, manufactured by Toki Sangyo Co., Ltd.) at 25° C. and 50 rpm, were 5 mPa·s to 6000 mPa·s.

<Methacryloyl Group Content>
The methacryloyl group content of the photocurable compositions prepared in the Comparative Examples and Examples is the ratio of the methacryloyl group content (mol/g) to the total content (mol/g) of the acryloyl group and the methacryloyl group in the composition. The results are shown in Tables 1 to 5.

<Measurement of storage modulus at 37° C.>
The storage modulus at 37° C. of the cured products obtained using the photocurable compositions prepared in the Comparative Examples and Examples was measured by the following method. The results are shown in Tables 1 to 5.
Using a 3D printer (Kulzer, Cara Print 4.0 PRO), a test piece 40 mm long, 10 mm wide, and 1 mm thick is produced using the photocurable composition to be measured, with a layer width of 50 μm, and each layer is irradiated with visible light having a wavelength of 385 nm at 11 mJ/cm ^2. The obtained test piece is irradiated with ultraviolet light having a wavelength of 365 nm at 10 J/cm ² to fully cure the photocurable composition, thereby obtaining a cured product of test piece A1.
The storage modulus of the obtained cured test piece A1 is measured at a frequency of 1 Hz while heating the test piece from 25°C to 100°C at a rate of 3°C/min using a dynamic viscoelasticity measuring device (DVA-225, manufactured by IT Measurement & Control Co., Ltd.), and the storage modulus at 37°C is read.

<Measurement of ΔE ^* _ab >
The ΔE ^* _ab of the cured products obtained using the photocurable compositions prepared in the Comparative Examples and Examples was measured by the following method. The results are shown in Tables 1 to 5.
Using a 3D printer (Kulzer, Cara Print 4.0 PRO), a test piece of 50 mm x 40 mm x 4.5 mm is produced using the photocurable composition to be measured, with a layer width of 50 μm, and each layer is irradiated with visible light of 385 nm wavelength at 11 mJ/cm ^2. The obtained test piece is irradiated with ultraviolet light of 365 nm wavelength at 10 J/cm ² to fully cure the photocurable composition, thereby obtaining a cured product of the test piece. The obtained cured test piece was polished on both sides of 50 mm x 40 mm with a rotary polisher (Ecomet 30, manufactured by Buehler) at 150 rpm, 0.15 mm on one side with 400-number abrasive paper, 0.07 mm on one side with 800-number abrasive paper, 0.02 mm on one side with 1000-number abrasive paper, and 0.01 mm on one side with 2000-number abrasive paper, for a total of 0.25 mm, and polished for 15 seconds on each side using Polishing Cloth (MasterTex Polishing Cloth 40-7742, manufactured by Buehler) and 1 g of an abrasive (high-purity alumina powder, particle size 1 μm, manufactured by Sankei Co., Ltd.) to obtain a polished test piece A2 of 50 mm x 40 mm x 4.0 mm.
Using a color difference meter (SD3000, manufactured by Nippon Denshoku Industries Co., Ltd.), measure the L ^* a ^* b ^* of a 50 mm x 40 mm surface in transmission mode using the attached STANDARD WHITE PLATE (SCI X: 94.25, Y: 99.44, Z: 106.37) as a reference. Calculate ΔE*ab using the formula ΔE*ab = (ΔL2 + Δa2 + Δb2) 1/2, using the L ^* a ^* b ^* of a 50 mm x 40 mm x 4.0 mm transparent PMMA plate ⁽ manufactured by Asahi Seisakusho Co., Ltd., L* = 96.98, a* = -0.24, b* = 0.05; color values based on "SCI X ^: _94.25 , Y _: 99.44, Z: 106.37" as a reference color).

<Evaluation of modeling properties using a 385 nm printer>
Using a 3D printer (Kulzer, Cara Print 4.0), a test piece of 50 mm x 40 mm x 4.5 mm is formed using the photocurable composition to be measured under conditions of a laminate width of 50 μm and irradiating each layer with visible light of a wavelength of 385 nm at 11 mJ/cm ² , and then irradiating the formed object with ultraviolet light of a wavelength of 365 nm at an irradiation dose of 10 J/cm ² to obtain test piece A3. The surface condition of test piece A3 is evaluated according to the following criteria. The results are shown in Tables 1 to 5.
3: The surface condition of the shaped test pieces A1 and A2 is smooth and not sticky.
2: The surface condition of the shaped test pieces A1 and A2 is not sticky, but is not smooth.
1: The surface condition of the shaped test pieces A1 and A2 is sticky and not smooth, or no test pieces can be obtained.
The inability to obtain the test piece refers to, for example, a state in which only a non-cured or gel-like specimen is obtained.

As shown in Tables 1 to 5, a photocurable composition containing a photopolymerizable component and a photopolymerization initiator was irradiated with visible light having a wavelength of 385 nm at an irradiation dose of 11 mJ/cm ² to form a cured layer A1 having a thickness of 50 μm, and the cured layer A1 was laminated in the thickness direction to form a rectangular plate-shaped object A1 having a length of 40 mm, a width of 10 mm, and a thickness of 1 mm. The object A1 was irradiated with ultraviolet light having a wavelength of 365 nm at an irradiation dose of 10 J/cm ² to produce a rectangular plate-shaped test piece A1 having a length of 40 mm, a width of 10 mm, and a thickness of 1 mm. In the examples using the photocurable composition, the storage modulus of the test piece A1 at 37 ° C. was 100 MPa or more and 1500 MPa or less, and high transparency could be ensured while maintaining mechanical strength.
In addition, since the object obtained using the photocurable composition of the examples has an excellent balance between mechanical strength and softness, it is presumed that it is less susceptible to wear due to teeth grinding, etc., and that the burden on the wearer when worn in the oral cavity is reduced.

The disclosure of Japanese Patent Application No. 2022-190496, filed on November 29, 2022, is incorporated herein by reference in its entirety.
All publications, patent applications, and standards mentioned in this specification are herein incorporated by reference to the same extent as if each individual publication, patent application, or standard was specifically and individually indicated to be incorporated by reference.

Claims (19)

A photocurable composition comprising a photopolymerizable component and a photopolymerization initiator,
The photocurable composition is irradiated with visible light having a wavelength of 385 nm at an irradiation dose of 11 mJ/ ^cm2 to form a cured layer A1 with a thickness of 50 μm, and the cured layer A1 is laminated in the thickness direction to form a rectangular plate-shaped object A1 with a length of 40 mm, a width of 10 mm and a thickness of 1 mm. The object A1 is irradiated with ultraviolet light having a wavelength of 365 nm at an irradiation dose of 10 J/ ^cm2 to produce a rectangular plate-shaped test piece A1 with a length of 40 mm, a width of 10 mm and a thickness of 1 mm. The photocurable composition has a storage modulus at 37° C. of 100 MPa or more and 1500 MPa or less. 2. The photocurable composition according to claim 1, wherein the photocurable composition is irradiated with visible light having a wavelength of 385 nm at an irradiation dose of 11 mJ/ ^cm2 to form a cured layer A2 having a thickness of 50 μm, the cured layer A2 is laminated in the thickness direction to form a rectangular plate-shaped object A2 having a length of 50 mm, a width of 40 mm, and a thickness of 4.5 mm, and the object A2 is irradiated with ultraviolet light having a wavelength of 365 nm at an irradiation dose of 10 J/ ^cm2 , and then a 50 mm x 40 mm surface is double-polished to produce a rectangular plate-shaped test piece A2 having a length of 50 mm, a width of 40 mm, and a thickness of 4.0 mm. In this case, ΔE ^* _ab of the test piece A2 is 10.0 or less. The photopolymerizable component is
A (meth)acrylic monomer (A) containing two (meth)acryloyloxy groups and having a molecular weight of 1000 or more;
a (meth)acrylic monomer (B) containing two (meth)acryloyloxy groups and having a molecular weight of 170 or more and less than 1,000;
A (meth)acrylic monomer (C) containing one (meth)acryloyloxy group and containing an aromatic ring structure;
The photocurable composition of claim 1 comprising: The photocurable composition according to claim 3, wherein the (meth)acrylic monomer (A) further contains a urethane bond. The photocurable composition according to claim 3, wherein the molecular weight of the (meth)acrylic monomer (C) is 140 to 500. The photocurable composition according to claim 3, wherein the content of the (meth)acrylic monomer (A) is 5% by mass to 60% by mass based on the total amount of the (meth)acrylic monomer components. The photocurable composition according to claim 3, wherein the content of the (meth)acrylic monomer (B) is 15% by mass to 80% by mass based on the total amount of the (meth)acrylic monomer components. The photocurable composition according to claim 3, wherein the content of the (meth)acrylic monomer (C) is 5% by mass to 70% by mass based on the total amount of the (meth)acrylic monomer components. The photocurable composition according to claim 3, wherein the photopolymerizable component includes a (meth)acrylic monomer (D) that contains one (meth)acryloyloxy group and does not have an aromatic ring structure. The photocurable composition according to claim 9, wherein the content of the (meth)acrylic monomer (D) is 1% by mass to 30% by mass based on the total amount of the (meth)acrylic monomer components. The photocurable composition according to claim 9, wherein the molecular weight of the (meth)acrylic monomer (D) is 120 to 400. The photocurable composition according to claim 3, wherein the content (mol/g) of methacryloyl groups relative to the total content (mol/g) of acryloyl groups and methacryloyl groups in the photopolymerizable component is 0% to 90%. The photocurable composition according to claim 1, wherein the photopolymerization initiator includes an acylphosphine oxide compound. The photocurable composition according to claim 1, which has a viscosity of 5 mPa·s to 6000 mPa·s measured at 25°C and 50 rpm using an E-type viscometer. The photocurable composition according to claim 1, which is a photocurable composition for photopolymerization. The photocurable composition according to claim 1, which is used to manufacture a splint by photolithography. A three-dimensional object comprising a cured product of the photocurable composition according to any one of claims 1 to 16. A dental product comprising the three-dimensional object according to claim 17. A splint including the three-dimensional object according to claim 17.