Photocurable composition and dental product

Abstract

This photocurable composition contains a (meth)acrylic monomer component and a photopolymerization initiator, and provides a cured product having an adhesive force of 1.5 N or less and a rupture elongation of 20% or more. This dental product includes a cured product of said photocurable composition.

Description

[Technical Field]

[0001] The present disclosure relates to light-curable compositions and dental products. [Background technology]

[0002] Resins have traditionally been used for a variety of purposes, and different properties are required depending on the application. For example, dental mouthpieces are used in the treatment of temporomandibular joint disorders and orthodontic treatment.

[0003] In recent years, dental products have become known, including dental prostheses, devices used in the oral cavity (such as mouthguards), and other dental products (such as gingiva masks), and various materials are used depending on their intended use. For example, Patent Document 1 discloses a mouthguard composition comprising A) a styrene block copolymer, B) at least one thermoplastic resin selected from the group consisting of alicyclic saturated hydrocarbon resins, terpene resins, and aliphatic petroleum resins, and C) at least one wax selected from the group consisting of mineral waxes, synthetic waxes, vegetable waxes, and animal waxes.

[0004] Patent Document 1: Japanese Patent Application Laid-Open No. 2003-019240 Summary of the Invention [Problem to be solved by the invention]

[0005] For example, dental products such as sports mouthpieces are often deformed during use. The deformed product may not recover its shape after use, resulting in cracks, tears, and the like. Therefore, there is a growing demand for materials that can prevent these problems. Furthermore, in dental products such as sports mouthpieces, the high adhesiveness of the product can sometimes impair handling.

[0006] Problem A that the first embodiment of the present disclosure aims to solve is to provide a photocurable composition that suppresses the occurrence of cracks and fissures and produces a cured product that is easy to handle, and a dental product that includes a cured product of this photocurable composition.

[0007] Furthermore, when using dental products such as mouthpieces, some kind of force may be applied to the contact surface between the teeth and the dental product, causing discomfort, which often manifests as pain or other discomfort. The above discomfort is often a problem when using dental products, and improvements are being sought.

[0008] Problem B to be solved by the second embodiment of the present disclosure is to provide a photocurable composition that reduces discomfort when applied to the human body and produces a cured product that is easy to handle, and a dental product having the cured product of this photocurable composition. [Means for solving the problem]

[0009] Specific means for solving at least one of the problems A and B include the following aspects. The first embodiment is as follows: <1> This is exemplified by the photocurable composition described in The second embodiment is as follows: <6> This is exemplified by the photocurable composition described in

[0010] <1> A photocurable composition comprising a (meth)acrylic monomer component and a photopolymerization initiator, the photocurable composition having an adhesive strength of 1.5 N or less and a breaking elongation of 20% or more when cured. <2> The breaking elongation of the cured product is 40% or more. <1> The photocurable composition according to claim 1. <3> A photocurable composition comprising a (meth)acrylic monomer component and a photopolymerization initiator, the photocurable composition having an adhesive strength of 1.5 N or less after curing and an impact absorption of 20% or more and 80% or less after curing. <4> The impact absorption of the cured product is 20% or more and 70% or less. <3> The photocurable composition according to claim 1. <5> The breaking elongation of the cured product is 20% or more. <3> or <4> The photocurable composition according to claim 1. <6> A photocurable composition comprising a (meth)acrylic monomer component and a photopolymerization initiator, the photocurable composition having an adhesive strength of 1.5 N or less and a Shore A hardness of 97 or less when cured. <7> The aromatic ring concentration in the (meth)acrylic monomer component is 0.00100 mol / g or more. <1> ~ <6> 1. The photocurable composition according to claim 1 . <8> The (meth)acrylic monomer component contains a (meth)acrylic monomer (A) having two (meth)acryloyl groups and a (meth)acrylic monomer (B) having one (meth)acryloyl group. <1> ~ <7> 1. The photocurable composition according to claim 1 . <9> At least one of the (meth)acrylic monomer (A) and the (meth)acrylic monomer (B) has an aromatic group. <8> The photocurable composition according to claim 1. <10> A photocurable composition comprising a (meth)acrylic monomer component and a photopolymerization initiator, wherein the (meth)acrylic monomer component comprises a (meth)acrylic monomer (A) having two (meth)acryloyl groups and a (meth)acrylic monomer (B) having one (meth)acryloyl group, wherein the molecular weight per one (meth)acryloyl group in the (meth)acrylic monomer (A) is 300 g / mol or more, and at least one of the (meth)acrylic monomer (A) and the (meth)acrylic monomer (B) has an aromatic group. <11> The content of the (meth)acrylic monomer (A) is 250 parts by mass to 800 parts by mass relative to 1000 parts by mass of the total content of the (meth)acrylic monomer (A) and the (meth)acrylic monomer (B). <8> ~ <10> 1. The photocurable composition according to claim 1 . <12> The (meth)acrylic monomer (A) contains a compound represented by the following formula (1): <8> ~ <11> 1. The photocurable composition according to claim 1 .

[0011] [ka]

[0012] (In formula (1), R 1 and R 2 each independently represents a divalent linking group, R 3 are each independently a methyl group or a hydrogen atom. <13> R 1 is a divalent chain hydrocarbon group or a group consisting of a divalent chain hydrocarbon group and at least one group selected from the group consisting of a divalent hydrocarbon group having an alicyclic structure, a divalent hydrocarbon group having an aromatic structure, and a divalent group containing a hetero atom, and the divalent hydrocarbon group having an aromatic structure is a divalent hydrocarbon group represented by the following formula (1-a): <12> The photocurable composition according to claim 1.

[0013] [ka]

[0014] (In formula (1-a), * represents a bonding position.) <14> R 1 is a divalent chain hydrocarbon group or a group consisting of a divalent chain hydrocarbon group and at least one group selected from the group consisting of a divalent hydrocarbon group having an alicyclic structure and a divalent group containing a hetero atom. <12> The photocurable composition according to claim 1. <15> R 1 wherein the divalent group containing a hetero atom contains at least one bond selected from the group consisting of a urethane bond and an ether bond. <13> or <14> The photocurable composition according to claim 1. <16> Satisfy at least one of the following (a) and (b): <8> ~ <15> 1. The photocurable composition according to claim 1 . (a) The (meth)acrylic monomer (A) comprises a (meth)acrylic monomer (A-1) having a molecular weight per (meth)acryloyl group of 300 g / mol or more and 600 g / mol or less, and a (meth)acrylic monomer (A-2) having a molecular weight per (meth)acryloyl group of more than 600 g / mol and 15,000 g / mol or less. (b) The (meth)acrylic monomer (B) contains a (meth)acrylic monomer (B-1) having two aromatic rings and a (meth)acrylic monomer (B-2) having one aromatic ring. <17> The aromatic ring concentration in the (meth)acrylic monomer (A) is 0.0016 mol / g or less. <8> ~ <16> 1. The photocurable composition according to claim 1 . <18> The total content of the (meth)acrylic monomer (A) and the (meth)acrylic monomer (B) in the (meth)acrylic monomer component is 90 mass% or more. <8> ~ <17> 1. The photocurable composition according to claim 1 . <19> Z1 obtained by the following formula β is 1 × 10 4 ~100×10 4 is <7> ~ <18> 1. The photocurable composition according to claim 1 . Z1=X1 / Y1 formula β X1 (g / mol): Molecular weight of (meth)acrylic monomer (A) per (meth)acryloyl group Y1 (mol / g): Aromatic ring concentration in the (meth)acrylic monomer component <20> Viscosity measured using an E-type viscometer at 25°C and 50 rpm is 10 mPa·s to 5000 mPa·s <1> ~ <19> 1. The photocurable composition according to claim 1 . <21> For photopolymerization <1> ~ <20> 1. The photocurable composition according to claim 1 . <22> Used to create dental products using stereolithography <1> ~ <21> 1. The photocurable composition according to claim 1 . <23> Used to create mouthpieces, gingiva masks, or lining materials by stereolithography <1> ~ <22> 1. The photocurable composition according to claim 1 . <24> <1> ~ <23> A dental product comprising a cured product of the photocurable composition according to any one of the above. <25> For mouthpieces, gingiva masks or lining materials <24> 1. A dental product according to claim 1. <26> A method for creating three-dimensional image data of a mouth guard, comprising: A method for producing three-dimensional image data of a mouth guard, comprising the step of producing three-dimensional image data of a mouth guard in which the thickness of the occlusal surface of the central incisor portion is 1.5 times or more the thickness of the occlusal surface of the second molar portion. <27> The thickness of the occlusal surface of the central incisor portion is 5 times or less than the thickness of the occlusal surface of the second molar portion. <26> A method for producing three-dimensional image data of the mouth guard described in claim 1. <28> <26> or <27> and manufacturing the mouthguard by photolithography using the three-dimensional image data of the mouthguard thus produced.

[0015] Specific means for solving the problem A include the following aspects. <1A> A photocurable composition containing a (meth)acrylic monomer component and a photopolymerization initiator, the cured product having an adhesive strength of 1.5 N or less and an elongation at break of 20% or more. <2A> The photocurable composition according to <1A>, wherein the cured product has a breaking elongation of 40% or more. <3A> A photocurable composition containing a (meth)acrylic monomer component and a photopolymerization initiator, the cured product having an adhesive strength of 1.5 N or less and an impact absorption of 20% or more and 80% or less. <4A> The photocurable composition according to <3A>, wherein the impact absorption of the cured product is 20% or more and 70% or less. <5A> The photocurable composition according to <3A> or <4A>, wherein the breaking elongation of the cured product is 20% or more. <6A> The photocurable composition according to any one of <1A> to <5A>, wherein the (meth)acrylic monomer component contains a (meth)acrylic monomer (A) having two (meth)acryloyl groups and a (meth)acrylic monomer (B) having one (meth)acryloyl group. <7A> The photocurable composition according to <6A>, wherein at least one of the (meth)acrylic monomer (A) and the (meth)acrylic monomer (B) has an aromatic group. <8A> A photocurable composition comprising a (meth)acrylic monomer component and a photopolymerization initiator, wherein the (meth)acrylic monomer component comprises a (meth)acrylic monomer (A) having two (meth)acryloyl groups and a (meth)acrylic monomer (B) having one (meth)acryloyl group, wherein the molecular weight per one (meth)acryloyl group in the (meth)acrylic monomer (A) is 300 g / mol or more, and at least one of the (meth)acrylic monomer (A) and the (meth)acrylic monomer (B) has an aromatic group. <9A> The photocurable composition according to any one of <6A> to <8A>, wherein the content of the (meth)acrylic monomer (A) is 250 parts by mass to 800 parts by mass per 1000 parts by mass of the total content of the (meth)acrylic monomer (A) and the (meth)acrylic monomer (B). <10A> The photocurable composition according to any one of <6A> to <9A>, wherein the total content of the (meth)acrylic monomer (A) and the (meth)acrylic monomer (B) in the (meth)acrylic monomer component is 90 mass% or more. <11A> The photocurable composition according to any one of <6A> to <10A>, wherein the (meth)acrylic monomer (A) contains a urethane bond. <12A> The photocurable composition according to any one of <1A> to <11A>, wherein the aromatic ring concentration in the (meth)acrylic monomer component is 0.00100 mol / g or more. <13A> The photocurable composition according to any one of <1A> to <12A>, which has a viscosity of 10 mPa·s to 5000 mPa·s at 25°C and 50 rpm as measured with an E-type viscometer. <14A> The photocurable composition according to any one of <1A> to <13A>, which is used for stereolithography. <15A> The photocurable composition according to any one of <1A> to <14A>, which is used for producing a dental product by stereolithography. <16A> The photocurable composition according to any one of <1A> to <15A>, which is used for producing a mouthpiece or a gingiva mask by stereolithography. <17A> A dental product comprising a cured product of the photocurable composition according to any one of <1A> to <16A>. <18> For mouthpieces or Gingiva masks <17> 1. A dental product according to claim 1.

[0016] Specific means for solving the problem B include the following aspects. <1B> A photocurable composition containing a (meth)acrylic monomer component and a photopolymerization initiator, the cured product having an adhesive strength of 1.5 N or less and a Shore A hardness of 97 or less. <2B> The photocurable composition according to <1B>, wherein the (meth)acrylic monomer component includes a (meth)acrylic monomer (A) having two (meth)acryloyl groups and a (meth)acrylic monomer (B) having one (meth)acryloyl group. <3B> The photocurable composition according to <2B>, wherein at least one of the (meth)acrylic monomer (A) and the (meth)acrylic monomer (B) has an aromatic group. <4B> A photocurable composition comprising a (meth)acrylic monomer component and a photopolymerization initiator, wherein the (meth)acrylic monomer component comprises a (meth)acrylic monomer (A) having two (meth)acryloyl groups and a (meth)acrylic monomer (B) having one (meth)acryloyl group, wherein the molecular weight per one (meth)acryloyl group in the (meth)acrylic monomer (A) is 300 g / mol or more, and at least one of the (meth)acrylic monomer (A) and the (meth)acrylic monomer (B) has an aromatic group, and wherein the Shore A hardness of the cured product is 97 or less. <5B> The photocurable composition according to any one of <2B> to <4B>, wherein the content of the (meth)acrylic monomer (A) is 250 parts by mass to 800 parts by mass per 1000 parts by mass of the total content of the (meth)acrylic monomer (A) and the (meth)acrylic monomer (B). <6B> The photocurable composition according to any one of <2B> to <5B>, wherein the total content of the (meth)acrylic monomer (A) and the (meth)acrylic monomer (B) in the (meth)acrylic monomer component is 90 mass% or more. <7B> The photocurable composition according to any one of <2B> to <6B>, wherein the (meth)acrylic monomer (A) contains a urethane bond. <8B> The photocurable composition according to any one of <1B> to <7B>, wherein the cured product has a Shore A hardness of 50 or more. <9B> The photocurable composition according to any one of <1B> to <8B>, wherein the aromatic ring concentration in the (meth)acrylic monomer component is 0.00100 mol / g or more. <10B> The photocurable composition according to any one of <1B> to <9B>, which has a viscosity of 10 mPa·s to 5000 mPa·s at 25°C and 50 rpm as measured with an E-type viscometer. <11B> The photocurable composition according to any one of <1B> to <10B>, which is used for stereolithography. <12B> The photocurable composition according to any one of <1B> to <11B>, which is used for producing a dental product by stereolithography. <13B> The photocurable composition according to any one of <1B> to <12B>, which is used for producing a mouthpiece or a lining material by stereolithography. <14B> A dental product comprising a cured product of the photocurable composition according to any one of <1B> to <13B>. <15B> A dental product according to <14B>, which is a mouthpiece or a lining material. [Effects of the Invention]

[0017] According to the first embodiment of the present disclosure, it is possible to provide a photocurable composition that suppresses the occurrence of cracks and fissures and produces a cured product that is easy to handle, and a dental product having a cured product of this photocurable composition.

[0018] According to the second embodiment of the present disclosure, it is possible to provide a photocurable composition that reduces discomfort when applied to the human body and produces a cured product that is easy to handle, and a dental product having a cured product of this photocurable composition. [Brief explanation of the drawings]

[0019] [Figure 1] 1 is a diagram showing the appearance of an upper jaw mouth guard according to one embodiment of the present disclosure. FIG. [Figure 2] FIG. 1 is a diagram showing the thickness of an upper jaw mouth guard on the occlusal surface (flat type) of the central incisor. [Figure 3] FIG. 1 is a diagram showing the thickness of an upper jaw mouth guard on the occlusal surface (non-flat type) of the central incisor. [Figure 4] FIG. 1 is a diagram showing the thickness of an upper jaw mouth guard on the occlusal surface (flat type) of the second molar area. [Figure 5] FIG. 1 is a diagram showing the thickness of an upper jaw mouth guard on the occlusal surface (non-flat type) of the second molar region. DETAILED DESCRIPTION OF THE INVENTION

[0020] 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 "(meth)acrylic monomer" is a concept that encompasses both acrylic monomers and methacrylic monomers. In the present disclosure, the term "(meth)acryloyloxy group" is a concept that encompasses both an acryloyloxy group and a methacryloyloxy group, and when written as "acryloyloxy group" or "methacryloyloxy group", it refers to only one of them. In this disclosure, a "urethane bond" refers to a -NHC(=O)O- bond. In the present disclosure, when referring to the amount of each component in a composition, if there are multiple substances corresponding to each component in the composition, it means the total amount of the multiple substances present in the composition, unless otherwise specified.

[0021] The photocurable composition of the present disclosure includes the following first and second embodiments.

[0022] Photocurable composition of first embodiment The photocurable composition of the first embodiment includes the following Form 1a, Form 1b, and Form 1c. Each embodiment (eg, embodiment 1a) may satisfy the features of other embodiments (eg, embodiment 1b and / or embodiment 1c).

[0023] ≪Form 1a≫ The photocurable composition according to Form 1a of the first embodiment contains a (meth)acrylic monomer component and a photopolymerization initiator, and the adhesive strength of the cured product is 1.5 N or less, and the breaking elongation of the cured product is 20% or more.

[0024] The inventors of the present disclosure focused on increasing the breaking elongation of a cured product (hereinafter simply referred to as a cured product) obtained by photocuring a photocurable composition, in order to suppress the occurrence of cracks and tears in the product. The inventors of the present disclosure have investigated the above points and have come to the knowledge that when the breaking elongation of a cured product (hereinafter simply referred to as a cured product) obtained by photocuring a photocurable composition is increased, the adhesive strength of the cured product increases, which is one of the factors that reduces handleability. That is, from the viewpoint of obtaining a cured product that is both easy to handle and suppresses cracks and tears, it is important to increase the breaking elongation of the cured product obtained by photocuring the photocurable composition and to suppress the adhesive strength of the cured product.

[0025] The photocurable composition of Form 1a contains a (meth)acrylic monomer component and a photopolymerization initiator, and the adhesive strength of the cured product is 1.5 N or less and the elongation at break of the cured product is 20% or more, so that when the photocurable composition of the first embodiment is photocured, a cured product with excellent elongation at break and reduced adhesive strength can be obtained, which makes it possible to suppress cracking and tearing and to obtain a cured product with excellent handleability.

[0026] <Adhesion strength of cured product> The adhesive strength of the cured product obtained by photocuring the photocurable composition of Form 1a is 1.5 N or less. This can improve the handleability of the cured product. From the same viewpoint as above, the adhesive strength is preferably 1.0 N or less, more preferably 0.7 N or less, and even more preferably 0.35 N or less. There is no particular lower limit to the adhesive strength of the cured product, and it may be more than 0 N or may be 0.01 N or greater.

[0027] The adhesive strength of the cured product was measured as follows. First, the photocurable composition is irradiated with visible light using a 3D printer to form a 20 mm long x 20 mm wide x 2 mm thick object (layer width: 50 μm). The visible light irradiation using the 3D printer was performed with 5.0 mJ / cm of visible light having a wavelength of 405 nm for each layer. 2 ~10mJ / cm 2 The irradiation is carried out under conditions that result in a desired thickness within the range. The object obtained above was exposed to ultraviolet light with a wavelength of 365 nm at 10 J / cm 2 The shaped object is irradiated under the conditions of (a) to completely cure the object, thereby obtaining a cured product. The obtained cured product is used to measure the adhesive strength. The cured product to be measured is placed on the sample stage, and an aluminum probe with a contact area of ​​10 mm length x 10 mm width is brought into contact with the 20 mm x 20 mm surface of the cured product, with a contact load of 0.98 ± 0.01 N / cm 2 Hold for 1.0±0.1 seconds. Then, using a tensile testing device, the probe is peeled off from the contact surface in the vertical direction at a speed of 5 mm / s. The maximum load required to peel off the probe from the contact surface is determined, and this is defined as the adhesive strength (unit: N) of the cured product in this disclosure.

[0028] <Breaking elongation of cured product> The photocurable composition of Form 1a has a breaking elongation of 20% or more for the cured product obtained by curing the photocurable composition. This makes it possible to prevent breakage (such as cracking, rupture, or fissures) from occurring when an external force is applied to the cured product. Furthermore, when the breaking elongation of the cured product is within the above range, the recovery property (improvement of recovery speed, suppression of deformation amount during recovery, etc.) of the cured product, i.e., when an external force is applied to the cured product and then the external force is removed, the shape of the cured product returns to the shape before the external force was applied, can be improved. Furthermore, when the breaking elongation of the cured product is within the above range and the adhesive strength of the cured product is 1.5 N or less, the recovery property can be further improved. Furthermore, when the breaking elongation of the cured product is within the above range and the adhesive strength of the cured product is 1.5 N or less, the amount of deformation during recovery can be more effectively suppressed.

[0029] From the above viewpoint, the breaking elongation of the cured product is preferably 40% or more, and more preferably 60% or more.

[0030] The upper limit of the elongation at break may be 110% or less, 100% or less, or 90% or less.

[0031] In the present disclosure, the breaking elongation of the cured product is measured by the following method. First, the photocurable composition is irradiated with visible light using a 3D printer to form the photocurable composition into the shape of a dumbbell-shaped test piece conforming to ISO 37-2, thereby obtaining a shaped object (layer width 50 μm). The visible light irradiation using the above 3D printer was performed with 5.0 mJ / cm of visible light with a wavelength of 405 nm for each layer. 2 ~10mJ / cm 2 The irradiation is carried out under conditions that result in a desired thickness within the range. The object obtained above was exposed to ultraviolet light with a wavelength of 365 nm at 10 J / cm 2 The shaped object is irradiated under the conditions of (a) to completely cure the object, thereby obtaining a cured product. The cured product thus obtained is used to measure the breaking elongation. The breaking elongation of the cured product to be measured is measured in accordance with ISO 37:2017 using a tensile testing device at a tensile speed of 500±50 mm / min.

[0032] (Hardness of cured product (Shore A hardness)) The hardness of the cured product of Form 1a is preferably 50 or more. Generally, the lower the hardness (i.e., the softer) of a cured product, the more likely it is that its adhesive strength will increase. However, by ensuring that the hardness of the cured product is 50 or higher, the adhesive strength of the cured product can be better suppressed. The upper limit of the hardness of the cured product is not particularly limited, but may be 99 or less. Furthermore, as mentioned above, generally, the lower the hardness (i.e., the softer) the cured product, the more likely it is that its adhesive strength will increase. However, when the photocurable composition of the first embodiment is used, the adhesive strength of the resulting cured product can be suppressed even if the hardness is 90 or less, and can also be suppressed even if the hardness is 80 or less. In the present disclosure, the hardness of the cured product is measured by the following method. First, the photocurable composition is irradiated with visible light using a 3D printer to form a 25 mm long x 25 mm wide x 6 mm thick object (layer width: 50 μm). The visible light irradiation using the 3D printer was performed with 5.0 mJ / cm of visible light having a wavelength of 405 nm for each layer. 2 ~10mJ / cm 2 The irradiation is carried out under conditions that result in a desired thickness within the range. The object obtained above was exposed to ultraviolet light with a wavelength of 365 nm at 10 J / cm 2 The shaped object is irradiated under the conditions of (a) to completely cure the object, thereby obtaining a cured product. The obtained cured product is used to measure the hardness. The hardness of the cured product is measured in accordance with ISO 7619-1:2010.

[0033] (viscosity) From the viewpoint of suitability for producing dental products by stereolithography, the viscosity of the photocurable composition of Form 1a, measured using an E-type viscometer at 25°C and 50 revolutions per minute (rpm), is preferably 10 mPa·s to 5000 mPa·s, and more preferably 20 mPa·s to 3000 mPa·s. The lower limit of the viscosity is more preferably 50 mPa·s. The upper limit of the viscosity is more preferably 2000 mPa·s, even more preferably 1500 mPa·s, and particularly preferably 1200 mPa·s.

[0034] ≪Form 1b≫ The photocurable composition according to embodiment 1b contains a (meth)acrylic monomer component and a photopolymerization initiator, and the adhesive strength of the cured product is 1.5 N or less, and the impact absorption of the cured product is 20% or more and 80% or less.

[0035] From the viewpoint of suppressing the occurrence of cracks and fissures in products, the inventors of the present disclosure focused on the impact absorption properties of a cured product (hereinafter simply referred to as a cured product) obtained by photocuring a photocurable composition. The inventors of the present disclosure have investigated the above points and have come to the knowledge that when the impact absorption properties of a cured product are increased, the adhesive strength of the cured product increases, which is one of the factors that reduces handleability.

[0036] The photocurable composition of Form 1b contains a (meth)acrylic monomer component and a photopolymerization initiator, and the adhesive strength of the cured product is 1.5 N or less, and the impact absorption of the cured product is 20% or more and 80% or less. Therefore, when the photocurable composition of the first embodiment is photocured, a cured product that is less susceptible to cracks and tears and has excellent handleability can be obtained.

[0037] In the embodiment 1b, the adhesive strength of the cured product is the same as in the above-mentioned embodiment 1a, and the same applies to the preferred embodiment.

[0038] <Shock absorption> The impact absorption of the cured product of form 1b is 20% or more and 80% or less. When the impact absorption of the cured product is 20% or more, the occurrence of breakage (such as cracking, rupture, or fissures) in the cured product can be suppressed. From the same viewpoint as above, the impact absorption of the cured product is preferably 30% or more, and more preferably 40% or more.

[0039] By keeping the impact absorption of the cured product at 80% or less, the adhesive strength of the cured product can be prevented from becoming excessively large, thereby maintaining ease of handling. From the same viewpoint as above, the impact absorption of the cured product is preferably 70% or less, and more preferably 60% or less.

[0040] When the impact absorption of the cured product is within the above range and the adhesive strength of the cured product is 1.5 N or less, the recovery property can be improved as in the case of the breaking elongation described above, and the amount of deformation during recovery can also be better suppressed.

[0041] Examples of methods for adjusting the impact absorption value include a method for adjusting the impact absorption value by adjusting the aromatic ring concentration of the (meth)acrylic monomer component, and a method for adjusting the impact absorption value by adjusting the (meth)acryloyl group concentration (mol / g) of the (meth)acrylic monomer (A) described below. Details will be described later.

[0042] ~Method for measuring shock absorption~ The method for measuring the impact absorption of the cured product in the present disclosure is as follows. First, the photocurable composition is irradiated with visible light using a 3D printer to form a 20 mm long x 20 mm wide x 3 mm thick object (layer width: 50 μm). The visible light irradiation using the 3D printer was performed with 5.0 mJ / cm of visible light having a wavelength of 405 nm for each layer. 2 ~10mJ / cm 2 The irradiation is carried out under conditions that result in a desired thickness within the range. The object obtained above was exposed to ultraviolet light with a wavelength of 365 nm at 10 J / cm 2 The shaped object is irradiated under the conditions of (1) to fully cure, thereby obtaining a cured product. The obtained cured product is kept at 37°C for 15 minutes, and the impact absorption properties are measured. In the present disclosure, the impact absorption property of a cured product refers to the degree of reduction in the maximum load measured by a load cell when an iron ball is freely dropped onto the cured product. More specifically, the value A calculated by the following formula is defined as the impact absorption (A, unit: %) of the cured product in the present disclosure.

[0043]

number

[0044] In the above formula, A (%) represents impact absorption, N0 represents the maximum load measured by the load cell when, at 23°C, a zirconia plate 1 mm thick, 30 mm long and 30 mm wide is placed on the load cell, and an iron ball (16.7 mm diameter, 18.8 g) is allowed to fall freely onto the center of the zirconia plate from a position 50 cm above the load cell. N represents the maximum load measured by the load cell at 23°C when a zirconia plate 1 mm thick, 30 mm long x 30 mm wide is placed on a load cell, and a cured product to be measured, 3 mm thick, 20 mm long x 20 mm wide, is placed in the center of the zirconia plate, and an iron ball (16.7 mm diameter, 18.8 g) is allowed to freely fall from a position 50 cm above the load cell onto the center of the cured product.

[0045] ≪Form 1c≫ The photocurable composition according to Form 1c of the first embodiment comprises a (meth)acrylic monomer component and a photopolymerization initiator, wherein the (meth)acrylic monomer component comprises a (meth)acrylic monomer (A) having two (meth)acryloyl groups and a (meth)acrylic monomer (B) having one (meth)acryloyl group, wherein the molecular weight per one (meth)acryloyl group in the (meth)acrylic monomer (A) is 300 g / mol or more, and at least one of the (meth)acrylic monomer (A) and the (meth)acrylic monomer (B) has an aromatic group. Hereinafter, each component contained in the photocurable composition in Form 1a, Form 1b, and Form 1c of the first embodiment will be described in detail.

[0046] <(Meth)acrylic monomer component> The photocurable composition of the first embodiment contains a (meth)acrylic monomer component. This can improve the breaking elongation of the resulting cured product. The (meth)acrylic monomer component can be any component containing a (meth)acrylic monomer without any particular limitation. Among the above, from the viewpoint of obtaining a cured product having excellent elongation at break and suppressed adhesive strength, it is preferable that the (meth)acrylic monomer component contains a (meth)acrylic monomer (A) having two (meth)acryloyl groups and a (meth)acrylic monomer (B) having one (meth)acryloyl group.

[0047] In the photocurable composition of the first embodiment, the (meth)acrylic monomer component preferably has an aromatic group. The (meth)acrylic monomer component in the first embodiment contains an acryloyl group. Generally, since the acryloyl group has properties such as hydrophilicity, when a cured product is produced using a photocurable composition containing a (meth)acrylic monomer, the adhesive strength of the cured product tends to increase. However, when the (meth)acrylic monomer component has an aromatic group, the adhesive strength of the resulting cured product can be effectively suppressed due to the hydrophobicity of the aromatic group itself and the π-π interaction between the aromatic groups. As a result, the photocurable composition of the first embodiment can better suppress the adhesive strength of the cured product even when a (meth)acrylic monomer containing an acryloyl group is used, which may increase the adhesive strength of the cured product.

[0048] Generally, when the cured product has high hygroscopicity, the cured product is more likely to break at the site where it has absorbed moisture. In the above respects, since aromatic groups are highly hydrophobic, by using a (meth)acrylic monomer having an aromatic group in the photocurable composition of the first embodiment, the hygroscopicity of the obtained cured product can be reduced and the breaking elongation of the cured product can be improved favorably.

[0049] Furthermore, by increasing the concentration of aromatic rings, the impact absorption can be increased, and by keeping the concentration of aromatic rings low, the impact absorption can be decreased.

[0050] From the above viewpoints, the aromatic ring concentration in the (meth)acrylic monomer component is preferably 0.00100 mol / g or more, more preferably 0.00250 mol / g or more, and even more preferably 0.00450 mol / g or more. The upper limit of the aromatic ring concentration in the (meth)acrylic monomer component is preferably 0.010 mol / g or less, and more preferably 0.008 mol / g or less, from the viewpoint of suppressing yellowing of the cured product.

[0051] Examples of the aromatic group include a phenyl group, a phenylene group, a naphthyl group, and an anthracene group. Among the above, the aromatic group is preferably a phenyl group or a phenylene group.

[0052] ((Meth)acrylic monomer (A) having two (meth)acryloyl groups) The (meth)acrylic monomer component in the first embodiment preferably contains a (meth)acrylic monomer (A) having two (meth)acryloyl groups. The (meth)acrylic monomer (A) has no (meth)acryloyl groups other than the two (meth)acryloyl groups. The (meth)acrylic monomer (A) may be one type or two or more types, as long as it is a (meth)acrylic monomer having two (meth)acryloyl groups. The (meth)acrylic monomer (A) is preferably a (meth)acrylic monomer having two (meth)acryloyloxy groups.

[0053] The (meth)acrylic monomer (A) preferably contains a urethane bond, which can improve the elongation at break of the resulting cured product. The number of urethane bonds contained in the (meth)acrylic monomer (A) is preferably 1 to 5, more preferably 2 to 4, and even more preferably 2, from the viewpoints of the breaking elongation and adhesive strength of the resulting cured product.

[0054] By increasing the (meth)acryloyl group equivalent of the (meth)acrylic monomer (A) (i.e., by increasing the molecular weight of the (meth)acrylic monomer (A)), the impact absorption can be increased, and by decreasing the (meth)acryloyl group equivalent, the impact absorption can be decreased. In other words, the impact absorption can be increased by decreasing the (meth)acryloyl group concentration (mol / g) of the (meth)acrylic monomer (A), and the impact absorption can be decreased by increasing the (meth)acryloyl group concentration (mol / g) of the (meth)acrylic monomer (A).

[0055] From the above viewpoint and from the viewpoint of improving the hardness of the resulting cured product, the (meth)acryloyl group concentration (mol / g) in the (meth)acrylic monomer (A) is preferably 0.001 mol / g to 0.01 mol / g, and more preferably 0.001 mol / g to 0.005 mol / g.

[0056] The (meth)acrylic monomer (A) preferably contains a compound represented by the following formula (1). The (meth)acrylic monomer (A) is also preferably a compound represented by the following formula (1).

[0057] [ka] In formula (1), R 1 and R 2 each independently represents a divalent linking group, R 3 are each independently a methyl group or a hydrogen atom.

[0058] In the above formula (1), R 1 is preferably a divalent organic group, and more preferably a divalent organic group which may have one or more selected from the group consisting of an aromatic structure, an alicyclic structure, an ether bond, an ester bond, and a urethane bond.

[0059] R in Equation (1) 1 In the formula (I), the divalent organic group preferably contains a divalent chain hydrocarbon group, It is more preferable that the alkyl group contains at least one group selected from the group consisting of a divalent chain hydrocarbon group, a divalent hydrocarbon group having a cyclic structure, and a divalent group containing a hetero atom. The cyclic structure includes an aromatic structure and an alicyclic structure.

[0060] The divalent chain hydrocarbon group may be saturated or unsaturated and may have a substituent. The divalent chain hydrocarbon group may be a straight-chain or branched-chain alkylene group.

[0061] R in Equation (1) 1 Preferably, the copolymer contains an oxyalkylene structure or a polyester structure from the viewpoints of suppressing the viscosity of the photocurable composition, improving the elongation at break of the resulting cured product, and suppressing the adhesive strength of the resulting cured product. From the same viewpoint as above, R in formula (1) 1 is preferably a divalent chain hydrocarbon group having no substituent.

[0062] R in Equation (1) 1 In the formula (I), the number of carbon atoms in the divalent organic group may be, for example, in the range of 5 to 2,500, and preferably in the range of 5 to 2,000.

[0063] R in Equation (1) 1 In the formula (I), the divalent organic group may contain a heteroatom, such as an oxygen atom or a nitrogen atom.

[0064] R in Equation (1) 1 In the above, examples of the divalent hydrocarbon group having an aromatic structure include an arylene group, an alkylenearylene group, an alkylenearylenealkylene group, and an arylenealkylenearylene group.

[0065] R in Equation (1) 1 In the above, examples of the divalent hydrocarbon group having an alicyclic structure include a cyclopropylene group, a cyclobutylene group, a cyclopentylene group, a cyclohexylene group, a cyclohexenylene group, a cycloheptylene group, a cyclooctylene group, a cyclononylene group, a cyclodecylene group, a cycloundecylene group, a cyclododecylene group, a cyclotridecylene group, a cyclotetradecylene group, a cyclopentadecylene group, a cyclooctadecylene group, a cycloicosylene group, a bicyclohexylene group, a norbornylene group, an isobornylene group, and an adamantylene group.

[0066] R in Equation (1) 1 may have a substituent, and examples of the substituent include a linear or branched alkyl group having 1 to 6 carbon atoms.

[0067] In formula (1), from the viewpoint of restoring property and shock absorption, R 1is preferably a divalent chain hydrocarbon group or a group consisting of a divalent chain hydrocarbon group and at least one group selected from the group consisting of a divalent hydrocarbon group having an alicyclic structure, a divalent hydrocarbon group having an aromatic structure, and a divalent group containing a hetero atom, R 1 is more preferably a divalent chain hydrocarbon group or a group consisting of a divalent chain hydrocarbon group and at least one group selected from the group consisting of a divalent hydrocarbon group having an alicyclic structure and a divalent group containing a hetero atom.

[0068] From the viewpoint of recovery and impact absorption, the divalent hydrocarbon group having an aromatic structure is preferably a divalent hydrocarbon group represented by the following formula (1-a). Also, from the viewpoint of suppressing yellowing of the cured product and improving weather resistance, the divalent hydrocarbon group having an aromatic structure is preferably a divalent hydrocarbon group represented by the following formula (1-a):

[0069] [ka]

[0070] (In formula (1-a), * represents a bonding position.)

[0071] From the viewpoint of resilience and shock absorption, R 1 It is preferable that the divalent group containing a hetero atom in the formula (I) contains at least one bond selected from the group consisting of a urethane bond and an ether bond.

[0072] In the above formula (1), R 2 are preferably each independently a divalent chain hydrocarbon group which may have a substituent. R 2 A divalent chain hydrocarbon group suitable as R 1 The divalent chain hydrocarbon groups are the same as those suitable for R 2 The divalent chain hydrocarbon group represented by R preferably has 2 to 6 carbon atoms, and more preferably has 2 to 3 carbon atoms. 2From the viewpoint of suppressing viscosity, the divalent chain hydrocarbon group as is preferably an unsubstituted divalent chain hydrocarbon group having 2 to 6 carbon atoms, more preferably 2 to 3 carbon atoms.

[0073] R 2 When has a substituent, examples of the substituent include an alkyl group having 1 to 6 carbon atoms, such as a methyl group or an ethyl group; an aryl group; a cycloalkyl group having 3 to 6 carbon atoms, such as a cyclopentyl group or a cyclohexyl group; a tolyl group, a xylyl group, a cumyl group; a styryl group; or an alkoxyphenyl group, such as a methoxyphenyl group, an ethoxyphenyl group, or a propoxyphenyl group.

[0074] The molecular weight of the (meth)acrylic monomer (A) is preferably 600 to 30,000, more preferably 800 to 20,000, and even more preferably 1,000 to 5,000 in terms of weight average molecular weight.

[0075] From the viewpoint of recovery and impact absorption, the aromatic ring concentration in the (meth)acrylic monomer (A) is preferably 0.0020 mol / g or less, and more preferably 0.0016 mol / g or less. The aromatic ring concentration in the (meth)acrylic monomer (A) may be, for example, 0.0010 mol / g or more.

[0076] (Molecular weight per (meth)acryloyl group) The molecular weight per one (meth)acryloyl group in the (meth)acrylic monomer (A) is preferably 300 g / mol or more. This can further improve the breaking elongation of the cured product. From the same viewpoint as above, it is more preferable that the molecular weight per one (meth)acryloyl group in the (meth)acrylic monomer (A) is 600 g / mol or more. The molecular weight per (meth)acryloyl group in the (meth)acrylic monomer (A) is preferably 15,000 g / mol or less, more preferably 10,000 g / mol or less, and even more preferably 2,000 g / mol or less.

[0077] The molecular weight per one (meth)acryloyl group in the (meth)acrylic monomer (A) is preferably 50 g / mol to 15,000 g / mol, more preferably 150 g / mol to 10,000 g / mol, and even more preferably 250 g / mol to 2,000 g / mol. When a plurality of (meth)acrylic monomers are contained as the (meth)acrylic monomer (A), the molecular weight per (meth)acryloyl group is calculated as the mass average value of the molecular weights of the respective (meth)acrylic monomers.

[0078] ((Meth)acrylic monomer (B) having one (meth)acryloyl group) The (meth)acrylic monomer component in the first embodiment preferably contains a (meth)acrylic monomer (B) having one (meth)acryloyl group, and the (meth)acrylic monomer (B) does not have any other (meth)acryloyl groups other than the one (meth)acryloyl group. The (meth)acrylic monomer (B) may be one type or two or more types, as long as it is an acrylic monomer having one (meth)acryloyl group.

[0079] The (meth)acrylic monomer (B) preferably contains a ring structure, which can improve the hardness of the resulting cured product and suppress the adhesive strength of the resulting cured product. The ring structure is preferably an aromatic structure or an alicyclic structure, more preferably an aromatic structure.

[0080] When the (meth)acrylic monomer (B) contains an aromatic structure, the number of aromatic rings contained in the (meth)acrylic monomer (B) is preferably 1 to 4, and more preferably 2 or 3.

[0081] The (meth)acrylic monomer (B) is preferably a compound represented by the following formula (2) or (3), and more preferably a compound represented by the following formula (2).

[0082] [ka]

[0083] In formula (2), R 6 is a monovalent organic group which may have a ring structure. In formula (3), R 7 and R 8 are each independently a monovalent organic group which may have a ring structure or a hydrogen atom, and R 7 and R 8 may be bonded to each other to form a ring.

[0084] The (meth)acrylic monomer (B) is preferably a compound represented by formula (2), and R 6 is preferably a monovalent organic group having a ring structure (preferably an aromatic ring structure) and having 3 to 30 carbon atoms, and more preferably a monovalent organic group having a ring structure (preferably an aromatic ring structure) and having 6 to 20 carbon atoms.

[0085] In formula (2), R 6 may have a structure represented by the following formula (4): *-L1-A (4) In formula (4), L1 is a single bond or a divalent chain hydrocarbon group of 1 to 30 carbon atoms which may have a heteroatom of O or N, and A is a hydrogen atom, a monovalent alicyclic group of 3 to 30 carbon atoms which may have a heteroatom of O or N, or an aryl group of 6 to 30 carbon atoms. * represents a bonding position.

[0086] In formula (4), the divalent chain hydrocarbon group having 1 to 30 carbon atoms, represented by L1, which may have a heteroatom of O or N, may be linear or branched. L1 preferably has 1 to 20 carbon atoms, more preferably 1 to 10 carbon atoms, and further preferably 1 to 8 carbon atoms. When L1 contains a heteroatom, the number of heteroatoms is preferably 1 to 6, and more preferably 1 or 2.

[0087] L1 may have a substituent. Suitable examples of the substituent for L1 include an alkyl group having 1 to 3 carbon atoms, a hydroxy group, and an alkyl group having 1 to 3 carbon atoms in which one or two hydrogen atoms are substituted with a hydroxy group. L1 may contain a urethane bond. When L1 contains a urethane bond, the number of urethane bonds may be 1 or 2.

[0088] In formula (4), examples of the monovalent alicyclic group represented by A and having 3 to 20 carbon atoms, which may have a heteroatom of O or N, include a cyclopropyl group, a cyclobutyl group, a cyclopentyl group, a cyclohexyl group, a cyclohexenyl group, a cycloheptyl group, a cyclooctyl group, a cyclononyl group, a cyclodecyl group, a cycloundecyl group, a cyclododecyl group, a cyclotridecyl group, a cyclotetradecyl group, a cyclopentadecyl group, a cyclooctadecyl group, a cycloicosyl group, a bicyclohexyl group, a norbornyl group, an isobornyl group, an adamantyl group, a morpholyl group, a piperidino group, a piperazino group, and a dioxane group. The number of carbon atoms in the monovalent alicyclic group is preferably 5 to 12, and more preferably 6 to 10.

[0089] In formula (4), examples of the aromatic structure represented by A include a phenyl structure, a biphenyl structure, a naphthyl structure, and an anthryl structure.

[0090] A may have a substituent. Suitable examples of the substituent for A include an alkyl group having 1 to 6 carbon atoms such as a methyl group or an ethyl group; a hydroxy group; an alkyl group having 1 to 6 carbon atoms in which one or two hydrogen atoms are substituted with a hydroxy group; an aryl group; a cycloalkyl group having 3 to 6 carbon atoms such as a cyclopentyl group or a cyclohexyl group; a tolyl group, a xylyl group, a cumyl group; a styryl group; and an alkoxyphenyl group such as a methoxyphenyl group, an ethoxyphenyl group, or a propoxyphenyl group.

[0091] In formula (2), the total number of carbon atoms in -L1-A is preferably 1 to 30, and more preferably 1 to 20.

[0092] In equation (3), R 7 and R 8 are each independently a monovalent organic group which may have a ring structure or a hydrogen atom, and R 7 and R 8 may be bonded to each other to form a ring. Suitable R 7 and R 8 Examples of the hydrocarbon group include monovalent hydrocarbon groups having 1 to 30 carbon atoms which may have a heteroatom of O or N. The hydrocarbon group may be linear or branched, saturated or unsaturated, and may have a substituent. R 7 and R 8 The alkyl group preferably has 1 to 20 carbon atoms, and more preferably has 1 to 10 carbon atoms.

[0093] R 7 and R 8 Examples of the organic group in R include alkyl groups having 1 to 30 carbon atoms, such as methyl, ethyl, and propyl, which may have a heteroatom of O or N. 7 and R 8 It is preferred that one of the groups is a hydroxyethyl group or a butoxymethyl group, and the other is a hydrogen atom. R 7 and R 8When one of the above is a hydroxyethyl group or a butoxymethyl group and the other is a hydrogen atom, examples of the (meth)acrylic monomer (B) include the following.

[0094] R 7 and R 8 Examples of the (meth)acrylic monomer (B) in which the groups bond to each other to form a ring include the following.

[0095] [ka]

[0096] The molecular weight of the (meth)acrylic monomer (B) is not particularly limited, but the weight average molecular weight is preferably 80-500, more preferably 100-400, and even more preferably 130-320.

[0097] Examples of compounds suitable as the (meth)acrylic monomer (B) include the compounds used in the examples described below.

[0098] In the photocurable composition of the first embodiment, at least one of the (meth)acrylic monomer (A) and the (meth)acrylic monomer (B) preferably has a ring structure. This can further improve the breaking elongation of the resulting cured product, and can suppress the adhesive strength of the resulting cured product. Examples of the ring structure include an aromatic group and an alicyclic group.

[0099] In the photocurable composition of the first embodiment, at least one of the (meth)acrylic monomer (A) and the (meth)acrylic monomer (B) preferably has an aromatic group. As described above, when at least one of the (meth)acrylic monomer (A) and the (meth)acrylic monomer (B) has an aromatic group, the adhesive strength of the resulting cured product can be effectively suppressed. Furthermore, by using a (meth)acrylic monomer having an aromatic group in the photocurable composition of the first embodiment, the moisture absorption of the resulting cured product can be reduced, and the breaking elongation of the cured product can be improved.

[0100] In the photocurable composition of the first embodiment, the content of the (meth)acrylic monomer (A) is preferably 250 parts by mass to 800 parts by mass, more preferably 350 parts by mass to 650 parts by mass, and even more preferably 380 parts by mass to 500 parts by mass, relative to 1000 parts by mass of the total content of the (meth)acrylic monomer (A) and the (meth)acrylic monomer (B).

[0101] In the photocurable composition of the first embodiment, the total content of the (meth)acrylic monomer (A) and the (meth)acrylic monomer (B) in the (meth)acrylic monomer component is preferably 90% by mass or more, and more preferably 95% by mass or more.

[0102] The photocurable composition of the first embodiment may contain acrylic rubber particles. When the photocurable composition of the first embodiment contains acrylic rubber particles, the content of the acrylic rubber particles in the photocurable composition of the first embodiment is preferably 0.1% by mass to 30% by mass. When the photocurable composition of the first embodiment contains acrylic rubber particles, the total content of the (meth)acrylic monomer (A), the (meth)acrylic monomer (B), and the acrylic rubber particles in the (meth)acrylic monomer component is preferably 90% by mass or more, and more preferably 95% by mass or more.

[0103] The (meth)acrylic monomer (A) and (meth)acryloyl (B) in the first embodiment can improve the tensile elongation of the cured product and reduce adhesive strength. Therefore, Z in the following formula α, which is calculated using the molecular weight (g / mol) of the (meth)acrylic monomer (A) per one (meth)acryloyl group [i.e., molecular weight of the (meth)acrylic monomer (A) / number of (meth)acryloyl groups in the (meth)acrylic monomer (A)] and the aromatic ring concentration (mol / g) in the (meth)acrylic monomer component, is preferably greater than 0, more preferably 0.00100 to 100, and even more preferably 0.200 to 50. Z=X×Y formula α X (g / mol): (molecular weight of (meth)acrylic monomer (A) per (meth)acryloyl group) - 200 Y (mol / g): Aromatic ring concentration in (meth)acrylic monomer component (mol / g) - 0.00100

[0104] The (meth)acrylic monomer (A) and (meth)acryloyl (B) in the first embodiment can improve the tensile elongation of the cured product, reduce the adhesive strength, and further improve the recovery property. Therefore, Z1 in the following formula β calculated using the molecular weight (g / mol) of the (meth)acrylic monomer (A) per one (meth)acryloyl group and the aromatic ring concentration (mol / g) in the (meth)acrylic monomer component is 5×10 3 ~500×10 4 Preferably, it is 1×10 4 ~100×10 4 It is more preferable that: The upper limits of these ranges are also preferable from the viewpoint of improving formability (for example, surface roughness, etc.). The lower limits of these ranges are also preferable from the viewpoint of suppressing yellowing. Z1=X1 / Y1 formula β X1 (g / mol): Molecular weight of (meth)acrylic monomer (A) per (meth)acryloyl group Y1 (mol / g): Aromatic ring concentration in the (meth)acrylic monomer component

[0105] The photocurable composition of the first embodiment preferably satisfies at least one of the following (a) and (b): (a) The (meth)acrylic monomer (A) comprises a (meth)acrylic monomer (A-1) having a molecular weight per (meth)acryloyl group of 300 g / mol or more and 600 g / mol or less, and a (meth)acrylic monomer (A-2) having a molecular weight per (meth)acryloyl group of more than 600 g / mol and 15,000 g / mol or less. (b) The (meth)acrylic monomer (B) contains a (meth)acrylic monomer (B-1) having two aromatic rings and a (meth)acrylic monomer (B-2) having one aromatic ring.

[0106] By satisfying at least one of (a) and (b), the photocurable composition of the first embodiment exhibits a good balance of adhesive strength, elongation at break, and impact resistance, and further improves recovery.

[0107] Examples of the (meth)acrylic monomer (A-1) having a molecular weight per (meth)acryloyl group of 300 g / mol or more and 600 g / mol or less include AH-600 (manufactured by Kyoeisha Chemical Co., Ltd.) and MMD-352, which will be described later. Examples of the (meth)acrylic monomer (A-2) having a molecular weight per (meth)acryloyl group of more than 600 g / mol and not more than 15,000 g / mol include UA-160™ (manufactured by Shin-Nakamura Chemical Co., Ltd.), UA-122P (manufactured by Shin-Nakamura Chemical Co., Ltd.), UN-2700 (manufactured by Negami Chemical Industrial Co., Ltd.), UN-2600 (manufactured by Negami Chemical Industrial Co., Ltd.), UN-352 (manufactured by Negami Chemical Industrial Co., Ltd.), Ebecryl 8402 (manufactured by Daicel-Allnex Corporation), and Ebecryl 230 (manufactured by Daicel-Allnex Corporation), which will be described later.

[0108] The content of the (meth)acrylic monomer (A-1) is preferably 50 parts by mass to 450 parts by mass, more preferably 80 parts by mass to 350 parts by mass, and even more preferably 100 parts by mass to 250 parts by mass, relative to 1000 parts by mass of the total content of the (meth)acrylic monomer (A) and the (meth)acrylic monomer (B).

[0109] The content of the (meth)acrylic monomer (A-2) is preferably 200 to 850 parts by mass, more preferably 220 to 650 parts by mass, and even more preferably 250 to 500 parts by mass, relative to 1000 parts by mass of the total content of the (meth)acrylic monomer (A) and the (meth)acrylic monomer (B).

[0110] In addition, whether the photocurable composition of the first embodiment contains only one of the (meth)acrylic monomer (A-1) and the (meth)acrylic monomer (A-2) or both, the contents of the (meth)acrylic monomer (A-1) and the (meth)acrylic monomer (A-2) are preferably within the above-mentioned ranges.

[0111] The proportion of the content of the (meth)acrylic monomer (A-1) relative to the total content of the (meth)acrylic monomer (A-1) and the (meth)acrylic monomer (A-2) is preferably 10% by mass to 70% by mass, more preferably 15% by mass to 50% by mass, and even more preferably 20% by mass to 40% by mass.

[0112] Examples of the (meth)acrylic monomer (B-1) having two aromatic rings include POBA (manufactured by Kyoeisha Chemical Co., Ltd.), HRD01 (manufactured by Nisshoku Techno Fine Chemical Co., Ltd.), and M110 (manufactured by Toagosei Co., Ltd.).

[0113] Examples of the (meth)acrylic monomer (B-2) having one aromatic ring include PO-A (manufactured by Kyoeisha Chemical Co., Ltd.), M113 (manufactured by Toa Gosei Co., Ltd.), P2H-A (manufactured by Kyoeisha Chemical Co., Ltd.), BZ (manufactured by Kyoeisha Chemical Co., Ltd.), M-600A (manufactured by Kyoeisha Chemical Co., Ltd.), PO (manufactured by Kyoeisha Chemical Co., Ltd.), and M111 (manufactured by Toa Gosei Co., Ltd.).

[0114] The content of the (meth)acrylic monomer (B-1) is preferably 100 parts by mass to 600 parts by mass, more preferably 150 parts by mass to 500 parts by mass, and even more preferably 200 parts by mass to 450 parts by mass, relative to 1000 parts by mass of the total content of the (meth)acrylic monomer (A) and the (meth)acrylic monomer (B).

[0115] The content of the (meth)acrylic monomer (B-2) is preferably 100 parts by mass to 600 parts by mass, more preferably 150 parts by mass to 500 parts by mass, and even more preferably 200 parts by mass to 450 parts by mass, relative to 1000 parts by mass of the total content of the (meth)acrylic monomer (A) and the (meth)acrylic monomer (B). In addition, whether the photocurable composition of the first embodiment contains only one of the (meth)acrylic monomer (B-1) and the (meth)acrylic monomer (B-2) or both, the contents of the (meth)acrylic monomer (B-1) and the (meth)acrylic monomer (B-2) are preferably within the above-mentioned ranges.

[0116] The content of the (meth)acrylic monomer (B-1) relative to the total content of the (meth)acrylic monomer (B-1) and the (meth)acrylic monomer (B-2) is preferably 20% by mass to 80% by mass, more preferably 30% by mass to 70% by mass, and even more preferably 40% by mass to 60% by mass.

[0117] (Other additives in the (meth)acrylic monomer component) The (meth)acrylic monomer component in the first embodiment may contain additives other than the (meth)acrylic monomer (A) and the (meth)acrylic monomer (B). Examples of other additives include trifunctional (meth)acrylic monomers. Among the above, trifunctional (meth)acrylic monomers can reduce the adhesive strength of the cured product, but they may also reduce the breaking elongation of the cured product, so it is preferable to add only a small amount within a range that allows the breaking elongation to be maintained.

[0118] (Photopolymerization initiator) The photocurable composition of the first embodiment contains a photopolymerization initiator. The photopolymerization initiator is not particularly limited as long as it generates radicals when irradiated with light, but it is preferable that it generates radicals at the wavelength of light used in stereolithography. The wavelength of light used in stereolithography is generally 365 nm to 500 nm, but in practice it is preferably 365 nm to 430 nm, and more preferably 365 nm to 420 nm.

[0119] Examples of photopolymerization initiators that generate radicals at the wavelength of light used in stereolithography include alkylphenone compounds, acylphosphine oxide compounds, titanocene compounds, oxime ester compounds, benzoin compounds, acetophenone compounds, benzophenone compounds, thioxanthone compounds, α-acyloxime ester compounds, phenyl glyoxylate compounds, benzyl compounds, azo compounds, diphenyl sulfide compounds, organic dye compounds, iron phthalocyanine compounds, benzoin ether compounds, and anthraquinone compounds. Among these, alkylphenone compounds and acylphosphine oxide compounds are preferred from the viewpoint of reactivity and the like.

[0120] An example of the alkylphenone compound is 1-hydroxy-cyclohexyl-phenyl-ketone (Omnirad184: manufactured by IGM Resins). Examples of acylphosphine oxide compounds include bis(2,4,6-trimethylbenzoyl)-phenylphosphine oxide (Omnirad819: manufactured by IGM Resins) and 2,4,6-trimethylbenzoyl-diphenyl-phosphine oxide (OmniradTPO: manufactured by IGM Resins).

[0121] The photocurable composition of the first embodiment may contain only one type of photopolymerization initiator, or may contain two or more types. The content of the photopolymerization initiators in the photocurable composition of the first embodiment (total content when two or more types are used) is preferably 0.1% by mass to 10% by mass, more preferably 0.2% by mass to 5% by mass, and even more preferably 0.3% by mass to 3% by mass.

[0122] <Other ingredients> The photocurable composition of the first embodiment may contain one or more components other than the (meth)acrylic monomer (A), the (meth)acrylic monomer (B) and the photopolymerization initiator, as needed. When the photocurable composition contains the other components, the total mass of the (meth)acrylic monomer (A), the (meth)acrylic monomer (B), and the photopolymerization initiator is preferably 30% by mass or more, more preferably 50% by mass or more, even more preferably 70% by mass or more, still more preferably 80% by mass or more, still more preferably 90% by mass or more, and particularly preferably 95% by mass or more, based on the total amount of the photocurable composition.

[0123] Examples of other components include monomers other than the (meth)acrylic monomer (A) and the (meth)acrylic monomer (B). When the photocurable composition contains, as other components, monomers other than the (meth)acrylic monomer (A) and the (meth)acrylic monomer (B), the content of the monomers as other components is preferably 50% by mass or less, more preferably 30% by mass or less, even more preferably 20% by mass or less, and particularly preferably 10% by mass or less, based on the total amount of the (meth)acrylic monomer (A) and the (meth)acrylic monomer (B).

[0124] Examples of other components include coloring materials, coupling agents such as silane coupling agents (e.g., 3-acryloxypropyltrimethoxysilane), rubber agents, ion trapping agents, ion exchange agents, leveling agents, plasticizers, additives such as antifoaming agents, and thermal polymerization initiators. When the photocurable composition of the first embodiment contains a thermal polymerization initiator, photocuring and thermal curing can be performed in combination. Examples of the thermal polymerization initiator include a thermal radical generator and an amine compound.

[0125] The method for preparing the photocurable composition of the first embodiment is not particularly limited, and examples thereof include a method of mixing the (meth)acrylic monomer (A) and the (meth)acrylic monomer (B), and a photopolymerization initiator (and other components as necessary). The means for mixing the components is not particularly limited, and examples include ultrasonic dissolution, a twin-arm mixer, a roll mixer, a twin-screw extruder, a ball mill mixer, and a planetary mixer. The photocurable composition of this embodiment may be prepared by mixing the components, filtering the mixture to remove impurities, and then subjecting the mixture to a vacuum degassing treatment.

[0126] ≪Cured product≫ The method for photocuring the photocurable composition of the first embodiment is not particularly limited, and any known method and apparatus can be used. For example, a method can be used in which a step of forming a thin film made of the photocurable composition of the first embodiment and a step of irradiating the thin film with light to obtain a cured layer are repeated multiple times to laminate multiple cured layers, thereby producing a cured product of a desired shape. The resulting cured product may be used as is, or may be used after further post-curing, such as by light irradiation or heating, to improve its mechanical properties and shape stability.

[0127] <Stereolithography> The photocurable composition of the first embodiment is preferably for use in stereolithography. In particular, the photocurable composition of the first embodiment can be suitably used in a modeling method using a 3D printer. In this disclosure, "stereolithography" is a type of three-dimensional modeling method using a 3D printer.

[0128] <3D printer> Examples of photolithography methods include the SLA (Stereo Lithography Apparatus) method, the DLP (Digital Light Processing) method, and the inkjet method. The photocurable composition of this embodiment is particularly suitable for SLA or DLP stereolithography.

[0129] The SLA method includes a method in which a photocurable composition is irradiated with spot-shaped ultraviolet laser light to obtain a three-dimensional object. When producing dental products and the like by the SLA method, for example, the photocurable composition of this embodiment is stored in a container, and the liquid surface of the photocurable composition is selectively irradiated with spot-like ultraviolet laser light so as to obtain a desired pattern, thereby curing the photocurable composition and forming a cured layer of the desired thickness on a modeling table. Next, the modeling table is lowered, and one layer of liquid photocurable composition is supplied on top of the cured layer, cured in the same manner, and this lamination operation is repeated to obtain successive cured layers. In this way, dental products and the like can be produced.

[0130] The DLP method includes a method in which a three-dimensional object is obtained by irradiating a photocurable composition with planar light. For methods of obtaining a three-dimensional object by the DLP method, reference can be made to the descriptions in, for example, Japanese Patent Nos. 5111880 and 5235056, as appropriate. When producing dental products, etc. using the DLP method, for example, a lamp that emits light other than laser light, such as a high-pressure mercury lamp, an ultra-high-pressure mercury lamp, or a low-pressure mercury lamp, or an LED, is used as the light source, a planar drawing mask having a plurality of digital micromirror shutters arranged in a plane is placed between the light source and the modeling surface of the photocurable composition, and light is irradiated onto the modeling surface of the photocurable composition through the planar drawing mask to sequentially laminate cured layers having a predetermined geometric pattern. In this way, dental products, etc. can be produced.

[0131] The inkjet method includes a method in which droplets of a photocurable composition are continuously ejected from an inkjet nozzle onto a substrate, and the droplets adhering to the substrate are irradiated with light to obtain a three-dimensional object. When producing dental products and the like by the inkjet method, for example, a head equipped with an inkjet nozzle and a light source is scanned in a plane while a photocurable composition is ejected from the inkjet nozzle onto a substrate, and the ejected photocurable composition is irradiated with light to form a cured layer, and these operations are repeated to sequentially stack cured layers, thereby producing dental products and the like.

[0132] <Dental products> The photocurable composition of the first embodiment is suitable for use in producing dental products by stereolithography. Furthermore, the photocurable composition of the first embodiment is suitably used for producing a mouthpiece, gingiva mask or backing material by stereolithography, and is more suitably used for producing a mouthpiece or gingiva mask.

[0133] The dental product of the first embodiment preferably comprises a cured product of the photocurable composition of the first embodiment. Dental products containing a cured product (i.e., a photofabricated product) of the photocurable composition of the first embodiment are not particularly limited and can be used for artificial teeth, prostheses, medical instruments used in the oral cavity, models (such as gingiva masks), etc., but instruments or models used in the oral cavity are preferred, and those for mouthpieces (particularly, sports mouthpieces), gingiva masks, or lining materials are more preferred, and those for mouthpieces (particularly, sports mouthpieces) or gingiva masks are even more preferred. It is preferable to use a cured product of the photocurable composition of the first embodiment in at least a part of a dental product. Examples of instruments used in the oral cavity include sports mouthpieces, mouthguards, orthodontic mouthpieces, splints such as occlusion adjustment splints or splints for treating temporomandibular joint disorders, and mouthpieces used to treat sleep apnea syndrome. By using a cured product of the photocurable composition of the first embodiment, it is possible to produce a medical device that has an excellent feel when used in the oral cavity and that has sufficient strength and hardness.

[0134] <Mouthguard manufacturing method and mouthguard> When the dental product of the first embodiment is a mouthguard, the mouthguard is preferably manufactured by stereolithography. The method for manufacturing a mouth guard in the first embodiment includes a step of creating three-dimensional image data of a mouth guard in which the thickness of the occlusal surface of the central incisor portion is at least 1.5 times the thickness of the occlusal surface of the second molar portion, and it is preferable to manufacture the mouth guard by photolithography. The mouth guard in the first embodiment is a photofabricated product, and the thickness of the occlusal surface of the central incisor portion is preferably 1.5 times or more the thickness of the occlusal surface of the second molar portion.

[0135] Traditionally, mouthguards have been made using commercially available mouthguard sheets and a suction molding machine. In this case, the thickness of the occlusal surface of the mouthguard tends to be uniform, and adjusting the occlusal surface takes a lot of time. While it is possible to adjust the thickness by placing multiple sheets on specific areas, it is difficult to set the conditions for mouthguard production, and it requires the skill and time of the worker.

[0136] In the first embodiment, when a mouth guard is produced using a 3D printer with a photocurable composition, the thickness of the occlusal surface of the central incisor portion in the 3D image data of the mouth guard is set to preferably 1.5 to 5 times, and more preferably 2 to 4 times, the thickness of the occlusal surface of the second molar portion, and CAD design is performed. The mouth guard is then produced using stereolithography with a 3D printer, which eliminates or simplifies adjustment of the occlusal surface, thereby significantly reducing the time required to produce the mouth guard.

[0137] The central incisor portion of the mouthguard is the portion on the mouthguard that corresponds to the central incisor of the teeth, and is the portion on the mouthguard that comes into contact with the central incisor when the mouthguard is worn. The second molar portion of the mouthguard is the portion on the mouthguard that corresponds to the second molar of the teeth and that comes into contact with the second molar when the mouthguard is worn. Furthermore, there are two central incisor regions and two second molar regions on the right and left sides of the upper and lower jaws (that is, a total of four on each side of the upper and lower jaws). Among the central incisor portions and second molar portions, the thickness of the occlusal surface of at least one central incisor portion and second molar portion may be 1.5 times or more the thickness of the occlusal surface of the second molar portion, or the thickness of the occlusal surface of all central incisor portions and second molar portions may be 1.5 times or more the thickness of the occlusal surface of the second molar portion, or the average value of the thicknesses of the occlusal surfaces of all central incisor portions may be 1.5 times or more the average value of the thicknesses of the occlusal surfaces of all second molar portions. If the thickness of the occlusal surface of the central incisor is 1.5 times or more the thickness of the occlusal surface of the second molar, it will be easier to bring the central incisor into contact with the mouth guard when biting, so significant occlusal adjustments will not be necessary. Furthermore, if the thickness of the occlusal surface of the central incisor is less than five times the thickness of the occlusal surface of the second molar, it will be easier to bring the second molar into contact with the mouth guard, and significant occlusal adjustments will not be necessary.

[0138] The thickness of the occlusal surface of the second molar portion is preferably 0.2 mm to 5 mm, and more preferably 0.5 mm to 4 mm. If the thickness of the occlusal surface of the second molar is 0.2 mm or more, the strength of the mouth guard can be maintained satisfactorily. Furthermore, if the thickness of the occlusal surface of the second molar portion is 5 mm or less, the degree of mouth opening can be reduced, and discomfort felt by the wearer can be reduced.

[0139] The occlusal surface thickness refers to the thickness of the mouthguard at the occlusal surface of a specific tooth when worn. Specifically, it refers to the shortest distance between the surface that comes into contact with the tip of a tooth and the surface opposite the surface that comes into contact with the tip of the tooth in the tooth portion of the mouthguard that comes into contact with the teeth when worn. In other words, the thickness of the occlusal surface means the thickness of the thinnest part of the mouth guard that is bitten down between the teeth when the mouth guard is worn. The opposing surface is the surface of the mouth guard that faces the surface that comes into contact with the tips of the teeth.

[0140] FIG. 1 is a diagram showing the appearance of an upper jaw mouth guard according to one embodiment of the present disclosure. As shown in FIG. 1, the maxillary mouth guard 10 in one embodiment of the present disclosure includes a second molar portion 1 that guards the maxillary second molar, and a central incisor portion 2 that guards the maxillary central incisor. FIG. 2 is a diagram showing the thickness of the maxillary mouth guard on the occlusal surface (flat type) of the central incisor. FIG. 3 is a diagram showing the thickness of an upper jaw mouth guard on the occlusal surface (non-flat type) of the central incisor portion. When the occlusal surface is flat, it is called an occlusal surface (flat type). When the occlusal surface is not flat, it is called an occlusal surface (non-flat type).

[0141] For example, as shown in Figures 2 and 3, the thickness 5 of the occlusal surface of the central incisor portion refers to the shortest distance between the surface 3 that contacts the tip of the central incisor and the opposing surface 4 that faces the surface 3 that contacts the tip of the central incisor in the central incisor portion of the maxillary mouth guard 10, which is the portion that contacts the central incisor when the maxillary mouth guard 10 is worn.

[0142] FIG. 4 is a diagram showing the thickness of the maxillary mouth guard on the occlusal surface (flat type) of the second molar area. FIG. 5 is a diagram showing the thickness of an upper jaw mouth guard on the occlusal surface (non-flat type) of the second molar area. For example, as shown in Figures 4 and 5, the thickness 8 of the occlusal surface of the second molar portion refers to the shortest distance between the surface 6 that contacts the tip of the second molar and the opposing surface 7 that faces the surface 6 that contacts the tip of the second molar in the second molar portion of the maxillary mouth guard 10, which is the portion that contacts the second molar when the maxillary mouth guard 10 is worn.

[0143] Furthermore, the thickness of the mouth guard produced with a 3D printer using the method of the first embodiment can be freely changed using CAD design, and the wearing comfort can be improved by designing it so that only the sides of the molar area are made thinner.

[0144] The photocurable composition used in the method for producing the present mouth guard is not limited to the photocurable composition of the first embodiment, and any composition that can be photoformed can be used.

[0145] The mouthguard manufactured by this method is an appliance used in the oral cavity and configured to cover the teeth and gums. The mouthguard to be manufactured is not particularly limited, but is preferably an upper jaw mouthguard.

[0146] Photocurable composition of second embodiment The photocurable composition of the second embodiment includes the following form 2a and form 2b.

[0147] ≪Form 2a≫ The photocurable composition according to Form 2a of the second embodiment contains a (meth)acrylic monomer component and a photopolymerization initiator, and the adhesive strength of the cured product is 1.5 N or less, and the Shore A hardness of the cured product is 97 or less.

[0148] The inventors of the present disclosure believed that the hardness of the cured product (hereinafter simply referred to as the cured product) obtained by photocuring a photocurable composition causes discomfort when applied to the human body. For example, when the cured material is used as a mouthpiece, a strong occlusal force is applied to the contact surface between the mouthpiece and the upper and lower teeth through the mouthpiece due to the occlusion of the teeth. In this case, if the hardness of the cured material is high, the occlusal force is more easily transmitted to the teeth, which is thought to cause discomfort such as pain. On the other hand, the inventors of the present disclosure have found that when the hardness of the cured product is reduced, the adhesive strength of the cured product increases, which causes a decrease in handleability. That is, from the viewpoint of obtaining a cured product that reduces discomfort when applied to the human body and is easy to handle, it is important to specify the hardness of the cured product obtained by photocuring the photocurable composition within a range that can reduce discomfort and to reduce the adhesive strength of the cured product.

[0149] The photocurable composition of Form 2a contains a (meth)acrylic monomer component and a photopolymerization initiator, and the adhesive strength of the cured product is 1.5 N or less, and the Shore A hardness of the cured product is 97 or less. Therefore, when the photocurable composition of the second embodiment is photocured, a cured product can be obtained that is less uncomfortable when applied to the human body and is easy to handle.

[0150] The preferred range, definition, measurement method, and other details of the adhesive strength of the cured product of the second embodiment are the same as those described in <Adhesive strength of cured product> of the first embodiment above.

[0151] (Hardness of cured product (Shore A hardness)) The photocurable composition of Form 2a has a Shore A hardness of 97 or less after curing. By making the Shore A hardness of the cured product 97 or less, discomfort when the cured product is applied to the human body is reduced. Furthermore, while the lower the hardness of a cured product, the greater the tendency for its adhesive strength to increase, when the photocurable composition of the second embodiment is used, the adhesive strength of the resulting cured product can be suppressed even if the hardness of the cured product is 97 or less. From the same viewpoint as above, the Shore A hardness of the cured product is preferably 95 or less, and more preferably 93 or less. Furthermore, the photocurable composition of Form 2a preferably has a hardness of 50 or more after being cured. Generally, the lower the hardness (i.e., the softer) of a cured product, the more likely it is that its adhesive strength will increase. However, by ensuring that the hardness of the cured product is 50 or higher, the adhesive strength of the cured product can be better suppressed. From the same viewpoint as above, the hardness of the cured product of the photocurable composition of Form 2a is more preferably 66 or more, and even more preferably 80 or more. In the present disclosure, the hardness of the cured product is measured by the following method. First, the photocurable composition is irradiated with visible light using a 3D printer to form a 25 mm long x 25 mm wide x 6 mm thick object (layer width: 50 μm). The visible light irradiation using the 3D printer was performed with 5.0 mJ / cm of visible light having a wavelength of 405 nm for each layer. 2 ~10mJ / cm 2 The irradiation is carried out under conditions that result in a desired thickness within the range. The object obtained above was exposed to ultraviolet light with a wavelength of 365 nm at 10 J / cm 2 The shaped object is irradiated under the conditions of (a) to completely cure the object, thereby obtaining a cured product. The obtained cured product is used to measure the hardness. The hardness of the cured product is measured in accordance with ISO 7619-1:2010.

[0152] <Breaking elongation of cured product> The photocurable composition of the second embodiment preferably has a breaking elongation of 10% or more of the cured product obtained by curing the photocurable composition. This makes it possible to prevent breakage (such as cracking, rupture, or fissures) from occurring when an external force is applied to the cured product. Furthermore, when the breaking elongation of the cured product is within the above range, the recovery property (improvement of recovery speed, suppression of deformation amount during recovery, etc.) of the cured product, i.e., when an external force is applied to the cured product and then the external force is removed, the shape of the cured product returns to the shape before the external force was applied, can be improved. Furthermore, when the breaking elongation of the cured product is within the above range and the adhesive strength of the cured product is 1.5 N or less, the recovery property can be further improved. Furthermore, when the breaking elongation of the cured product is within the above range and the adhesive strength of the cured product is 1.5 N or less, the amount of deformation during recovery can be more effectively suppressed.

[0153] From the above viewpoints, the breaking elongation of the cured product is preferably 20% or more, more preferably 40% or more, and even more preferably 60% or more.

[0154] In the present disclosure, the breaking elongation of the cured product is measured by the following method. First, the photocurable composition is irradiated with visible light using a 3D printer to form the photocurable composition into the shape of a dumbbell-shaped test piece conforming to ISO 37-2, thereby obtaining a shaped object (layer width 50 μm). The visible light irradiation using the above 3D printer was performed with 5.0 mJ / cm of visible light with a wavelength of 405 nm for each layer. 2 ~10mJ / cm 2 The irradiation is carried out under conditions that result in a desired thickness within the range. The object obtained above was exposed to ultraviolet light with a wavelength of 365 nm at 10 J / cm 2 The shaped object is irradiated under the conditions of (a) to completely cure the object, thereby obtaining a cured product. The cured product thus obtained is used to measure the breaking elongation. The breaking elongation of the cured product to be measured is measured in accordance with ISO 37:2017 using a tensile testing device at a tensile speed of 500±50 mm / min.

[0155] The preferred range of viscosity, details of the measurement method, etc. in the second embodiment are the same as the preferred range, details of the measurement method, etc. described in (Viscosity) in the first embodiment above.

[0156] ≪Form 2b≫ The photocurable composition according to Form 2b of the second embodiment comprises a (meth)acrylic monomer component and a photopolymerization initiator, wherein the (meth)acrylic monomer component comprises a (meth)acrylic monomer (A) having two (meth)acryloyl groups and a (meth)acrylic monomer (B) having one (meth)acryloyl group, wherein the molecular weight per one (meth)acryloyl group in the (meth)acrylic monomer (A) is 300 g / mol or more, at least one of the (meth)acrylic monomer (A) and the (meth)acrylic monomer (B) has an aromatic group, and the Shore A hardness of the cured product is 97 or less. The components contained in the photocurable compositions of Form 2a and Form 2b of the second embodiment will be described in detail below.

[0157] Specific examples, preferred aspects, and other details of the (meth)acrylic monomer component of the second embodiment are the same as those described in the <(meth)acrylic monomer component> of the first embodiment above.

[0158] Specific examples, preferred aspects, etc. of the (meth)acrylic monomer (A) having two (meth)acryloyl groups of the second embodiment are the same as the specific examples, preferred aspects, etc. described above in the first embodiment ((meth)acrylic monomer (A) having two (meth)acryloyl groups).

[0159] The preferred range of the molecular weight per one (meth)acryloyl group, details of the calculation method, etc. in the second embodiment are the same as the preferred range, details of the calculation method, etc. described in (Molecular weight per one (meth)acryloyl group) in the first embodiment described above.

[0160] Details of specific examples, preferred aspects, etc. of the (meth)acrylic monomer (B) having one (meth)acryloyl group in the second embodiment are the same as the details of specific examples, preferred aspects, etc. described in the ((meth)acrylic monomer (B) having one (meth)acryloyl group) in the first embodiment described above.

[0161] In the photocurable composition of the second embodiment, at least one of the (meth)acrylic monomer (A) and the (meth)acrylic monomer (B) preferably has a ring structure. Details of specific examples, preferred aspects, etc. of the ring structure in the second embodiment are the same as details of specific examples, preferred aspects, etc. of the ring structure that at least one of the (meth)acrylic monomer (A) and the (meth)acrylic monomer (B) in the first embodiment may have.

[0162] In the photocurable composition of the second embodiment, at least one of the (meth)acrylic monomer (A) and the (meth)acrylic monomer (B) preferably has an aromatic group. Details of specific examples, preferred aspects, etc. of the aromatic group in the second embodiment are the same as details of specific examples, preferred aspects, etc. of the aromatic group that at least one of the (meth)acrylic monomer (A) and the (meth)acrylic monomer (B) in the first embodiment may have.

[0163] In the photocurable composition of the second embodiment, the content of the (meth)acrylic monomer (A) is preferably 250 parts by mass to 800 parts by mass, and more preferably 350 parts by mass to 650 parts by mass, relative to 1000 parts by mass of the total content of the (meth)acrylic monomer (A) and the (meth)acrylic monomer (B).

[0164] In the photocurable composition of the second embodiment, the total content of the (meth)acrylic monomer (A) and the (meth)acrylic monomer (B) in the (meth)acrylic monomer component is preferably 90% by mass or more, and more preferably 95% by mass or more.

[0165] The photocurable composition of the second embodiment may contain acrylic rubber particles. Specific examples, preferred aspects, and other details of the acrylic rubber particles in the second embodiment are the same as the specific examples, preferred aspects, and other details of the acrylic rubber particles that can be contained in the photocurable composition in the first embodiment.

[0166] In the second embodiment, it is preferable that Z in the formula α described in the first embodiment is within the range shown in the section on formula α described in the first embodiment.

[0167] In the second embodiment, it is preferable that Z1 in the formula β described in the first embodiment is within the range shown in the section on the formula β described in the first embodiment.

[0168] The photocurable composition of the second embodiment preferably satisfies at least one of (a) and (b) described in the above-mentioned section on the first embodiment. Furthermore, the details of (a) and (b) such as specific examples, preferred aspects, definitions, contents, etc. of the (meth)acrylic monomer (A-1), the (meth)acrylic monomer (A-2), the (meth)acrylic monomer (B-1), and the (meth)acrylic monomer (B-2) are the same as the details of (a) and (b) such as specific examples, preferred aspects, definitions, contents, etc. of the (meth)acrylic monomer (A-1), the (meth)acrylic monomer (A-2), the (meth)acrylic monomer (B-1), and the (meth)acrylic monomer (B-2) in the first embodiment described above.

[0169] (Other additives in the (meth)acrylic monomer component) The (meth)acrylic monomer component in the second embodiment may contain additives other than the (meth)acrylic monomer (A) and the (meth)acrylic monomer (B). Details of specific examples, preferred aspects, etc. of other additives in the second embodiment are the same as the details of specific examples, preferred aspects, etc. of other additives described in the section (Other additives in the (meth)acrylic monomer component) in the first embodiment above.

[0170] (Photopolymerization initiator) The photocurable composition of the second embodiment contains a photopolymerization initiator. Details of specific examples, preferred aspects, etc. of the photopolymerization initiator in the second embodiment are the same as the details of specific examples, preferred aspects, etc. of the photopolymerization initiator in the first embodiment described above.

[0171] <Other ingredients> The photocurable composition of the second embodiment may contain one or more components other than the (meth)acrylic monomer (A), the (meth)acrylic monomer (B) and the photopolymerization initiator, as needed. Specific examples, preferred aspects, and other details of other components in the second embodiment are the same as the details of specific examples, preferred aspects, and other details of other components in the first embodiment described above.

[0172] The method for preparing the photocurable composition of the second embodiment is not particularly limited, and examples thereof include a method of mixing the (meth)acrylic monomer (A) and the (meth)acrylic monomer (B), and a photopolymerization initiator (and other components as necessary). Details are as described above in the first embodiment.

[0173] ≪Cured product≫ Specific examples, preferred aspects, and other details of the cured product of the second embodiment are the same as those described above in the section "Cured Product" of the first embodiment.

[0174] <Stereolithography> The photocurable composition of the second embodiment is preferably for use in stereolithography. Regarding the photocurable composition of the second embodiment for use in photolithography, the preferred aspects, details of definitions, etc. are the same as the preferred aspects, details of definitions, etc. described in the above-mentioned <Photolithography> of the first embodiment.

[0175] <3D printer> Details of specific examples, preferred aspects, etc. of the 3D printer in the second embodiment are the same as the details of specific examples, preferred aspects, etc. described in the <3D printer> of the first embodiment above.

[0176] <Dental products> The photocurable composition of the second embodiment is suitable for use in producing dental products by stereolithography. Furthermore, the photocurable composition of the second embodiment is suitably used for producing a mouthpiece, gingiva mask or backing material by stereolithography, and is more suitably used for producing a mouthpiece or gingiva mask.

[0177] <Mouthguard manufacturing method and mouthguard> When the dental product of the second embodiment is a mouthguard, the mouthguard is preferably manufactured by stereolithography. The specific details of the manufacturing method, preferred aspects, etc. are the same as those of the manufacturing method, preferred aspects, etc. described in <Manufacturing method of mouth guard and mouth guard> of the first embodiment above. [Example]

[0178] Hereinafter, one embodiment of the present disclosure will be specifically described using examples, but the present disclosure is not limited to these examples.

[0179] Example A Example A is an example for more specifically explaining the first embodiment of the present disclosure. <Preparation of Photocurable Composition> [Examples 1A to 43A, Comparative Examples 2A to 3A] Photocurable compositions were obtained by mixing the components shown in the following Tables 1 to 3. Table 1 shows the viscosity of each photocurable composition. The viscosity was measured in the same manner as described above.

[0180] Comparative Example 1A Gingiva Mask (manufactured by NextDent) was used as the photocurable composition.

[0181] <Evaluation> The obtained test pieces were subjected to the following measurements and evaluations. The results are shown in Tables 1 to 3.

[0182] (breaking elongation) The obtained photocurable composition was printed using a 3D printer (Kulzer, Cara Print 4.0) with visible light at a wavelength of 405 nm and an illuminance of 8.0 mJ / cm. 2 Under the conditions above, a dumbbell-shaped test piece conforming to ISO 37-2 was shaped to obtain a shaped object (layer width 50 μm). The obtained shaped object was irradiated with ultraviolet light of 365 nm wavelength at 10 J / cm. 2 The photopolymerization product was cured by irradiation under the conditions of (a) to (c). The breaking elongation of the obtained stereolithography object (hereinafter referred to as "test piece") was measured in accordance with ISO 37: 2017. These measurements were performed using a tensile testing device (manufactured by Shimadzu Corporation) at a tensile speed of 500±50 mm / min.

[0183] (Shore A hardness) The obtained photocurable composition was printed using a 3D printer (Kulzer, Cara Print 4.0) with visible light at a wavelength of 405 nm and an illuminance of 8.0 mJ / cm. 2 Under these conditions, a 25mm long x 25mm wide x 6mm thick object (layer width 50μm) was obtained. The obtained object was exposed to ultraviolet light with a wavelength of 365nm at 10J / cm. 2 The object was irradiated under the conditions of (a) to completely cure the object, thereby obtaining a photo-fabricated object (i.e., a cured object). The Shore A hardness of the obtained stereolithography object (hereinafter referred to as "test piece") was measured in accordance with ISO 7619-1: 2010. The hardness was measured using a durometer-type hardness tester (manufactured by Mitutoyo Corporation), and the value measured 15 seconds after penetration was taken as the Shore A hardness value.

[0184] (Adhesive strength) The obtained photocurable composition was printed using a 3D printer (Kulzer, Cara Print 4.0) with visible light at a wavelength of 405 nm and an illuminance of 8.0 mJ / cm. 2 Under these conditions, a 20mm long x 20mm wide x 2mm thick object (layer width 50μm) was obtained. The obtained object was exposed to ultraviolet light with a wavelength of 365nm at 10J / cm. 2 The object was irradiated under the conditions of (a) to (c) and completely cured, thereby obtaining a photo-fabricated object. The resulting stereolithography (hereinafter referred to as "test piece") was attached to a sample stage so as not to sag. Next, an aluminum probe with a contact area of ​​10 mm length × 10 mm width was brought into contact with the 20 mm length × 20 mm width surface of the test piece, and a pressure of 0.98 ± 0.01 N / cm 2 The contact load was maintained for 1.0±0.1 seconds. Thereafter, the probe was peeled off from the contact surface in the vertical direction at a speed of 5±0.5 mm per second using a tensile testing device (Shimadzu Corporation). The maximum load required to peel off the probe from the contact surface was determined and used as the adhesive strength (unit: N) of the cured product.

[0185] (shock absorption) The obtained photocurable composition was printed using a 3D printer (Kulzer, Cara Print 4.0) with visible light at a wavelength of 405 nm and an illuminance of 8.0 mJ / cm. 2 Under the above conditions, a 20mm long x 20mm wide x 3mm thick object (layer width 50μm) was obtained. 10J / cm for the resulting object 2 The object was irradiated with ultraviolet light having a wavelength of 365 nm under the above conditions to effect final curing, thereby obtaining a photo-fabricated object. The impact absorption (A (%)) of the obtained stereolithography object (hereinafter referred to as "test piece") was measured by the method described above. The maximum load was measured using a small tension / compression dual-purpose load cell (LMU-200N, manufactured by Imada Co., Ltd.) connected to a load output device (ZT Digital Force Gauge, manufactured by Imada Co., Ltd.). The maximum load was measured at a temperature of 23°C on the test piece within 30 seconds after being held at 37°C for 15 minutes. The free fall of the iron ball was carried out in an air atmosphere.

[0186] (shape recovery test) The obtained photocurable composition was printed using a 3D printer (Kulzer, Cara Print 4.0) with visible light at a wavelength of 405 nm and an illuminance of 8.0 mJ / cm. 2 Under the above conditions, a molded object (layer width 50 μm) measuring 8 mm in length, 39 mm in width, and 4 mm in thickness was obtained. 10J / cm for the resulting object 2 The object was irradiated with ultraviolet light having a wavelength of 365 nm under the above conditions to effect final curing, thereby obtaining a photo-fabricated object. The obtained stereolithography object (hereinafter referred to as "test piece") was bent by applying stress so that both ends of the test piece in the longitudinal (horizontal) direction were in contact with each other, and the test piece was held for 10 seconds. After that, the stress was released and the change in shape of the test piece was observed and evaluated according to the following criteria. S: After stress release, the original shape was restored in 0 seconds or more and less than 1 second. A: After the stress was released, the original shape was restored in 1 second or more but less than 3 seconds. B: After the stress was released, the original shape was recovered in 3 seconds or more but less than 10 seconds. C: The original shape was not restored 10 seconds after the stress was released, but no cracks or fractures occurred. D: A crack occurred in the test specimen while stress was applied for 10 seconds, and the test specimen was broken by the time the stress was released.

[0187] [Table 1]

[0188] [Table 2]

[0189] [Table 3]

[0190] In Tables 1 to 3, the numbers in the "Composition" column for each example and comparative example are shown in parts by mass. In Tables 1 to 3, the notation "AE+B (A and B are arbitrary numbers)" means A x 10 B means. In Tables 1 to 3, the details of each component are as follows:

[0191] <(Meth)acrylic Monomer (A) Having Two (Meth)acryloyloxy Groups and Two Urethane Bonds> The structures of the (meth)acrylic monomers (A) having two (meth)acryloyloxy groups and two urethane bonds shown in Tables 1 to 3 are as follows:

[0192] [ka]

[0193] [ka]

[0194] UA-160TM Shin-Nakamura Chemical Co., Ltd., urethane diacrylate monomer with polyether skeleton UA-122P Shin-Nakamura Chemical Co., Ltd., urethane diacrylate monomer with polyether skeleton UN-6305 Negami Chemical Industrial Co., Ltd., urethane diacrylate monomer with polyether structure UN-2700 Negami Chemical Industrial Co., Ltd., urethane diacrylate monomer UN-2600 Negami Chemical Industrial Co., Ltd., urethane diacrylate monomer UN-352 Negami Chemical Industrial Co., Ltd., urethane diacrylate monomer UN-333 Negami Chemical Industrial Co., Ltd., urethane diacrylate monomer with polyester skeleton SUA-01: A compound, urethane diacrylate monomer, produced by the method described in Production Example 1A below. SUA-02: A compound, urethane diacrylate monomer, produced by the method described in Production Example 2A below. SUA-03: A compound, urethane diacrylate monomer, produced by the method described in Production Example 3A below. SUA-04: A compound, urethane diacrylate monomer, produced by the method described in Production Example 4A below. SUA-05: A compound, urethane diacrylate monomer, produced by the method described in Production Example 5A below. AH-600 Kyoeisha Chemical Co., Ltd., urethane diacrylate monomer MMD-352: A compound, urethane diacrylate monomer, produced by the method described in Production Example 6A below. Ebecryl 8402 and Ebecryl 230, urethane diacrylate monomers manufactured by Daicel-Allnex Corporation

[0195] [Production Example 1A: Production of SUA-01] In a 1-liter, four-neck flask equipped with a thoroughly dried stirring blade and a thermometer, 222 g (1.00 mol) of IPDI (isophorone diisocyanate), 0.84 g (0.1 wt % based on the total weight of IPDI, PEG-1000, and HEA) of DBTDL (dibutyltin dilaurate), and 0.42 g (0.05 wt % based on the total weight of IPDI, PEG-1000, and HEA) of MEHQ (4-methoxyphenol) were added and stirred until homogeneous. The mixture was then heated to 60°C. Subsequently, 500 g (0.50 mol) of PEG-1000 (molecular weight 1000, manufactured by Toho Chemical Industry Co., Ltd.) was added dropwise over 1 hour. During the addition, the internal temperature rose due to the heat of reaction, so the amount added was controlled to maintain the temperature below 80°C. After the entire amount was added, the reaction temperature was maintained at 80°C and the reaction was continued for 5 hours. Next, the internal temperature of the flask was maintained at 60°C, and 116 g (1.00 mol) of HEA (2-hydroxyethyl acrylate) added to a separate dropping funnel was added dropwise over 1 hour. During the addition, the internal temperature rose due to the heat of reaction, so the amount added was controlled so that it remained below 80°C. After the entire amount was added dropwise, the reaction temperature was maintained at 80°C, and the reaction was carried out for 5 hours. The reaction progress was monitored by HPLC analysis to confirm the end point of the reaction. The product was discharged from the reactor, yielding 820 g of urethane acrylate (SUA-01). The viscosity at 40°C was 31,000 mPa·s.

[0196] [Production Example 2A: Production of SUA-02] In a 1-liter, four-neck flask equipped with a thoroughly dried stirring blade and a thermometer, 222 g (1.00 mol) of IPDI (isophorone diisocyanate), 0.84 g (0.1 wt % based on the total weight of IPDI, EXCENOL 1020, and HEA) of DBTDL (dibutyltin dilaurate), and 0.42 g (0.05 wt % based on the total weight of IPDI, EXCENOL 1020, and HEA) of MEHQ (4-methoxyphenol) were added and stirred until homogeneous. The mixture was then heated to 60°C. Subsequently, 500 g (0.50 mol) of EXCENOL 1020 (molecular weight 1000, manufactured by AGC Chemicals) was added dropwise over 1 hour. During the addition, the internal temperature rose due to the heat of reaction, so the amount added was controlled to keep the temperature below 80°C. After the entire amount was added, the reaction temperature was maintained at 80°C and the reaction was continued for 5 hours. Next, the internal temperature of the flask was maintained at 60°C, and 116 g (1.00 mol) of HEA (2-hydroxyethyl acrylate) added to a separate dropping funnel was added dropwise over 1 hour. During the addition, the internal temperature rose due to the heat of reaction, so the amount added was controlled so that it remained below 80°C. After the entire amount was added dropwise, the reaction temperature was maintained at 80°C, and the reaction was carried out for 5 hours. The reaction progress was monitored by HPLC analysis to confirm the end point of the reaction. The product was discharged from the reactor, yielding 820 g of urethane acrylate (SUA-02) represented by the following formula. Its viscosity at 40°C was 27,000 mPa·s.

[0197] [Production Example 3A: Production of SUA-03] In a 1-liter, four-neck flask equipped with a thoroughly dried stirring blade and a thermometer, 222 g (1.00 mol) of IPDI (isophorone diisocyanate), 0.87 g (0.1 wt % based on the total weight of IPDI, PEG-1000, and 4HBA) of DBTDL (dibutyltin dilaurate), and 0.43 g (0.05 wt % based on the total weight of IPDI, PEG-1000, and 4HBA) of MEHQ (4-methoxyphenol) were added and stirred until homogeneous. The mixture was then heated to 60°C. Subsequently, 500 g (0.50 mol) of PEG-1000 (molecular weight 1000, manufactured by Toho Chemical Industry Co., Ltd.) was added dropwise over 1 hour. During the addition, the internal temperature rose due to the heat of reaction, so the amount added was controlled to maintain the temperature below 80°C. After the entire amount was added, the reaction temperature was maintained at 80°C and the reaction was continued for 5 hours. Next, the internal temperature of the flask was maintained at 60°C, and 144 g (1.00 mol) of 4HBA (4-hydroxybutyl acrylate) added to a separate dropping funnel was added dropwise over 1 hour. During the addition, the internal temperature rose due to the heat of reaction, so the amount added was controlled so that the temperature remained below 80°C. After the entire amount was added dropwise, the reaction temperature was maintained at 80°C, and the reaction was carried out for 5 hours. The reaction progress was monitored by HPLC analysis to confirm the end of the reaction. The product was discharged from the reactor, yielding 840 g of urethane acrylate (SUA-03) represented by the following formula. Its viscosity at 40°C was 45,000 mPa·s.

[0198] [Production Example 4A: Production of SUA-04] In a 1-liter, four-neck flask equipped with a thoroughly dried stirring blade and a thermometer, 222 g (1.00 mol) of IPDI (isophorone diisocyanate), 0.87 g (0.1 wt % based on the total weight of IPDI, EXCENOL 1020, and 4HBA) of dibutyltin dilaurate (DBTDL), and 0.43 g (0.05 wt % based on the total weight of IPDI, EXCENOL 1020, and 4HBA) of MEHQ were added and stirred until homogeneous. The mixture was then heated to 60°C. Subsequently, 500 g (0.50 mol) of EXCENOL 1020 (molecular weight 1000, manufactured by AGC Chemicals) was added dropwise over 1 hour. During the addition, the internal temperature rose due to the heat of reaction, so the amount added was controlled to maintain the temperature below 80°C. After the entire amount was added, the reaction temperature was maintained at 80°C and the reaction was continued for 5 hours. Next, the internal temperature of the flask was maintained at 60°C, and 144 g (1.00 mol) of 4HBA (4-hydroxybutyl acrylate) added to a separate dropping funnel was added dropwise over 1 hour. During the addition, the internal temperature rose due to the heat of reaction, so the amount added was controlled so that the temperature remained below 80°C. After the entire amount was added dropwise, the reaction temperature was maintained at 80°C, and the reaction was carried out for 5 hours. The reaction progress was monitored by HPLC analysis to confirm the end of the reaction. The product was discharged from the reactor, yielding 840 g of urethane acrylate (SUA-04) represented by the following formula. Its viscosity at 40°C was 42,000 mPa·s.

[0199] [Production Example 5A: Production of SUA-05] Into a 1-liter four-neck flask equipped with a thoroughly dried stirring blade and a thermometer, 222 g (1.00 mol) of IPDI (isophorone diisocyanate), 0.87 g (0.1 wt % based on the total weight of IPDI, PTMG1000, and 4HBA) of DBTDL (dibutyltin dilaurate), and 0.43 g (0.05 wt % based on the total weight of IPDI, PTMG1000, and 4HBA) of MEHQ (4-methoxyphenol) were added, stirred until homogenous, and then heated to 60°C. Next, 500 g (0.50 mol) of PTMG1000 (molecular weight 1000, manufactured by Mitsubishi Chemical Corporation) was added dropwise over 1 hour. During the addition, the internal temperature rose due to the heat of reaction, so the amount added was controlled so that the temperature remained below 80°C. After the entire amount was added dropwise, the reaction temperature was maintained at 80°C and the reaction was carried out for 5 hours. Next, the internal temperature of the flask was maintained at 60°C, and 144 g (1.00 mol) of 4HBA (4-hydroxybutyl acrylate) added in a separate dropping funnel was added dropwise over 1 hour. During the addition, the internal temperature rose due to the heat of reaction, so the amount added was controlled so that the temperature remained below 80°C. After the entire amount was added dropwise, the reaction temperature was maintained at 80°C and the reaction was carried out for 5 hours. The reaction progress was monitored by HPLC analysis to confirm the end of the reaction. The product was discharged from the reactor, yielding 840 g of urethane acrylate (SUA-05) represented by the following formula. Its viscosity at 40°C was 38,000 mPa·s.

[0200] [Production Example 6A: Production of MMD-352] In a 1-liter, four-necked flask equipped with a thoroughly dried stirring blade and a thermometer, 444 g (2.00 mol) of M-600A (phenyl glycidyl ether acrylate, manufactured by Kyoeisha Chemical Co., Ltd.), 0.63 g of DBTDL (dibutyltin dilaurate), and 0.32 g of MEHQ (4-methoxyphenol) were added and stirred until homogeneous. The mixture was then heated to 60°C. Subsequently, 188 g (1.00 mol) of XDI (m-xylylene diisocyanate) was added dropwise over 1 hour. During the addition, the internal temperature rose due to the heat of reaction, so the amount added was controlled to keep the temperature below 80°C. After the entire amount was added, the reaction temperature was maintained at 80°C and the reaction was carried out for 10 hours. The reaction progress was monitored by HPLC analysis to confirm the end point of the reaction. The product was discharged from the reactor, yielding 600 g of urethane diacrylate monomer (MMD-352). The viscosity at 65°C was 6210 mPa·s.

[0201] <Other (meth)acrylic monomers> ((Meth)acrylic monomer having two (meth)acryloyloxy groups and no urethane bond) 4EG Dimethacrylate monomer manufactured by Kyoeisha Chemical Co., Ltd. [ka]

[0202] <(Meth)acrylic Monomer (B) Having One Acryloyl Group> The structures of the (meth)acrylic monomers (B) having one acryloyl group shown in Tables 1 to 3 are as follows:

[0203] [ka]

[0204] PO-A manufactured by Kyoeisha Chemical Co., Ltd. P2H-A Kyoeisha Chemical Co., Ltd. POBA manufactured by Kyoeisha Chemical Co., Ltd. M-600A Kyoeisha Chemical Co., Ltd. M110, M111, M113 manufactured by Toagosei Co., Ltd. HRD01 Manufactured by Nisshoku Techno Fine Chemical Co., Ltd. BZ Kyoeisha Chemical Co., Ltd. PO Kyoeisha Chemical Co., Ltd. LA Kyoeisha Chemical Co., Ltd. THF-A manufactured by Kyoeisha Chemical Co., Ltd.

[0205] <Photopolymerization initiator> The structures of the photopolymerization initiators listed in Tables 1 to 3 are as follows:

[0206] [ka]

[0207] OmniradTPO is manufactured by IGMresins. Omnirad819 is manufactured by IGMresins.

[0208] As shown in Tables 1 to 3, in the examples containing a (meth)acrylic monomer component and a photopolymerization initiator, in which the adhesive strength of the cured product was 1.5 N or less and the breaking elongation of the cured product was 20% or more, a cured product with excellent breaking elongation and reduced adhesive strength was obtained. Furthermore, the cured products of the examples, which contained a (meth)acrylic monomer component and a photopolymerization initiator, and in which the adhesive strength of the cured product was 1.5 N or less and the breaking elongation of the cured product was 20% or more, exhibited high shape recovery in the shape recovery test, and the occurrence of cracks and fissures was suppressed. Furthermore, in examples containing a (meth)acrylic monomer component and a photopolymerization initiator, in which the adhesive strength of the cured product was 1.5 N or less and the impact absorption of the cured product was 20% or more and 80% or less, a cured product with excellent breaking elongation and suppressed adhesive strength was obtained. Furthermore, in the examples containing a (meth)acrylic monomer component and a photopolymerization initiator, the adhesive strength of the cured product was 1.5 N or less, and the impact absorption of the cured product was 20% or more and 80% or less, the shape recovery test showed high shape recovery and the occurrence of cracks and fissures was suppressed. Furthermore, in the examples containing the (meth)acrylic monomer component (A) having two (meth)acryloyl groups and (B) having one (meth)acryloyl group, a cured product with excellent breaking elongation and suppressed adhesive strength was obtained. Furthermore, in the cured products of the examples which contained a (meth)acrylic monomer component and a photopolymerization initiator, and in which the adhesive strength of the cured product was 1.5 N or less and the impact absorption of the cured product was 20% or more and 80% or less, the shape recovery was high in the shape recovery test, and the occurrence of cracks and fissures was suppressed. On the other hand, the adhesive strength of the cured product obtained in Comparative Example 1A was not suppressed. The cured products obtained in Comparative Examples 2A and 3A had poor elongation at break. Furthermore, the cured products of Comparative Examples 1A to 3A showed cracks and fissures in the shape recovery test.

[0209] Furthermore, it was found that Examples 40A and 41A, in which the (a) (meth)acrylic monomer (A) contained a (meth)acrylic monomer (A-1) having a molecular weight per (meth)acryloyl group of 300 g / mol or more and 600 g / mol or less and a (meth)acrylic monomer (A-2) having a molecular weight per (meth)acryloyl group of more than 600 g / mol and 15,000 g / mol or less, recovered to their original shape in 0 second or more and less than 1 second after stress release, and had excellent shape recovery properties. (b) Examples 7A, 12A, 14A, 15A and 18A, which contain a (meth)acrylic monomer (B-1) having two aromatic rings and a (meth)acrylic monomer (B-2) having one aromatic ring, recovered to their original shape in 0 seconds or more and less than 1 second after stress release, and were found to have excellent shape recovery properties. Examples 38A and 39A, which satisfied both conditions (a) and (b), recovered to their original shapes in 0 seconds or more and less than 1 second after stress release, demonstrating excellent shape recovery properties.

[0210] Example B Example B is an example for more specifically explaining the second embodiment of the present disclosure. <Preparation of Photocurable Composition> [Examples 1B to 35B, Comparative Example 2B] Photocurable compositions were obtained by mixing the components shown in Tables 4 to 7 below. The viscosities of the respective photocurable compositions are shown in Tables 4 to 7. The viscosity was measured in the same manner as described above.

[0211] [Comparative example 1B] Gingiva Mask (manufactured by NextDent) was used as the photocurable composition.

[0212] <Evaluation> The obtained test pieces were subjected to the following measurements and evaluations. The results are shown in Tables 4 to 7.

[0213] (breaking elongation) The obtained photocurable composition was printed using a 3D printer (Kulzer, Cara Print 4.0) with visible light at a wavelength of 405 nm and an illuminance of 8.0 mJ / cm. 2 Under the conditions above, a dumbbell-shaped test piece conforming to ISO 37-2 was shaped to obtain a shaped object (layer width 50 μm). The obtained shaped object was irradiated with ultraviolet light of 365 nm wavelength at 10 J / cm. 2 The photopolymerization product was cured by irradiation under the conditions of (a) to (c). The breaking elongation of the obtained stereolithography object (hereinafter referred to as "test piece") was measured in accordance with ISO 37: 2017. These measurements were performed using a tensile testing device (manufactured by Shimadzu Corporation) at a tensile speed of 500±50 mm / min.

[0214] (Shore A hardness) The obtained photocurable composition was printed using a 3D printer (Kulzer, Cara Print 4.0) with visible light at a wavelength of 405 nm and an illuminance of 8.0 mJ / cm. 2 Under these conditions, a 25mm long x 25mm wide x 6mm thick object (layer width 50μm) was obtained. The obtained object was exposed to ultraviolet light with a wavelength of 365nm at 10J / cm. 2 The object was irradiated under the conditions of (a) to completely cure the object, thereby obtaining a photo-fabricated object (i.e., a cured object). The Shore A hardness of the obtained stereolithography object (hereinafter referred to as "test piece") was measured in accordance with ISO 7619-1: 2010. The hardness was measured using a durometer-type hardness tester (manufactured by Mitutoyo Corporation), and the value measured 15 seconds after penetration was taken as the Shore A hardness value.

[0215] (Adhesive strength) The obtained photocurable composition was printed using a 3D printer (Kulzer, Cara Print 4.0) with visible light at a wavelength of 405 nm and an illuminance of 8.0 mJ / cm. 2 Under these conditions, a 20mm long x 20mm wide x 2mm thick object (layer width 50μm) was obtained. The obtained object was exposed to ultraviolet light with a wavelength of 365nm at 10J / cm. 2 The object was irradiated under the conditions of (a) to (c) and completely cured, thereby obtaining a photo-fabricated object. The resulting stereolithography (hereinafter referred to as "test piece") was attached to a sample stage so as not to sag. Next, an aluminum probe with a contact area of ​​10 mm length × 10 mm width was brought into contact with the 20 mm length × 20 mm width surface of the test piece, and a pressure of 0.98 ± 0.01 N / cm 2 The contact load was maintained for 1.0±0.1 seconds. Thereafter, the probe was peeled off from the contact surface in the vertical direction at a speed of 5±0.5 mm per second using a tensile testing device (Shimadzu Corporation). The maximum load required to peel off the probe from the contact surface was determined and used as the adhesive strength (unit: N) of the cured product.

[0216] [Table 4]

[0217] [Table 5]

[0218] [Table 6]

[0219] [Table 7]

[0220] In Tables 4 to 7, the numbers in the "Composition" column for each Example and Comparative Example are shown in parts by mass. In Tables 4 to 7, the notation "AE+B (A and B are arbitrary numbers)" means A x 10 B means. In Tables 4 to 7, the details of each component are as follows:

[0221] <(Meth)acrylic Monomer (A) Having Two (Meth)acryloyloxy Groups and Two Urethane Bonds> The structures of the (meth)acrylic monomers (A) having two (meth)acryloyloxy groups and two urethane bonds shown in Tables 4 to 7 are as follows:

[0222] [ka]

[0223] UA-160TM Shin-Nakamura Chemical Co., Ltd., urethane diacrylate monomer with polyether skeleton UA-122P Shin-Nakamura Chemical Co., Ltd., urethane diacrylate monomer with polyether skeleton UN-6305 Negami Chemical Industrial Co., Ltd., urethane diacrylate monomer with polyether structure UN-2700 Negami Chemical Industrial Co., Ltd., urethane diacrylate monomer UN-2600 Negami Chemical Industrial Co., Ltd., urethane diacrylate monomer UN-352 Negami Chemical Industrial Co., Ltd., urethane diacrylate monomer AH-600 Kyoeisha Chemical Co., Ltd., urethane diacrylate monomer MMD-352: A compound, urethane diacrylate monomer, produced by the method described in Production Example 1B below. Ebecryl 8402 and Ebecryl 230, urethane diacrylate monomers manufactured by Daicel-Allnex Corporation Ebecryl4859, manufactured by Daicel-Allnex Corporation, urethane diacrylate monomer ABE-300 Shin-Nakamura Chemical Co., Ltd., ethoxylated bisphenol A diacrylate

[0224] [Production Example 1B: Production of MMD-352] In a 1-liter, four-necked flask equipped with a thoroughly dried stirring blade and a thermometer, 444 g (2.00 mol) of M-600A (phenyl glycidyl ether acrylate, manufactured by Kyoeisha Chemical Co., Ltd.), 0.63 g of DBTDL (dibutyltin dilaurate), and 0.32 g of MEHQ (4-methoxyphenol) were added and stirred until homogeneous. The mixture was then heated to 60°C. Subsequently, 188 g (1.00 mol) of XDI (m-xylylene diisocyanate) was added dropwise over 1 hour. During the addition, the internal temperature rose due to the heat of reaction, so the amount added was controlled to keep the temperature below 80°C. After the entire amount was added, the reaction temperature was maintained at 80°C and the reaction was carried out for 10 hours. The reaction progress was monitored by HPLC analysis to confirm the end point of the reaction. The product was discharged from the reactor, yielding 600 g of urethane diacrylate monomer (MMD-352). The viscosity at 65°C was 6210 mPa·s.

[0225] <(Meth)acrylic Monomer (B) Having One Acryloyl Group> The structures of the (meth)acrylic monomers (B) having one acryloyl group listed in Tables 4 to 7 are as follows:

[0226] [ka]

[0227] PO-A manufactured by Kyoeisha Chemical Co., Ltd. P2H-A Kyoeisha Chemical Co., Ltd. POBA manufactured by Kyoeisha Chemical Co., Ltd. M-600A Kyoeisha Chemical Co., Ltd. M110, M111, M113 manufactured by Toagosei Co., Ltd. HRD01 Manufactured by Nisshoku Techno Fine Chemical Co., Ltd. BZ Kyoeisha Chemical Co., Ltd. PO Kyoeisha Chemical Co., Ltd. LA Kyoeisha Chemical Co., Ltd.

[0228] <Photopolymerization initiator> The structures of the photopolymerization initiators listed in Tables 4 to 7 are as follows:

[0229] [ka]

[0230] OmniradTPO is manufactured by IGMresins Corporation. Omnirad819 is manufactured by IGMresins.

[0231] As shown in Tables 4 to 7, in the examples, cured products with excellent elongation at break and suppressed adhesive strength were obtained. On the other hand, the adhesive strength of the cured product obtained in Comparative Example 1B was not suppressed.

[0232] <Manufacturing mouthguards> Example 1C Plaster casts of the upper and lower jaws and the occlusion were taken as 3D impression data using a laboratory dental scanner (Kulzer, Cara Scan 4.0). Each 3D impression data was uploaded to CAD design (DENTCA, DENTCAdesign.com). The outline of the mouthguard was designed using the software, with the occlusal surface thickness of the central incisor set to 2.5 mm and the occlusal surface thickness of the second molar set to 1.0 mm (i.e., the occlusal surface thickness of the central incisor was 2.5 times that of the second molar). The software's algorithm automatically calculated the 3D modeling data for the desired upper jaw mouthguard. Using a 3D printer (Kulzer, Cara Print 4.0), the photocurable composition of Example 1A was modeled using the 3D modeling data of the mouth guard obtained above under conditions of a visible light wavelength of 405 nm and a visible light illuminance of 8.0 mJ / cm2, to obtain a model of an upper jaw mouth guard. The obtained mouthguard model was irradiated with ultraviolet light at a wavelength of 365 nm at 10 J / cm2 to completely harden the model, thereby obtaining a mouthguard. When the obtained mouth guard was fitted to the plaster casts of the upper and lower jaws, it fitted with very good compatibility.

[0233] <Comparative example 1C> The same operations as in Example 1C were performed, except that the occlusal surface thickness of the central incisor portion was set to 2.0 mm and the occlusal surface thickness of the second molar portion was set to 2.0 mm (i.e., the occlusal surface thickness of the central incisor portion was set to 1 times the occlusal surface thickness of the second molar portion), and three-dimensional modeling data for the desired mouth guard was obtained by automatic calculation using a software algorithm. Using a 3D printer (Kulzer, Cara Print 4.0), the photocurable composition of Example 1B was modeled using the 3D modeling data of the mouth guard obtained above under conditions of a visible light wavelength of 405 nm and a visible light illuminance of 8.0 mJ / cm2, to obtain a mouth guard model. The obtained mouthguard model was irradiated with ultraviolet light at a wavelength of 365 nm at 10 J / cm2 to completely harden the model, thereby obtaining a mouthguard.

[0234] <Articulator wearing test> The mouth guards manufactured by the methods of Example 1C and Comparative Example 1C were attached to an articulator on which plaster casts of the upper and lower jaws were mounted, and evaluated according to the following criteria. ~Evaluation Criteria~ A: When attached to the articulator, the maxillary mouth guard was able to come into contact with the mandibular central incisor area of ​​the plaster model and the mandibular second molar area of ​​the plaster model without any occlusal adjustment. B: When attached to the articulator, the maxillary mouth guard was in contact with the mandibular second molar area of ​​the plaster model, but a gap occurred between the maxillary mouth guard and the mandibular central incisor area of ​​the plaster model, requiring occlusion adjustment to bring them into contact.

[0235] [Table 8]

[0236] The disclosures of Japanese Patent Application No. 2019-195499 filed on October 28, 2019, Japanese Patent Application No. 2019-195500 filed on October 28, 2019, and Japanese Patent Application No. 2020-071833 filed on April 13, 2020 are incorporated herein by reference in their entirety. All publications, patent applications, and technical standards mentioned in this specification are herein incorporated by reference to the same extent as if each individual publication, patent application, or technical standard was specifically and individually indicated to be incorporated by reference.

Claims

1. Contains a (meth)acrylic monomer component and a photopolymerization initiator, The adhesive strength of the cured product is 1.5 N or less, and the breaking elongation of the cured product is 20% or more, the aromatic ring concentration in the (meth)acrylic monomer component is 0.00100 mol / g or more; The (meth)acrylic monomer component comprises a (meth)acrylic monomer (A) having two (meth)acryloyl groups, a (meth)acrylic monomer (B) having one (meth)acryloyl group; Including, The (meth)acrylic monomer (A) includes a compound represented by the following formula (1): The (meth)acrylic monomer (B) is a compound represented by the following formula (2): the content of the (meth)acrylic monomer (A) is 250 parts by mass to 800 parts by mass relative to 1000 parts by mass of the total content of the (meth)acrylic monomer (A) and the (meth)acrylic monomer (B); the total mass of the (meth)acrylic monomer (A), the (meth)acrylic monomer (B), and the photopolymerization initiator is 70 mass% or more based on the total amount of the photocurable composition; The content of the photopolymerization initiator in the photocurable composition is 0.1% by mass to 10% by mass. A photocurable composition. 【Chemical 1】 In formula (1), R １ and R ２ each independently represents a divalent linking group, R ３ are each independently a methyl group or a hydrogen atom, The R １ represents a group consisting of a divalent chain hydrocarbon group having no substituent, or a group consisting of a divalent chain hydrocarbon group and at least one group selected from the group consisting of a divalent hydrocarbon group having an alicyclic structure, a divalent hydrocarbon group having an aromatic structure, and a divalent group containing a hetero atom, the divalent group containing a heteroatom contains at least one bond selected from the group consisting of a urethane bond and an ether bond, The R ２ is a divalent chain hydrocarbon group having 2 to 6 carbon atoms which may have a substituent. 【Chemistry 2】 In formula (2), R ６ is a monovalent organic group having an aromatic ring structure and having 6 to 20 carbon atoms.

2. Contains a (meth)acrylic monomer component and a photopolymerization initiator, The adhesive strength of the cured product is 1.5 N or less, and the breaking elongation of the cured product is 20% or more, The (meth)acrylic monomer component comprises a (meth)acrylic monomer (A) having two (meth)acryloyl groups, a (meth)acrylic monomer (B) having one (meth)acryloyl group; Including, the (meth)acrylic monomer (A) has a molecular weight per (meth)acryloyl group of 300 g / mol or more; At least one of the (meth)acrylic monomer (A) and the (meth)acrylic monomer (B) has an aromatic group, The (meth)acrylic monomer (A) includes a compound represented by the following formula (1): The (meth)acrylic monomer (B) is a compound represented by the following formula (2): the content of the (meth)acrylic monomer (A) is 250 parts by mass to 800 parts by mass relative to 1000 parts by mass of the total content of the (meth)acrylic monomer (A) and the (meth)acrylic monomer (B); the total mass of the (meth)acrylic monomer (A), the (meth)acrylic monomer (B), and the photopolymerization initiator is 70 mass% or more based on the total amount of the photocurable composition; The content of the photopolymerization initiator in the photocurable composition is 0.1% by mass to 10% by mass. A photocurable composition. 【Chemistry 3】 In formula (1), R １ and R ２ each independently represents a divalent linking group, R ３ are each independently a methyl group or a hydrogen atom, The R １ represents a group consisting of a divalent chain hydrocarbon group having no substituent, or a group consisting of a divalent chain hydrocarbon group and at least one group selected from the group consisting of a divalent hydrocarbon group having an alicyclic structure, a divalent hydrocarbon group having an aromatic structure, and a divalent group containing a hetero atom, The divalent group containing a hetero atom is selected from the group consisting of a urethane bond and an ether bond. at least one bond The R ２ is a divalent chain hydrocarbon group having 2 to 6 carbon atoms which may have a substituent. 【Chemistry 4】 In formula (2), R ６ is a monovalent organic group having an aromatic ring structure and having 6 to 20 carbon atoms.

3. 3. The photocurable composition according to claim 1, wherein the cured product has a breaking elongation of 40% or more.

4. Contains a (meth)acrylic monomer component and a photopolymerization initiator, The adhesive strength of the cured product is 1.5 N or less, and the impact absorption of the cured product is 20% or more and 80% or less, the aromatic ring concentration in the (meth)acrylic monomer component is 0.00100 mol / g or more; The (meth)acrylic monomer component comprises a (meth)acrylic monomer (A) having two (meth)acryloyl groups, a (meth)acrylic monomer (B) having one (meth)acryloyl group; Including, The (meth)acrylic monomer (A) includes a compound represented by the following formula (1): The (meth)acrylic monomer (B) is a compound represented by the following formula (2): the content of the (meth)acrylic monomer (A) is 250 parts by mass to 800 parts by mass relative to 1000 parts by mass of the total content of the (meth)acrylic monomer (A) and the (meth)acrylic monomer (B); the total mass of the (meth)acrylic monomer (A), the (meth)acrylic monomer (B), and the photopolymerization initiator is 70 mass% or more based on the total amount of the photocurable composition; The content of the photopolymerization initiator in the photocurable composition is 0.1% by mass to 10% by mass. A photocurable composition. 【Chemistry 5】 In formula (1), R １ and R ２ each independently represents a divalent linking group, R ３ are each independently a methyl group or a hydrogen atom, The R １ represents a group consisting of a divalent chain hydrocarbon group having no substituent, or a group consisting of a divalent chain hydrocarbon group and at least one group selected from the group consisting of a divalent hydrocarbon group having an alicyclic structure, a divalent hydrocarbon group having an aromatic structure, and a divalent group containing a hetero atom, the divalent group containing a heteroatom contains at least one bond selected from the group consisting of a urethane bond and an ether bond, The R ２ is a divalent chain hydrocarbon group having 2 to 6 carbon atoms which may have a substituent. 【Chemistry 6】 In formula (2), R ６ is a monovalent organic group having an aromatic ring structure and having 6 to 20 carbon atoms.

5. Contains a (meth)acrylic monomer component and a photopolymerization initiator, The adhesive strength of the cured product is 1.5 N or less, and the impact absorption of the cured product is 20% or more and 80% or less, The (meth)acrylic monomer component comprises a (meth)acrylic monomer (A) having two (meth)acryloyl groups, a (meth)acrylic monomer (B) having one (meth)acryloyl group; Including, the (meth)acrylic monomer (A) has a molecular weight per (meth)acryloyl group of 300 g / mol or more; At least one of the (meth)acrylic monomer (A) and the (meth)acrylic monomer (B) has an aromatic group, The (meth)acrylic monomer (A) includes a compound represented by the following formula (1): The (meth)acrylic monomer (B) is a compound represented by the following formula (2): the content of the (meth)acrylic monomer (A) is 250 parts by mass to 800 parts by mass relative to 1000 parts by mass of the total content of the (meth)acrylic monomer (A) and the (meth)acrylic monomer (B); the total mass of the (meth)acrylic monomer (A), the (meth)acrylic monomer (B), and the photopolymerization initiator is 70 mass% or more based on the total amount of the photocurable composition; The content of the photopolymerization initiator in the photocurable composition is 0.1% by mass to 10% by mass. A photocurable composition. 【Chemistry 7】 In formula (1), R １ and R ２ each independently represents a divalent linking group, R ３ are each independently a methyl group or a hydrogen atom, The R １ represents a group consisting of a divalent chain hydrocarbon group having no substituent, or a group consisting of a divalent chain hydrocarbon group and at least one group selected from the group consisting of a divalent hydrocarbon group having an alicyclic structure, a divalent hydrocarbon group having an aromatic structure, and a divalent group containing a hetero atom, the divalent group containing a heteroatom contains at least one bond selected from the group consisting of a urethane bond and an ether bond, The R ２ is a divalent chain hydrocarbon group having 2 to 6 carbon atoms which may have a substituent. 【Chemistry 8】 In formula (2), R ６ is a monovalent organic group having an aromatic ring structure and having 6 to 20 carbon atoms. Photocurable composition.

6. 6. The photocurable composition according to claim 4, wherein the impact absorption of the cured product is from 20% to 70%.

7. 7. The photocurable composition according to claim 4, wherein the cured product has a breaking elongation of 20% or more.

8. Contains a (meth)acrylic monomer component and a photopolymerization initiator, The adhesive strength of the cured product is 1.5 N or less, and the Shore A hardness of the cured product is 97 or less, the aromatic ring concentration in the (meth)acrylic monomer component is 0.00100 mol / g or more; The (meth)acrylic monomer component comprises a (meth)acrylic monomer (A) having two (meth)acryloyl groups, a (meth)acrylic monomer (B) having one (meth)acryloyl group; Including, The (meth)acrylic monomer (A) includes a compound represented by the following formula (1): The (meth)acrylic monomer (B) is a compound represented by the following formula (2): the content of the (meth)acrylic monomer (A) is 250 parts by mass to 800 parts by mass relative to 1000 parts by mass of the total content of the (meth)acrylic monomer (A) and the (meth)acrylic monomer (B); the total mass of the (meth)acrylic monomer (A), the (meth)acrylic monomer (B), and the photopolymerization initiator is 70 mass% or more based on the total amount of the photocurable composition; The content of the photopolymerization initiator in the photocurable composition is 0.1% by mass to 10% by mass. A photocurable composition. 【Chemistry 9】 In formula (1), R １ and R ２ each independently represents a divalent linking group, R ３ are each independently a methyl group or a hydrogen atom, The R １ represents a group consisting of a divalent chain hydrocarbon group having no substituent, or a group consisting of a divalent chain hydrocarbon group and at least one group selected from the group consisting of a divalent hydrocarbon group having an alicyclic structure, a divalent hydrocarbon group having an aromatic structure, and a divalent group containing a hetero atom, The divalent group containing a hetero atom is selected from the group consisting of a urethane bond and an ether bond. at least one bond The R ２ is a divalent chain hydrocarbon group having 2 to 6 carbon atoms which may have a substituent. 【Chemistry 10】 In formula (2), R ６ is a monovalent organic group having an aromatic ring structure and having 6 to 20 carbon atoms.

9. Contains a (meth)acrylic monomer component and a photopolymerization initiator, The adhesive strength of the cured product is 1.5 N or less, and the Shore A hardness of the cured product is 97 or less, The (meth)acrylic monomer component comprises a (meth)acrylic monomer (A) having two (meth)acryloyl groups, a (meth)acrylic monomer (B) having one (meth)acryloyl group; Including, the (meth)acrylic monomer (A) has a molecular weight per (meth)acryloyl group of 300 g / mol or more; At least one of the (meth)acrylic monomer (A) and the (meth)acrylic monomer (B) has an aromatic group, The (meth)acrylic monomer (A) includes a compound represented by the following formula (1): The (meth)acrylic monomer (B) is a compound represented by the following formula (2): the content of the (meth)acrylic monomer (A) is 250 parts by mass to 800 parts by mass relative to 1000 parts by mass of the total content of the (meth)acrylic monomer (A) and the (meth)acrylic monomer (B); the total mass of the (meth)acrylic monomer (A), the (meth)acrylic monomer (B), and the photopolymerization initiator is 70 mass% or more based on the total amount of the photocurable composition; The content of the photopolymerization initiator in the photocurable composition is 0.1% by mass to 10% by mass. A photocurable composition. 【Chemistry 11】 In formula (1), R １ and R ２ each independently represents a divalent linking group, R ３ are each independently a methyl group or a hydrogen atom, The R １ represents a group consisting of a divalent chain hydrocarbon group having no substituent, or a group consisting of a divalent chain hydrocarbon group and at least one group selected from the group consisting of a divalent hydrocarbon group having an alicyclic structure, a divalent hydrocarbon group having an aromatic structure, and a divalent group containing a hetero atom, the divalent group containing a heteroatom contains at least one bond selected from the group consisting of a urethane bond and an ether bond, The R ２ is a divalent chain hydrocarbon group having 2 to 6 carbon atoms which may have a substituent. 【Chemistry 12】 In formula (2), R ６ is a monovalent organic group having an aromatic ring structure and having 6 to 20 carbon atoms. Photocurable composition.

10. 9. The photocurable composition according to claim 1, wherein at least one of the (meth)acrylic monomer (A) and the (meth)acrylic monomer (B) has an aromatic group.

11. The R １ is a divalent chain hydrocarbon group or a group consisting of a divalent chain hydrocarbon group and at least one group selected from the group consisting of a divalent hydrocarbon group having an alicyclic structure, a divalent hydrocarbon group having an aromatic structure, and a divalent group containing a hetero atom, The photocurable composition according to any one of claims 2, 5, and 9, wherein the divalent hydrocarbon group having an aromatic structure is a divalent hydrocarbon group represented by the following formula (1-a): 【Chemistry 13】 (In formula (1-a), * represents a bonding position.)

12. The R １ is a divalent chain hydrocarbon group or a group consisting of a divalent chain hydrocarbon group and at least one group selected from the group consisting of a divalent hydrocarbon group having an alicyclic structure and a divalent group containing a hetero atom.

13. The R １ The photocurable composition according to any one of claims 2, 5, and 9, wherein the divalent group containing a hetero atom in the formula (I) contains at least one bond selected from the group consisting of a urethane bond and an ether bond.

14. The photocurable composition according to any one of claims 2, 5, and 9, which satisfies at least one of the following (a) and (b): (a) The (meth)acrylic monomer (A) comprises a (meth)acrylic monomer (A-1) having a molecular weight per (meth)acryloyl group of 300 g / mol or more and 600 g / mol or less, and a (meth)acrylic monomer (A-2) having a molecular weight per (meth)acryloyl group of more than 600 g / mol and 15,000 g / mol or less. (b) The (meth)acrylic monomer (B) contains a (meth)acrylic monomer (B-1) having two aromatic rings and a (meth)acrylic monomer (B-2) having one aromatic ring.

15. 10. The photocurable composition according to claim 2, wherein the (meth)acrylic monomer (A) has an aromatic ring concentration of 0.0016 mol / g or less.

16. The (meth)acrylic monomer (A) and the (meth)acrylic monomer (B) in the (meth)acrylic monomer component The photocurable composition according to any one of claims 2, 5 and 9, wherein the total content of the monomer (B) and the monomer (C) is 90 mass % or more.

17. Z1 in the following formula β is 1 × 10 ４ ~100 x 10 ４ The photocurable composition according to any one of claims 2, 5 and 9, wherein Z1=X1 / Y1 Formula β X1 (g / mol): molecular weight of (meth)acrylic monomer (A) per (meth)acryloyl group Y1 (mol / g): Aromatic ring concentration in the (meth)acrylic monomer component

18. The photocurable composition according to any one of claims 1 to 17, which has a viscosity of 10 mPa·s to 5000 mPa·s at 25°C and 50 rpm as measured with an E-type viscometer.

19. The photocurable composition according to any one of claims 1 to 18, which is used for stereolithography.

20. The photocurable composition according to any one of claims 1 to 19, which is used for producing a dental product by stereolithography.

21. The photocurable composition according to any one of claims 1 to 20, which is used for producing a mouthpiece, a gingiva mask, or a backing material by stereolithography.

22. A dental product comprising a cured product of the photocurable composition according to any one of claims 1 to 21.

23. 23. The dental product according to claim 22, which is for a mouthpiece, a gingiva mask, or a lining material.

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