Photocurable composition and dental product

Abstract

To provide a photocurable composition which can yield a cured product with the suppressed formation of cracks and breaks and excellent handleability.SOLUTION: A photocurable composition includes a (meth)acrylic monomer component and a photopolymerization initiator, wherein the adhesive force of its cured product is less than or equal to 1.5 N, and the rupture elongation of the cured product is greater than or equal to 20%.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present disclosure relates to a photocurable composition and a dental product.

Background Art

[0002] Conventionally, resins have been used in various applications, and characteristics corresponding to the applications are required. For example, a mouthpiece, which is a dental product, is used for the treatment and correction of temporomandibular joint disorders.

[0003] In recent years, as dental products, dental prostheses, instruments used in the oral cavity (such as mouth guards), and other dental products (such as gingiva masks) are known, and various materials are used according to their respective applications. For example, Patent Document 1 discloses a composition for a mouth guard, which comprises: 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, plant waxes, and animal waxes.

[0004] Patent Document 1: Japanese Patent Application Laid-Open No. 2003-019240

Summary of the Invention

Problems to be Solved by the Invention

[0005] For example, dental products such as sports mouthpieces are sometimes deformed by the use of the products. And, the shape of the deformed product after use may not be restored, and cracks, splits, etc. may occur. Therefore, there is a tendency to demand materials that suppress these. Also, for example, in dental products such as sports mouthpieces, the handleability may be impaired because the adhesiveness of the product is high when using the product.

[0006] Problem A to be solved by the first embodiment of the present disclosure is to provide a photocurable composition in which the occurrence of cracks and fissures is suppressed and a cured product excellent in handleability is obtained, and a dental product having a cured product of this photocurable composition.

[0007] In addition, when using a dental product such as a mouthpiece, discomfort may occur due to some force being applied to the contact surface between the teeth and the dental product. The above discomfort may sometimes appear as discomfort such as pain. The above discomfort is often a problem in the use of dental products and improvement is demanded.

[0008] Problem B to be solved by the second embodiment of the present disclosure is to provide a photocurable composition in which discomfort is suppressed when applied to the human body and a cured product excellent in handleability is obtained, and a dental product having a cured product of this photocurable composition.

Means for Solving the Problems

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

[0010] <1> A photocurable composition containing a (meth)acrylic monomer component and a photoinitiator, wherein the adhesive force of the cured product is 1.5 N or less, and the elongation at break of the cured product is 20% or more. <2> The photocurable composition according to <1>, wherein the elongation at break of the cured product is 40% or more. <3> A photocurable composition containing a (meth)acrylic monomer component and a photoinitiator, wherein the adhesive force of the cured product is 1.5 N or less, and the shock absorbency of the cured product is 20% or more and 80% or less. <4> The photocurable composition according to <3>, wherein the shock absorbency of the cured product is 20% or more and 70% or less. <5> The photocurable composition according to <3> or <4>, wherein the elongation at break of the cured product is 20% or more. <6> A photocurable composition comprising a (meth)acrylic monomer component and a photopolymerization initiator, wherein 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. <7> The photocurable composition according to any one of <1> to <6>, wherein the aromatic ring concentration in the (meth)acrylic monomer component is 0.00100 mol / g or more. <8> The photocurable composition according to any one of <1> to <7>, 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. <9> The photocurable composition according to <8>, wherein at least one of the (meth)acrylic monomer (A) and the (meth)acrylic monomer (B) has an aromatic group. <10> A photocurable composition comprising a (meth)acrylic monomer component and a photopolymerization initiator, 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, 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 photocurable composition according to any one of <8> to <10>, wherein the content of the (meth)acrylic monomer (A) is 250 parts by mass to 800 parts by mass with respect to 1000 parts by mass of the total content of the (meth)acrylic monomer (A) and the (meth)acrylic monomer (B). <12> The photocurable composition according to any one of <8> to <11>, wherein the (meth)acrylic monomer (A) includes a compound represented by the following formula (1).

[0011]

Chemical formula

[0012] (In formula (1), R 1 and R 2 each independently represent a divalent linking group, and R 3 are each independently a methyl group or a hydrogen atom.) <13> The R 1 is a group composed of a divalent chain hydrocarbon group or 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) The photocurable composition according to <12>.

[0013] [Chemical formula]

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

[0015] Specific means for solving the above-mentioned problem A include the following aspects. <1A> A photocurable composition comprising a (meth)acrylic monomer component and a photoinitiator, wherein the cured product has 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 an elongation at break of 40% or more. <3A> A photocurable composition comprising a (meth)acrylic monomer component and a photoinitiator, wherein the cured product has an adhesive strength of 1.5 N or less and an impact absorbency of 20% or more and 80% or less. <4A> The photocurable composition according to <3A>, wherein the cured product has an impact absorbency of 20% or more and 70% or less. <5A> The photocurable composition according to <3A> or <4A>, wherein the cured product has an elongation at break of 20% or more. <6A> The photocurable composition according to any one of <1A> to <5A>, 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. <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 includes a (meth)acrylic monomer (A) having two (meth)acryloyl groups and a (meth)acrylic monomer (B) having one (meth)acryloyl group, 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 with respect to 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% by 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>, wherein the viscosity at 25 °C and 50 rpm measured with an E-type viscometer is 10 mPa·s to 5000 mPa·s. <14A> The photocurable composition according to any one of <1A> to <13A>, which is for stereolithography. <15A> The photocurable composition according to any one of <1A> to <14A>, which is used for producing dental products 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 containing a cured product of the photocurable composition according to any one of <1A> to <16A>. <18> The dental product according to <17>, which is for a mouthpiece or a gingiva mask.

[0016] Specific means for solving the above problem B include the following aspects. <1B> A photocurable composition comprising a (meth)acrylic monomer component and a photopolymerization initiator, wherein the adhesive force of the cured product is 1.5 N or less and the Shore A hardness of the cured product is 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 includes a (meth)acrylic monomer (A) having two (meth)acryloyl groups and a (meth)acrylic monomer (B) having one (meth)acryloyl group, the molecular weight per (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. <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 with respect to a total content of 1000 parts by mass 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% by 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 Shore A hardness of the cured product is 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>, wherein the viscosity at 25°C and 50 rpm measured with an E-type viscometer is 10 mPa·s to 5000 mPa·s. <11B> The photocurable composition according to any one of <1B> to <10B>, which is for stereolithography. <12B> The photocurable composition according to any one of <1B> to <11B>, which is used for producing dental products by stereolithography. <13B> The photocurable composition according to any one of <1B> to <12B>, which is used for producing a mouthpiece or a backing material by stereolithography. <14B> A dental product containing a cured product of the photocurable composition according to any one of <1B> to <13B>. <15B> The dental product according to <14B>, which is a mouthpiece or a backing material.

Advantages of the Invention

[0017] According to the first embodiment of the present disclosure, there is provided a photocurable composition capable of suppressing the occurrence of cracks and fissures and obtaining a cured product excellent in handleability, and a dental product having a cured product of this photocurable composition. A dental product can be provided.

[0018] According to the second embodiment of the present disclosure, there is provided a photocurable composition capable of suppressing discomfort when applied to the human body and obtaining a cured product excellent in handleability, and a dental product having a cured product of this photocurable composition.

Brief Description of the Drawings

[0019]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Modes for Carrying Out the Invention

[0020] In the present disclosure, a numerical range represented by “~” means a range including the numerical values described before and after “~” as the lower limit value and the upper limit value. Further, in the present disclosure, “(meth)acrylic monomer” is a concept including both acrylic monomers and methacrylic monomers. Further, in the present disclosure, “(meth)acryloyloxy group” is a concept including both acryloyloxy groups and methacryloyloxy groups, and when described as “acryloyloxy group” or “methacryloyloxy group”, it refers to each only. In the present disclosure, the "urethane bond" refers to an -NHC(=O)O- bond. In the present disclosure, when referring to the amount of each component in the composition, if there are a plurality of substances corresponding to each component in the composition, unless otherwise specified, it means the total amount of the plurality of substances present in the composition.

[0021] Examples of the photocurable composition of the present disclosure include the following first embodiment and second embodiment.

[0022] ≪Photocurable Composition of the First Embodiment≫ Examples of the photocurable composition of the first embodiment include the following form 1a, form 1b, and form 1c. Each aspect (for example, form 1a) may satisfy the characteristics of other aspects (for example, form 1b and / or form 1c).

[0023] ≪Form 1a≫ The photocurable composition according to form 1a of the first embodiment contains a (meth)acrylic monomer component and a photoinitiator, 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.

[0024] The inventors of the present disclosure focused on increasing the elongation at break of the cured product (hereinafter, also simply referred to as the cured product) obtained by photocuring the photocurable composition for the purpose of suppressing the occurrence of cracks and fissures in the product. As a result of the study by the inventors of the present disclosure on the above points, when increasing the elongation at break of the cured product (hereinafter, also simply referred to as the cured product) obtained by photocuring the photocurable composition, it was found that the adhesive strength of the cured product increases, which is one of the reasons for reducing the handleability. That is, from the viewpoint of obtaining a cured product in which both suppression of cracks and fissures and handleability are achieved, it is important to increase the elongation at break 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 photoinitiator, and when the photocurable composition of the first embodiment is photocured, a cured product excellent in elongation at break and with suppressed adhesive force can be obtained because the adhesive force of the cured product is 1.5 N or less and the elongation at break of the cured product is 20% or more. Thereby, a cured product excellent in suppressing cracks and splits and in handleability can be obtained.

[0026] <Adhesive force of cured product> The adhesive force of the cured product obtained by photocuring the photocurable composition of Form 1a is 1.5 N or less. Thereby, the handleability of the cured product can be improved. From the same viewpoint as above, the adhesive force 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 limitation on the lower limit value of the adhesive force of the cured product, and it may be more than 0 N or may be 0.01 N or more.

[0027] The method for measuring the adhesive force of the cured product is as follows. First, the photocurable composition is irradiated with visible light using a 3D printer to form a shaped article (lamination width: 50 μm) with a vertical dimension of 20 mm × a horizontal dimension of 20 mm × a thickness of 2 mm. The irradiation of visible light using the 3D printer is carried out under the condition that the visible light with a wavelength of 405 nm is irradiated to each layer within the range of 5.0 mJ / cm 2 ~10 mJ / cm 2 to obtain a desired thickness. The shaped article obtained above is irradiated with ultraviolet light with a wavelength of 365 nm under the condition of 10 J / cm 2 to fully cure the shaped article to obtain a cured product. The obtained cured product is used as the measurement object for the adhesive force. The cured product to be measured is placed on a paste sample stage, and an aluminum probe with a contact area of 10 mm in length × 10 mm in width is brought into contact with the 20 mm × 20 mm surface of the cured product, and held for 1.0 ± 0.1 seconds under a contact load of 0.98 ± 0.01 N / cm 2 Subsequently, using a tensile testing apparatus, the probe is peeled off vertically from the contact surface at a speed of 5 mm per second. Then, the maximum load required to peel off the probe from the contact surface is determined and taken as the adhesive strength (unit: N) of the cured product in the present disclosure.

[0028] <Elongation at break of the cured product> The photocurable composition of Form 1a has an elongation at break of the cured product obtained by curing the photocurable composition of 20% or more. Thereby, when an external force is applied to the cured product, the occurrence of breakage (such as cracks, fractures, or splits) can be suppressed. Further, when the elongation at break of the cured product is within the above range, once an external force is applied to the cured product and then the external force is removed, the shape of the cured product can be restored to the shape before the application of the external force (such as improving the restoration speed and suppressing the deformation amount during restoration). Also, when the elongation at break of the cured product is within the above range and the adhesive strength of the cured product is 1.5 N or less, the above restorability can be further improved. Furthermore, when the elongation at break of the cured product is within the above range and the adhesive strength of the cured product is 1.5 N or less, the deformation amount during the above restoration can be more favorably suppressed.

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

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

[0031] In the present disclosure, the elongation at break 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 to obtain a shaped article (lamination width 50 μm). The irradiation of visible light using the above 3D printer is performed by irradiating visible light with a wavelength of 405 nm at 5.0 mJ / cm for each layer 2~10 mJ / cm 2 Irradiate under conditions that result in the desired thickness within the range of 2 . With respect to the shaped article obtained above, irradiate it with ultraviolet light having a wavelength of 365 nm at 10 J / cm 2 under the conditions of 2 to fully cure the shaped article and obtain a cured article. The obtained cured article is made the object of measurement of the elongation at break. Measure the elongation at break of the cured article to be measured under the conditions of a tensile speed of 500 ± 50 mm / min using a tensile testing apparatus in accordance with ISO 37:2017.

[0032] (Hardness of the cured article (Shore A hardness)) As the hardness of the cured article of Form 1a, it is preferably 50 or more. Generally, the lower the hardness of the cured article (i.e., the softer it is), the more likely the adhesive strength is to increase. However, when the hardness of the cured article is 50 or more, the adhesive strength of the cured article can be better suppressed. As the upper limit of the hardness of the cured article, there is no particular limitation, but it may be 99 or less. Also, as described above, generally, the lower the hardness of the cured article (i.e., the softer it is), the more likely the adhesive strength is to increase. However, when the photocurable composition of the first embodiment is used, even if the hardness of the obtained cured article is 90 or less, the adhesive strength of the cured article can be suppressed, and even if it is 80 or less, the adhesive strength of the cured article can be suppressed. In the present disclosure, the hardness of the cured article is measured by the following method. First, irradiate the photocurable composition with visible light using a 3D printer to shape the photocurable composition into a shape having a length of 25 mm, a width of 25 mm, and a thickness of 6 mm to obtain a shaped article (lamination width: 50 μm). The irradiation of visible light using the above 3D printer is performed by irradiating visible light having a wavelength of 405 nm at 5.0 mJ / cm 2 ~10 mJ / cm 2 under conditions that result in the desired thickness within the range of 2 . With respect to the shaped article obtained above, irradiate it with ultraviolet light having a wavelength of 365 nm at 10 J / cm 2 under the conditions of 2 to fully cure the shaped article and obtain a cured article. The obtained cured article is made the object of measurement of 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 photocurable composition of Form 1a preferably has a viscosity of 10 mPa·s to 5000 mPa·s, more preferably 20 mPa·s to 3000 mPa·s, as measured using an E-type viscometer at 25°C and 50 rpm (revolutions per minute). 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 Form 1b contains a (meth)acrylic monomer component and a photoinitiator, and the cured product has an adhesive force of 1.5 N or less and an impact absorbency of 20% or more and 80% or less.

[0035] The inventors of the present disclosure focused on the impact absorbency of the cured product (hereinafter, also simply referred to as the cured product) obtained by photocuring the photocurable composition from the viewpoint of suppressing the occurrence of cracks and fissures in the product. As a result of the study by the inventors of the present disclosure on the above points, it was found that when the impact absorbency of the cured product is increased, the adhesive force of the cured product increases, which is one of the reasons for the deterioration of the handleability.

[0036] The photocurable composition of Form 1b contains a (meth)acrylic monomer component and a photoinitiator, and the cured product has an adhesive force of 1.5 N or less and an impact absorbency of 20% or more and 80% or less. Thus, when the photocurable composition of the first embodiment is photocured, it is possible to obtain a cured product that is excellent in suppressing cracks and fissures and has good handleability.

[0037] In Form 1b, the adhesive strength of the cured product is the same as in the case of Form 1a described above, and the same applies to the preferred embodiments.

[0038] <Shock Absorbency> The shock absorbency of the cured product of Form 1b is 20% or more and 80% or less. When the shock absorbency of the cured product is 20% or more, the occurrence of breakage (such as cracks, fractures, and splits) in the cured product can be suppressed. From the same perspective as above, it is preferable that the shock absorbency of the cured product is 30% or more, and more preferably 40% or more.

[0039] When the shock absorbency of the cured product is 80% or less, the handling property can be maintained by preventing the adhesive strength of the cured product from becoming excessively large. From the same perspective as above, it is preferable that the shock absorbency of the cured product is 70% or less, and more preferably 60% or less.

[0040] When the shock absorbency of the cured product is within the above range and the adhesive strength of the cured product is 1.5 N or less, the resilience can be improved in the same manner as in the case of the elongation at break described above, and the amount of deformation during recovery can also be better suppressed.

[0041] As a method for adjusting the value of shock absorbency, there are a method of adjusting the value of shock absorbency by adjusting the aromatic ring concentration of the (meth)acrylic monomer component, a method of adjusting the value of shock absorbency by adjusting the (meth)acryloyl group concentration (mol / g) of the (meth)acrylic monomer (A) described below, and the like. Details will be described later.

[0042] ~Measurement Method of Shock Absorbency~ The measurement method of the shock absorbency of the cured product in the present disclosure is as follows. First, the photocurable composition is shaped into a 20 mm in length × 20 mm in width × 3 mm in thickness object (lamination width: 50 μm) by irradiating the photocurable composition with visible light using a 3D printer. The irradiation of visible light using the 3D printer is performed by irradiating visible light with a wavelength of 405 nm to each layer under the condition of a desired thickness within the range of 5.0 mJ / cm 2 ~10 mJ / cm 2 . The object obtained above is irradiated with ultraviolet light having a wavelength of 365 nm under the condition of 10 J / cm 2 to fully cure the object, thereby obtaining a cured product. Regarding the obtained cured product, the one held at 37 °C for 15 minutes is used as the measurement target for impact absorbency. The impact absorbency of the cured product in the present disclosure means the degree of decrease in the maximum load measured by a load cell when an iron ball is freely dropped onto the cured product. More specifically, the value of A calculated by the following formula is defined as the impact absorbency (A, unit: %) of the cured product in the present disclosure.

[0043] [Equation]

[0044] In the above formula, A (%) represents the impact absorbency, N0 represents the maximum load measured by the load cell when an iron ball (diameter 16.7 mm, 18.8 g) is freely dropped from a position 50 cm above the load cell to the center of a zirconia plate with a thickness of 1 mm, a length of 30 mm × a width of 30 mm placed on the load cell at 23 °C. N represents the maximum load measured by the load cell when an iron ball (diameter 16.7 mm, 18.8 g) is freely dropped from a position 50 cm above the load cell to the center of a measurement target cured product with a thickness of 3 mm, a length of 20 mm, and a width of 20 mm placed at the center of the above zirconia plate on the load cell at 23 °C.

[0045] <<Form 1c>> The photocurable composition according to Form 1c of the first embodiment contains a (meth)acrylic monomer component and a photoinitiator, and 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. 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 and the like contained in the photocurable composition in Forms 1a, 1b, and 1c in 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. Thereby, the elongation at break of the obtained cured product can be improved. As the (meth)acrylic monomer component, any component containing a (meth)acrylic monomer can be used without 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 includes a (meth)acrylic monomer (A) having two (meth)acryloyl groups and a (meth)acrylic monomer (B) having one (meth)acryloyl group.

[0047] It is preferable that the (meth)acrylic monomer component of the first embodiment has an aromatic group. The (meth)acrylic monomer component in the first embodiment contains an acryloyl group. Generally, since an 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, since the (meth)acrylic monomer component has an aromatic group, the adhesiveness of the resulting cured product can be favorably suppressed based on the hydrophobicity of the aromatic group itself and the π-π interaction between aromatic groups. As a result, even when the photocurable composition of the first embodiment uses a (meth)acrylic monomer containing an acryloyl group that may increase the adhesiveness of the cured product, the adhesiveness of the cured product can be more favorably suppressed.

[0048] Also, generally, when the hygroscopicity of the cured product is high, breakage is likely to occur at the site where the cured product absorbs moisture. In view of the above, since the aromatic group has high hydrophobicity, by using a (meth)acrylic monomer having an aromatic group in the photocurable composition of the first embodiment, the hygroscopicity of the resulting cured product can be reduced, and the elongation at break of the cured product can be favorably improved.

[0049] Also, the shock absorbency can be increased by increasing the aromatic ring concentration, and the shock absorbency can be decreased by keeping the aromatic ring concentration low.

[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. As the upper limit of the aromatic ring concentration in the (meth)acrylic monomer component, from the viewpoint of suppressing yellowing of the cured product, it is preferably 0.010 mol / g or less, and more preferably 0.008 mol / g or less.

[0051] Examples of the aromatic group include a phenyl group, a phenylene group, a naphthyl group, and an anthracene group. Among the above, as the aromatic group, a phenyl group and a phenylene group are preferable.

[0052] ((Meth)acrylic monomer (A) having two (meth)acryloyl groups) In the first embodiment, the (meth)acrylic monomer component preferably contains a (meth)acrylic monomer (A) having two (meth)acryloyl groups. The (meth)acrylic monomer (A) does not have a (meth)acryloyl group other than the two (meth)acryloyl groups. As long as the (meth)acrylic monomer (A) is a (meth)acrylic monomer having two (meth)acryloyl groups, one type may be used, or two or more types may be used. 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. Thereby, the elongation at break of the obtained cured product can be improved. From the viewpoints of the elongation at break and the adhesive strength of the obtained 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.

[0054] By increasing the (meth)acryloyl group equivalent of the (meth)acrylic monomer (A) (that is, increasing the molecular weight of the (meth)acrylic monomer (A)), the impact absorbency can be increased, and by decreasing the (meth)acryloyl group equivalent, the impact absorbency can be decreased. That is, by decreasing the (meth)acryloyl group concentration (mol / g) of the (meth)acrylic monomer (A), the impact absorbency can be increased, and by increasing the (meth)acryloyl group concentration (mol / g) of the (meth)acrylic monomer (A), the impact absorbency can be decreased. This can be achieved.

[0055] From the above viewpoints and the viewpoint of improving the hardness of the obtained 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] (Meth)acrylic monomer (A) preferably contains a compound represented by the following formula (1). Also, (meth)acrylic monomer (A) is preferably a compound represented by the following formula (1).

[0057] [Chemical formula] In formula (1), R 1 and R 2 each independently represent a divalent linking group, and 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] In R 1 of formula (1), the divalent organic group preferably contains a divalent chain hydrocarbon group, and more preferably contains a divalent chain hydrocarbon group and at least one group selected from the group consisting of a divalent hydrocarbon group having a cyclic structure and a divalent group containing a hetero atom. Examples of the above cyclic structure include 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 linear or branched alkylene group.

[0061] In R 1 of formula (1), from the viewpoints of viscosity suppression of the photocurable composition, improvement of the elongation at break of the obtained cured product, and suppression of the adhesive force of the obtained cured product, it preferably contains an oxyalkylene structure and a polyester structure. Also, from the same viewpoints as above, in R1 is preferably a divalent acyclic hydrocarbon group having no substituent.

[0062] R in formula (1) 1 In, the number of carbon atoms of the divalent organic group may be, for example, in the range of 5 to 2500, and is preferably in the range of 5 to 2000.

[0063] R in formula (1) 1 In, the divalent organic group may contain a hetero atom. Examples of the hetero atom include, for example, an oxygen atom, a nitrogen atom and the like.

[0064] R in formula (1) 1 In, examples of the divalent hydrocarbon group having an aromatic structure include an arylene group, an alkylene arylene group, an alkylene arylene alkylene group, an arylene alkylene arylene group and the like.

[0065] R in formula (1) 1 In, 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 cycloeicosylene group, a bicyclohexylene group, a norbornylene group, an isobornylene group, an adamantylene group.

[0066] R in formula (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 viewpoints of reducibility and shock absorbency, R 1is preferably a group composed of a divalent chain hydrocarbon group or 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 heteroatom. R 1 is more preferably a group composed of a divalent chain hydrocarbon group or 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 heteroatom.

[0068] From the viewpoints of restorability and shock absorbency, the divalent hydrocarbon group having an aromatic structure is preferably a divalent hydrocarbon group represented by the following formula (1-a). Also, from the viewpoints 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]

Chemical formula

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

[0071] From the viewpoints of restorability and shock absorbency, R 1 The divalent group containing a heteroatom in is preferably a group containing at least one bond selected from the group consisting of a urethane bond and an ether bond.

[0072] In the above formula (1), each R 2 is preferably an optionally substituted divalent chain hydrocarbon group. R 2 The preferred divalent chain hydrocarbon group as is the same as the preferred divalent chain hydrocarbon group as R 1 However, the divalent chain hydrocarbon group as R 2 has 2 to 6 carbon atoms Preferably, it has 2 to 3 carbon atoms, and more preferably 2 to 3 carbon atoms. Further, R 2 The divalent chain hydrocarbon group as R is preferably a divalent chain hydrocarbon group having 2 to 6 carbon atoms and no substituent, and more preferably 2 to 3 carbon atoms, from the viewpoint of suppressing viscosity.

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

[0074] The molecular weight of the (meth)acrylic monomer (A) preferably has a weight average molecular weight of 600 to 30,000, more preferably 800 to 20,000, and even more preferably 1000 to 5000.

[0075] From the viewpoints of restorability and shock absorbency, 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 (meth)acryloyl group in the (meth)acrylic monomer (A) is preferably 300 g / mol or more. Thereby, the elongation at break of the cured product can be further improved. From the same viewpoints as above, the molecular weight per (meth)acryloyl group in the (meth)acrylic monomer (A) is more preferably 600 g / mol or more. Further, 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 (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. In addition, when the (meth)acrylic monomer (A) contains a plurality of (meth)acrylic monomers, 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. The (meth)acrylic monomer (B) does not have a (meth)acryloyl group other than one (meth)acryloyl group. As long as the (meth)acrylic monomer (B) is an acrylic monomer having one (meth)acryloyl group, one type may be used or two or more types may be used.

[0079] The (meth)acrylic monomer (B) preferably contains a ring structure. Thereby, the hardness of the obtained cured product can be improved, and the adhesiveness of the obtained cured product can be suppressed. As the above ring structure, an aromatic structure and an alicyclic structure are preferable, and an aromatic structure is more preferable. Yes.

[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, more preferably 2 and 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 (2).

[0082]

Chemical formula

[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 3 to 30 carbon atoms and having a ring structure (preferably an aromatic ring structure), and more preferably a monovalent organic group having 6 to 20 carbon atoms and having a ring structure (preferably an aromatic ring structure).

[0085] In formula (2), R 6 may be 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 having 1 to 30 carbon atoms which may have a hetero atom of O or N, and A is a hydrogen atom, a monovalent alicyclic group having 3 to 30 carbon atoms which may have a hetero atom of O or N, or an aryl group having 6 to 30 carbon atoms. * represents a bonding position.

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

[0087] L1 may have a substituent. Preferable examples of the substituent of 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 1 or 2 of 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 having 3 to 20 carbon atoms which may have a hetero atom which is O or N and is represented by A 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 cyclicosyl 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 of 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. Preferred examples of the substituent of A include alkyl groups having 1 to 6 carbon atoms such as methyl group and ethyl group; hydroxy group; alkyl groups having 1 to 6 carbon atoms in which one or two of hydrogen atoms are substituted with hydroxy groups; aryl group; cycloalkyl groups having 3 to 6 carbon atoms such as cyclopentyl group and cyclohexyl group; tolyl group: xylyl group: cumyl group; styryl group: alkoxyphenyl groups such as methoxyphenyl group, ethoxyphenyl group, and propoxyphenyl group.

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

[0092] 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 combine with each other to form a ring. Preferred R 7 and R 8 include monovalent hydrocarbon groups having 1 to 30 carbon atoms which may have a hetero atom which is O or N. The hydrocarbon group may be linear, branched, saturated or unsaturated, and may have a substituent. R 7 and R 8 are preferably having 1 to 20 carbon atoms, and more preferably 1 to 10 carbon atoms.

[0093] R 7 and R 8 Examples of the organic group in include alkyl groups having 1 to 30 carbon atoms which may have a hetero atom which is O or N, such as methyl group, ethyl group, and propyl group. Among the above, it is preferable that either one of R 7 and R 8 is a hydroxyethyl group or a butoxymethyl group, and the other is a hydrogen atom. R 7 and R 8When either one of them 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) when they are bonded to each other to form a ring include the following.

[0095]

Chemical formula

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

[0097] Suitable compounds as the (meth)acrylic monomer (B) include, for example, the compounds used in the examples described later.

[0098] In the photocurable composition of the first embodiment, it is preferable that at least one of the (meth)acrylic monomer (A) and the (meth)acrylic monomer (B) has a ring structure. Thereby, the elongation at break of the obtained cured product can be further improved, and the adhesive strength of the obtained cured product can be suppressed. Examples of the above ring structure include an aromatic group and an alicyclic group.

[0099] In the photocurable composition of the first embodiment, it is preferable that at least one of the (meth)acrylic monomer (A) and the (meth)acrylic monomer (B) has an aromatic group. As described above, by having an aromatic group in at least one of the (meth)acrylic monomer (A) and the (meth)acrylic monomer (B), the adhesive strength of the obtained cured product can be favorably suppressed. In addition, 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 elongation at break of the cured product can be favorably improved.

[0100] In the photocurable composition of the first embodiment, with respect to 1000 parts by mass of the total content of the (meth)acrylic monomer (A) and the (meth)acrylic monomer (B), 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.

[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. Further, 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] In the first embodiment, the (meth)acrylic monomer (A) and (meth)acryloyl (B) can improve the tensile elongation of the cured product and reduce the adhesive force. Therefore, the molecular weight (g / mol) of the (meth)acrylic monomer (A) per (meth)acryloyl group [i.e., the molecular weight of the (meth)acrylic monomer (A) / the number of (meth)acryloyl groups in the (meth)acrylic monomer (A)] and the aromatic ring concentration (mol / g) in the (meth)acrylic monomer component are used. It is preferable that Z in the following formula α is 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): (The molecular weight of the (meth)acrylic monomer (A) per (meth)acryloyl group) - 200 Y (mol / g): ((The aromatic ring concentration (mol / g) in the (meth)acrylic monomer component) - 0.00100

[0104] In the first embodiment, the (meth)acrylic monomer (A) and (meth)acryloyl (B) can improve the tensile elongation of the cured product, reduce the adhesive force, and further improve the resilience. Therefore, the molecular weight (g / mol) of the (meth)acrylic monomer (A) per (meth)acryloyl group and the aromatic ring concentration (mol / g) in the (meth)acrylic monomer component are used. Z1 in the following formula β is 5 × 10 3 ~500 × 10 4 which is preferably the case, and more preferably 1 × 10 4 ~100 × 10 4 which is the case. Also, the upper limit of the numerical values in these ranges is also preferable from the viewpoint of improving the formability (e.g., surface roughness, etc.). The lower limit of the numerical values in these ranges is also preferable from the viewpoint of suppressing yellowing. Z1 = X1 / Y1 Formula β X1 (g / mol): The molecular weight of the (meth)acrylic monomer (A) per (meth)acryloyl group Y1 (mol / g): The 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 the following (b). (a) The (meth)acrylic monomer (A) includes a (meth)acrylic monomer (A-1) having a molecular weight of 300 g / mol or more and 600 g / mol or less per (meth)acryloyl group, and a (meth)acrylic monomer (A-2) having a molecular weight of more than 600 g / mol and 15,000 g / mol or less per (meth)acryloyl group. (b) The (meth)acrylic monomer (B) includes 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 has a good balance of adhesive strength, elongation at break, and impact resistance, and further improves the resilience.

[0107] Examples of the (meth)acrylic monomer (A-1) having a molecular weight of 300 g / mol or more and 600 g / mol or less per (meth)acryloyl group include AH-600 (manufactured by Kyoeisha Chemical Co., Ltd.), MMD-352 described below, and the like. Examples of the (meth)acrylic monomer (A-2) having a molecular weight of more than 600 g / mol and 15,000 g / mol or less per (meth)acryloyl group include UA-160TM (manufactured by Shin-Nakamura Chemical Co., Ltd.), UA-122P (manufactured by Shin-Nakamura Chemical Co., Ltd.), UN-2700 (manufactured by Negami Kogyo Co., Ltd.), UN-2600 (manufactured by Negami Kogyo Co., Ltd.), UN-352 (manufactured by Negami Kogyo Co., Ltd.), Ebecryl8402 (manufactured by Daicel Allnex Co., Ltd.), Ebecryl230 (manufactured by Daicel Allnex Co., Ltd.), and the like.

[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 with respect 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 200 parts by mass ~850 parts by mass, preferably 220 parts by mass to 650 parts by mass, and more preferably 250 parts by mass to 500 parts by mass with respect to 1000 parts by mass of the total content of the (meth)acrylic monomer (A) and the (meth)acrylic monomer (B).

[0110] Note that the photocurable composition of the first embodiment preferably has the content of the (meth)acrylic monomer (A-1) and the (meth)acrylic monomer (A-2) within the above-mentioned range whether it contains only one of the (meth)acrylic monomer (A-1) and the (meth)acrylic monomer (A-2) or both.

[0111] The ratio of the content of the (meth)acrylic monomer (A-1) 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 Nisso Techno Fine Chemical Co., Ltd.), M110 (manufactured by Toagosei Co., Ltd.), and the like.

[0113] The (meth)acrylic monomer (B-2) having one aromatic ring includes, for example, PO-A (manufactured by Kyoeisha Chemical Co., Ltd.), M113 (manufactured by Toagosei 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.), M111 (manufactured by Toagosei Co., Ltd.), and the like.

[0114] The content of the (meth)acrylic monomer (B-1) is preferably 100 to 600 parts by mass, more preferably 150 to 500 parts by mass, and even more preferably 200 to 450 parts by mass with respect 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 to 600 parts by mass, more preferably 150 to 500 parts by mass, and even more preferably 200 to 450 parts by mass with respect to 1000 parts by mass of the total content of the (meth)acrylic monomer (A) and the (meth)acrylic monomer (B). Note that the photocurable composition of the first embodiment preferably has the content of the (meth)acrylic monomer (B-1) and the (meth)acrylic monomer (B-2) within the above-mentioned range whether it contains only one of the (meth)acrylic monomer (B-1) and the (meth)acrylic monomer (B-2) or both.

[0116] The content of the (meth)acrylic monomer (B-1) with respect to the total content of the (meth)acrylic monomer (B-1) and the (meth)acrylic monomer (B-2) is preferably 20% to 80% by mass, more preferably 30% to 70% by mass, and even more preferably 40% 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 above (meth)acrylic monomer (A) and the above (meth)acrylic monomer (B). Examples of other additives include trifunctional (meth)acrylic monomers and the like. Among the above, the trifunctional (meth)acrylic monomer can reduce the adhesive strength of the cured product. On the other hand, since the trifunctional (meth)acrylic monomer may reduce the elongation at break of the cured product, it is preferable to add only a small amount within the range where the elongation at break can be maintained.

[0118] (Photoinitiator) The photocurable composition of the first embodiment contains a photoinitiator. The photoinitiator is not particularly limited as long as it can generate radicals by irradiating light, but it is preferably one that can generate radicals at the wavelength of light used during photofabrication. The wavelength of light used during photofabrication generally includes 365 nm to 500 nm, but is preferably 365 nm to 430 nm in practical use, and more preferably 365 nm to 420 nm.

[0119] Examples of photoinitiators that can generate radicals at the wavelength of light used during photofabrication include alkylphenone-based compounds, acylphosphine oxide-based compounds, titanocene-based compounds, oxime ester-based compounds, benzoin-based compounds, acetophenone-based compounds, benzophenone-based compounds, thioxanthone-based compounds, α-acyloxime ester-based compounds, phenylglyoxylate-based compounds, benzyl-based compounds, azo-based compounds, diphenylsulfide-based compounds, organic dye-based compounds, iron-phthalocyanine-based compounds, benzoin ether-based compounds, anthraquinone-based compounds, and the like. Among these, from the viewpoint of reactivity and the like, alkylphenone-based compounds and acylphosphine oxide-based compounds are preferable.

[0120] Examples of alkylphenone compounds include 1-hydroxy-cyclohexyl-phenyl-ketone (Omnirad 184: manufactured by IGM resins). Examples of acylphosphine oxide compounds include bis(2,4,6-trimethylbenzoyl)-phenylphosphine oxide (Omnirad 819: manufactured by IGM resins), 2,4,6-trimethylbenzoyl-diphenyl-phosphine oxide (Omnirad TPO: manufactured by IGM resins).

[0121] The photocurable composition of the first embodiment may contain only one kind of photoinitiator or may contain two or more kinds. The content of the photoinitiator in the photocurable composition of the first embodiment (total content in the case of two or more kinds) 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 components> 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 photoinitiator, if necessary. When the photocurable composition contains the other components, the total mass of the (meth)acrylic monomer (A), the (meth)acrylic monomer (B), and the photoinitiator is preferably 30% by mass or more, more preferably 50% by mass or more, still more preferably 70% by mass or more, further preferably 80% by mass or more, even 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 the other components include monomers other than the (meth)acrylic monomer (A) and the (meth)acrylic monomer (B). When the photocurable composition contains a monomer other than the (meth)acrylic monomer (A) and the (meth)acrylic monomer (B) as other components, the content of the monomer as other components is preferably 50% by mass or less, more preferably 30% by mass or less, still more preferably 20% by mass or less, and particularly preferably 10% by mass or less with respect to the total of the (meth)acrylic monomer (A) and the (meth)acrylic monomer (B). 。

[0124] Examples of other components include colorants, coupling agents such as silane coupling agents (e.g., 3-acryloxypropyltrimethoxysilane), rubber agents, ion trap agents, ion exchangers, leveling agents, plasticizers, additives such as defoaming agents, and thermal polymerization initiators. When the photocurable composition of the first embodiment contains a thermal polymerization initiator, combined use of photocuring and thermosetting becomes possible. Examples of the thermal polymerization initiator include thermal radical generators, amine compounds, and the like.

[0125] The method for preparing the photocurable composition of the first embodiment is not particularly limited, and examples include a method of mixing the (meth)acrylic monomer (A), 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 includes means such as dissolution by ultrasonic waves, a two-arm stirrer, a roll kneader, a twin-screw extruder, a ball mill kneader, and a planetary stirrer. The photocurable composition of the present embodiment may be prepared by filtering with a filter to remove impurities and further performing a vacuum degassing treatment after mixing the components.

[0126] ≪Cured product≫ The method of performing photocuring using the photocurable composition of the first embodiment is not particularly limited, and any known method and apparatus can be used. For example, a method of manufacturing a cured product having a desired shape by repeatedly performing a step of forming a thin film composed of the photocurable composition of the first embodiment and a step of irradiating the thin film with light to obtain a cured layer a plurality of times to laminate a plurality of cured layers can be mentioned. The obtained cured product may be used as it is, or may be used after performing post-curing such as light irradiation and heating to improve its mechanical properties, shape stability, etc.

[0127] <Stereolithography> The photocurable composition of the first embodiment is preferably for stereolithography. Among them, the photocurable composition of the first embodiment can be suitably used for a shaping method using a 3D printer. In the present disclosure, "stereolithography" is one of the three-dimensional shaping methods using a 3D printer.

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

[0129] Examples of the SLA method include a method of obtaining a three-dimensional shaped object by irradiating a spot-shaped ultraviolet laser beam onto the photocurable composition. When manufacturing dental products or the like by the SLA method, for example, the photocurable composition of the present embodiment is stored in a container, and a spot-shaped ultraviolet laser beam is selectively irradiated onto the liquid surface of the photocurable composition so that a desired pattern can be obtained, and the photocurable composition is cured to form a cured layer having a desired thickness on the shaping table. Next, the shaping table is lowered, and a single layer of liquid photocurable composition is supplied onto the cured layer and cured in the same manner, and the lamination operation of obtaining continuous cured layers may be repeated. Thereby, dental products or the like can be manufactured.

[0130] As a DLP method, there is a method of obtaining a three-dimensional object by irradiating a photosensitive composition with planar light. Regarding the method of obtaining a three-dimensional object by the DLP method, for example, the descriptions in Japanese Patent No. 5111880 and Japanese Patent No. 5235056 can be appropriately referred to. When producing dental products or the like by 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, a low-pressure mercury lamp, or an LED is used as a light source, and between the light source and the shaping surface of the photosensitive composition, A planar drawing mask in which a plurality of digital micromirror shutters are arranged in a plane is arranged, and light is irradiated onto the shaping surface of the photosensitive composition through the planar drawing mask to sequentially laminate cured layers having a predetermined shape pattern. Thereby, dental products and the like can be produced.

[0131] As an inkjet method, there is a method of continuously discharging droplets of a photosensitive composition from an inkjet nozzle onto a substrate and irradiating the droplets adhering to the substrate with light to obtain a three-dimensional object. When producing dental products or the like by the inkjet method, for example, while scanning a head equipped with an inkjet nozzle and a light source in a plane, the photosensitive composition is discharged from the inkjet nozzle onto a substrate, and the discharged photosensitive composition is irradiated with light to form a cured layer. These operations are repeated to sequentially laminate the cured layers. Thereby, dental products and the like can be produced.

[0132] ≪Dental Products≫ The photosensitive composition of the first embodiment is suitably used for producing dental products by stereolithography. In addition, the photosensitive composition of the first embodiment is suitably used for producing a mouthpiece, a gingiva mask, or a backing material by stereolithography, and is more suitably used for producing a mouthpiece or a gingiva mask.

[0133] The dental product of the first embodiment preferably contains a cured product of the photosensitive composition of the first embodiment. The dental product containing the cured product of the photocurable composition of the first embodiment (i.e., the stereolithography product) is not particularly limited, and can be used for artificial teeth, prostheses, medical instruments used in the oral cavity, models (gingiva masks, etc.), etc. However, instruments or models used in the oral cavity are preferred, and it is more preferred to be used for mouthpieces (especially sports mouthpieces), gingiva masks, or backing materials, and even more preferred to be used for mouthpieces (especially sports mouthpieces) or gingiva masks. It is preferable to use the cured product of the photocurable composition of the first embodiment for at least a part of the dental product. Examples of the instruments used in the oral cavity include sports mouthpieces, mouth guards, mouthpieces for orthodontics, sprints for bite adjustment or temporomandibular joint disorder treatment, and mouthpieces used for the treatment of sleep apnea syndrome. By using the cured product of the photocurable composition of the first embodiment, a medical instrument excellent in the feeling of use when used in the oral cavity and having sufficient strength and hardness can be manufactured.

[0134] <Method for manufacturing a mouth guard and a mouth guard> When the dental product of the first embodiment is a mouth guard, the mouth guard 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 part is 1.5 times or more the thickness of the occlusal surface of the second molar part, and it is preferable to manufacture the mouth guard by stereolithography. The mouth guard in the first embodiment is a stereolithography product, and it is preferable that the thickness of the occlusal surface of the central incisor part is 1.5 times or more the thickness of the occlusal surface of the second molar part.

[0135] Conventionally, the production of a mouth guard using a commercially available mouth guard sheet and a suction molding machine This was generally the case. In this case, the thickness of the occlusal surface of the mouse guard tended to be uniform, and a lot of time was required for adjusting the occlusal surface. Also, although it is possible to adjust the thickness by arranging multiple sheets of the sheet at a specific site, setting the conditions for manufacturing the mouse guard is difficult, and the skills of the operator and a lot of time are required.

[0136] In the first embodiment, when manufacturing a mouse guard with a 3D printer using a photocurable composition, in the three-dimensional image data of the mouse guard, the thickness of the occlusal surface of the central incisor part is preferably set to 1.5 times or more and 5 times or less, more preferably 2 times or more and 4 times or less, compared to the thickness of the occlusal surface of the second molar part, and CAD design is performed. By manufacturing the mouse guard by stereolithography using a 3D printer, adjustment of the occlusal surface becomes unnecessary or simple, and it becomes possible to significantly shorten the manufacturing time of the mouse guard.

[0137] The central incisor part of the mouse guard is the part on the mouse guard corresponding to the central incisor of the tooth, and is the part on the mouse guard that contacts the central incisor when the mouse guard is worn. The second molar part of the mouse guard is the part on the mouse guard corresponding to the second molar of the tooth, and is the part on the mouse guard that contacts the second molar when the mouse guard is worn. Also, there are two central incisor parts and two second molar parts on the upper jaw and the lower jaw respectively (that is, a total of four on the upper jaw and the lower jaw respectively). Among the above-mentioned central incisor parts and second molar parts, in at least one central incisor part and second molar part, the thickness of the occlusal surface of the central incisor part may be 1.5 times or more the thickness of the occlusal surface of the second molar part, and in all central incisor parts and second molar parts, the thickness of the occlusal surface of the central incisor part may be 1.5 times or more the thickness of the occlusal surface of the second molar part, and the average value of the thicknesses of the occlusal surfaces of all central incisor parts may be 1.5 times or more the average value of the thicknesses of the occlusal surfaces of all second molar parts. When the thickness of the occlusal surface of the central incisor part is 1.5 times or more the thickness of the occlusal surface of the second molar part, when occluding, it becomes easy to bring the central incisor into contact with the mouse guard, so significant occlusal adjustment is not required. In addition, when the thickness of the occlusal surface of the central incisor part is 5 times or less the thickness of the occlusal surface of the second molar part, it becomes easy to bring the second molar into contact with the mouth guard, so that significant occlusal adjustment is not required.

[0138] In addition, the thickness of the occlusal surface of the second molar part is preferably 0.2 mm to 5 mm, and more preferably 0.5 mm to 4 mm. When the thickness of the occlusal surface of the second molar part is 0.2 mm or more, the strength of the mouth guard can be maintained well. In addition, when the thickness of the occlusal surface of the second molar part is 5 mm or less, the degree of opening can be suppressed, and it is possible to suppress the wearer from feeling uncomfortable.

[0139] The thickness of the occlusal surface refers to the thickness of the mouth guard on the occlusal surface of a specific tooth when the mouth guard is worn. Specifically, when wearing the mouth guard, among the distances between the surface in contact with the tip of the tooth and the opposing surface opposing the surface in contact with the tip of the tooth in the tooth part of the mouth guard, which is the part in contact with the teeth, it means the shortest distance. In other words, the thickness of the occlusal surface means the thickness of the thinnest part among the parts of the mouth guard that are bitten and tightened between the teeth when the mouth guard is worn. The opposing surface is a surface of the mouth guard that opposes the surface in contact with the tip of the tooth.

[0140] FIG. 1 is a view showing the appearance of an upper jaw mouth guard according to an embodiment of the present disclosure. As shown in FIG. 1, an upper jaw mouth guard 10 according to an embodiment of the present disclosure includes a second molar part 1 that guards the second molar on the upper jaw side and a central incisor part 2 that guards the central incisor on the upper jaw side. FIG. 2 is a view showing the thickness of the upper jaw mouth guard on the occlusal surface (flat type) of the central incisor part. FIG. 3 is a view showing the thickness of the upper jaw mouth guard on the occlusal surface (non-flat type) of the central incisor part. In addition, when the occlusal surface is flat, the occlusal surface is referred to as the occlusal surface (flat type). When the occlusal surface is not flat, the occlusal surface is referred to as the occlusal surface (non-flat type).

[0141] For example, as shown in FIGS. 2 and 3, the thickness 5 of the occlusal surface of the central incisor part is the shortest distance among the distances between the surface 3 in contact with the tip of the central incisor and the opposing surface 4 opposing the surface 3 in contact with the tip of the central incisor in the central incisor part of the upper jaw mouth guard 10, which is the part in contact with the central incisor when wearing the upper jaw mouth guard 10.

[0142] FIG. 4 is a diagram showing the thickness of the upper jaw mouth guard on the occlusal surface (flat type) of the second molar part. FIG. 5 is a diagram showing the thickness of the upper jaw mouth guard on the occlusal surface (non-flat type) of the second molar part. For example, as shown in FIGS. 4 and 5, the thickness 8 of the occlusal surface of the second molar part is the shortest distance among the distances between the surface 6 in contact with the tip of the second molar and the opposing surface 7 opposing the surface 6 in contact with the tip of the second molar in the second molar part of the upper jaw mouth guard 10, which is the part in contact with the second molar when wearing the upper jaw mouth guard 10.

[0143] Furthermore, the mouth guard produced by a 3D printer using the method of the first embodiment can freely change its thickness in the CAD design, and by performing a design such as thinning only the side surface of the molar part, the wearing comfort can be improved.

[0144] The photocurable composition used in the manufacturing method of this mouth guard is not limited to the photocurable composition of the first embodiment, and any photocurable composition can be used.

[0145] The mouth guard produced by the manufacturing method of this mouth guard is an instrument used in the oral cavity and refers to an instrument configured to cover the teeth and the gingival part. The produced mouth guard is not particularly limited, but an upper jaw mouth guard is preferred.

[0146] <<Photocurable Composition of the Second Embodiment>> Examples of the photocurable composition of the second embodiment include the following Form 2a and Form 2b.

[0147] <<Form 2a>> The photocurable composition according to Form 2a of the second embodiment includes a (meth)acrylic monomer component and a photoinitiator, and the cured product has an adhesive strength of 1.5 N or less and a Shore A hardness of 97 or less.

[0148] The inventors of the present disclosure considered that the cause of discomfort when a cured product obtained by photocuring a photocurable composition (hereinafter, also simply referred to as a cured product) is applied to the human body lies in the hardness of the cured product. For example, when the cured product is used as a mouthpiece, a strong biting force is applied to the contact surface between the mouthpiece and the upper and lower teeth through the mouthpiece by tooth occlusion. At this time, if the hardness of the cured product is high, the above-mentioned biting force is more likely to be transmitted to the teeth, so it is considered that discomfort such as pain occurs. On the other hand, the inventors of the present disclosure found that when the hardness of the cured product is lowered, 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 suppresses discomfort when applied to the human body and has excellent handleability, the hardness of the cured product obtained by photocuring the photocurable composition is specified within a range where discomfort can be suppressed, and it is important to suppress the adhesive strength of the cured product.

[0149] The photocurable composition of Form 2a includes a (meth)acrylic monomer component and a photoinitiator, and the cured product has an adhesive strength of 1.5 N or less and a Shore A hardness of 97 or less. Thus, when the photocurable composition of the second embodiment is photocured, a cured product that suppresses discomfort when applied to the human body and has excellent handleability can be obtained.

[0150] Details such as the preferable range, definition, and measurement method of the adhesion of the cured product of the second embodiment are the same as those of the details of the preferable range, definition, measurement method, etc. described in <Adhesion of the cured product> in the first embodiment described above.

[0151] (Hardness of the cured product (Shore A hardness)) The photocurable composition of Form 2a has a Shore A hardness of the cured product of 97 or less. Since the Shore A hardness of the cured product is 97 or less, discomfort is suppressed when the cured product is applied to the human body. In general, the lower the hardness of the cured product, the easier it is for the adhesion to increase. However, when the photocurable composition of the second embodiment is used, even if the hardness of the obtained cured product is 97 or less, the adhesion of the cured product can be suppressed. From the same viewpoint as above, it is preferable that the Shore A hardness of the cured product is 95 or less, and more preferably 93 or less. Further, the photocurable composition of Form 2a preferably has a hardness of the cured product of 50 or more. In general, the lower the hardness (that is, the softer) the cured product, the easier it is for the adhesion to increase. However, when the hardness of the cured product is 50 or more, the adhesion of the cured product can be suppressed better. From the same viewpoint as above, for the photocurable composition of Form 2a, it is more preferable that the hardness of the cured product is 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 shaped into a shape having a length of 25 mm, a width of 25 mm, and a thickness of 6 mm (lamination width: 50 μm) by irradiating visible light using a 3D printer to obtain a shaped object. The irradiation of visible light using the 3D printer irradiates visible light with a wavelength of 405 nm to each layer within the range of 2 ~10 mJ / cm 2 under the condition of a desired thickness. The shaped object obtained above is irradiated with ultraviolet light having a wavelength of 365 nm at 10 J / cm 2Irradiate under the conditions of to fully cure the shaped article to obtain a cured article. The obtained cured article is the object of hardness measurement. The hardness of the cured article is measured in accordance with ISO 7619-1:2010.

[0152] <Elongation at break of the cured article> For the photocurable composition of the second embodiment, the elongation at break of the cured article obtained by curing the photocurable composition is preferably 10% or more. Thereby, when an external force is applied to the cured article, the occurrence of breakage (such as cracks, fractures, and cracks) can be suppressed. In addition, when the elongation at break of the cured article is within the above range, when the external force is removed after applying the external force to the cured article once, the shape of the cured article can return to the shape before applying the external force (improvement of the recovery speed, suppression of the deformation amount during recovery, etc.). Further, when the elongation at break of the cured article is within the above range and the adhesive force of the cured article is 1.5 N or less, the above-mentioned resilience can be further improved. Furthermore, when the elongation at break of the cured article is within the above range and the adhesive force of the cured article is 1.5 N or less, the deformation amount during the above-mentioned recovery can be better suppressed.

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

[0154] In the present disclosure, the elongation at break of the cured article is measured by the following method. First, the photocurable composition is irradiated with visible light using a 3D printer to shape the photocurable composition into the shape of a dumbbell-shaped test piece conforming to ISO 37-2 to obtain a shaped article (lamination width 50 μm). The irradiation of visible light using the above 3D printer irradiates each layer with visible light having a wavelength of 405 nm at 5.0 mJ / cm 2 ~10 mJ / cm 2 within the range and under the conditions of a desired thickness. For the shaped article obtained above, ultraviolet light with a wavelength of 365 nm is irradiated under the condition of 10 J / cm 2 to obtain a cured product by subjecting the shaped article to final curing. The obtained cured product is made the object of measurement of the elongation at break. The elongation at break of the cured product to be measured is measured using a tensile testing apparatus under the condition of a tensile speed of 500 ± 50 mm / min in accordance with ISO 37:2017.

[0155] Details such as the preferable range of the viscosity and the measurement method of the second embodiment are the same as the details of the preferable range, the measurement method, etc. described in (viscosity) in the above-described first embodiment.

[0156] ≪Embodiment 2b≫ The photocurable composition according to Embodiment 2 of Form 2b contains a (meth)acrylic monomer component and a photopolymerization initiator, 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, 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. Hereinafter, each component and the like contained in the photocurable composition in Form 2a and Form 2b in the second embodiment will be described in detail.

[0157] Details such as specific examples and preferable embodiments of the (meth)acrylic monomer component of the second embodiment are the same as the details of the specific examples and preferable embodiments described in <(meth)acrylic monomer component> in the above-described first embodiment.

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

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

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

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

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

[0163] In the photocurable composition of the second embodiment, with respect to 1000 parts by mass of the total content of the (meth)acrylic monomer (A) and the (meth)acrylic monomer (B), 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.

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

[0165] The photocurable composition of the second embodiment may contain acrylic rubber particles. Details such as specific examples and preferred embodiments of the acrylic rubber particles in the second embodiment are the same as those of the specific examples and preferred embodiments of the acrylic rubber particles that the photocurable composition in the first embodiment can contain.

[0166] In the second embodiment, for (meth)acrylic monomer (A) and (meth)acryloyl (B), it is preferable that Z in formula α described in the above-mentioned first embodiment is within the range shown in the terms of formula α described in the above-mentioned first embodiment.

[0167] In the second embodiment, for (meth)acrylic monomer (A) and (meth)acryloyl (B), it is preferable that Z1 in formula β described in the above-mentioned first embodiment is within the range shown in the terms of formula β described in the above-mentioned first embodiment.

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

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

[0170] (Photoinitiator) The photocurable composition of the second embodiment contains a photoinitiator. Details such as specific examples and preferred embodiments of the photoinitiator in the second embodiment are the same as those of the photoinitiator in the first embodiment described above.

[0171] (Other components) The photocurable composition of the second embodiment may contain one or more other components other than the (meth)acrylic monomer (A), the (meth)acrylic monomer (B), and the photoinitiator, if necessary. Details such as specific examples and preferred embodiments of the other components in the second embodiment are the same as those of the 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 include a method of mixing the (meth)acrylic monomer (A), the (meth)acrylic monomer (B), and the photoinitiator (and other components if necessary). Details are as described in the section of the first embodiment described above.

[0173] ≪Cured product≫ Details such as specific examples and preferred embodiments of the cured product of the second embodiment are the same as those of the cured product described in ≪Cured product≫ of the first embodiment described above.

[0174] (Photofabrication) The photocurable composition of the second embodiment is preferably for stereolithography. Regarding the photocurable composition of the second embodiment being for stereolithography, the preferred embodiments, definitions, and other details are the same as the preferred embodiments, definitions, and other details described in <Stereolithography> of the first embodiment above.

[0175] <3D Printer> Regarding the specific examples, preferred embodiments, and other details of the 3D printer in the second embodiment, they are the same as the specific examples, preferred embodiments, and other details described in <3D Printer> of the first embodiment above.

[0176] ≪Dental Products≫ The photocurable composition of the second embodiment is suitably used for producing dental products by stereolithography. In addition, the photocurable composition of the second embodiment is suitably used for producing a mouthguard, a gingiva mask, or a backing material by stereolithography, and is more suitably used for producing a mouthguard or a gingiva mask.

[0177] <Method for Manufacturing a Mouthguard and Mouthguard> When the dental product of the second embodiment is a mouthguard, the mouthguard is preferably manufactured by stereolithography. Regarding the specific manufacturing method, preferred embodiments, and other details, they are the same as the manufacturing method, preferred embodiments, and other details described in <Method for Manufacturing a Mouthguard and Mouthguard> of the first embodiment above.

Examples

[0178] Hereinafter, an embodiment of the present disclosure will be specifically described by way of 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 in the present disclosure. . <Preparation of Photocurable Composition> 〔Examples 1A to 43A, Comparative Examples 2A to 3A〕 The respective components shown in Tables 1 to 3 below were mixed to obtain a photocurable composition. The viscosities of the respective photocurable compositions are shown in Table 1. The above viscosity was measured by the same method as the above-described method.

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

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

[0182] (Elongation at break) The obtained photocurable composition was shaped into the shape of a dumbbell-shaped test piece conforming to ISO 37-2 using a 3D printer (Kulzer, Cara Print 4.0) under the conditions of a visible light wavelength of 405 nm and a visible light illuminance of 8.0 mJ / cm 2 to obtain a shaped article (lamination width: 50 μm). The obtained shaped article was irradiated with ultraviolet light having a wavelength of 365 nm under the condition of 10 J / cm 2 to be fully cured to obtain a photoformed article (i.e., a cured article). The elongation at break of the obtained photoformed article (hereinafter referred to as "test piece") was measured in accordance with ISO 37:2017. These measurements were performed using a tensile test apparatus (manufactured by Shimadzu Corporation) under the condition of a tensile speed of 500 ± 50 mm / min.

[0183] (Shore A hardness) The obtained photocurable composition was shaped into a size of 25 mm in length × 25 mm in width × 6 mm in thickness using a 3D printer (Kulzer, Cara Print 4.0) under the conditions of a visible light wavelength of 405 nm and a visible light illuminance of 8.0 mJ / cm 2 to obtain a shaped article (lamination width: 50 μm). The obtained shaped article was irradiated with ultraviolet light having a wavelength of 365 nm under the condition of 10 J / cm 2 to be fully cured to obtain a photoformed article (i.e., a cured article). The obtained optically formed object (hereinafter referred to as "test piece") was measured for Shore A hardness in accordance with ISO 7619-1:2010. For the hardness measurement, a durometer-type hardness tester (manufactured by Mitutoyo Corporation) was used, and the value 15 seconds after the needle penetration was taken as the Shore A hardness value.

[0184] (Adhesion) The obtained photocurable composition was shaped into a 20 mm (length) × 20 mm (width) × 2 mm (thickness) object (lamination width: 50 μm) using a 3D printer (Kulzer, Cara Print 4.0) under the conditions of a visible light wavelength of 405 nm and a visible light illuminance of 8.0 mJ / cm 2 . The obtained shaped object was irradiated with ultraviolet light having a wavelength of 365 nm under the condition of 10 J / cm 2 to fully cure the shaped object, thereby obtaining an optically formed object. The obtained optically formed object (hereinafter referred to as "test piece") was attached to the 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 held for 1.0 ± 0.1 seconds at a contact load of 0.98 ± 0.01 N / cm 2 . Thereafter, using a tensile testing apparatus (manufactured by Shimadzu Corporation), the above probe was peeled off vertically from the contact surface at a speed of 5 ± 0.5 mm per second. Then, the maximum load required to peel off the above probe from the contact surface was determined and taken as the adhesion (unit: N) of the cured product.

[0185] (Impact absorbency) The obtained photocurable composition was shaped into a 20 mm (length) × 20 mm (width) × 3 mm (thickness) object (lamination width: 50 μm) using a 3D printer (Kulzer, Cara Print 4.0) under the conditions of a visible light wavelength of 405 nm and a visible light illuminance of 8.0 mJ / cm 2 under the conditions of . The obtained shaped object was irradiated with ultraviolet light having a wavelength of 365 nm under the condition of 10 J / cm 2 to fully cure the shaped object, thereby obtaining an optically formed object. For the obtained optical molded article (hereinafter referred to as "test piece"), the impact absorbency (A (%)) was measured by the method described above. The maximum load was measured using a small universal load cell (LMU-200N, manufactured by IMADA CO., LTD.) connected to a load output machine (ZT Digital Force Gauge, manufactured by IMADA CO., LTD.). The measurement of the maximum load was performed under the temperature condition of 23°C for the test piece within 30 seconds after holding at 37°C for 15 minutes. The free fall of the iron ball was performed in an air atmosphere.

[0186] (Shape recovery test) The obtained photocurable composition was shaped into a molded article (lamination width: 50 μm) with a length of 8 mm, a width of 39 mm, and a thickness of 4 mm using a 3D printer (Kulzer, Cara Print4.0) under the conditions of a visible light wavelength of 405 nm and a visible light illuminance of 8.0 mJ / cm 2 Thereby, a molded article was obtained. The obtained molded article was irradiated with ultraviolet light having a wavelength of 365 nm under the condition of 10 J / cm 2 to fully cure the molded article, thereby obtaining an optical molded article. For the obtained optical molded article (hereinafter referred to as "test piece"), stress was applied to bend the test piece so that both ends in the major axis direction (horizontal axis direction) of the test piece were in contact with each other, and it was held for 10 seconds. Then, the stress was released and the shape change of the test piece was observed, and evaluation was performed according to the following criteria. S: After the stress was released, it recovered to the original shape within 0 seconds or more and less than 1 second. A: After the stress was released, it recovered to the original shape within 1 second or more and less than 3 seconds. B: After the stress was released, it recovered to the original shape within 3 seconds or more and less than 10 seconds. C: At the 10-second time point after the stress was released, it did not recover to the original shape, but cracks and fissures did not occur. D: Cracks occurred in the test piece while the stress was applied for 10 seconds, and the test piece was cracked 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 each comparative example are shown in parts by mass. are. In Tables 1 to 3, the notation "AE + B (where A and B are arbitrary numbers)" means A × 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 structure of each of the (meth)acrylic monomers (A) having two (meth)acryloyloxy groups and two urethane bonds described in Tables 1 to 3 is as follows.

[0192]

Chemical formula

[0193]

Chemical formula

[0194] UA-160TM, manufactured by Shin-Nakamura Chemical Co., Ltd., urethane diacrylate monomer having a polyether backbone UA-122P, manufactured by Shin-Nakamura Chemical Co., Ltd., urethane diacrylate monomer having a polyether backbone UN-6305, manufactured by Negami Industries Co., Ltd., urethane diacrylate monomer having a polyether backbone Urethane diacrylate monomer manufactured by Negami Kogyo Co., Ltd., UN-2700 Urethane diacrylate monomer manufactured by Negami Kogyo Co., Ltd., UN-2600 Urethane diacrylate monomer manufactured by Negami Kogyo Co., Ltd., UN-352 Urethane diacrylate monomer having a polyester backbone, manufactured by Negami Kogyo Co., Ltd., UN-333 Compound manufactured by the method described in Production Example 1A below, urethane diacrylate monomer, SUA-01 Compound manufactured by the method described in Production Example 2A below, urethane diacrylate monomer, SUA-02 Compound manufactured by the method described in Production Example 3A below, urethane diac rylate monomer Compound manufactured by the method described in Production Example 4A below, urethane diacrylate monomer, SUA-04 Compound manufactured by the method described in Production Example 5A below, urethane diacrylate monomer, SUA-05 Urethane diacrylate monomer manufactured by Kyoeisha Chemical Co., Ltd., AH-600 Compound manufactured by the method described in Production Example 6A below, urethane diacrylate monomer, MMD-352 Urethane diacrylate monomers manufactured by Daicel Ornex Co., Ltd., Ebecryl8402 and Ebecryl230

[0195] [Production Example 1A: Production of SUA-01] Into a 1-liter four-necked flask equipped with a well-dried stirring blade and a thermometer, 222 g (1.00 mol) of IPDI (isophorone diisocyanate), 0.84 g of DBTDL (dibutyltin dilaurate) (0.1% by weight based on the total weight of IPDI, PEG-1000 and HEA), and 0.42 g of MEHQ (4-methoxyphenol) (0.05% by weight based on the total weight of IPDI, PEG-1000 and HEA) were added and stirred until uniform, and then the temperature was raised 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. Since the internal temperature rose due to the heat of reaction during the dropwise addition, the dropwise addition rate was controlled so that the temperature remained below 80°C. After the total amount was added dropwise, the reaction temperature was maintained at 80°C and the reaction was carried out for 5 hours. Subsequently, the internal temperature of the flask was maintained at 60°C, and 116 g (1.00 mol) of HEA (2-hydroxyethyl acrylate) added to another dropping funnel was added dropwise over 1 hour. Since the internal temperature rose due to the heat of reaction during the dropwise addition, the dropwise addition rate was controlled so that the temperature remained below 80°C. After the total amount was added dropwise, the reaction temperature was maintained at 80°C and the reaction was carried out for 5 hours. At this time, the progress of the reaction was monitored by HPLC analysis to confirm the end point of the reaction. By discharging the product from the reactor, 820 g of urethane acrylate (SUA-01) was obtained. The viscosity at 40°C was 31000 mPa·s.

[0196] [Production Example 2A: Production of SUA-02] Into a 1-liter four-necked flask equipped with a well-dried stirring blade and a thermometer, 222 g (1.00 mol) of IPDI (isophorone diisocyanate), 0.84 g of DBTDL (dibutyltin dilaurate) (0.1% by weight based on the total weight of IPDI, EXCENOL 1020 and HEA), and 0.42 g of MEHQ (4-methoxyphenol) (0.05% by weight based on the total weight of IPDI, EXCENOL 1020 and HEA) were added and stirred until uniform, and then the temperature was raised 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. Since the internal temperature rose due to the heat of reaction during the dropwise addition, the dropping rate was controlled so that the temperature would be 80 °C or lower. After the total amount was dropped, the reaction temperature was maintained at 80 °C and the reaction was carried out for 5 hours. Subsequently, the internal temperature of the flask was maintained at 60 °C, and 116 g (1.00 mol) of HEA (2-hydroxyethyl acrylate) added to another dropping funnel was added dropwise over 1 hour. Since the internal temperature rose due to the heat of reaction during the dropwise addition, the dropping rate was controlled so that the temperature would be 80 °C or lower. After the total amount was dropped, the reaction temperature was maintained at 80 °C and the reaction was carried out for 5 hours. At this time, the progress of the reaction was monitored by HPLC analysis to confirm the end point of the reaction. By discharging the product from the reactor, 820 g of urethane acrylate (SUA-02) represented by the following formula was obtained. The viscosity at 40 °C was 27000 mPa·s.

[0197] [Production Example 3A: Production of SUA-03] Into a 1-liter four-necked flask equipped with a well-dried stirring blade and a thermometer, 222 g (1.00 mol) of IPDI (isophorone diisocyanate), DBTDL (dibutyltin dilaurate) 0.87 g of dibutyltin dilaurate (0.1% by weight based on the total weight of IPDI, PEG-1000 and 4HBA), and 0.43 g of MEHQ (4-methoxyphenol) (0.05% by weight based on the total weight of IPDI, PEG-1000 and 4HBA) were added and stirred until uniform, and then the temperature was raised 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. Since the internal temperature rose due to the heat of reaction during the addition, the dropping rate was controlled so that the temperature remained below 80°C. After the total amount was added dropwise, the reaction temperature was maintained at 80°C and the reaction was carried out for 5 hours. Subsequently, the internal temperature of the flask was maintained at 60°C, and 144 g (1.00 mol) of 4HBA (4-hydroxybutyl acrylate) added to another dropping funnel was added dropwise over 1 hour. Since the internal temperature rose due to the heat of reaction during the addition, the dropping rate was controlled so that the temperature remained below 80°C. After the total amount was added dropwise, the reaction temperature was maintained at 80°C and the reaction was carried out for 5 hours. At this time, the progress of the reaction was monitored by HPLC analysis to confirm the end point of the reaction. By discharging the product from the reactor, 840 g of urethane acrylate (SUA-03) represented by the following formula was obtained. The viscosity at 40°C was 45000 mPa·s.

[0198] [Production Example 4A: Production of SUA-04] Into a 1-liter four-necked flask equipped with a sufficiently dried stirring blade and a thermometer, 222 g (1.00 mol) of IPDI (isophorone diisocyanate), 0.87 g of DBTDL (dibutyltin dilaurate) (0.1% by weight based on the total weight of IPDI, EXCENOL1020 and 4HBA), and 0.43 g of MEHQ (0.05% by weight based on the total weight of IPDI, EXCENOL1020 and 4HBA) were added and stirred until uniform, and then the temperature was raised to 60°C. Subsequently, 500 g (0.50 mol) of EXCENOL1020 (molecular weight 1000, manufactured by AGC Chemicals) was added dropwise over 1 hour. Since the internal temperature rose due to the heat of reaction during the addition, the dropping rate was controlled so that the temperature remained below 80°C. After the total amount was added dropwise, the reaction temperature was maintained at 80°C and the reaction was carried out for 5 hours. Subsequently, the internal temperature of the flask was maintained at 60°C, and 144 g (1.00 mol) of 4HBA (4-hydroxybutyl acrylate) added to another dropping funnel was added dropwise over 1 hour. Since the internal temperature rose due to the heat of reaction during the dropping, the dropping rate was controlled so that it would be 80°C or lower. After the total amount was dropped, the reaction temperature was maintained at 80°C and the reaction was carried out for 5 hours. At this time, the progress of the reaction was monitored by HPLC analysis to confirm the end point of the reaction. By discharging the product from the reactor, 840 g of urethane acrylate (SUA-04) represented by the following formula was obtained. The viscosity at 40°C was 42000 mPa·s.

[0199] [Production Example 5A: Production of SUA-05] Into a 1-liter four-necked flask equipped with a sufficiently dried stirring blade and a thermometer, 222 g (1.00 mol) of IPDI (isophorone diisocyanate), 0.87 g of DBTDL (dibutyltin dilaurate) (0.1% by weight based on the total weight of IPDI, PTMG1000, and 4HBA), and 0.43 g of MEHQ (4-methoxyphenol) (0.05% by weight based on the total weight of IPDI, PTMG1000, and 4HBA) were added, and after stirring until uniform, the temperature was raised to 60°C. Subsequently, 500 g (0.50 mol) of PTMG1000 (molecular weight 1000, manufactured by Mitsubishi Chemical Corporation) was added dropwise over 1 hour. Since the internal temperature rose due to the heat of reaction during the dropping, the dropping rate was controlled so that it would be 80°C or lower. After the total amount was dropped, the reaction temperature was maintained at 80°C and the reaction was carried out for 5 hours. Subsequently, the internal temperature of the flask was maintained at 60°C, and 144 g (1.00 mol) of 4HBA (4-hydroxybutyl acrylate) added to another dropping funnel was added dropwise over 1 hour. Since the internal temperature rose due to the heat of reaction during the dropping, the dropping rate was controlled so that it would be 80°C or lower. After the total amount was dropped, the reaction temperature was maintained at 80°C and the reaction was carried out for 5 hours. At this time, the progress of the reaction was monitored by HPLC analysis to confirm the end point of the reaction. By discharging the product from the reactor, 840 g of urethane acrylate (SUA-05) represented by the following formula was obtained. The viscosity at 40°C was 38000 mPa·s.

[0200] [Production Example 6A: Production of MMD-352] Into a 1-liter four-necked flask equipped with a sufficiently 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 after stirring until homogeneous, the temperature was raised to 60°C. Subsequently, 188 g (1.00 mol) of XDI (m-xylylene diisocyanate) was added dropwise over 1 hour. Since the internal temperature rose due to the heat of reaction during the dropwise addition, the dropping rate was controlled so that the temperature remained below 80°C. After the total amount was added dropwise, the reaction temperature was maintained at 80°C and the reaction was carried out for 10 hours. At this time, the progress of the reaction was monitored by HPLC analysis to confirm the end point of the reaction. By discharging the product from the reactor, 600 g of urethane diacrylate monomer (MMD-352) was obtained. 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, manufactured by Kyoeisha Chemical Co., Ltd., dimethacrylate monomer [Chemical formula]

[0202] [(Meth)acrylic monomer (B) having one acryloyl group] The structures of each of the (meth)acrylic monomers (B) having one acryloyl group described in Tables 1 to 3 are as follows.

[0203] [Chemical formula]

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

[0205] <Photoinitiator> The structures of each of the photoinitiators described in Tables 1 to 3 are as follows.

[0206]

Chemical formula

[0207] Omnirad TPO is manufactured by IGM resins. Omnirad 819 is manufactured by IGM resins.

[0208] As shown in Tables 1 to 3, in the examples containing a (meth)acrylic monomer component and a photoinitiator, where 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, a cured product with excellent elongation at break and suppressed adhesive strength was obtained. Further, the cured product of the examples containing a (meth)acrylic monomer component and a photoinitiator, where 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, had high shape recovery in the shape recovery test, and the occurrence of cracks and fissures was suppressed. Also, in the examples containing a (meth)acrylic monomer component and a photoinitiator, where the adhesive strength of the cured product is 1.5 N or less and the impact absorbency of the cured product is 20% or more and 80% or less, a cured product with excellent elongation at break and suppressed adhesive strength was obtained. In addition, the cured product of the example containing a (meth)acrylic monomer component and a photopolymerization initiator, having an adhesive strength of the cured product of 1.5 N or less and an impact absorbency of the cured product of 20% or more and 80% or less, had high shape recoverability in the shape recovery test, and the occurrence of cracks and fissures was suppressed. In addition, in the example in which 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, a cured product excellent in elongation at break and having suppressed adhesive strength could be obtained. In addition, in the cured product of the example containing a (meth)acrylic monomer component and a photopolymerization initiator, having an adhesive strength of the cured product of 1.5 N or less and an impact absorbency of the cured product of 20% or more and 80% or less, the cured product had high shape recoverability 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 were inferior in elongation at break. Further, cracks and fissures occurred in the cured products of Comparative Examples 1A to 3A in the shape recovery test.

[0209] In addition, in Examples 40A and 41A in which (a) the (meth)acrylic monomer (A) includes a (meth)acrylic monomer (A-1) having a molecular weight of 300 g / mol or more and 600 g / mol or less per (meth)acryloyl group and a (meth)acrylic monomer (A-2) having a molecular weight of more than 600 g / mol and 15,000 g / mol or less per (meth)acryloyl group, it was found that after stress release, they recovered to the original shape in 0 seconds or more and less than 1 second and had excellent shape recoverability. (b) In Examples 7A, 12A, 14A, 15A, and 18A containing a (meth)acrylic monomer (B-1) having two aromatic rings and a (meth)acrylic monomer (B-2) having one aromatic ring, it was found that after stress release, they recovered to the original shape in 0 seconds or more and less than 1 second and had excellent shape recoverability. It was found that Examples 38A and 39A satisfying both conditions (a) and (b) recovered to the original shape in 0 seconds or more and less than 1 second after stress release and had excellent shape recoverability.

[0210] <<Example B>> Example B is an example for more specifically explaining the second embodiment in the present disclosure. <Preparation of photocurable composition> [Examples 1B to 35B, Comparative Example 2B] Each component shown in Tables 4 to 7 below was mixed to obtain a photocurable composition. The viscosities of the respective photocurable compositions are shown in Tables 4 to 7. Note that the above viscosity was measured by the same method as the above-described method.

[0211] [Comparative Example 1B] As the photocurable composition, Gingiva Mask (manufactured by NextDent) was used.

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

[0213] (Elongation at break) The obtained photocurable composition was shaped into the shape of a dumbbell-shaped test piece conforming to ISO 37-2 using a 3D printer (Kulzer, Cara Print 4.0) under the conditions of a visible light wavelength of 405 nm and a visible light illuminance of 8.0 mJ / cm 2 to obtain a shaped article (lamination width 50 μm). The obtained shaped article was irradiated with ultraviolet light having a wavelength of 365 nm under the condition of 10 J / cm 2 to be fully cured, thereby obtaining a photocured article (i.e., a cured article). The elongation at break of the obtained photocured article (hereinafter referred to as "test piece") was measured in accordance with ISO 37:2017. These measurements were performed using a tensile test apparatus (manufactured by Shimadzu Corporation) under the condition of a tensile speed of 500 ± 50 mm / min.

[0214] (Shore A hardness) The obtained photocurable composition was shaped into the shape of a dumbbell-shaped test piece conforming to ISO 37-2 using a 3D printer (Kulzer, Cara Print 4.0) under the conditions of a visible light wavelength of 405 nm and a visible light illuminance of 8.0 mJ / cm 2Under the conditions, a shaped object (lamination width: 50 μm) with a length of 25 mm, a width of 25 mm, and a thickness of 6 mm was formed. The obtained For the obtained shaped object, ultraviolet light with a wavelength of 365 nm was irradiated under the condition of 10 J / cm 2 to fully cure the shaped object, thereby obtaining a photo-cured object (i.e., a cured object). The obtained photo-cured object (hereinafter referred to as "test piece") was measured for Shore A hardness in accordance with ISO 7619-1:2010. For the hardness measurement, a durometer-type hardness tester (manufactured by Mitutoyo Corporation) was used, and the value 15 seconds after the needle penetration was taken as the value of Shore A hardness.

[0215] (Adhesion) The obtained photocurable composition was formed into a shaped object (lamination width: 50 μm) with a length of 20 mm, a width of 20 mm, and a thickness of 2 mm using a 3D printer (Kulzer, Cara Print4.0) under the conditions of a visible light wavelength of 405 nm and a visible light illuminance of 8.0 mJ / cm 2 For the obtained shaped object, ultraviolet light with a wavelength of 365 nm was irradiated under the condition of 10 J / cm 2 to fully cure the shaped object, thereby obtaining a photo-cured object. The obtained photo-cured object (hereinafter referred to as "test piece") was attached to the sample stage so as not to sag. Next, an aluminum probe with a contact area of 10 mm in length and 10 mm in width was brought into contact with the 20 mm × 20 mm surface of the test piece, and held for 1.0 ± 0.1 seconds under a contact load of 0.98 ± 0.01 N / cm 2 . Thereafter, using a tensile test apparatus (manufactured by Shimadzu Corporation), the above probe was peeled off vertically from the contact surface at a speed of 5 ± 0.5 mm per second. Then, the maximum load required to peel off the above probe from the contact surface was determined and taken as the adhesion (unit: N) of the cured object.

[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 each 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 × 10 B is meant. 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 structure of each of the (meth)acrylic monomers (A) having two (meth)acryloyloxy groups and two urethane bonds described in Tables 4 to 7 is as follows.

[0222]

Chemical formula

[0223] UA-160TM, manufactured by Shin-Nakamura Chemical Co., Ltd., urethane diacrylate monomer having a polyether backbone UA-122P, manufactured by Shin-Nakamura Chemical Co., Ltd., urethane diacrylate monomer having a polyether backbone UN-6305, manufactured by Negami Kogyo Co., Ltd., urethane diacrylate monomer having a polyether backbone UN-2700, manufactured by Negami Kogyo Co., Ltd., urethane diacrylate monomer Urethane diacrylate monomer manufactured by Koge Kogyo Co., Ltd., UN-2600 Urethane diacrylate monomer manufactured by Koge Kogyo Co., Ltd., UN-352 Urethane diacrylate monomer manufactured by Kyoeisha Chemical Co., Ltd., AH-600 Compound manufactured by the method described in Production Example 1B below, urethane diacrylate monomer, MMD-352 Urethane diacrylate monomers, Ebecryl8402 and Ebecryl230, manufactured by Daicel Ornex Co., Ltd. Urethane diacrylate monomer, Ebecryl4859, manufactured by Daicel Ornex Co., Ltd. Ethoxylated bisphenol A diacrylate manufactured by Shin-Nakamura Chemical Co., Ltd., ABE-300

[0224] [Production Example 1B: Production of MMD-352] In a 1-liter four-necked flask equipped with a well-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 after stirring until homogeneous, the temperature was raised to 60°C. Subsequently, 188 g (1.00 mol) of XDI (m-xylylene diisocyanate) was added dropwise over 1 hour. Since the internal temperature rose due to the heat of reaction during the dropwise addition, the dropwise addition rate was controlled so that the temperature would be 80°C or lower. After the total amount had been added dropwise, the reaction temperature was maintained at 80°C and the reaction was carried out for 10 hours. At this time, the progress of the reaction was monitored by HPLC analysis to confirm the end point of the reaction. By discharging the product from the reactor, 600 g of urethane diacrylate monomer (MMD-352) was obtained. The viscosity at 65°C was 6210 mPa·s.

[0225] [(Meth)acrylic monomer (B) having one acryloyl group] The structures of each of the (meth)acrylic monomers (B) having one acryloyl group described in Tables 4 to 7 are as follows.

[0226] [Chemical]

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

[0228] [Photoinitiator] The structures of each of the photoinitiators described in Tables 4 to 7 are as follows.

[0229] [Chemical]

[0230] Omnirad TPO is manufactured by IGM resins B.V. Omnirad 819 is manufactured by IGM resins B.V.

[0231] As shown in Tables 4 to 7, in the examples, a cured product excellent in elongation at break and with suppressed adhesive force could be obtained. On the other hand, the cured product obtained in Comparative Example 1B did not have its adhesive force suppressed.

[0232] [Manufacture of mouse guard] [Example 1C] The plaster models of the upper and lower jaws and the occlusal state were each converted into three-dimensional impression data using a dental scanner for the laboratory (Kulzer, Cara Scan 4.0). The respective three-dimensional impression data were uploaded to CAD design (DENTCA, DENTCAdesign.com). The outer shape of the mouse guard was designed on the software, and the thickness of the occlusal surface of the central incisor part was set to 2.5 mm, and the thickness of the occlusal surface of the second molar part was set to 1.0 mm (i.e., the thickness of the occlusal surface of the central incisor part was 2.5 times the thickness of the occlusal surface of the second molar part). By automatic calculation using the algorithm of the software, the three-dimensional modeling data of the target upper jaw mouse guard were obtained. Using a 3D printer (Kulzer, Cara Print 4.0), under the conditions of a wavelength of visible light of 405 nm and an illuminance of visible light of 8.0 mJ / cm2, the photocurable composition of Example 1A was shaped using the three-dimensional modeling data of the mouse guard obtained above to obtain an upper jaw mouse guard shaped article. The obtained mouse guard shaped article was irradiated with ultraviolet light having a wavelength of 365 nm under the condition of 10 J / cm2 to fully cure the shaped article, thereby obtaining a mouse guard. When the obtained mouse guard was fitted into the plaster models of the upper and lower jaws, it fit with very good compatibility.

[0233] <Comparative Example 1C> The same operations as in Example 1C were performed except that the thickness of the occlusal surface of the central incisor part was set to 2.0 mm and the thickness of the occlusal surface of the second molar part was set to 2.0 mm (i.e., the thickness of the occlusal surface of the central incisor part was 1 times the thickness of the occlusal surface of the second molar part). By automatic calculation using the algorithm of the software, the three-dimensional modeling data of the target mouse guard were obtained. Using a 3D printer (Kulzer, Cara Print 4.0), under the conditions of a wavelength of visible light of 405 nm and an illuminance of visible light of 8.0 mJ / cm2, the photocurable composition of Example 1B was shaped using the three-dimensional modeling data of the mouse guard obtained above to obtain a mouse guard shaped article. The obtained mouse guard-shaped object was irradiated with ultraviolet light having a wavelength of 365 nm under the condition of 10 J / cm2 to fully cure the shaped object, thereby obtaining a mouse guard.

[0234] <Bite appliance wearing test> Regarding the mouse guards produced by the methods of Example 1C and Comparative Example 1C, the upper jaw mouse guard was attached to a bite appliance on which plaster models of the upper and lower jaws were mounted, and evaluation was performed according to the following criteria. ~Evaluation criteria~ A: When attached to the bite appliance, without bite adjustment, the upper jaw mouse guard could be brought into contact with the central incisor part of the lower jaw of the plaster model and the second molar part of the lower jaw of the plaster model, respectively. B: When attached to the bite appliance, the upper jaw mouse guard was in contact with the second molar part of the lower jaw of the plaster model, but a gap occurred between the upper jaw mouse guard and the central incisor part of the lower jaw of the plaster model, and bite adjustment was required 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 hereby incorporated by reference in their entirety into this specification. All documents, patent applications, and technical standards described in this specification are incorporated by reference into this specification to the same extent as if each individual document, patent application, and technical standard was specifically and individually stated to be incorporated by reference.

Claims

1. A photocurable composition comprising a (meth)acrylic monomer component and a photoinitiator, wherein 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.

2. The photocurable composition according to claim 1, wherein the elongation at break of the cured product is 40% or more.

3. A photocurable composition comprising a (meth)acrylic monomer component and a photoinitiator, wherein the adhesive strength of the cured product is 1.5 N or less, and the impact absorbency of the cured product is 20% or more and 80% or less.

4. The photocurable composition according to claim 3, wherein the impact absorbency of the cured product is 20% or more and 70% or less.

5. The photocurable composition according to claim 3 or claim 4, wherein the elongation at break of the cured product is 20% or more.

6. A photocurable composition comprising a (meth)acrylic monomer component and a photoinitiator, wherein 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.

7. The photocurable composition according to any one of claims 1 to 6, wherein the aromatic ring concentration in the (meth)acrylic monomer component is 0.00100 mol / g or more.

8. 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, and the photocurable composition according to any one of claims 1 to 7.

9. The photocurable composition according to claim 8, wherein at least one of the (meth)acrylic monomer (A) and the (meth)acrylic monomer (B) has an aromatic group.

10. A photocurable composition comprising a (meth)acrylic monomer component and a photoinitiator, 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, and 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 photocurable composition according to any one of claims 8 to 10, wherein the content of the (meth)acrylic monomer (A) is 250 parts by mass to 800 parts by mass with respect to 1000 parts by mass of the total content of the (meth)acrylic monomer (A) and the (meth)acrylic monomer (B).

12. The photocurable composition according to any one of claims 8 to 11, wherein the (meth)acrylic monomer (A) contains a compound represented by the following formula (1). 【Chemical 1】 (In formula (1), R １ and R ２ each independently represents a divalent linking group, and R ３ each independently represents a methyl group or a hydrogen atom.)

13. Said R １ is a group consisting of a divalent chain hydrocarbon group or 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 claim 12, wherein the divalent hydrocarbon group having the aromatic structure is a divalent hydrocarbon group represented by the following formula (1-a). 【Chemical 2】 (In formula (1-a), * represents the bonding position.)

14. Said R １ The photocurable composition according to claim 12, wherein R is a group composed of at least one group selected from the group consisting of a divalent chain hydrocarbon group, a divalent chain hydrocarbon group, a divalent hydrocarbon group having an alicyclic structure, and a divalent group containing a hetero atom.

15. Said R １ The photocurable composition according to claim 13 or claim 14, wherein the divalent group containing the hetero atom in said R contains at least one bond selected from the group consisting of a urethane bond and an ether bond.

16. The photocurable composition according to any one of claims 8 to 15, satisfying at least one of the following (a) and the following (b). (a) The (meth)acrylic monomer (A) includes a (meth)acrylic monomer (A-1) having a molecular weight of 300 g / mol or more and 600 g / mol or less per (meth)acryloyl group, and a (meth)acrylic monomer (A-2) having a molecular weight of more than 600 g / mol and 15000 g / mol or less per (meth)acryloyl group. (b) The (meth)acrylic monomer (B) includes a (meth)acrylic monomer (B-1) having two aromatic rings and a (meth)acrylic monomer (B-2) having one aromatic ring.

17. The photocurable composition according to any one of claims 8 to 16, wherein the aromatic ring concentration in the (meth)acrylic monomer (A) is 0.0016 mol / g or less.

18. The photocurable composition according to any one of claims 8 to 17, wherein the total content of the (meth)acrylic monomer (A) and the (meth)acrylic monomer (B) in the (meth)acrylic monomer component is 90% by mass or more.

19. Z1 in the following formula β is 1 × 10 ４ to 100 × 10 ４ The photocurable composition according to any one of claims 7 to 18. Z1 = X1 / Y1 Formula β X1 (g / mol): The molecular weight of the (meth)acrylic monomer (A) per (meth)acryloyl group Y1 (mol / g): The aromatic ring concentration in the (meth)acrylic monomer component

20. The photocurable composition according to any one of claims 1 to 19, wherein the viscosity measured at 25°C and 50 rpm in an E-type viscometer is 10 mPa·s to 5000 mPa·s.

21. The photocurable composition according to any one of claims 1 to 20, which is for optical forming.

22. The photocurable composition according to any one of claims 1 to 21, which is used for producing dental products by optical forming.

23. The photocurable composition according to any one of claims 1 to 22, which is used for producing a mouthpiece, a gingiva mask or a backing material by optical forming.

24. A dental product comprising a cured product of the photocurable composition according to any one of claims 1 to 23.

25. The dental product according to claim 24, which is for a mouthpiece, a gingiva mask or a backing material.

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