Resin composition for light molding

Abstract

The invention relates to a resin composition for light modeling. The present invention provides a resin composition for light shaping, which is easy to shape by light shaping and has excellent deformation recovery, toughness and water resistance of a cured product. The present invention relates to a resin composition for light shaping, which contains (A) a polymerizable compound having a homopolymer glass transition temperature (Tg) of 37 DEG C or more and (B) a photopolymerization initiator, and which has a tan [delta] at 37 DEG C after curing of 0.3 or less.

Description

This application is a divisional application of the PCT application entering the national phase with application number 202080069270.1 (international filing date is April 1, 2022) and invention name "Resin composition for photomolding" Technical Field

[0001] The present invention relates to a resin composition for photomolding. More specifically, the present invention enables the production of three-dimensional objects that are easily molded using photomolding and exhibit excellent deformation recovery, toughness, and water resistance. The composition is particularly suitable for use as a base material for dental crowns and dentures. Background Art

[0002] Patent Document 1 discloses a method for producing a three-dimensional object by supplying a controlled amount of light energy to a liquid photocurable resin to cure it into a thin layer, then supplying further liquid photocurable resin thereon and then irradiating it with light under controlled conditions to cure the layers in a stacked, thin layer. This process, known as the optical three-dimensional molding method, is described. Furthermore, a basic practical method is further proposed in Patent Document 2, and since then, numerous proposals have been made for optical three-dimensional molding technology.

[0003] As a representative method for optically manufacturing three-dimensional objects, the liquid tank optical molding method is commonly used. In this method, the liquid surface of a liquid photocurable resin composition contained in a container is selectively irradiated with a computer-controlled ultraviolet laser in a desired pattern, causing it to cure to a predetermined thickness to form a solid layer. Subsequently, a layer of liquid photocurable resin composition is supplied on top of this solid layer and irradiated with ultraviolet laser light. This is cured in the same manner as described above to form a continuous solid layer. This layering operation is repeated to produce the final shape of the three-dimensional object. When using this method, even if the shape of the object is very complex, it can be easily and quickly manufactured with high precision. Therefore, it has attracted much attention in recent years.

[0004] Furthermore, the applications of three-dimensional objects created using optical modeling have expanded from simple conceptual models to test models and prototypes, leading to an increasing demand for superior molding precision. Furthermore, these properties are also being demanded to be superior in properties that are tailored to the intended purpose. In particular, in the field of dental materials, the shapes of dental crowns and denture bases vary greatly from patient to patient and are complex, leading to the anticipated application of optical modeling.

[0005] Dental braces are devices such as orthodontic braces worn on the teeth to correct tooth alignment, also known as dental splints, worn to correct jaw position, worn at night to treat sleep apnea, worn to reduce tooth wear caused by bruxism, and worn inside the mouth to protect the jaw and brain from the intense forces exerted on the teeth and jawbone during contact sports. Their use in dental braces has rapidly expanded in recent years due to their aesthetic appeal and ease of removal. Sleep apnea is also a medical condition receiving significant attention, and their use as a treatment for the condition is rapidly expanding.

[0006] Denture base material is the material used to support the gums when wearing dentures due to tooth loss. In recent years, the demand for dentures has been rapidly increasing with the increase in the aging population.

[0007] These dental braces and denture base materials are required to have deformation recovery, toughness and water resistance. This is especially true for orthodontic appliances and partial denture bases that do not contain metal clasps, commonly known as claspless dentures. If the deformation recovery is impaired, the corrective force or impact absorption is lost, and the device cannot function as a wearable device. If the toughness is impaired, there are the following problems: the wearing feel deteriorates or it is easy to break, requiring frequent remaking. Furthermore, if the water resistance is impaired, there are the following problems: the mechanical properties are reduced, and the corrective force or impact absorption is inevitably lost, or it is easy to break and is not practical.

[0008] Furthermore, when producing dental braces, denture base materials, and sleep apnea treatment devices, oral impressions must be taken. However, taking impressions has long been cited as a problem: it is a burden on patients due to its discomfort and requires skilled labor. In recent years, with the advancement of digital technology, attempts have been made to apply optical intraoral scanning to impression taking, and to apply optical 3D modeling to molding. Photocurable resin compositions are used for molding, but there is a general tendency for resin compositions that exhibit greater flexibility and water resistance to use monomers with lower polarity. This results in lower curability, which in turn contributes to the tendency for the cured product to have poor deformation recovery. In optical 3D modeling, light exposure time is particularly short, and each layer of molding is exposed to oxygen. This makes curing particularly prone to inadequate, making it difficult to achieve both deformation recovery, toughness, and water resistance. Furthermore, the resin composition needs to have a viscosity that allows molding. However, using low-molecular-weight monomers to reduce viscosity tends to reduce curability. On the other hand, monomers that exhibit deformation recovery are often high-molecular-weight, high-viscosity monomers, which can reduce molding properties. Therefore, it is difficult to impart excellent properties such as deformation recovery, toughness, and water resistance to the cured product of the three-dimensional modeling resin composition as a whole, and it is also difficult to obtain a product having low viscosity and excellent modeling properties.

[0009] Against this backdrop, a technology for achieving excellent toughness and water resistance of cured products and enabling optical three-dimensional modeling has been proposed. For example, Patent Document 3 proposes a photocurable resin composition comprising (meth)acrylamide-based urethane oligomers and (meth)acrylic compounds having high Tg homopolymers as essential components. However, no description is made regarding deformation recovery properties.

[0010] Prior art literature Patent Literature Patent Document 1: Japanese Patent Application Laid-Open No. 56-144478 Patent Document 2: Japanese Patent Application Laid-Open No. 60-247515 Patent Document 3: International Publication No. 2017 / 047615. Summary of the Invention

[0011] Problems to be solved by the invention Therefore, the present invention aims to provide a photomolding resin composition that is easy to shape using photomolding and whose cured product exhibits excellent deformation recovery, toughness, and water resistance. A further object is to provide a photomolding resin composition suitable for use as a base material for dental crowns and dentures, particularly orthodontic appliances and clasp-free dentures.

[0012] Means for solving problems That is, the present invention includes the following technical solutions.

[0013] [1] A resin composition for photomodeling, comprising a polymerizable compound (A) having a homopolymer glass transition temperature (Tg) of 37°C or higher and a photopolymerization initiator (B), wherein the resin composition for photomodeling has a tan δ of 0.3 or less at 37°C after curing; [2] The resin composition for photomodeling according to [1], wherein the peak temperature of tan δ after curing is 60°C or higher; [3] The resin composition for photomodeling according to [1] or [2], further comprising a polymerizable compound (C) having a homopolymer glass transition temperature (Tg) of less than 37°C; [4] The resin composition for photomodeling according to any one of [1] to [3], wherein the tan δ at 200°C after curing is 0.5 or less; [5] The resin composition for photomodeling according to any one of [1] to [4], wherein the polymerizable compound (A) contains a monofunctional polymerizable monomer (A1); [6] The resin composition for photomolding according to [5], wherein the monofunctional polymerizable monomer (A1) contains a monofunctional (meth)acrylate compound and / or a monofunctional (meth)acrylamide compound; [7] The resin composition for photomolding according to [6], wherein the monofunctional polymerizable monomer (A1) contains a monofunctional (meth)acrylate compound, and the monofunctional (meth)acrylate compound contains at least one selected from the group consisting of an aromatic ring-containing (meth)acrylate compound, an alicyclic (meth)acrylate compound, and a nitrogen atom-containing cyclic (meth)acrylate compound; [8] The resin composition for photomodeling according to [7], wherein the monofunctional (meth)acrylate compound contains a nitrogen-containing cyclic (meth)acrylate compound; [9] The resin composition for photomodeling according to [8], wherein the nitrogen-containing cyclic (meth)acrylate compound comprises at least one selected from pentamethylpiperidinyl (meth)acrylate, tetramethylpiperidinyl (meth)acrylate, and 4-(pyrimidin-2-yl)piperazin-1-yl (meth)acrylate;

[10] The resin composition for photomodeling according to any one of [1] to [9], wherein the polymerizable compound (A) contains a polyfunctional polymerizable monomer (A2);

[11] The resin composition for photomodeling according to

[10] , wherein the polyfunctional polymerizable monomer (A2) contains an aliphatic polyfunctional polymerizable monomer;

[12] The resin composition for photomodeling according to

[10] , wherein the polyfunctional polymerizable monomer (A2) contains an alicyclic polyfunctional polymerizable monomer;

[13] The resin composition for photomodeling according to

[12] , wherein the alicyclic multifunctional polymerizable monomer contains tricyclodecane dimethanol di(meth)acrylate;

[14] The resin composition for photomodeling according to any one of

[10] to

[13] , wherein the polyfunctional polymerizable monomer (A2) contains a heterocyclic ring-containing polyfunctional polymerizable monomer;

[15] The resin composition for photomodeling according to any one of [3] to

[14] , wherein the polymerizable compound (C) contains a urethanized (meth)acrylic compound (C1);

[16] The resin composition for photomolding according to

[15] , wherein the urethanized (meth)acrylate compound (C1) is a (meth)acrylate containing at least one structure selected from polyester, polycarbonate, polyurethane, polyether, polyconjugated diene and hydrogenated polyconjugated diene, and a urethane bond in one molecule;

[17] The resin composition for photomodeling according to

[15] or

[16] , wherein the urethanized (meth)acrylic compound (C1) is a (meth)acrylate containing a polyol moiety and a urethane bond in one molecule, wherein the polyol moiety is at least one selected from polyesters, polycarbonates, polyurethanes, polyethers, polyconjugated dienes, and hydrogenated polyconjugated dienes having a structure derived from a branched aliphatic diol unit having 4 to 18 carbon atoms;

[18] A dental material comprising a cured product of the photomolding resin composition described in any one of [1] to

[17] ;

[19] A dental brace comprising a cured product of the photomolding resin composition described in any one of [1] to

[17] ;

[20] A denture base material comprising a cured product of the photomolding resin composition described in any one of [1] to

[17] ;

[21] A material for treating sleep disorders, comprising a cured product of the photomolding resin composition described in any one of [1] to

[17] ;

[22] A method for producing a three-dimensional object by an optical three-dimensional molding method using the resin composition for optical molding according to any one of [1] to

[17] .

[0014] Effects of the Invention The photomolding resin composition of the present invention is easy to mold, and the cured product has excellent deformation recovery, toughness, and water resistance. Therefore, it can be suitably used in various dental materials (particularly dental crowns and denture base materials, especially orthodontic appliances and clasp-free dentures) or various sleep disorder treatment materials (particularly treatment devices for sleep apnea syndrome). DETAILED DESCRIPTION

[0015] The photomodeling resin composition of the present invention comprises a polymerizable compound (A) having a homopolymer glass transition temperature (Tg) of 37°C or higher and a photopolymerization initiator (B), wherein the photomodeling resin composition has a tan δ of 0.3 or less at 37°C after curing.

[0016] From the perspective of deformation recovery, the cured product of the photomodeling resin composition of the present invention must have a tan δ (loss tangent) of 0.3 or less at 37°C, preferably 0.2 or less, and more preferably 0.1 or less. The tan δ of a cured product at 37°C represents the viscoelasticity of the cured product at 37°C and is expressed by the following formula. A low tan δ value of a cured product at 37°C indicates low viscosity and high elasticity, and tends to facilitate shape retention.

[0017] tanδ=E” / E' (Wherein, E" represents the loss modulus and E' represents the storage modulus.)

[0018] In order to reduce the tan δ at 37°C of a cured product of a photolithography resin composition, it is effective to shift the tan δ peak away from 37°C toward the higher or lower temperature side. However, if the tan δ peak of a homopolymer is away from 37°C, the tan δ at 37°C of a polymerizable compound does not necessarily have a low value. This is complicated by factors such as the copolymerizability of the polymerizable compound contained in the composition, the Tg and content ratio of the homopolymer, the density of the polymerizable groups in the composition, the crosslinking density, and compatibility with additives such as polymerization initiators and inhibitors. The method for measuring tan δ at 37°C in the present invention is described in detail in the Examples below.

[0019] Regarding the cured product of the resin composition for photomodeling of the present invention, from the perspective of deformation recovery and toughness, the peak temperature of tan δ is preferably 60°C or higher, more preferably 80°C or higher, and even more preferably 100°C or higher. The peak temperature of tan δ indicates the binding force of the physical crosslinking point (binding point). When the peak temperature of tan δ is high, the binding force of the physical crosslinking point is strong, and when subjected to stress, the network structure of the cured product is not easily destroyed, and the shape stability of the cured product is excellent. In order to make the peak temperature of tan δ of the cured product of the resin composition for photomodeling above 60°C, it is effective to contain a polymerizable compound with a high homopolymer Tg. However, if a polymerizable compound with a high homopolymer Tg is contained alone, the cured product may become brittle. Therefore, it is possible to also contain a polymerizable compound with a low homopolymer Tg. However, the peak temperature of tan δ is also complicated by the copolymerization of the polymerizable compound with a high homopolymer Tg and the polymerizable compound with a low homopolymer Tg, and the compatibility with additives such as polymerization initiators and inhibitors. In addition, the method for measuring the peak top temperature of tan δ in the present invention is described in detail in the examples described later.

[0020] Regarding the cured product of the resin composition for light shaping of the present invention, from the viewpoint of deformation recovery and strength, the tanδ at 200°C is preferably 0.5 or less, more preferably 0.4 or less, and further preferably 0.3 or less. The tanδ at 200°C of the cured product has a tendency to represent crosslinking points (crosslinking density) based on covalent (chemical) bonds. When the cured product has crosslinking points based on covalent (chemical) bonds, a tendency for the storage modulus to increase and tanδ to decrease in the high temperature region can be observed. Therefore, the tanδ at 200°C of the cured product being 0.5 or less means that: within the range where the cured product does not become brittle, there are not only crosslinking points based on physical crosslinking but also crosslinking points based on chemical bonds, which means that the shape stability is better. It should be noted that in order to make the tan δ of the cured product of the photomolding resin composition at 200°C below 0.5, it is effective to contain a difunctional or higher-functional polymerizable compound. However, if a difunctional or higher-functional polymerizable compound is contained alone, the cured product may become brittle. Therefore, it is possible to consider containing a polymerizable compound with a low homopolymer Tg or controlling the molecular weight and number of functional groups of the difunctional or higher-functional polymerizable compound. However, the copolymerizability and crosslinking density of the polymerizable compound contained in the composition also have a complex influence on the tan δ at 200°C. It should be noted that the method for measuring the tan δ at 200°C in the present invention is described in detail in the Examples described below.

[0021] In summary, in the present invention, in the case of a resin composition for photomodeling that satisfies all the conditions of tanδ of 0.3 or less at 37°C, tanδ peak temperature of 60°C or more, and tanδ of 0.5 or less at 200°C after curing, it is particularly excellent in deformation recovery and has both styling properties, toughness, and water resistance, and is therefore optimal. As mentioned above, in order to have such suitable viscoelasticity, it is important to select the conditions taking into account the type, content, composition, and other components of the polymerizable compound contained in the composition. The following is a detailed description of the resin composition for photomodeling of the present invention. It should be noted that in this specification, the upper limit and lower limit of the numerical range (the content of each component, the value calculated from each component, and each physical property, etc.) can be appropriately combined.

[0022] [Polymerizable compound (A) having a homopolymer Tg of 37°C or higher] The resin composition for photomolding of the present invention contains a polymerizable compound (A) (hereinafter sometimes referred to as "polymerizable compound (A)") having a homopolymer Tg of 37°C or above, thereby increasing the Tg of the three-dimensional molded object after light irradiation, further improving the cohesive force, and being able to form a three-dimensional molded object with good deformation recovery and strength.

[0023] What is important about the polymerizable compound (A) in the present invention is that the Tg of its homopolymer is 37°C or higher. By making the Tg of the homopolymer 37°C or higher, a rigid structure is introduced, thereby being able to form a three-dimensional shaped object with good deformation recovery and strength. The Tg of the aforementioned homopolymer is preferably 60°C or higher, more preferably 80°C or higher, and further preferably 100°C or higher. The upper limit of the Tg of the aforementioned homopolymer is not particularly limited, but is preferably 400°C or lower, more preferably 300°C or lower, and further preferably 250°C or lower. The polymerizable compound (A) may be used alone or in combination of two or more. It should be noted that in the present invention, the Tg of the compound can be measured using a viscoelasticity measuring device (rheometer), a differential scanning calorimeter (DSC), etc., using a conventionally known method. For example, regarding the glass transition temperature (Tg), a rotational rheometer (manufactured by Thei Instruments Japan Co., Ltd., "AR2000") is used to measure the dynamic viscoelasticity of a compound (e.g., a homopolymer of the polymerizable compound (A)). In this dynamic viscoelasticity measurement, the frequency is set to 10 Hz, the load is set to 10 N, the displacement is set to 0.1%, and the torque is set to 20 μNm. The temperature at which tan δ shows a peak can be determined as the glass transition temperature Tg.

[0024] In this specification, polymerizable compound means a compound containing polymerizable groups such as (meth) acryloyl, vinyl, styryl, etc., as long as it contains a polymerizable group, it can be a monomer, it can be a dimer, or it can be a polymer. The polymerizable compound (A) in the present invention can use a monofunctional polymerizable monomer (A1) having one polymerizable group and / or a multifunctional polymerizable monomer (A2) having two or more polymerizable groups. Among them, from the viewpoint of excellent toughness of the obtained cured product, it is preferred to contain a monofunctional polymerizable monomer (A1), more preferably a monofunctional (meth) acrylate compound and / or a monofunctional (meth) acrylamide. It should be noted that in this specification, the expression "(meth) acryloyl" is used to include both methacryloyl and acryloyl, and the same is true for expressions such as "(meth) acryloyl" and "(meth) acrylate" similar to them.

[0025] Examples of the monofunctional polymerizable monomer (A1) include monofunctional (meth)acrylate compounds such as aromatic ring-containing (meth)acrylate compounds, alicyclic (meth)acrylate compounds, and nitrogen-containing cyclic (meth)acrylate compounds; and monofunctional (meth)acrylamide compounds such as cyclic (meth)acrylamide compounds. The monofunctional polymerizable monomer (A1) may be used alone or in combination of two or more.

[0026] Examples of the aromatic ring-containing (meth)acrylate compound include monofunctional (meth)acrylate compounds having two or more aromatic rings, such as o-phenylphenol (meth)acrylate, m-phenylphenol (meth)acrylate, p-phenylphenol (meth)acrylate, phenyl (meth)acrylate, 4-biphenyl (meth)acrylate, 1-naphthyl (meth)acrylate, 2-naphthyl (meth)acrylate, anthracene (meth)acrylate, o-2-propenylphenyl (meth)acrylate, benzhydrol (meth)acrylate, cumylphenol (meth)acrylate, fluorenyl (meth)acrylate, and fluorenylmethyl (meth)acrylate.

[0027] Examples of the alicyclic (meth)acrylate compound include 2-(1-adamantyl)propyl (meth)acrylate, 2-methyladamantane-2-yl (meth)acrylate, 2-ethyladamantane-2-yl (meth)acrylate, 2-n-propyladamantane-2-yl (meth)acrylate, 2-isopropyladamantane-2-yl (meth)acrylate, 1-(adamantane-1-yl)-1-methylethyl (meth)acrylate, 1-(adamantane-1-yl)-1-ethylethyl (meth)acrylate, 1-(adamantane-1-yl)-1-methylpropyl (meth)acrylate, and 1-(adamantane-1-yl)-1-ethylpropyl (meth)acrylate.

[0028] Examples of nitrogen-containing cyclic (meth)acrylate compounds include monofunctional (meth)acrylate compounds containing a heterocyclic ring containing only nitrogen atoms as heteroatoms, such as pentamethylpiperidinyl (meth)acrylate, tetramethylpiperidinyl (meth)acrylate, and 4-(pyrimidin-2-yl)piperazin-1-yl (meth)acrylate. These compounds may be used alone or in combination of two or more.

[0029] Examples of the cyclic (meth)acrylamide compound include N-(meth)acryloylmorpholine, N-(meth)acryloylpyrrolidine, N-(meth)acryloylpiperidine, N-(meth)acryloyl-2-methylpiperidine, and N-(meth)acryloyl-2,2,6,6-tetramethylpiperidine.

[0030] Among these, the monofunctional polymerizable monomer (A1) is preferably N-(meth)acryloylmorpholine, fluorenyl(meth)acrylate, fluorenylmethyl(meth)acrylate, phenyl(meth)acrylate, 4-biphenyl(meth)acrylate, 1-naphthyl(meth)acrylate, 2-naphthyl(meth)acrylate, anthracene(meth)acrylate, diphenylmethanol(meth)acrylate, cumylphenol(meth)acrylate, N-acryloylmorpholine, piperidinylacrylamide, tetramethylpiperidinylacrylamide, pentamethyl ...1-naphthyl(meth)acrylate, 1-naphthyl(meth)acrylate, 1-naphthyl Piperidinyl ester, tetramethylpiperidinyl (meth)acrylate, more preferably fluorenyl (meth)acrylate, fluorenylmethyl (meth)acrylate, 4-biphenyl (meth)acrylate, 1-naphthyl (meth)acrylate, 2-naphthyl (meth)acrylate, diphenylmethanol (meth)acrylate, cumylphenol (meth)acrylate, piperidinyl acrylamide, tetramethylpiperidinyl acrylamide, pentamethylpiperidinyl (meth)acrylate, tetramethylpiperidinyl (meth)acrylate, further preferably fluorenyl (meth)acrylate, fluorenylmethyl (meth)acrylate, 4-biphenyl (meth)acrylate, piperidinyl acrylamide, tetramethylpiperidinyl acrylamide.

[0031] Examples of the polyfunctional polymerizable monomer (A2) include aliphatic polyfunctional polymerizable monomers without a cyclic structure and polyfunctional polymerizable monomers with a cyclic structure. The cyclic structure is not particularly limited as long as the effects of the present invention are exhibited, and examples thereof include aromatic monocyclic rings such as a benzene ring, a biphenyl ring, and a triphenylmethyl ring; aromatic condensed bicyclic rings such as a naphthalene ring, a pentylene ring, an indene ring, an indane ring, a tetrahydronaphthalene ring, and an azulene ring; carbon condensed tricyclic rings such as an as-indacene ring, an s-indacene ring, an acenaphthylene ring, an acenaphthylene ring, a fluorene ring, a phenanthene ring, a perinaphtene ring, a phenanthrene ring, and an anthracene ring; examples thereof include a norbornane ring, a tetracyclododecane ring, an adamantane ring, a dicyclopentene ring, a tricyclodecadecane ring, and a tricyclodecane ring. Saturated hydrocarbon rings such as dioxane, cyclopentane, cyclohexane, cycloheptane, cyclooctane, and cyclodecane; unsaturated hydrocarbon rings such as norbornene, tetralin, and fluorene; saturated monocyclic rings with one nitrogen atom such as pyrrolidine and piperidine; saturated monocyclic rings with two or more nitrogen atoms such as piperazine, hexamethylenetetramine, and isocyanurate; unsaturated monocyclic rings with one nitrogen atom such as pyrrole and pyridine; unsaturated monocyclic rings with two or more nitrogen atoms such as imidazole, indazole, imidazoline, pyrazole, pyrazine, pyrimidine, triazole, triazine, and tetrazole; indole , unsaturated polycyclic rings with one nitrogen atom such as isoindole ring, quinoline ring, isoquinoline ring, carbazole ring; heterocyclic rings having only nitrogen atoms represented by unsaturated polycyclic rings with two or more nitrogen atoms such as benzimidazole ring, purine ring, benzotriazole ring, choline ring; heterocyclic rings having both nitrogen and oxygen atoms such as morpholine ring, lactam ring, oxazole ring, benzoxazine ring, hydantoin ring, phthalocyanine ring; heterocyclic rings having both nitrogen and sulfur atoms such as thiazole ring, thiazine ring, phenothiazine ring, etc. Among these, the curability and deformation recovery of the cured product of the obtained light shaping resin composition From the viewpoints of strength, toughness and water resistance, preferred are an aromatic single ring, an aromatic condensed bicyclic ring, a carbon condensed tricyclic ring, a saturated hydrocarbon ring, a saturated monocyclic ring having one nitrogen atom, a saturated monocyclic ring having two or more nitrogen atoms, and a heterocyclic ring having both a nitrogen atom and an oxygen atom; more preferred are an aromatic single ring, an aromatic condensed bicyclic ring, a saturated hydrocarbon ring, an unsaturated hydrocarbon ring, and a saturated monocyclic ring having one nitrogen atom; further preferred are an aromatic single ring, a saturated hydrocarbon ring, an unsaturated hydrocarbon ring, a saturated monocyclic ring having one nitrogen atom, and a saturated monocyclic ring having two or more nitrogen atoms.

[0032] As the multifunctional polymerizable monomer (A2), from the viewpoint of excellent deformation recovery, water resistance and strength of the cured product, there can be mentioned difunctional (meth)acrylate compounds such as 1,2-butanediol di(meth)acrylate, 1,3-propylene glycol di(meth)acrylate, 1,4-butanediol di(meth)acrylate, neopentyl glycol di(meth)acrylate, triethylene glycol di(meth)acrylate, dipropylene glycol di(meth)acrylate, tripropylene glycol di(meth)acrylate, and dodecane di(meth)acrylate; trimethylolpropane tri(meth)acrylate, pentaerythritol tri(meth)acrylate, pentaerythritol tetra(meth)acrylate; The present invention also includes aliphatic multifunctional polymerizable monomers such as trifunctional or higher-functional (meth)acrylate compounds such as bisphenol A di(meth)acrylate; aromatic ring-containing multifunctional polymerizable monomers such as ethoxylated bisphenol A di(meth)acrylate (ethylene oxide (EO) addition number: 3 mol%); alicyclic multifunctional polymerizable monomers such as 1,4-cyclohexanedimethanol di(meth)acrylate, dicyclopentanyl di(meth)acrylate, isobornyl di(meth)acrylate, hydrogenated bisphenol A di(meth)acrylate, and tricyclodecane dimethanol di(meth)acrylate; and heterocyclic multifunctional polymerizable monomers such as tris(2-hydroxyethyl)isocyanurate tri(meth)acrylate. The multifunctional polymerizable monomer (A2) may be used alone or in combination of two or more.

[0033] Suitable embodiments of the present invention include, for example, a photomolding resin composition in which the polymerizable compound (A) comprises a monofunctional polymerizable monomer (A1) and a polyfunctional polymerizable monomer (A2). Including the polyfunctional polymerizable monomer (A2) in the photomolding resin composition may facilitate lowering the tan δ value at 200°C when combined with other components.

[0034] The content of the polymerizable compound (A) in the photomodeling resin composition of the present invention is preferably 30 to 95% by mass of the total amount of the polymerizable compound (A), the polymerizable compound (C) described below, and other polymerizable compounds (hereinafter, the aforementioned three types are collectively referred to as "polymerizable compounds"). From the perspective of achieving better styling properties, deformation recovery properties, and strength of the cured product, the content of the polymerizable compound (A) is more preferably 35% by mass or more, and even more preferably 50% by mass or more of the total amount. Furthermore, from the perspective of achieving better styling properties, deformation recovery properties, and strength of the cured product, the content of the polymerizable compound (A) is more preferably 90% by mass or less, and even more preferably 80% by mass or less of the total amount.

[0035] [Photopolymerization initiator (B)] The photopolymerization initiator (B) used in the present invention can be selected from photopolymerization initiators generally used in the industrial field, and among them, photopolymerization initiators used for dental applications are preferred.

[0036] Examples of the photopolymerization initiator (B) include (bis)acylphosphine oxides, thioxanthones or quaternary ammonium salts of thioxanthones, ketals, α-diketones, coumarins, anthraquinones, benzoin alkyl ether compounds, α-aminoketone compounds, and germanium compounds. The photopolymerization initiator (B) may be used alone or in combination of two or more.

[0037] Among these photopolymerization initiators (B), at least one selected from (bis)acylphosphine oxides and α-diketones is preferably used. This allows for the production of a photopolymerization resin composition that exhibits excellent photocurability in both the ultraviolet and visible light regions and exhibits sufficient photocurability even when using any light source, including lasers, halogen lamps, light-emitting diodes (LEDs), and xenon lamps.

[0038] Among the (bis)acylphosphine oxides, examples of the acylphosphine oxides include 2,4,6-trimethylbenzoyldiphenylphosphine oxide, 2,6-dimethoxybenzoyldiphenylphosphine oxide, 2,6-dichlorobenzoyldiphenylphosphine oxide, 2,4,6-trimethylbenzoylmethoxyphenylphosphine oxide, 2,4,6-trimethylbenzoylethoxyphenylphosphine oxide, 2,3,5,6-tetramethylbenzoyldiphenylphosphine oxide, benzoylbis(2,6-dimethylphenyl)phosphonate, 2,4,6-trimethylbenzoylphenylphosphine oxide sodium salt, 2,4,6-trimethylbenzoylphenylphosphine oxide potassium salt, and ammonium salt of 2,4,6-trimethylbenzoyldiphenylphosphine oxide. Examples of the bisacylphosphine oxides include bis(2,6-dichlorobenzoyl)phenylphosphine oxide, bis(2,6-dichlorobenzoyl)-2,5-dimethylphenylphosphine oxide, bis(2,6-dichlorobenzoyl)-4-propylphenylphosphine oxide, bis(2,6-dichlorobenzoyl)-1-naphthylphosphine oxide, bis(2,6-dimethoxybenzoyl)phenylphosphine oxide, bis(2,6-dimethoxybenzoyl)-2,4,4-trimethylpentylphosphine oxide, bis(2,6-dimethoxybenzoyl)-2,5-dimethylphenylphosphine oxide, bis(2,4,6-trimethylbenzoyl)phenylphosphine oxide, and bis(2,5,6-trimethylbenzoyl)-2,4,4-trimethylpentylphosphine oxide. Furthermore, compounds described in Japanese Patent Application Laid-Open No. 2000-159621 can be mentioned.

[0039] Among these (bis)acylphosphine oxides, 2,4,6-trimethylbenzoyldiphenylphosphine oxide, 2,4,6-trimethylbenzoylmethoxyphenylphosphine oxide, bis(2,4,6-trimethylbenzoyl)phenylphosphine oxide, and 2,4,6-trimethylbenzoylphenylphosphine oxide sodium salt are particularly preferably used as the photopolymerization initiator (B).

[0040] Examples of α-diketones include diacetyl, benzil, camphorquinone, 2,3-pentanedione, 2,3-octanedione, 9,10-phenanthrenequinone, 4,4′-oxybenzil, and acenaphthenequinone. Among them, camphorquinone is particularly preferred when a light source in the visible light region is used.

[0041] Examples of the germanium compound include monoacylgermanium compounds such as benzoyltrimethylgermanium (IV); and diacylgermanium compounds such as dibenzoyldiethylgermanium and bis(4-methoxybenzoyl)diethylgermanium.

[0042] The content of the photopolymerization initiator (B) in the resin composition for photomodeling of the present invention is not particularly limited as long as the effects of the present invention are exhibited. From the perspective of the curability of the resulting resin composition for photomodeling, it is preferably 0.01 to 20 parts by mass relative to 100 parts by mass of the total amount of the polymerizable compound. If the content of the photopolymerization initiator (B) is less than 0.01 parts by mass, there is a possibility that polymerization will not proceed sufficiently and a three-dimensional object cannot be obtained. The content of the photopolymerization initiator (B) is more preferably 0.05 parts by mass or more, further preferably 0.1 parts by mass or more, and particularly preferably 0.5 parts by mass or more relative to the aforementioned total amount of 100 parts by mass. On the other hand, if the content of the photopolymerization initiator (B) exceeds 20 parts by mass, if the solubility of the photopolymerization initiator itself is low, it may cause precipitation from the resin composition for photomodeling. The content of the photopolymerization initiator (B) is more preferably 15 parts by mass or less, further preferably 10 parts by mass or less, and particularly preferably 5.0 parts by mass or less relative to the aforementioned total amount of 100 parts by mass.

[0043] [Polymerizable compound (C) having a homopolymer Tg of less than 37°C] The photomodeling resin composition of the present invention preferably contains a polymerizable compound (C) having a homopolymer Tg of less than 37°C (hereinafter sometimes referred to as "polymerizable compound (C)"). The polymerizable compound (C) is used in the photomodeling resin composition of the present invention to further impart flexibility and water resistance to the cured product of the photomodeling resin composition.

[0044] The polymerizable compound (C) in the present invention can use a monofunctional polymerizable monomer having one polymerizable group and / or a polyfunctional polymerizable monomer having two or more polymerizable groups. Examples of the polymerizable compound (C) include a monofunctional or polyfunctional urethanized (meth) acrylic compound (C1) (hereinafter referred to as "urethanized (meth) acrylic compound (C1)"), a monofunctional or polyfunctional (meth) acrylic ester compound (C2) (hereinafter referred to as "(meth) acrylic ester compound (C2)") not having a urethanate bond, and the like. Among them, from the viewpoint of excellent curability of the resin composition for photomolding, the polymerizable compound (C) preferably contains a monofunctional or polyfunctional urethanized (meth) acrylic compound (C1), and from the viewpoint of excellent toughness and water resistance of the obtained cured product, it is more preferable to contain a polyfunctional urethanized (meth) acrylic compound. The polymerizable compound (C) can be used alone or in combination of two or more.

[0045] The polymerizable compound (C) in the present invention is primarily characterized by a homopolymer Tg of less than 37°C. By maintaining a homopolymer Tg of less than 37°C, a structure with moderate flexibility is introduced, enabling the formation of a three-dimensional shaped article with good toughness. From the perspective of toughness, the homopolymer Tg of the polymerizable compound (C) is preferably 25°C or less, more preferably 15°C or less.

[0046] Among the (meth)acrylate compounds (C2), examples of the monofunctional (meth)acrylate compounds include ethoxylated o-phenylphenol (meth)acrylate, ethoxylated m-phenylphenol (meth)acrylate, ethoxylated p-phenylphenol (meth)acrylate, propoxylated o-phenylphenol (meth)acrylate, propoxylated m-phenylphenol (meth)acrylate, propoxylated p-phenylphenol (meth)acrylate, butoxylated o-phenylphenol (meth)acrylate, butoxylated m-phenylphenol (meth)acrylate, butoxylated p-phenylphenol (meth)acrylate, (meth)acrylate o-phenoxybenzyl (meth)acrylate, m-phenoxybenzyl (meth)acrylate, p-phenoxybenzyl (meth)acrylate, 2-(o-phenoxyphenyl)ethyl (meth)acrylate, 2-(m-phenoxyphenyl)ethyl (meth)acrylate, 2-(p-phenoxyphenyl)ethyl (meth)acrylate, 3-(o-phenoxyphenyl)propyl (meth)acrylate, 3-(m-phenoxyphenyl)propyl (meth)acrylate, 3-(p-phenoxyphenyl)propyl (meth)acrylate, 4-(o-phenoxyphenyl)butyl (meth)acrylate, 4-(m-phenoxyphenyl)butyl (meth)acrylate, 4-(p-phenoxyphenyl)butyl (meth)acrylate , 5-(o-phenoxyphenyl)pentyl (meth)acrylate, 5-(m-phenoxyphenyl)pentyl (meth)acrylate, 5-(p-phenoxyphenyl)pentyl (meth)acrylate, 6-(o-phenoxyphenyl)hexyl (meth)acrylate, 6-(m-phenoxyphenyl)hexyl (meth)acrylate, 6-(p-phenoxyphenyl)hexyl (meth)acrylate and other monofunctional (meth)acrylate compounds containing aromatic rings; undecyl (meth)acrylate, lauryl (meth)acrylate, tridecyl (meth)acrylate, tetradecyl (meth)acrylate, pentadecyl (meth)acrylate, cetyl (meth)acrylate, (meth)acrylate Aliphatic monofunctional (meth)acrylate compounds such as palmitoleyl (meth)acrylate, heptadecyl (meth)acrylate, oleyl (meth)acrylate, stearyl (meth)acrylate, isostearyl (meth)acrylate, 4-hydroxybutyl (meth)acrylate, 6-hydroxyhexyl (meth)acrylate, 10-hydroxydecyl (meth)acrylate, glycerol mono(meth)acrylate, and erythritol mono(meth)acrylate; and heterocyclic ring-containing monofunctional (meth)acrylate compounds such as 1,2,2,6,6-pentamethyl-4-piperidinyl (meth)acrylate and 2,2,6,6-tetramethyl-4-piperidinyl (meth)acrylate. These may be used alone or in combination of two or more.Among these, from the viewpoint of excellent curability of the resin composition for photomodeling and the toughness of the cured product, monofunctional (meth)acrylate compounds having an aromatic ring are preferred, and o-phenoxybenzyl acrylate, m-phenoxybenzyl acrylate, p-phenoxybenzyl acrylate, 2-(o-phenoxyphenyl)ethyl acrylate, 2-(m-phenoxyphenyl)ethyl acrylate, 2-(p-phenoxyphenyl)ethyl acrylate, ethoxylated-o-phenylphenol (meth)acrylate, ethoxylated-m-phenylphenol (meth)acrylate, and ethoxylated-p-phenylphenol (meth)acrylate are more preferred. o-phenoxybenzyl acrylate, m-phenoxybenzyl acrylate, p-phenoxybenzyl acrylate, and ethoxylated-o-phenylphenol (meth)acrylate are even more preferred. o-phenoxybenzyl acrylate, m-phenoxybenzyl acrylate, p-phenoxybenzyl acrylate, and ethoxylated-o-phenylphenol (meth)acrylate are particularly preferred. o-phenoxybenzyl acrylate, m-phenoxybenzyl acrylate, and ethoxylated-o-phenylphenol (meth)acrylate are particularly preferred. m-phenoxybenzyl acrylate and ethoxylated-o-phenylphenol (meth)acrylate are most preferred.

[0047] Among the aforementioned (meth)acrylate compounds (C2), examples of the polyfunctional (meth)acrylate compounds include tetraethylene glycol di(meth)acrylate, polyethylene glycol di(meth)acrylate, cyclohexanedimethanol di(meth)acrylate, alkoxylated hexanediol di(meth)acrylate, ethoxylated bisphenol A di(meth)acrylate (ethylene oxide (EO) addition number: 10 mol%), ethoxylated bisphenol A di(meth)acrylate (EO addition number: 20 mol%), and ethoxylated neopentyl glycol di(meth)acrylate.

[0048] The content of the polymerizable compound (C) in the photomodeling resin composition of the present invention is preferably 1 to 69% by mass of the total amount of the polymerizable compound. From the perspective of achieving superior moldability, the flexibility, toughness, and water resistance of the cured product, the content of the polymerizable compound (C) is more preferably 2.5% by mass or greater, and even more preferably 5% by mass or greater. Furthermore, from the perspective of achieving superior moldability, the flexibility, toughness, and water resistance of the cured product, the content is more preferably 65% ​​by mass or less, and even more preferably 50% by mass or less.

[0049] The urethanized (meth)acrylic compound (C1) in the present invention can be easily synthesized by, for example, allowing a polyol containing a polymer backbone described below to undergo an addition reaction with a compound having an isocyanate group (—NCO) and a (meth)acrylic compound having a hydroxyl group (—OH). Alternatively, the urethanized (meth)acrylic compound (C1) can be easily synthesized by allowing a (meth)acrylic compound having a hydroxyl group to undergo a ring-opening addition reaction with a lactone or an alkylene oxide, followed by an addition reaction of the resulting compound having a hydroxyl group at one terminal with a compound having an isocyanate group.

[0050] The urethanized (meth)acrylic compound (C1) is preferably a (meth)acrylate containing, in one molecule, at least one structure (polymer backbone) selected from the group consisting of polyesters, polycarbonates, polyurethanes, polyethers, polyconjugated dienes, and hydrogenated polyconjugated dienes, and a urethane bond. More preferably, it is a (meth)acrylate having, in the molecule, a polyol moiety selected from the group consisting of polyesters, polycarbonates, polyurethanes, polyethers, polyconjugated dienes, and hydrogenated polyconjugated dienes having a structure derived from an aliphatic diol unit having 4 to 18 carbon atoms and a branched structure, and a urethane bond. Among the above structures, examples of polyesters include polymers of dicarboxylic acids (aromatic dicarboxylic acids such as isophthalic acid and isophthalic acid; unsaturated aliphatic dicarboxylic acids such as maleic acid) and aliphatic diols having 2 to 18 carbon atoms, polymers of dicarboxylic acids (saturated aliphatic dicarboxylic acids such as adipic acid and sebacic acid) and aliphatic diols having 2 to 18 carbon atoms, polymers of β-propiolactone, polymers of γ-butyrolactone, polymers of δ-valerolactone, polymers of ε-caprolactone, and copolymers thereof. Preferred are polymers of dicarboxylic acids (aromatic dicarboxylic acids such as phthalic acid and isophthalic acid; unsaturated aliphatic dicarboxylic acids such as maleic acid) and aliphatic diols having 2 to 12 carbon atoms, and polymers of dicarboxylic acids (saturated aliphatic dicarboxylic acids such as adipic acid and sebacic acid) and aliphatic diols having 2 to 12 carbon atoms. Examples of polycarbonates include those derived from aliphatic diols having 2 to 18 carbon atoms, polycarbonates derived from bisphenol A, and polycarbonates derived from aliphatic diols having 2 to 18 carbon atoms and bisphenol A. Preferred examples include polycarbonates derived from aliphatic diols having 2 to 12 carbon atoms, polycarbonates derived from bisphenol A, and polycarbonates derived from aliphatic diols having 2 to 12 carbon atoms and bisphenol A. Examples of polyurethanes include polymers of aliphatic diols having 2 to 18 carbon atoms and diisocyanates having 1 to 18 carbon atoms. Preferred examples include polymers of aliphatic diols having 2 to 12 carbon atoms and diisocyanates having 1 to 12 carbon atoms. Examples of polyethers include polyethylene glycol, polypropylene glycol, polybutylene glycol, and poly(1-methylbutylene glycol). Examples of polyconjugated dienes and hydrogenated polyconjugated dienes include 1,4-polybutadiene, 1,2-polybutadiene, polyisoprene, poly(butadiene-isoprene), poly(butadiene-styrene), poly(isoprene-styrene), polyfarnesene, and hydrogenated forms thereof. Among these, polyester structures are preferred from the perspective of excellent toughness. Furthermore, from the perspective of excellent water resistance and toughness, the polyester structure preferably contains a diol moiety having a structure derived from an aliphatic diol unit having 4 to 18 carbon atoms and a phthalate ester. Furthermore, from the perspective of excellent water resistance and styling properties, the polyester structure preferably contains a polyol moiety having a structure derived from an aliphatic diol unit having 4 to 12 carbon atoms and a sebacic acid ester.In the production of the urethanized (meth)acrylic compound (C1), a polyol having the aforementioned polymer skeleton can be used.

[0051] Examples of the compound having an isocyanate group include hexamethylene diisocyanate (HDI), toluene diisocyanate (TDI), xylene diisocyanate (XDI), diphenylmethane diisocyanate (MDI), isophorone diisocyanate (IPDI), trimethylhexamethylene diisocyanate (TMHMDI), tricyclodecane diisocyanate (TCDDI), and adamantane diisocyanate (ADI).

[0052] Examples of the (meth)acrylic acid compound having a hydroxyl group include hydroxy(meth)acrylate compounds such as 2-hydroxyethyl(meth)acrylate, 2-hydroxypropyl(meth)acrylate, 2-hydroxybutyl(meth)acrylate, 6-hydroxyhexyl(meth)acrylate, 10-hydroxydecyl(meth)acrylate, 3-chloro-2-hydroxypropyl(meth)acrylate, 2-hydroxy-3-phenoxypropyl(meth)acrylate, glycerol mono(meth)acrylate, 2-hydroxy-3-acryloyloxypropyl(meth)acrylate, 2,2-bis[4-[3-(meth)acryloyloxy-2-hydroxypropoxy]phenyl]propane, 1,2-bis[3-(meth)acryloyloxy-2-hydroxypropoxy]ethane, pentaerythritol tri(meth)acrylate, and tri- or tetra(meth)acrylate of dipentaerythritol; and hydroxy(meth)acrylamide compounds such as N-hydroxyethyl(meth)acrylamide and N,N-bis(2-hydroxyethyl)(meth)acrylamide.

[0053] Examples of the aliphatic diol unit having 4 to 18 carbon atoms and having a branched structure include 2-methyl-1,3-propanediol, 2,2-diethyl-1,3-propanediol, 1,3-butanediol, 2-methyl-1,4-butanediol, neopentyl glycol, 3-methyl-1,5-pentanediol, 2-methyl-1,8-octanediol, 2,7-dimethyl-1,8-octanediol, 2-methyl-1,9-nonanediol, 2,8-dimethyl-1,9-nonanediol, 2-methyl-1,10-decanediol, 2,9-dimethyl-1,10-decanediol, and 2-methyl-1,11-undecanediol. diol, 2,10-dimethyl-1,11-undecandiol, 2-methyl-1,12-dodecanediol, 2,11-dimethyl-1,12-dodecanediol, 2-methyl-1,13-tridecanediol, 2,12-dimethyl-1,13-tridecanediol, 2-methyl-1,14-tetradecanediol, 2,13-dimethyl-1,14-tetradecanediol, 2-methyl-1,15-pentadecandiol, 2,14-dimethyl-1,15-pentadecandiol, 2-methyl-1,16-hexadecanediol, 2,15-dimethyl-1,16-hexadecanediol, etc. Among these, from the viewpoint of excellent curability and low viscosity of the photomodeling resin composition, aliphatic diols having 5 to 12 carbon atoms and having a methyl group as a side chain, such as 2-methyl-1,4-butanediol, 3-methyl-1,5-pentanediol, 2-methyl-1,8-octanediol, 2,7-dimethyl-1,8-octanediol, 2-methyl-1,9-nonanediol, and 2,8-dimethyl-1,9-nonanediol, are preferably used as the polyol component. 2-methyl-1,4-butanediol, 3-methyl-1,5-pentanediol, 2-methyl-1,8-octanediol, and 2,7-dimethyl-1,8-octanediol are more preferred, and 3-methyl-1,5-pentanediol and 2-methyl-1,8-octanediol are even more preferred.

[0054] The addition reaction of the compound having an isocyanate group and the (meth)acrylic compound having a hydroxyl group can be carried out by a known method and is not particularly limited.

[0055] Examples of the urethanized (meth)acrylic compound (C1) include reaction products of any combination of a polyol having at least one structure selected from the group consisting of polyester, polycarbonate, polyurethane, polyether, polyconjugated diene, and hydrogenated polyconjugated diene, a compound having an isocyanate group, and a (meth)acrylic compound having a hydroxyl group.

[0056] From the viewpoint of viscosity and strength, the weight average molecular weight (Mw) of the urethanized (meth)acrylic compound (C1) is preferably 1,000 to 30,000, more preferably 1,500 to 15,000, even more preferably 1,500 to 9,000, even more preferably 1,500 to 8,000, particularly preferably 2,000 to 5,000, and most preferably 2,500 to 4,500. The weight average molecular weight (Mw) in the present invention refers to the polystyrene-equivalent weight average molecular weight determined by gel permeation chromatography (GPC).

[0057] The content of the urethanized (meth)acrylic compound (C1) in the resin composition for photomodeling of the present invention is preferably 1 to 69% by mass of the total amount of the polymerizable compounds. From the viewpoint of achieving better modeling properties and the flexibility, toughness, and water resistance of the cured product, it is more preferably 5 to 60% by mass, and even more preferably 10 to 50% by mass.

[0058] The photomodeling resin composition of the present invention may contain other polymerizable compounds in addition to the polymerizable compound (A) and the polymerizable compound (C), or the polymerizable compound may consist essentially of only the polymerizable compound (A) and the polymerizable compound (C). "The polymerizable compound consists essentially of only the polymerizable compound (A) and the polymerizable compound (C)" means that the content of the other polymerizable compounds other than the polymerizable compound (A) and the polymerizable compound (C) is less than 10.0% by mass, preferably less than 5.0% by mass, more preferably less than 1.0% by mass, further preferably less than 0.1% by mass, and particularly preferably less than 0.01% by mass, relative to the total amount of the polymerizable compounds contained in the photomodeling resin composition.

[0059] As a suitable embodiment, there is a resin composition for photomodeling in which the polymerizable compound consists essentially only of the polymerizable compound (A) and the polymerizable compound (C), and the polymerizable compound (A) contains only the monofunctional polymerizable monomer (A1). As another suitable embodiment, there is a resin composition for photomodeling in which the polymerizable compound consists essentially only of the polymerizable compound (A) and the polymerizable compound (C), the polymerizable compound (A) contains the monofunctional polymerizable monomer (A1) and the polyfunctional polymerizable monomer (A2), and the polymerizable compound (C) contains only the urethanized (meth)acrylic compound (C1). As another suitable embodiment, there is a resin composition for photomodeling in which the polymerizable compound consists essentially only of the polymerizable compound (A) and the polymerizable compound (C), the polymerizable compound (A) contains the monofunctional polymerizable monomer (A1) and the polyfunctional polymerizable monomer (A2), and the polymerizable compound (C) contains the urethanized (meth)acrylic compound (C1) and the (meth)acrylate compound (C2). Furthermore, as another suitable embodiment, there can be mentioned a resin composition for photomodeling containing a polymerizable compound (A) and a photopolymerization initiator (B), having a tan δ of 0.3 or less at 37°C after curing, and substantially no (meth)acrylamide urethane oligomer. In the aforementioned suitable embodiment, the content of the (meth)acrylamide urethane oligomer is less than 1.0% by mass, preferably less than 0.1% by mass, and more preferably less than 0.01% by mass. In any of the aforementioned suitable embodiments, the amount and type of each component can be appropriately changed according to the description of this specification, and optional components can be added or removed. In addition, in any of the aforementioned suitable embodiments, the composition of each resin composition for photomodeling and the values ​​of various properties (tan δ at 37°C after curing, tan δ at 200°C, peak temperature of tan δ at 37°C, flexural modulus, flexural strength, etc.) can be appropriately changed to combine them.

[0060] The resin composition for photomodeling of the present invention is not particularly limited as long as it contains the polymerizable compound (A) and the photopolymerization initiator (B) and has a tan δ at 37° C. after curing that satisfies a specific range, and can be produced by a known method.

[0061] The resin composition for photomolding of the present invention may contain a polymerization accelerator for the purpose of improving photocurability, within the scope of not impairing the main purpose of the present invention. Examples of polymerization accelerators include amine compounds such as tertiary amines such as ethyl 4-(N,N-dimethylamino)benzoate, methyl 4-(N,N-dimethylamino)benzoate, n-butoxyethyl 4-(N,N-dimethylamino)benzoate, 2-(methacryloyloxy)ethyl 4-(N,N-dimethylamino)benzoate, 4-(N,N-dimethylamino)benzophenone, and butyl 4-(N,N-dimethylamino)benzoate. The polymerization accelerators may be used alone or in combination of two or more. Among these, from the viewpoint of imparting excellent curability to the photomodeling resin composition, it is preferred to use at least one selected from ethyl 4-(N,N-dimethylamino)benzoate, n-butoxyethyl 4-(N,N-dimethylamino)benzoate, and 4-(N,N-dimethylamino)benzophenone.

[0062] Fillers may be further blended into the photomodeling resin composition of the present invention to adjust the properties of the paste or to modify the surface properties or strength of the cured product of the photomodeling resin composition. Examples of fillers include organic fillers, inorganic fillers, and organic-inorganic composite fillers. A single filler may be used alone, or two or more may be used in combination.

[0063] Examples of materials for organic fillers include polymethyl methacrylate, polyethyl methacrylate, methyl methacrylate-ethyl methacrylate copolymer, cross-linked polymethyl methacrylate, cross-linked polyethyl methacrylate, polyester, polyamide, polycarbonate, polyphenylene ether, polyoxymethylene, polyvinyl chloride, polystyrene, polyethylene, polypropylene, chloroprene rubber, nitrile rubber, ethylene-vinyl acetate copolymer, styrene-butadiene copolymer, acrylonitrile-styrene copolymer, and acrylonitrile-styrene-butadiene copolymer. These can be used alone or in combination of two or more. The shape of the organic filler is not particularly limited, and the particle size of the filler can be appropriately selected for use. From the viewpoints of the operability and mechanical strength of the resulting light-molding resin composition, the average particle size of the organic filler is preferably 0.001 to 50 μm, more preferably 0.001 to 10 μm, and even more preferably 0.001 to 1.0 μm.

[0064] Examples of materials for the inorganic filler include quartz, silica, alumina, silica-titania, silica-titania-baria, silica-zirconia, silica-alumina, lanthanum glass, borosilicate glass, soda glass, barium glass, strontium glass, glass ceramics, aluminosilicate glass, barium boroaluminosilicate glass, strontium boroaluminosilicate glass, fluoroaluminosilicate glass, calcium fluoroaluminosilicate glass, strontium fluoroaluminosilicate glass, barium fluoroaluminosilicate glass, and strontium calcium fluoroaluminosilicate glass. These materials may be used alone or in combination. The shape of the inorganic filler is not particularly limited, and irregularly shaped fillers or spherical fillers may be appropriately selected and used. From the viewpoints of the operability and mechanical strength of the resulting light-shaping resin composition, the average particle size of the inorganic filler is preferably 0.001 to 50 μm, more preferably 0.001 to 10 μm, and even more preferably 0.001 to 1.0 μm.

[0065] To adjust the fluidity of the resin composition for photomodeling, the inorganic filler may be pre-surface treated with a known surface treatment agent such as a silane coupling agent, if necessary, before use. Examples of the surface treatment agent include vinyltrimethoxysilane, vinyltriethoxysilane, vinyltrichlorosilane, vinyltris(β-methoxyethoxy)silane, γ-methacryloyloxypropyltrimethoxysilane, 8-methacryloyloxyoctyltrimethoxysilane, 11-methacryloyloxyundecyltrimethoxysilane, γ-glycidoxypropyltrimethoxysilane, γ-mercaptopropyltrimethoxysilane, and γ-aminopropyltriethoxysilane.

[0066] The organic-inorganic composite filler used in the present invention refers to a filler obtained by pre-adding monomer components to the above-mentioned inorganic filler, polymerizing it after making it into a paste, and crushing it. As the aforementioned organic-inorganic composite filler, for example, TMPT filler (a material obtained by mixing trimethylolpropane trimethacrylate with a silica filler, polymerizing it, and then crushing it) can be used. The shape of the aforementioned organic-inorganic composite filler is not particularly limited, and the particle size of the filler can be appropriately selected for use. From the viewpoint of the operability and mechanical strength of the obtained light shaping resin composition, the average particle size of the aforementioned organic-inorganic composite filler is preferably 0.001 to 50 μm, more preferably 0.001 to 10 μm, and even more preferably 0.001 to 1.0 μm.

[0067] It should be noted that, in this specification, the average particle size of a filler refers to the average primary particle size, which can be obtained by laser diffraction and scattering methods or electron microscopic observation of particles. Specifically, the laser diffraction and scattering method is convenient for measuring the particle size of particles larger than 0.1 μm, while electron microscopic observation is convenient for measuring the particle size of ultrafine particles smaller than 0.1 μm. The aforementioned 0.1 μm is a value measured by the laser diffraction and scattering method.

[0068] Specifically, the laser diffraction scattering method can be measured on a volume basis using, for example, a laser diffraction particle size distribution analyzer (SALD-2300: manufactured by Shimadzu Corporation) using a 0.2% sodium hexametaphosphate aqueous solution as a dispersion medium.

[0069] Specifically, electron microscopic observation can be performed by, for example, taking a photograph of the particles using an electron microscope (S-4000, manufactured by Hitachi, Ltd.) and measuring the particle size of 200 or more particles observed within a unit field of view of the photograph using image analysis particle size distribution measurement software (Mac-View (manufactured by Mac-Tech Co., Ltd.)). In this case, the particle size is calculated as the arithmetic mean of the maximum and minimum lengths of the particles, and the average primary particle size is calculated from the number of particles and their particle sizes.

[0070] The light shaping resin composition of the present invention may contain a polymer for modifying the properties of the light shaping resin composition, without prejudice to the main purpose of the present invention, such as flexibility and fluidity. For example, natural rubber, synthetic polyisoprene rubber, liquid polyisoprene rubber and its hydride, polybutadiene rubber, liquid polybutadiene rubber and its hydride, styrene-butadiene rubber, chloroprene rubber, ethylene-propylene rubber, acrylic rubber, isoprene-isobutylene rubber, acrylonitrile-butadiene rubber, or a styrene-based elastomer may be added. Specific examples of other polymers that may be added include polystyrene-polyisoprene-polystyrene block copolymers, polystyrene-polybutadiene-polystyrene block copolymers, poly(α-methylstyrene)-polybutadiene-poly(α-methylstyrene) block copolymers, poly(p-methylstyrene)-polybutadiene-poly(p-methylstyrene) block copolymers, or their hydrides.

[0071] The resin composition for light shaping of the present invention may contain a softener as needed. Examples of the softener include petroleum-based softeners such as paraffin-based, cycloparaffin-based, and aromatic process oils; and plant oil-based softeners such as paraffin, peanut oil, and rosin. These softeners may be used alone or in combination of two or more. The amount of the softener is not particularly limited, provided it does not impair the present invention; however, it is generally 200 parts by mass or less, preferably 100 parts by mass or less, relative to 100 parts by mass of the total amount of the polymerizable compound.

[0072] The photopolymerization resin composition of the present invention may contain a chemical polymerization initiator to improve curability, without prejudice to the scope of the present invention. Organic peroxides and azo compounds are preferably used. The organic peroxides and azo compounds used as chemical polymerization initiators are not particularly limited, and known compounds can be used. Representative organic peroxides include ketone peroxides, hydroperoxides, diacyl peroxides, dialkyl peroxides, peroxyketals, peroxyesters, and peroxydicarbonates.

[0073] The photopolymerization resin composition of the present invention may also contain a known stabilizer to inhibit degradation or adjust photocurability. Examples of such stabilizers include polymerization inhibitors, UV absorbers, and antioxidants. Stabilizers may be used alone or in combination of two or more.

[0074] Examples of the polymerization inhibitor include hydroquinone, hydroquinone monomethyl ether, dibutylhydroquinone, dibutylhydroquinone monomethyl ether, 4-tert-butylcatechol, 2-tert-butyl-4,6-dimethylphenol, 2,6-di-tert-butylphenol, and 3,5-di-tert-butyl-4-hydroxytoluene. The content of the polymerization inhibitor is preferably 0.001 to 5.0 parts by mass, more preferably 0.01 to 5.0 parts by mass, and even more preferably 0.1 to 4.5 parts by mass, relative to 100 parts by mass of the total amount of the polymerizable compound.

[0075] The photomolding resin composition of the present invention may also contain known additives to adjust the color tone or paste properties. Examples of these additives include colorants (pigments, dyes), organic solvents, and thickeners. These additives may be used alone or in combination of two or more.

[0076] The resin composition for photomolding of the present invention is easy to shape when shaped by photomolding (especially bottom-up liquid tank photomolding), and can obtain a molded object with excellent deformation recovery, toughness and water resistance. In addition, it can also be applied to inkjet photomolding. Therefore, the resin composition for photomolding of the present invention and its cured product can be used for applications that take advantage of this advantage, and can be used for oral applications such as dental materials and sleep disorder treatment materials. As a dental material, it is particularly suitable for dental braces (dental braces, bite plates, dental splints, etc.) and denture base materials (clawless dentures). Furthermore, in addition to dental treatment applications such as dental braces and denture base materials, the resin composition for photomolding of the present invention can also be suitably used as a protective gear and mouth guard for sports against external forces. As a sleep disorder treatment material, it is particularly suitable for treatment devices for sleep apnea syndrome (oral braces (OA)). The shape of the cured product using the resin composition for photomolding of the present invention can be changed according to each application. In addition, the types and contents of the components (polymerizable compound (A), photopolymerization initiator (B), polymerizable compound (C) and various other components (polymerization accelerator, filler, polymer, softener, stabilizer, additives, etc.)) of the photomodeling resin composition of the present invention can be adjusted as needed according to each application such as dental crowns and denture base materials.

[0077] The resin composition for photomolding of the present invention can be used for various purposes by utilizing its characteristics, especially the fact that it has a small volume shrinkage rate and excellent molding accuracy when cured by light, and can obtain three-dimensional molded objects with excellent deformation recovery, toughness and water resistance of the cured product, and can further obtain other cured products. It can be used, for example, for the production of three-dimensional molded objects using optical three-dimensional molding methods, the production of various three-dimensional molded objects such as film-like objects or molds using cast molding or injection molding, covering purposes, vacuum forming molds, etc.

[0078] Among them, the resin composition for photomolding of the present invention is suitable for use in the above-mentioned optical three-dimensional molding method. In this case, it is possible to smoothly produce a three-dimensional molded object that has a small volume shrinkage during photocuring, excellent molding accuracy, and excellent toughness and water resistance.

[0079] Another embodiment of the present invention includes a method for producing a three-dimensional object by an optical three-dimensional molding method using any of the aforementioned resin compositions for optical molding. The optical three-dimensional molding method is preferably a bottom-up liquid tank optical molding method.

[0080] When the optical stereoscopic shaping resin composition of the present invention is used for optical stereoscopic shaping (especially bottom-up liquid tank optical shaping), any conventionally known optical stereoscopic shaping method and apparatus (e.g., optical shaping machines such as DIGITALWAX (registered trademark) 020D manufactured by DWS) can be used. The optical stereoscopic shaping method and apparatus are not particularly limited. From the perspective of the viscosity of the optical stereoscopic shaping resin composition, the optical stereoscopic shaping resin composition of the present invention is particularly suitable for bottom-up optical stereoscopic shaping apparatus (bottom-up liquid tank optical shaping apparatus). In the present invention, as the light energy for curing the resin, active energy light is preferably used. "Active energy light" refers to energy rays such as ultraviolet rays, electron beams, X-rays, radiation, and high frequencies that can cure the optical stereoscopic shaping resin composition. For example, the active energy light can be ultraviolet light having a wavelength of 300 to 420 nm. As the light source of the active energy light, there can be listed lasers such as Ar lasers and He-Cd lasers; lighting such as halogen lamps, xenon lamps, metal halide lamps, LEDs, mercury lamps, and fluorescent lamps, and lasers are particularly preferred. When laser light is used, the energy level can be increased and the molding time can be shortened. Moreover, the good focusing property of laser light can be utilized to obtain a three-dimensional object with high molding precision.

[0081] As described above, when performing optical three-dimensional molding using the optical molding resin composition of the present invention, conventionally known methods and conventionally known optical molding system devices can be employed without particular limitation. A representative example of an optical three-dimensional molding method preferably used in the present invention includes a method in which the target three-dimensional object is ultimately obtained by repeating the following steps: selectively irradiating the optical molding resin composition with active energy light in such a manner as to obtain a cured layer having a desired pattern, thereby forming a cured layer; and further supplying an uncured liquid optical molding resin composition and similarly irradiating it with active energy light to form and laminate a new cured layer continuous with the previously cured layer. The resulting three-dimensional object can be used as is, or, depending on the circumstances, can be further post-cured by light irradiation or heat treatment to further improve its mechanical properties or shape stability.

[0082] The flexural modulus of the cured product of the photomodeling resin composition of the present invention is preferably in the range of 0.3 to 3.0 GPa, more preferably in the range of 0.5 to 2.5 GPa, and even more preferably in the range of 0.8 to 2.0 GPa. A cured product with a flexural modulus of 3.0 GPa or less exhibits soft properties, and when used as a dental brace, it follows the teeth well, resulting in an excellent fit and a less prone to falling out due to bruxism (teeth grinding) during sleep. Furthermore, the flexural strength of the cured product of the photomodeling resin composition of the present invention is preferably 30 MPa or greater, more preferably 40 MPa or greater, and even more preferably 50 MPa or greater.

[0083] The structure, shape, and dimensions of the three-dimensional objects produced by the optical stereolithography method are not particularly limited and can be determined according to the intended use. Representative applications of the optical stereolithography method of the present invention include models used to verify design during the design process; models used to verify component functionality; resin molds used to create castings; basic models used to create molds; and direct molds for prototype molds. More specifically, models and processing models for precision parts, electrical / electronic components, furniture, architectural structures, automotive parts, various containers, castings, molds, master molds, and the like can be used. Example

[0084] Next, the present invention will be described in more detail with reference to examples. However, the present invention is not limited to these examples, and a person having common knowledge in the art can make various modifications within the scope of the technical concept of the present invention.

[0085] The components used in the resin compositions for photomodeling according to Examples and Comparative Examples are described below together with their abbreviations.

[0086] [Monofunctional polymerizable monomer (A1)] PMPMA: Pentamethylpiperidinyl methacrylate (manufactured by ADEKA Corporation, liquid, homopolymer Tg: 105°C) ACMO: N-acryloylmorpholine (manufactured by KJ Chemicals Co., Ltd., liquid, homopolymer Tg: 145°C).

[0087] [Multifunctional polymerizable monomer (A2)] TCDDMA: tricyclodecane dimethanol diacrylate (manufactured by Basque Industries, liquid, homopolymer Tg: 214°C) THIA: tris(2-hydroxyethyl)isocyanurate triacrylate (manufactured by Basque Industries, solid, homopolymer Tg: 272° C.).

[0088] [Photopolymerization initiator (B)] TPO: 2,4,6-trimethylbenzoyldiphenylphosphine oxide BAPO: bis(2,4,6-trimethylbenzoyl)phenylphosphine oxide.

[0089] [Polymerizable compound (C)] [Urethaned (meth)acrylic acid compound (C1)] Urethane-converted (meth)acrylic acid compounds (C1)-1 and (C1)-2: Urethane-converted (meth)acrylic acid compounds (C1) produced by Synthesis Examples 1 and 2 described later.

[0090] [(Meth)acrylate compound (C2)] POBA: m-phenoxybenzyl acrylate (manufactured by Kyoeisha Chemical Co., Ltd., colorless transparent liquid, homopolymer Tg: -35°C).

[0091] [Polymerization inhibitor] BHT: 3,5-di-tert-butyl-4-hydroxytoluene.

[0092] <Synthesis Example 1> [Production of urethanized (meth)acrylic acid compound (C1)-1] (1) Into a 5 L four-necked flask equipped with a stirrer, a temperature regulator, a thermometer, and a condenser, 250 g of isophorone diisocyanate and 0.15 g of di-n-butyltin dilaurate were added, and the mixture was heated to 70° C. while stirring.

[0093] (2) On the other hand, 2500 g of polyester polyol ("Kuraray Polyol (registered trademark) P-2050" manufactured by Kuraray Co., Ltd.; a polyol composed of sebacic acid and 3-methyl-1,5-pentanediol, weight-average molecular weight Mw: 2000) was added to a dropping funnel with a side tube, and the liquid in the dropping funnel was added dropwise to the flask in (1) above. It should be noted that while the solution in the flask in (1) above was stirred, the internal temperature of the flask was maintained at 65 to 75°C, and the addition was carried out at a constant rate over 4 hours. Furthermore, after the addition was completed, the mixture was stirred at the same temperature for 2 hours to allow the mixture to react.

[0094] (3) Next, while maintaining the internal temperature of the flask at 55 to 65°C, a liquid containing 150 g of 2-hydroxyethyl acrylate and 0.4 g of hydroquinone monomethyl ether uniformly dissolved in another dropping funnel was added dropwise at a constant rate over 2 hours. The solution in the flask was then reacted for 4 hours while maintaining the temperature of the solution in the flask at 70 to 80°C, thereby obtaining a urethanized (meth)acrylic compound (C1)-1. The weight average molecular weight Mw of the urethanized (meth)acrylic compound (C1)-1 as determined by GPC analysis was 2600, and the glass transition temperature of the cured product (Tg of the homopolymer of the urethanized (meth)acrylic compound (C1)-1) was -30°C.

[0095] <Synthesis Example 2> [Production of urethanized (meth)acrylic acid compound (C1)-2] (1) Into a 5 L four-necked flask equipped with a stirrer, a temperature regulator, a thermometer, and a condenser, 250 g of isophorone diisocyanate and 0.15 g of di-n-butyltin dilaurate were added, and the mixture was heated to 70° C. while stirring.

[0096] (2) On the other hand, 2500 g of polyester polyol ("Kuraray Polyol (registered trademark) P-2030" manufactured by Kuraray Co., Ltd.; a polyol composed of isophthalic acid and 3-methyl-1,5-pentanediol, weight-average molecular weight Mw: 2000) was added to a dropping funnel with a side tube, and the liquid in the dropping funnel was added dropwise to the flask in (1) above. It should be noted that while the solution in the flask in (1) above was stirred, the internal temperature of the flask was maintained at 65 to 75°C, and the addition was carried out at a constant rate over 4 hours. Furthermore, after the addition was completed, the mixture was stirred at the same temperature for 2 hours to allow the mixture to react.

[0097] (3) Next, while maintaining the internal temperature of the flask at 55 to 65°C, a liquid containing 150 g of 2-hydroxyethyl acrylate and 0.4 g of hydroquinone monomethyl ether uniformly dissolved in another dropping funnel was added dropwise at a constant rate over 2 hours. The solution in the flask was then reacted for 4 hours while maintaining the temperature of the solution in the flask at 70 to 80°C, thereby obtaining the urethanized (meth)acrylic compound (C1)-2. The weight average molecular weight Mw of the urethanized (meth)acrylic compound (C1)-2 as determined by GPC analysis was 2700, and the glass transition temperature of the cured product (Tg of the homopolymer of the urethanized (meth)acrylic compound (C1)-2) was 30°C.

[0098] [Examples 1 to 5 and Comparative Examples 1 to 4] The components were mixed in the amounts shown in Tables 1 and 2 at room temperature (20°C ± 15°C, JIS (Japanese Industrial Standards) Z8703: 1983) to prepare pastes in the form of photomodeling resin compositions according to Examples 1 to 5 and Comparative Examples 1 to 4.

[0099] <Styling> For each example and comparative example, a light shaping machine (DIGITALWAX (registered trademark) 020D manufactured by DWS) was used to shape test pieces (n = 5) measuring 3.3 mm thick, 10.0 mm wide, and 64 mm long, using a shaping pitch of 50 μm and a laser scanning speed of 4300 mm / sec. A sheet with the correct dimensions was shaped as "OK"; a three-dimensional object was not formed even once, as "Unable to shape." The resulting test pieces were used for the evaluations described below.

[0100] <Viscoelasticity (tan δ at 37°C and 200°C, tan δ Peak Temperature)> For the photomodeling resin compositions of the Examples and Comparative Examples, a photoirradiation device (Otoflash (registered trademark) G171 manufactured by EnvisionTEC) was used to flash 2000 times to produce a disk-shaped cured product having a diameter of 25 mm and a thickness of 1.0 mm. The cured product was then measured for tan δ at 37°C and 200°C and its peak temperature using a dynamic viscoelasticity measuring apparatus (rotational rheometer, AR2000 manufactured by They Instruments Japan Co., Ltd.) under measurement conditions of a load (force restraining the disk) of 10 N ± 1 N, a displacement (torsion distance) of 0.1%, and a frequency of 1 Hz. From the perspective of good deformation recovery, the tan δ at 37°C is preferably 0.2 or less, more preferably 0.15 or less, and even more preferably 0.1 or less. In addition, from the perspective of easily forming a cured product with good deformation recovery properties, tan δ at 200°C is preferably 0.5 or less, more preferably 0.4 or less, and even more preferably 0.3 or less. Furthermore, from the perspective of easily forming a cured product with good deformation recovery properties, the peak top temperature of tan δ is preferably 60°C or more, more preferably 80°C or more, and even more preferably 100°C or more.

[0101] <Deformation recovery (permanent deformation)> For the cured products of the photomolding resin compositions according to the examples and comparative examples, a photomolding machine (DIGITALWAX (registered trademark) 020D manufactured by DWS) was used to produce a sheet-like cured product having a length of 60 mm, a width of 20 mm, and a thickness of 1.0 mm under the conditions of a molding pitch of 50 μm and a laser scanning speed of 4300 mm / sec. The cured product was punched out using a dumbbell-shaped No. 8 punching blade in accordance with JIS K 6251:2010 (Rubber vulcanized and thermoplastic rubber - Methods for calculating tensile properties) to produce tensile test specimens (n=5). The obtained test specimens were used to evaluate permanent set as an indicator of deformation recovery. Specifically, a universal testing machine (EZ Test EZ-SX 500N manufactured by Shimadzu Corporation) was used to stretch the sheet by 0.5 mm under the conditions of a chuck distance of 10 mm and a crosshead speed of 20 mm / min. The crosshead was then returned to its original position at a crosshead speed of 10 mm / min, and the permanent set at the time when the stress reached zero was measured. The average values ​​of the measured values ​​are shown in Tables 1 and 2. In this test, the permanent strain is preferably 0.1 mm or less, more preferably 0.075 mm or less, and even more preferably 0.050 mm or less.

[0102] <Toughness (flexural modulus, flexural strength, breaking point displacement)> For the cured products of the photomolding resin compositions according to the Examples and Comparative Examples, test pieces (64.0 mm in length, 10.0 mm in width, and 3.3 mm in thickness) with the dimensions specified in JIS T 6501:2012 (Acrylic Resins for Denture Bases) and used for evaluation of moldability were prepared under conditions of a molding pitch of 50 μm and a laser scanning speed of 4300 mm / sec. After the test pieces were stored in air for one day, bending strength tests were performed and evaluated, with the values ​​used as initial values. Specifically, bending strength tests were conducted using a universal testing machine (Autograph AG-I 100 kN, manufactured by Shimadzu Corporation) at a support distance of 50 mm and a crosshead speed of 5 mm / min (n = 5). The average values ​​of the measured values ​​are shown in Tables 1 and 2. As the bending modulus of the test piece, it is preferably in the range of 0.3 to 3.0 GPa, more preferably in the range of 0.5 to 2.5 GPa, and further preferably in the range of 0.8 to 2.0 GPa. As the bending strength, it is preferably 30 MPa or more, more preferably 40 MPa or more, and further preferably 50 MPa or more. As for the breaking point displacement, it is preferred that no breaking occurs. Regarding the breaking point displacement, the case where no breaking occurs at the end or the breaking occurs when the displacement is 20 mm or more is recorded as good softness "○", the case where the breaking occurs when the displacement exceeds 10 mm and is less than 20 mm is recorded as medium softness "△", the case where the breaking occurs when the displacement is less than 10 mm is recorded as poor softness "×", and the above "△" is recorded as qualified.

[0103] <Water resistance> For the cured products of the light shaping resin compositions involved in each embodiment and each comparative example, which were produced in the same manner as the cured products produced in the measurement of toughness, the bending strength was measured in the same manner as the above-mentioned bending strength test after being immersed in water at 37°C for 168 hours (n=5). The measurement results of the bending strength in the above-mentioned toughness were taken as the initial bending strength, and the rate of change (reduction rate) of the bending strength after being immersed in water at 37°C for 168 hours relative to the initial bending strength was calculated. If the rate of change (reduction rate) of the bending strength is 10% or less, the water resistance is excellent, and if it is 7% or less, the water resistance is even better. The average values ​​of the calculated values ​​are shown in Tables 1 and 2. In Tables 1 and 2, the bending strength after being immersed in water at 37°C for 168 hours is shown as "bending strength after immersion."

[0104] Change rate (reduction rate) of flexural strength (%) = [{initial flexural strength (MPa) - flexural strength after immersion in water at 37°C for 168 hours (MPa)} / initial flexural strength (MPa)] × 100. [Table 1] [Table 2]

[0105] As shown in Tables 1 and 2, the photomolding resin compositions of Examples 1 to 5 exhibit excellent moldability, and the cured products exhibit excellent deformation recovery, toughness, and water resistance. In particular, the photomolding resin compositions of Examples 1 to 5 exhibit superior moldability compared to the resin composition of Comparative Example 1. Furthermore, the cured products of the photomolding resin compositions of Examples 1 to 5 exhibit superior deformation recovery compared to the cured products of the resin compositions of Comparative Examples 2 to 4. The cured products of the photomolding resin compositions of Examples 1 to 5 exhibit superior toughness and water resistance compared to the cured products of Comparative Examples 2 and 4.

[0106] Industrial applicability The photomolding resin composition of the present invention is easy to shape, and the cured product has excellent deformation recovery, toughness, and water resistance. Therefore, it is suitable for oral applications such as various dental materials (particularly dental crowns and denture base materials, especially orthodontic appliances and clasp-free dentures) or various sleep disorder treatment materials (particularly treatment devices for sleep apnea syndrome).

Claims

1. A resin composition for photomodeling, comprising a polymerizable compound (A) having a homopolymer glass transition temperature (Tg) of 37°C or higher and a photopolymerization initiator (B), wherein the resin composition for photomodeling has a tan δ of 0.3 or less at 37°C after curing. 2 . The resin composition for photomodeling according to claim 1 , wherein the peak top temperature of tan δ after curing is 60° C. or higher. 3 . The resin composition for photomodeling according to claim 1 , further comprising a polymerizable compound (C) having a homopolymer glass transition temperature (Tg) of less than 37° C. The resin composition for photomodeling according to any one of claims 1 to 3, wherein tan δ at 200°C after curing is 0.5 or less.

5. The resin composition for photomodeling according to any one of claims 1 to 4, wherein The polymerizable compound (A) contains a monofunctional polymerizable monomer (A1).

6. The resin composition for photomolding according to claim 5, wherein The monofunctional polymerizable monomer (A1) contains a monofunctional (meth)acrylate compound and / or a monofunctional (meth)acrylamide compound.

7. The resin composition for photomolding according to claim 6, wherein The monofunctional polymerizable monomer (A1) contains a monofunctional (meth)acrylate compound containing at least one selected from the group consisting of an aromatic ring-containing (meth)acrylate compound, an alicyclic (meth)acrylate compound, and a nitrogen atom-containing cyclic (meth)acrylate compound.

8. The resin composition for photomolding according to claim 7, wherein The monofunctional (meth)acrylate compound includes a nitrogen atom-containing cyclic (meth)acrylate compound.

9. The resin composition for photomolding according to claim 8, wherein The nitrogen-containing cyclic (meth)acrylate compound contains at least one selected from pentamethylpiperidinyl (meth)acrylate, tetramethylpiperidinyl (meth)acrylate, and 4-(pyrimidin-2-yl)piperazin-1-yl (meth)acrylate.

10. The resin composition for photomodeling according to any one of claims 1 to 9, wherein The polymerizable compound (A) contains a polyfunctional polymerizable monomer (A2).

11. The resin composition for photomolding according to claim 10, wherein The polyfunctional polymerizable monomer (A2) contains an aliphatic polyfunctional polymerizable monomer.

12. The resin composition for photomolding according to claim 10, wherein The polyfunctional polymerizable monomer (A2) contains an alicyclic polyfunctional polymerizable monomer.

13. The resin composition for photomolding according to claim 12, wherein The alicyclic multifunctional polymerizable monomer contains tricyclodecane dimethanol di(meth)acrylate.

14. The resin composition for photomodeling according to any one of claims 10 to 13, wherein The polyfunctional polymerizable monomer (A2) contains a heterocyclic ring-containing polyfunctional polymerizable monomer.

15. The resin composition for photomodeling according to any one of claims 3 to 14, wherein The polymerizable compound (C) contains a urethanized (meth)acrylic compound (C1).

16. The resin composition for photomolding according to claim 15, wherein The urethanized (meth)acrylic compound (C1) is a (meth)acrylate containing at least one structure selected from polyester, polycarbonate, polyurethane, polyether, polyconjugated diene, and hydrogenated polyconjugated diene, and a urethane bond in one molecule.

17. The resin composition for photomolding according to claim 15 or 16, wherein The urethanized (meth)acrylic compound (C1) is a (meth)acrylate containing a polyol portion and a urethane bond in one molecule, wherein the polyol portion is at least one selected from polyesters, polycarbonates, polyurethanes, polyethers, polyconjugated dienes, and hydrogenated polyconjugated dienes having a structure derived from a branched aliphatic diol unit having 4 to 18 carbon atoms. 18 . A dental material comprising a cured product of the photomodeling resin composition according to claim 1 .

19. A dental mouthpiece comprising a cured product of the photomodeling resin composition according to any one of claims 1 to 17.

20. A denture base material comprising a cured product of the photomodeling resin composition according to any one of claims 1 to 17.

21. A material for treating sleep disorders, comprising a cured product of the resin composition for photomodeling according to any one of claims 1 to 17.

22. A method for producing a three-dimensional object by an optical three-dimensional molding method using the resin composition for optical molding according to any one of claims 1 to 17.

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