Resin composition for photomodeling

Abstract

The present invention provides a resin composition for photomodeling, which has little odor, is easy to shape, and has excellent toughness and water resistance of the cured product when being shaped by photomodeling. The present invention relates to a resin composition for photomodeling, which contains: a compound (A) containing an α, β-unsaturated double bond group, the glass transition temperature (Tg) of its homopolymer is above 40°C, has multiple independent aromatic rings, and does not have a carbamate bond; a compound (B) containing an α, β-unsaturated double bond group, the glass transition temperature (Tg) of its homopolymer is lower than 40°C, has a cyclic structure, and has a normal pressure boiling point of 250°C or more; and a photopolymerization initiator (C).

Description

Technical Field

[0001] The present invention relates to a resin composition for photomolding. More specifically, the present invention can obtain a three-dimensional molded object with less odor, easy molding, excellent toughness and water resistance when molding by photomolding. It is particularly suitable for dental braces and denture base materials. Background Art

[0002] Patent document 1 discloses a method for manufacturing a three-dimensional object by supplying a necessary amount of controlled light energy to a liquid photocurable resin to cure it into a thin layer, supplying a further liquid photocurable resin thereon, and then irradiating light under control to cure it in a stacked layer into a thin layer, and repeating the above steps, i.e., the so-called optical three-dimensional molding method. Furthermore, its basic practical method is further proposed in Patent document 2, and since then, a large number of proposals have been proposed regarding the optical three-dimensional molding technology.

[0003] As a representative method for optically manufacturing three-dimensional objects, the method of liquid tank optical molding is generally used, in which the liquid surface of the liquid photocurable resin composition placed in the container is selectively irradiated with a computer-controlled ultraviolet laser in a manner to obtain a desired pattern, so that it is cured with a specified thickness to form a solid layer, and then a layer of liquid photocurable resin composition is supplied on the solid layer, and ultraviolet laser is also irradiated to cure it in the same manner as above, so as to form a continuous solid layer, and the above-mentioned stacking operation is repeated to manufacture a three-dimensional object of the final shape. When using this method, even if the shape of the object is quite complex, it is possible to simply and in a short time to manufacture the target three-dimensional object with good precision, so it has attracted much attention in recent years.

[0004] Furthermore, the three-dimensional objects obtained by the photomolding method have been expanded from simple concept models to test models, prototypes, etc., and the three-dimensional objects are increasingly required to have excellent molding accuracy. In addition to such characteristics, excellent characteristics that match the purpose are also required. In particular, in the field of dental materials, dental braces and denture bases have different shapes depending on the individual patient and are complex in shape, so the application of the photomolding method is expected.

[0005] Dental braces include the following devices: devices called dental braces worn on the teeth to correct the tooth arrangement, devices called dental braces worn to correct the jaw position, devices worn on the teeth at night to treat sleep apnea syndrome, devices worn on the teeth to suppress tooth wear caused by grinding, devices worn in the mouth to reduce trauma caused by large external forces applied to the teeth and jawbone during competition in contact sports, and devices worn in the mouth to protect the mandibular oral system and brain. It is a device that has been rapidly expanded in recent years in dental correction for good aesthetics or for removal when desired. In addition, sleep apnea syndrome is also a disease that has received attention in medical treatment, and its application has been rapidly promoted as a treatment tool.

[0006] Denture base material is the material used for the gum part when wearing dentures due to tooth loss. In recent years, with the increase in the elderly population, the demand for dentures has increased dramatically.

[0007] These dental braces and denture base materials are required to have toughness and water resistance. If toughness is impaired, the wearing feeling is poor, or the impact of external force and bite is directly applied to the jawbone. In addition, if it is easy to break, there is a problem that frequent re-making is required. Furthermore, if water resistance is impaired, there is a problem that the mechanical strength is reduced, the correction force or impact absorption is lost, or it becomes easy to break and cannot withstand practical use.

[0008] In addition, it is usually necessary to obtain an impression of the oral cavity when making dental braces and denture base materials, and therapeutic appliances for sleep apnea syndrome, but it has always been pointed out that there is a burden on patients due to its discomfort or that it requires skilled technicians to operate. In recent years, due to the development of digital technology, attempts have been made to apply optical intraoral scanning to impression acquisition, and attempts have been made to apply optical three-dimensional modeling in molding. When using a photocurable resin composition in modeling, generally speaking, there is a tendency to use a low-polarity monomer for a resin composition that exhibits flexibility and water resistance, so the curability becomes lower, and there is a tendency for the mechanical strength of the cured product to be poor. In particular, in optical three-dimensional modeling, the light irradiation time is extremely short, and each layer of modeling is exposed to oxygen, so the curing is particularly easy to become insufficient, and it has been difficult to balance mechanical strength, toughness, and water resistance. Furthermore, it is necessary to set a viscosity that can be used to model the resin composition, but in the case of using a low molecular weight monomer in order to reduce the viscosity, it is easy to produce odor. On the other hand, most monomers that exhibit mechanical strength are high-viscosity, and there is a problem of reduced modeling. Therefore, it is difficult to obtain a three-dimensional figure-forming resin composition as a whole that has a low viscosity while providing a cured product with excellent properties such as toughness and water resistance.

[0009] In this context, as a technology that has excellent molding accuracy, mechanical strength and swelling resistance of the cured product and is capable of optical three-dimensional molding, for example, Patent Document 3 proposes a resin composition for optical three-dimensional molding, which contains at least an oligomer having one or more α,β-unsaturated double bond groups and a compound containing α,β-unsaturated double bond groups having a ring structure of three or more rings as essential components.

[0010] Prior art literature

[0011] Patent Literature

[0012] Patent Document 1: Japanese Patent Application Laid-Open No. 56-144478

[0013] Patent Document 2: Japanese Patent Application Laid-Open No. 60-247515

[0014] Patent document 3: Japanese Patent Application Publication No. 2015-10169. Summary of the invention

[0015] Problems to be solved by the invention

[0016] The resin composition for optical three-dimensional modeling described in Patent Document 3 does not describe water resistance and odor at all, and a monomer having a significant odor is used in the examples.

[0017] Therefore, the object of the present invention is to provide a resin composition for photomolding which has little odor when molded by photomolding, is easy to mold, and has excellent toughness and water resistance of the cured product. In addition, the object is to provide a resin composition for photomolding which is particularly suitable for dental crowns and denture base materials.

[0018] Means for solving problems

[0019] That is, the present invention includes the following inventions.

[0020] [1] A resin composition for photopolymerization, comprising: a compound (A) containing an α,β-unsaturated double bond group, the homopolymer of which has a glass transition temperature (Tg) of 40°C or higher, has multiple independent aromatic rings, and does not have a urethane bond; a compound (B) containing an α,β-unsaturated double bond group, the homopolymer of which has a glass transition temperature (Tg) of less than 40°C, has a cyclic structure, and has a boiling point at normal pressure of 250°C or higher; and a photopolymerization initiator (C).

[0021] [2] The resin composition for photomodeling according to [1], wherein the compound (A) containing an α,β-unsaturated double bond group is a monofunctional compound.

[0022] [3] The resin composition for photomodeling according to [1], wherein the compound (A) containing an α,β-unsaturated double bond group is a monofunctional (meth)acrylate compound (A)-1.

[0023] [4] A resin composition for photomolding according to any one of [1] to [3], wherein the plurality of independent aromatic rings is a biphenyl skeleton, a diphenylmethyl skeleton, a 2,2-diphenylpropane skeleton, a triphenylmethyl skeleton, a diphenyl ether skeleton, a fluorene skeleton, a carbazole skeleton or a diphenylamine skeleton.

[0024] [5] A resin composition for photomolding according to any one of [1] to [3], wherein the plurality of independent aromatic rings is a biphenyl skeleton, a diphenylmethyl skeleton, a 2,2-diphenylpropane skeleton, a triphenylmethyl skeleton, a diphenylether skeleton, a fluorene skeleton or a diphenylamine skeleton.

[0025] [6] The resin composition for photomodeling according to any one of [1] to [3], wherein the plurality of independent aromatic rings are a triphenylmethyl skeleton or a fluorene skeleton.

[0026] [7] The resin composition for photomodeling according to any one of [1] to [6], wherein the compound (A) containing an α,β-unsaturated double bond group is at least one selected from triphenylmethyl (meth)acrylate, 9-(meth)acryloyloxyfluorene and 9-(meth)acryloyloxymethylfluorene.

[0027] [8] The resin composition for photomodeling according to any one of [1] to [7], wherein the compound (B) containing an α,β-unsaturated double bond group is a monofunctional compound.

[0028] [9] The resin composition for photomodeling according to any one of [1] to [8], wherein the compound (B) containing an α,β-unsaturated double bond group is a monofunctional (meth)acrylate compound (B)-1.

[0029]

[10] The resin composition for photomodeling according to any one of [1] to [9], wherein the cyclic structure is an aromatic ring.

[0030]

[11] The resin composition for photomolding according to any one of [1] to

[10] , wherein the compound (B) containing an α,β-unsaturated double bond group is at least one selected from 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.

[0031]

[12] The resin composition for photomodeling according to any one of [1] to

[11] , further comprising a urethane-containing (meth) acrylic compound (D) (except for the aforementioned compound (B) containing an α,β-unsaturated double bond group).

[0032]

[13] The resin composition for photomolding according to

[12] , wherein the urethanized (meth)acrylic compound (D) is a (meth)acrylate containing at least one structure selected from polyester, polycarbonate, polyurethane, polyether, polyconjugated diene and hydrogenated polyconjugated diene, and a urethanate bond in one molecule.

[0033]

[14] The resin composition for photomolding according to

[13] , wherein the urethane-modified (meth)acrylic compound (D) is a (meth)acrylate containing a polyol portion in one molecule, and the polyol portion is at least one selected from a polyester, a polycarbonate, a polyurethane, a polyether, a polyconjugated diene and a hydrogenated polyconjugated diene having a structure derived from an aliphatic diol unit (d) having 4 to 18 carbon atoms and a branched structure.

[0034]

[15] A dental material comprising a cured product of the photomodeling resin composition according to any one of [1] to

[14] .

[0035]

[16] A dental mouthpiece comprising a cured product of the photomolding resin composition according to any one of [1] to

[14] .

[0036]

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

[14] .

[0037]

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

[14] .

[0038]

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

[14] .

[0039] Effects of the Invention

[0040] The resin composition for photomolding of the present invention has little odor and is easy to mold when molded by photomolding, and the cured product has excellent toughness and water resistance. Therefore, it can be suitably used in various dental materials (especially dental caps and denture base materials) or various sleep disorder treatment materials (especially sleep apnea syndrome treatment devices). DETAILED DESCRIPTION

[0041] The resin composition for photomodeling of the present invention contains: a compound (A) containing an α,β-unsaturated double bond group, the homopolymer of which has a glass transition temperature (Tg) of 40°C or higher, has multiple independent aromatic rings, and has no urethane bond; a compound (B) containing an α,β-unsaturated double bond group, the homopolymer of which has a glass transition temperature (Tg) of less than 40°C, has a cyclic structure, and has a normal pressure boiling point of 250°C or higher; and a photopolymerization initiator (C). 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 by each component, and each physical property, etc.) can be appropriately combined.

[0042] [Compound (A) having an α,β-unsaturated double bond group and having a homopolymer glass transition temperature (Tg) of 40°C or higher, having multiple independent aromatic rings and having no urethane bond]

[0043] A compound (A) containing an α,β-unsaturated double bond group, having multiple independent aromatic rings and no urethane bonds (hereinafter sometimes referred to as "compound (A) containing an α,β-unsaturated double bond group") having a homopolymer glass transition temperature (Tg) of 40°C or above can form a three-dimensional shaped object with good toughness including strength by increasing the melting point (Tm) or glass transition temperature (Tg) of the shaped object after light irradiation.

[0044] The important thing about the compound (A) containing an α,β-unsaturated double bond group in the present invention is that the glass transition temperature (Tg) of its homopolymer is 40°C or higher. By making the glass transition temperature (Tg) of the homopolymer be 40°C or higher, a rigid structure is introduced, so that a three-dimensional shaped object with good strength can be formed. 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. It should be noted that in the present invention, the glass transition temperature (Tg) of the compound can be measured by a conventionally known method using a viscoelasticity measuring device (rheometer), a differential scanning calorimeter (DSC), etc. For example, the glass transition temperature (Tg) can be determined by measuring the dynamic viscoelasticity of the (meth)acrylic compound (A) using a rotational rheometer (manufactured by Thei Instruments Japan Co., Ltd., “AR2000”). In the 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, and the temperature at which tan δ reaches a peak is determined as the glass transition temperature (Tg).

[0045] The compound (A) containing an α,β-unsaturated double bond group in the present invention is important to have multiple independent aromatic rings. In this specification, "multiple independent aromatic rings" refers to a condensed ring compound that does not include a skeleton (naphthalene skeleton, phenanthrene skeleton, phenanthracene skeleton, anthracene skeleton, etc.) having two or more aromatic rings directly fused to each other. By having multiple independent aromatic rings, the solubility is excellent, and a rigid structure is introduced, so that a three-dimensional shaped object with good strength can be formed.

[0046] It is important that the compound (A) containing an α,β-unsaturated double bond group in the present invention does not have a urethane bond. In the case of having a urethane bond, the viscosity of the obtained three-dimensional modeling resin composition increases, and the modeling property decreases.

[0047] In this specification, α, β-unsaturated double bond groups refer to polymerizable groups such as (meth) acryloyl, vinyl, and styrene. In a suitable embodiment, the α, β-unsaturated double bond group is a (meth) acryloyl group. The compound (A) containing an α, β-unsaturated double bond group in the present invention is preferably a monofunctional compound from the viewpoint of excellent toughness of the resulting cured product, and more preferably a monofunctional (meth) acrylate compound (A)-1. In this specification, "monofunctional" means having one of the aforementioned polymerizable groups. It should be noted that in this specification, the expression "(meth) acrylic acid" is used to include both methacrylic acid and acrylic acid, and similar expressions such as "(meth) acryloyl" and "(meth) acrylate" are also the same.

[0048] As the structure having multiple independent aromatic rings, biphenyl skeleton, diphenylmethyl skeleton, 2,2-diphenylpropane skeleton, triphenylmethyl skeleton, diphenylether skeleton, fluorene skeleton, carbazole skeleton, diphenylamine skeleton can be cited. Among these, biphenyl skeleton, diphenylmethyl skeleton, 2,2-diphenylpropane skeleton, triphenylmethyl skeleton, diphenylether skeleton, fluorene skeleton or diphenylamine skeleton are preferred from the viewpoints of excellent solubility, low viscosity of the photo-molding resin composition, and excellent toughness of the cured product. Biphenyl skeleton, diphenylmethyl skeleton, 2,2-diphenylpropane skeleton, triphenylmethyl skeleton, diphenylether skeleton or fluorene skeleton are more preferred, and triphenylmethyl skeleton or fluorene skeleton is further preferred. The aforementioned "skeleton" can also be referred to as "base".

[0049] The independent multiple aromatic rings possessed by the compound (A) containing an α,β-unsaturated double bond group may have substituents such as an alkyl group, an alkoxy group, an ester group, an acyl group, an alkylamino group, a silyl group, a nitro group, a nitroso group, a halogen atom, etc. The number of substituents is not particularly limited, and is preferably 1 to 6, more preferably 1 to 4, further preferably 1 to 3, and particularly preferably 1 to 2. As the alkyl group and the alkylamino group, for example, a straight chain or branched alkyl group having 1 to 12 carbon atoms can be cited, specifically, a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, an isobutyl group, a sec-butyl group, a 2-methylpropyl group, a tert-butyl group, an n-pentyl group, an isopentyl group, a neopentyl group, etc. The number of carbon atoms of the alkyl group and the alkylamino group is preferably 1 to 6, more preferably 1 to 4, and further preferably 1 to 3.

[0050] Examples of the compound (A) containing an α,β-unsaturated double bond group include o-phenylphenyl (meth)acrylate, m-phenylphenyl (meth)acrylate, p-phenylphenyl (meth)acrylate, diphenylmethyl (meth)acrylate, 4-(1-methyl-1-phenylethyl) (meth)acrylate, triphenylmethyl (meth)acrylate, o-phenoxyphenyl (meth)acrylate, m-phenoxyphenyl (meth)acrylate, p-phenoxyphenyl (meth)acrylate, 9-(meth)acryloyloxyfluorene, 9-(meth)acryloyloxymethylfluorene, N-(meth)acryloylcarbazole, N-(meth)acryloylmethylcarbazole, and diphenylacrylamide. These may be used alone or in combination of two or more. Among these, from the viewpoint that the resin composition for photomodeling has low viscosity and the toughness of the cured product is excellent, preferred are o-phenylphenyl (meth)acrylate, m-phenylphenyl (meth)acrylate, p-phenylphenyl (meth)acrylate, diphenylmethyl (meth)acrylate, 4-(1-methyl-1-phenylethyl) (meth)acrylate, triphenylmethyl (meth)acrylate, 9-(meth)acryloyloxyfluorene, and 9-(meth)acryloyloxymethylfluorene; more preferred are p-phenylphenyl (meth)acrylate, diphenylmethyl (meth)acrylate, triphenylmethyl (meth)acrylate, 9-(meth)acryloyloxyfluorene, and 9-(meth)acryloyloxymethylfluorene; and further preferred are triphenylmethyl (meth)acrylate, 9-(meth)acryloyloxyfluorene, and 9-(meth)acryloyloxymethylfluorene.

[0051] The content of the compound (A) containing an α,β-unsaturated double bond group in the resin composition for photomodeling of the present invention is preferably 1.0 to 80% by mass in the total amount of the compound (A) containing an α,β-unsaturated double bond group, the compound (B) containing an α,β-unsaturated double bond group, the urethane (meth) acrylic compound (D) and other polymerizable compounds (hereinafter collectively referred to as "polymerizable compounds"). From the viewpoint of better modeling properties, toughness of the cured product and water resistance, it is more preferably 2.5 to 60% by mass, and further preferably 5 to 40% by mass.

[0052] [Compound (B) containing an α,β-unsaturated double bond group having a homopolymer glass transition temperature (Tg) of less than 40°C, a cyclic structure, and a normal pressure boiling point of 250°C or more]

[0053] The photomodeling resin composition of the present invention contains a compound (B) containing an α,β-unsaturated double bond group (hereinafter sometimes referred to as the compound (B) containing an α,β-unsaturated double bond group), the glass transition temperature (Tg) of the homopolymer of which is lower than 40°C, which has a cyclic structure and a normal pressure boiling point of 250°C or higher. The compound (B) containing an α,β-unsaturated double bond group is used in the photomodeling resin composition of the present invention to reduce the viscosity of the photomodeling resin composition, to impart excellent modeling properties, and to impart toughness and water resistance to the cured product.

[0054] The compound (B) containing an α,β-unsaturated double bond group in the present invention can suppress odor by making the atmospheric boiling point 250°C or more, and the resin composition for photomodeling of the present invention is less likely to feel unpleasant odor. The atmospheric boiling point of the compound (B) containing an α,β-unsaturated double bond group is preferably 275°C or more, more preferably 300°C or more. The atmospheric boiling point of the compound (B) containing an α,β-unsaturated double bond group is preferably 450°C or less, more preferably 400°C or less. It should be noted that the atmospheric boiling point in the present invention is a measured value obtained by atmospheric distillation. For compounds for which the atmospheric boiling point cannot be observed, the atmospheric boiling point converted from the reduced pressure boiling point as a measured value in the reduced pressure distillation using the boiling point conversion table (Science of Petroleum, Vol. II. p.1281 (1938)) is used.

[0055] The important thing about the compound (B) containing an α,β-unsaturated double bond group in the present invention is that the glass transition temperature (Tg) of the homopolymer is lower than 40°C. By making the glass transition temperature (Tg) of the homopolymer lower than 40°C, a structure with moderate flexibility is introduced, so that a three-dimensional shaped object with good toughness can be formed. The Tg of the homopolymer is preferably 35°C or lower.

[0056] The important thing about the compound (B) containing an α,β-unsaturated double bond group in the present invention is that it has a cyclic structure. By having a cyclic structure, the affinity with the compound (A) containing an α,β-unsaturated double bond group becomes higher, so the viscosity is reduced, and a resin composition for light shaping with excellent shaping properties is formed. As the cyclic structure, an aromatic ring, a heterocyclic ring (for example, a heterocyclic ring containing at least one atom selected from a nitrogen atom, an oxygen atom and a sulfur atom), an alicyclic ring, etc. can be cited, and an aromatic ring is preferred. The number of rings possessed by the compound (B) containing an α,β-unsaturated double bond group is not particularly limited, and is preferably 1 to 5, more preferably 1 to 4, and further preferably 2 to 3.

[0057] From the viewpoint of excellent toughness of the obtained cured product, the compound (B) containing an α,β-unsaturated double bond group in the present invention is preferably a monofunctional compound, more preferably a monofunctional (meth)acrylate compound (B)-1, and even more preferably a monofunctional (meth)acrylate compound having an aromatic ring.

[0058] Examples of the monofunctional (meth)acrylate compound (B)-1 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. 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)ethyl (meth)acrylate 4-(p-phenoxyphenyl)butyl (meth)acrylate, 4-(o-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, undecyl (meth)acrylate, Lauryl acrylate, tridecyl (meth)acrylate, tetradecyl (meth)acrylate, pentadecyl (meth)acrylate, cetyl (meth)acrylate, 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, erythritol mono(meth)acrylate, etc. The compound (B) containing an α,β-unsaturated double bond group may be used alone or in combination of two or more.Among these, those having an aromatic ring are preferred in terms of excellent curability of the photomodeling resin composition and toughness of the cured product. More preferred are 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. Further preferred are o-phenoxybenzyl acrylate, m-phenoxybenzyl acrylate, p-phenoxybenzyl acrylate, and ethoxylated-o-phenylphenol (meth)acrylate. Particularly preferred are o-phenoxybenzyl acrylate, m-phenoxybenzyl acrylate, and ethoxylated-o-phenylphenol (meth)acrylate. Most preferred are m-phenoxybenzyl acrylate and ethoxylated-o-phenylphenol (meth)acrylate.

[0059] The content of the compound (B) containing an α,β-unsaturated double bond group in the resin composition for photomodeling of the present invention is preferably 1 to 95% by mass in the total amount of the polymerizable compound, and is more preferably 5 to 90% by mass, and further preferably 10 to 80% by mass, from the viewpoint of better modeling properties, toughness of the cured product, and water resistance.

[0060] [Photopolymerization initiator (C)]

[0061] The photopolymerization initiator (C) 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.

[0062] As the photopolymerization initiator (C), there can be mentioned (bis)acylphosphine oxides, thioxanthones or quaternary ammonium salts of thioxanthones, acetals, α-diketones, coumarins, anthraquinones, benzoin alkyl ether compounds, α-aminoketone compounds, germanium compounds, etc. These can be used alone or in combination of two or more.

[0063] Among these photopolymerization initiators (C), at least one selected from (bis)acylphosphine oxides and α-diketones is preferably used. Thus, a photopolymerization resin composition having excellent photocurability in the ultraviolet region and the visible light region and showing sufficient photocurability even when using any light source selected from lasers, halogen lamps, light emitting diodes (LEDs) and xenon lamps is obtained.

[0064] 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. Further examples include compounds described in Japanese Patent Application Laid-Open No. 2000-159621.

[0065] 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 (C).

[0066] As α-diketones, for example, diacetyl, benzil, camphorquinone, 2,3-pentanedione, 2,3-octanedione, 9,10-phenanthrenequinone, 4,4'-oxybenzil, and acenaphthenequinone can be cited. Among these, camphorquinone is particularly preferred when a light source in the visible light region is used. As germanium compounds, for example, monoacyl germanium compounds such as benzoyltrimethylgermanium (IV); diacyl germanium compounds such as dibenzoyldiethylgermanium or bis(4-methoxybenzoyl)-diethylgermanium can be cited.

[0067] The content of the photopolymerization initiator (C) in the photomodeling resin composition of the present invention is not particularly limited as long as the effect of the present invention is achieved. From the viewpoint of the curability, toughness, water resistance, etc. of the obtained photomodeling resin composition, the photopolymerization initiator (C) is preferably 0.01 to 20 parts by mass relative to 100 parts by mass of the total amount of the polymerizable compound. When the content of the photopolymerization initiator (C) is less than 0.01 parts by mass, the polymerization cannot be fully carried out, and a three-dimensional modeling object may not be obtained. The content of the photopolymerization initiator (C) is more preferably 0.05 parts by mass or more, and further preferably 0.1 parts by mass or more, relative to the aforementioned total amount of 100 parts by mass. On the other hand, when the content of the photopolymerization initiator (C) is greater than 20 parts by mass, if the solubility of the photopolymerization initiator itself is low, it may cause precipitation from the photomodeling resin composition. The content of the photopolymerization initiator (C) 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.

[0068] [Urethaned (meth)acrylic acid compound (D)]

[0069] The resin composition for photomodeling of the present invention preferably further contains a urethanized (meth) acrylic compound (D) (except for the compound (B) containing an α,β-unsaturated double bond group). The urethanized (meth) acrylic compound (D) is used to impart curability to the resin composition for photomodeling of the present invention and to impart toughness to the cured product of the resin composition for photomodeling. The urethanized (meth) acrylic compound (D) may be used alone or in combination of two or more.

[0070] The urethanized (meth) acrylic compound (D) can be easily synthesized by, for example, subjecting a polyol containing a polymer skeleton described later, a compound having an isocyanate group (-NCO), and a (meth) acrylic ester compound having a hydroxyl group (-OH) to an addition reaction. In addition, the urethanized (meth) acrylic compound (D) can be easily synthesized by subjecting a (meth) acrylic compound having a hydroxyl group to a ring-opening addition reaction with a lactone or an alkylene oxide, and then subjecting the resulting compound having a hydroxyl group at a single terminal to an addition reaction with a compound having an isocyanate group.

[0071] The urethanized (meth)acrylic compound (D) is preferably a (meth)acrylate containing in one molecule a structure (polymer skeleton) of at least one selected from polyester, polycarbonate, polyurethane, polyether, polyconjugated diene and hydrogenated polyconjugated diene, and a urethane bond, and more preferably a (meth)acrylate having in the molecule a polyol moiety selected from at least one selected from polyester, polycarbonate, polyurethane, polyether, polyconjugated diene and hydrogenated polyconjugated diene having a structure derived from an aliphatic diol unit (d) having 4 to 18 carbon atoms and a branched structure, and a urethane bond. In the above structure, for example, as polyester, there can be mentioned 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 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, and preferably 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 the polycarbonate include polycarbonates 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 the polyurethane 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 the polyether include polyethylene glycol, polypropylene glycol, polybutylene glycol, poly(1-methylbutylene glycol), and the like. Examples of the polyconjugated diene and hydrogenated polyconjugated diene include 1,4-polybutadiene, 1,2-polybutadiene, polyisoprene, poly(butadiene-isoprene), poly(butadiene-styrene), poly(isoprene-styrene), polyfarnesene, and hydrogenated products thereof. Among these, a polyester structure is preferred in terms of excellent toughness.Furthermore, in terms of excellent water resistance and toughness, the structure of the polyester preferably contains a polyol portion and contains isophthalic acid ester or sebacate, wherein the polyol portion has a structure derived from an aliphatic diol unit (d) having 4 to 18 carbon atoms and a branched structure. In terms of excellent water resistance and styling properties, it is more preferred to contain a polyol portion and contains isophthalic acid ester or sebacate, wherein the polyol portion has a structure derived from an aliphatic diol unit (d) having 4 to 12 carbon atoms and a branched structure. It is further preferred to contain a polyol portion and contains isophthalic acid ester or sebacate, wherein the polyol portion has a structure derived from an aliphatic diol unit (d) having 5 to 12 carbon atoms and a branched structure. In the production of the urethanized (meth)acrylic compound (D), the aforementioned polyol having a polymer skeleton can be used.

[0072] 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).

[0073] Examples of the (meth)acrylic acid compound having a hydroxyl group include 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, N-hydroxyethyl (meth)acrylamide, N,N-bis(2-hydroxyethyl) (meth)acrylamide, and the like. Hydroxy (meth)acrylate compounds such as amide, 2-hydroxy-3-acryloxypropyl (meth)acrylate, 2,2-bis[4-[3-(meth)acryloxy-2-hydroxypropoxy]phenyl]propane, 1,2-bis[3-(meth)acryloxy-2-hydroxypropoxy]ethane, pentaerythritol tri(meth)acrylate, tri- or tetra(meth)acrylate of dipentaerythritol; hydroxy (meth)acrylamide compounds such as N-hydroxyethyl (meth)acrylamide and N,N-bis(2-hydroxyethyl) (meth)acrylamide, etc.

[0074] Examples of the aliphatic diol unit (d) 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, 2-methyl-1,11-decanediol, and 2-methyl-1,8-octanediol. Monodecanediol, 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 resin composition for photomodeling, it is preferred to use an aliphatic diol 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 as the polyol, more preferably 2-methyl-1,4-butanediol, 3-methyl-1,5-pentanediol, 2-methyl-1,8-octanediol, and 2,7-dimethyl-1,8-octanediol, and even more preferably 3-methyl-1,5-pentanediol and 2-methyl-1,8-octanediol.

[0075] The addition reaction of the compound having an isocyanate group and the (meth)acrylic compound having a hydroxyl group can be performed by a known method and is not particularly limited.

[0076] Examples of the urethanized (meth)acrylic compound (D) include a reaction product of any combination of the aforementioned polyol having at least one structure selected from 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.

[0077] From the viewpoint of viscosity and strength, the weight average molecular weight (Mw) of the urethanized (meth) acrylic compound (D) is preferably 1000 to 30000, more preferably 1500 to 15000, further preferably 2000 to 9000, further preferably 2000 to 8000, particularly preferably 2000 to 7000, and most preferably 2000 to 5000. In addition, the weight average molecular weight (Mw) in the present invention refers to the weight average molecular weight calculated by gel permeation chromatography (GPC) in terms of polystyrene.

[0078] The content of the urethanized (meth) acrylic compound (D) in the resin composition for photomodeling of the present invention is preferably 1 to 98% by mass in the total amount of the polymerizable compounds, more preferably 5 to 90% by mass, and further preferably 10 to 80% by mass from the viewpoint of better modeling properties, toughness including flexibility of the cured product, and water resistance.

[0079] The resin composition for photomodeling of the present invention may also contain other polymerizable compounds (hereinafter also referred to as "other polymerizable compounds") in addition to the compound (A) containing an α,β-unsaturated double bond group and the compound (B) containing an α,β-unsaturated double bond group, and the polymerizable compound may also be substantially composed of only the compound (A) containing an α,β-unsaturated double bond group and the compound (B) containing an α,β-unsaturated double bond group. That is, the resin composition for photomodeling of the present invention may also be substantially free of other polymerizable compounds (including urethanized (meth) acrylic compound (D)). In the present invention, the polymerizable compound is substantially composed of only a certain component, which means that the content of other polymerizable compounds other than the certain component 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 polymerizable compounds contained in the resin composition for photomodeling. As another suitable embodiment, in the resin composition for photomodeling of the present invention, the polymerizable compound may be substantially composed of a compound (A) containing an α,β-unsaturated double bond group, a compound (B) containing an α,β-unsaturated double bond group, and a urethanized (meth)acrylic compound (D). That is, the resin composition for photomodeling of the present invention may also be substantially free of other polymerizable compounds (except the urethanized (meth)acrylic compound (D)). As other polymerizable compounds (except the urethanized (meth)acrylic compound (D)), polyfunctional (meth)acrylate compounds, polyfunctional (meth)acrylamide compounds, and monofunctional (meth)acrylamide compounds having two or more polymerizable groups may be cited. As polyfunctional (meth)acrylate compounds, difunctional (meth)acrylate compounds of aromatic compound system, difunctional (meth)acrylate compounds of aliphatic compound system, trifunctional or higher (meth)acrylate compounds, etc. may be cited.

[0080] The photopolymerization resin composition of the present invention is not particularly limited as long as it contains the above-mentioned α,β-unsaturated double bond group-containing compound (A), α,β-unsaturated double bond group-containing compound (B) and photopolymerization initiator (C), and can be produced according to a known method.

[0081] The resin composition for photomodeling of the present invention may contain a polymerization accelerator to improve the photocurability within the scope of not damaging the main purpose of the present invention. As the polymerization accelerator, for example, 4-(N,N-dimethylamino) ethyl benzoate, 4-(N,N-dimethylamino) methyl benzoate, 4-(N,N-dimethylamino) benzoic acid n-butoxyethyl ester, 4-(N,N-dimethylamino) benzoic acid 2-(methacryloyloxy)ethyl ester, 4-(N,N-dimethylamino) benzophenone, 4-(N,N-dimethylamino) butyl benzoate and other amine compounds containing aromatic amines can be cited. Among these, from the viewpoint of imparting excellent curability to the resin composition for photomodeling, it is preferred to use at least one selected from 4-(N,N-dimethylamino) ethyl benzoate, 4-(N,N-dimethylamino) benzoic acid n-butoxyethyl ester and 4-(N,N-dimethylamino) benzophenone.

[0082] In the resin composition for photomodeling of the present invention, a filler may be further added in order to adjust the properties of the paste or to modify the surface properties or strength of the cured product of the resin composition for photomodeling. Examples of fillers include organic fillers, inorganic fillers, and organic-inorganic composite fillers. The filler may be used alone or in combination of two or more.

[0083] As the material of the organic filler, for example, 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, acrylonitrile-styrene-butadiene copolymer can be cited. One of them 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 also be appropriately selected and used. From the viewpoint of the operability and mechanical strength of the obtained light shaping resin composition, the average particle size of the aforementioned organic filler is preferably 0.001~50μm, more preferably 0.001~10μm, and further preferably 0.001~1.0μm.

[0084] As the material of the inorganic filler, for example, quartz, silica, alumina, silica-titania, silica-titania-barium oxide, silica-zirconium oxide, silica-alumina, lanthanum glass, borosilicate glass, sodium 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, strontium calcium fluoroaluminosilicate glass can be cited. They can also be used alone or in combination of two or more. The shape of the inorganic filler is not particularly limited, and irregular shape fillers or spherical fillers can be appropriately selected and used. From the viewpoints of the operability and mechanical strength of the obtained light shaping resin composition, the average particle size of the aforementioned inorganic filler is preferably 0.001~50μm, more preferably 0.001~10μm, and further preferably 0.001~1.0μm.

[0085] In order to adjust the fluidity of the resin composition for light shaping, the inorganic filler can be used after being surface-treated in advance with a known surface treatment agent such as a silane coupling agent as needed. Examples of the surface treatment agent include vinyl trimethoxysilane, vinyl triethoxysilane, vinyl trichlorosilane, vinyl tri(β-methoxyethoxy)silane, γ-methacryloxypropyl trimethoxysilane, 8-methacryloxyoctyl trimethoxysilane, 11-methacryloxy undecyl trimethoxysilane, γ-glycidoxypropyl trimethoxysilane, γ-mercaptopropyl trimethoxysilane, and γ-aminopropyl triethoxysilane.

[0086] The organic-inorganic composite filler used in the present invention refers to a substance 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 substance 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 0.001~50μm, more preferably 0.001~10μm, and further preferably 0.001~1.0μm.

[0087] It should be noted that in this specification, the average particle size of the filler refers to the average primary particle size, which can be obtained by laser diffraction scattering method or electron microscope observation of particles. Specifically, in the particle size measurement of particles above 0.1 μm, the laser diffraction scattering method is simple, and in the particle size measurement of ultrafine particles below 0.1 μm, electron microscope observation is simple. 0.1 μm is a value measured by laser diffraction scattering method.

[0088] Specifically, the laser diffraction scattering method can be measured by, 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.

[0089] Specifically, electron microscope observation can be obtained by, for example, taking an electron microscope (S-4000 type, manufactured by Hitachi, Ltd.) photograph of particles, and using image analysis type particle size distribution measurement software (Mac-View (manufactured by Mac-Tech, Ltd.)) to measure the particle diameter of the particles (more than 200) observed in the unit visual field of the photograph. At this time, the particle diameter is obtained as the arithmetic mean of the maximum length and the minimum length of the particles, and the average primary particle diameter is calculated by the number of particles and their particle diameter.

[0090] In the resin composition for light shaping of the present invention, a polymer may be added for modification of flexibility, fluidity, etc., within the scope of not damaging the main purpose of the present invention. 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 styrene elastomer may be added. As specific examples of other polymers that can be added, 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, etc. may be cited.

[0091] The resin composition for light shaping of the present invention may contain a softener as needed. As the softener, petroleum softeners such as paraffin, cycloalkane, and aromatic process oils can be cited; and plant oil softeners such as paraffin, peanut oil, and rosin can be cited. These softeners can be used alone or in combination of two or more. The content of the softener is not particularly limited as long as it does not damage the purpose of the present invention, and is usually 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.

[0092] The resin composition for photomodeling of the present invention may contain a chemical polymerization initiator to improve curability within the scope of not damaging the main purpose of the present invention. As chemical polymerization initiators, 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 substances can be used. Representative organic peroxides include ketone peroxides, hydroperoxides, diacyl peroxides, dialkyl peroxides, peroxy acetals, peroxy esters and peroxy dicarbonates. The chemical polymerization initiator can be used alone or in combination of two or more.

[0093] In addition, the resin composition for photomolding of the present invention may be formulated with a known stabilizer in order to inhibit degradation or adjust photocurability. Examples of the stabilizer include polymerization inhibitors, ultraviolet absorbers, and antioxidants. The stabilizer may be used alone or in combination of two or more.

[0094] Examples of the polymerization inhibitor include hydroquinone, hydroquinone monomethyl ether, dibutyl hydroquinone, dibutyl hydroquinone 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 relative to 100 parts by mass of the total amount of the polymerizable compound.

[0095] In addition, the resin composition for photomolding of the present invention may be formulated with known additives in order to adjust the color tone or adjust the paste properties. Examples of the aforementioned additives include pigments, dyes, organic solvents, and thickeners. The additives may be used alone or in combination of two or more.

[0096] The resin composition for photomodeling of the present invention is easy to shape when it is shaped by photomodeling (especially lift-type liquid tank photomodeling), and a shaped object with excellent toughness and water resistance can be obtained. In addition, it can also be applied to inkjet photomodeling. Therefore, the resin composition for photomodeling of the present invention and its cured product can be applied to uses that utilize such advantages (such as intraoral uses), and can be applied to dental materials or sleep disorder treatment materials. As a dental material, it is particularly suitable for dental treatment of dental braces (dental tooth pads, orthodontic appliances, braces, etc.) and denture base materials. Furthermore, in addition to dental treatment uses such as dental braces and denture base materials, the resin composition for photomodeling of the present invention can also be suitably used as a protective device and a mouthguard against external forces for sports. In addition, the resin composition for photomodeling of the present invention is more likely to obtain excellent toughness, water resistance, styling and other effects, so it is preferably used as a resin composition for lift-type liquid tank photomodeling. As a sleep disorder treatment material, it is particularly suitable for a therapeutic device for sleep apnea syndrome. The shape of the cured product using the resin composition for photomodeling of the present invention can be changed according to each use. In addition, the photomodeling resin composition of the present invention can adjust the types and contents of the components (compound (A) containing an α,β-unsaturated double bond group, compound (B) containing an α,β-unsaturated double bond group, photopolymerization initiator (C), urethanized (meth)acrylic compound (D) and various other components (polymerization accelerator, filler, polymer, softener, stabilizer, additive, etc.)) according to the needs for each application such as dental crowns and denture base materials.

[0097] The resin composition for photomolding of the present invention can be used for various purposes by utilizing its characteristics, especially the small volume shrinkage and excellent molding accuracy when cured by light, and the ability to obtain a three-dimensional molded object with excellent toughness and water resistance of the cured product, and further obtain other cured products. The resin composition for photomolding of the present invention can be used, for example, for the manufacture of three-dimensional molded objects using optical three-dimensional molding; dental materials; the manufacture of various molded products such as film-like objects or molds using cast molding, injection molding, etc.; molds for covering and vacuum molding, etc., and is particularly suitable for dental materials.

[0098] 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, while keeping the volume shrinkage rate during photocuring small, a three-dimensional molded object with excellent molding accuracy and excellent toughness and water resistance can be smoothly manufactured.

[0099] As another embodiment of the present invention, there can be mentioned a method of producing a three-dimensional object by an optical three-dimensional molding method using any of the above-mentioned resin compositions for optical molding.

[0100] When the optical stereoscopic shaping resin composition of the present invention is used for optical stereoscopic shaping (especially lift-up liquid tank optical shaping), the previously known lift-up optical stereoscopic shaping method and device (for example, optical shaping machines such as DIGITALWAX (registered trademark) 020D manufactured by DWS) can be used. The optical stereoscopic shaping method and device 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 a lift-up optical stereoscopic shaping device (lift-up liquid tank optical shaping device). Among them, in the present invention, as the light energy for curing the resin, active energy rays are preferably used. "Active energy rays" refer to energy rays such as ultraviolet rays, electron rays, X-rays, radiation, high frequencies, etc. that can cure the optical stereoscopic shaping resin composition. For example, the active energy rays can be ultraviolet rays having a wavelength of 300~420nm. As the light source of the active energy rays, lasers such as Ar lasers and He-Cd lasers can be cited; halogen lamps, xenon lamps, metal halide lamps, LEDs, mercury lamps, fluorescent lamps, etc., and lasers are particularly preferred. When using laser as a light source, the energy level can be increased and the molding time can be shortened. In addition, the good focusing property of laser light can be used to obtain a three-dimensional object with high molding accuracy.

[0101] As described above, when the optical stereoscopic molding resin composition of the present invention is used for optical stereoscopic molding, the conventionally known methods and conventionally known optical molding system devices can be used without special restrictions. As a representative example of the optical stereoscopic molding method preferably used in the present invention, a method of obtaining the final target stereoscopic molding object by repeatedly performing the following steps can be cited: the step of selectively irradiating the optical stereoscopic molding resin composition with active energy light in a manner to obtain a solidified layer having a desired pattern, thereby forming a solidified layer; and the step of further supplying an uncured liquid optical stereoscopic molding resin composition, similarly irradiating it with active energy light, and newly forming a solidified layer continuous with the aforementioned solidified layer, thereby laminating. In addition, the thus obtained stereoscopic molding object can be used directly, or, depending on the situation, it can also be further post-cured by light irradiation or post-cured by heat, etc., to further improve its mechanical strength or shape stability, etc. before use.

[0102] The flexural modulus of the cured product of the light shaping 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 further preferably in the range of 0.8 to 2.0 GPa. When the flexural modulus of the cured product is 2.0 GPa or less, a soft property is formed, and when it is made into a dental brace, it has good followability to the teeth, so it is excellent in wearing feeling, and it is not easy to fall off due to bruxism (grinding of teeth) during sleep at night. In addition, the flexural strength of the cured product of the light shaping resin composition of the present invention is preferably 30 MPa or more, more preferably 40 MPa or more, and further preferably 50 MPa or more.

[0103] The structure, shape, size, etc. of the three-dimensional object obtained by the optical three-dimensional modeling method are not particularly limited and can be determined according to various uses. Representative application fields of the optical three-dimensional modeling method of the present invention include models used to verify the appearance design during the design process; models used to check the functionality of parts; resin molds used to make castings; basic models used to make molds; direct molds for trial molds, etc. More specifically, models or processing models for precision parts, electrical and electronic parts, furniture, building structures, automotive parts, various containers, castings, molds, master molds, etc. can be cited. Example

[0104] Next, the present invention will be described in more detail with reference to Examples. However, the present invention is not limited to these Examples at all, and a person having ordinary knowledge in the art can make many modifications within the scope of the technical idea of ​​the present invention.

[0105] The components used in the photomodeling resin composition according to the examples and comparative examples are described below together with their abbreviations.

[0106] [Compound containing α,β-unsaturated double bond group (A)]

[0107] AFL: 9-acryloyloxyfluorene (manufactured by Chemsigma, white solid, homopolymer Tg: 100°C or higher)

[0108] TPMMA: triphenylmethyl methacrylate (manufactured by Carbon Science, Inc., white solid, Tg of homopolymer: 100°C or higher)

[0109] [Compound containing α,β-unsaturated double bond group (B)]

[0110] [Monofunctional (meth)acrylate compound (B)-1]

[0111] EPPA: Ethoxylated o-phenylphenol acrylate (manufactured by Shin-Nakamura Chemical Industry Co., Ltd., A-LEN-10, homopolymer Tg: 33°C, normal pressure equivalent boiling point: 300°C or higher)

[0112] POBA: m-Phenoxybenzyl methacrylate (manufactured by Kyoei Chemical Co., Ltd., colorless transparent liquid, homopolymer Tg: 35°C, normal pressure conversion boiling point: 300°C or more)

[0113] [Urethaned (meth)acrylic acid compound (D)]

[0114] The urethanized (meth)acrylic acid compounds (D)-1 and (D)-2 produced in Synthesis Examples 1 and 2 described later were used.

[0115] [Photopolymerization initiator (C)]

[0116] TPO: 2,4,6-Trimethylbenzoyldiphenylphosphine oxide

[0117] BAPO: Bis(2,4,6-trimethylbenzoyl)phenylphosphine oxide

[0118] [Polymerization inhibitor]

[0119] BHT: 3,5-di-tert-butyl-4-hydroxytoluene

[0120] <Synthesis Example 1> [Production of urethanized (meth)acrylic acid compound (D)-1]

[0121] (1) In 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 heated to 70° C. with stirring.

[0122] (2) On the other hand, 2500 g of polyester polyol ("Kuraray Polyol (registered trademark) P-2030" manufactured by Kuraray Co., Ltd.; a polyol formed from isophthalic acid and 3-methyl-1,5-pentanediol, with a weight average molecular weight (Mw) of 2000) was added to a dropping funnel with a side tube, and the liquid in the dropping funnel was dropped into the flask of (1) above. It should be noted that while the solution in the flask of (1) above was stirred, the internal temperature of the flask was maintained at 65 to 75°C, and the solution was dropped at a constant rate over 4 hours. Furthermore, after the dropwise addition was completed, the solution was stirred at the same temperature for 2 hours to react.

[0123] (3) Next, while the internal temperature of the flask was maintained at 55 to 65° C., a liquid obtained by uniformly dissolving 150 g of 2-hydroxyethyl acrylate and 0.4 g of hydroquinone monomethyl ether added to another dropping funnel was added dropwise at a constant speed over 2 hours, and then the temperature of the solution in the flask was maintained at 70 to 80° C. and reacted for 4 hours to obtain a carbamate-containing (meth)acrylic acid compound (D)-1. The weight average molecular weight (Mw) of the carbamate-containing (meth)acrylic acid compound (D)-1 analyzed by GPC was 2700.

[0124] <Synthesis Example 2> [Production of urethanized (meth)acrylic acid compound (D)-2]

[0125] (1) In 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 heated to 70° C. with stirring.

[0126] (2) On the other hand, 2500 g of polyester polyol ("Kuraray Polyol (registered trademark) P-2050" manufactured by Kuraray Co., Ltd.; a polyol formed from sebacic acid and 3-methyl-1,5-pentanediol, with a weight average molecular weight (Mw) of 2000) was added to a dropping funnel with a side tube, and the liquid in the dropping funnel was dropped into the flask of (1) above. It should be noted that while stirring the solution in the flask of (1) above, the internal temperature of the flask was maintained at 65 to 75°C, and the solution was dropped at a constant rate over 4 hours. Furthermore, after the dropwise addition was completed, the solution was stirred at the same temperature for 2 hours to react.

[0127] (3) Next, while the internal temperature of the flask was maintained at 55 to 65° C., a liquid obtained by uniformly dissolving 150 g of 2-hydroxyethyl acrylate and 0.4 g of hydroquinone monomethyl ether added to another dropping funnel was added dropwise at a constant speed over 2 hours, and then the temperature of the solution in the flask was maintained at 70 to 80° C. and reacted for 4 hours, thereby obtaining a carbamate-containing (meth)acrylic acid compound (D)-2. The weight average molecular weight (Mw) of the carbamate-containing (meth)acrylic acid compound (D)-2 analyzed by GPC was 2,600.

[0128] [Examples 1 to 6 and Comparative Examples 1 to 7]

[0129] The components shown in Tables 1 and 2 were mixed at room temperature (20°C ± 15°C, JIS (Japanese Industrial Standards) Z8703: 1983) to prepare pastes of the photomodeling resin compositions of Examples 1 to 6 and Comparative Examples 1 to 7.

[0130] <Styling>

[0131] For the light shaping resin composition involved in each embodiment and each comparative example, a light shaping machine (DIGITALWAX (registered trademark) 020D manufactured by DWS) was used to shape a test piece with a thickness of 3.3 mm × a width of 10.0 mm × a length of 64 mm (n=5). The case where a sheet with the required size can be shaped is recorded as "can be shaped"; the case where a three-dimensional shaped object cannot be obtained even in one attempt is recorded as "cannot be shaped" "×". It should be noted that the shaped test piece is used for the evaluations described later. The results of each evaluation are shown in Tables 1 and 2.

[0132] <Toughness (flexural modulus, flexural strength, fracture point displacement)>

[0133] For the cured product of the light shaping resin composition involved in each embodiment and each comparative example, a test piece (length 64.0 mm, width 10.0 mm, thickness 3.3 mm) of the size described in JIS T6501:2012 (acrylic resin for denture base) used in the evaluation of shaping properties was prepared. After being stored in the air for 1 day, a bending strength test was performed and evaluated, and it was recorded as the initial value. That is, a universal testing machine (manufactured by Shimadzu Corporation, Autograph AG-I 100kN) was used to implement a bending strength test (n=5) at a cross head speed of 5mm / min. The average value of the measured values ​​of each test piece was calculated and recorded as the bending strength and bending modulus. As the bending modulus of the test piece, it is preferably in the range of 0.3~3.0GPa, more preferably in the range of 0.5~2.5GPa, and further preferably in the range of 0.8~2.0GPa. As for 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 displacement of the breaking point, it is preferably not to break. If it does not break until the end or breaks at a displacement of more than 20 mm, it is recorded as good flexibility "○", if it breaks at a displacement of more than 10 mm and less than 20 mm, it is recorded as medium flexibility "△", and if it breaks at a displacement of less than 10 mm, it is recorded as poor flexibility "×".

[0134] <Water resistance>

[0135] For the cured products of the light shaping resin compositions involved in each embodiment and each comparative example, which were prepared in the same manner as the cured products prepared in the measurement of toughness, after being immersed in water at 37°C for 168 hours, the flexural strength was measured in the same manner as the above-mentioned flexural strength test (n=5). The measurement result of the flexural strength in the above-mentioned toughness is recorded as the initial flexural strength. If the rate of change (reduction rate) of the flexural strength after immersion in water at 37°C for 168 hours relative to the initial flexural strength is 10% or less, the water resistance is excellent, and if it is 7% or less, the water resistance is even better. In Tables 1 and 2, the flexural strength after immersion in water at 37°C for 168 hours is expressed as "flexural strength after immersion".

[0136] 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

[0137] <Odor>

[0138] For the light shaping resin composition involved in each embodiment and each comparative example, a panel of 10 people evaluated the odor (n=1). Among the 10 panelists, if less than 2 people felt the unpleasant odor, it was recorded as "○", if more than 2 people felt the unpleasant odor but less than 5 people felt the unpleasant odor, it was recorded as "△", and if more than 5 people felt the unpleasant odor, it was recorded as "×". As long as no unpleasant odor is felt, there is no special problem.

[0139]

[0140]

[0141] DCPA: dicyclopentenyl acrylate (manufactured by Hitachi Chemical Co., Ltd.; Tg of homopolymer: 120°C; boiling point at normal pressure: 252°C)

[0142] ACMO: N-acryloylmorpholine (manufactured by KJ Chemicals Co., Ltd.; Tg of homopolymer: 145°C; boiling point at normal pressure: 255°C)

[0143] AMM: 9-Anthracenylmethyl methacrylate (manufactured by Tokyo Chemical Industry Co., Ltd.; Tg of homopolymer: 100°C or higher, boiling point at normal pressure: 300°C or higher)

[0144] IBA: Isobornyl acrylate (manufactured by Tokyo Chemical Industry Co., Ltd., homopolymer Tg: 94-97°C, normal pressure equivalent boiling point: 245°C)

[0145] As shown in Tables 1 and 2, the photomodeling resin compositions of Examples 1 to 6 have excellent modeling properties, low odor, and excellent toughness and water resistance of their cured products. In particular, the toughness and water resistance of the cured products of the photomodeling resin compositions of Examples 1 to 6 are superior to the cured products of the resin compositions of Comparative Examples 3 to 5 that do not contain the α,β-unsaturated double bond group-containing compound (A) and the α,β-unsaturated double bond group-containing compound (B) of the present invention, and the cured products of the resin compositions of Comparative Examples 1 and 7 that do not contain the α,β-unsaturated double bond group-containing compound (A) of the present invention. The photomodeling resin composition of Comparative Example 2 that does not contain the α,β-unsaturated double bond group-containing compound (A) and the α,β-unsaturated double bond group-containing compound (B) has poor modeling properties, and a test piece cannot be formed, and various properties cannot be measured. The resin composition of Comparative Example 6 containing a condensed ring compound cannot be uniformly dissolved. In addition, the resin composition of Comparative Example 6 produces an unpleasant odor.

[0146] Industrial Applicability

[0147] The resin composition for photomolding of the present invention is easy to shape, has low odor, and can obtain a molded object with excellent toughness and water resistance when being molded by photomolding. Therefore, its cured product is suitable for dental materials (especially dental braces and denture base materials) and sleep disorder treatment materials (especially treatment devices for sleep apnea syndrome).

Claims

1. A resin composition for photomodeling, comprising: a compound (A) containing an α,β-unsaturated double bond group, the homopolymer of which has a glass transition temperature Tg of 40°C or higher, has multiple independent aromatic rings, and has no urethane bond; a compound (B) containing an α,β-unsaturated double bond group, the homopolymer of which has a glass transition temperature Tg of less than 40°C, has a cyclic structure, and has a normal pressure boiling point of 250°C or higher; a photopolymerization initiator (C); and a urethanized (meth)acrylic compound (D), wherein the urethanized (meth)acrylic compound (D) does not include the substance belonging to the aforementioned compound (B) containing an α,β-unsaturated double bond group. The content of the compound (A) containing an α,β-unsaturated double bond group is 1.0 to 80% by mass in the total amount of the compound (A) containing an α,β-unsaturated double bond group, the compound (B) containing an α,β-unsaturated double bond group, the urethanized (meth)acrylic compound (D) and other polymerizable compounds. The content of the compound (B) containing an α,β-unsaturated double bond group is 10 to 80% by mass in the total amount of the compound (A) containing an α,β-unsaturated double bond group, the compound (B) containing an α,β-unsaturated double bond group, the urethanized (meth)acrylic compound (D) and other polymerizable compounds. The urethanized (meth)acrylic compound (D) accounts for 10 to 80% by mass of the total amount of the α,β-unsaturated double bond group-containing compound (A), the α,β-unsaturated double bond group-containing compound (B), the urethanized (meth)acrylic compound (D) and other polymerizable compounds. The aforementioned compound (A) containing an α,β-unsaturated double bond group is a monofunctional (meth)acrylate compound (A)-1, The aforementioned multiple independent aromatic rings refer to a fused ring compound that does not include a skeleton in which two or more aromatic rings are directly fused to each other. The urethanized (meth)acrylic compound (D) 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.

2. The resin composition for photomodeling according to claim 1, wherein The aforementioned multiple independent aromatic rings are a biphenyl skeleton, a diphenylmethyl skeleton, a 2,2-diphenylpropane skeleton, a triphenylmethyl skeleton, a diphenylether skeleton, a fluorene skeleton or a diphenylamine skeleton.

3. The resin composition for photomolding according to claim 1 or 2, wherein: The aforementioned multiple independent aromatic rings are a triphenylmethyl skeleton or a fluorene skeleton.

4. The resin composition for photomolding according to claim 1 or 2, wherein: The aforementioned α,β-unsaturated double bond group-containing compound (A) is at least one selected from the group consisting of triphenylmethyl (meth)acrylate, 9-(meth)acryloyloxyfluorene, and 9-(meth)acryloyloxymethylfluorene.

5. The resin composition for photomodeling according to claim 1 or 2, wherein: The aforementioned α,β-unsaturated double bond group-containing compound (B) is a monofunctional compound.

6. The resin composition for photomolding according to claim 1 or 2, wherein: The aforementioned α,β-unsaturated double bond group-containing compound (B) is a monofunctional (meth)acrylate compound (B)-1.

7. The resin composition for photomolding according to claim 1 or 2, wherein: The aforementioned ring structure is an aromatic ring.

8. The resin composition for photomodeling according to claim 1 or 2, wherein: The aforementioned compound (B) containing an α,β-unsaturated double bond group is at least one selected from 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.

9. The resin composition for photomolding according to claim 1 or 2, wherein: The urethanized (meth)acrylic compound (D) is a (meth)acrylic acid ester containing a polyol moiety 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 an aliphatic diol unit (d) having 4 to 18 carbon atoms and having a branched structure. 10 . A dental material comprising a cured product of the photomodeling resin composition according to claim 1 .

11. A dental mouthpiece comprising a cured product of the photomodeling resin composition according to any one of claims 1 to 9.

12. A denture base material comprising a cured product of the photomodeling resin composition according to any one of claims 1 to 9. 13 . A material for treating sleep disorders, comprising a cured product of the resin composition for photomodeling according to claim 1 .

14. 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 9.

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