Photocurable Resin Composition for Orthodontic Appliances

Abstract

The present invention provides a photosetting orthodontic appliance resin composition that has excellent paste characteristics and that is suitable for an orthodontic appliance, in particular, for an aligner-correction dental attachment and an orthodontic bracket adhesive. The present invention pertains to a photosetting orthodontic appliance resin composition that contains a polymerizable monomer (A), a photoinitiator (B), and a filler (C), and that has a viscosity of 1-1000 Pa·s as measured at a shear rate of 10 s-1 at 25°C by using a rotation type viscoelasticity measuring apparatus, and a shear viscosity ratio (ηr) represented by formula (1) of 10 or higher.

Description

[Technical Field]

[0001] This invention relates to a resin composition for orthodontic appliances. [Background technology]

[0002] Traditionally, the bracket method has been the mainstream for orthodontic treatment. However, in recent years, due to the unnatural appearance of brackets, orthodontic treatment using colorless, transparent mouthpieces called orthodontic aligners (hereinafter sometimes simply referred to as "aligners") has become increasingly popular. In bracket treatment, brackets, which have a shape for attaching wires, are attached to the tooth surface, and by attaching wires to these brackets, a mechanical load (hereinafter sometimes referred to as "orthodontic force") is applied to guide the teeth into the desired position. In bracket treatment, orthodontic adhesive is generally used to attach the brackets to the tooth surface. On the other hand, in aligner treatment, aligners, which have a mouthpiece shape, are worn. In this case as well, a method has been developed in which protrusions called attachments are formed on the tooth surface, and by hooking the aligner onto these protrusions, a more appropriate mechanical load is applied, and the teeth are guided into the desired position more efficiently. These orthodontic adhesives and attachments generally use dental materials consisting of a curable composition containing polymerizable monomers such as (meth)acrylic acid esters, polymerization initiators, and fillers, with dental composite resin being commonly used.

[0003] Attachments are formed using a template, which is a mouthpiece that reflects the position of the teeth before orthodontic treatment. The following describes a general method of attachment formation using a template. The template has a recess with the shape of the attachment at a position corresponding to the tooth surface, and dental composite resin is first filled into this recess. The area on the tooth surface where the attachment will be formed is selectively surface-treated (etched) with phosphoric acid or the like beforehand, and then orthodontic adhesive is applied to that area. If necessary, the solvent is removed by air blowing and the orthodontic adhesive is cured by light irradiation or the like. After the template filled with dental material is placed on the teeth, the dental material filled in the recess with the shape of the attachment is cured by light irradiation or the like, thereby forming an attachment at the desired position on the tooth surface. When the template with the dental composite resin filled into the recess is placed on the teeth and the dental composite resin is pressed against the tooth surface, it needs to have enough fluidity to spread out. Furthermore, in orthodontic treatment using aligners, accurate fixation of attachments on the tooth surface is crucial for the aligners to exert sufficient orthodontic force when worn. If the attachments are not fixed in the correct and secure position, they may fall off during orthodontic treatment, or the teeth may not be moved as planned. Therefore, when a template with dental composite resin filled in the aforementioned recesses is placed on the dentition and the dental composite resin is pressed against the tooth surface, it must have sufficient fluidity to spread, while also possessing moldability to prevent the attachments from moving until they harden and become fixed after their position has been determined. Thus, both fluidity and moldability are required.

[0004] Furthermore, in bracket bonding, orthodontic adhesive is applied to the tooth surface side of the bracket, pressed against the tooth surface, its position is adjusted, and the bracket is fixed in place by curing the orthodontic adhesive with light irradiation or the like. The orthodontic adhesive used in the bracket bonding procedure must be easily applied to the bracket, have sufficient fluidity to spread when pressed against the tooth surface, and also have moldability to prevent the bracket from moving after its position is determined. Similar to attachments, it needs to have excellent operability with appropriate moldability and fluidity.

[0005] Traditionally, chemically curing dental materials were used for forming attachments and bonding brackets. However, light-curing materials, which can be cured at the desired time, are easier to handle because no mixing is required, and produce less material waste, are becoming increasingly popular.

[0006] The following technologies are known regarding such orthodontic adhesives. Patent Document 1 describes an example of a photocurable orthodontic adhesive that contains a filler having a specific Vickers hardness and has excellent properties for removing excess adhesive and cured material. Patent Document 2 describes an example of a photocurable orthodontic adhesive that contains hydrophobized fumed silica and a filler with a specific particle size and shape and has excellent operability and cured material removal properties. Patent Document 3 describes an example of a photocurable adhesive that contains a monomer with a specific amount of alkylene chains and is suitable for flexible and tough orthodontic brackets. Furthermore, Patent Document 4 reports an example of a photocurable adhesive that contains flexible crosslinked polyurethane and is suitable for flexible and tough orthodontic brackets. [Prior art documents] [Patent Documents]

[0007] [Patent Document 1] International Publication No. 2015 / 141683 [Patent Document 2] Japanese Patent Publication No. 2010-46266 [Patent Document 3] Japanese Patent Publication No. 2011-207806 [Patent Document 4] Japanese Patent Publication No. 2016-6040 [Overview of the Initiative] [Problems that the invention aims to solve]

[0008] The orthodontic adhesives described in Patent Documents 1 and 2 describe the ease of removal of excess adhesive using the indicator of stringiness, but there is no description regarding fluidity and moldability. The dental curing compositions described in Patent Documents 3 and 4 have a low elastic modulus and are particularly suitable as materials for fixing mobile teeth, but they are too soft to be used as adhesives for attachments and orthodontic brackets. In other words, there was room for improvement in terms of achieving an appropriate paste consistency.

[0009] Therefore, the present invention aims to provide a light-curable resin composition for orthodontic appliances that has excellent paste properties and is suitable for use as an adhesive for dental attachments and orthodontic brackets, particularly for orthodontic appliances such as aligners. [Means for solving the problem]

[0010] In other words, the present invention encompasses the following inventions. [1] Containing a polymerizable monomer (A), a photopolymerization initiator (B), and a filler (C), Using a rotary viscoelasticity measuring device, at 25°C and a shear rate of 10s, -1 The viscosity measured is 1 to 1000 Pa·s, and the shear viscosity ratio (η) is expressed by the following formula (1). r A photocurable resin composition for orthodontic appliances having a ratio of 10 or more;

number

[10] A photocurable resin composition for orthodontic appliances according to any one of [3] to [9], wherein the hydrophobic polymerizable monomer (A-2b) that does not have an acidic group comprises a hydrophobic polymerizable monomer having a hydroxyl group;

[11] A photocurable resin composition for orthodontic appliances according to any one of [1] to

[10] , wherein the photopolymerization initiator (B) comprises a water-soluble photopolymerization initiator (B-1);

[12] The photocurable resin composition for orthodontic appliances according to any one of [1] to

[11] , wherein the photopolymerization initiator (B) comprises a water-insoluble photopolymerization initiator (B-2);

[13] The photocurable resin composition for orthodontic appliances according to any one of [1] to

[12] , wherein the cured product of the photocurable resin composition for orthodontic appliances has a flexural strength of 60 MPa or more and less than 145 MPa;

[14] The photocurable resin composition for orthodontic appliances according to any one of [1] to

[13] , wherein the compressive strength of the cured product of the photocurable resin composition for orthodontic appliances is 250 to 400 MPa;

[15] The photocurable resin composition for orthodontic appliances according to any one of [1] to

[14] , wherein the photocurable resin composition for orthodontic appliances is a single-component type; Orthodontic attachments comprising a cured product of a photocurable resin composition for orthodontic appliances described in any of

[16] [1] to

[15] ; An adhesive for orthodontic brackets comprising a photocurable resin composition for orthodontic appliances as described in any of

[17] [1] to

[15] . [Effects of the Invention]

[0011] According to the present invention, a photocurable resin composition for orthodontic appliances is provided that has excellent paste properties and is suitable for orthodontic appliances, particularly dental attachments for aligner orthodontics and adhesives for orthodontic brackets. The photocurable resin composition for orthodontic appliances of the present invention has excellent paste properties that balance fluidity and moldability. [Brief explanation of the drawing]

[0012] [Figure 1] Figure 1 is a schematic diagram of a dental attachment relating to one embodiment of the present invention. [Modes for carrying out the invention]

[0013] The photocurable resin composition for orthodontic appliances of the present invention contains a polymerizable monomer (A), a photopolymerization initiator (B), and a filler (C), and was measured using a rotational viscoelasticity measuring device at 25°C and a shear rate of 10s. -1 The viscosity measured is 1 to 1000 Pa·s, and the shear viscosity ratio (η) is expressed by the following formula (1). r The ratio is 10 or more. Furthermore, the photocurable resin composition for orthodontic appliances of the present invention is in paste form.

number

[0014] The photocurable resin composition for orthodontic appliances of the present invention, from the viewpoint of paste properties, is suitable for use at 25°C and a shear rate of 10s. -1The viscosity measured must be between 1 and 1000 Pa·s, preferably between 10 and 750 Pa·s, more preferably between 15 and 700 Pa·s, and even more preferably between 20 and 500 Pa·s. If the viscosity is less than 1 Pa·s, the composition will drip when bonding dental attachments or brackets, making it impossible to fix the dental attachments or brackets in the correct position. If the viscosity exceeds 1000 Pa·s, the fluidity will be insufficient, the composition will not spread, and the layer of the composition will become too thick, resulting in excessively high flexural strength of the cured product or requiring a large force to spread the paste when positioning the dental attachments or brackets. The viscosity can be measured using a known rotary viscoelasticity measuring device. Examples of known rotary viscoelasticity measuring devices include "ARES-G2" (rotary rheometer, manufactured by TA Instruments Co., Ltd.). For compositions with high viscosity, such as those in the present invention, a flat parallel plate is preferred as the plate used for measurement. In this specification, "dental attachment" means an orthodontic attachment, that is, an orthodontic component used with an orthodontic aligner. Figure 1 shows a schematic diagram of a "dental attachment". For example, as shown in Figure 1, the dental attachment 1 is formed as a projection on the surface of a tooth 2, including an uncut natural tooth, and by hooking the orthodontic aligner onto the projection, a more appropriate mechanical load can be applied, allowing the teeth to be guided to the desired position more efficiently.

[0015] Next, the shear viscosity ratio (η) expressed by equation (1) r This explains the following. In equation (1), "25°C, shear rate 10s" -1 The viscosity measured at 25°C with a shear rate of 0.001 s² is the viscosity assumed for clinical operations where a relatively large shear force is applied to the resin composition (paste), such as when using the photocurable orthodontic resin composition of the present invention (for example, when applying or filling). A relatively small viscosity value means that the paste has high fluidity. Therefore, it is judged that the photocurable orthodontic resin composition has high operability in the clinical operation when applying or filling. On the other hand, at 25°C with a shear rate of 0.001 s², the viscosity is measured at 25°C with a shear rate of 0.001 s².-1 The viscosity measured is the viscosity assumed for clinical operations (operations up to polymerization and hardening) where relatively little shear force is applied after applying or filling the photocurable orthodontic resin composition and then attaching a template for forming dental attachments or determining the position of brackets. A higher value indicates that the paste does not flow. Therefore, it is judged that the viscosity is highly manageable in the clinical operations from the application or filling of the photocurable orthodontic resin composition until it hardens and is fixed. The viscosity can be measured using a known rotary viscoelasticity measuring device. Examples of known rotary viscoelasticity measuring devices include "ARES-G2" (rotary rheometer, manufactured by TA Instruments Co., Ltd.).

[0016] From the above, the shear viscosity ratio (η r The larger the value of (η), the more suitable the paste properties are for the shear force applied to the paste during clinical use, and the better the operability in clinical operations related to the formation of dental attachments for aligner orthodontics and the bonding of brackets. r The shear viscosity ratio (η) must be 10 or more, preferably 100 or more, and more preferably 200 or more. In one embodiment, the shear viscosity ratio (η) r Examples include a photocurable resin composition for orthodontic appliances having a shear viscosity ratio (η) of 20 or more. Another embodiment is the shear viscosity ratio (η) r Examples include photocurable resin compositions for orthodontic appliances having a shear viscosity ratio (η) of 35 or more. r The upper limit of the shear viscosity ratio (η) is not limited, but for example it can be 10,000 or less, 5,000 or less, 3,000 or less, or 2,000 or less. rIf the shear viscosity ratio is less than 10, the operability required for clinical operations related to the formation of dental attachments for aligner orthodontics and the bonding of brackets cannot be obtained. In order to increase the shear viscosity ratio of the photocurable resin composition for orthodontic appliances, it is important that the polymerizable monomers, photopolymerization initiators, and fillers contained therein form a network with reversible and relatively weak bonds such as weak ionic bonds, intermolecular interactions, interparticle interactions, hydrophobic interactions, solvation effects, and entanglement of molecular chains, rather than irreversible and strong bonds such as covalent bonds, and that the composition has thixotropy. The shear viscosity ratio can be adjusted, for example, by selectively combining a polymerizable monomer (A) and a filler (C). An example of a method for adjusting the shear viscosity ratio is to blend a polymerizable monomer (A), a filler (C-1) with an average particle diameter of 1 nm or more and less than 0.1 μm, and a filler (C-2) with an average particle diameter of 0.1 μm or more and 1 μm or less in a specific ratio. Depending on the combination of each component (type and content), the shear viscosity ratio (η r The shear viscosity ratio (η) can be adjusted to 10 or more. r The measurement method for ) will be described in detail in the examples below.

[0017] The cured product of the photocurable resin composition for orthodontic appliances of the present invention preferably has a compressive strength of 250 to 400 MPa, more preferably 260 to 375 MPa, and even more preferably 270 to 350 MPa, from the viewpoint of the strength and removeability of the dental attachment or bracket. Having a compressive strength within the above specific range means that the cured product has appropriate strength and brittleness, and tends to have excellent strength and removeability of the dental attachment or bracket. The method for measuring compressive strength in the present invention will be described in detail in the examples below.

[0018] The cured product of the photocurable resin composition for orthodontic appliances of the present invention preferably has a three-point bending strength of 40 MPa or more and less than 145 MPa, more preferably 60 MPa or more and 140 MPa or less, and even more preferably 70 MPa or more and 140 MPa or less, from the viewpoint of preventing detachment of dental attachments and brackets and ease of removal. If the three-point bending strength is less than 40 MPa, the dental attachment or bracket tends to detach easily due to wear or breakage, and if it is 145 MPa or more, the dental attachment or bracket tends to be difficult to remove. The method for measuring the three-point bending strength of the cured product is as described in the examples below.

[0019] Furthermore, it is essential that dental attachments and brackets do not fall off during orthodontic treatment. On the other hand, since they are removed when orthodontic treatment is completed, discontinued, or changed, they also need to be easily removable when no longer needed. The common method of removal is to use a pliers-shaped dental remover, but since removal is done by peeling or crushing and destroying, a certain degree of adhesion or strength is sometimes required. However, if the material is too brittle, it becomes difficult to apply orthodontic force effectively, and there is a problem of it breaking during orthodontic treatment. If the strength is too high, there is a problem of it being difficult to remove. Therefore, a certain hardness and strength that is not too soft, and an appropriate strength are also required. From the viewpoint of orthodontic efficiency and removeability, the cured product of the photocurable resin composition for orthodontic appliances of the present invention preferably has a flexural modulus of 2.0 to 12.0 GPa, more preferably 2.5 to 10.0 GPa, and even more preferably 3.0 to 9.0 GPa. If the flexural modulus is less than 2.0 GPa, it tends to be too flexible, making it difficult to effectively apply orthodontic force to dental attachments or brackets. If it exceeds 12.0 GPa, it tends to be too hard, making it difficult to remove dental attachments or brackets. The method for measuring the flexural modulus of the hardened material is as described in the examples below.

[0020] Polymerizable monomer (A) In the photocurable resin composition for orthodontic appliances of the present invention, a radical polymerizable monomer is preferably used as the polymerizable monomer (A). Specific examples of radical polymerizable monomers in polymerizable monomer (A) include (meth)acrylate polymerizable monomers, (meth)acrylamide polymerizable monomers, esters such as α-cyanoacrylic acid, (meth)acrylic acid, α-halogenated acrylic acid, crotonic acid, cinnamic acid, sorbic acid, maleic acid, and itaconic acid, vinyl esters, vinyl ethers, mono-N-vinyl derivatives, and styrene derivatives. From the viewpoint of curability, (meth)acrylate polymerizable monomers and (meth)acrylamide polymerizable monomers are preferred as polymerizable monomer (A). Furthermore, from the viewpoint of adhesion to tooth structure, brittleness, and elastic modulus, it is preferable that polymerizable monomer (A) contains a polymerizable monomer (A-1) having an acidic group and a polymerizable monomer (A-2) not having an acidic group. Other preferred embodiments include a photocurable resin composition for orthodontic appliances in which polymerizable monomer (A) does not contain polymerizable monomer (A-1) having an acidic group, but contains polymerizable monomer (A-2) that does not have an acidic group.

[0021] • Polymerizable monomer having an acidic group (A-1) The photocurable resin composition for orthodontic appliances of the present invention contains a polymerizable monomer (A-1) having an acidic group, and when combined with viscosity ratios and other factors, it not only has excellent paste properties but also superior adhesion to uncut enamel, allowing for precise fixation of dental attachments or brackets on the tooth surface as an adhesive for dental attachments and orthodontic brackets. Examples of the polymerizable monomer (A-1) having an acidic group used in the present invention include (meth)acrylic acid esters having at least one acidic group such as a phosphate group, pyrophosphate group, thiophosphate group, phosphonic acid group, carboxylic acid group, or sulfonic acid group. The polymerizable monomer (A-1) having an acidic group can be used alone or in appropriate combinations of two or more types. Specific examples of polymerizable monomers (A-1) having an acidic group are given below.

[0022] Examples of polymerizable (meth)acrylate monomers having a phosphate group include 2-(meth)acryloyloxyethyl dihydrogen phosphate, 3-(meth)acryloyloxypropyl dihydrogen phosphate, 4-(meth)acryloyloxybutyl dihydrogen phosphate, 5-(meth)acryloyloxypentyl dihydrogen phosphate, 6-(meth)acryloyloxyhexyl dihydrogen phosphate, 7-(meth)acryloyloxyheptyl dihydrogen phosphate, 8-(meth)acryloyloxyoctyl dihydrogen phosphate, 9-(meth)acryloyloxynonyl dihydrogen phosphate, 10-(meth)acryloyloxydecyl dihydrogen phosphate, 11-(meth)acryloyloxyundecyl dihydrogen phosphate, 12-(meth)acryloyloxidedecyl dihydrogen phosphate, 16-(meth)acryloyloxyhexadecyl dihydrogen phosphate, 20-(meth)acryloyloxyicosyldihydrogen phosphate Hydrogen phosphate, bis[2-(meth)acryloyloxyethyl]hydrogen phosphate, bis[4-(meth)acryloyloxybutyl]hydrogen phosphate, bis[6-(meth)acryloyloxyhexyl]hydrogen phosphate, bis[8-(meth)acryloyloxyoctyl]hydrogen phosphate, bis[9-(meth)acryloyloxynonyl]hydrogen phosphate, bis[10-(meth)acryloyloxydecyl]hydrogen phosphate, Examples include 1,3-di(meth)acryloyloxypropyl dihydrogen phosphate, 2-(meth)acryloyloxyethylphenyl hydrogen phosphate, 2-(meth)acryloyloxyethyl-(2-bromoethyl) hydrogen phosphate, 2-methacryloyloxyethyl-(4-methoxyphenyl) hydrogen phosphate, 2-methacryloyloxypropyl-(4-methoxyphenyl) hydrogen phosphate, and their acid chlorides, alkali metal salts, and amine salts.

[0023] Examples of (meth)acrylate polymerizable monomers having a pyrophosphate group include bis[2-(meth)acryloyloxyethyl] pyrophosphate, bis[4-(meth)acryloyloxybutyl] pyrophosphate, bis[6-(meth)acryloyloxyhexyl] pyrophosphate, bis[8-(meth)acryloyloxyoctyl] pyrophosphate, bis[10-(meth)acryloyloxydecyl] pyrophosphate, and their acid chlorides, alkali metal salts, and amine salts.

[0024] Examples of polymerizable (meth)acrylate monomers having a thiophosphate group include 2-(meth)acryloyloxyethyl dihydrogenthiophosphate, 3-(meth)acryloyloxypropyl dihydrogenthiophosphate, 4-(meth)acryloyloxybutyl dihydrogenthiophosphate, 5-(meth)acryloyloxypentyl dihydrogenthiophosphate, 6-(meth)acryloyloxyhexyl dihydrogenthiophosphate, 7-(meth)acryloyloxyheptyl dihydrogenthiophosphate, and 8-(meth)acryloyloxyoctyl dihydrogenthiophosphate. Examples include hydroxythiophosphates, 9-(meth)acryloyloxynonyldihydrogenthiophosphate, 10-(meth)acryloyloxydecyldihydrogenthiophosphate, 11-(meth)acryloyloxyundecyldihydrogenthiophosphate, 12-(meth)acryloyloxidedecyldihydrogenthiophosphate, 16-(meth)acryloyloxyhexadecyldihydrogenthiophosphate, 20-(meth)acryloyloxyicosyldihydrogenthiophosphate, and their acid chlorides, alkali metal salts, and ammonium salts.

[0025] Examples of polymerizable (meth)acrylate monomers having a phosphonic acid group include 2-(meth)acryloyloxyethylphenylphosphonate, 5-(meth)acryloyloxypentyl-3-phosphonopropionate, 6-(meth)acryloyloxyhexyl-3-phosphonopropionate, 10-(meth)acryloyloxydecyl-3-phosphonopropionate, 6-(meth)acryloyloxyhexyl-3-phosphonoacetate, 10-(meth)acryloyloxydecyl-3-phosphonoacetate, and their acid chlorides, alkali metal salts, and ammonium salts.

[0026] Examples of (meth)acrylate polymerizable monomers having a carboxylic acid group include monofunctional polymerizable monomers having one carboxyl group or its acid anhydride group in the molecule, and monofunctional polymerizable monomers having multiple carboxyl groups or their acid anhydride groups in the molecule.

[0027] Examples of monofunctional (meth)acrylate polymerizable monomers having one carboxyl group or acid anhydride group in the molecule include (meth)acrylic acid, N-(meth)acryloylglycine, N-(meth)acryloylaspartic acid, 2-(meth)acryloyloxyethyl hydrogen succinate, 2-(meth)acryloyloxyethyl hydrogen phthalate, 2-(meth)acryloyloxyethyl hydrogen malate, O-(meth)acryloyltyrosine, N-(meth)acryloyl Examples include liloyl tyrosine, N-(meth)acryloylphenylalanine, N-(meth)acryloyl-p-aminobenzoic acid, N-(meth)acryloyl-o-aminobenzoic acid, 2-(meth)acryloyloxybenzoic acid, 3-(meth)acryloyloxybenzoic acid, 4-(meth)acryloyloxybenzoic acid, N-(meth)acryloyl-5-aminosalicylic acid, N-(meth)acryloyl-4-aminosalicylic acid, and compounds in which the carboxyl group of these compounds has been replaced with an acid anhydride group.

[0028] Examples of monofunctional (meth)acrylate polymerizable monomers having multiple carboxyl groups or acid anhydride groups in the molecule include, for example, 6-(meth)acryloyloxyhexane-1,1-dicarboxylic acid, 9-(meth)acryloyloxynonane-1,1-dicarboxylic acid, 10-(meth)acryloyloxydecane-1,1-dicarboxylic acid, 11-(meth)acryloyloxyundecane-1,1-dicarboxylic acid, 12-(meth)acryloyloxidedecane-1,1-dicarboxylic acid, 13-(meth)acryloyloxytridecane-1,1-dicarboxylic acid, 4-(meth)acryloyloxyethyl trimellitate, 4-(meth)acryloyloxyethyl trimellitate anhydride, 4-(meth) Examples include acryloyloxybutyl trimellitate, 4-(meth)acryloyloxyhexyl trimellitate, 4-(meth)acryloyloxydecyl trimellitate, 2-(meth)acryloyloxyethyl-3'-(meth)acryloyloxy-2'-(3,4-dicarboxybenzoyloxy)propyl succinate, 6-(meth)acryloyloxyethylnaphthalene-1,2,6-tricarboxylic acid anhydride, 6-(meth)acryloyloxyethylnaphthalene-2,3,6-tricarboxylic acid anhydride, 4-(meth)acryloyloxyethyl carbonylpropionoyl-1,8-naphthalic acid anhydride, and 4-(meth)acryloyloxyethylnaphthalene-1,8-tricarboxylic acid anhydride.

[0029] An example of a polymerizable (meth)acrylate monomer having a sulfonic acid group is 2-sulfoethyl (meth)acrylate.

[0030] Among the polymerizable monomers (A-1) having acidic groups as described above, it is preferable that the composition contains a (meth)acrylate polymerizable monomer having a phosphate group or a (meth)acrylate polymerizable monomer having a carboxylic acid group, from the viewpoint of having good adhesive strength when used as a resin composition for photocurable orthodontic appliances, such as 10-(meth)acryloyloxydecyl dihydrogen phosphate, 4-(meth)acryloyloxyethyl trimellitate anhydride, 4-(meth)acryloyloxyethyl trimellitate, 11- (meth)acryloyloxyundecane-1,1-dicarboxylic acid and a mixture of 2-methacryloyloxyethyl dihydrogen phosphate and bis(2-methacryloyloxyethyl)hydrogen phosphate are more preferred, 10-(meth)acryloyloxydecyl dihydrogen phosphate and 4-(meth)acryloyloxyethyl trimellitate anhydride are even more preferred, and 10-(meth)acryloyloxydecyl dihydrogen phosphate is most preferred.

[0031] When the photocurable resin composition for orthodontic appliances of the present invention contains a polymerizable monomer (A-1) having an acidic group, the content of the polymerizable monomer (A-1) having an acidic group in the photocurable resin composition for orthodontic appliances of the present invention is preferably 1 to 50% by mass, more preferably 2.5 to 40% by mass, and even more preferably 5 to 30% by mass, based on the total amount of polymerizable monomer (A).

[0032] • Polymerizable monomer without acidic groups (A-2) Examples of polymerizable monomers (A-2) without acidic groups in the present invention include asymmetric acrylamide-methacrylate ester compounds (A-2a); hydrophobic polymerizable monomers (A-2b) without acidic groups, having a solubility of less than 10% by mass in water at 25°C; and hydrophilic polymerizable monomers (A-2c) with acidic groups having a solubility of 10% by mass or more in water at 25°C. One type of polymerizable monomer (A-2) without acidic groups may be used alone, or two or more types may be used in combination. In the present invention, compounds that do not have acidic groups and contain an acrylamide group and a methacryloyloxy group are defined as asymmetric acrylamide-methacrylate ester compounds (A-2a), and compounds that do not have acidic groups and are not included in asymmetric acrylamide-methacrylate ester compounds (A-2a) are divided into hydrophobic polymerizable monomers (A-2b) and hydrophilic polymerizable monomers (A-2c) according to the degree of hydrophilicity.

[0033] • Asymmetric acrylamide-methacrylate ester compound (A-2a) One preferred embodiment is a photocurable orthodontic resin composition in which the polymerizable monomer (A) further comprises an asymmetric acrylamide-methacrylate compound (A-2a). The asymmetric acrylamide-methacrylate compound (A-2a) is preferably a compound represented by the following general formula (1) because it improves the adhesion of the photocurable orthodontic resin composition to tooth structure.

[0034] [ka] In the formula, Z is a C1-C8 linear or branched aliphatic or aromatic group which may have substituents, and the aliphatic group is -O-, -S-, -CO-, -CO-O-, -O-CO-, -NR 1 -,-CO-NR 1 -, -NR 1 -CO-, -CO-O-NR 1 -, -O-CO-NR 1 - and -NR 1 -CO-NR 1- May be interrupted by at least one bonding group selected from the group consisting of -. 1 This represents a linear or branched aliphatic group of C1 to C8, which may have a hydrogen atom or substituents.

[0035] Z is a site that adjusts the hydrophilicity of the asymmetric acrylamide-methacrylate compound (A-2a). The C1-C8 aliphatic group represented by Z, which may have substituents, may be either a saturated aliphatic group (alkylene group, cycloalkylene group (e.g., 1,4-cyclohexylene group, etc.)) or an unsaturated aliphatic group (alkenylene group, alkylylene group), and is preferably a saturated aliphatic group (alkylene group) from the viewpoint of ease of acquisition or manufacture and chemical stability. From the viewpoint of adhesion to tooth structure and polymerization curability, Z is preferably a linear or branched C1-C4 aliphatic group which may have substituents, and more preferably a linear or branched C2-C4 aliphatic group which may have substituents. An alkylene group is preferred as the aliphatic group. Examples of the C1-C8 alkylene group include a methylene group, an ethylene group, an n-propylene group, an isopropylene group, and an n-butylene group.

[0036] Examples of aromatic groups that may have substituents represented by Z include aryl groups and aromatic heterocyclic groups. Aryl groups are preferred as the aromatic group. The heterocyclic ring of an aromatic heterocyclic group is generally unsaturated. The aromatic heterocyclic ring is preferably a 5-membered or 6-membered ring. A phenyl group is preferred as the aryl group. Examples of aromatic heterocyclic groups include furan groups, thiophene groups, pyrrole groups, oxazole groups, isoxazole groups, thiazole groups, isothiazole groups, imidazole groups, pyrazole groups, furazan groups, triazole groups, pyran groups, pyridine groups, pyridazine groups, pyrimidine groups, pyrazine groups, and 1,3,5-triazine groups. Of the aromatic groups, the phenyl group is particularly preferred.

[0037] R 1The aliphatic group in X may be either a saturated aliphatic group (alkyl group) or an unsaturated aliphatic group (alkenyl group, alkynyl group), but a saturated aliphatic group (alkyl group) is preferred from the viewpoint of ease of acquisition or manufacture and chemical stability. Examples of the alkyl group are the same as those described as substituents in X.

[0038] R 1 More preferably, linear or branched C1-C4 alkyl groups may have hydrogen atoms or substituents, and even more preferably, linear or branched C1-C3 alkyl groups may have hydrogen atoms or substituents.

[0039] When the aliphatic group of Z is interrupted by the bonding group, the number of bonding groups is not particularly limited, but may be around 1 to 10, preferably 1, 2, or 3, and more preferably 1 or 2. Furthermore, in formula (1), it is preferable that the aliphatic group of Z is not interrupted by consecutive bonding groups. That is, it is preferable that the bonding groups are not adjacent to each other. As bonding groups, at least one bonding group selected from the group consisting of -O-, -S-, -CO-, -CO-O-, -O-CO-, -NH-, -CO-NH-, -NH-CO-, -CO-O-NH-, -O-CO-NH-, and -NH-CO-NH- is more preferable, and at least one bonding group selected from the group consisting of -O-, -S-, -CO-, -NH-, -CO-NH-, and -NH-CO- is particularly preferable.

[0040] Substituents in Z include halogen atoms (fluorine atoms, chlorine atoms, bromine atoms, iodine atoms), carboxyl groups, linear or branched acyl groups of C2 to C6, linear or branched alkyl groups of C1 to C6, and linear or branched alkoxy groups of C1 to C6.

[0041] Specific examples of asymmetric acrylamide-methacrylate compounds (A-2a) are not limited to the following:

[0042] [ka]

[0043] Among these, asymmetric acrylamide / methacrylate ester compounds in which Z is a linear or branched aliphatic group of C2-C4 which may have substituents are preferred from the viewpoint of adhesion to tooth structure and polymerization hardening properties. More preferably, N-methacryloyloxyethyl acrylamide (commonly known as "MAEA"), N-methacryloyloxypropyl acrylamide, N-methacryloyloxybutyl acrylamide, N-(1-ethyl-(2-methacryloyloxy)ethyl) acrylamide, and N-(2-(2-methacryloyloxyethoxy)ethyl) acrylamide are preferred, and MAEA and N-methacryloyloxypropyl acrylamide are most preferred from the viewpoint of high hydrophilicity involved in penetration into the collagen layer of dentin.

[0044] The asymmetric acrylamide-methacrylate compound (A-2a) may be formulated alone or in combination of two or more types. The content of the asymmetric acrylamide-methacrylate compound (A-2a) is not particularly limited as long as the effects of the present invention are achieved, but it is preferably in the range of 1 to 60% by mass, more preferably in the range of 2 to 45% by mass, even more preferably in the range of 3 to 30% by mass, and particularly preferably in the range of 5 to 25% by mass, of the total amount of polymerizable monomer (A) in the photocurable orthodontic resin composition of the present invention.

[0045] • Hydrophobic polymerizable monomer without acidic groups (A-2b) A hydrophobic polymerizable monomer (A-2b) that does not have an acidic group (hereinafter sometimes simply referred to as "hydrophobic polymerizable monomer (A-2b)") improves the handling properties of a photocurable orthodontic resin composition or the mechanical strength of its cured product. As the hydrophobic polymerizable monomer (A-2b), a radical polymerizable monomer that does not have an acidic group but has a polymerizable group is preferred, and from the viewpoint of easy radical polymerization, the polymerizable group is preferably a (meth)acrylic group and / or a (meth)acrylamide group. A hydrophobic polymerizable monomer (A-2b) means a polymerizable monomer that does not have an acidic group, does not correspond to an asymmetric acrylamide-methacrylate ester compound (A-2a), and has a solubility in water at 25°C of less than 10% by mass. Examples of hydrophobic polymerizable monomers (A-2b) include crosslinkable polymerizable monomers such as difunctional polymerizable monomers based on aromatic compounds, difunctional polymerizable monomers based on aliphatic compounds, and polymerizable monomers with three or more functionalities.

[0046] Examples of bifunctional polymerizable monomers of aromatic compounds include 2,2-bis((meth)acryloyloxyphenyl)propane, 2,2-bis[4-(3-(meth)acryloyloxy-2-hydroxypropoxy)phenyl]propane, 2,2-bis(4-(meth)acryloyloxyethoxyphenyl)propane, 2,2-bis(4-(meth)acryloyloxypolyethoxyphenyl)propane, 2,2-bis(4-(meth)acryloyloxydiethoxyphenyl)propane, 2,2-bis(4-(meth)acryloyloxytriethoxyphenyl)propane, 2,2-bis(4-(meth)acryloyloxytetraethoxyphenyl)propane, and 2,2-bis(4-(meth)acryloyloxypentaethoxyphenyl) Examples include xyphenyl)propane, 2,2-bis(4-(meth)acryloyloxydipropoxyphenyl)propane, 2-(4-(meth)acryloyloxydiethoxyphenyl)-2-(4-(meth)acryloyloxyethoxyphenyl)propane, 2-(4-(meth)acryloyloxydiethoxyphenyl)-2-(4-(meth)acryloyloxytriethoxyphenyl)propane, 2-(4-(meth)acryloyloxydipropoxyphenyl)-2-(4-(meth)acryloyloxytriethoxyphenyl)propane, 2,2-bis(4-(meth)acryloyloxypropoxyphenyl)propane, and 2,2-bis(4-(meth)acryloyloxyisopropoxyphenyl)propane. Among these, 2,2-bis[4-(3-methacryloyloxy-2-hydroxypropoxy)phenyl]propane (commonly known as "Bis-GMA"), 2,2-bis(4-(meth)acryloyloxyethoxyphenyl)propane, 2,2-bis(4-methacryloyloxypolyethoxyphenyl)propane (average number of moles of ethoxy groups added: 2.6, commonly known as "D-2.6E"), 2,2-bis(4-(meth)acryloyloxydiethoxyphenyl)propane, 2,2-bis(4-(meth)acryloyloxytriethoxyphenyl)propane, 2,2-bis(4-(meth)acryloyloxytetraethoxyphenyl)propane, and 2,2-bis(4-(meth)acryloyloxypentaethoxyphenyl)propane are preferred.

[0047] Examples of aliphatic compound-based bifunctional polymerizable monomers include glycerol di(meth)acrylate, ethylene glycol di(meth)acrylate, diethylene glycol di(meth)acrylate, triethylene glycol di(meth)acrylate, propylene glycol di(meth)acrylate, butylene glycol di(meth)acrylate, neopentyl glycol di(meth)acrylate, 1,3-butanediol di(meth)acrylate, 1,5-pentanediol di(meth)acrylate, 1,6-hexanediol di(meth)acrylate, 1,10-decanediol di(meth)acrylate, 1,2-bis(3-methacryloyloxy-2-hydroxypropoxy)ethane, 2,2,4-trimethylhexamethylenebis(2-carbamoyloxyethyl)di(meth)acrylate, N-methacryloyloxyethyl acrylamide, and N-methacryloyloxypropylamide. Among these, triethylene glycol diacrylate, triethylene glycol dimethacrylate (commonly known as "3G"), neopentyl glycol di(meth)acrylate, 1,2-bis(3-methacryloyloxy-2-hydroxypropoxy)ethane, 2,2,4-trimethylhexamethylenebis(2-carbamoyloxyethyl) dimethacrylate (commonly known as "UDMA"), 1,10-decanediol dimethacrylate (commonly known as "DD"), and 2,2,4-trimethylhexamethylenebis(2-carbamoyloxyethyl) dimethacrylate are preferred.

[0048] Examples of polymerizable monomers with three or more functionalities include trimethylolpropane tri(meth)acrylate, trimethylolethane tri(meth)acrylate, trimethylolmethane tri(meth)acrylate, pentaerythritol tri(meth)acrylate, pentaerythritol tetra(meth)acrylate, dipentaerythritol penta(meth)acrylate, N,N-(2,2,4-trimethylhexamethylene)bis[2-(aminocarboxy)propane-1,3-diol]tetra(meth)acrylate, and 1,7-diacryloyloxy-2,2,6,6-tetra(meth)acryloyloxymethyl-4-oxaheptane. Among these, N,N-(2,2,4-trimethylhexamethylene)bis[2-(aminocarboxy)propane-1,3-diol]tetramethacrylate is preferred.

[0049] Among the hydrophobic polymerizable monomers (A-2b) described above, aromatic compound-based difunctional polymerizable monomers and aliphatic compound-based difunctional polymerizable monomers are preferably used from the viewpoint of mechanical strength or handling properties. Preferred aromatic compound-based difunctional polymerizable monomers are Bis-GMA and D-2.6E. Preferred aliphatic compound-based difunctional polymerizable monomers are glycerol di(meth)acrylate, 3G, neopentyl glycol di(meth)acrylate, 1,6-hexanediol di(meth)acrylate, DD, 1,2-bis(3-methacryloyloxy-2-hydroxypropoxy)ethane, and UDMA. One preferred embodiment is a photocurable orthodontic resin composition in which the hydrophobic polymerizable monomer (A-2b) without acidic groups contains a hydrophobic polymerizable monomer having hydroxyl groups (e.g., Bis-GMA).

[0050] Among the hydrophobic polymerizable monomers (A-2b) described above, Bis-GMA, D-2.6E, 3G, UDMA, and DD are more preferred, and D-2.6E and DD are even more preferred, from the viewpoint of good adhesion to tooth structure when used as a resin composition for photocurable orthodontic appliances.

[0051] The hydrophobic polymerizable monomer (A-2b) may be blended alone or in combination of two or more types. When the photocurable resin composition for orthodontic appliances of the present invention contains a polymerizable monomer (A-1) having an acidic group, the content of the hydrophobic polymerizable monomer (A-2b) is preferably in the range of 20 to 99% by mass, more preferably in the range of 40 to 95% by mass, and even more preferably in the range of 60 to 95% by mass, of the total amount of polymerizable monomer (A). When the content of the hydrophobic polymerizable monomer (A-2b) is within the above range, the wettability of the composition to the tooth structure does not decrease, sufficient adhesion is obtained, and sufficient strength of the cured product is obtained. When polymerizable monomer (A) does not contain a polymerizable monomer (A-1) having an acidic group, the content of the hydrophobic polymerizable monomer (A-2b) may be 100% by mass of the total amount of polymerizable monomer (A).

[0052] • Hydrophilic polymerizable monomer (A-2c) that does not have an acidic group The photocurable resin composition for orthodontic appliances of the present invention preferably further contains a hydrophilic polymerizable monomer (A-2c) (hereinafter sometimes simply referred to as "hydrophilic polymerizable monomer (A-2c)") in which the polymerizable monomer (A) does not have an acidic group. The hydrophilic polymerizable monomer (A-2c) improves the wettability of the components of the photocurable resin composition for orthodontic appliances to tooth structure. As the hydrophilic polymerizable monomer, a radical polymerizable monomer having a polymerizable group but not an acidic group is preferred, and from the viewpoint of easy radical polymerization, the polymerizable group is preferably a (meth)acrylic group and / or a (meth)acrylamide group. The hydrophilic polymerizable monomer (A-2c) means one that does not have an acidic group, does not correspond to an asymmetric acrylamide-methacrylate ester compound (A-2a), and has a solubility in water at 25°C of 10% by mass or more, preferably one with a solubility of 30% by mass or more, and more preferably one that can dissolve in water in any proportion at 25°C. As hydrophilic polymerizable monomers (A-2c), those having hydrophilic groups such as hydroxyl groups, oxymethylene groups, oxyethylene groups, oxypropylene groups, and amide groups are preferred. Examples of hydrophilic polymerizable monomers (A-2c) include hydrophilic monofunctional (meth)acrylate polymerizable monomers such as 2-hydroxyethyl (meth)acrylate, 3-hydroxypropyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, 1,3-dihydroxypropyl (meth)acrylate, 2,3-dihydroxypropyl (meth)acrylate, 2-((meth)acryloyloxy)ethyltrimethylammonium chloride, and polyethylene glycol di(meth)acrylate (with 9 or more oxyethylene groups);N Examples include hydrophilic monofunctional (meth)acrylamide polymerizable monomers such as methylol(meth)acrylamide, N-hydroxyethyl(meth)acrylamide, N,N-bis(2-hydroxyethyl)(meth)acrylamide, N-methoxymethyl(meth)acrylamide, N-ethoxymethyl(meth)acrylamide, diacetone(meth)acrylamide, 4-(meth)acryloylmorpholine, N-trihydroxymethyl-N-methyl(meth)acrylamide, N,N-dimethylacrylamide, and N,N-diethylacrylamide.

[0053] Among these hydrophilic polymerizable monomers (A-2c), 2-hydroxyethyl (meth)acrylate, 2,3-dihydroxypropyl (meth)acrylate, and hydrophilic monofunctional (meth)acrylamide polymerizable monomers are preferred from the viewpoint of adhesion to tooth structure, and 2-hydroxyethyl (meth)acrylate, N,N-dimethylacrylamide, and N,N-diethylacrylamide are more preferred. Hydrophilic polymerizable monomers (A-2c) may be formulated individually or in combination of two or more.

[0054] If the content of the hydrophilic polymerizable monomer (A-2c) in the present invention is too low, the effect of improving adhesion may not be sufficiently obtained, and if it is too high, the mechanical strength may decrease. Therefore, the content of the hydrophilic polymerizable monomer (A-2c) in the photocurable resin composition for orthodontic appliances of the present invention is preferably in the range of 0 to 50% by mass, more preferably in the range of 0 to 40% by mass, and even more preferably in the range of 0 to 30% by mass, of the total amount of polymerizable monomer (A). The content of the hydrophilic polymerizable monomer (A-2c) may be 0% by mass.

[0055] The content of polymerizable monomers (A-2) that do not have acidic groups is preferably 50 to 99% by mass, more preferably 60 to 95% by mass, and even more preferably 70 to 90% by mass, in relation to the total amount of polymerizable monomers (A). Furthermore, from the viewpoint of adhesion, etc., the mass ratio of hydrophilic polymerizable monomers (A-2c) to hydrophobic polymerizable monomers (A-2b) is preferably hydrophilic polymerizable monomers (A-2c):hydrophobic polymerizable monomers (A-2b) = 0:10 to 2:1, more preferably 0:10 to 1:1, and even more preferably 0:10 to 1:2. In one embodiment, it is preferable that the polymerizable monomer (A) contains 1 to 50 parts by mass of polymerizable monomer (A-1) having an acidic group and 50 to 99 parts by mass of polymerizable monomer (A-2) without an acidic group, more preferably 2.5 to 40 parts by mass of polymerizable monomer (A-1) having an acidic group and 60 to 95 parts by mass of polymerizable monomer (A-2) without an acidic group, and even more preferably 5 to 30 parts by mass of polymerizable monomer (A-1) having an acidic group and 70 to 90 parts by mass of polymerizable monomer (A-2) without an acidic group.

[0056] Photopolymerization initiator (B) Photopolymerization initiators (B) are classified into water-soluble photopolymerization initiators (B-1) and water-insoluble photopolymerization initiators (B-2). As for photopolymerization initiators (B), water-soluble photopolymerization initiators (B-1) may be used alone, water-insoluble photopolymerization initiators (B-2) may be used alone, or water-soluble photopolymerization initiators (B-1) and water-insoluble photopolymerization initiators (B-2) may be used in combination.

[0057] • Water-soluble photopolymerization initiator (B-1) The water-soluble photopolymerization initiator (B-1) improves polymerization curing at hydrophilic tooth surface interfaces, enabling high adhesive strength. The water-soluble photopolymerization initiator (B-1) has a solubility in water at 25°C of 10 g / L or more, preferably 15 g / L or more, more preferably 20 g / L or more, and even more preferably 25 g / L or more. If the solubility is less than 10 g / L, the water-soluble photopolymerization initiator (B-1) will not dissolve sufficiently in the water in the tooth structure at the adhesive interface, making it difficult for the polymerization-promoting effect to be exhibited.

[0058] Examples of water-soluble photopolymerization initiators (B-1) include water-soluble acylphosphine oxides, water-soluble thioxanthones, 1-[4-(2-hydroxyethoxy)-phenyl]-2-hydroxy-2-methyl-1-propan-1-one with a (poly)ethylene glycol chain introduced to the hydroxyl group, 1-hydroxycyclohexyl phenyl ketone with a (poly)ethylene glycol chain introduced to the hydroxyl group and / or phenyl group, and -OCH2COO - Na + A modified version of 2-hydroxy-2-methyl-1-phenylpropan-1-one, in which a (poly)ethylene glycol chain is introduced to the hydroxyl group and / or phenyl group of 2-hydroxy-2-methyl-1-phenylpropan-1-one, with -OCH2COO added to the phenyl group of 2-hydroxy-2-methyl-1-phenylpropan-1-one. - Na +Examples include α-hydroxyalkylacetophenones with the introduction of 2-methyl-1[4-(methylthio)phenyl]-2-morpholinopropan-1-one and 2-benzyl-2-(dimethylamino)-1-[(4-morpholino)phenyl]-1-butanone, in which the amino group of α-aminoalkylphenones has been quaternarily ammonium-chlorinated.

[0059] Examples of the water-soluble thioxanthones include 2-hydroxy-3-(9-oxo-9H-thioxanthene-4-yloxy)-N,N,N-trimethyl-1-propaneaminium chloride, 2-hydroxy-3-(1-methyl-9-oxo-9H-thioxanthene-4-yloxy)-N,N,N-trimethyl-1-propaneaminium chloride, 2-hydroxy-3-(9-oxo-9H-thioxanthene-2-yloxy)-N,N,N-trimethyl-1-propaneaminium chloride, 2- Hydroxy-3-(3,4-dimethyl-9-oxo-9H-thioxanthene-2-yloxy)-N,N,N-trimethyl-1-propaneaminium chloride, 2-hydroxy-3-(3,4-dimethyl-9H-thioxanthene-2-yloxy)-N,N,N-trimethyl-1-propaneaminium chloride, 2-hydroxy-3-(1,3,4-trimethyl-9-oxo-9H-thioxanthene-2-yloxy)-N,N,N-trimethyl-1-propaneaminium chloride, etc., can be used.

[0060] Examples of the aforementioned water-soluble acylphosphine oxides include those represented by the following general formulas (2) or (3).

[0061] [ka]

[0062] [ka]

[0063] In equations (2) and (3), R2 , R 3 , R 4 , R 5 , R 6 , and R 7 These are, independently of each other, a linear or branched C1-C4 alkyl group or halogen atom, in formula (2), where M is a hydrogen ion, alkali metal ion, alkaline earth metal ion, magnesium ion, pyridinium ion (the pyridine ring may have substituents), or HN + R 9 R 10 R 11 (In the formula, R 9 , R 10 , and R 11 R is an ammonium ion represented independently by an organic group or a hydrogen atom, and n is 1 or 2. In formula (3), X is a linear or branched alkylene group of C1 to C4, and R 8 -CH(CH3)COO(C2H4O) p It is represented as CH3, where p represents an integer between 1 and 1000.

[0064] R 2 , R 3 , R 4 , R 5 , R 6 , and R 7 The alkyl group is not particularly limited as long as it is a linear or branched C1-C4 group, and examples include methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, isobutyl group, sec-butyl group, 2-methylpropyl group, tert-butyl group, etc. 2 , R 3 , R 4 , R 5 , R 6 , and R 7 The alkyl group of X is preferably a linear alkyl group with 1 to 3 carbon atoms, more preferably a methyl group or an ethyl group, and even more preferably a methyl group. The alkylene group of X is preferably a methylene group, an ethylene group, an n-propylene group, an isopropylene group, or an n-butylene group. The alkylene group of X is preferably a linear alkylene group with 1 to 3 carbon atoms, more preferably a methylene group or an ethylene group, and even more preferably a methylene group.

[0065] When M is a pyridinium ion, substituents on the pyridine ring include halogen atoms (fluorine, chlorine, bromine, iodine), carboxyl groups, linear or branched acyl groups of C2-C6, linear or branched alkyl groups of C1-C6, and linear or branched alkoxy groups of C1-C6. M can be an alkali metal ion, an alkaline earth metal ion, a magnesium ion, a pyridinium ion (the pyridine ring may have substituents), or HN + R 9 R 10 R 11 Ammonium ions represented by (wherein the formula, the symbols have the same meaning as above) are preferred. Examples of alkali metal ions include lithium ions, sodium ions, potassium ions, rubidium ions, and cesium ions. Examples of alkaline earth metal ions include calcium ions, strontium ions, barium ions, and radium ions. R 9 , R 10 , and R 11 Examples of organic groups include those similar to the substituents on the pyridine ring (excluding halogen atoms).

[0066] Among these, in equations (2) and (3), R 2 , R 3 , R 4 , R 5 , R 6 , and R 7 Compounds in which all are methyl groups are particularly preferred in terms of storage stability and color stability in the composition. On the other hand, M n+ For example, Li + kaNa + , K + Ca 2+ Mg 2+, ammonium ions derived from various amines can be mentioned. Examples of amines include ammonia, trimethylamine, diethylamine, dimethylaniline, ethylenediamine, triethanolamine, N,N-dimethylaminomethacrylate, 4-(N,N-dimethylamino)benzoic acid and its alkyl esters, 4-(N,N-diethylamino)benzoic acid and its alkyl esters, N,N-bis(2-hydroxyethyl)-p-toluidine, and the like. R 8 From the viewpoint of adhesion, p is preferably 1 or more, more preferably 2 or more, further preferably 3 or more, particularly preferably 4 or more, preferably 1000 or less, more preferably 100 or less, further preferably 75 or less, and particularly preferably 50 or less.

[0067] Among these water-soluble acylphosphine oxides, those represented by the general formula (2), M n+ is Li + compounds of the general formula (2), and R 8 a compound represented by the general formula (3) synthesized from polyethylene glycol methyl ether methacrylate in which the portion corresponding to the group represented by is a molecular weight of 950 is particularly preferred. In these compounds, R 2 , R 3 , and R 4 , and R 2 , R 3 , R 4 , R 5 , R 6 , and R 7 are as described above.

[0068] Water-soluble acylphosphine oxides having such a structure can be synthesized according to known methods, and some are also available as commercial products. For example, they can be synthesized by the methods disclosed in JP-A-57-197289 and WO 2014 / 095724. The water-soluble photopolymerization initiator (B-1) may be used alone or in combination of two or more.

[0069] The water-soluble photopolymerization initiator (B-1) may be dissolved in the photocurable orthodontic resin composition or dispersed as a powder within the composition.

[0070] When dispersing the water-soluble photopolymerization initiator (B-1) in powder form, if the average particle size is too large, it tends to settle, so a size of 500 μm or less is preferred, more preferably 100 μm or less, and even more preferably 50 μm or less. On the other hand, if the average particle size is too small, the specific surface area of ​​the powder becomes too large, reducing the amount that can be dispersed in the composition, so a size of 0.01 μm or more is preferred. In other words, the average particle size of the water-soluble photopolymerization initiator (B-1) is preferably in the range of 0.01 to 500 μm, more preferably in the range of 0.01 to 100 μm, and even more preferably in the range of 0.01 to 50 μm.

[0071] The average particle size of each water-soluble photopolymerization initiator (B-1) powder can be calculated as the volume-average particle size after performing image analysis using image analysis-based particle size distribution measurement software (Mac-View; manufactured by Mountec Co., Ltd.) based on electron microscope images of 100 or more particles.

[0072] When the water-soluble photopolymerization initiator (B-1) is dispersed as a powder, various shapes of the initiator can be used, such as spherical, needle-shaped, plate-shaped, or crushed, but there are no particular limitations. The water-soluble photopolymerization initiator (B-1) can be prepared by conventionally known methods such as grinding, freeze-drying, or reprecipitation. From the viewpoint of the average particle size of the resulting powder, freeze-drying and reprecipitation are preferred, and freeze-drying is more preferred.

[0073] From the viewpoint of curability of the resulting photocurable orthodontic resin composition, the content of the water-soluble photopolymerization initiator (B-1) is preferably 0.01 to 20% by mass of the total amount of polymerizable monomer (A) in the photocurable orthodontic resin composition of the present invention, more preferably 0.05 to 10% by mass, and even more preferably 0.1 to 5% by mass, from the viewpoint of adhesion to tooth structure. If the content of the water-soluble photopolymerization initiator (B-1) is less than 0.01% by mass, polymerization at the adhesive interface may not proceed sufficiently, which may lead to a decrease in adhesive strength. On the other hand, if the content of the water-soluble photopolymerization initiator (B-1) exceeds 20% by mass, if the polymerization performance of the water-soluble photopolymerization initiator (B-1) is low, sufficient adhesive strength may not be obtained, and furthermore, dissolution, dispersion, and diffusion in the photocurable orthodontic resin composition may be insufficient.

[0074] • Non-water-soluble photopolymerization initiator (B-2) The photocurable resin composition for orthodontic appliances of the present invention preferably contains a water-insoluble photopolymerization initiator (B-2) (hereinafter referred to as water-insoluble photopolymerization initiator (B-2)) having a solubility in water at 25°C of less than 10 g / L, from the viewpoint of curability. The water-insoluble photopolymerization initiator (B-2) used in the present invention can be any known photopolymerization initiator. The water-insoluble photopolymerization initiator (B-2) may be included alone or in combination of two or more.

[0075] Examples of non-water-soluble photopolymerization initiators (B-2) include (bis)acylphosphine oxides, thioxanthones, ketals, α-diketones, coumarins, anthraquinones, benzoin alkyl ether compounds, and α-aminoketone compounds, in addition to the water-soluble photopolymerization initiators (B-1).

[0076] Among the (bis)acylphosphine oxides mentioned above, examples of 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, and benzoyldi(2,6-dimethylphenyl)phosphonate. Examples of 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.

[0077] Examples of the thioxanthones include thioxanthone and 2-chlorothioxanthene-9-one.

[0078] Examples of the aforementioned ketals include benzyldimethyl ketal and benzyldiethyl ketal.

[0079] Examples of the α-diketones include diacetyl, benzyl, dl-camphorquinone, 2,3-pentadione, 2,3-octadione, 9,10-phenanthrenequinone, 4,4'-oxybenzyl, and acenaphthenequinone. Among these, dl-camphorquinone is particularly preferred from the viewpoint of having a maximum absorption wavelength in the visible light range.

[0080] Examples of the aforementioned coumarins include 3,3'-carbonylbis(7-diethylaminocoumarin), 3-(4-methoxybenzoyl)coumarin, 3-thienoylcoumarin, 3-benzoyl-5,7-dimethoxycoumarin, 3-benzoyl-7-methoxycoumarin, 3-benzoyl-6-methoxycoumarin, 3-benzoyl-8-methoxycoumarin, 3-benzoylcoumarin, 7-methoxy-3-(p-nitrobenzoyl)coumarin, 3-(p-nitrobenzoyl)coumarin, 3,5-carbonylbis(7-methoxycoumarin), and 3-benzoyl-6-bromo Coumarin, 3,3'-carbonylbiscoumarin, 3-benzoyl-7-dimethylaminocoumarin, 3-benzoylbenzo[f]coumarin, 3-carboxycoumarin, 3-carboxy-7-methoxycoumarin, 3-ethoxycarbonyl-6-methoxycoumarin, 3-ethoxycarbonyl-8-methoxycoumarin, 3-acetylbenzo[f]coumarin, 3-benzoyl-6-nitrocoumarin, 3-benzoyl-7-diethylaminocoumarin, 7-dimethylamino-3-(4-methoxybenzoyl)coumarin, 7-diethylamino-3-(4-methoxybenzoyl Coumarin, 7-diethylamino-3-(4-diethylamino)coumarin, 7-methoxy-3-(4-methoxybenzoyl)coumarin, 3-(4-nitrobenzoyl)benzo[f]coumarin, 3-(4-ethoxycinnamoyl)-7-methoxycoumarin, 3-(4-dimethylaminocinnamoyl)coumarin, 3-(4-diphenylaminocinnamoyl)coumarin, 3-[(3-dimethylbenzothiazole-2-ylidene)acetyl]coumarin, 3-[(1-methylnaphtho[1,2-d]thiazole-2-ylidene)acetyl]coumarin, 3,3'-carb Nylbis(6-methoxycoumarin), 3,3'-carbonylbis(7-acetoxycoumarin), 3,3'-carbonylbis(7-dimethylaminocoumarin), 3-(2-benzothiazolyl)-7-(diethylamino)coumarin, 3-(2-benzothiazolyl)-7-(dibutylamino)coumarin, 3-(2-benzoimidazolyl)-7-(diethylamino)coumarin, 3-(2-benzothiazolyl)-7-(dioctylamino)coumarin, 3-acetyl-7-(dimethylamino)coumarin, 3,3'-carbonylbis(7-dibutylaminocoumarin), 3,Examples of compounds described in Japanese Patent Publication No. 9-3109 and Japanese Patent Publication No. 10-245525 include 3'-carbonyl-7-diethylaminocoumarin-7'-bis(butoxyethyl)aminocoumarin, 10-[3-[4-(dimethylamino)phenyl]-1-oxo-2-propenyl]-2,3,6,7-tetrahydro-1,1,7,7-tetramethyl-1H,5H,11H-[1]benzopyrano[6,7,8-ij]quinoridine-11-one, and 10-(2-benzothiazolyl)-2,3,6,7-tetrahydro-1,1,7,7-tetramethyl-1H,5H,11H-[1]benzopyrano[6,7,8-ij]quinoridine-11-one.

[0081] Among the coumarins mentioned above, 3,3'-carbonylbis(7-diethylaminocoumarin) and 3,3'-carbonylbis(7-dibutylaminocoumarin) are particularly preferred.

[0082] Examples of the aforementioned anthraquinones include anthraquinone, 1-chloroanthraquinone, 2-chloroanthraquinone, 1-bromoanthraquinone, 1,2-benzanthraquinone, 1-methylanthraquinone, 2-ethylanthraquinone, and 1-hydroxyanthraquinone.

[0083] Examples of the benzoin alkyl ether compounds include benzoin methyl ether, benzoin ethyl ether, benzoin isopropyl ether, and benzoin isobutyl ether.

[0084] Examples of the α-aminoketone compounds include 2-methyl-1-[4-(methylthio)phenyl]-2-morpholinopropan-1-one.

[0085] Among these water-insoluble photopolymerization initiators (B-2), it is preferable to use at least one selected from the group consisting of (bis)acylphosphine oxides, α-diketones, and coumarins. This results in a photocurable resin composition for orthodontic appliances that exhibits excellent photocurability in the visible and near-ultraviolet regions and sufficient photocurability regardless of whether a halogen lamp, light-emitting diode (LED), or xenon lamp is used as the light source.

[0086] The content of the non-water-soluble photopolymerization initiator (B-2) is not particularly limited, but from the viewpoint of the curability of the resulting composition, the content of the non-water-soluble photopolymerization initiator (B-2) is preferably in the range of 0.01 to 10% by mass, more preferably in the range of 0.05 to 7% by mass, and even more preferably in the range of 0.1 to 5% by mass, of the total amount of polymerizable monomer (A) in the photocurable orthodontic resin composition of the present invention. If the content of the non-water-soluble photopolymerization initiator (B-2) exceeds 10% by mass, sufficient adhesive strength may not be obtained, and furthermore, precipitation from the photocurable orthodontic resin composition may occur.

[0087] When a water-soluble photopolymerization initiator (B-1) and a water-insoluble photopolymerization initiator (B-2) are used in combination, the mass ratio of the water-soluble photopolymerization initiator (B-1):(B-2) in the present invention is preferably 10:1 to 1:10, more preferably 7:1 to 1:7, even more preferably 5:1 to 1:5, and most preferably 3:1 to 1:3. If the amount of water-soluble photopolymerization initiator (B-1) is greater than 10:1 by mass, the curability of the photocurable orthodontic resin composition itself decreases, making it difficult to achieve high adhesive strength. On the other hand, if the amount of water-insoluble photopolymerization initiator (B-2) is greater than 1:10 by mass, although the curability of the photocurable orthodontic resin composition itself is increased, the polymerization promotion at the adhesive interface becomes insufficient, making it difficult to achieve high adhesive strength.

[0088] Filler (C) The photocurable resin composition for orthodontic appliances of the present invention contains a filler (C) to adjust handling properties and to increase the mechanical strength of the cured product. Such fillers include inorganic fillers and organic-inorganic composite fillers. Examples of organic filler materials include polymethyl methacrylate, polyethyl methacrylate, methyl methacrylate-ethyl methacrylate copolymer, crosslinked polymethyl methacrylate, crosslinked polyethyl methacrylate, polyamide, polyvinyl chloride, polystyrene, chloroprene rubber, nitrile rubber, ethylene-vinyl acetate copolymer, styrene-butadiene copolymer, acrylonitrile-styrene copolymer, and acrylonitrile-styrene-butadiene copolymer. These may be used individually or as a mixture 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. From the viewpoint of handling properties and mechanical strength of the resulting photocurable orthodontic resin composition, the average particle size of the organic filler is preferably 0.001 to 50 μm, and more preferably 0.001 to 10 μm. In this specification, if the inorganic filler is surface-treated as described below, the average particle size of the inorganic filler refers to the average particle size before surface treatment.

[0089] Examples of inorganic filler materials include quartz, silica, alumina, silica-titania, silica-titania-barium oxide, 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, strontium calcium fluoroaluminosilicate glass, ytterbium oxide, and silica-coated ytterbium fluoride. These can be used individually or mixed in combination of two or more. The shape of the inorganic filler is not particularly limited, and the particle size of the filler can be appropriately selected. Among these, quartz, silica, silica-zirconia, barium glass, ytterbium oxide, and silica-coated ytterbium fluoride are preferred, and more preferably, quartz, silica, silica-zirconia, barium glass, and silica-coated ytterbium fluoride are used, due to their excellent mechanical strength and transparency in the resulting photocurable orthodontic resin composition. From the viewpoint of handling properties and mechanical strength of the resulting composition, the average particle size of the inorganic filler is preferably 0.001 to 50 μm, and more preferably 0.001 to 10 μm.

[0090] Examples of inorganic filler shapes include amorphous fillers and spherical fillers. From the viewpoint of improving the mechanical strength of the cured product of the photocurable resin composition for orthodontic appliances, it is preferable to use spherical fillers as the inorganic filler. Furthermore, when spherical fillers are used, there is also the advantage that when the photocurable resin composition for orthodontic appliances of the present invention is used as a dental attachment for aligner orthodontics, a dental attachment with excellent surface smoothness can be obtained. Here, a spherical filler is a filler in which, when a photograph of the filler is taken with an electron microscope, the particles observed within the unit field of view are rounded, and the average uniformity obtained by dividing the particle diameter in the direction perpendicular to the maximum diameter by the maximum diameter is 0.6 or more. The average particle diameter of the spherical filler is preferably 0.05 to 5 μm. If the average particle diameter is less than 0.05 μm, the filling rate of spherical fillers in the composition decreases, which may result in lower mechanical strength. On the other hand, if the average particle diameter exceeds 5 μm, the surface area of ​​the spherical filler decreases, and there is a risk that a cured product of the photocurable resin composition for orthodontic appliances with high mechanical strength cannot be obtained.

[0091] The inorganic filler may be pre-treated with a known surface treatment agent, such as a silane coupling agent, as necessary, in order to adjust the fluidity of the photocurable orthodontic resin composition. Examples of such surface treatment agents include vinyltrimethoxysilane, vinyltriethoxysilane, vinyltrichlorosilane, vinyltri(β-methoxyethoxy)silane, γ-methacryloyloxypropyltrimethoxysilane, 8-methacryloyloxyoctyltrimethoxysilane, 11-methacryloyloxyundecyltrimethoxysilane, γ-glycidoxypropyltrimethoxysilane, γ-mercaptopropyltrimethoxysilane, and γ-aminopropyltriethoxysilane.

[0092] The surface treatment method can be any known method without particular limitation. For example, it can be a method of spraying the surface treatment agent onto the inorganic filler while vigorously stirring it, a method of dispersing or dissolving the inorganic filler and the surface treatment agent in a suitable solvent and then removing the solvent, or a method of hydrolyzing the alkoxy groups of the surface treatment agent with an acid catalyst in an aqueous solution to convert them to silanol groups, attaching them to the inorganic filler surface in the aqueous solution, and then removing the water. In any of these methods, the reaction between the inorganic filler surface and the surface treatment agent can be completed and the surface treatment performed by heating in the range of 50 to 150°C. The amount of surface treatment is not particularly limited. For example, 1 to 10 parts by mass of the surface treatment agent can be used per 100 parts by mass of the inorganic filler before treatment.

[0093] The organic-inorganic composite filler used in the present invention is obtained by pre-adding a polymerizable monomer to the above-mentioned inorganic filler, forming a paste, polymerizing it, and then pulverizing it. As the organic-inorganic composite filler, for example, TMPT filler (a mixture of trimethylolpropane methacrylate and silica filler that has been polymerized and then pulverized) can be used. The shape of the organic-inorganic composite filler is not particularly limited, and the particle size of the filler can be appropriately selected and used. From the viewpoint of handling properties and mechanical strength of the resulting composition, the average particle size of the organic-inorganic composite filler is preferably 0.001 to 50 μm, and more preferably 0.001 to 10 μm.

[0094] In this specification, the average particle size of the filler can be determined by laser diffraction scattering or electron microscopy observation of the particles. Specifically, laser diffraction scattering is convenient for measuring the particle size of particles 0.1 μm or larger, while electron microscopy observation is convenient for measuring the particle size of ultrafine particles smaller than 0.1 μm. 0.1 μm is the value measured by laser diffraction scattering.

[0095] Specifically, the laser diffraction scattering method can be used, for example, with a laser diffraction particle size distribution analyzer (SALD-2300: manufactured by Shimadzu Corporation), to measure particle size distribution by volume using a 0.2% sodium hexametaphosphate aqueous solution as the dispersion medium.

[0096] Specifically, electron microscopy observation can be performed by taking an electron microscope (Hitachi, Ltd., S-4000 model) photograph of particles, and then measuring the particle diameter of the particles (200 or more) observed within the unit field of view of that photograph using image analysis-based particle size distribution measurement software (Mac-View (Mountec Co., Ltd.)). In this case, the particle diameter is determined as the arithmetic mean of the longest and shortest lengths of the particles, and the average primary particle diameter is calculated from the number of particles and their respective particle diameters.

[0097] In the present invention, it is preferable to use a mixture or combination of two or more fillers having different materials, particle size distributions, and morphologies. By combining two or more fillers, the fillers are densely packed, and the number of interaction points between the fillers and polymerizable monomers, or between the fillers themselves, increases. Depending on the type of filler, the fluidity of the paste can be controlled by the presence or absence of shear force. In particular, from the viewpoint of the handling properties and paste properties of the photocurable orthodontic resin composition of the present invention, the filler (C) is preferably a combination of (I) a filler (C-1) with an average particle diameter of 1 nm or more and less than 0.1 μm and a filler (C-2) with an average particle diameter of 0.1 μm or more and 1 μm or less, a combination of (II) a filler (C-1) with an average particle diameter of 1 nm or more and less than 0.1 μm and a filler (C-3) with an average particle diameter of more than 1 μm and 10 μm or less, and a filler (C-1) with an average particle diameter of 1 nm or more and less than 0.1 μm. A combination of filler (C-2) with an average particle diameter of 0.1 μm or more and 1 μm or less (C-2) and filler (C-3) with an average particle diameter of more than 1 μm and 10 μm or less (C-3) (III), and a combination of fillers (C-2) with an average particle diameter of 0.1 μm or more and 1 μm or less (IV) are preferred. Among these combinations, (I), (II), and (III) are more preferred, with (I) and (II) being even more preferred, in terms of superior operability in clinical operations related to the formation of dental attachments for aligner orthodontics and the bonding of brackets. The combination of fillers (C-2) with an average particle diameter of 0.1 μm or more and 1 μm or less (IV) refers to an embodiment that includes two types of fillers (C-2) with different average particle diameters of 0.1 μm or more and 1 μm or less. The average particle diameter of filler (C-1) is preferably 1 nm or more and 90 nm or less, more preferably 2 nm or more and 80 nm or less, and even more preferably 3 nm or more and 70 nm or less. The average particle size of filler (C-2) is preferably 0.1 μm or more and 0.9 μm or less, more preferably 0.15 μm or more and 0.85 μm or less, and even more preferably 0.2 μm or more and 0.8 μm or less. The average particle size of filler (C-3) is preferably 1.2 μm or more and 9 μm or less, more preferably 1.5 μm or more and 8 μm or less, and even more preferably 2.0 μm or more and 7 μm or less.Furthermore, with the above combinations, different types of fillers (C) may be included in each particle size. In addition, particles other than fillers may be unintentionally included as impurities, as long as they do not impair the effects of the present invention.

[0098] The content of filler (C) is not particularly limited, but from the viewpoint of dischargeability and shapeability, it is preferably 50 to 700 parts by mass, more preferably 100 to 600 parts by mass, and even more preferably 125 to 400 parts by mass, per 100 parts by mass of polymerizable monomer (A) of the photocurable orthodontic resin composition. In one preferred embodiment, there is a photocurable orthodontic resin composition in which the content of filler (C) is 150 to 350 parts by mass per 100 parts by mass of polymerizable monomer (A) of the photocurable orthodontic resin composition. Furthermore, in another preferred embodiment, there is a photocurable orthodontic resin composition in which filler (C) contains filler (C-1) with an average particle size of 1 nm or more and less than 0.1 μm. In this preferred embodiment, the content of filler (C-1) is such that the shear viscosity ratio (η r The value of can be increased, and the operability in clinical procedures related to the formation of dental attachments for aligner orthodontics and the bonding of brackets is improved. Therefore, the amount is preferably 1 to 100 parts by mass, more preferably 2 to 80 parts by mass, and even more preferably 5 to 70 parts by mass per 100 parts by mass of polymerizable monomer (A).

[0099] One preferred embodiment (X-1) contains a polymerizable monomer (A), a photopolymerization initiator (B), and a filler (C), and is measured using a rotational viscoelasticity analyzer at 25°C and a shear rate of 10s. -1 The viscosity measured is 1 to 1000 Pa·s, and the shear viscosity ratio (η) is expressed by formula (1) above. rAn example of a photocurable resin composition for orthodontic appliances is one in which the ratio of fillers (C) is 10 or more, and the filler (C) comprises a combination (I) of filler (C-1) having an average particle diameter of 1 nm or more and less than 0.1 μm, and filler (C-2) having an average particle diameter of 0.1 μm or more and 1 μm or less, and the content of filler (C-2) is 500 to 10,000 parts by mass per 100 parts by mass of filler (C-1). In the above embodiment (X-1), the content of filler (C-2) is the shear viscosity ratio (η r The value of ) can be increased, and the operability in clinical operations related to the formation of dental attachments for aligner orthodontics and the bonding of brackets can be improved, so the amount of filler (C-1) is preferably 1000 parts by mass or more, more preferably 1200 parts by mass or more, and even more preferably 1500 parts by mass or more, per 100 parts by mass. In the above embodiment (X-1), the amount of filler (C-2) is the shear viscosity ratio (η r The value of ) can be increased, and the operability in clinical operations related to the formation of dental attachments for aligner orthodontics and the bonding of brackets is superior, so the amount of filler (C-1) is preferably 7000 parts by mass or less, more preferably 5000 parts by mass or less, and even more preferably 4000 parts by mass or less, per 100 parts by mass.

[0100] One preferred embodiment (X-2) contains a polymerizable monomer (A), a photopolymerization initiator (B), and a filler (C), with the shear rate being 10 s. -1 The viscosity measured is 1 to 1000 Pa·s, and the shear viscosity ratio (η) is expressed by formula (1) above. r An example of a photocurable resin composition for orthodontic appliances is one in which the shear viscosity ratio (η) is 10 or more, and the filler (C) comprises a combination (II) of filler (C-1) having an average particle diameter of 1 nm or more and less than 0.1 μm, and filler (C-3) having an average particle diameter of more than 1 μm and 10 μm or less, and the content of filler (C-3) is 500 to 10,000 parts by mass per 100 parts by mass of filler (C-1). In the above embodiment (X-2), the content of filler (C-3) is the shear viscosity ratio (η) rThe value of ) can be increased, and the operability in clinical operations related to the formation of dental attachments for aligner orthodontics and the bonding of brackets can be improved, so the amount of filler (C-1) is preferably 1000 parts by mass or more, more preferably 1200 parts by mass or more, and even more preferably 1500 parts by mass or more, per 100 parts by mass. In the above embodiment (X-2), the amount of filler (C-3) is the shear viscosity ratio (η r The value of ) can be increased, and the operability in clinical operations related to the formation of dental attachments for aligner orthodontics and the bonding of brackets is superior, so the amount of filler (C-1) is preferably 7000 parts by mass or less, more preferably 5000 parts by mass or less, and even more preferably 4000 parts by mass or less, per 100 parts by mass.

[0101] One preferred embodiment (X-3) contains a polymerizable monomer (A), a photopolymerization initiator (B), and a filler (C), with a shear rate of 10s. -1 The viscosity measured is 1 to 1000 Pa·s, and the shear viscosity ratio (η) is expressed by formula (1) above. r An example of a photocurable resin composition for orthodontic appliances is one in which the ratio of fillers (C) is 10 or more, and the filler (C) includes a combination (III) of filler (C-1) with an average particle diameter of 1 nm or more and less than 0.1 μm, filler (C-2) with an average particle diameter of 0.1 μm or more and 1 μm or less, and filler (C-3) with an average particle diameter of more than 1 μm and 10 μm or less, and the content of filler (C-3) is 110 to 10000 parts by mass per 100 parts by mass of the total content of fillers (C-1) and fillers (C-2). In the above embodiment (X-3), the content of filler (C-3) is the shear viscosity ratio (η r The value of ) can be increased, and the operability in clinical operations related to the formation of dental attachments for aligner orthodontics and the bonding of brackets can be improved, so the total content of filler (C-1) and filler (C-2) can be 300 parts by mass or more, more preferably 500 parts by mass or more, and even more preferably 1000 parts by mass or more. In the above embodiment (X-3), the content of filler (C-3) is the shear viscosity ratio (η rThe value of ) can be increased, and the operability in clinical procedures related to the formation of dental attachments for aligner orthodontics and the bonding of brackets is superior. Therefore, the total content of filler (C-1) and filler (C-2) can be increased to 7,000 parts by mass or less, more preferably 5,000 parts by mass or less, and even more preferably 4,000 parts by mass or less.

[0102] One preferred embodiment (X-4) contains a polymerizable monomer (A), a photopolymerization initiator (B), and a filler (C), with a shear rate of 10s. -1 The viscosity measured is 1 to 1000 Pa·s, and the shear viscosity ratio (η) is expressed by formula (1) above. r Examples of photocurable orthodontic resin compositions include one in which the ratio (η) is 10 or more, and the filler (C) is a combination (IV) of fillers (C-2) having an average particle diameter of 0.1 μm or more and 1 μm or less. In the above embodiment (X-4), the content of filler (C-2L) having a larger average particle diameter is 110 to 10000 parts by mass relative to the content of filler (C-2S) having a smaller average particle diameter than the other. In the above embodiment (X-4), the content of filler (C-2L) having a larger average particle diameter is the shear viscosity ratio (η) r The value of can be increased, and the operability in clinical operations related to the formation of dental attachments for aligner orthodontics and the bonding of brackets can be improved, so the content of filler with a smaller average particle size (C-2S) is preferably 300 parts by mass or more, more preferably 500 parts by mass or more, and even more preferably 1000 parts by mass or more, per 100 parts by mass. In the above embodiment (X-4), the content of filler with a larger average particle size (C-2L) is such that the shear viscosity ratio (η) can be increased. r The value of ) can be increased, and the operability in clinical procedures related to the formation of dental attachments for aligner orthodontics and the bonding of brackets is superior. Therefore, the content of filler (C-2S) with a smaller average particle size is preferably 7,000 parts by mass or less, more preferably 5,000 parts by mass or less, and even more preferably 4,000 parts by mass or less, per 100 parts by mass.

[0103] In any of the preferred embodiments (X-1) to (X-4) described above, the type and content of each component can be appropriately changed based on the description herein, and any component can be added, deleted, or otherwise modified. Furthermore, in any of the embodiments described above, the composition of each composition and the values ​​of each property of the cured product (flexural strength, flexural modulus, compressive strength, etc.) can be appropriately changed and combined. For example, in the cured product of the photocurable resin composition for orthodontic appliances of embodiments (X-1) to (X-4), the flexural modulus may be 2.0 to 12.0 GPa. Also, in the cured product of the photocurable resin composition for orthodontic appliances of embodiments (X-1) to (X-4), the compressive strength may be 100 to 400 MPa.

[0104] The method for producing the photocurable resin composition for orthodontic appliances of the present invention is not particularly limited as long as it contains the polymerizable monomer (A-1), photopolymerization initiator (B), and filler (C), and the photocurable resin composition for orthodontic appliances of the present invention can be easily produced by methods known to those skilled in the art.

[0105] Polymerization accelerator (D) The photocurable resin composition for orthodontic appliances of the present invention may use a polymerization accelerator (D) together with a water-insoluble photopolymerization initiator (B-2) and / or a chemical polymerization initiator described later. Examples of polymerization accelerators (D) used in the present invention include amines, sulfinic acid and its salts, borate compounds, barbituric acid derivatives, triazine compounds, copper compounds, tin compounds, vanadium compounds, halogen compounds, aldehydes, thiol compounds, sulfites, bisulfites, and thiourea compounds.

[0106] The amines used as polymerization accelerators (D) can be divided into aliphatic amines and aromatic amines. Examples of aliphatic amines include primary aliphatic amines such as n-butylamine, n-hexylamine, and n-octylamine; secondary aliphatic amines such as diisopropylamine, dibutylamine, and N-methylethanolamine; and tertiary aliphatic amines such as N-methyldiethanolamine, N-ethyldiethanolamine, Nn-butyldiethanolamine, N-lauryldiethanolamine, 2-(dimethylamino)ethyl methacrylate, N-methyldiethanolamine dimethacrylate, N-ethyldiethanolamine dimethacrylate, triethanolamine monomethacrylate, triethanolamine dimethacrylate, triethanolamine trimethacrylate, triethanolamine, trimethylamine, triethylamine, and tributylamine. Among these, tertiary aliphatic amines are preferred from the viewpoint of curability and storage stability of the photocurable orthodontic resin composition, and among them, N-methyldiethanolamine and triethanolamine are more preferably used.

[0107] Furthermore, aromatic amines include, for example, N,N-bis(2-hydroxyethyl)-3,5-dimethylaniline, N,N-bis(2-hydroxyethyl)-p-toluidine, N,N-bis(2-hydroxyethyl)-3,4-dimethylaniline, N,N-bis(2-hydroxyethyl)-4-ethylaniline, N,N-bis(2-hydroxyethyl)-4-isopropylaniline, N,N-bis(2-hydroxyethyl)-4-t-butylaniline, N,N-bis(2-hydroxyethyl)-3,5-diisopropylaniline, N,N-bis(2-hydroxyethyl)-3,5-di-t-butylaniline, N,N-dimethylaniline, N,N-dimethyl-p-toluidine, N,N-dimethyl-m-toluidine, and N,N-diethyl-p - Examples include toluidine, N,N-dimethyl-3,5-dimethylaniline, N,N-dimethyl-3,4-dimethylaniline, N,N-dimethyl-4-ethylaniline, N,N-dimethyl-4-isopropylaniline, N,N-dimethyl-4-t-butylaniline, N,N-dimethyl-3,5-di-t-butylaniline, ethyl 4-(N,N-dimethylamino)benzoate, methyl 4-(N,N-dimethylamino)benzoate, propyl 4-(N,N-dimethylamino)benzoate, n-butoxyethyl 4-(N,N-dimethylamino)benzoate, 2-(methacryloyloxy)ethyl 4-(N,N-dimethylamino)benzoate, benzophenone, and butyl 4-(N,N-dimethylamino)benzoate. Among these, at least one selected from the group consisting of N,N-bis(2-hydroxyethyl)-p-toluidine, 4-(N,N-dimethylamino)ethyl benzoate, 4-(N,N-dimethylamino)n-butoxyethyl benzoate, and 4-(N,N-dimethylamino)benzophenone is preferably used from the viewpoint of providing excellent curability to the photocurable orthodontic resin composition.

[0108] Specific examples of sulfinic acids and their salts, borate compounds, barbituric acid derivatives, triazine compounds, copper compounds, tin compounds, vanadium compounds, halogen compounds, aldehydes, thiol compounds, sulfites, bisulfites, and thiourea compounds are those described in International Publication No. 2008 / 087977.

[0109] The polymerization accelerator (D) described above may be blended alone or in combination of two or more types. The content of the polymerization accelerator (D) used in the present invention is not particularly limited, but from the viewpoint of the curability of the resulting photocurable orthodontic resin composition, it is preferably 0.001 to 30% by mass, more preferably 0.01 to 10% by mass, and even more preferably 0.1 to 5% by mass, relative to the total amount of polymerizable monomers (A) in the photocurable orthodontic resin composition. If the content of the polymerization accelerator (D) is less than 0.001% by mass, polymerization may not proceed sufficiently, which may lead to a decrease in adhesion, so it is more preferably 0.05% by mass or more. On the other hand, if the content of the polymerization accelerator (D) exceeds 30% by mass, sufficient adhesion may not be obtained, and furthermore, precipitation from the photocurable orthodontic resin composition may occur, so it is more preferably 20% by mass or less.

[0110] [Chemical polymerization initiator] The photocurable resin composition for orthodontic appliances of the present invention may further contain a chemical polymerization initiator, of which an organic peroxide is preferably used. The organic peroxide used as the chemical polymerization initiator is not particularly limited, and known ones can be used. Typical organic peroxides include, for example, ketone peroxides, hydroperoxides, diacyl peroxides, dialkyl peroxides, peroxyketals, peroxyesters, and peroxydicarbonates. Specific examples of these organic peroxides are those described in International Publication No. 2008 / 087977. The chemical polymerization initiator may be used alone or in combination of two or more.

[0111] [Fluoride ion-releasing substances] The photocurable resin composition for orthodontic appliances of the present invention may further contain a fluoride ion-releasing substance. By including a fluoride ion-releasing substance, a photocurable resin composition for orthodontic appliances that can impart acid resistance to tooth structure can be obtained. Examples of such fluoride ion-releasing substances include metallic fluorides such as sodium fluoride, potassium fluoride, sodium monofluorophosphate, lithium fluoride, and ytterbium fluoride. The above fluoride ion-releasing substances may be included individually or in combination of two or more.

[0112] The photocurable resin composition for orthodontic appliances may contain polymers and prepolymers, as long as they do not interfere with the effects of the present invention. Examples of polymers include polyurethane resins, (meth)acrylic resins, silicone resins, polyethylene, low-density polyethylene, high-density polyethylene, polyolefin resins such as polypropylene, cellulose resins, polyamide resins, ethylene / vinyl acetate copolymers, ethylene / vinyl alcohol copolymers, ethylene / acrylic acid copolymers, polyethylene glycol, polypropylene glycol, polystyrene, nitrile rubber, polybutadiene, polyisoprene, and ethylene / α-olefin copolymers.

[0113] Furthermore, the photocurable orthodontic resin composition of the present invention may contain known additives within a range that does not degrade performance. Examples of such additives include polymerization inhibitors, antioxidants, colorants (pigments, dyes), ultraviolet absorbers, solvents such as water and organic solvents, and thickeners. One additive may be used alone, or two or more may be used in combination. In one embodiment, the content of solvent (e.g., water, organic solvent) in the photocurable orthodontic resin composition is preferably less than 1% by mass, more preferably less than 0.1% by mass, and even more preferably less than 0.01% by mass, based on the total amount of the photocurable orthodontic resin composition.

[0114] Examples of polymerization inhibitors include hydroquinone, hydroquinone monomethyl ether, dibutylhydroquinone, dibutylhydroquinone monomethyl ether, t-butylcatechol, 2-t-butyl-4,6-dimethylphenol, 2,6-di-t-butylphenol, and 3,5-di-t-butyl-4-hydroxytoluene. The polymerization inhibitor content is preferably 0.001 to 1.0% by mass relative to the total amount of polymerizable monomers (A) in the photocurable orthodontic resin composition.

[0115] The light-curable resin composition for orthodontic appliances has excellent paste properties that balance fluidity and moldability, and its cured product has adhesive and removable properties to tooth structure, making it suitable for use in orthodontic appliances, particularly dental attachments for aligner orthodontics and adhesives for orthodontic brackets.

[0116] The following is an example of the composition ratio of a resin composition suitable for dental attachments and adhesives for orthodontic brackets. The photocurable resin composition for orthodontic appliances preferably contains, per 100 parts by mass of polymerizable monomer (A), 1 to 50 parts by mass of polymerizable monomer (A-1) having an acidic group, 50 to 99 parts by mass of polymerizable monomer (A-2) not having an acidic group, 0.05 to 15 parts by mass of photopolymerization initiator (B), 50 to 500 parts by mass of filler (C), and 0.001 to 30 parts by mass of polymerization accelerator (D), and per 100 parts by mass of polymerizable monomer (A), 2.5 to 40 parts by mass of polymerizable monomer (A-1) having an acidic group, and polymerizable monomer ( It is more preferable to include 60 to 95 parts by mass of A-2), 0.1 to 5 parts by mass of photopolymerization initiator (B), 100 to 400 parts by mass of filler (C), and 0.01 to 10 parts by mass of polymerization accelerator (D). It is even more preferable to include 5 to 30 parts by mass of polymerizable monomer (A-1) having an acidic group, 70 to 90 parts by mass of polymerizable monomer (A-2) not having an acidic group, 0.15 to 2.5 parts by mass of photopolymerization initiator (B), 150 to 300 parts by mass of filler (C), and 0.1 to 5 parts by mass of polymerization accelerator (D) per 100 parts by mass of total polymerizable monomer (A).

[0117] The material type of the photocurable resin composition for orthodontic appliances of the present invention is not particularly limited, and for example, it may be a two-paste type, but from the viewpoint of operability, it is preferable that it be a one-component type (one-paste type) in which all components are pre-mixed. The photocurable resin composition for orthodontic appliances of the present invention is preferably used by being filled into a cylindrical syringe container. The size of the cylindrical part of the syringe container is preferably 10 cm in length and 15 mm or less in inner diameter, and more preferably 7.5 cm in length and 10 mm or less in inner diameter. Furthermore, to improve handling, it may be used with a nozzle attached to the tip of the syringe. The size of the nozzle is preferably 25 mm in length and 1.5 mm or less in inner diameter of the opening, and more preferably 20 mm in length and 0.75 mm or less in inner diameter of the opening.

[0118] In one embodiment, the material contains a polymerizable monomer (A), a photopolymerization initiator (B), and a filler (C), and is measured using a rotational viscoelasticity measuring device at 25°C and a shear rate of 10s. -1 The viscosity measured is 1 to 1000 Pa·s, and the shear viscosity ratio (η) is expressed by the above formula (1). r One example is the use of a photocurable orthodontic resin composition having a coefficient of 10 or higher. The use may be for forming dental attachments or for bonding brackets. The use may be for fixing orthodontic aligners or for fixing brackets. The use may be on the surface of teeth. The use may be non-therapeutic. Another embodiment is the use of the photocurable orthodontic resin composition for orthodontic treatment. Yet another embodiment is the use of the photocurable orthodontic resin composition for the treatment of dental diseases. Examples of dental diseases include jaw deformities; malocclusion; and congenital diseases (e.g., cleft lip and palate, cleidocranial dysplasia, Pierre Robin syndrome, branchial arch syndrome, etc.).

[0119] Another embodiment involves using a photocurable orthodontic resin composition on the surface of a tooth to form a dental attachment or to bond a bracket, The aforementioned photocurable resin composition for orthodontic appliances contains a polymerizable monomer (A), a photopolymerization initiator (B), and a filler (C), and is measured using a rotational viscoelasticity measuring device at 25°C and a shear rate of 10s. -1 The viscosity measured is 1 to 1000 Pa·s, and the shear viscosity ratio (η) is expressed by the above formula (1). r One example is a method in which the ratio is 10 or more. Another embodiment is a method for manufacturing a dental attachment on the surface of a tooth, wherein the dental attachment is a cured product of a photocurable orthodontic resin composition, and the photocurable orthodontic resin composition contains a polymerizable monomer (A), a photopolymerization initiator (B), and a filler (C), and is measured using a rotary viscoelasticity measuring device at 25°C and a shear rate of 10s. -1 The viscosity measured is 1 to 1000 Pa·s, and the shear viscosity ratio (η) is expressed by the above formula (1). r A manufacturing method is provided in which the ratio is 10 or more. The method may also involve using a photocurable orthodontic resin composition on the surface of a tooth to fix an orthodontic aligner or a bracket. [Examples]

[0120] The present invention will be described in detail below with reference to examples and comparative examples, but the present invention is not limited to these examples. In the examples, parts refer to parts by mass unless otherwise specified.

[0121] Next, the components of the photocurable resin compositions for orthodontic appliances in the examples and comparative examples are listed below, along with their abbreviations.

[0122] [Polymerizable monomer with acidic group (A-1)] MDP:10-Methacryloyloxydecyldihydrogenphosphate

[0123] [Polymerizable monomer without acidic groups (A-2)] Bis-GMA:2,2-Bis[4-(3-methacryloyloxy-2-hydroxypropoxy)phenyl]propane D-2.6E: 2,2-Bis(4-methacryloyloxypolyethoxyphenyl)propane (average number of moles of ethoxy groups added: 2.6) 3G: Triethylene glycol dimethacrylate DD:1,10-Decanediol dimethacrylate MAEA: N-methacryloyloxyethylacrylamide

[0124] [Photopolymerization initiator (B)] • Water-soluble photopolymerization initiator (B-1) Li-TPO: Lithium phenyl(2,4,6-trimethylbenzoyl)phosphinate • Non-water-soluble photopolymerization initiator (B-2) CQ:dl-Camphorquinone BAPO: Bis(2,4,6-trimethylbenzoyl)phenylphosphine oxide

[0125] [Filler (C)] Filler 1: Ultrafine particle silica "Aerosil® R 972" manufactured by Nippon Aerosil Co., Ltd., average particle size: 16 nm Filler 2: Silane-treated silica 100 g of OX50 (manufactured by Nippon Aerosil Co., Ltd., ultrafine particle silica "Aerosil® OX50", average particle size: 0.04 μm), 7 g of γ-methacryloyloxypropyltrimethoxysilane, and 200 mL of 0.3% by mass aqueous acetic acid solution were placed in a three-necked flask and stirred at room temperature for 2 hours. After removing water by freeze-drying, the mixture was heat-treated at 80°C for 5 hours to obtain filler 2. Filler 3: Silane-treated silica powder Silica powder (manufactured by Nichitsu Co., Ltd., product name: High Silica) was crushed in a ball mill to obtain crushed silica powder. The average particle size of the obtained crushed silica powder was measured using a laser diffraction particle size distribution analyzer (manufactured by Shimadzu Corporation, model "SALD-2300") and was found to be 2.2 μm. 100 parts by mass of this crushed silica powder was surface-treated with 4 parts by mass of γ-methacryloyloxypropyltrimethoxysilane by a conventional method to obtain silane-treated silica powder. Filler 4: Silane-treated barium glass powder Barium glass (manufactured by ESTEC Co., Ltd., product code "E-3000") was crushed in a ball mill to obtain barium glass powder. The average particle size of the obtained barium glass powder was measured using a laser diffraction particle size distribution analyzer (manufactured by Shimadzu Corporation, model "SALD-2300") and was found to be 2.4 μm. 100 parts by mass of this barium glass powder was surface-treated with 3 parts by mass of γ-methacryloyloxypropyltrimethoxysilane by a conventional method to obtain silane-treated barium glass powder. Filler 5: Silane-treated barium glass powder 100 g of GM27884 NF180 grade (barium glass manufactured by SCHOTT, average particle size: 0.18 μm), 13 g of γ-methacryloyloxypropyltrimethoxysilane, and 200 mL of 0.3% by mass aqueous acetic acid solution were placed in a three-necked flask and stirred at room temperature for 2 hours. After removing water by freeze-drying, the mixture was heat-treated at 80°C for 5 hours to obtain filler 5. Filler 6: Silane-treated barium glass powder 100 g of 8235 UF0.7 grade (barium glass manufactured by SCHOTT, average particle size: 0.7 μm), 6 g of γ-methacryloyloxypropyltrimethoxysilane, and 200 mL of 0.3% by mass aqueous acetic acid solution were placed in a three-necked flask and stirred at room temperature for 2 hours. After removing water by freeze-drying, the mixture was heat-treated at 80°C for 5 hours to obtain filler 6. Filler 7: Silane-treated spherical silica-titania composite oxide powder 100 g of spherical silica-titania composite oxide (average particle size: 0.3 μm), 10 g of γ-methacryloyloxypropyltrimethoxysilane, and 200 mL of 0.3% by mass aqueous acetic acid solution were placed in a three-necked flask and stirred at room temperature for 2 hours. After removing water by freeze-drying, the mixture was heat-treated at 80°C for 5 hours to obtain filler 7. Ar380: Manufactured by Nippon Aerosil Co., Ltd., ultrafine particle silica "Aerosil 380", average particle size: 7nm

[0126] [Polymerization accelerator (D)] DABE: 4-(N,N-dimethylamino)ethyl benzoate

[0127] [Polymerization inhibitor] BHT: 3,5-di-t-butyl-4-hydroxytoluene

[0128] Examples 1-16 and Comparative Examples 1-4 (Preparation of photocurable resin compositions for orthodontic appliances) The raw materials shown in Tables 1 and 2 were mixed and kneaded at room temperature (23°C) in the dark to prepare a paste-like photocurable resin composition for orthodontic appliances, and its properties were investigated according to the methods of Test Examples 1 to 4 below. The results are shown in Tables 1 and 2.

[0129] Test Example 1: Shear viscosity - Shear viscosity ratio For each example and comparative example of the photocurable orthodontic resin composition, dynamic viscoelasticity was measured using a rotary rheometer (AR2000, manufactured by TA Instruments Co., Ltd.) with a plate diameter of 25 mm, a gap between plates of 0.50 mm, and a shear rate of 0.001 s. -1 and 10.0s -1 Under measurement conditions of 25°C, shear viscosity was measured (n=3), and the average value was calculated. Shear rate: 10.0 s -1 The viscosity measured must be in the range of 10 to 1000 Pa·s, more preferably in the range of 15 to 750 Pa·s, and even more preferably in the range of 20 to 500 Pa·s. Furthermore, the shear viscosity ratio (η) calculated from the results obtained from this measurement using Equation 1 is also required. r ) must be 10 or more, preferably 100 or more, and more preferably 200 or more.

[0130] Test Example 2: Compressive Strength Compressive strength was evaluated by a compression strength test. Specifically, the following procedure was performed: The prepared paste-like photocurable orthodontic resin composition was filled into a SUS mold (4 mm in diameter x 4 mm in thickness), and the top and bottom of the paste were pressed together with a glass slide. Next, the paste was cured by irradiating both sides of the paste for 10 seconds each through the glass slide using a dental visible light curing unit (PenCure 2000, manufactured by Morita Corporation). Then, the resulting cured material was immersed in distilled water and left in a constant temperature chamber set to 37°C for 24 hours. After that, a compression test was performed using a universal testing machine (Autograph AG-I 100kN, manufactured by Shimadzu Corporation) at a crosshead speed of 1 mm / min to measure the compressive strength (n=5), and the average value was calculated. In this measurement, when the compressive strength is between 100 and 400 MPa, the orthodontic efficiency and removal tend to be excellent.

[0131] Test Example 3: Bending Properties (Bending Modulus of Elasticity, Bending Strength) The bending modulus and bending strength were evaluated by bending tests in accordance with ISO 4049:2009. Specifically, the following was performed: The prepared paste-like photocurable orthodontic resin composition was filled into a SUS mold (2 mm long x 25 mm wide x 2 mm thick), and the top and bottom surfaces (2 mm x 25 mm) of the paste were pressed together with a glass slide. Next, the paste was cured by irradiating both sides of the paste at five points on each side for 10 seconds each using a dental visible light curing unit (PenCure 2000, manufactured by Morita Corporation) through the glass slide. The resulting cured material was subjected to a bending test using a universal testing machine (Autograph AG-I 100kN, manufactured by Shimadzu Corporation) with a support distance of 20 mm and a crosshead speed of 1 mm / min, and the three-point bending strength and bending modulus were measured (n=5), and the average value was calculated. In this measurement, when the flexural modulus is between 2.0 and 12.0 GPa and the flexural strength is between 60 MPa and 145 MPa, the material tends to exhibit superior straightening efficiency and removal capabilities.

[0132] Test Example 4: Shear bonding strength with tooth structure (uncut human tooth enamel) Samples were obtained by cleaning the labial surface of extracted human teeth with a toothbrush under running water. Tape was attached to the bottom of a 15-hole mold (Ultradent, φ35mm x height 25mm), and the sample teeth were fixed on top of it. Plaster was filled into the mold and left to stand for approximately 30 minutes to harden. The samples were removed from the mold, brushed with a toothbrush under running water to remove excess plaster and ensure a bonding surface (φ2.38mm or larger), and the bonding surface was washed with ultrasonic water for 5 minutes.

[0133] A tooth surface treatment material 1 (a mixture prepared by mixing concentrated phosphoric acid: 50 parts by mass, distilled water: 50 parts by mass, and Ar380: 5 parts by mass) was applied to the surface of the sample using a brush and left for 10 seconds. After that, the surface was washed with tap water for 10 seconds and dried with compressed air.

[0134] Next, a separately prepared φ2.38 mm CR filling mold (Bonding Mold Insert, manufactured by Ultradent) was attached to a dedicated instrument (Bonding Clamp, manufactured by Ultradent). Then, the CR filling mold attached to the dedicated instrument was lowered so that it was in close contact with the bonding surface of the sample treated with tooth surface treatment material 1, and the sample was fixed in place. Next, the photocurable orthodontic resin composition for each example and comparative example was thinly filled into the hole in the CR filling mold to a thickness of 1 mm or less. After that, the photocurable orthodontic resin composition was filled into the mold again (to about 2 / 3 of the mold, to a thickness of about 2 mm), and then irradiated with light for 10 seconds using a dental visible light curing unit "VALO" (manufactured by Ultradent Japan Co., Ltd.). The sample was removed from the mold and prepared as a test sample for adhesion testing, with a total of 10 samples prepared. Next, the adhesive test samples were immersed in distilled water and left in a constant temperature incubator set to 37°C for 24 hours. After removal, the shear adhesive strength was measured. The shear adhesive strength was measured by attaching the adhesive test sample to a dedicated holder (Test Base Clamp, manufactured by Ultradent), using a dedicated jig (Crosshead Assembly, manufactured by Ultradent) and a universal tester (Autograph AG-I 100kN, manufactured by Shimadzu Corporation), with the crosshead speed set to 1 mm / min. The adhesive strength value was the average of the measurements taken from 10 adhesive test samples. When the adhesive strength measured in this way is between 10 and 40 MPa, the dental attachment and bracket have excellent retention and removal properties.

[0135] Test Example 5 (Sagging) A circle with a diameter of 8 mm was drawn on a 30 mm x 30 mm square glass plate. 0.03 g of the paste-like photocurable orthodontic resin composition of each example and comparative example was placed inside the circle, and the glass plate was placed in a 37°C incubator with the mixing paper standing vertically for 3 minutes. The mixing paper was removed from the 37°C incubator, and the degree of paste dripping was visually observed and evaluated according to the following evaluation criteria (n=3). If even one sample did not meet a specific evaluation criterion, it was judged to not meet that specific evaluation criterion. A dripping score of 1 or 2 was considered acceptable. If the dripping score was 3 or 4, the photocurable orthodontic resin composition would drip when used on the tooth surface, making it impossible to fix the orthodontic attachment and orthodontic bracket in the appropriate position.

[0136] [Evaluation criteria for drooping] 1: The paste remains in the same state as when it was placed on the table, with almost no dripping. 2: The paste is dripping within the circumference of a circle with a major axis of 8 mm. 3: The paste is dripping down to the extent that it covers the circumference of a circle with a major axis of 8 mm. 4: The paste is dripping so much that it spills over the circumference of a circle with a major axis of 8 mm.

[0137] [Table 1]

[0138] [Table 2]

[0139] Tables 1 and 2 show that the photocurable orthodontic resin compositions in the examples have appropriate shear viscosity and shear viscosity ratio, resulting in excellent operability. They also exhibit appropriate compressive strength and moderate brittleness. Furthermore, they have appropriate flexural modulus, leading to excellent orthodontic efficiency and removal. Finally, they have appropriate adhesion to tooth structure, resulting in excellent retention and removal of attachments or brackets. On the other hand, in the comparative examples, the shear viscosity ratio of filler (C) was less than 10 due to specific mixing ratios or monomer content, and in some comparative examples, the sagging was 3 or higher, resulting in photocurable orthodontic resin compositions with poor operability. In the photocurable orthodontic resin compositions of Comparative Examples 1-3, the paste sagged during clinical procedures when attaching templates for forming dental attachments or after determining bracket positions, making it impossible to prevent the attachment or bracket from moving after positioning. Furthermore, the photocurable resin compositions for orthodontic appliances described in Comparative Examples 1, 2, and 4 have excessively high shear viscosity and insufficient fluidity, requiring significant force to spread the paste when positioning dental attachments or brackets. [Industrial applicability]

[0140] The photocurable resin composition for orthodontic appliances of the present invention can be suitably used as an adhesive for orthodontic attachments and orthodontic brackets.

Claims

1. It contains a polymerizable monomer (A), a photopolymerization initiator (B), and a filler (C), The polymerizable monomer (A) contains a polymerizable monomer having an acidic group (A-1) and a polymerizable monomer not having an acidic group (A-2), The polymerizable monomer (A-1) having an acidic group is a (meth)acrylate polymerizable monomer having a phosphate group, The content of the polymerizable monomer (A-1) having the acidic group is 1 to 50% by mass of the total amount of polymerizable monomer (A). The content of the polymerizable monomer (A-2) that does not have an acidic group is 50 to 99% by mass of the total amount of polymerizable monomer (A). The aforementioned photopolymerization initiator (B) consists solely of a water-insoluble photopolymerization initiator (B-2) having a solubility in water at 25°C of less than 10 g / L. The filler (C) includes at least one combination selected from the group consisting of: (I) a combination of a filler (C-1) with an average particle diameter of 1 nm or more and less than 0.1 μm and a filler (C-2) with an average particle diameter of 0.1 μm or more and 1 μm or less; (II) a combination of a filler (C-1) with an average particle diameter of 1 nm or more and less than 0.1 μm and a filler (C-3) with an average particle diameter greater than 1 μm and 10 μm or less; (III) a combination of a filler (C-1) with an average particle diameter of 1 nm or more and less than 0.1 μm and a filler (C-2) with an average particle diameter of 0.1 μm or more and 1 μm or less and a filler (C-3) with an average particle diameter greater than 1 μm and 10 μm or less; and (IV) two fillers (C-2) with an average particle diameter of 0.1 μm or more and 1 μm or less. In the case of the above combination (I), the content of filler (C-1) is 2 to 70 parts by mass per 100 parts by mass of polymerizable monomer (A), and the content of filler (C-2) is 1,000 to 4,000 parts by mass per 100 parts by mass of filler (C-1). In the case of the above combination (II), the content of filler (C-1) is 2 to 70 parts by mass per 100 parts by mass of polymerizable monomer (A), and the content of filler (C-3) is 1,000 to 4,000 parts by mass per 100 parts by mass of filler (C-1). In the case of the above combination (III), the content of filler (C-1) is 2 to 70 parts by mass per 100 parts by mass of polymerizable monomer (A), and the content of filler (C-3) is 1,000 to 4,000 parts by mass per 100 parts by mass of the total content of filler (C-1) and filler (C-2). In the case of the above combination (IV), if we define the one with a relatively small average particle diameter as (C-2S) and the one with a larger average particle diameter as (C-2L), then the content of the filler with a larger average particle diameter (C-2L) relative to 100 parts by mass of the filler with a smaller average particle diameter (C-2S) is 110 to 4000 parts by mass. Using a rotary viscoelasticity measuring device, at 25°C and a shear rate of 10 s, -1 The viscosity measured is 10 to 1000 Pa·s, and the shear viscosity ratio (η) is expressed by the following formula (1). r A photocurable resin composition for orthodontic appliances, wherein the ratio of ) is 10 or more. [Math 1]

2. The photocurable resin composition for orthodontic appliances according to claim 1, wherein the polymerizable monomer (A-2) without acidic groups contains a hydrophobic polymerizable monomer (A-2b) without acidic groups and, if necessary, a hydrophilic polymerizable monomer (A-2c) without acidic groups, and the mass ratio of the hydrophilic polymerizable monomer (A-2c) without acidic groups to the hydrophobic polymerizable monomer (A-2b) without acidic groups is hydrophilic polymerizable monomer (A-2c) without acidic groups: hydrophobic polymerizable monomer (A-2b) without acidic groups = 0:10 to 2:

1.

3. The photocurable resin composition for orthodontic appliances according to claim 1 or 2, wherein the polymerizable monomer (A-2) that does not have an acidic group contains an asymmetric acrylamide / methacrylate ester compound (A-2a) represented by the following general formula (1). 【Chemistry 1】 [wherein, Z is a linear or branched aliphatic group or aromatic group of C 1 to C 8 which may have a substituent, and the aliphatic group is interrupted by at least one linking group selected from the group consisting of -O-, -S-, -CO-, -CO-O-, -O-CO-, -NR 1 -, -CO-NR 1 -, -NR 1 -CO-, -CO-O-NR 1 -, -O-CO-NR 1 - and -NR 1 -CO-NR 1 - may be interrupted. R 1 represents a hydrogen atom or a linear or branched aliphatic group of C 1 to C 8 which may have a substituent. ]

4. Z may have substituents. 1 ~C 4 The photocurable resin composition for orthodontic appliances according to claim 3, wherein the aliphatic group is linear or branched.

5. Z may have substituents. 1 ~C 4 The photocurable resin composition for orthodontic appliances according to claim 3 or 4, wherein the alkylene group is linear or branched.

6. The photocurable resin composition for orthodontic appliances according to any one of claims 1 to 5, wherein the filler (C) comprises the combination (I) or the combination (II).

7. The photocurable resin composition for orthodontic appliances according to claim 2, wherein the hydrophobic polymerizable monomer (A-2b) that does not have an acidic group comprises a hydrophobic polymerizable monomer having a hydroxyl group.

8. The photocurable resin composition for orthodontic appliances according to any one of claims 1 to 7, wherein the cured product of the photocurable resin composition for orthodontic appliances has a flexural strength of 60 MPa or more and less than 145 MPa.

9. The photocurable resin composition for orthodontic appliances according to any one of claims 1 to 8, wherein the compressive strength of the cured product of the photocurable resin composition for orthodontic appliances is 250 to 400 MPa.

10. The photocurable resin composition for orthodontic appliances according to any one of claims 1 to 9, wherein the photocurable resin composition for orthodontic appliances is a single-component type.

11. An orthodontic attachment comprising a cured product of a photocurable resin composition for orthodontic appliances according to any one of claims 1 to 10.

12. An adhesive for orthodontic brackets comprising the photocurable resin composition for orthodontic appliances described in any one of claims 1 to 10.

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