Hardenable composition for dental restoration

Abstract

The present invention provides a curable composition for dental restoration which gives cured objects that have high mechanical strength and toughness and are excellent in terms of water resistance and gloss retention, a dental composite resin comprising the curable composition for dental restoration, and a dental mill blank comprising a cured object formed from the curable composition for dental restoration. The present invention relates to a curable composition for dental restoration comprising: a (meth)acrylic acid ester compound (A) which has at least one polymer structure selected from the group consisting of polycarbonates, polyarylates, and aromatic polysulfones and in which a terminal hydroxy residue derived from a repeating unit serving as a component of the polymer structure has been directly (meth)acryloylated; a (meth)acrylic acid ester compound (B) having two or more (meth)acryloyloxy groups (the compound (B) is not the (meth)acrylic acid ester compound (A)); an inorganic filler (C) having an average primary-particle diameter of 0.01-5 μm; and a polymerization initiator (D).

Description

[Technical Field]

[0001] The present invention relates to a dental material that can replace part or all of natural teeth in the field of dentistry, particularly a dental restorative hardenable composition that is suitably used as a dental composite resin, a dental composite resin comprising the dental restorative hardenable composition, and a dental mill blank comprising a cured product of the dental restorative hardenable composition. [Background technology]

[0002] A dental restorative hardenable composition comprising a polymerizable monomer, an inorganic filler, a polymerization initiator, etc., is called a dental composite resin, and is the most widely used dental material today for repairing missing teeth and caries. The hardened product of a dental composite resin after polymerization and hardening must have sufficient mechanical strength to replace natural teeth, water resistance to withstand long-term intraoral restoration, and polishability to achieve a gloss equivalent to that of natural teeth. Furthermore, the paste state before polymerization and hardening must have suitable operability for filling cavities using dental instruments, etc.

[0003] For example, a technology has been proposed in which polycarbonate dimethacrylate represented by the following formula (III) is blended with the aim of achieving excellent paste operability and abrasion resistance of the cured product (Patent Document 1). Also, a photocurable resin composition has been proposed that contains a polycarbonate having a molecular weight of 200 to 10,000 and containing at least two (meth)acrylate groups per molecule (Patent Document 2). By including this polycarbonate, the casting clasp can be manufactured with excellent operability, excellent surface properties, and reduced deformation. [ka] [In the formula, A is an alkylene group having 1 to 6 carbon atoms, R is an alkylene group having 2 to 5 carbon atoms and at least two carbon atoms in its main chain, and n is an integer of 1 to 4.]

[0004] Dental mill blanks are materials used to fabricate dental prostheses such as inlays and crowns using a CAD / CAM system, which involves computer-aided design and milling. Demand for these materials has been rapidly increasing in recent years. Dental mill blanks are supplied as blocks of appropriate size, such as rectangular parallelepipeds, cylinders, or discs, which are then placed in a milling machine and milled to produce restorations in the shape of a crown or arch of teeth. Various materials have been proposed for dental mill blanks, including glass ceramics, zirconia, titanium, acrylic resins, and composites containing polymer resins and inorganic fillers. Dental mill blanks also require sufficient mechanical strength to replace natural teeth, water resistance to withstand long-term intraoral restorations, and polishability to achieve a gloss equivalent to that of natural teeth.

[0005] For example, a method for producing a dental mill blank has been described in which, in order to achieve mechanical strength and polishing properties, an inorganic filler is press-molded to obtain a molded body, and then the molded body is immersed in a polymerizable monomer and polymerized by heating (Patent Document 3). This production method makes it possible to pack nanoparticles at a high density, and a dental mill blank with excellent mechanical strength and polishing properties can be obtained. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] Japanese Patent Application Publication No. 62-226907 [Patent Document 2] Japanese Patent Application Publication No. 5-78435 [Patent Document 3] International Publication No. 2014 / 021343 Summary of the Invention [Problem to be solved by the invention]

[0007] However, as a result of investigations by the present inventors, it was found that the dental curable composition disclosed in Patent Document 1 has problems such as low mechanical strength and water resistance. In addition, there is also room for improvement in the operability of the paste.

[0008] Furthermore, the dental curable composition disclosed in Patent Document 2 does not contain an inorganic filler, and therefore has problems in that the paste has very poor workability when used as a dental composite resin, and the resulting cured product has poor smoothness durability.

[0009] Furthermore, the dental mill blank disclosed in Patent Document 3 had room for further improvement in toughness (fracture energy), mechanical strength, and water resistance. Also, for example, in the application of dental composite resins, it was known that mechanical strength (particularly bending strength) increases with increasing content of inorganic filler, but toughness decreases with increasing blending amount of inorganic filler, and is excellent when the content of inorganic filler is low, so that mechanical strength (particularly bending strength) and toughness are in a trade-off relationship (Dental Materials and Instruments Vol. 7 No. 5 756-768, 1988).

[0010] The present invention has been made to solve the above-mentioned problems of the prior art, and aims to provide a dental restorative hardenable composition that has high mechanical strength and toughness in the cured product and excellent water resistance and smoothness durability. Another object of the present invention is to provide a dental restorative hardenable composition that also has excellent paste workability, and a dental composite resin comprising the dental restorative hardenable composition. A further object of the present invention is to provide a dental mill blank that has excellent aesthetics due to minimal bubbles. [Means for solving the problem]

[0011] As a result of extensive research to achieve the above-mentioned object, the present inventors have found that the above-mentioned problems can be solved by using a (meth)acrylic acid ester compound in which the terminal hydroxyl residues of the main chain of a polycarbonate structure, a polyarylate structure, or an aromatic polysulfone structure are directly (meth)acryloylated. Based on this finding, further research has led to the completion of the present invention.

[0012] That is, the present invention includes the following inventions. [1] A dental restorative curable composition comprising: a (meth)acrylic acid ester compound (A) having at least one polymer structure selected from the group consisting of polycarbonate, polyarylate, and aromatic polysulfone, in which a terminal hydroxyl residue derived from a repeating unit constituting the polymer structure is directly (meth)acryloylated; a (meth)acrylic acid ester compound (B) having two or more (meth)acryloyloxy groups (excluding the (meth)acrylic acid ester compound (A)); an inorganic filler (C) having an average primary particle size of 0.01 to 5 μm; and a polymerization initiator (D). [2] The dental restorative hardenable composition according to [1], wherein the polymer structure has a cyclic structure. [3] The dental restorative hardenable composition according to [1] or [2], wherein the polymer structure has three or more functional groups, each independently selected from the group consisting of a carbonate group, an ester group, and a sulfonyl group. [4] The dental restorative hardenable composition according to any one of [1] to [3], wherein the (meth)acrylic acid ester compound (A) has a number average molecular weight of 300 to 5,000. [5] The dental restorative hardenable composition according to any one of [1] to [4], wherein the content of the (meth)acrylic acid ester compound (A) is 1 to 40 mass% based on the total amount of polymerizable monomers. [6] The dental restorative hardenable composition according to any one of [1] to [5], further comprising at least one selected from the group consisting of a mono(meth)acrylic acid ester compound (E-1) represented by the following general formula (I) and a mono(meth)acrylic acid ester compound (E-2) represented by the following general formula (II): [ka] [ka] [In the formula, R 1 and R 2 are each independently a group represented by the following general formula (i) or a group represented by the following general formula (ii), and X is a divalent hydrocarbon group having 1 to 6 carbon atoms or an oxygen atom. [ka] [ka] (In the formula, R 3 and R 5 are each independently a divalent hydrocarbon group having 1 to 10 carbon atoms, and R 4 and R 6 are each independently a hydrogen atom or a methyl group, and k and l are each independently an integer of 0 to 6.)] [7] The hardenable composition for dental restoration according to [6], wherein X is an oxygen atom. [8] The dental restorative hardenable composition according to [6] or [7], wherein k and l are each independently 0 or 1. [9] The dental restorative hardenable composition according to any one of [1] to [8], wherein the content of the inorganic filler (C) is 50 to 95 mass % of the total amount of the dental restorative hardenable composition.

[10] The dental restorative hardenable composition according to any one of [1] to [9], wherein the polymerization initiator (D) contains a photopolymerization initiator.

[11] The dental restorative hardenable composition according to any one of [1] to

[10] , wherein the polymerization initiator (D) contains a thermal polymerization initiator.

[12] A dental composite resin comprising the dental restorative hardenable composition according to any one of [1] to

[11] .

[13] A dental mill blank comprising a cured product of the dental restorative hardenable composition according to any one of [1] to

[11] . [Effects of the Invention]

[0013] According to the present invention, there is provided a dental restorative hardenable composition which, when cured, has high mechanical strength and toughness, and is excellent in water resistance and smoothness durability. The dental restorative hardenable composition of the present invention also has excellent paste workability. Furthermore, the dental restorative hardenable composition of the present invention can suppress the generation of bubbles in the cured product, thereby resulting in excellent aesthetic appearance of the cured product. Furthermore, according to the present invention, there is provided a dental restorative hardenable composition which, when cured, has high mechanical strength and toughness, and is excellent in water resistance and smoothness durability, even when the content of inorganic filler is high (for example, 50 to 95% by mass of the total amount of the dental restorative hardenable composition). DETAILED DESCRIPTION OF THE INVENTION

[0014] The present invention will be described in detail below. In this specification, the upper and lower limits of the numerical ranges (contents of each component, values calculated from each component, and each physical property) can be appropriately combined. In addition, in this specification, the numerical values of each symbol in the formula can also be appropriately combined.

[0015] The dental restorative hardenable composition of the present invention comprises a specific (meth)acrylic acid ester compound (A) (hereinafter sometimes simply referred to as "(meth)acrylic acid ester compound (A)"), a (meth)acrylic acid ester compound (B) having two or more (meth)acryloyloxy groups per molecule, an inorganic filler (C) having an average primary particle size of 0.01 to 5 μm, and a polymerization initiator (D). In order to achieve the effects of the present invention, it is important that the (meth)acrylic acid ester compound (A) is a compound having at least one polymer structure selected from the group consisting of polycarbonate, polyarylate, and aromatic polysulfone, in which a terminal hydroxyl residue derived from a repeating unit constituting the polymer structure is directly (meth)acryloylated.

[0016] While the reason why the above-described configuration achieves the effects of the present invention is not entirely clear, the inventors speculate as follows. Dental restorative curable compositions generally contain an inorganic filler and a (meth)acrylic acid ester compound as a polymerizable monomer, and many of these compositions provide excellent mechanical strength, such as bending strength and elastic modulus, in the resulting cured product. However, polymers of (meth)acrylic acid ester compounds have low flexibility and are relatively brittle. Furthermore, the incorporation of an inorganic filler increases hardness and thus brittleness. This reduces the "fracture energy," which refers to the total energy required to break a cured dental restorative curable composition. This, in turn, reduces toughness, making the material more susceptible to fracture due to the energy applied during occlusion. Potential approaches to increasing the fracture energy (toughness) include reducing the amount of inorganic filler or substituting a more flexible organic filler. However, these approaches tend to result in sticky paste-like dental restorative curable compositions mixed with polymerizable monomers, which tend to adhere to dental instruments when filling a cavity with the dental restorative curable composition, resulting in poor operability. Furthermore, the cured product of the dental restorative hardenable composition has poor water resistance, resulting in a decline in physical properties due to water absorption. The factors that contribute to the compatibility of mechanical strength, such as bending strength, with toughness are presumably due to the excellent toughness of the polycarbonate, polyarylate, or aromatic polysulfone polymer structure constituting the (meth)acrylic acid ester compound (A). Furthermore, the direct (meth)acryloylation of terminal hydroxyl residues derived from the repeating units constituting the polymer structure leads to high-density crosslinking of the polymer structure during polymerization, thereby improving mechanical strength. Furthermore, the polymer structure also has excellent water resistance, and a highly crosslinked polymer obtained by polymerizing the (meth)acrylic acid ester compound (A) having this polymer structure is thought to have excellent water resistance. Furthermore, the absence of an extra spacer between the polymer structure and the methacryloyl group in the (meth)acrylic acid ester compound (A) allows for a low molecular weight and viscosity, presumably resulting in excellent workability of the dental restorative hardenable composition and suppressed bubble formation in the cured product.Furthermore, by using the (meth)acrylic acid ester compound (A), the dental restorative curable composition also has excellent smoothness durability.

[0017] The polymerizable monomer used in the present invention may be any known polymerizable monomer used in dental restorative hardenable compositions (such as dental composite resins) without any particular limitation, as long as a specific mass ratio is satisfied. However, radically polymerizable monomers are generally preferred. Specific examples of radically polymerizable monomers include esters of α-cyanoacrylic acid, (meth)acrylic acid, α-halogenated acrylic acid, crotonic acid, cinnamic acid, sorbic acid, maleic acid, itaconic acid, etc.; (meth)acrylamide-based polymerizable monomers such as (meth)acrylamide and (meth)acrylamide derivatives; vinyl esters; vinyl ethers; mono-N-vinyl derivatives; styrene derivatives, etc. Among these, one or more polymerizable monomers selected from the group consisting of (meth)acrylate-based polymerizable monomers and (meth)acrylamide-based polymerizable monomers are preferred, with (meth)acrylate-based polymerizable monomers being more preferred. The (meth)acrylate polymerizable monomer includes a (meth)acrylic acid ester compound (A) described below and a (meth)acrylic acid ester compound (B) having two or more (meth)acryloyloxy groups. In the present invention, the term "(meth)acrylic" is used to encompass both methacrylic and acrylic, the term "(meth)acrylate" is used to encompass both methacrylate and acrylate, and the term "(meth)acryloyloxy group" is used to encompass both methacryloyloxy group and acryloyloxy group.

[0018] [(Meth)acrylic acid ester compound (A)] The (meth)acrylic acid ester compound (A) is a compound having, in one molecule, at least one polymer structure selected from the group consisting of polycarbonate, polyarylate, and aromatic polysulfone, in which a terminal hydroxyl residue derived from a repeating unit constituting the polymer structure is directly (meth)acryloylated. As described above, in order to achieve the effects of the present invention, it is important that the compound has the polymer structure and in which a terminal hydroxyl residue derived from a repeating unit constituting the polymer structure is directly (meth)acryloylated. In contrast, in the prior art, for example, in the compound represented by formula (III) described in Patent Document 1, a spacer represented by "-OAO-" is present between the terminal hydroxyl group and the methacryloyl group in the polycarbonate, resulting in a relatively low density of the polycarbonate structure. In addition, the spacer itself is an alkylene group, and due to the flexible skeleton, the mechanical strength (flexural strength) is thought to be lower than that of the present invention. Furthermore, in the prior art, in addition to the low density of the polymer skeleton, the polymer is susceptible to water absorption due to the presence of alkylene groups and ether bonds or urethane bonds between the methacryloyl group and the hydroxyl residues at both ends derived from the repeating units constituting the polymer structure (for example, PCUMA in Synthesis Example 6 described below), and is therefore thought to have lower water resistance than the polymer of the present invention.

[0019] The specific structures of the polycarbonate, polyarylate, and aromatic polysulfone are not particularly limited. Examples of polycarbonates include polycarbonates derived from aliphatic diols having 2 to 30 carbon atoms, polycarbonates derived from aromatic ring diols having 2 to 30 carbon atoms, and polycarbonates derived from a combination of these diols. Examples of polyarylates include amorphous polyarylates such as polymers having ester groups derived from diols having 12 to 30 carbon atoms and bisphenol skeletons and dicarboxylic acids having 4 to 14 carbon atoms. Examples of aromatic polysulfones include polymers derived from diols having 2 to 30 carbon atoms and dihalides having sulfonyl groups having 2 to 30 carbon atoms. Examples of aromatic polysulfones include polysulfones having a repeating unit represented by the following formula (1), polyethersulfones having a repeating unit represented by the following formula (2), and polyphenylsulfones having a repeating unit represented by the following formula (3). -O-Ar-C(CH3)2-Ar-O-Ar-SO2-Ar- (1) -O-Ar-SO2-Ar- (2) -O-Ar-Ar-O-Ar-SO2-Ar- (3) (In the formula, Ar represents a disubstituted phenyl group (p-phenylene group) at the para position, and the degree of polymerization and molecular weight are not particularly limited.) Among these, the polycarbonate structure is preferred in that the cured product has excellent water resistance, toughness, smoothness durability, and operability. The (meth)acrylic acid ester compound (A) may be used alone or in combination of two or more.

[0020] The polymer structure of the (meth)acrylic acid ester compound (A) preferably contains a cyclic structure, which is a rigid skeleton, in order to provide excellent mechanical strength after curing. Examples of the cyclic structure include an alicyclic ring, an aromatic ring, and a heterocyclic ring.

[0021] Examples of the alicyclic ring include cyclopentane, cyclohexane, cycloheptane, dicyclodecane, tricyclodecane, adamantane, isobornyl, etc. Among these, tricyclodecane and isobornyl are more preferred.

[0022] Examples of aromatic rings include benzene, naphthalene, anthracene, biphenyl, benzophenone, phenyl ether, and bisphenol A. Among these, biphenyl, benzophenone, phenyl ether, and bisphenol A are more preferred.

[0023] Examples of heterocycles include heterocycles containing only nitrogen atoms as heteroatoms, such as triazine, carbazole, pyrrolidin, and piperidine; heterocycles containing only oxygen atoms as heteroatoms, such as tetrahydrofuran, oxane, dioxane, dioxolane, and isosorbide; heterocycles containing oxygen and nitrogen atoms as heteroatoms, such as morpholine; heterocycles containing only sulfur atoms as heteroatoms, such as tetrahydrothiophene and tetrahydrothiopyran; and heterocycles containing sulfur and nitrogen atoms as heteroatoms, such as thiazine and thiazole. Among these, triazine, isosorbide, and morpholine are more preferred.

[0024] Furthermore, in order to obtain a cured product with superior toughness, the polymer structure of the (meth)acrylic acid ester compound (A) preferably has three or more, more preferably four or more, and even more preferably five or more, functional groups of at least one type independently selected from the group consisting of carbonate groups, ester groups, and sulfonyl groups. The polymer structure may be, for example, a structure having two or more carbonate groups and one or more sulfonyl groups, a structure having three or more carbonate groups, a structure having three or more ester groups, or a structure having three or more sulfonyl groups.

[0025] The (meth)acrylic acid ester compound (A) contains the polymer structure, and the terminal hydroxyl residue derived from the repeating unit constituting the polymer structure is directly (meth)acryloylated. Here, "the terminal hydroxyl residue is directly (meth)acryloylated" refers to a state in which there is no other atom between the oxygen atom constituting the terminal hydroxyl residue derived from the repeating unit constituting the polymer structure and the carbon atom constituting the carbonyl group in the (meth)acryloyl group. The reaction of directly (meth)acryloylating the terminal hydroxyl residue can be carried out according to a known method and is not particularly limited.

[0026] The (meth)acrylic acid ester compound (A) is preferably a compound in which the polymer structure is not crosslinked within the molecule.

[0027] The number average molecular weight (Mn) of the (meth)acrylic acid ester compound (A) is not particularly limited, but is preferably 300 to 5000. From the viewpoints of excellent toughness of the cured product and keeping the viscosity of the entire polymerizable monomer low and improving the workability of the dental restorative curable composition, it is more preferably 400 to 3500, and even more preferably 500 to 2500. Note that the number average molecular weight (Mn) in the present invention means the number average molecular weight in terms of polystyrene determined by gel permeation chromatography (GPC), and can be measured by known methods, for example, by the method described in the Examples below.

[0028] The content of the (meth)acrylic acid ester compound (A) is not particularly limited, but is preferably 1 to 40% by mass based on the total amount of polymerizable monomers. From the viewpoint of superior mechanical strength and toughness, it is more preferably 3 to 35% by mass, and even more preferably 5 to 30% by mass. The content of the (meth)acrylic acid ester compound (A) in the dental restorative hardenable composition of the present invention is not particularly limited, but is preferably 0.1 to 20% by mass based on the total amount of the dental restorative hardenable composition. From the viewpoint of superior mechanical strength and toughness, it is more preferably 0.2 to 15% by mass, and even more preferably 0.5 to 10% by mass. When the content of the (meth)acrylic acid ester compound (A) is 0.1% by mass or more based on the total amount of the dental restorative hardenable composition, the toughness of the resulting cured product can be further improved. Furthermore, when the content of the (meth)acrylic acid ester compound (A) is 20% by mass or less based on the total amount of the dental restorative hardenable composition, the mechanical strength of the resulting cured product can be further improved.

[0029] [(Meth)acrylic acid ester compound (B) having two or more (meth)acryloyloxy groups] The (meth)acrylic acid ester compound (B) having two or more (meth)acryloyloxy groups in one molecule used in the present invention (hereinafter sometimes simply referred to as "(meth)acrylic acid ester compound (B)") is not particularly limited as long as it exhibits the effects of the present invention and is a known (meth)acrylic acid ester compound used in dental restorative hardenable compositions (such as dental composite resins). However, the (meth)acrylic acid ester compound (A) of the present invention is excluded. Specific examples of the (meth)acrylic acid ester compound (B) having two or more (meth)acryloyloxy groups are listed below. The (meth)acrylic acid ester compound (B) may be used alone or in combination of two or more. The (meth)acrylic acid ester compound (B) imparts mechanical strength to the cured product.

[0030] (i) Bifunctional (meth)acrylic acid ester compound For example, ethylene glycol di(meth)acrylate, triethylene glycol di(meth)acrylate, propylene glycol di(meth)acrylate, neopentyl glycol di(meth)acrylate, 1,6-hexanediol di(meth)acrylate, 1,10-decanediol di(meth)acrylate, 2,2-bis[4-[3-acryloyloxy-2-hydroxypropoxy]phenyl]propane, 2,2-bis[4-[3-methacryloyloxy-2-hydroxypropoxy]phenyl]propane (Bis-GMA), 2,2-bis[4-(meth)acryloyloxyethoxyphenyl]propane, 2,2-bis[4-(meth)acryloyloxypolyethoxyphenyl]propane, 1,2-bis Examples of such an alkyl acrylate include [3-(meth)acryloyloxy-2-hydroxypropoxy]ethane, pentaerythritol di(meth)acrylate, [2,2,4-trimethylhexamethylenebis(2-carbamoyloxyethyl)]dimethacrylate (UDMA), and 2,2,3,3,4,4-hexafluoro-1,5-pentyl di(meth)acrylate. Of these, triethylene glycol di(meth)acrylate, neopentyl glycol di(meth)acrylate, 1,6-hexanediol di(meth)acrylate, 1,10-decanediol di(meth)acrylate, Bis-GMA, 2,2-bis[4-methacryloyloxypolyethoxyphenyl]propane (average number of moles of ethoxy groups added: 2.6), and UDMA are preferred.

[0031] (ii) Tri- or higher functional (meth)acrylic acid ester compounds Examples include trimethylolpropane tri(meth)acrylate, trimethylolethane tri(meth)acrylate, tetramethylolmethane tri(meth)acrylate, pentaerythritol tetra(meth)acrylate, dipentaerythritol hexa(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.

[0032] [Mono(meth)acrylic acid ester compounds (E-1), (E-2)] The dental restorative hardenable composition of the present invention is a dental restorative hardenable composition comprising a mono(meth)acrylic acid ester compound (E-1) represented by the following general formula (I) and a mono(meth)acrylic acid ester compound (E-2) represented by the following general formula (II), from the viewpoints of being able to reduce the viscosity of the dental restorative hardenable composition, imparting excellent paste workability, and imparting high mechanical strength and water resistance to the cured product: [ka] [ka] [In the formula, R 1 and R 2 are each independently a group represented by the following general formula (i) or a group represented by the following general formula (ii), and X is a divalent hydrocarbon group having 1 to 6 carbon atoms or an oxygen atom. [ka] [ka] (In the formula, R 3 and R 5 are each independently a divalent hydrocarbon group having 1 to 10 carbon atoms, and R 4 and R 6 are each independently a hydrogen atom or a methyl group, and k and l are each independently an integer of 0 to 6.)] It may contain at least one selected from the group consisting of:

[0033] The mono(meth)acrylic acid ester compounds (E-1) and (E-2) have a skeleton represented by the above general formula (I) and a skeleton represented by the above general formula (II) that are rigid and hydrophobic, and therefore the cured product of the obtained dental restorative hardenable composition has low water absorption and can suppress a decrease in mechanical strength. The mono(meth)acrylic acid ester compound (E-1) and the mono(meth)acrylic acid ester compound (E-2) will be described below.

[0034] Each symbol in formula (I) will be explained. 1 is a group represented by the above general formula (i) or a group represented by the general formula (ii), and in formula (i) or (ii), R 4 and R 6 are each independently a hydrogen atom or a methyl group. 3 and R 5 are each independently a divalent hydrocarbon group having 1 to 10 carbon atoms. The hydrocarbon group preferably has 1 to 6 carbon atoms, more preferably 1 to 4 carbon atoms, and even more preferably 1 to 3 carbon atoms, in order to provide a dental restorative hardenable composition having good paste workability and excellent mechanical strength after hardening. Examples of the hydrocarbon group include a linear or branched alkylene group having 1 to 10 carbon atoms; a cycloalkylene group having 3 to 10 carbon atoms; and a phenylene group. k and l each independently represent an integer of 0 to 6. In order to provide a dental restorative hardenable composition having a low viscosity, suppressing the generation of bubbles in the hardened product, and providing excellent hardening properties, k is preferably 0 to 4, more preferably 0 to 3, even more preferably 0 to 2, and particularly preferably 0 or 1. Furthermore, l is preferably 0 to 4, more preferably 0 to 2, and even more preferably 0 or 1.

[0035] Examples of the mono(meth)acrylic acid ester compound (E-1) include o-phenylphenol(meth)acrylate, m-phenylphenol(meth)acrylate, p-phenylphenol(meth)acrylate, methoxylated-o-phenylphenol(meth)acrylate, methoxylated-m-phenylphenol(meth)acrylate, methoxylated-p-phenylphenol(meth)acrylate, ethoxylated-o-phenylphenol(meth)acrylate, ethoxylated-m-phenylphenol(meth)acrylate, ethoxylated-p-phenylphenol(meth)acrylate, propoxylated-o-phenylphenol(meth)acrylate, propoxylated-m-phenylphenol(meth)acrylate, propoxylated-p-phenylphenol(meth)acrylate, butoxylated-o-phenylphenol(meth)acrylate, butoxylated-m-phenylphenol(meth)acrylate, and butoxylated-p-phenylphenol(meth)acrylate. These may be used alone or in combination of two or more. Among these, in terms of the good workability of the paste of the obtained dental restorative hardenable composition and excellent mechanical strength after hardening, ethoxylated-o-phenylphenol acrylate, ethoxylated-m-phenylphenol acrylate, ethoxylated-p-phenylphenol acrylate, propoxylated-o-phenylphenol acrylate, propoxylated-m-phenylphenol acrylate, and propoxylated-p-phenylphenol acrylate are more preferred, ethoxylated-o-phenylphenol acrylate, ethoxylated-m-phenylphenol acrylate, and ethoxylated-p-phenylphenol acrylate are even more preferred, ethoxylated-o-phenylphenol acrylate and ethoxylated-m-phenylphenol acrylate are particularly preferred, and ethoxylated-o-phenylphenol acrylate is most preferred.

[0036] Each symbol in formula (II) will be explained. In formula (II), X is a divalent hydrocarbon group having 1 to 6 carbon atoms or an oxygen atom, and an oxygen atom is preferred because the resulting dental restorative hardenable composition has good paste handling properties and excellent mechanical strength after hardening.2 is a group represented by the above general formula (i) or general formula (ii), and in terms of the fact that the paste of the resulting dental restorative hardenable composition has good workability and excellent mechanical strength after hardening, R 4 and R 6 are each independently a hydrogen atom or a methyl group. 3 and R 5 are each independently a divalent hydrocarbon group having 1 to 10 carbon atoms. The hydrocarbon group preferably has 1 to 6 carbon atoms, more preferably 1 to 4 carbon atoms, and even more preferably 1 to 3 carbon atoms, in order to provide a dental restorative hardenable composition with good paste workability and excellent mechanical strength after hardening. Examples of the hydrocarbon group include linear or branched alkylene groups having 1 to 10 carbon atoms; cycloalkylene groups having 3 to 10 carbon atoms; and phenylene groups. Examples of alkylene groups include methylene, ethylene, n-propylene, isopropylene, n-butylene, and n-pentylene groups. Examples of cycloalkylene groups include cyclobutylene, cyclopentylene, cyclohexylene, and cycloheptylene groups. k and l each independently represent an integer of 0 to 6. From the viewpoints of good paste workability of the resulting dental restorative hardenable composition and excellent mechanical strength after hardening, k is preferably 0 to 4, more preferably 0 to 3, even more preferably 0 to 2, and particularly preferably 0 or 1. Furthermore, l is preferably 0 to 4, more preferably 0 to 2, and even more preferably 0 or 1.

[0037] Examples of the mono(meth)acrylic acid ester compound (E-2) include o-phenoxybenzyl (meth)acrylate, m-phenoxybenzyl (meth)acrylate, p-phenoxybenzyl (meth)acrylate, 2-(o-phenoxyphenyl)ethyl (meth)acrylate, 2-(m-phenoxyphenyl)ethyl (meth)acrylate, 2-(p-phenoxyphenyl)ethyl (meth)acrylate, 3-(o-phenoxyphenyl)propyl (meth)acrylate, 3-(m-phenoxyphenyl)propyl (meth)acrylate, 3-(p-phenoxyphenyl)propyl (meth)acrylate, Examples of such acrylates include 4-(o-phenoxyphenyl)butyl (meth)acrylate, 4-(m-phenoxyphenyl)butyl (meth)acrylate, 4-(p-phenoxyphenyl)butyl (meth)acrylate, 5-(o-phenoxyphenyl)pentyl (meth)acrylate, 5-(m-phenoxyphenyl)pentyl (meth)acrylate, 5-(p-phenoxyphenyl)pentyl (meth)acrylate, 6-(o-phenoxyphenyl)hexyl (meth)acrylate, 6-(m-phenoxyphenyl)hexyl (meth)acrylate, and 6-(p-phenoxyphenyl)hexyl (meth)acrylate. These may be used alone or in combination of two or more. Among these, o-phenoxybenzyl acrylate, m-phenoxybenzyl acrylate, p-phenoxybenzyl acrylate, 2-(o-phenoxyphenyl)ethyl acrylate, 2-(m-phenoxyphenyl)ethyl acrylate, and 2-(p-phenoxyphenyl)ethyl acrylate are more preferred, o-phenoxybenzyl acrylate, m-phenoxybenzyl acrylate, and p-phenoxybenzyl acrylate are even more preferred, o-phenoxybenzyl acrylate and m-phenoxybenzyl acrylate are particularly preferred, and m-phenoxybenzyl acrylate is most preferred, in that the resulting dental restorative hardenable composition has good paste operability and excellent mechanical strength after hardening.

[0038] The content of the mono(meth)acrylic acid ester compounds (E-1) and (E-2) in the dental restorative hardenable composition of the present invention is preferably 1 to 50 mass% relative to the total amount of polymerizable monomers, and from the viewpoint of superior mechanical strength, water resistance, and paste workability, is more preferably 5 to 40 mass%, and even more preferably 10 to 30 mass%. The mono(meth)acrylic acid ester compounds (E-1) and (E-2) may each be used alone or in combination of two or more.

[0039] The polymerizable monomer contained in the dental restorative hardenable composition of the present invention may be a (meth)acrylic acid ester compound (A), a (meth)acrylic acid ester compound (B) having two or more (meth)acryloyloxy groups, a mono(meth)acrylic acid ester compound other than the mono(meth)acrylic acid ester compounds (E-1) and (E-2), a (meth)acrylamide compound, an oxirane compound, or an oxetane compound. Examples of such polymerizable monomers include methyl (meth)acrylate, isobutyl (meth)acrylate, benzyl (meth)acrylate, lauryl (meth)acrylate, 2-(N,N-dimethylamino)ethyl (meth)acrylate, 2,3-dibromopropyl (meth)acrylate, 2-hydroxyethyl (meth)acrylate, 6-hydroxyhexyl (meth)acrylate, 10-hydroxydecyl (meth)acrylate, propylene glycol mono(meth)acrylate, glycerin mono(meth)acrylate, erythritol, and the like. Examples of suitable acrylic acid esters include acrylic acid esters such as acrylic acid esters (meth)acrylate, ...

[0040] The polymerizable monomer contained in the dental restorative hardenable composition of the present invention may be substantially composed of only the (meth)acrylic acid ester compound (A), the (meth)acrylic acid ester compound (B) having two or more (meth)acryloyloxy groups, and the mono(meth)acrylic acid ester compounds (E-1) and (E-2). The polymerizable monomers being substantially composed only of the (meth)acrylic acid ester compound (A), the (meth)acrylic acid ester compound (B) having two or more (meth)acryloyloxy groups, and the mono(meth)acrylic acid ester compounds (E-1) and (E-2) means that the content of polymerizable monomers other than the (meth)acrylic acid ester compound (A), the (meth)acrylic acid ester compound (B) having two or more (meth)acryloyloxy groups, and the mono(meth)acrylic acid ester compounds (E-1) and (E-2) is less than 10.0 mass%, preferably less than 5.0 mass%, more preferably less than 1.0 mass%, even more preferably less than 0.1 mass%, and particularly preferably less than 0.01 mass%, relative to the total amount of polymerizable monomers contained in the dental restorative hardenable composition.

[0041] The polymerizable monomer is preferably in a liquid state, but does not necessarily have to be in a liquid state at room temperature. Furthermore, even if the polymerizable monomer is in a solid state, it can be mixed and dissolved with other liquid polymerizable monomers and used.

[0042] The viscosity (25°C) of each polymerizable monomer is preferably 10 Pa s or less, more preferably 5 Pa s or less, and even more preferably 2 Pa s or less. On the other hand, when two or more polymerizable monomers are used as a mixture or diluted in a solvent, the viscosity of each polymerizable monomer does not need to be within the above range, and it is preferable that the viscosity of the polymerizable monomer in the state used (mixed or diluted state) is within the above range.

[0043] [Inorganic filler (C)] The inorganic filler (C) used in the present invention is inorganic particles having an average primary particle diameter of 0.01 to 5 μm, which are used as fillers in dental composite resins. The use of such inorganic particles results in excellent smoothness durability and mechanical strength of the cured product, as well as excellent paste workability. Examples of the inorganic particles include various types of glass (e.g., silicon dioxide (quartz, quartz glass, silica gel, etc.), silicon-based particles containing boron and / or aluminum together with various heavy metals), alumina, various ceramics, diatomaceous earth, kaolin, clay minerals (e.g., montmorillonite), activated clay, synthetic zeolite, mica, silica, calcium fluoride, ytterbium fluoride, calcium phosphate, barium sulfate, zirconium dioxide (zirconia), titanium dioxide (titania), and hydroxyapatite. The inorganic filler (C) may be used singly or in combination of two or more types.

[0044] Important physical properties desired for dental materials include transparency and radiopaque properties similar to those of natural teeth. Transparency can be achieved by matching the refractive index of the inorganic filler (C) with that of the polymer of the polymerizable monomer as closely as possible. On the other hand, radiopaque properties can be imparted by using an inorganic filler (e.g., oxide) containing a heavy metal element such as zirconium, barium, titanium, lanthanum, or strontium as the inorganic filler (C). The refractive index of such inorganic fillers containing heavy metal elements is typically high, ranging from 1.45 to 1.65. In the present invention, for example, the refractive index of the cured product of the (meth)acrylic acid ester compound (A), the (meth)acrylic acid ester compound (B), and the mono(meth)acrylic acid ester compound (E) constituting the polymerizable monomers forming the polymer is typically within the range of 1.45 to 1.65. Therefore, even when combined with such a high-refractive-index inorganic filler having radiopaque properties, the refractive index difference can be adjusted to a small value, thereby improving the transparency of the resulting dental material.

[0045] Examples of the inorganic filler having a high refractive index that can impart the above-mentioned X-ray contrast properties include barium borosilicate glass (e.g., "E-3000" manufactured by Esstech, and "8235", "GM27884", "GM39923" manufactured by Schott), strontium boroaluminosilicate glass (e.g., "E-4000" manufactured by Esstech, and "G018-093", "GM32087" manufactured by Schott), lanthanum glass (e.g., "GM31684" manufactured by Schott), fluoroaluminosilicate glass, and the like. Examples of such glasses include glass containing zinc oxide (e.g., "G018-091" and "G018-117" manufactured by Schott), glass containing zirconia (e.g., "G018-310" and "G018-159" manufactured by Schott), glass containing strontium (e.g., "G018-163", "G018-093", "GM32087" manufactured by Schott), glass containing zinc oxide (e.g., "G018-161" manufactured by Schott), and glass containing calcium (e.g., "G018-309" manufactured by Schott).

[0046] The shape of the inorganic filler (C) is not particularly limited, and various shapes can be used, such as crushed, plate-like, scale-like, fibrous (short fiber, long fiber, etc.), needle-like, whisker-like, spherical, etc. The inorganic filler (C) may be a combination of different shapes among the above shapes as long as it satisfies the requirements of the present invention.

[0047] The inorganic filler (C) of the present invention has an average primary particle size of 0.01 to 5 μm. By using an inorganic filler (C) having an average primary particle size in this range, the dental restorative hardenable composition has excellent operability, and the hardened product has excellent smoothness durability and toughness. From these perspectives, the average primary particle size of the inorganic filler (C) is preferably 0.02 μm or more, more preferably 0.05 μm or more, and even more preferably 3 μm or less, and even more preferably 2 μm or less. If the average primary particle size is less than 0.01 μm, mechanical strength is likely to be impaired, while if it is more than 5 μm, brittleness may increase and toughness may decrease.

[0048] The average primary particle size of the inorganic filler (C) can be determined by laser diffraction scattering or electron microscope observation of particles. Specifically, laser diffraction scattering is convenient for measuring the particle size of particles 0.1 μm or more, and electron microscope observation is convenient for measuring the particle size of particles less than 0.1 μm. Note that laser diffraction scattering can be used to determine whether the particle size is 0.1 μm or more.

[0049] In the laser diffraction scattering method, for example, the average primary particle diameter can be determined by measuring on a volume basis using a laser diffraction particle size distribution analyzer (e.g., "SALD-2300" manufactured by Shimadzu Corporation) using a 0.2% aqueous solution of sodium hexametaphosphate as a dispersion medium.

[0050] In electron microscope observation, for example, an image of the particles is taken using a scanning electron microscope (SEM; for example, Hitachi High-Technologies Corporation's "SU3500H-800NA" model, etc.), and the particle sizes of the particles (200 or more) observed within a unit field of view of the SEM image are measured using image analysis particle size distribution measurement software (Mountec Corporation's "Mac-View" or similar), to determine the average primary particle size. In this case, the particle size of a particle is determined as the equivalent circle diameter, which is the diameter of a circle having the same area as the particle, and the average primary particle size is calculated from the number of particles and their particle sizes.

[0051] The content of the inorganic filler (C) in the dental restorative hardenable composition of the present invention is not particularly limited, but is preferably 50 to 95 mass %, more preferably 55 to 90 mass %, and even more preferably 60 to 85 mass %, of the total amount of the dental restorative hardenable composition. When the content of the inorganic filler (C) is 50 mass % or more of the total amount of the dental restorative hardenable composition, the mechanical strength of the resulting cured product can be further improved. Furthermore, when the content of the inorganic filler (C) is 95 mass % or less of the total amount of the dental restorative hardenable composition, the toughness of the resulting cured product can be further improved.

[0052] The inorganic filler (C) in the present invention is preferably one that has been surface-treated in advance with a surface treatment agent. By using a surface-treated inorganic filler (C), the mechanical strength of the resulting dental restorative hardenable composition after hardening can be further improved. When two or more inorganic fillers (C) are used, only one of them may be surface-treated, or all of them may be surface-treated. In the latter case, inorganic fillers (C) that have been individually surface-treated may be mixed, or multiple inorganic fillers may be mixed in advance and surface-treated all at once.

[0053] As such a surface treatment agent, a known surface treatment agent can be used, and an organometallic compound such as an organosilicon compound, an organotitanium compound, an organozirconium compound, or an organoaluminum compound, or an acidic group-containing organic compound having at least one acidic group such as a phosphate group, a pyrophosphate group, a thiophosphate group, a phosphonate group, a sulfonate group, or a carboxylic acid group, can be used. When two or more surface treatment agents are used, the surface treatment layer may be a mixture of two or more surface treatment agents, or may be a multi-layered surface treatment layer in which multiple surface treatment agent layers are laminated. Furthermore, the surface treatment method can be a known method without any particular limitation.

[0054] The organosilicon compound includes R 7 n SiY (4-n) (wherein R 7 represents a substituted or unsubstituted hydrocarbon group having 1 to 12 carbon atoms, Y represents an alkoxy group having 1 to 4 carbon atoms, an acetoxy group, a hydroxyl group, a halogen atom, or a hydrogen atom, and n represents an integer of 0 to 3, provided that R 7 and when there are a plurality of Y's, they may be the same or different).

[0055] Specific examples include methyltrimethoxysilane, dimethyldimethoxysilane, phenyltrimethoxysilane, diphenyldimethoxysilane, methyltriethoxysilane, dimethyldiethoxysilane, phenyltriethoxysilane, diphenyldiethoxysilane, isobutyltrimethoxysilane, vinyltrimethoxysilane, vinyltriethoxysilane, vinyltris(β-methoxyethoxy)silane, 3,3,3-trifluoropropyltrimethoxysilane, methyl-3,3,3-trifluoropropyldimethoxysilane, β-(3,4-epoxycyclohexyl)ethyltrimethoxysilane, γ-glycidoxypropyltrimethoxysilane, γ-glycidoxypropylmethyldiethoxysilane, γ-glycidoxypropyltriethoxysilane, γ-methacryloyloxypropylmethyldimethoxysilane, γ-methacryloyloxypropylmethyldiethoxysilane, N-β(aminoethyl)γ-aminopropylmethyldimethoxysilane, N-β(aminoethyl)γ-aminopropyltrimethoxysilane, N-β(aminoethyl)γ-aminopropyltriethoxysilane, γ-aminopropyltrimethoxysilane, γ-aminopropyltriethoxysilane, N-phenyl-γ-aminopropyltrimethoxysilane, γ-mercaptopropyltrimethoxysilane, trimethylsilanol, methyltrichlorosilane, methyldichlorosilane, dimethyldichlorosilane, trimethylchlorosilane, phenyltrichlorosilane, diphenyldichlorosilane, vinyltrichlorosilane, trimethylbromosilane, diethylsilane, vinyltriacetoxysilane, ω-(meth)acryloyloxyalkyltrimethoxysilane [number of carbon atoms between the (meth)acryloyloxy group and the silicon atom: 3 to 12, e.g., γ-methacryloyloxypropyltrimethoxysilane, etc.], ω-(meth)acryloyloxyalkyltriethoxysilane [number of carbon atoms between the (meth)acryloyloxy group and the silicon atom: 3 to 12, for example, γ-methacryloyloxypropyltriethoxysilane, etc. In the present invention, the expression "(meth)acryloyloxy" is used to mean both methacryloyloxy and acryloyloxy.

[0056] Among these, coupling agents having a functional group copolymerizable with the polymerizable monomer, such as ω-(meth)acryloyloxyalkyltrimethoxysilane [number of carbon atoms between the (meth)acryloyloxy group and the silicon atom: 3 to 12], ω-(meth)acryloyloxyalkyltriethoxysilane [number of carbon atoms between the (meth)acryloyloxy group and the silicon atom: 3 to 12], vinyltrimethoxysilane, vinyltriethoxysilane, vinyltriacetoxysilane, and γ-glycidoxypropyltrimethoxysilane are preferably used.

[0057] Examples of the organic titanium compound include tetramethyl titanate, tetraisopropyl titanate, tetra-n-butyl titanate, butyl titanate dimer, and tetra(2-ethylhexyl) titanate.

[0058] Examples of the organic zirconium compound include zirconium isopropoxide, zirconium n-butoxide, zirconium acetylacetonate, and zirconium acetate.

[0059] Examples of the organoaluminum compound include aluminum acetylacetonate and aluminum organic acid salt chelate compounds.

[0060] Examples of the acidic group-containing organic compound having a phosphoric acid group include 2-ethylhexyl acid phosphate, stearyl acid phosphate, 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)acryloyloxypentyl dihydrogen phosphate, 8-(meth)acryloyloxyhexyl dihydrogen phosphate, 9-(meth)acryloyloxyhexyl dihydrogen phosphate, 10-(meth)acryloyloxyhexyl dihydrogen phosphate, 11-(meth)acryloyloxyhexyl dihydrogen phosphate, 12-(meth)acryloyloxyhexyl dihydrogen phosphate, 13-(meth)acryloyloxyhexyl dihydrogen phosphate, 14-(meth)acryloyloxyhexyl dihydrogen phosphate, 15-(meth)acryloyloxyhexyl dihydrogen phosphate, 16-(meth)acryloyloxyhexyl dihydrogen phosphate, 17-(meth)acryloyloxyhexyl dihydrogen phosphate, 18-(meth)acryloyloxyhexyl dihydrogen phosphate, 19-(meth)acryloyloxyhexyl dihydrogen phosphate, 20-(meth)acryloyloxyhexyl dihydrogen phosphate, 22-(meth)acryloyloxyhexyl dihydrogen phosphate, 23-(meth)acryloyloxyhexyl dihydrogen phosphate, 24-(meth)acryloyloxyhexyl dihydrogen phosphate, 25-(meth)acryloyloxyhexyl dihydrogen phosphate, 26-(meth)acryloyloxyhexyl dihydrogen phosphate, 27-(meth)ac 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)acryloyloxydodecyl dihydrogen phosphate Hydrogen phosphate, 16-(meth)acryloyloxyhexadecyl dihydrogen phosphate, 20-(meth)acryloyloxyicosyl dihydrogen phosphate, bis[2-(meth)acryloyloxyethyl]hydrogen phosphate, bis[4-(meth)acryloyloxybutyl]hydrogen phosphate, bis[6-(meth)acryloyloxyhexyl]hydrogen phosphate, bis[8-(meth)acryloyloxy

[0033] Examples of suitable alkyl acrylates include bis[9-(meth)acryloyloxynonyl]hydrogenphosphate, bis[10-(meth)acryloyloxydecyl]hydrogenphosphate, 1,3-di(meth)acryloyloxypropyl dihydrogenphosphate, 2-(meth)acryloyloxyethylphenylhydrogenphosphate, 2-(meth)acryloyloxyethyl-2-bromoethylhydrogenphosphate, bis[2-(meth)acryloyloxy-(1-hydroxymethyl)ethyl]hydrogenphosphate, and acid chlorides, alkali metal salts, and ammonium salts thereof.

[0061] Furthermore, as the acidic group-containing organic compound having an acidic group such as a pyrophosphate group, a thiophosphate group, a phosphonate group, a sulfonic acid group, or a carboxylic acid group, for example, those described in WO 2012 / 042911 can be suitably used.

[0062] The above surface treatment agents may be used alone or in combination of two or more. In order to enhance the chemical bonding between the inorganic filler (C) and the polymerizable monomer and thereby improve the mechanical strength of the cured product, it is more preferable to use an acidic group-containing organic compound having a functional group copolymerizable with the polymerizable monomer.

[0063] The amount of the surface treatment agent used is not particularly limited, and is preferably, for example, 0.1 to 50 parts by mass per 100 parts by mass of the inorganic filler (C).

[0064] [Polymerization initiator (D)] Next, the polymerization initiator (D) of the present invention will be described. Examples of the polymerization initiator (D) include thermal polymerization initiators, photopolymerization initiators, and chemical polymerization initiators. These may be used alone or in combination of two or more.

[0065] Examples of the thermal polymerization initiator include organic peroxides and azo compounds.

[0066] Examples of the organic peroxide include ketone peroxides, hydroperoxides, diacyl peroxides, dialkyl peroxides, peroxyketals, peroxyesters, and peroxydicarbonates.

[0067] Examples of the ketone peroxide include methyl ethyl ketone peroxide, methyl isobutyl ketone peroxide, methyl cyclohexanone peroxide, and cyclohexanone peroxide.

[0068] Examples of the hydroperoxide include 2,5-dimethylhexane-2,5-dihydroperoxide, diisopropylbenzene hydroperoxide, cumene hydroperoxide, t-butyl hydroperoxide, and 1,1,3,3-tetramethylbutyl hydroperoxide.

[0069] Examples of the diacyl peroxide include acetyl peroxide, isobutyryl peroxide, benzoyl peroxide, decanoyl peroxide, 3,5,5-trimethylhexanoyl peroxide, 2,4-dichlorobenzoyl peroxide, and lauroyl peroxide.

[0070] Examples of the dialkyl peroxide include di-t-butyl peroxide, dicumyl peroxide, t-butylcumyl peroxide, 2,5-dimethyl-2,5-di(t-butylperoxy)hexane, 1,3-bis(t-butylperoxyisopropyl)benzene, and 2,5-dimethyl-2,5-di(t-butylperoxy)-3-hexyne.

[0071] Examples of the peroxyketal include 1,1-bis(t-butylperoxy)-3,3,5-trimethylcyclohexane, 1,1-bis(t-butylperoxy)cyclohexane, 2,2-bis(t-butylperoxy)butane, 2,2-bis(t-butylperoxy)octane, and 4,4-bis(t-butylperoxy)valeric acid-n-butyl ester.

[0072] Examples of the peroxyester include α-cumyl peroxyneodecanoate, t-butyl peroxyneodecanoate, t-butyl peroxypivalate, 2,2,4-trimethylpentylperoxy-2-ethylhexanoate, t-amyl peroxy-2-ethylhexanoate, t-butyl peroxy-2-ethylhexanoate, di-t-butylperoxyisophthalate, di-t-butylperoxyhexahydroterephthalate, t-butylperoxy-3,3,5-trimethylhexanoate, t-butyl peroxyacetate, t-butyl peroxybenzoate, and t-butyl peroxymaleic acid.

[0073] Examples of the peroxydicarbonate include di-3-methoxyperoxydicarbonate, di(2-ethylhexyl)peroxydicarbonate, bis(4-t-butylcyclohexyl)peroxydicarbonate, diisopropylperoxydicarbonate, di-n-propylperoxydicarbonate, di(2-ethoxyethyl)peroxydicarbonate, and diallylperoxydicarbonate.

[0074] Among these organic peroxides, diacyl peroxides are preferred in terms of the overall balance of safety, storage stability, and radical generating ability, and among these, benzoyl peroxide is more preferred.

[0075] Examples of the azo compound include 2,2'-azobis(isobutyronitrile), 2,2'-azobis(2,4-dimethylvaleronitrile), 4,4'-azobis(4-cyanovaleric acid), 1,1'-azobis(cyclohexane-1-carbonitrile), dimethyl-2,2'-azobis(isobutyrate), and 2,2'-azobis(2-amidinopropane) dihydrochloride.

[0076] Examples of the photopolymerization initiator include (bis)acylphosphine oxides, α-diketones, and coumarins.

[0077] Among the (bis)acylphosphine oxides, examples of the acylphosphine oxides include 2,4,6-trimethylbenzoyldiphenylphosphine oxide, 2,6-dimethoxybenzoyldiphenylphosphine oxide, 2,6-dichlorobenzoyldiphenylphosphine oxide, 2,4,6-trimethylbenzoylmethoxyphenylphosphine oxide, 2,4,6-trimethylbenzoylethoxyphenylphosphine oxide, 2,3,5,6-tetramethylbenzoyldiphenylphosphine oxide, benzoyldi(2,6-dimethylphenyl)phosphonate, and salts thereof. 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, bis(2,5,6-trimethylbenzoyl)-2,4,4-trimethylpentylphosphine oxide, and salts thereof.

[0078] Among these (bis)acylphosphine oxides, 2,4,6-trimethylbenzoyldiphenylphosphine oxide, 2,4,6-trimethylbenzoylmethoxyphenylphosphine oxide, bis(2,4,6-trimethylbenzoyl)phenylphosphine oxide and 2,4,6-trimethylbenzoylphenylphosphine oxide sodium salt are preferred.

[0079] Examples of the α-diketones include diacetyl, benzyl, camphorquinone, 2,3-pentadione, 2,3-octadione, 9,10-phenanthrenequinone, 4,4′-oxybenzyl, acenaphthenequinone, etc. Among these, camphorquinone is preferred.

[0080] Examples of the 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, and 3-(p-nitrobenzoyl)coumarin. 3,5-carbonylbis(7-methoxycoumarin), 3-benzoyl-6-bromocoumarin, 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, 7-methoxy-3-(p-nitro benzoyl)coumarin, 3-(p-nitrobenzoyl)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-dimethylbenzothiazol-2-ylidene)acetyl]coumarin, 3-[(1-methylnaphtho[1,2-d]thiazol-2-ylidene)acetyl]coumarin, 3,3'-carbonylbis(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-benzimidazolyl)-7-(diethylamino)coumarin, 3-(2-benzothiazolyl)-7-(dioctylamino)coumarin, 3-acetyl-7-(dimethylamino)coumarin, 3,3'-carbonylbis(7-dibutylaminocoumarin), 3,3'-carbonyl-7-diethylaminocoumarin-7'-bis(butoxyethyl)aminocoumarin Examples of compounds include those described in JP-A-9-3109 and JP-A-10-245525, such as 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]quinolizin-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]quinolizin-11-one.

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

[0082] Among these photopolymerization initiators, it is preferable to use at least one selected from the group consisting of (bis)acylphosphine oxides, α-diketones, and coumarins, which are widely used in dental curable compositions.

[0083] Furthermore, if necessary, the photopolymerization initiator may be further combined with a polymerization accelerator to allow photopolymerization to be carried out more efficiently in a shorter time.

[0084] Polymerization accelerators suitable for photopolymerization initiators include mainly tertiary amines, aldehydes, compounds having a thiol group, sulfinic acid and / or salts thereof, and the like.

[0085] Examples of tertiary amines include N,N-dimethylaniline, N,N-dimethyl-p-toluidine, N,N-dimethyl-m-toluidine, N,N-diethyl-p-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, and N,N-dimethyl-3,5-di-t-butylaniline. , N,N-bis(2-hydroxyethyl)-3,5-dimethylaniline, N,N-di(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 Examples of the methyl methyl aniline include propylaniline, N,N-bis(2-hydroxyethyl)-3,5-di-t-butylaniline, n-butoxyethyl 4-(N,N-dimethylamino)benzoate, (2-methacryloyloxy)ethyl 4-(N,N-dimethylamino)benzoate, ethyl 4-(N,N-dimethylamino)benzoate, butyl 4-(N,N-dimethylamino)benzoate, N-methyldiethanolamine, 4-(N,N-dimethylamino)benzophenone, trimethylamine, triethylamine, N-methyldiethanolamine, N-ethyldiethanolamine, Nn-butyldiethanolamine, N-lauryldiethanolamine, triethanolamine, 2-(dimethylamino)ethyl methacrylate, N-methyldiethanolamine dimethacrylate, N-ethyldiethanolamine dimethacrylate, triethanolamine monomethacrylate, triethanolamine dimethacrylate, and triethanolamine trimethacrylate.

[0086] Examples of aldehydes include dimethylaminobenzaldehyde, terephthalaldehyde, etc. Examples of compounds having a thiol group include 2-mercaptobenzoxazole, decanethiol, 3-mercaptopropyltrimethoxysilane, thiobenzoic acid, etc.

[0087] Examples of sulfinic acids and salts thereof include benzenesulfinic acid, sodium benzenesulfinate, potassium benzenesulfinate, calcium benzenesulfinate, lithium benzenesulfinate, p-toluenesulfinic acid, sodium p-toluenesulfinate, potassium p-toluenesulfinate, calcium p-toluenesulfinate, lithium p-toluenesulfinate, 2,4,6-trimethylbenzenesulfinic acid, sodium 2,4,6-trimethylbenzenesulfinate, potassium 2,4,6-trimethylbenzenesulfinate, and 2,4,6-trimethylbenzenesulfinate. Examples thereof include calcium benzenesulfinate, lithium 2,4,6-trimethylbenzenesulfinate, 2,4,6-triethylbenzenesulfinic acid, sodium 2,4,6-triethylbenzenesulfinate, potassium 2,4,6-triethylbenzenesulfinate, calcium 2,4,6-triethylbenzenesulfinate, 2,4,6-triisopropylbenzenesulfinic acid, sodium 2,4,6-triisopropylbenzenesulfinate, potassium 2,4,6-triisopropylbenzenesulfinate, and calcium 2,4,6-triisopropylbenzenesulfinate.

[0088] As the chemical polymerization initiator, redox polymerization initiators such as organic peroxides and amines, or organic peroxides, amines, and sulfinic acids (or their salts) are preferably used. When using a redox polymerization initiator, the oxidizing agent and reducing agent must be packaged separately and mixed immediately before use. Examples of oxidizing agents for redox polymerization initiators include organic peroxides. The organic peroxides used as oxidizing agents for redox polymerization initiators are not particularly limited, and known organic peroxides can be used. Specific examples include the organic peroxides exemplified above for the thermal polymerization initiator.

[0089] Among these organic peroxides, diacyl peroxides are preferably used in view of the overall balance of safety, storage stability, and radical generating ability, and among these, benzoyl peroxide is more preferably used.

[0090] As a reducing agent for a redox polymerization initiator, an aromatic tertiary amine having no electron-withdrawing group on the aromatic ring is usually used. Examples of aromatic tertiary amines having no electron-withdrawing group on the aromatic ring include N,N-dimethylaniline, N,N-dimethyl-p-toluidine, N,N-dimethyl-m-toluidine, N,N-diethyl-p-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, N,N-bis(2-hydroxyethyl aniline), ... 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, and N,N-bis(2-hydroxyethyl)-3,5-di-t-butylaniline.

[0091] The chemical polymerization initiator may be used in combination with a polymerization accelerator, if necessary. The polymerization accelerator for the chemical polymerization initiator can be selected from polymerization accelerators used in general industry, and polymerization accelerators used in dental applications are preferably used. The polymerization accelerator may be used alone or in appropriate combination of two or more. Specific examples include amines, sulfinic acids and their salts, copper compounds, and tin compounds.

[0092] Amines used as polymerization accelerators for chemical polymerization initiators are divided into aliphatic amines and aromatic amines having an electron-withdrawing group on the aromatic ring. Examples of aliphatic amines include aliphatic primary amines such as n-butylamine, n-hexylamine, and n-octylamine; aliphatic secondary amines such as diisopropylamine, dibutylamine, and N-methylethanolamine; and aliphatic tertiary 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, aliphatic tertiary amines are preferred from the viewpoint of the curability and storage stability of the composition, and N-methyldiethanolamine and triethanolamine are more preferably used.

[0093] Examples of aromatic tertiary amines having an electron-withdrawing group on the aromatic ring and used as polymerization accelerators for chemical polymerization initiators include ethyl 4-(N,N-dimethylamino)benzoate, methyl 4-(N,N-dimethylamino)benzoate, n-butoxyethyl 4-(N,N-dimethylamino)benzoate, 2-(methacryloyloxy)ethyl 4-N,N-dimethylaminobenzoate, 4-(N,N-dimethylamino)benzophenone, butyl 4-(N,N-dimethylamino)benzoate, etc. Among these, at least one selected from the group consisting of N,N-di(2-hydroxyethyl)-p-toluidine, ethyl 4-(N,N-dimethylamino)benzoate, n-butoxyethyl 4-(N,N-dimethylaminobenzoate, and 4-(N,N-dimethylamino)benzophenone is preferably used from the viewpoint of imparting excellent curability to the composition.

[0094] Examples of sulfinic acid and salts thereof used as the polymerization accelerator include those exemplified above as the polymerization accelerator for the photopolymerization initiator, and sodium benzenesulfinate, sodium p-toluenesulfinate, and sodium 2,4,6-triisopropylbenzenesulfinate are preferred.

[0095] Suitable copper compounds used as polymerization accelerators include, for example, copper acetylacetonate, copper (II) acetate, copper oleate, copper (II) chloride, and copper (II) bromide.

[0096] Examples of tin compounds used as polymerization accelerators include di-n-butyltin dimaleate, di-n-octyltin dimaleate, di-n-octyltin dilaurate, di-n-butyltin dilaurate, etc. Particularly preferred tin compounds are di-n-octyltin dilaurate and di-n-butyltin dilaurate.

[0097] Among these, for dental composite resins, it is preferable to use a photopolymerization initiator because of the ease of hardening in the oral cavity, while for dental mill blanks, it is preferable to use a thermal polymerization initiator because it increases the degree of polymerization and improves strength.

[0098] The content of the polymerization initiator (D) in the present invention is not particularly limited, but from the viewpoint of the curability of the resulting composition, it is preferably 0.001 to 30 parts by mass per 100 parts by mass of the polymerizable monomer. When the content of the polymerization initiator (D) is 0.001 part by mass or more per 100 parts by mass of the polymerizable monomer, polymerization proceeds sufficiently without risk of a decrease in mechanical strength, and the content is more preferably 0.05 part by mass or more, and even more preferably 0.1 part by mass or more. On the other hand, when the content of the polymerization initiator (D) is 30 parts by mass or less per 100 parts by mass of the polymerizable monomer, sufficient mechanical strength can be obtained even when the polymerization performance of the polymerization initiator itself is low, and furthermore, there is no risk of precipitation from the composition, and the content is more preferably 20 parts by mass or less.

[0099] In addition to the above components, the dental restorative hardenable composition of the present invention may further contain, depending on the purpose, pH adjusters, ultraviolet absorbers, antioxidants, colorants (pigments, dyes), antibacterial agents, X-ray contrast agents, thickeners, fluorescent agents, crosslinkers (metal ion-releasing components such as polyvalent metal ion-releasing fillers, etc.) etc. In one embodiment, the dental restorative hardenable composition does not contain metal ion-releasing components such as polyvalent metal ion-releasing fillers, etc., in order to suppress an increase in crosslink density, since an excessively high crosslink density increases brittleness.

[0100] The pigment may be any known pigment used in dental composite resins without any limitation. The pigment may be either an inorganic pigment or an organic pigment. Examples of the inorganic pigment include chromates such as yellow lead, zinc yellow, and barium yellow; ferrocyanides such as iron blue; sulfides such as vermilion, cadmium yellow, zinc sulfide, and cadmium red; sulfates such as barium sulfate, zinc sulfate, and strontium sulfate; oxides such as antimony white, zinc white, titanium white, red iron oxide, iron black, and chromium oxide; hydroxides such as aluminum hydroxide; silicates such as calcium silicate and ultramarine; and carbon such as carbon black and graphite. Examples of organic pigments include nitrone pigments such as Naphthol Green B and Naphthol Green Y; nitro pigments such as Naphthol Yellow S and Lithol Fast Yellow 2G; insoluble azo pigments such as Permanent Red 4R, Brilliant Fast Scarlet, Hansa Yellow, and Benzidine Yellow; sparingly soluble azo pigments such as Lithol Red, Lake Red C, and Lake Red D; soluble azo pigments such as Brilliant Carmine 6B, Permanent Red F5R, Pigment Scarlet 3B, and Bordeaux 10B; phthalocyanine pigments such as Phthalocyanine Blue, Phthalocyanine Green, and Sky Blue; basic dye pigments such as Rhodamine Lake, Malachite Green Lake, and Methyl Violet Lake; and acid dye pigments such as Peacock Blue Lake, Eosin Lake, and Quinoline Yellow Lake. These pigments may be used alone or in combination, and the pigments may be selected appropriately depending on the desired color tone.

[0101] The content of the pigment in the dental restorative hardenable composition is not particularly limited, as it is adjusted appropriately depending on the desired color tone, but is preferably 0.000001 part by mass or more, more preferably 0.00001 part by mass or more, and preferably 5 parts by mass or less, more preferably 1 part by mass or less, relative to 100 parts by mass of the dental restorative hardenable composition.

[0102] The method for producing the dental restorative hardenable composition of the present invention includes, for example, the following steps (1) and (2). (1) Mixing process The kneading step is a process of kneading. Polymerizable monomers, such as a (meth)acrylic acid ester compound (A) and a (meth)acrylic acid ester compound (B), and a polymerization initiator (D) are added to a kneader container to prepare a polymerizable monomer-containing composition. Then, an inorganic filler (C) is added and kneaded to produce a paste-like composition. The kneading method is not particularly limited as long as the effects of the present invention are achieved, and known methods can be used. However, kneading while heating is preferred from the viewpoint of shortening the kneading time and preventing paste variation. The kneading temperature is preferably 40 to 60°C. Temperatures below 40°C do not sufficiently shorten the kneading time, while temperatures above 60°C may result in polymerization and hardening or deterioration of the composition during kneading. Vacuum degassing can also be performed during kneading, if necessary. The degree of vacuum is not particularly limited, but a vacuum of 5 to 200 Torr is preferred to efficiently remove air bubbles.

[0103] (2) Defoaming process The degassing step is a process for performing a degassing operation. After the paste-like composition is placed in a degassing vessel, the composition is degassed by applying pressure to the outside of the vessel while removing bubbles from the paste by reducing the pressure. The degassing conditions are not particularly limited. However, to efficiently remove bubbles, a vacuum degree of 5 to 200 Torr is preferred to prevent separation of the polymerizable monomer-containing composition containing polymerizable monomers such as a (meth)acrylic acid ester compound (A) and a (meth)acrylic acid ester compound (B), and a polymerization initiator (D), from the inorganic filler (C). The degassing time is preferably 3 to 30 minutes. The pressure during extrusion is preferably 0.5 to 5 MPa. The pressurization time is preferably 3 to 30 minutes. During degassing, a heat treatment can be performed as needed. The temperature is not particularly limited, but a temperature of 40 to 60°C is preferred to efficiently remove bubbles.

[0104] The dental restorative hardenable composition of the present invention is suitable for use as a dental material because the cured product thereof exhibits high mechanical strength and toughness, excellent water resistance and smoothness durability, excellent workability, and suppression of air bubbles in the cured product, resulting in an excellent appearance. Specifically, the dental restorative hardenable composition of the present invention is suitable for use as a dental material (particularly a dental composite resin) that can partially or completely replace natural teeth in the field of dental care. Therefore, one embodiment of the present invention includes a dental composite resin comprising the dental restorative hardenable composition. Furthermore, the cured product obtained by polymerizing and curing the dental restorative hardenable composition of the present invention is suitable for use as a dental mill blank, a cutting material used in a CAD / CAM system that uses a milling machine to produce a dental mill blank. Therefore, another embodiment of the present invention includes a dental mill blank comprising a cured product of the dental restorative hardenable composition. [Example]

[0105] EXAMPLES The present invention will be specifically explained below by showing examples and comparative examples, but the present invention is not limited to the following examples.

[0106] [(Meth)acrylic acid ester compound (A)] PCIS-3: Synthesis example 1 PCN-23: Synthesis example 2 PCD-33: Synthesis Example 3 PARM: Synthesis example 4 PSM: Synthesis example 5 PCUMA: Synthesis Example 6

[0107] [(Meth)acrylic acid ester compound (B)] D2.6E: 2,2-bis[4-methacryloyloxypolyethoxyphenyl]propane (average number of moles of ethoxy groups added: 2.6) (manufactured by Shin-Nakamura Chemical Co., Ltd.) UDMA: [2,2,4-trimethylhexamethylenebis(2-carbamoyloxyethyl)]dimethacrylate (Kyoeisha Chemical Co., Ltd.) NPG: Neopentyl dimethacrylate (Kyoeisha Chemical Co., Ltd.) TEGDMA: Triethylene glycol dimethacrylate (manufactured by Shin-Nakamura Chemical Co., Ltd.)

[0108] [Inorganic filler (C)] Filler (F1): Manufacturing example A Filler (F2): Manufacturing example B Filler (F3): Manufacturing example C Filler (F5): Manufacturing example D [Organic filler] Filler (F4): J-4PY (acrylic beads J-4PY, average primary particle size: 2.2 μm, manufactured by Negami Chemical Industries, Ltd.)

[0109] [Polymerization initiator (D)] CQ: Camphorquinone (photopolymerization initiator) (Tokyo Chemical Industry Co., Ltd.) TPO: 2,4,6-trimethylbenzoyldiphenylphosphine oxide (photopolymerization initiator) (Tokyo Chemical Industry Co., Ltd.) THP: 1,1,3,3-tetramethylbutyl hydroperoxide (thermal polymerization initiator) (NOF Corporation) BPO: Benzoyl peroxide (thermal polymerization initiator) (NOF Corporation)

[0110] [Mono(meth)acrylic acid ester compound (E-1)] POBA: m-phenoxybenzyl acrylate (Kyoeisha Chemical Co., Ltd.)

[0111] [Mono(meth)acrylic acid ester compound (E-2)] EPPA: Ethoxylated o-phenylphenol acrylate (Shin-Nakamura Chemical Co., Ltd.)

[0112] [Surface treatment agent] γ-MPS: γ-methacryloyloxypropyltrimethoxysilane (Shin-Etsu Chemical Co., Ltd.) 11-MUS: 11-methacryloyloxydodecyltrimethoxysilane (Shin-Etsu Chemical Co., Ltd.)

[0113] [Polymerization accelerator] JJA: Ethyl 4-(N,N-dimethylamino)benzoate

[0114] [Synthesis Example 1: Synthesis of PCIS-3] 80 g of hydroxy-terminated polycarbonate diol "BENEBiOLH S0840H (molecular weight: 800, manufactured by Mitsubishi Chemical Corporation)" with an isosorbide skeleton, 40 g of triethylamine (molecular weight: 101.19), and 20 g of 4-dimethylaminopyridine (molecular weight: 122.17) were dissolved in methylene chloride. 24 g of methacryloyl chloride (molecular weight: 104.53) was added dropwise at 0°C, and the mixture was stirred at room temperature for 24 hours. The organic layer was then washed with distilled water, 1 M aqueous hydrochloric acid, and saturated aqueous sodium carbonate, followed by drying over magnesium sulfate. The dried solution was concentrated and poured into methanol. The precipitate was collected by filtration and vacuum dried to obtain PCIS-3 (number average molecular weight: 936), a methacrylate ester compound with a polycarbonate structure in which both terminal hydroxyl residues derived from the repeating units constituting the polymer structure were directly methacryloylated.

[0115] [Synthesis Example 2: Synthesis of PCN-23] 200 g of hydroxy-terminated polycarbonate diol "BENEBiOLH NL2030B (molecular weight: 2000, manufactured by Mitsubishi Chemical Corporation)" with a neopentyl skeleton, 40 g of triethylamine, and 20 g of 4-dimethylaminopyridine were dissolved in methylene chloride. 24 g of methacryloyl chloride was added dropwise at 0°C, and the mixture was stirred at room temperature for 24 hours. The organic layer was then washed successively with distilled water, 1 M aqueous hydrochloric acid, and saturated aqueous sodium carbonate, and then dried over magnesium sulfate. The dried solution was concentrated and poured into methanol. The precipitate was collected by filtration and vacuum dried to obtain PCN-23 (number average molecular weight: 2136), a methacrylate ester compound with a polycarbonate structure in which both terminal hydroxyl residues derived from the repeating units constituting the polymer structure were directly methacryloylated.

[0116] [Synthesis Example 3: Synthesis of PCD-33] 300 g of decyl-backbone-containing hydroxy-terminated polycarbonate diol "BENEBiOLH NL3010DB (molecular weight: 3000, manufactured by Mitsubishi Chemical Corporation)," 40 g of triethylamine, and 20 g of 4-dimethylaminopyridine were dissolved in methylene chloride. 24 g of methacryloyl chloride was added dropwise at 0°C, and the mixture was stirred at room temperature for 24 hours. The organic layer was then washed with distilled water, 1 M aqueous hydrochloric acid, and saturated aqueous sodium carbonate, followed by drying over magnesium sulfate. The dried solution was concentrated and poured into methanol. The precipitate was collected by filtration and vacuum dried to obtain PCD-33 (number average molecular weight: 3136), a methacrylate ester compound with a polycarbonate structure in which both terminal hydroxyl residues derived from the repeating units constituting the polymer structure were directly methacryloylated.

[0117] [Synthesis Example 4: Synthesis of PARM] 85 g of bisphenol A (molecular weight: 228.29) and 30 g of sodium hydroxide (molecular weight: 40.00) were dissolved in distilled water, and 10 mg of tetrabutylammonium bromide (molecular weight: 322.37) was added. The mixture was stirred at room temperature for 10 minutes. After that, a methylene chloride solution containing 30 g of terephthaloyl chloride (molecular weight: 203.02) was added dropwise and vigorously stirred at room temperature for 1 hour. The organic layer was then washed with distilled water and dried over magnesium sulfate. The dried solution was concentrated and poured into a 15:1 methanol / water mixture. The precipitate was collected by filtration and vacuum dried to obtain "PAROH (molecular weight: 900)," a polyarylate with hydroxyl groups at both ends. 90 g of the resulting PAROH, 40 g of triethylamine, and 20 g of 4-dimethylaminopyridine were dissolved in methylene chloride. 24 g of methacryloyl chloride was added dropwise at 0°C, and the mixture was stirred at room temperature for 24 hours. The organic layer was then washed with distilled water, 1M aqueous hydrochloric acid, and saturated aqueous sodium carbonate, and then dried over magnesium sulfate. The dried solution was concentrated and poured into methanol. The precipitate was collected by filtration and dried under vacuum to obtain PARM (number average molecular weight: 1036), a methacrylic acid ester compound having a polyarylate structure in which both terminal hydroxyl residues derived from the repeating units constituting the polymer structure were directly methacryloylated.

[0118] [Synthesis Example 5: Synthesis of PSM] 85 g of bisphenol A and 30 g of sodium hydroxide were dissolved in toluene, and 40 g of N-methylpyrrolidone (molecular weight: 99.13) was added. The mixture was stirred at 140 °C for 2 hours. 43 g of 4,4'-dichlorodiphenyl sulfone (molecular weight: 287.15) was then added and stirred at 160 °C for 12 hours. After cooling to room temperature, 24 g of methacryloyl chloride was added dropwise and the mixture was stirred at 60 °C for 10 hours. The precipitate formed when methylene chloride was added was removed by filtration, and the filtrate was washed with a 1 wt% aqueous oxalic acid solution and dried over magnesium sulfate. The dried solution was concentrated and poured into methanol. The precipitate was collected by filtration and vacuum dried to obtain PSM (number average molecular weight: 1232), a methacrylate ester compound with a polysulfone structure in which both terminal hydroxyl residues derived from the repeating units constituting the polymer structure were directly methacryloylated.

[0119] [Synthesis Example 6: Synthesis of PCUMA] 80 g of BENEBiOLH S0840H, a polycarbonate diol with a terminal hydroxyl group having an isosorbide skeleton, and 25 mg of dibutyltin dilaurate (molecular weight: 631.57) were dissolved in THF. 50 g of Karenz MOI-EG (molecular weight: 199.20, Showa Denko K.K.) was added dropwise at room temperature, followed by stirring at 40°C for 24 hours. The resulting solution was concentrated, methylene chloride was added, and the mixture was washed with 1 M aqueous hydrochloric acid and dried over magnesium sulfate. The dried solution was concentrated and poured into methanol. The precipitate was collected by filtration and vacuum dried to obtain PCUMA (number average molecular weight: 1200), a methacrylate ester compound with a polycarbonate structure in which alkylene groups, ether bonds, and urethane bonds exist between the hydroxyl residues at both ends derived from the repeating units constituting the polymer structure and the methacryloyl group.

[0120] [Measurement of number average molecular weight] The number average molecular weight (Mn) of the (meth)acrylic acid ester compound (A) was measured using gel permeation chromatography (GPC) as follows. First, at room temperature, each of the compounds synthesized in each of Synthesis Examples 1 to 6 was dissolved in tetrahydrofuran (THF, containing 0.5 mg / mL of BHT) to a concentration of 0.5 mg / mL. The resulting solution was then filtered through a solvent-resistant membrane filter "Myshoridisc" (manufactured by Tosoh Corporation) with a pore size of 0.2 μm to obtain a sample solution. The sample solution was adjusted so that the concentration of components soluble in THF was 0.8 mass%. Measurements were performed using this sample solution under the following conditions. Equipment: High-speed GPC equipment "HLC-8220GPC" [manufactured by Tosoh Corporation] Column: LF-604 (two columns) [Showa Denko K.K.] Eluent:THF Flow rate: 0.6mL / min Oven temperature: 40°C Sample injection volume: 0.020 mL To calculate the molecular weight of the sample, a calibration curve was created using standard polystyrene resins (e.g., trade names "TSK Standard Polystyrene F-850, F-450, F-288, F-128, F-80, F-40, F-20, F-10, F-4, F-2, F-1, A-5000, A-2500, A-1000, A-500" manufactured by Tosoh Corporation) dissolved in THF (containing 0.5 mg / mL BHT) at a concentration of 0.5 mg / mL. 0.2 mL of the solution was injected. The calibration curve was a cubic equation obtained by approximating the curve using the least squares method. The definition of number average molecular weight (Mn) is found in "Fundamentals of Polymer Chemistry" (edited by the Society of Polymer Science, Tokyo Kagaku Dojin, 1978), and can be calculated from the molecular weight distribution curve obtained by GPC. In the case of extremely low molecular weights, the elution peak of the sample may overlap with ghosts derived from the solvent and become unclear (under the above conditions, molecular weights of approximately 400 g / mol or less), but components below this molecular weight were excluded from the calculation to determine the average molecular weight.

[0121] [Production Example 1: Production of polymerizable monomer-containing composition (M1)] A polymerizable monomer-containing composition (M1) was prepared by dissolving 0.2 parts by mass of CQ as a photopolymerization initiator, 0.25 parts by mass of TPO, and 0.3 parts by mass of JJA as a polymerization accelerator in 80 parts by mass of D2.6E and 20 parts by mass of PCIS-3.

[0122] [Production Example 2: Production of polymerizable monomer-containing composition (M2)] A polymerizable monomer-containing composition (M2) was prepared by dissolving 0.2 parts by mass of CQ as a photopolymerization initiator, 0.25 parts by mass of TPO, and 0.3 parts by mass of JJA as a polymerization accelerator in 80 parts by mass of D2.6E and 20 parts by mass of PCN-23.

[0123] [Production Example 3: Production of polymerizable monomer-containing composition (M3)] A polymerizable monomer-containing composition (M3) was prepared by dissolving 0.2 parts by mass of CQ as a photopolymerization initiator, 0.25 parts by mass of TPO, and 0.3 parts by mass of JJA as a polymerization accelerator in 80 parts by mass of D2.6E and 20 parts by mass of PCD-33.

[0124] [Production Example 4: Production of polymerizable monomer-containing composition (M4)] A polymerizable monomer-containing composition (M4) was prepared by dissolving 0.2 parts by mass of CQ as a photopolymerization initiator, 0.25 parts by mass of TPO, and 0.3 parts by mass of JJA as a polymerization accelerator in 80 parts by mass of D2.6E and 20 parts by mass of PARM.

[0125] [Production Example 5: Production of polymerizable monomer-containing composition (M5)] A polymerizable monomer-containing composition (M5) was prepared by dissolving 0.2 parts by mass of CQ as a photopolymerization initiator, 0.25 parts by mass of TPO, and 0.3 parts by mass of JJA as a polymerization accelerator in 80 parts by mass of D2.6E and 20 parts by mass of PSM.

[0126] [Production Example 6: Production of polymerizable monomer-containing composition (M6)] A polymerizable monomer-containing composition (M6) was prepared by dissolving 0.2 parts by mass of CQ as a photopolymerization initiator, 0.25 parts by mass of TPO, and 0.3 parts by mass of JJA as a polymerization accelerator in 80 parts by mass of UDMA and 20 parts by mass of PCIS-3.

[0127] [Production Example 7: Production of polymerizable monomer-containing composition (M7)] A polymerizable monomer-containing composition (M7) was prepared by dissolving 0.2 parts by mass of CQ as a photopolymerization initiator, 0.25 parts by mass of TPO, and 0.3 parts by mass of JJA as a polymerization accelerator in 70 parts by mass of D2.6E, 10 parts by mass of NPG, and 20 parts by mass of PCIS-3.

[0128] [Production Example 8: Production of polymerizable monomer-containing composition (M8)] A polymerizable monomer-containing composition (M8) was prepared by dissolving 0.2 parts by mass of CQ as a photopolymerization initiator, 0.25 parts by mass of TPO, and 0.3 parts by mass of JJA as a polymerization accelerator in 70 parts by mass of D2.6E, 20 parts by mass of PCIS-3, and 10 parts by mass of POBA.

[0129] [Production Example 9: Production of polymerizable monomer-containing composition (M9)] A polymerizable monomer-containing composition (M9) was prepared by dissolving 0.2 parts by mass of CQ as a photopolymerization initiator, 0.25 parts by mass of TPO, and 0.3 parts by mass of JJA as a polymerization accelerator in 70 parts by mass of D2.6E, 20 parts by mass of PCIS-3, and 10 parts by mass of EPPA.

[0130] [Production Example 10: Production of polymerizable monomer-containing composition (M10)] A polymerizable monomer-containing composition (M10) was prepared by dissolving 0.5 parts by mass of THP as a thermal polymerization initiator in 80 parts by mass of D2.6E and 20 parts by mass of PCIS-3.

[0131] [Production Example 11: Production of polymerizable monomer-containing composition (M11)] A polymerizable monomer-containing composition (M11) was prepared by dissolving 0.2 parts by mass of CQ as a photopolymerization initiator, 0.25 parts by mass of TPO, and 0.3 parts by mass of JJA as a polymerization accelerator in 80 parts by mass of D2.6E and 20 parts by mass of PCUMA.

[0132] [Production Example 12: Production of polymerizable monomer-containing composition (M12)] A polymerizable monomer-containing composition (M12) was prepared by dissolving 0.2 parts by mass of CQ as a photopolymerization initiator, 0.25 parts by mass of TPO, and 0.3 parts by mass of JJA as a polymerization accelerator in 80 parts by mass of D2.6E and 20 parts by mass of NPG.

[0133] [Production Example 13: Production of polymerizable monomer-containing composition (M13)] A polymerizable monomer-containing composition (M13) was prepared by dissolving 0.5 parts by mass of THP as a thermal polymerization initiator in 80 parts by mass of D2.6E and 20 parts by mass of PCUMA.

[0134] [Production Example 14: Production of polymerizable monomer-containing composition (M14)] A polymerizable monomer-containing composition (M14) was prepared by dissolving 1.5 parts by mass of BPO as a thermal polymerization initiator in 70 parts by mass of UDMA and 30 parts by mass of TEGDMA.

[0135] The composition of each polymerizable monomer-containing composition is shown in Table 1 below.

[0136] [Table 1]

[0137] [Production Example A: Production of Filler (F1)] 100 parts by mass of NF180 (barium glass (average primary particle size 0.180 μm, manufactured by Schott)) was dispersed in 300 parts by mass of ethanol, and 7 parts by mass of γ-MPS, 0.15 parts by mass of acetic acid, and 5 parts by mass of water were added and stirred at room temperature for 2 hours. The solvent was distilled off under reduced pressure, and the mixture was further surface-treated by drying at 90°C for 3 hours to obtain filler (F1). F1 is inorganic filler (C).

[0138] [Production Example B: Production of Filler (F2)] A mixture of 80 parts by mass of UF2.0 (barium glass (average primary particle size 2.0 μm, manufactured by Schott)) and 20 parts by mass of NF180 (barium glass (average primary particle size 0.180 μm, manufactured by Schott)) was dispersed in 300 parts by mass of ethanol, and 2.25 parts by mass of γ-MPS, 0.15 parts by mass of acetic acid, and 5 parts by mass of water were added and stirred at room temperature for 2 hours. The solvent was distilled off under reduced pressure, and the mixture was further surface-treated by drying at 90°C for 3 hours to obtain filler (F2). F2 is inorganic filler (C).

[0139] [Production Example C: Production of Filler (F3)] A mixture of 90 parts by mass of UF0.7 (barium glass (average primary particle size 0.7 μm, manufactured by Schott)) and 10 parts by mass of Ar130 (fine particle silica (average primary particle size 0.016 μm, manufactured by Nippon Aerosil Co., Ltd.)) was dispersed in 300 parts by mass of ethanol, to which 4 parts by mass of 11-MUS, 0.15 parts by mass of acetic acid, and 5 parts by mass of water were added and stirred at room temperature for 2 hours. The solvent was distilled off under reduced pressure, and the surface was further treated by drying at 90°C for 3 hours to obtain filler (F3). F3 is inorganic filler (C).

[0140] [Production Example D: Production of Filler (F5)] 100 parts by mass of Ox50 (fine particle silica (average primary particle diameter 0.04 μm, manufactured by Nippon Aerosil Co., Ltd.)) was dispersed in 300 parts by mass of ethanol, and 7 parts by mass of γ-MPS, 0.15 parts by mass of acetic acid, and 5 parts by mass of water were added and stirred at room temperature for 2 hours. The solvent was distilled off under reduced pressure, and the surface was further treated by drying at 90°C for 3 hours to obtain filler (F5). F5 is inorganic filler (C).

[0141] The compositions of the fillers (F1 to F5) are shown in Table 2 below.

[0142] [Table 2]

[0143] [Initial mechanical strength and toughness (three-point bending test)] For the dental composite resins, the dental restorative curable compositions of each Example and Comparative Example were vacuum-degassed, filled into a stainless steel mold (dimensions: 2 mm × 2 mm × 25 mm), pressed against each other with glass slides, and cured by irradiating both sides with light using a dental visible light irradiator (PenCure 2000, manufactured by Morita Corporation) for 10 seconds at each point, five points on each side. Five cured samples were prepared for each Example and Comparative Example. After removing the cured samples from the mold, the bending strength and fracture energy of the cured samples were measured using a universal testing machine (manufactured by Shimadzu Corporation, product name "AG-I 100kN") under conditions of a support distance of 20 mm and a crosshead speed of 1 mm / min. The average values of the measured values for each sample were calculated and used as the bending strength (three-point bending strength) and fracture energy. Regarding the dental mill blanks, test pieces (1.2 mm × 4 mm × 15 mm) were cut from the manufactured dental mill blanks using a diamond cutter. Measurements were performed in the same manner as for the dental composite resin samples, except that the support distance when using a universal testing machine was 12 mm and 10 pieces of each cured product were prepared as samples. The bending strength of a dental composite resin was judged to be good if it was 150 MPa or higher, with 180 MPa or higher being even better. The fracture energy of a dental composite resin was judged to be good if it was 13 mJ or higher, with 15 mJ or higher being even better. The bending strength of a dental mill blank was judged to be good if it was 200 MPa or higher, with 240 MPa or higher being even better. The fracture energy of a dental mill blank was judged to be good if it was 30 mJ or higher, with 32 mJ or higher being even better. From the standpoint of mechanical strength and toughness, it is preferable that both the bending strength and fracture energy satisfy the above ranges.

[0144] [Water resistance (3-point bending test)] For the dental composite resin, samples of the cured product of the dental restorative hardenable composition produced in each Example and Comparative Example were immersed in water at 37°C for 30 days, and then the bending strength and fracture energy were measured (n=5), as with the initial mechanical strength. For the dental mill blank, measurements were performed in the same manner as for the dental composite resin, except that n=10. The rate of change (decrease) in bending strength and fracture energy after 30 days of immersion in water at 37°C relative to the initial bending strength and fracture energy was calculated using the following formula. A decrease of 10% or less indicates excellent water resistance, and a decrease of 5% or less indicates even better water resistance. Decrease in bending strength due to immersion (%) = [{initial bending strength (MPa) - bending strength after immersion in water (MPa)} / initial bending strength (MPa)] x 100 Reduction rate of fracture energy due to immersion (%) = [{initial fracture energy (mJ) - fracture energy after immersion in water (mJ)} / initial fracture energy (mJ)] × 100

[0145] [Smoothness durability] For the dental composite resins, the dental restorative curable compositions of each Example and Comparative Example were vacuum degassed and then filled into a stainless steel mold (dimensions: 1.5 mm × 15 mm × 15 mm), pressed against each other with glass slides, and cured by irradiating both sides with light for 90 seconds each in a dental laboratory LED polymerization device (α-Light V, manufactured by Morita Corporation). For the dental mill blanks, test specimens (1.5 mm × 15 mm × 15 mm) were prepared from the dental mill blanks using a diamond cutter. The resulting cured products and test specimens were polished under dry conditions using #1000 sandpaper, #2000 sandpaper, and #3000 sandpaper, in that order, and finally polished with lapping film. The gloss of this test piece was measured before and after a toothbrush abrasion test (toothbrush: "Between Lion" (normal hardness; manufactured by Lion Corporation), toothpaste: "Denta Clear MAX" (manufactured by Lion Corporation), load: 250 g, test solution: distilled water / toothpaste = 90 / 10 (mass%, 50 mL), abrasion times: 40,000 times) using a gloss meter ("VG-2000" manufactured by Nippon Denshoku Industries Co., Ltd.) (n = 2). The gloss was measured as 60° specular gloss (Gs(60°)). The gloss after the toothbrush abrasion test was divided by the gloss before the test to calculate the gloss retention (%), which was used to evaluate the smoothness durability. The gloss retention is preferably 85% or more, more preferably 90% or more, and even more preferably 93% or more.

[0146] [Paste operability (adhesion)] The dental restorative curable compositions prepared in each Example and Comparative Example were vacuum degassed, filled into syringes, and left at 25°C for 24 hours to serve as samples for adhesion tests. The paste was extruded from the syringe and filled into a cup with a capacity of 11 mm lower bottom diameter, 13 mm upper diameter, and 8 mm height. A jig with a 10 mm diameter x 5 mm stainless steel cylinder at its tip was attached to a small benchtop testing machine (Shimadzu Corporation, EZ Test). The bottom of the stainless steel cylinder attached to the cylindrical jig was lightly brought into contact with the surface of the filled paste, and then the jig was lifted at a crosshead speed of 50 mm / min. The maximum stress measured was taken as the adhesion force to the stainless steel plate at 25°C (n=2). The average value was calculated to evaluate the paste's operability. For the evaluation of paste operability, an adhesion force of 1.5 N or less is preferred, with 1.0 N or less being more preferred. On the other hand, an adhesive force of 2.0 N or more is judged to result in poor paste operability when filling with dental instruments.

[0147] [Bubble generation rate of cured product] The dental mill blanks produced were evaluated for the presence or absence of bubbles inside and outside the cured product using a tabletop microfocus X-ray CT system (Shimadzu Corporation, inspeXio SMX-90CT) (n=10). The bubble occurrence rate of the cured product was evaluated based on whether the number of bubbles in the cured product was one or less, and more preferably zero. On the other hand, if there were three or more bubbles, the product was deemed to be of poor quality due to factors such as reduced mechanical strength and poor appearance.

[0148] [Examples 1 to 12, Comparative Examples 1 to 3] (Dental composite resin) The polymerizable monomer-containing compositions (M1 to 9, M11, M12) obtained in the above Production Examples and the fillers (F1 to F4) were mixed and kneaded in the composition ratios shown in Table 3 below to make a homogeneous mixture, which was then vacuum-degassed to prepare paste-like dental restorative hardenable compositions of Examples 1 to 12 and Comparative Examples 1 to 3. Tests were carried out on the prepared dental restorative hardenable compositions. The results are shown in Table 3 below.

[0149] [Table 3]

[0150] As shown in Table 3, the pastes obtained in Examples 1 to 12 all had good workability. Furthermore, the cured products had high bending strength and fracture energy, and showed no decrease in strength when immersed in 37°C water, which simulates the oral cavity, demonstrating excellent water resistance. Furthermore, the cured products showed no decrease in gloss even when abraded by a toothbrush or other device, demonstrating excellent smoothness durability. In contrast, the cured product obtained in Comparative Example 1 had a fair initial fracture energy but significantly poor water resistance. In Comparative Example 1, the PCUMA contained in the compound disclosed in Patent Document 1 has a structure in which alkylene groups and urethane bonds are present between the hydroxyl residues at both ends of the polymer structure derived from the repeating units constituting the polymer structure and the methacryloyl group. This is thought to be due to the relatively low density of the polymer structure, and the presence of urethane bonds, which led to water absorption and reduced water resistance. Furthermore, the cured product obtained in Comparative Example 2 had poor water resistance and very low fracture energy. Furthermore, the cured product obtained in Comparative Example 3 had low mechanical strength, and the paste workability and smoothness durability of the cured product were very poor.

[0151] [Examples 13 to 15, Comparative Examples 4 and 5] (Dental Mill Blanks) The polymerizable monomers (M10, M13, M14) and fillers (F1 to F3, F5) obtained in the above Production Examples were mixed and kneaded in the composition ratios shown in Table 4 below to form a homogeneous mixture, which was then degassed under vacuum to prepare paste-like dental restorative curable compositions for Examples 13 to 15 and Comparative Examples 4 and 5. The dental restorative curable compositions were then poured into a rectangular mold measuring 20 mm x 30 mm x 60 mm and heated at 50°C for 1 hour. Subsequently, the compositions were heat-treated at 150°C for 1 hour while applying a pressure of 1 MPa to obtain cured compositions as dental mill blanks. The resulting cured compositions were then tested. The results are shown in Table 4 below.

[0152] [Table 4]

[0153] All of the cured products obtained in Examples 13 to 15 were free of air bubbles. They also had high bending strength and fracture energy, and showed no decrease in strength when immersed in 37°C water, which simulates the oral cavity, demonstrating excellent water resistance. Furthermore, the cured products showed no decrease in gloss even when abraded by a toothbrush or other tool, demonstrating excellent smoothness durability. In contrast, the cured product obtained in Comparative Example 4 had several bubbles and extremely low water resistance. Furthermore, the cured product obtained in Comparative Example 5 developed cracks during the preparation of the polymerizable monomer-impregnated molded product, and its bending strength and fracture energy were extremely low.

[0154] From the above results, it was found that the dental restorative hardenable composition of the present invention has excellent paste operability, and the hardened product has high mechanical strength and toughness, and is excellent in water resistance and smoothness durability. [Industrial Applicability]

[0155] The dental restorative hardenable composition of the present invention has excellent paste operability, and the cured product has high mechanical strength and toughness, as well as excellent water resistance and smoothness durability. In other words, it is easy to handle and has sufficient mechanical strength to be a substitute for natural teeth, making it suitable for use as a material for repairing tooth defects and caries, particularly as a dental composite resin. Furthermore, the cured product is suitable for use as a dental mill blank.

Claims

1. Selected from the group consisting of polycarbonate, polyarylate, and aromatic polysulfone It has at least one polymer structure, and is derived from a repeating unit constituting the polymer structure. (Meth)acrylic acid esters in which the terminal hydroxyl residues corresponding to the (meth)acrylic acid esters are directly (meth)acryloylated. (A) a (meth)acryloyloxy group-containing ester compound (A); acrylic acid ester compound (B) (excluding the (meth)acrylic acid ester compound (A) (C) an inorganic filler having an average primary particle size of 0.01 to 5 μm, and (D) a polymerization initiator. Including, the polymer structure has a cyclic structure, The (meth)acrylic acid ester compound (A) has a number average molecular weight of 300 to 5,000. the law of nature, The content of the (meth)acrylic acid ester compound (A) in the total amount of polymerizable monomers is and 1 to 40% by mass, The content of the inorganic filler (C) is 50 to 95% of the total amount of the dental restorative hardenable composition. is mass %; The content of the polymerization initiator (D) is 0.001 to 30 parts by mass relative to 100 parts by mass of the polymerizable monomer. parts by weight of a dental restorative hardenable composition.

2. The cyclic structure of the polymer structure is an alicyclic ring, an aromatic ring, and / or a heterocyclic ring. Item 1. A dental restorative hardenable composition according to item 1.

3. The polymer structures each independently contain a carbonate group, an ester group, and a sulfonyl group.

3. The method according to claim 1, wherein the polymerizable compound has three or more functional groups of at least one kind selected from the group consisting of aryl groups and aryl groups.

10. The dental restorative hardenable composition according to claim 1 .

4. The (meth)acrylic acid ester having two or more (meth)acryloyloxy groups. The compound (B) is a difunctional (meth)acrylic acid ester compound and / or a trifunctional or higher functional (meth)acrylic acid ester compound. The dental restoration according to any one of claims 1 to 3, which is a (meth)acrylic acid ester compound. Reusable curable composition.

5. The content of the (meth)acrylic acid ester compound (A) in the total amount of polymerizable monomers is 5. The dental restorative hardenable composition according to claim 1, wherein the content of the hardener is 3 to 35% by mass. thing.

6. A mono(meth)acrylic acid ester compound (E-1) represented by the following general formula (I), and A mono(meth)acrylic acid ester compound (E-2) represented by the following general formula (II): The tooth according to any one of claims 1 to 5, further comprising at least one selected from the group consisting of: Curable composition for medical repair. 【Chemical 1】 【Chemistry 2】 [In the formula, R 1 and R 2 are each independently a group represented by the following general formula (i) or a group represented by the following general formula (ii ) and X is a divalent hydrocarbon group having 1 to 6 carbon atoms or an oxygen atom. 【Chemistry 3】 【Chemistry 4】 (In the formula, R 3 and R 5 are each independently a divalent hydrocarbon group having 1 to 10 carbon atoms, and R 4 and R 6 are each independently a hydrogen atom or a methyl group, and k and l are each independently is an integer from 0 to 6.)

7. 7. The dental restorative hardenable composition according to claim 6, wherein X is an oxygen atom.

8. 8. The dental restorative hardener according to claim 6 or 7, wherein k and l are each independently 0 or 1. chemical composition.

9. The content of the inorganic filler (C) is 55 to 95% of the total amount of the dental restorative hardenable composition.

9. The dental restorative hardenable composition according to claim 1, wherein the hardenable composition is in a concentration of 0.05 wt. %.

10. The tooth composition according to any one of claims 1 to 9, wherein the polymerization initiator (D) includes a photopolymerization initiator. Curable composition for medical repair.

11. The polymerization initiator (D) according to any one of claims 1 to 10, wherein the polymerization initiator (D) comprises a thermal polymerization initiator. A hardenable composition for dental restorations.

12. A dental component comprising the dental restorative hardenable composition according to any one of claims 1 to 11. Posit resin.

13. A dental restoration comprising a hardened product of the dental restorative hardenable composition according to any one of claims 1 to 11. Departmental mill blank.

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