Dental restorative hardening composition

Abstract

This invention provides a curable composition for dental restorations that can produce cured products with an excellent balance of flexural strength, fracture toughness, water resistance, polishability, and opposing tooth wear characteristics. [Solution] A curable dental restorative composition comprising a terminally (meth)acryloyl-modified conjugated diene polymer (A), a (meth)acrylic acid ester compound (B) having two or more (meth)acryloyloxy groups (excluding the terminally (meth)acryloyl-modified conjugated diene polymer (A)), an inorganic filler (C), and a polymerization initiator (D), wherein (A) is, for example, one of the following compounds. JPEG2026122851000018.jpg2874 (In general formula (I), R 1 R is a hydrogen atom or a methyl group, 2 is a single bond or an ethylene group, a is 1 or 2, A 1 A is a polymer of a conjugated diene compound or a hydrogenated product thereof, 1 At least one of the ends of the molecular structure is R 2 They combine.

Description

[Technical Field]

[0001] This invention relates to a curable composition for dental restoration. [Background technology]

[0002] Dental restorative hardening compositions, consisting of polymerizable monomers, fillers, and polymerization initiators, are called dental composite resins and are the most widely used dental materials today for restoring tooth defects and caries. On the other hand, dental mill blanks are materials used to manufacture dental prostheses such as inlays and crowns using CAD / CAM systems, which are designed by computer and manufactured by milling equipment. Demand for these materials has been rapidly increasing in recent years. Dental mill blanks are supplied as blocks of appropriate size in shapes such as rectangular prisms, cylinders, and discs. These blocks are then set in a milling machine and milled to obtain restorations in the shape of tooth crowns or dentition. Various materials have been proposed for dental mill blanks, including glass ceramics, zirconia, titanium, acrylic resin, polymer resin, and composite materials containing inorganic fillers. For example, Patent Document 1 describes a photocurable resin composition containing a specific terminal (meth)acryloyl-modified conjugated diene polymer, a specific (meth)acrylamide compound, and a photopolymerizing agent. Patent Document 2 describes a curable dental restorative composition comprising a (meth)acrylic acid ester compound having at least one polymer structure selected from the group consisting of polycarbonate, polyarylate, and aromatic polysulfone, wherein terminal hydroxyl residues derived from repeating units constituting the polymer structure are directly (meth)acryloylated; a (meth)acrylic acid ester compound having two or more (meth)acryloyloxy groups; an inorganic filler with an average primary particle diameter of 0.01 to 5 μm; and a polymerization initiator. Patent Document 3 describes a dental composition characterized by containing (meth)acrylate as a resin matrix monomer and polymethyl (meth)acrylate particles containing a conjugated diene compound. Furthermore, as a dental mill blank, for example, Patent Document 4 describes a method for manufacturing a dental mill blank, characterized by contacting an inorganic filler molded body, which is obtained by press-molding an inorganic filler, with a polymerizable monomer-containing composition, thereby polymerizing and curing the polymerizable monomer. [Prior art documents] [Patent Documents]

[0003] [Patent Document 1] Japanese Patent Publication No. 2019-001939 [Patent Document 2] International Publication No. 2022 / 145479 [Patent Document 3] Japanese Patent Publication No. 2013-075862 [Patent Document 4] International Publication No. 2014 / 021343 [Overview of the project] [Problems that the invention aims to solve]

[0004] For example, dental composite resins and dental mill blanks require high flexural strength and fracture toughness in the cured product after polymerization, so that the prosthesis does not fracture even under occlusion in the oral cavity; water resistance that can withstand long-term oral restorations; and opposing tooth abrasion characteristics that minimize wear on opposing teeth due to occlusion. Furthermore, when used as a dental composite resin or dental mill blank, it is desirable that the material be easily polished to achieve a glossy finish, and excellent polishability is also required. As a result of the inventors' investigation, it was confirmed that the cured product obtained from the photocurable resin composition described in Patent Document 1 has room for further improvement in terms of flexural strength and fracture toughness when used as a dental composite resin or dental mill blank. Furthermore, it was found that further improvement in polishability is necessary to facilitate the production of gloss through polishing. Furthermore, it was confirmed that there is room for improvement in terms of ease of polishing of the cured product of the dental restorative hardening composition described in Patent Document 2. Furthermore, it was confirmed that the cured product of the dental composition described in Patent Document 3 requires improvement in terms of flexural strength, fracture toughness, water resistance, and ease of polishing. In addition, from the viewpoint of suppressing wear of opposing teeth when loads such as occlusion are applied, there was room for improvement in the opposing tooth wear characteristics as well. Furthermore, it was found that the dental mill blanks obtained by the method for manufacturing dental mill blanks described in Patent Document 4 have room for improvement in terms of water resistance and ease of polishing. Therefore, the present invention aims to provide a curable composition for dental restorations that can produce a cured product with an excellent balance of flexural strength, fracture toughness, water resistance, polishability, and opposing tooth wear characteristics. [Means for solving the problem]

[0005] As a result of diligent research, the inventors have found that the above-mentioned problems can be solved by creating a hardening composition for dental restorations that satisfies specific requirements. In other words, the present invention encompasses the following inventions. [1] A compound comprising a terminal (meth)acryloyl-modified conjugated diene polymer (A), a (meth)acrylic acid ester compound (B) having two or more (meth)acryloyloxy groups (excluding the terminal (meth)acryloyl-modified conjugated diene polymer (A)), an inorganic filler (C), and a polymerization initiator (D), A curable dental restorative composition in which the terminal (meth)acryloyl-modified conjugated diene polymer (A) is at least one selected from the group consisting of terminal (meth)acryloyl-modified conjugated diene polymer (a1) represented by the following general formula (I) and terminal (meth)acryloyl-modified conjugated diene polymer (a2) represented by the following general formula (II). [ka] (In general formula (I), R 1 R is a hydrogen atom or a methyl group, 2 is a single bond or an ethylene group, a is 1 or 2, A 1 A is a polymer of a conjugated diene compound or a hydrogenated product thereof,1 R is bonded to at least one of the ends of the molecular structure of 2 . When a is 2, the two R's present 1 may be the same as each other or different from each other, and the two R's present 2 may be the same as each other or different from each other.) [Chemical formula] (In general formula (II), R 3 is a hydrogen atom or a methyl group, R 4 and R 5 are each independently a divalent group derived from an organic compound, R 6 is a single bond or an ethylene group, b is 1 or 2, and A 2 is a polymer of a conjugated diene compound or a hydrogenated product thereof, and R 2 is bonded to at least one of the ends of the molecular structure of A 6 . When b is 2, the two R's present 3 may be the same as each other or different from each other, the two R's present 4 may be the same as each other or different from each other, the two R's present 5 may be the same as each other or different from each other, and the two R's present 6 may be the same as each other or different from each other.) [2] The dental restorative curable composition according to [1], wherein the content of component (C) is 50 to 95% by mass in 100% by mass of the total amount of the dental restorative curable composition. [3] R 4 and R 5The curable dental restorative composition according to [1] or [2], wherein each of the divalent groups derived from the organic compound represented by is independently a group consisting of an unsubstituted or substituted aliphatic hydrocarbon group having 1 to 20 carbon atoms, an unsubstituted or substituted aliphatic hydrocarbon group having 1 to 20 carbon atoms and having an ether bond, an unsubstituted or substituted alicyclic hydrocarbon group having 3 to 20 carbon atoms that forms a ring, an unsubstituted or substituted aromatic hydrocarbon group having 6 to 20 carbon atoms that forms a ring, an unsubstituted or substituted heterocyclic group having 3 to 20 carbon atoms that forms a ring, or an unsubstituted or substituted aliphatic hydrocarbon group having 1 to 20 carbon atoms, an aliphatic hydrocarbon group having 1 to 20 carbon atoms and having an ether bond, an unsubstituted or substituted alicyclic hydrocarbon group having 3 to 20 carbon atoms that forms a ring, an unsubstituted or substituted aromatic hydrocarbon group having 6 to 20 carbon atoms that forms a ring, and an unsubstituted or substituted heterocyclic group having 3 to 20 carbon atoms that forms a ring. [4] R 4 The dental restorative curable composition according to any one of [1] to [3] above, wherein the group is a divalent group obtained by removing two hydrogen atoms from one selected from the group consisting of ethane, n-propane, isopropane, n-butane, isobutane, sec-butane, n-hexane, benzene, adamantane, diethyl ether, 1,2-diethoxyethane, and diethylene glycol diethyl ether. [5] R 5 The dental restorative curable composition according to any one of [1] to [4] above, wherein the group is a divalent group obtained by removing two hydrogen atoms from one selected from the group consisting of 3,3,5,5-tetramethylcyclohexane, toluene, 4,4'-diphenylmethane, naphthalene, xylene, benzene, 3,3'-dichloro-4,4'-diphenylmethane, n-hexane, 4,4'-dicyclohexylmethane, hydrogenated xylene, triphenylmethane, and hexamethylbenzene. [6] A 1 and A 2The dental restorative curable composition according to any one of [1] to [5] above, wherein each is independently polybutadiene, polyisoprene, a copolymer of butadiene and isoprene, a hydrogenated polybutadiene, a hydrogenated polyisoprene, or a hydrogenated copolymer of butadiene and isoprene. [7] A curable dental restorative composition according to any one of [1] to [6], wherein the number average molecular weight of component (A) is 500 to 100,000. [8] R 1 and R 3 However, each is independently a hydrogen atom, the dental restorative curable composition according to any one of [1] to [7] above. [9] A curable dental restorative composition according to any one of [1] to [8], wherein the content of component (A) is 3 to 33% by mass of the total polymerizable monomers.

[10] A curable dental restorative composition according to any one of [1] to [9], wherein the content of component (B) is 67 to 97% by mass of the total polymerizable monomers.

[11] The content of the polymerizable monomer-containing composition, which is a composition obtained by removing component (C) from the dental restorative curable composition, is 5 to 50% by mass of the total amount of the dental restorative curable composition by mass, and A curable dental restorative composition according to any one of [1] to

[10] , wherein the total content of polymerizable monomers containing at least component (A) and component (B) is 70 to 99.999% by mass of the total amount of the polymerizable monomer-containing composition.

[12] A curable dental restorative composition according to any one of [1] to

[11] , wherein the average primary particle size (D50) of component (C) is 0.001 to 5 μm.

[13] A curable dental restorative composition according to any one of [1] to

[12] , wherein the polymerization initiator (D) comprises a photopolymerization initiator.

[14] A curable dental restorative composition according to any one of [1] to

[13] , wherein the polymerization initiator (D) comprises a thermal polymerization initiator.

[15] A dental restorative curable composition according to any one of [1] to

[14] above, for use with dental composite resin.

[16] A curable dental restorative composition according to any one of [1] to

[14] above, for use in dental mill blanks. [Effects of the Invention]

[0006] According to the present invention, it is possible to provide a curable composition for dental restorations that can produce cured products with an excellent balance of flexural strength, fracture toughness, water resistance, polishability, and opposing tooth wear characteristics. [Modes for carrying out the invention]

[0007] The following description will be based on examples of embodiments of the present invention (hereinafter also referred to as "one aspect of the present invention"). However, the embodiments shown below are illustrative examples for realizing the technical concept of the present invention, and the present invention is not limited to the following description. The present invention also includes embodiments in which any of the matters described herein are arbitrarily selected or combined. In this specification, preferred forms of embodiments are shown, but combinations of two or more individual preferred forms are also preferred forms. Preferred provisions can be arbitrarily selected, and for example, combinations of preferred provisions can be said to be more preferred. In this specification, unless otherwise specified, a numerical range "XX~YY" means "XX or greater and YY or less" (XX represents the lower limit and YY represents the upper limit). For example, when a numerical range is simply written as "10~90", it means the range is 10 or greater and 90 or less. In this specification, the lower and upper limits described in steps for numerical ranges (such as the content of each component, the content of each structural unit, the values ​​and physical properties calculated from them, and the conditions in the manufacturing method) can be combined independently. For example, from a description of the same item as "preferably 10 to 90, more preferably 30 to 60", the "preferred lower limit (10)" and the "more preferred upper limit (60)" can be combined to get "10 to 60". Furthermore, regarding the numerical range, for example, based on the description "preferably 10 to 90, more preferably 30 to 60," the upper limit may not be specifically defined, and only the lower limit may be defined as "10 or more" or "30 or more." Similarly, the lower limit may not be specifically defined, and only the upper limit may be defined as "90 or less" or "60 or less." The same applies when the upper limit of the numerical range is "less than" and when the lower limit is "greater than." Similarly, for example, from the descriptions "preferably 10 or more, more preferably 30 or more" and "preferably 90 or less, more preferably 60 or less" for the same item, the "preferred lower limit (10)" and the "more preferred upper limit (60)" can be combined to get "10 or more and 60 or less". Also, similarly, only the lower limit can be specified as "10 or more" or "30 or more", and similarly, only the upper limit can be specified as "90 or less" or "60 or less". The same applies when the descriptions "or more" and "or less" in the above explanation are written as "greater than" and "less than", respectively. That is, for example, based on the description "preferably more than 10 and less than 90, more preferably 30 or more and 60 or less", the respective upper and lower limits can be combined to get "more than 10 and 60 or less" and "30 or more and less than 90". In this specification, unless otherwise specified, the terms "flexural strength," "fracture toughness," "water resistance," "abrasiveness," and "abrasive properties of opposing teeth" refer to the properties of a cured product obtained from a dental restorative curable composition according to one aspect of the present invention, and each of these properties is specifically evaluated by the method described in the Examples. In this specification, unless otherwise specified, "mechanical strength" refers to "flexural strength" and "fracture toughness." In this specification, unless otherwise specified, the term "crack suppression effect" refers to the effect of suppressing or preventing the occurrence of cracks that occur when a dental restorative curable composition, which is one aspect of the present invention, hardens, and is specifically a property evaluated by the method described in the examples. In this specification, the term "(meth)acrylic" is used to encompass both "methacrylic" and "acrylic." The same applies to similar terms such as "(meth)acrylic acid ester," "(meth)acrylate," and "(meth)acryloyloxy." In this specification, "polymerizable monomer" refers to a compound that can initiate a polymerization reaction and produce a polymer by the action of a polymerization initiator (D) or the like. "Polymerizable monomer" includes terminal (meth)acryloyl-modified conjugated diene polymers (A) (hereinafter also referred to as "component (A)"), and (meth)acrylic acid ester compounds (B) having two or more (meth)acryloyloxy groups (excluding the terminal (meth)acryloyl-modified conjugated diene polymer (A)) (hereinafter also referred to as "component (B)"), as well as any monomer other than components (A) and (B).

[0008] [Hermolytic composition for dental restoratives] A curable composition for dental restoration according to one aspect of the present invention contains a terminally (meth)acryloyl-modified conjugated diene polymer (A), a (meth)acrylic acid ester compound (B) having two or more (meth)acryloyloxy groups (excluding the terminally (meth)acryloyl-modified conjugated diene polymer (A)), an inorganic filler (C) (hereinafter also referred to as "component (C)"), and a polymerization initiator (D) (hereinafter also referred to as "component (D)"), The terminal (meth)acryloyl-modified conjugated diene polymer (A) is at least one selected from the group consisting of a terminal (meth)acryloyl-modified conjugated diene polymer (a1) represented by the following general formula (I) (hereinafter also referred to as "polymer (a1)") and a terminal (meth)acryloyl-modified conjugated diene polymer (a2) represented by the following general formula (II) (hereinafter also referred to as "polymer (a2)").

[0009] [ka] In general formula (I), R 1 R is a hydrogen atom or a methyl group, 2is a single bond or an ethylene group, a is 1 or 2, A 1 A is a polymer of a conjugated diene compound or a hydrogenated product thereof, 1 At least one of the ends of the molecular structure is R 2 They combine. If a is 2, then there are two R 1 These R elements may be identical to each other, or they may be different, and there are two R elements. 2 They may be the same as each other, or they may be different.

[0010] [ka] In general formula (II), R 3 R is a hydrogen atom or a methyl group, 4 and R 5 These are, independently, divalent groups derived from organic compounds, and R 6 b is a single bond or an ethylene group, b is 1 or 2, and A 2 A is a polymer of a conjugated diene compound or a hydrogenated product thereof, 2 R at at least one of the ends of the molecular structure 6 They combine. If b is 2, then there are two R 3 There may be two identical or different Rs. 4 There may be two identical or different Rs. 5 These R elements may be identical to each other, or they may be different, and there are two R elements. 6 They may be the same as each other, or they may be different.

[0011] The reason why the effects of the present invention are obtained with the above configuration is not entirely clear, but the inventors of the present invention surmise the following. Component (A) has a flexible (rubber-like) skeleton derived from conjugated diene compounds such as butadiene, which allows it to relieve stress when subjected to loads such as occlusal forces, exhibiting high fracture toughness and excellent wear characteristics against opposing teeth. In addition, it can suppress crack formation by mitigating shrinkage stress during polymerization. Furthermore, since the skeleton derived from conjugated diene compounds such as butadiene exhibits high hydrophobicity, incorporating component (A) containing these skeletons improves the water resistance of the cured product. Moreover, the skeleton derived from conjugated diene compounds such as butadiene has high toughness and a low glass transition temperature. It is presumed that by combining the terminal (meth)acryloyl-modified conjugated diene polymer (A) containing these skeletons with component (B) that can improve flexural strength and component (C) that can improve surface hardness, flexural strength is improved, and surface irregularities are less likely to occur during polishing, making it easier to achieve a glossy finish. In other words, it is presumed that by creating a dental restorative curable composition that satisfies the above-mentioned configuration, it will be possible to produce a cured product with an excellent balance of flexural strength, fracture toughness, water resistance, polishability, and opposing tooth wear characteristics. The following describes the aforementioned hardening composition for dental restorations.

[0012] <Terminal (meth)acryloyl-modified conjugated diene polymer (A)> Component (A) is at least one selected from the group consisting of a terminal (meth)acryloyl-modified conjugated diene polymer (a1) represented by the general formula (I) and a terminal (meth)acryloyl-modified conjugated diene polymer (a2) represented by the general formula (II). By including component (A) in the aforementioned dental restorative curable composition, it becomes possible to obtain a cured product with excellent fracture toughness, water resistance, and ease of polishing. Furthermore, component (A) can also impart opposing tooth wear characteristics to the cured product, thereby suppressing wear of opposing teeth when loads such as occlusion are applied. Moreover, by using component (A), the occurrence of cracks during polymerization of the dental restorative curable composition can be suppressed, the decrease in flexural strength and fracture toughness associated with crack occurrence can be suppressed, and a cured product with a good appearance can be obtained. The polymers (a1) and (a2) will be described below.

[0013] (Terminal (meth)acryloyl-modified conjugated diene polymer (a1)) The symbols in the general formula (I) relating to polymer (a1) will be explained below. R 1 This is either a hydrogen atom or a methyl group, with a hydrogen atom being preferred. R 2 R is a single bond or an ethylene group, and an ethylene group is preferred. 2 The case where R is a single bond is when, in the general formula (I) above, 2 The oxygen atom (O) and A bonded to it 1 This describes a configuration in which two elements are directly joined by a covalent bond. a is 1 or 2, with 2 being preferred. If a is 2, there are two R 1 These R elements may be identical to each other, or they may be different, and there are two R elements. 2 They may be the same as each other, or they may be different.

[0014] A 1 A is a polymer of a conjugated diene compound or a hydrogenated product thereof, 1 R at at least one of the ends of the molecular structure 2 They combine, preferably A 1 Two R molecules are selected from the ends of the molecular structure. 2 They combine, futurA 1 R is present at at least one of the ends of the main chain of the molecular structure. 2 They combine, and more preferably A 1 Two R molecules are selected from the ends of the main chain of the molecular structure. 2 They combine. In this specification, the term "end of the molecular structure" refers to the entirety of the constituent units (also referred to as "end constituent units" in this specification) at the starting or ending point of polymerization within the structure of a polymer molecule. Furthermore, the term "constituent unit" refers to a unit derived from one molecule of raw material monomer in the polymer. Therefore, "A 1 The state in which R2 is bound to the "end of the molecular structure" is the state in which R 2 However, A 1This indicates that it is bonded to one of the atoms selected from all the atoms present within the terminal structural unit. For example, A 1 If the molecule is polybutadiene or a hydrogenated version thereof, and the terminal structural units of its molecular structure are derived from butadiene monomers, then one of the four carbon atoms present in the terminal structural unit is R 2 This indicates that they are joined together. Furthermore, in this specification, the "A 1 The "main chain of the molecular structure" is A 1 In the molecular structure, this refers to the molecular chain formed by the polymerization of the largest number of raw material monomers, that is, the molecular chain that contains the most constituent units between terminal constituent units. Also, the above "A 1 The term "the end of the main chain of the molecular structure" refers to the A 1 This refers to the entirety of the terminal structural units located at both ends of the main chain of the molecular structure. 1 The end of the main chain of the molecular structure is R 2 The state in which R is bonded is, for example, when the terminal structural unit of the main chain is a structural unit derived from a butadiene monomer, then R is bonded to one of the four carbon atoms present in the terminal structural unit of the main chain. 2 This indicates that they are joined together.

[0015] Examples of the aforementioned conjugated diene compounds include butadiene, isoprene, 2,3-dimethyl-1,3-butadiene, 1,3-pentadiene, 1,3-hexadiene, and farnesene. 1 Preferably, the polymer is polybutadiene, polyisoprene, a copolymer of butadiene and isoprene, a hydrogenated polybutadiene, a hydrogenated polyisoprene, or a hydrogenated copolymer of butadiene and isoprene, more preferably polybutadiene or a hydrogenated polybutadiene. Also, a number of R 2 A that joins 1 It is also the basis of the a-valence.

[0016] A 1With respect to the polymer of the conjugated diene compound relating to the above, the microstructure of the conjugated diene polymer is not particularly limited, but when the conjugated diene is butadiene, the content of its 1,2-bonding units is preferably 1 to 99 mol%, and more preferably 2.5 to 95 mol%. Furthermore, if the conjugated diene compound is isoprene or a mixture of butadiene and isoprene, the total content of 1,2-bonding units and 3,4-bonding units is preferably 1 to 99 mol%, and more preferably 2.5 to 95 mol%.

[0017] Also, A 1 If the compound contains two or more conjugated dienes (e.g., butadiene and isoprene), there are no particular restrictions on their bonding configuration, and they may be random, tapered, completely alternating, partially blocky, blocky, or a combination of two or more of these.

[0018] A 1 The hydrogenated substance in question is usually introduced by producing a conjugated diene polymer and then hydrogenating it. 1 The hydrogenated component (A) of the conjugated diene polymer represented by is A 1 The conjugated diene polymer represented by has higher storage stability than the unhydrogenated component (A). Therefore, component (A) is A 1 When the hydrogenated compound is included as the conjugated diene polymer represented by , the hydrogenation rate is preferably 50 mol% or more, and more preferably 90 mol% or more.

[0019] Note A 1 The hydrogenation rate of the hydrogenated material can be determined by iodine value measurement, infrared spectroscopy, NMR measurement, etc.

[0020] A 1In addition to the conjugated diene polymer, other monomer units may be included, as long as they do not interfere with the objectives and effects of the present invention. Examples of other monomers include structural units derived from styrene, α-methylstyrene, β-methylstyrene, o-methylstyrene, m-methylstyrene, p-methylstyrene, pt-butylstyrene, 2,4-dimethylstyrene, vinylnaphthalene, vinylanthracene, methyl methacrylate, vinyl methyl ether, N-vinylcarbazole, β-pinene, 8,9-p-menthene, dipentene, methylenenorbornene, 2-methylenetetrahydrofuran, and the like. Group A 1 These monomers may be present individually or in combination of two or more.

[0021] A 1 The number-average molecular weight (Mn) is preferably 500 to 100,000, more preferably 750 to 75,000, and even more preferably 1,000 to 50,000. The number-average molecular weight (Mn) referred to here is the polystyrene-based number-average molecular weight (Mn) determined by gel permeation chromatography (GPC) measurement.

[0022] A 1 The molecular weight distribution (weight-average molecular weight (Mw) / number-average molecular weight (Mn): Mw / Mn) is preferably 1.0 to 1.5, more preferably 1.0 to 1.4, and even more preferably 1.0 to 1.3, as this facilitates obtaining an appropriate viscosity for the dental restorative curable composition and high fracture toughness of the resulting cured product. 1 It can be obtained by living anionic polymerization. The weight-average molecular weight (Mw), like the number-average molecular weight (Mn), can be measured by GPC.

[0023] [Typical examples of manufacturing methods for terminal (meth)acryloyl-modified conjugated diene polymers (a1)] The method for producing the terminal (meth)acryloyl-modified conjugated diene polymer (a1) is not particularly limited, and the dental restorative curable composition containing the compound represented by the general formula (I) is included in the scope of the present invention regardless of the production method. However, the terminal (meth)acryloyl-modified conjugated diene polymer (a1) can preferably be produced by the following method.

[0024] (1) After polymerizing a conjugated diene using a dianion initiator such as 1,4-dilithio-1,1,4,4-tetraphenylbutane in a tetrahydrofuran solvent, ethylene oxide is added to convert it to a terminal lithium oxide, and methanol is added to completely stop the reaction to obtain a terminal hydroxyl group-modified conjugated diene polymer represented by the following general formula (III).

[0025] [Chemical formula] (In the general formula (III), R 2 , A 1 and a have the same meanings as the corresponding symbols in the general formula (I), respectively.)

[0026] (2) A 1To produce a terminal (meth)acryloyl-modified conjugated diene polymer (A), that is, a component (A) containing a hydrogenated conjugated diene polymer, in which a polymer of a conjugated diene compound corresponding to the skeleton is hydrogenated, the terminal hydroxyl-modified conjugated diene polymer obtained by the method in (1) above can be hydrogenated, for example, in a saturated hydrocarbon solvent such as cyclohexane, in the presence of a hydrogenation catalyst, usually at a reaction temperature in the range of 20 to 100°C and a hydrogen pressure in the range of 0.1 to 10 MPa. Examples of the hydrogenation catalysts include Raney nickel catalysts; heterogeneous catalysts in which metals such as Pt, Pd, Ru, Rh, and Ni are supported on a carrier such as carbon, alumina, or diatomaceous earth; Ziegler-Natta catalysts consisting of organometallic compounds made of group 9 and 10 metals such as nickel and cobalt, and organoaluminum compounds such as triethylaluminum and triisobutylaluminum, or organolithium compounds; and metallocene catalysts consisting of bis(cyclopentadienyl) compounds of transition metals such as titanium, zirconium, and hafnium, and organometallic compounds containing lithium, sodium, potassium, aluminum, zinc, or magnesium.

[0027] (3) A polymer (a1) represented by the general formula (I) is produced by reacting 1 mole of a terminal hydroxyl group-modified conjugated diene polymer represented by the general formula (III) with a (meth)acrylic acid halide or (meth)acrylic acid anhydride.

[0028] (Terminal (meth)acryloyl-modified conjugated diene polymer (a2)) The symbols in the general formula (II) relating to polymer (a2) will be explained below. R 3 This is either a hydrogen atom or a methyl group, with a hydrogen atom being preferred.

[0029] R 4 and R 5is, independently of each other, a divalent group derived from an organic compound, and the divalent group derived from the organic compound is preferably an unsubstituted or substituted aliphatic hydrocarbon group having 1 to 20 carbon atoms, an unsubstituted or substituted aliphatic hydrocarbon group having 1 to 20 carbon atoms and having an ether bond, an unsubstituted or substituted alicyclic hydrocarbon group having 3 to 20 ring-forming carbon atoms, an unsubstituted or substituted aromatic hydrocarbon group having 6 to 20 ring-forming carbon atoms, an unsubstituted or substituted heterocyclic group having 3 to 20 ring-forming atoms, or an unsubstituted or substituted aliphatic hydrocarbon group having 1 to 20 carbon atoms, an unsubstituted or substituted aliphatic hydrocarbon group having 1 to 20 carbon atoms and having an ether bond, an unsubstituted or substituted alicyclic hydrocarbon group having 3 to 20 ring-forming carbon atoms, an unsubstituted or substituted aromatic hydrocarbon group having 6 to 20 ring-forming carbon atoms, and an unsubstituted or substituted heterocyclic group having 3 to 20 ring-forming atoms, and at least two selected from the group consisting of 2 to 6 are bonded groups. R 4 and R 5 The greater the number of carbon atoms constituting them, the more the flexibility increases, and thus the fracture toughness tends to improve. Also, R 4 and R 5 The smaller the number of carbon atoms constituting them, the higher the density of polar functional groups, resulting in a structure with an increased number of hydrogen bonding points. Furthermore, the higher the density of polymerizable groups per molecular weight, the higher the curability, and thus the flexural strength tends to improve. Therefore, from the viewpoint of achieving a balance between flexural strength and fracture toughness, it is preferable that the number of carbon atoms is as described above.

[0030] In this specification, for example, in the notation "unsubstituted or substituted aliphatic hydrocarbon group having 1 to 20 carbon atoms," "1 to 20 carbon atoms" refers to the number of carbon atoms constituting the unsubstituted aliphatic hydrocarbon group. Therefore, for example, in the case of a methyl group, the number of carbon atoms is 1. Also, even if the methyl group has substituents, for example, substituted methyl groups such as chloromethyl, trifluoromethyl, aminomethyl, and cyanomethyl groups, these substituents all have a hydrogen atom on the methyl group having 1 carbon atom that is replaced by the substituent, so in all cases the number of carbon atoms is 1. Therefore, for example, even if a substituted methyl group as a whole contains 2 carbon atoms, such as the cyanomethyl group, the number of carbon atoms is 1, not 2. The same applies to the notation "aliphatic hydrated carbon groups with 1 to 20 carbon atoms having unsubstituted or substituted ether bonds." For example, a divalent group obtained by removing two hydrogen atoms from diethyl ether has 4 carbon atoms, a divalent group obtained by removing two hydrogen atoms from 1,2-diethoxyethane has 6 carbon atoms, and a divalent group obtained by removing two hydrogen atoms from diethylene glycol diethyl ether has 8 carbon atoms.

[0031] In this specification, "number of ring-forming atoms" refers to the number of atoms constituting the ring structure itself of a compound having a structure in which atoms are bonded in a ring, such as monocyclic compounds, fused rings, and ring aggregates, for example, monocyclic compounds, fused ring compounds, crosslinked compounds, carbocyclic compounds, and heterocyclic compounds. Therefore, the number of hydrogen atoms bonded to the atoms constituting the ring structure itself or atoms included in substituents are not included in the number of ring-forming atoms. For example, a benzene ring has 6 ring-forming atoms, a naphthalene ring has 10 ring-forming atoms, a pyridine ring has 6 ring-forming atoms, and an adamantane ring has 10 ring-forming atoms. Furthermore, for example, the number of hydrogen atoms bonded to a pyridine ring or atoms constituting substituents are not included in the number of ring-forming atoms forming the pyridine ring. For example, when an alkyl group is bonded to a pyridine ring, the number of atoms in the alkyl group is not included in the number of ring-forming atoms of the pyridine ring, so the number of ring-forming atoms of a pyridine ring substituted with the alkyl group is 6. In this specification, "ring-forming carbon number" is the same as "ring-forming atom number" and refers to the number of carbon atoms that constitute the ring structure itself. For example, a benzene ring has 6 ring-forming carbon atoms, a naphthalene ring has 10 ring-forming carbon atoms, and an adamantane ring has 10 ring-forming carbon atoms. Furthermore, for example, the number of hydrogen atoms bonded to a benzene ring, or atoms constituting substituents, are not included in the number of ring-forming carbon atoms that form the benzene ring. For example, when an alkyl group is bonded to a benzene ring, the number of carbon atoms in the alkyl group is not included in the number of ring-forming carbon atoms of the benzene ring, so the number of ring-forming carbon atoms of a benzene ring substituted with the alkyl group is 6.

[0032] The aforementioned R 4 and R 5 Examples of unsubstituted aliphatic hydrocarbon groups having 1 to 20 carbon atoms that can be represented include linear or branched alkylene groups and linear or branched alkenylene groups. Examples of the alkylene group include hexamethylene group, heptamethylene group, octamethylene group, nonamethylene group, decamethylene group, undecamethylene group, dodecamethylene group, tridecamethylene group, tetradecamethylene group, pentadecamethylene group, hexadecamethylene group, heptadecamethylene group, octadecamethylene group, nonadecamethylene group, and eicosamethylene group. Examples of the aforementioned alkenylene group include a 1-hexenylene group, a 2-hexenylene group, and a 3-hexenylene group. Furthermore, the number of carbon atoms in the unsubstituted aliphatic hydrocarbon group having 1 to 20 carbon atoms is preferably 1 to 10, more preferably 1 to 8, even more preferably 1 to 4, and even more preferably 2 to 4, from the viewpoint of achieving an excellent balance between flexural strength and fracture toughness.

[0033] The aforementioned R 4 and R 5Examples of aliphatic hydrocarbon groups having 1 to 20 carbon atoms and having an unsubstituted ether bond that can be represented include alkylene groups having linear or branched ether bonds, alkenylene groups having linear or branched ether bonds, and preferably, a divalent group obtained by removing two hydrogen atoms from one selected from the group consisting of diethyl ether, 1,2-diethoxyethane, and diethylene glycol diethyl ether. Furthermore, the number of carbon atoms in the aliphatic hydrocarbon group having 1 to 20 carbon atoms and having an unsubstituted ether bond is preferably 2 to 14, more preferably 2 to 12, even more preferably 2 to 10, and even more preferably 4 to 8, from the viewpoint of achieving an excellent balance between flexural strength and fracture toughness.

[0034] The aforementioned R 4 and R 5 Examples of unsubstituted alicyclic hydrocarbon groups with 3 to 20 ring-forming carbon atoms that can be represented include cycloalkylene groups and cycloalkenylene groups. Examples of the cycloalkylene group include cyclohexylene, methylcyclohexylene, methylcyclohexylene, dimethylcyclohexylene, cycloheptylene, and cyclooctylene. Examples of the cycloalkenylene group include cyclohexenylene, cycloheptenylene, cyclooctenylene, cyclononenylene, and cyclodecenylene. Furthermore, the number of ring-forming carbon atoms in the unsubstituted alicyclic hydrocarbon group having 3 to 20 ring-forming carbon atoms is preferably 3 to 12, more preferably 3 to 10, even more preferably 4 to 10, and even more preferably 6 to 10, from the viewpoint of achieving an excellent balance between flexural strength and fracture toughness.

[0035] The aforementioned R 4 and R 5 Examples of unsubstituted ring-forming aromatic hydrocarbon groups with 6 to 20 carbon atoms that can be represented include a divalent group obtained by removing two hydrogen atoms from one selected from the group consisting of benzene, naphthalene, anthracene, phenanthrene, and fluorene. 4 and R 5Examples of substituted ring-forming aromatic hydrocarbon groups with 6 to 20 carbon atoms that can be represented include divalent groups obtained by removing two hydrogen atoms from one of the following: toluene, xylene, mesitylene, and biphenyl. Furthermore, the number of ring-forming carbon atoms in the unsubstituted aromatic hydrocarbon group having 6 to 20 carbon atoms is preferably 6 to 18, more preferably 6 to 16, even more preferably 6 to 14, and even more preferably 6 to 10, from the viewpoint of achieving an excellent balance between flexural strength and fracture toughness.

[0036] The aforementioned R 4 and R 5 Each of the aforementioned groups that can be represented by includes the isomers if they exist, insofar as they have the effects of the present invention. Also, as stated above, the R 4 and R 5 Each of these groups may independently consist of 2 to 6 groups of at least two types selected from the group consisting of unsubstituted or substituted C1-C20 aliphatic hydrocarbon groups, unsubstituted or substituted C1-C20 aliphatic hydrocarbon groups having ether bonds, unsubstituted or substituted ring-forming C3-C20 alicyclic hydrocarbon groups, unsubstituted or substituted ring-forming C6-C20 aromatic hydrocarbon groups, and unsubstituted or substituted ring-forming C3-C20 heterocyclic groups. From the viewpoint of achieving an excellent balance between flexural strength and fracture toughness, the number of groups to be bonded is preferably 2 to 4, more preferably 2 or 3.

[0037] The aforementioned R 4 and R 5 In each of the aforementioned groups that can be represented by, the number of substituents (hereinafter also referred to as "any substituents") that each group has when it is "substituted" in the description of "unsubstituted or substituted" is preferably 1 to 10, more preferably 1 to 8, even more preferably 1 to 6, and still more preferably 1 to 4. Furthermore, the R 4 and R 5 If each of the aforementioned groups that can be represented has two or more substituents, the two or more substituents may be the same or they may be different.

[0038] Examples of the aforementioned optional substituents include halogen atoms, substituted or unsubstituted C1-C20 alkyl groups, alicyclic hydrocarbon groups with 3-C20 ring-forming carbon atoms, substituted or unsubstituted aromatic hydrocarbon groups with 6-C20 ring-forming carbon atoms, heterocyclic groups with 3-C20 ring-forming atoms, and *-OR 7 The base represented by *-NR 8 R 9 The base represented by *-C(=O)OR 10 The group represented by *-O(C=O)R 11 The base represented by *-SO3R 12 The base represented by *-PR 13 R 14 Examples include groups represented by , substituted or unsubstituted silyl groups, nitro groups, or cyano groups. R 7 , R 8 , R 9 , R 10 , R 11 , R 12 , R 13 and R 14 Each of these independently represents a hydrogen atom, an alkyl group having 1 to 12 carbon atoms, an alicyclic hydrocarbon group having 3 to 20 ring-forming carbon atoms, or an aromatic hydrocarbon group having 6 to 20 ring-forming carbon atoms. *Each of these symbols independently represents the bonding position between the substituent and the atom to which the substituent is bonded. Furthermore, if these substituents have isomers, the invention includes those isomers insofar as they provide the effects of the present invention.

[0039] Examples of halogen atoms related to the aforementioned arbitrary substituent include fluorine atoms, chlorine atoms, bromine atoms, and iodine atoms, with fluorine atoms or chlorine atoms being preferred.

[0040] The unsubstituted C1-C20 alkyl group in the substituted or unsubstituted C1-C20 alkyl group relating to the aforementioned arbitrary substituent may be a linear alkyl group or a branched alkyl group. That is, the unsubstituted C1-C20 alkyl group is a linear or branched C1-C20 alkyl group. Furthermore, the number of carbon atoms in the substituted or unsubstituted alkyl group having 1 to 20 carbon atoms is preferably 1 to 12, more preferably 1 to 10, even more preferably 1 to 4, and even more preferably 1 or 2. Examples of the unsubstituted alkyl groups having 1 to 20 carbon atoms include methyl groups, ethyl groups, linear or branched propyl groups, linear or branched butyl groups, linear or branched pentyl groups, linear or branched hexyl groups, linear or branched heptyl groups, linear or branched octyl groups, linear or branched nonyl groups, linear or branched decyl groups, linear or branched undecyl groups, linear or branched dodecyl groups, linear or branched tridecyl groups, linear or branched tetradecyl groups, linear or branched pentadecyl groups, linear or branched hexadecyl groups, linear or branched heptadecyl groups, linear or branched octadecyl groups, linear or branched nonadecyl groups, and linear eicosyl groups. Among these alkyl groups, preferred are methyl group, ethyl group, linear or branched propyl group, linear or branched butyl group, linear or branched pentyl group, linear or branched hexyl group, linear or branched heptyl group, linear or branched octyl group, linear or branched nonyl group, and linear or branched decyl group, linear or branched undecyl group, or linear or branched dodecyl group, and more preferably methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, isobutyl group, sec-butyl group, tert-butyl group, n-pentyl group, isopentyl group, sec-pentyl group, neopentyl group, n- The group is a hexyl group, isohexyl group, n-heptyl group, n-octyl group, n-nonyl group, n-decyl group, n-undecyl group, and n-dodecyl group, more preferably a methyl group, ethyl group, propyl group, isopropyl group, n-butyl group, isobutyl group, s-butyl group, and t-butyl group, and even more preferably a methyl group and an ethyl group.

[0041] Furthermore, examples of the substituted C1-C20 alkyl groups include, for example, halogenated alkyl groups substituted with halogen atoms such as chloroalkyl groups and fluoroalkyl groups; aminoalkyl groups substituted with amino groups such as aminomethyl groups; and cyanoalkyl groups substituted with cyano groups such as cyanomethyl groups. Specific examples of the halogenated alkyl group include, for example, chloromethyl group, dichloromethyl group, trichloromethyl group, chloroethyl group, dichloroethyl group, trichloroethyl group, fluoromethyl group, difluoromethyl group, trifluoromethyl group, fluoroethyl group, difluoroethyl group, and trifluoroethyl group.

[0042] The number of ring-forming carbon atoms in the alicyclic hydrocarbon group having 3 to 20 ring-forming carbon atoms related to the aforementioned arbitrary substituent is preferably 3 to 10, more preferably 3 to 8, and even more preferably 3 to 6. Examples of alicyclic hydrocarbon groups having 3 to 20 ring-forming carbon atoms related to the aforementioned arbitrary substituents include cyclopropyl group, cyclobutyl group, cyclopentyl group, cyclohexyl group, cycloheptyl group, cyclooctyl group, cyclononanyl group, cyclodecyl group, cycloundecyl group, cyclododecyl group, decahydronaphthyl group, 1-adamantyl group, 2-adamantyl group, 1-norbornyl group, 2-norbornyl group, cyclotridecyl group, cyclotetradecyl group, cyclopentadecyl group, cyclohexadecyl group, cycloheptadecyl group, cyclooctadecyl group, cyclononadecyl group, and cycloicosyl group. Among these, cyclopentyl group, cyclohexyl group, 1-adamantyl group, and 2-adamantyl group are preferred, more preferably cyclopentyl group and cyclohexyl group, and even more preferably cyclohexyl group.

[0043] The number of ring-forming carbon atoms in the substituted or unsubstituted aromatic hydrocarbon group having 6 to 20 ring-forming carbon atoms related to the aforementioned arbitrary substituent is preferably 6 to 14, more preferably 6 to 10, and even more preferably 6. Examples of unsubstituted ring-forming aromatic hydrocarbon groups having 6 to 20 carbon atoms related to the aforementioned arbitrary substituents include phenyl, indenyl, naphthyl, anthracenyl, fluorenyl, phenantrenyl, pyrenyl, and tetraceryl groups. Among these, phenyl and naphthyl groups are preferred, and phenyl groups are more preferred. Examples of the substituted ring-forming aromatic hydrocarbon groups having 6 to 20 carbon atoms related to the arbitrary substituent include tolyl, xylyl, mesityl, biphenyl, ethylphenyl, isopropylphenyl, and tetramethylphenyl groups.

[0044] The number of ring-forming atoms in the heterocyclic group with 3 to 20 ring-forming atoms related to the aforementioned arbitrary substituent is preferably 3 to 14, more preferably 5 to 13, even more preferably 5 to 10, and even more preferably 5 or 6. Examples of heterocyclic groups having 3 to 20 ring-forming atoms related to the aforementioned arbitrary substituents include furanyl group, thiophenyl group (also called thienyl group), pyrrolyl group, imidazolyl group, oxazolyl group, pyridinyl group, pyrazinyl group, pyrimidinyl group, pyridadinyl group, triazinyl group, benzofuranyl group, benzothiophenyl group (also called benzothienyl group), quinolinyl group (also called quinolyl group), isoquinolinyl group (also called isoquinolyl group), quinazolinyl group, indolyl group, carbazolyl group, dibenzofuranyl group, and dibenzothiophene (also called dibenzothienyl group). Among these, preferred are a furanyl group, a thiophenyl group, a pyrrolyl group, an imidazolyl group, a pyridinyl group, a pyrazinyl group, a pyrimidinyl group, a pyridadinyl group, and a triazinyl group; more preferably a furanyl group, a thiophenyl group, a pyrrolyl group, a pyridinyl group, and a triazinyl group; and even more preferably a thiophenyl group and a pyridinyl group.

[0045] R 7 , R 8 , R 9 , R 10 , R 11 , R 12 , R 13 and R14 Each of these independently represents a hydrogen atom, an unsubstituted C1-C12 alkyl group, an unsubstituted alicyclic hydrocarbon group with 3-20 ring-forming atoms, or an unsubstituted aromatic hydrocarbon group with 6-20 ring-forming atoms.

[0046] The aforementioned *-OR 7 Examples of groups represented by include hydroxyl groups and linear or branched alkoxy groups having 1 to 12 carbon atoms. Examples of linear or branched alkoxy groups having 1 to 12 carbon atoms include methoxy groups, ethoxy groups, n-propoxy groups, isopropoxy groups, n-butoxy groups, n-pentyloxy groups, n-hexyloxy groups, n-heptyloxy groups, n-octyloxy groups, n-decyloxy groups, n-dodecyloxy groups, and cyclohexyloxy groups. Among these, preferred are hydroxyl groups, methoxy groups, ethoxy groups, n-propoxy groups, isopropoxy groups, and n-butoxy groups; more preferably hydroxyl groups, methoxy groups, and ethoxy groups; even more preferably hydroxyl groups and methoxy groups; and even more preferably methoxy groups.

[0047] The aforementioned *-NR 8 R 9 The groups represented by are preferably amino groups, monoalkylamino groups, dialkylamino groups, and diarylamino groups; more preferably amino groups, methylamino groups, dimethylamino groups, diethylamino groups, diisopropylamino groups, and diphenylamino groups; even more preferably dimethylamino groups and diethylamino groups.

[0048] *-C(=O)OR 10 Preferably, the group represented by R 10 is a group represented by a hydrogen atom, a methyl group, or an ethyl group or an isopropyl group, and more preferably the R 10 This is a hydrogen atom or a methyl group. In other words, a carboxyl group represented by *-C(=O)OH or a group represented by *-C(=O)OCH3 is more preferred.

[0049] The above *-O(C=O)R11 Preferably, the group represented by R 11 is a group represented by a methyl group, an ethyl group, or an isopropyl group, and more preferably the R 11 This is a methyl group. In other words, an acetoxy group represented as *-O(C=O)CH3 is more preferred.

[0050] The aforementioned *-SO3R 12 Preferably, the group represented by R 12 is a group represented by a hydrogen atom, a lithium atom, a sodium atom, a potassium atom, a methyl group or an ethyl group, more preferably the R 12 is a group represented by a hydrogen atom, a sodium atom, or a methyl group, more preferably the R 12 This group is represented by a hydrogen atom or a methyl group.

[0051] The aforementioned *-PR 13 R 14 The group represented by the above R 13 and R 14 However, independently of each other, preferably include unsubstituted alkyl groups and unsubstituted aryl groups, more preferably methyl groups, n-butyl groups and phenyl groups, and even more preferably phenyl groups, and even more preferably the R 13 and R 14 However, both groups can be represented by a phenyl group.

[0052] Furthermore, examples of the substituted or unsubstituted silyl groups include alkyl groups such as methyl groups, ethyl groups, linear or branched propyl groups, and linear or branched butyl groups; alkoxy groups such as methoxy groups, ethoxy groups, propoxy groups, and butoxy groups; aryl groups such as phenyl groups; and halogen atoms such as chlorine atoms. For example, a silyl group in which two or three groups selected from the above substituents are substituted on the silicon atom can also be used. Examples of such substituted or unsubstituted silyl groups include silyl groups substituted with one, two, or three substituents selected from the group consisting of silyl groups, unsubstituted alkyl groups, unsubstituted alkoxy groups, and unsubstituted aryl groups. Examples of silyl groups substituted with one, two, or three substituents selected from the group consisting of alkyl groups, alkoxy groups, and aryl groups include trimethylsilyl group, triethylsilyl group, tri-n-propylsilyl group, triisopropylsilyl group, ethyldimethylsilyl group, propyldimethylsilyl group, n-butyldimethylsilyl group, t-butyldimethylsilyl group, diethylisopropylsilyl group, t-butyldiphenylsilyl group, chlorodimethylsilyl group, dichloromethylsilyl group, trimethoxysilyl group, triethoxysilyl group, tripropoxysilyl group, methyldimethoxysilyl group, dimethylmethoxysilyl group, methyldiethoxysilyl group, and dimethylethoxysilyl group. Among these, preferred are trimethoxysilyl group, triethoxysilyl group, tripropoxysilyl group, methyldimethoxysilyl group, dimethylmethoxysilyl group, methyldiethoxysilyl group, and dimethylethoxysilyl group; more preferably trimethoxysilyl group, triethoxysilyl group, and tripropoxysilyl group; and even more preferably trimethoxysilyl group.

[0053] The aforementioned optional substituents are preferably halogen atoms, substituted or unsubstituted linear or branched C1-C20 alkyl groups, ring-forming C3-C20 alicyclic hydrocarbon groups, substituted or unsubstituted ring-forming C6-C20 aromatic hydrocarbon groups, ring-forming C3-C20 heterocyclic groups, and *-OR 7The group is represented by , more preferably a halogen atom, an unsubstituted linear or branched C1-C12 alkyl group, a ring-forming C3-C20 alicyclic hydrocarbon group, an unsubstituted ring-forming C6-C14 aromatic hydrocarbon group, a ring-forming C3-C20 heterocyclic group, and a linear or branched C1-C12 alkoxy group; even more preferably a halogen atom, an unsubstituted linear or branched C1-C12 alkyl group, and a linear or branched C1-C12 alkoxy group; even more preferably a halogen atom and an unsubstituted linear or branched C1-C12 alkyl group; and even more preferably a methyl group and an ethyl group.

[0054] In one embodiment of the present invention, from the viewpoint of having an excellent balance between bending strength and fracture toughness, R 4 However, it is preferable that the group is a divalent group obtained by removing two hydrogen atoms from one selected from the group consisting of ethane, n-propane, isopropane, n-butane, isobutane, sec-butane, n-hexane, benzene, adamantane, diethyl ether, 1,2-diethoxyethane, and diethylene glycol diethyl ether; more preferably that the group is a divalent group obtained by removing two hydrogen atoms from one selected from the group consisting of ethane, n-propane, n-butane, n-hexane, benzene, and diethyl ether; and even more preferably that the group is a divalent group obtained by removing two hydrogen atoms from one selected from the group consisting of ethane, n-propane, and benzene.

[0055] In one embodiment of the present invention, from the viewpoint of having an excellent balance between bending strength and fracture toughness, R 5However, it is preferable that the group is a divalent group obtained by removing two hydrogen atoms from one selected from the group consisting of 3,3,5,5-tetramethylcyclohexane, toluene, 4,4'-diphenylmethane, naphthalene, xylene, benzene, 3,3'-dichloro-4,4'-diphenylmethane, n-hexane, 4,4'-dicyclohexylmethane, hydrogenated xylene, triphenylmethane, and hexamethylbenzene; more preferably that the group is a divalent group obtained by removing two hydrogen atoms from one selected from the group consisting of 3,3,5,5-tetramethylcyclohexane, toluene, 4,4'-diphenylmethane, xylene, benzene, and 4,4'-dicyclohexylmethane; and even more preferably that the group is a divalent group obtained by removing two hydrogen atoms from one selected from the group consisting of 3,3,5,5-tetramethylcyclohexane, toluene, 4,4'-diphenylmethane, and benzene.

[0056] R 6 R is a single bond or an ethylene group, and an ethylene group is preferred. 6 The case where R is a single bond is when, in the general formula (II) above, 6 The oxygen atom (O) and A bonded to it 2 This describes a configuration in which two elements are directly joined by a covalent bond.

[0057] A 2 A is a polymer of a conjugated diene compound or a hydrogenated product thereof, 2 R at at least one of the ends of the molecular structure 6 They combine, preferably A 2 Two R molecules are selected from the ends of the molecular structure. 6 They combine, futurA 2 R is present at at least one of the ends of the main chain of the molecular structure. 6 They combine, and more preferably A 2 Two R molecules are selected from the ends of the main chain of the molecular structure. 6 They combine. Also, "A 2 The end of the molecular structure of R 6 The state in which R is coupled is 6 This indicates that it is bonded to any one of the atoms selected from all the atoms present within the terminal structural unit. For example, A2 If the molecule is polybutadiene or a hydrogenated version thereof, and the terminal structural units of its molecular structure are derived from butadiene monomers, then one of the four carbon atoms present in the terminal structural unit is R 6 This indicates that they are joined together. Furthermore, in this specification, the "A 2 The "main chain of the molecular structure" is A 2 In the molecular structure, this refers to the molecular chain formed by the polymerization of the largest number of raw material monomers, that is, the molecular chain that contains the most constituent units between terminal constituent units. Also, the above "A 2 The term "the end of the main chain of the molecular structure" refers to the A 2 This refers to the entirety of the terminal structural units located at both ends of the main chain of the molecular structure. 2 The end of the main chain of the molecular structure is R 6 The state in which R is bonded is, for example, when the terminal structural unit of the main chain is a structural unit derived from a butadiene monomer, then R is bonded to one of the four carbon atoms present in the terminal structural unit of the main chain. 6 This indicates that they are joined together. A 2 As for A in the general formula (I) mentioned above, 1 Similar polymers or hydrogenated polymers thereof are also examples, and preferred embodiments thereof are also similar. 6 A that joins 2 This is also the basis for the b-valence. A 2 As for A in the general formula (I) mentioned above, 1 Similar polymers or hydrogenated polymers thereof are also examples, and preferred embodiments thereof are also similar. 6 A that joins 2 This is also the basis for the b-valence.

[0058] b is either 1 or 2, with 2 being preferred. If b is 2, there are two R 3 There may be two identical or different Rs. 4 There may be two identical or different Rs. 5These R elements may be identical to each other, or they may be different, and there are two R elements. 6 They may be the same as each other, or they may be different.

[0059] [Typical examples of manufacturing methods for terminal (meth)acryloyl-modified conjugated diene polymers (a2)] The method for producing the terminal (meth)acryloyl-modified conjugated diene polymer (a2) is not particularly limited, and regardless of the method of production, a dental restorative curable composition containing the compound represented by the general formula (II) is included within the scope of the present invention. However, the terminal (meth)acryloyl-modified conjugated diene polymer (a2) can preferably be produced by the following method.

[0060] (4) The following general formula (IV)

[0061] [ka] (In general formula (IV), R 5 R in general formula (II) 5 (It has the same meaning as...) For 1 mole of diisocyanate represented by the following general formula (V)

[0062] [ka] (In general formula (V), R 3 and R 4 Each of these has the same meaning as the corresponding symbol in general formula (II). A hydroxyl group-containing (meth)acrylate represented by isocyanate of general formula (IV) is reacted with one of the isocyanates of general formula (VI) below.

[0063] [ka] (In general formula (VI), R 3 , R 4 and R 5Each of these has the same meaning as the corresponding symbol in general formula (II). This produces an isocyanate group-containing (meth)acrylate represented by [formula].

[0064] (5) The isocyanate group-containing (meth)acrylate represented by general formula (VI) obtained in (4) above is used in the following general formula (VII)

[0065] [ka] (In general formula (VII), R 6 , A 2 , and b each have the same meaning as their corresponding symbols in general formula (II). A polymer (a2) represented by the general formula (II) is produced by reacting it with a terminal hydroxyl group-modified conjugated diene polymer represented by the formula (II).

[0066] The reaction in (4) above is preferably carried out by reacting a hydroxyl group-containing (meth)acrylate represented by general formula (V) with a diisocyanate represented by general formula (IV), using, if necessary, a tertiary amine (e.g., triethylamine, pyridine, 4-N,N-dimethylpyridine, 4-pyrrolidinopyridine), an organotin catalyst (e.g., dibutyltin compounds such as di-n-butyltin dilaurate, dibutyltin diacetate, dibutyltin maleate), a cationic catalyst, and anionic catalyst (e.g., alkyl metals such as tin (Sn), titanium (Ti), aluminum (Al), antimony (Sb), germanium (Ge), zirconium (Zr), zinc (Zn), metal oxides, halides, carboxylates, alkoxides, etc.), thereby smoothly obtaining an isocyanate group-containing (meth)acrylate represented by general formula (VI). The reaction temperature in (4) above is preferably 20 to 80°C.

[0067] The reaction in (5) is preferably carried out by reacting a terminal hydroxyl group-modified conjugated diene polymer represented by general formula (VII) with an isocyanate group-containing (meth)acrylate represented by general formula (VI), similar to (4), thereby smoothly obtaining polymer (a2) represented by general formula (II). The reaction temperature in (5) is preferably 20 to 80°C.

[0068] The number-average molecular weight (Mn) of component (A) is preferably 500 to 100,000, more preferably 750 to 75,000, and even more preferably 1,000 to 50,000. The number-average molecular weight (Mn) referred to here means the polystyrene-converted number-average molecular weight (Mn) determined by gel permeation chromatography (GPC), and is specifically measured by the method described in the examples below.

[0069] The aforementioned curable dental restorative composition may contain only one of polymers (a1) and polymer (a2) as component (A), or it may contain both. In particular, from the viewpoint of having superior fracture toughness and water resistance of the cured product of the curable dental restorative composition, it is preferable to include at least polymer (a2). In one embodiment of the present invention, when component (A) contains polymer (a1), the content of polymer (a1) is more preferably 50 to 100% by mass, even more preferably 80 to 100% by mass, and even more preferably 90 to 100% by mass, and may be 100% by mass, based on 100% by mass of component (A). In one embodiment of the present invention, when component (A) contains polymer (a2), the content of polymer (a2) is more preferably 50 to 100% by mass, even more preferably 80 to 100% by mass, and even more preferably 90 to 100% by mass, and may be 100% by mass, based on 100% by mass of component (A).

[0070] The higher the content of component (A), the more likely it is that fracture toughness, water resistance, polishability, and opposing tooth wear characteristics will be improved. From this viewpoint, the content of component (A) is preferably 3% by mass or more, more preferably 7% by mass or more, and even more preferably 10% by mass or more, out of 100% by mass of the total polymerizable monomers. Furthermore, the above-mentioned dental restorative curable composition is also preferable from the viewpoint that satisfying the content of component (A) will also improve the crack suppression effect. Furthermore, the lower the content of component (A), the more likely it is that the dispersibility of the inorganic filler in the polymerizable monomers, i.e., the miscibility of the dental restorative curable composition will be improved, and the resulting cured product of the dental restorative curable composition will tend to have superior flexural strength. From this viewpoint, the content of component (A) is preferably 33% by mass or less, more preferably 25% by mass or less, and even more preferably 20% by mass or less, out of 100% by mass of the total polymerizable monomers. Furthermore, in one embodiment of the present invention, from the viewpoint of achieving a better balance of flexural strength, fracture toughness, water resistance, polishability, and opposing tooth wear characteristics, the content of component (A) is preferably 3 to 33% by mass, more preferably 7 to 25% by mass, and even more preferably 10 to 20% by mass, of 100% by mass of the total polymerizable monomers. Moreover, the aforementioned dental restorative curable composition is preferable not only because it easily achieves a better balance of the above-mentioned characteristics by satisfying the content of component (A), but also because it easily achieves a better crack suppression effect.

[0071] <(meth)acrylic acid ester compounds (B) having two or more (meth)acryloyloxy groups> The aforementioned dental restorative curable composition, by containing component (B), can impart high flexural strength to the resulting cured product. Component (B) is not particularly limited as long as it is a known (meth)acrylic acid ester compound that exhibits the effects of the present invention and is used in dental composite resins, etc., but examples include a (meth)acrylic acid ester compound (b1) without a cyclic structure (hereinafter also referred to as "compound (b1)") and a (meth)acrylic acid ester compound (b2) having a cyclic structure (hereinafter also referred to as "compound (b2)"). In one embodiment of the present invention, component (B) preferably contains compound (b1) from the viewpoint of achieving a better balance between bending strength, fracture toughness, and ease of polishing. Furthermore, the use of compound (b1) is also preferable from the viewpoint of easily improving the wear characteristics of opposing teeth. In one embodiment of the present invention, from the viewpoint of making it easier to improve water resistance, component (B) preferably contains compound (b2). Component (B) may be used alone or in combination of two or more components.

[0072] Examples of the (meth)acrylic acid ester compound (b1) that does not have the aforementioned cyclic structure include glycerol di(meth)acrylate, ethylene glycol di(meth)acrylate, diethylene glycol di(meth)acrylate, triethylene glycol di(meth)acrylate, propylene glycol di(meth)acrylate, butylene glycol di(meth)acrylate, neopentyl glycol di(meth)acrylate, 1,3-butanediol di(meth)acrylate, 1,5-pentanediol di(meth)acrylate, 1,6-hexanediol di(meth)acrylate, 1,10-decanediol di(meth)acrylate, 1,2-bis(3-methacryloyloxy-2-hydroxypropoxy)ethane, and 2,2,4-trimethylhexamethylenebis(2-carbamoyloxyethyl)di(meth)acrylate. Examples include aliphatic compound-based (meth)acrylic acid ester compounds having two (meth)acryloyloxy groups, such as trimethylolpropane tri(meth)acrylate, trimethylolethane tri(meth)acrylate, trimethylolmethane tri(meth)acrylate, pentaerythritol tri(meth)acrylate, pentaerythritol tetra(meth)acrylate, dipentaerythritol penta(meth)acrylate, N,N-(2,2,4-trimethylhexamethylene)bis[2-(aminocarboxy)propane-1,3-diol]tetra(meth)acrylate, and 1,7-diacryloyloxy-2,2,6,6-tetra(meth)acryloyloxymethyl-4-oxaheptane. Among these, triethylene glycol diacrylate, triethylene glycol dimethacrylate (commonly known as "3G"), neopentyl glycol di(meth)acrylate, 1,2-bis(3-methacryloyloxy-2-hydroxypropoxy)ethane, 2,2,4-trimethylhexamethylenebis(2-carbamoyloxyethyl) dimethacrylate (commonly known as "UDMA"), and 1,10-decanediol dimethacrylate (commonly known as "DD") are preferred. UDMA is more preferred from the viewpoint that when used in combination with component (A), a better balance of flexural strength, fracture toughness, ease of polishing, and opposing tooth wear characteristics is more easily achieved. Compound (b1) may be used alone or in combination of two or more types.

[0073] Examples of the cyclic (meth)acrylic acid ester compound (b2) include (meth)acrylic acid ester compound (b2-1) having an aromatic ring (hereinafter also referred to as "compound (b2-1)"), (meth)acrylic acid ester compound (b2-2) having an alicyclic ring (hereinafter also referred to as "compound (b2-2)"), and (meth)acrylic acid ester compound (b2-3) having a heterocyclic ring (hereinafter also referred to as "compound (b2-3)"). Compound (b2) may be used alone or in combination of two or more types.

[0074] Examples of the aromatic ring in compound (b2-1) include a benzene ring, a naphthalene ring, an anthracene ring, and the like. Examples of the skeleton containing the aromatic ring include a biphenyl skeleton, a benzophenone skeleton, a phenyl ether skeleton, a bisphenol A skeleton, and the like. It is preferable to have a bisphenol A skeleton because it tends to have better flexural strength. Examples of compound (b2-1) include 2,2-bis[4-[3-acryloyloxy-2-hydroxypropoxy]phenyl]propane, 2,2-bis[4-(3-methacryloyloxy-2-hydroxypropoxy)phenyl]propane (commonly known as "Bis-GMA"), 2,2-bis[4-(meth)acryloyloxyethoxyphenyl]propane (commonly known as "Bis-MEPP"), 2,2-bis[4-(meth)acryloyloxypolyethoxyphenyl]propane (for example, one with an average number of added ethoxy groups of 2.6 (commonly known as "D2.6E")), 1,2-bis[3-(meth)acryloyloxy2-hydroxypropoxyphenyl]ethane, and 9,9-bis[4-(2-acryloyloxyethoxy)phenyl]fluorene. Among these, 2,2-bis[4-[3-acryloyloxy-2-hydroxypropoxy]phenyl]propane, 2,2-bis[4-(3-methacryloyloxy-2-hydroxypropoxy)phenyl]propane, 2,2-bis[4-(meth)acryloyloxyethoxyphenyl]propane, and 2,2-bis[4-(meth)acryloyloxypolyethoxyphenyl]propane, which have a bisphenol A skeleton, are preferred from the viewpoint of easily obtaining better flexural strength. Furthermore, 2,2-bis[4-(meth)acryloyloxypolyethoxyphenyl]propane is more preferred from the viewpoint of easily obtaining better water resistance. From a similar viewpoint, 2,2-bis[4-(meth)acryloyloxypolyethoxyphenyl]propane (commonly known as "D2.6E"), which has an average number of moles of ethoxy groups added of 2.6, is even more preferred as the 2,2-bis[4-(meth)acryloyloxypolyethoxyphenyl]propane.

[0075] Examples of alicyclic rings in compound (b2-2) include cyclopentane rings, cyclohexane rings, cycloheptane rings, dicyclodecane rings, tricyclodecane rings, adamantane rings, and isobornyl rings. Examples of compound (b2-2) include 1,4-cyclohexanedimethanol di(meth)acrylate, tricyclodecanedimethanol di(meth)acrylate, adamantyl di(meth)acrylate, and adamantyl tri(meth)acrylate.

[0076] Examples of heterocycles in compound (b2-3) include: heterocycles containing only a nitrogen atom as a heteroatom, such as triazine rings, carbazole rings, pyrrolidine rings, and piperidine rings; heterocycles containing only an oxygen atom as a heteroatom, such as tetrahydrofuran rings, oxane rings, dioxane rings, and dioxolane rings; heterocycles containing both oxygen and nitrogen atoms as heteroatoms, such as morpholine rings; heterocycles containing only a sulfur atom as a heteroatom, such as tetrahydrothiophene rings and tetrahydrothiopyran rings; and heterocycles containing both sulfur and nitrogen atoms as heteroatoms, such as thiazine rings and thiazole rings. Examples of compound (b2-3) include ethoxylated isocyanuric acid tri(meth)acrylate, ε-caprolactone-modified tris(2-(meth)acryloyloxyethyl) isocyanurate, and hydroxypivalaldehyde-modified trimethylolpropanedi(meth)acrylate.

[0077] In one embodiment of the present invention, the content of component (B) is preferably 67% by mass or more, more preferably 75% by mass or more, and even more preferably 80% by mass or more, of 100% by mass of the total polymerizable monomers, from the viewpoint of improving flexural strength. Furthermore, the content of component (B) is preferably 97% by mass or less, more preferably 93% by mass or less, and even more preferably 90% by mass or less, of 100% by mass of the total polymerizable monomers, from the viewpoint of improving fracture toughness, water resistance, ease of polishing, and opposing tooth wear characteristics. Moreover, the dental restorative curable composition is also preferable from the viewpoint of improving crack suppression effect by satisfying the content of component (B). Furthermore, in one embodiment of the present invention, from the viewpoint of achieving a better balance of flexural strength, fracture toughness, water resistance, polishability, and opposing tooth wear characteristics, the content of component (B) is preferably 67 to 97% by mass, more preferably 75 to 93% by mass, and even more preferably 80 to 90% by mass, of the total 100% by mass of polymerizable monomers. Moreover, the above-mentioned dental restorative curable composition is preferable not only because the balance of each of the above-mentioned characteristics is easily improved by satisfying the content of component (B), but also because the crack suppression effect is also easily improved.

[0078] (Total content of components (A) and (B)) From the viewpoint of making the effects of the present invention easier to achieve, the total content of component (A) and component (B) is preferably 90 to 100% by mass, more preferably 95 to 100% by mass, even more preferably 98 to 100% by mass, even more preferably 99 to 100% by mass, even more preferably 99.9 to 100% by mass, and even more preferably 99.99 to 100% by mass, and may be 100% by mass, based on 100% by mass of the total polymerizable monomer.

[0079] (Total content of polymerizable monomers) From the viewpoint of making the effects of the present invention easier to achieve, the total content of the polymerizable monomer, including at least component (A) and component (B), is preferably 70% by mass or more, more preferably 80% by mass or more, even more preferably 90% by mass or more, even more preferably 95% by mass or more, even more preferably 99% by mass or more, and preferably 99.999% by mass or less, more preferably 99.95% by mass or less, even more preferably 99.9% by mass or less, even more preferably 99.7% by mass or less, and even more preferably 99.5% by mass or less. Furthermore, as mentioned above, these progressively defined lower and upper limits can be combined independently. For example, in one embodiment of the present invention, the total content of the polymerizable monomer is preferably 70 to 99.999% by mass, more preferably 80 to 99.95% by mass, even more preferably 90 to 99.9% by mass, even more preferably 95 to 99.7% by mass, and even more preferably 99 to 99.5% by mass, out of 100% by mass of the total amount of the polymerizable monomer-containing composition. In this specification, the term "polymerizable monomer-containing composition" refers to a composition containing polymerizable monomers, wherein the inorganic filler (C) is excluded from the aforementioned dental restorative curable composition.

[0080] (Content of polymerizable monomer-containing composition) From the viewpoint of making the effects of the present invention more easily achieved, the content of the polymerizable monomer-containing composition is preferably 5 to 50% by mass, more preferably 10 to 45% by mass, and even more preferably 15 to 40% by mass, of 100% by mass of the total amount of the dental restorative curable composition.

[0081] <Inorganic filler (C)> As for component (C), any known inorganic filler used as a filling material for dental composite resins can be used, as long as it achieves the effects of the present invention, and it is preferable to use inorganic particles. Examples of the inorganic particles include various types of glass (e.g., silicon dioxide (quartz, quartz glass, silica gel, etc.), silicon-based materials containing boron and / or aluminum along with various heavy metals), alumina, various ceramics, diatomaceous earth, kaolin, clay minerals (montmorillonite, etc.), activated clay, synthetic zeolite, mica, silica, calcium fluoride, ytterbium fluoride, calcium phosphate, barium sulfate, zirconium dioxide (zirconia), titanium dioxide (titania), and hydroxyapatite. In this specification, the term "main component" refers to the component that is present in the highest amount in the total amount of the standard content. Component (C) may be used alone or in combination of two or more components.

[0082] Important physical properties desired in dental materials include transparency and radiopaqueness similar to those of natural teeth. Transparency can be achieved by matching the refractive index of the inorganic filler (C) and the polymer of the polymerizable monomer as closely as possible. On the other hand, radiopaqueness can be imparted by using an inorganic filler (C) containing heavy metal elements such as zirconium, barium, titanium, lanthanum, and strontium (such as an oxide). The refractive index of such heavy metal elements in inorganic fillers is usually high, in the range of 1.5 to 1.65. In one embodiment of the present invention, for example, the refractive index of the cured product of component (B) constituting the polymerizable monomer is usually in the range of 1.5 to 1.6, and the refractive index of the cured product of component (B) is usually in the range of 1.55 to 1.65. Therefore, even when combined with such a high refractive index inorganic filler having radiopaqueness, the refractive index difference can be adjusted to be small, thereby improving the transparency of the resulting dental material.

[0083] Examples of inorganic fillers with high refractive index that can impart the aforementioned X-ray contrast properties include barium borosilicate glass (e.g., "E-3000" from Esstech; "8235", "GM27884", "GM39923", etc. from Schott), strontium boroaluminosilicate glass (e.g., "E-4000" from Esstech; "G018-093", "GM32087", etc. from Schott), lanthanum glass (e.g., "GM31684", etc. from Schott), and fluoroaluminosilicate glass. Examples include glass containing zirconia (for example, Schott's "G018-091" and "G018-117"), glass containing zirconia (for example, Schott's "G018-310" and "G018-159"), glass containing strontium (for example, Schott's "G018-163", "G018-093", and "GM32087"), glass containing zinc oxide (for example, Schott's "G018-161"), and glass containing calcium (for example, Schott's "G018-309").

[0084] There are no particular restrictions on the shape of component (C), and various shapes can be used, such as crushed, plate-like, flaky, fibrous (short fibers, long fibers, etc.), needle-like, whisker-like, or spherical. Component (C) may be a combination of different shapes from the above shapes, as long as it satisfies the requirements of the present invention.

[0085] The average primary particle size (D50) of component (C) is preferably 0.001 to 5 μm. Using component (C) having an average primary particle size (D50) within this range is preferable from the viewpoint of obtaining a dental restorative curable composition with superior polishability of the cured product. From this viewpoint, the average primary particle size (D50) of component (C) is more preferably 0.01 μm or more, even more preferably 0.02 μm or more, even more preferably 0.04 μm or more, and preferably 3 μm or less, and more preferably 2 μm or less. An average primary particle size (D50) greater than 0.001 μm tends to result in good mechanical strength, and a size less than 5 μm tends to result in good polishability. Furthermore, as described above, these lower and upper limits described in stages can be combined independently. For example, in one embodiment of the present invention, the average primary particle size (D50) of component (C) is preferably 0.001 to 5 μm, more preferably 0.01 to 5 μm, even more preferably 0.02 to 3 μm, and even more preferably 0.04 to 2 μm.

[0086] The average primary particle size (D50) of component (C) can be determined by laser diffraction scattering. For example, it can be measured by volume using a laser diffraction particle size distribution analyzer (such as Shimadzu Corporation's "SALD(registered trademark)-7500nano") with a 0.2% aqueous sodium hexametaphosphate solution as the dispersion medium.

[0087] It is preferable that component (C) is pre-surface-treated with a surface treatment agent. By using a surface-treated component (C), the bending strength can be further improved. When using two or more types of components (C), only one of them may be surface-treated, or all of them may be surface-treated. In the latter case, the individually surface-treated components (C) may be mixed, or multiple components (C) may be mixed in advance and then surface-treated together.

[0088] As the surface treatment agent, known surface treatment agents can be used, for example, organometallic compounds such as organosilicon compounds, organotitanium compounds, organozirconium compounds, and organoaluminum compounds, and acidic group-containing organic compounds having at least one acidic group can be used. Examples of the acidic group include phosphoric acid groups, pyrophosphate groups, thiophosphate groups, phosphonic acid groups, sulfonic acid groups, and carboxylic acid groups. When two or more surface treatment agents are used, the surface treatment layer may be a single-layer structure formed from a mixture of the two or more surface treatment agents, or a multi-layer structure formed by stacking multiple single-layer surface treatment layers. Furthermore, there are no particular limitations on the surface treatment method, and known methods can be used.

[0089] The organosilicon compound is R 15 n SiY (4-n) Examples of compounds represented by the formula (wherein R 15 is an unsubstituted or substituted hydrocarbon group having 1 to 12 carbon atoms, Y represents an alkoxy group, acetoxy group, hydroxyl group, halogen atom, or hydrogen atom having 1 to 4 carbon atoms, and n is an integer from 0 to 3, except R 15 (And if there are multiple Y values, they may be the same or different.)

[0090] Specifically, for example, methyltrimethoxysilane, dimethyldimethoxysilane, phenyltrimethoxysilane, diphenyldimethoxysilane, methyltriethoxysilane, dimethyldiethoxysilane, phenyltriethoxysilane, diphenyldiethoxysilane, isobutyltrimethoxysilane, vinyltrimethoxysilane, vinyltrithoxysilane, vinyltris(β-methoxyethoxy)silane, 3,3,3-trifluoropropyltrimethoxysilane, methyl-3,3,3-trifluoro γ-propyldimethoxysilane, 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, tri Examples include methylbromosilane, diethylsilane, vinyltriacetoxysilane, ω-(meth)acryloyloxyalkyltrimethoxysilane [number of carbon atoms between the (meth)acryloyloxy group and silicon atom: 3 to 12, e.g., γ-methacryloyloxypropyltrimethoxysilane], ω-(meth)acryloyloxyalkyltriethoxysilane [number of carbon atoms between the (meth)acryloyloxy group and silicon atom: 3 to 12, e.g., γ-methacryloyloxypropyltriethoxysilane], etc.

[0091] Among these, coupling agents having functional groups that can copolymerize with polymerizable monomers, such as ω-(meth)acryloyloxyalkyltrimethoxysilanes (number of carbon atoms between the (meth)acryloyloxy group and silicon atom: 3 to 12), ω-(meth)acryloyloxyalkyltriethoxysilanes (number of carbon atoms between the (meth)acryloyloxy group and silicon atom: 3 to 12), vinyltrimethoxysilane, vinyltriethoxysilane, vinyltriacetoxysilane, γ-glycidoxypropyltrimethoxysilane, etc., are preferably used.

[0092] Examples of the aforementioned organotitanium compounds include tetramethyl titanate, tetraisopropyl titanate, tetra-n-butyl titanate, butyl titanate dimer, and tetra(2-ethylhexyl) titanate.

[0093] Examples of the aforementioned organozirconium compounds include zirconium isopropoxide, zirconium n-butoxide, zirconium acetylacetonate, and zirconium acetate.

[0094] Examples of the aforementioned organoaluminum compounds include aluminum acetylacetonate and aluminum organic acid salt chelate compounds.

[0095] Regarding the acidic group-containing organic compound having at least one acidic group, for example, an acidic group-containing organic compound containing a phosphate group is 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 Dihydrogen phosphate, 6-(meth)acryloyloxyhexyl dihydrogen phosphate, 7-(meth)acryloyloxyheptyl dihydrogen phosphate, 8-(meth)acryloyloxyoctyl dihydrogen phosphate, 9-(meth)acryloyloxynonyl dihydrogen phosphate, 10-(meth)acryloyloxydecyl dihydrogen phosphate, 11-(meth)acryloyloxyundecyl dihydrogen phosphate, 12-(meth) Acryloyl oxide decyl dihydrogen 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) Examples include acryloyloxyoctyl hydrogen phosphate, bis[9-(meth)acryloyloxynonyl] hydrogen phosphate, bis[10-(meth)acryloyloxydecyl] hydrogen phosphate, 1,3-di(meth)acryloyloxypropyl dihydrogen phosphate, 2-(meth)acryloyloxyethylphenyl hydrogen phosphate, 2-(meth)acryloyloxyethyl-2-bromoethyl hydrogen phosphate, bis[2-(meth)acryloyloxy-(1-hydroxymethyl)ethyl] hydrogen phosphate, as well as acid chlorides thereof, alkali metal salts thereof, and ammonium salts thereof.

[0096] Furthermore, as organic compounds containing acidic groups such as pyrophosphate groups, thiophosphate groups, phosphonic acid groups, sulfonic acid groups, and carboxylic acid groups, those described in International Publication No. 2012 / 042911 can be suitably used, for example.

[0097] The surface treatment agent may be used alone or in combination of two or more types. Furthermore, in order to improve flexural strength by enhancing the chemical bonding between component (C) and the polymerizable monomer, it is more preferable to use an acidic group-containing organic compound having a functional group that can copolymerize with the polymerizable monomer.

[0098] The amount of the surface treatment agent used is not particularly limited, but is preferably 0.1 to 50 parts by mass, more preferably 1 to 25 parts by mass, and even more preferably 1 to 15 parts by mass, per 100 parts by mass of the inorganic filler before surface treatment.

[0099] The content of component (C) is not particularly limited as long as the effects of the present invention are achieved, but from the viewpoint of superior flexural strength and ease of polishing, it is preferably 50 to 95% by mass, more preferably 55 to 90% by mass, and even more preferably 60 to 85% by mass, of 100% by mass of the total amount of the dental restorative curable composition.

[0100] <Polymerization initiator (D)> Examples of component (D) include thermal polymerization initiators, photopolymerization initiators, and redox polymerization initiators. Component (D) may be used alone or in combination of two or more components. Component (D) preferably contains at least one selected from the group consisting of the thermal polymerization initiator and the photopolymerization initiator. In one embodiment of the present invention, component (D) preferably includes the thermal polymerization initiator. In one embodiment of the present invention, when component (D) contains the thermal polymerization initiator, the content of the thermal polymerization initiator is preferably 50 to 100% by mass, more preferably 80 to 100% by mass, even more preferably 90 to 100% by mass, and may also be 100% by mass, of 100% by mass of component (D). In one embodiment of the present invention, component (D) preferably includes the photopolymerization initiator. In one embodiment of the present invention, when component (D) contains the photopolymerization initiator, the content of the photopolymerization initiator is preferably 50 to 100% by mass, more preferably 80 to 100% by mass, and even more preferably 90 to 100% by mass, and may also be 100% by mass, of 100% by mass of component (D). Furthermore, in one embodiment of the present invention, when component (D) contains both the thermal polymerization initiator and the photopolymerization initiator, the total content of the thermal polymerization initiator and the photopolymerization initiator is preferably 50 to 100% by mass, more preferably 80 to 100% by mass, even more preferably 90 to 100% by mass, and may also be 100% by mass, based on 100% by mass of component (D).

[0101] (Thermal polymerization initiator) Examples of the thermal polymerization initiators include organic peroxides and azo compounds. Examples of the aforementioned organic peroxides include ketone peroxides, hydroperoxides, diacyl peroxides, dialkyl peroxides, peroxyketals, peroxyesters, and peroxydicarbonates.

[0102] Examples of the ketone peroxides include methyl ethyl ketone peroxide, methyl isobutyl ketone peroxide, methylcyclohexanone peroxide, and cyclohexanone peroxide. Examples of the aforementioned hydroperoxides include 2,5-dimethylhexane-2,5-dihydroperoxide, diisopropylbenzene hydroperoxide, cumene hydroperoxide, t-butyl hydroperoxide, and 1,1,3,3-tetramethylbutyl hydroperoxide. Examples of the aforementioned diacyl peroxides include acetyl peroxide, isobutyryl peroxide, benzoyl peroxide, decanoyl peroxide, 3,5,5-trimethylhexanoyl peroxide, 2,4-dichlorobenzoyl peroxide, and lauroyl peroxide. Examples of the dialkylperoxides include di-t-butylperoxide, dicumylperoxide, t-butylcumylperoxide, 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-hexine. 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. Examples of the peroxyesters include α-cumylperoxyneodecanoate, t-butylperoxyneodecanoate, t-butylperoxypivalate, 2,2,4-trimethylpentylperoxy-2-ethylhexanoate, t-amylperoxy-2-ethylhexanoate, t-butylperoxy-2-ethylhexanoate, di-t-butylperoxyisophthalate, di-t-butylperoxyhexahydroterephthalate, t-butylperoxy-3,3,5-trimethylhexanoate, t-butylperoxyacetate, t-butylperoxybenzoate, and t-butylperoxymalelic acid. Examples of the peroxydicarbonates include di-3-methoxyperoxydicarbonate, di-2-ethylhexylperoxydicarbonate, bis(4-t-butylcyclohexyl)peroxydicarbonate, diisopropylperoxydicarbonate, di-n-propylperoxydicarbonate, di-2-ethoxyethylperoxydicarbonate, and diallylperoxydicarbonate.

[0103] Among these organic peroxides, diacyl peroxides and hydroperoxides are preferred from the viewpoint of safety and storage stability, and hydroperoxides are more preferred from the viewpoint of improving the polymerization rate and making the resulting polymers more mechanically strong.

[0104] Examples of the aforementioned azo compounds include 2,2'-azobis(isobutyronitrile), 2,2'-azobis(2,4-dimethylvaleronitrile), 4,4'-azobis(4-cyanovaleric acid), 1,1'-azobis(cyclohexane-1-carbonnitrile), dimethyl-2,2'-azobis(isobutyrate), and 2,2'-azobis(2-amidinopropane)dihydrochloride.

[0105] (Photopolymerization initiator) Examples of the photopolymerization initiators include (bis)acylphosphine oxides, α-diketones, and coumarins.

[0106] Examples of the (bis)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.

[0107] Examples of the (bis)acylphosphine 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.

[0108] 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.

[0109] Examples of the α-diketones include diacetyl, benzyl, camphorquinone, 2,3-pentadione, 2,3-octadione, 9,10-phenanthrenequinone, 4,4'-oxybenzyl, and acenaphthenequinone. Among these, camphorquinone is preferred.

[0110] The aforementioned coumarins include 3,3'-carbonylbis(7-diethylaminocoumarin), 3-(4-methoxybenzoyl)coumarin, 3-thienoylcoumarin, 3-benzoyl-5,7-dimethoxycoumarin, 3-benzoyl-7-methoxycoumarin, 3-benzoyl-6-methoxycoumarin, 3-benzoyl-8-methoxycoumarin, 3-benzoylcoumarin, 7-methoxy-3-(p-nitrobenzoyl)coumarin, 3-(p-nitrobenzoyl)coumarin, 3,5-Carbonylbis(7-methoxycoumarin), 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 Benzyl)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-dimethylbenzothiazole-2-ylidene)acetyl]coumarin, 3-[(1-methylnaphtho[1,2-d]thiazole-2-ylidene)acetyl]coumarin, 3,3'-carbonylbis(6-methoxycoumarin), 3,3'-carbonylbis(7-acetoxycoumarin), 3,3'-Carbonylbis(7-dimethylaminocoumarin), 3-(2-benzothiazoyl)-7-(diethylamino)coumarin, 3-(2-benzothiazoyl)-7-(dibutylamino)coumarin, 3-(2-benzoimidazoyl)-7-(diethylamino)coumarin, 3-(2-benzothiazoyl)-7-(dioctylamino)coumarin, 3-acetyl-7-(dimethylamino)coumarin, 3,3'-Carbonylbis(7-dibutylaminocoumarin), 3,3'-Carbonyl-7-diethylaminocoumarin-7'-bis(butoxyethyl)amino Examples of compounds described in Japanese Patent Publication No. 9-3109 and Japanese Patent Publication No. 10-245525 include coumarin, 10-[3-[4-(dimethylamino)phenyl]-1-oxo-2-propenyl]-2,3,6,7-tetrahydro-1,1,7,7-tetramethyl1H,5H,11H-[1]benzopyrano[6,7,8-ij]quinoridine-11one, and 10-(2-benzothiazoyl)-2,3,6,7-tetrahydro-1,1,7,7-tetramethyl1H,5H,11H-[1]benzopyrano[6,7,8-ij]quinoridine-11one.

[0111] Among the aforementioned coumarin compounds, 3,3'-carbonylbis(7-diethylaminocoumarin) and 3,3'-carbonylbis(7-dibutylaminocoumarin) are preferred.

[0112] Among the aforementioned 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 restorative curing compositions.

[0113] Furthermore, the aforementioned photopolymerization initiator can, if necessary, be combined with a polymerization accelerator to enable more efficient and faster photopolymerization. Suitable polymerization accelerators for use in combination with photopolymerization initiators include, for example, tertiary amines, aldehydes, compounds having thiol groups, sulfinic acid, and sulfinate salts.

[0114] Examples of the tertiary amines include N,N-dimethylaniline, N,N-dimethylp-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-diiso Examples 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.

[0115] Examples of the aforementioned aldehydes include dimethylaminobenzaldehyde and terephthalaldehyde. Examples of compounds having the thiol group include 2-mercaptobenzoxazole, decanethiol, 3-mercaptopropyltrimethoxysilane, and thiobenzoic acid.

[0116] Examples of the aforementioned sulfinic acid and sulfinate 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 include calcium trimethylbenzenesulfinate, 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. The polymerization accelerator used in combination with the aforementioned photopolymerization initiator may be used alone or in combination of two or more types.

[0117] (Redox polymerization initiator) The aforementioned redox polymerization initiator contains an oxidizing agent and a reducing agent, and organic peroxides and amines; organic peroxides, amines and sulfinic acid (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.

[0118] Examples of oxidizing agents for the redox polymerization initiator include organic peroxides. The organic peroxide used as the oxidizing agent for the redox polymerization initiator is not particularly limited, and known peroxides can be used. Specifically, examples include the organic peroxides exemplified in the thermal polymerization initiator. Among the aforementioned organic peroxides, diacyl peroxides are preferred from the perspective of the overall balance of safety, storage stability, and radical generation ability, and benzoyl peroxides are more preferred among them.

[0119] As the reducing agent for the redox polymerization initiator, for example, a tertiary aromatic amine that does not have an electron-withdrawing group on its aromatic ring is used. Examples of tertiary aromatic amines that do not have an electron-withdrawing group on their 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, and N,N-bis(2-hydroxy) Examples include ethyl)-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.

[0120] The aforementioned redox polymerization initiator may be used in combination with a polymerization accelerator as needed. The polymerization accelerator used in combination with the aforementioned redox polymerization initiator (hereinafter also referred to as the "polymerization accelerator for the redox polymerization initiator") can be selected from polymerization accelerators used in general industry, and among them, polymerization accelerators used in dental applications are preferred. Specifically, examples include amines, sulfinic acid and sulfinate salts, copper compounds, and tin compounds. The polymerization accelerator for the redox polymerization initiator may be used alone or in combination of two or more types.

[0121] The amines used as polymerization accelerators for the aforementioned redox polymerization initiators can be divided into aliphatic amines and aromatic amines having an electron-withdrawing group on the aromatic ring. Examples of the aliphatic amines include primary aliphatic amines such as n-butylamine, n-hexylamine, and n-octylamine; secondary aliphatic amines such as diisopropylamine, dibutylamine, and N-methylethanolamine; and tertiary aliphatic amines such as N-methyldiethanolamine, N-ethyldiethanolamine, Nn-butyldiethanolamine, N-lauryldiethanolamine, 2-(dimethylamino)ethyl methacrylate, N-methyldiethanolamine dimethacrylate, N-ethyldiethanolamine dimethacrylate, triethanolamine monomethacrylate, triethanolamine dimethacrylate, triethanolamine trimethacrylate, triethanolamine, trimethylamine, triethylamine, and tributylamine. Among these, tertiary aliphatic amines are preferred from the viewpoint of curability and storage stability of the dental restorative curable composition, and at least one selected from N-methyldiethanolamine and triethanolamine is more preferred.

[0122] Examples of aromatic amines having an electron-withdrawing group on the aromatic ring that can be used as polymerization accelerators for the redox polymerization initiator include tertiary aromatic amines having an electron-withdrawing group on the aromatic ring. Examples of tertiary aromatic amines having an electron-withdrawing group on the aromatic ring that can be used as polymerization accelerators for the redox polymerization initiator 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, benzophenone, and butyl 4-(N,N-dimethylamino)benzoate. Among these, at least one selected from the group consisting of N,N-di(2-hydroxyethyl)-p-toluidine, ethyl 4-(N,N-dimethylamino)benzoate, 4-(N,N-dimethylaminobenzoic acid)n-butoxyethyl, and 4-(N,N-dimethylamino)benzophenone is preferably used from the viewpoint of imparting excellent curability to dental restorative hardening compositions.

[0123] Examples of sulfinic acid and sulfinate salts used as polymerization accelerators for the redox polymerization initiator include those exemplified as polymerization accelerators for the photopolymerization initiator, with sodium benzenesulfinate, sodium p-toluenesulfinate, and sodium 2,4,6-triisopropylbenzenesulfinate being preferred.

[0124] Suitable copper compounds used as polymerization accelerators for the aforementioned redox polymerization initiators include, for example, copper acetylacetone, cupric acetate, copper oleate, cupric chloride, and cupric bromide.

[0125] Examples of tin compounds used as polymerization accelerators for the aforementioned redox polymerization initiators include di-n-butyltin dimaleate, di-n-octyltin dimaleate, di-n-octyltin dilaurate, and di-n-butyltin dilaurate. Preferred examples of tin compounds are di-n-octyltin dilaurate and di-n-butyltin dilaurate.

[0126] Among the polymerization initiators mentioned above, for example, with regard to dental composite resins, it is preferable to use the photopolymerization initiator due to its ease of curing in the oral cavity, while with regard to dental mill blanks, it is preferable to use the thermal polymerization initiator because it increases the degree of polymerization and improves strength.

[0127] The content of component (D) is not particularly limited as long as the effects of the present invention are achieved, but from the viewpoint of the curability of the resulting dental restorative curable composition, it is preferably 0.001 to 30 parts by mass per 100 parts by mass of the total polymerizable monomers. When the content of component (D) is 0.001 parts by mass or more per 100 parts by mass of the total polymerizable monomers, polymerization proceeds sufficiently and there is no risk of a decrease in mechanical strength, and it is more preferably 0.05 parts by mass or more, and even more preferably 0.1 parts by mass or more. On the other hand, when the content of component (D) is 30 parts by mass or less per 100 parts by mass of the total polymerizable monomers, sufficient mechanical strength can be obtained even if the polymerization performance of the polymerization initiator itself is low, and there is no risk of precipitation from the dental restorative curable composition, and it is more preferably 20 parts by mass or less, even more preferably 10 parts by mass or less, even more preferably 5 parts by mass or less, and even more preferably 2.0 parts by mass or less. Furthermore, as described above, these lower and upper limits described in stages can be combined independently. For example, in one embodiment of the present invention, the content of component (D) is preferably 0.001 to 30 parts by mass, more preferably 0.05 to 20 parts by mass, even more preferably 0.1 to 10 parts by mass, even more preferably 0.1 to 5 parts by mass, even more preferably 0.1 to 2.0 parts by mass, even more preferably 0.1 to 1.0 parts by mass, and even more preferably 0.1 to 0.5 parts by mass, based on 100 parts by mass of the total polymerizable monomers.

[0128] Furthermore, when using the polymerization accelerator, the content of the polymerization accelerator is not particularly limited as long as the effects of the present invention are achieved, but is preferably 0.001 to 30 parts by mass, more preferably 0.01 to 20 parts by mass, more preferably 0.05 to 20 parts by mass, even more preferably 0.1 to 10 parts by mass, even more preferably 0.1 to 5 parts by mass, even more preferably 0.1 to 2.0 parts by mass, even more preferably 0.1 to 1.0 parts by mass, and even more preferably 0.1 to 0.5 parts by mass per 100 parts by mass of the total polymerizable monomers.

[0129] (Total content of ingredients (A), (B), and (D)) From the viewpoint of making the effects of the present invention easier to achieve, the total content of component (A), component (B), and component (D) is preferably 70.001% by mass or more, more preferably 80% by mass or more, even more preferably 90% by mass or more, even more preferably 95% by mass or more, even more preferably 99% by mass or more, and 100% by mass or less, preferably 99.99% by mass or less, more preferably 99.95% by mass or less, even more preferably 99.9% by mass or less, even more preferably 99.8% by mass or less, and may also be 100% by mass. Furthermore, as described above, these progressively defined lower and upper limits can be combined independently. For example, in one embodiment of the present invention, the total content of component (A), component (B), and component (D) is preferably 70.001 to 100% by mass, more preferably 80 to 99.99% by mass, even more preferably 90 to 99.95% by mass, even more preferably 95 to 99.9% by mass, even more preferably 99 to 99.8% by mass, and may also be 100% by mass, based on 100% by mass of the total amount of the polymerizable monomer-containing composition. Here, regarding the respective content of components (A), (B), and (D) mentioned above, each can take on the respective content as described above, and their respective preferred ranges can be combined independently. However, when the selected content is combined, it is obvious that the total content of components (A), (B), and (D) in 100% by mass of the total amount of the polymerizable monomer-containing composition will not exceed 100% by mass. In other words, as stated above, the total content of components (A), (B), and (D) is 100% by mass or less in 100% by mass of the total amount of the polymerizable monomer-containing composition. Similarly, in one embodiment of the present invention, the polymerization accelerator is further included. When the polymerization accelerator is included, the total content of component (A), component (B), component (D), and the polymerization accelerator is 100% by mass or less of the total amount of the polymerizable monomer-containing composition.

[0130] <Other ingredients> In addition to components (A) to (D) and the polymerization accelerator which may be optionally included, the aforementioned dental restorative curable composition may contain other components as needed, insofar as the effects of the present invention are achieved. Examples of such other components include pH adjusters, ultraviolet absorbers, antioxidants, colorants, pigments, antibacterial agents, X-ray contrast agents, thickeners, and fluorescent agents. The aforementioned other components may be used individually or in combination of two or more.

[0131] The aforementioned pigment can be any known pigment used in dental restorative curable compositions, without any limitations. The aforementioned pigment can be at least one selected from inorganic pigments and organic pigments. Examples of the inorganic pigments include chromates such as lead yellow, zinc yellow, and barium yellow; ferrocyanides such as Prussian 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 oxide, 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 the aforementioned organic pigments include nitro pigments such as naphthol green B and naphthol green Y; nitro pigments such as naphthol S and lysol fast yellow 2G; insoluble azo pigments such as permanent red 4R, brilliant fast scarlet, Hansa yellow, and benzidine yellow; poorly soluble azo pigments such as lysol 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. The aforementioned pigments may be appropriately selected according to the desired color tone, and one type may be used alone, or two or more types may be used in combination.

[0132] When the curable dental restorative composition contains a pigment, the pigment content in the curable dental restorative composition is not particularly limited as it is adjusted appropriately according to the desired color tone, but is preferably 0.000001% by mass or more, more preferably 0.00001% by mass or more, and preferably 5% by mass or less, more preferably 1% by mass or less, and even more preferably 0.5% by mass or less, per 100% by mass of the curable dental restorative composition. Furthermore, the pigment content is preferably 0.000001 to 5% by mass, more preferably 0.00001 to 1% by mass, and even more preferably 0.00001 to 0.5% by mass, per 100% by mass of the curable dental restorative composition.

[0133] Furthermore, if the dental restorative curable composition contains other components, there are no particular limitations on the total content of the other components as long as the effects of the present invention are achieved, and any amount that yields the necessary effects may be used. For example, the total content of the other components is preferably 0.000001 to 5% by mass, more preferably 0.00001 to 1% by mass, and even more preferably 0.00001 to 0.5% by mass, per 100% by mass of the dental restorative curable composition. Here, if the dental restorative curable composition contains other components, as described above, the respective contents of components (A), (B), and (D), as well as the other components, can be independently set to the aforementioned quantities, and their respective preferred ranges can be independently combined. However, it is obvious that when the selected contents are combined, the total content of components (A), (B), and (D), as well as the other components, does not exceed 100% by mass of the total amount of the polymerizable monomer-containing composition. In other words, if the dental restorative curable composition contains other components, the total content of components (A), (B), and (D), as well as the other components, is 100% by mass or less of the total amount of the polymerizable monomer-containing composition. Similarly, in one embodiment of the present invention, the polymerization accelerator is further included. When the polymerization accelerator is included, the total content of component (A), component (B), component (D), the polymerization accelerator, and other components is 100% by mass or less of the total amount of the polymerizable monomer-containing composition.

[0134] <Method for producing a hardening composition for dental restorations> Examples of methods for producing the aforementioned dental restorative curable composition include a manufacturing method comprising the following steps (i) to (ii) in this order.

[0135] Process (i): Mixing process The kneading process involves mixing the ingredients. In this process, ingredients (A), (B), and (D) are added to a kneading machine container to prepare a polymerizable monomer-containing composition. Then, ingredient (C) is added and kneading is performed to produce a paste-like composition. The method of mixing each component in the mixing process is not particularly limited as long as it achieves the effects of the present invention, and known methods can be used. However, from the viewpoint of shortening the mixing time and preventing variations in the degree of dispersion of each component in the paste-like composition, it is preferable to mix while heating. The mixing temperature is preferably 40 to 60°C. A temperature of 40°C or higher is preferable because it sufficiently shortens the mixing time, and a temperature of 60°C or lower is preferable because it prevents polymerization hardening and deterioration of the paste-like composition during mixing. In addition, vacuum degassing can be performed during mixing as needed. At this time, the degree of vacuum is not particularly limited, but for example, in order to efficiently remove air bubbles, a vacuum degree of 5 to 200 Torr is preferable. Furthermore, it is preferable to knead the above-mentioned components in a dark place or under yellow light.

[0136] Step (ii): Defoaming step The defoaming step is a process in which defoaming is performed. After putting the paste-like composition obtained in step (i) into the defoaming machine container, defoaming is performed by removing air bubbles from inside the paste-like composition by reducing the pressure and pushing it out of the container under pressure. The defoaming conditions are not particularly limited, but in order to efficiently remove air bubbles and to suppress the separation of the polymerizable monomer-containing composition containing components (A), (B), and (D) from component (C), the vacuum level is preferably 5 to 200 Torr, and the reduced pressure time is preferably 3 to 30 minutes. In addition, the pressure when pushing out of the defoaming machine container is preferably 0.5 to 5 MPa, and the pressurizing time is preferably 3 to 30 minutes. Furthermore, heat treatment can be performed during defoaming as needed. The temperature during defoaming is not particularly limited, but in order to efficiently remove air bubbles, 40 to 60°C is preferred. Furthermore, it is preferable to perform the degassing process in a dark place or under yellow light. The curable dental restorative composition obtained by this manufacturing method is the same as that described in the section on curable dental restorative composition, which is one aspect of the present invention, and its preferred embodiment is also the same.

[0137] [Dental Composite Resin] A dental composite resin according to one aspect of the present invention includes the aforementioned dental restorative curable composition. The dental composite resin contains the dental restorative curable composition, resulting in a cured product that exhibits excellent flexural strength, fracture toughness, water resistance, polishability, and opposing tooth abrasion characteristics. Therefore, the curable dental restorative composition according to one aspect of the present invention can be suitably used with dental composite resins. Specifically, as the curable dental restorative composition according to one aspect of the present invention, a curable dental restorative composition for dental composite resins is preferably mentioned. Furthermore, one aspect of the present invention is the use of the dental restorative curable composition, which is one aspect of the present invention, as a dental composite resin. The dental curable composition and its manufacturing method are the same as those described in the section on the dental restorative curable composition, which is one aspect of the present invention, and the preferred embodiments are also the same. Furthermore, the manufacturing method for the dental composite resin can also be the same as the manufacturing method that includes steps (i) to (ii) in this order.

[0138] The dental composite resin preferably contains the dental restorative curable composition as an active ingredient, and more preferably has the dental restorative curable composition as its main component. Here, "containing the dental restorative curable composition as an active ingredient" means that the effect of the cured product of the dental composite resin being excellent in flexural strength, fracture toughness, water resistance, polishability, and opposing tooth wear characteristics is derived from the dental restorative curable composition. The content of the dental restorative curable composition in the dental composite resin is preferably 50 to 100% by mass, more preferably 60 to 100% by mass, even more preferably 70 to 100% by mass, even more preferably 80 to 100% by mass, and even more preferably 90 to 100% by mass, based on 100% by mass of the total amount of the dental composite resin, and may also be 100% by mass.

[0139] [Dental mill blanks] A dental mill blank according to one aspect of the present invention is obtained by curing the aforementioned dental restorative curable composition. Because the dental mill blank is a cured product obtained by curing the dental restorative curable composition, it exhibits excellent flexural strength, fracture toughness, water resistance, polishability, and opposing tooth wear characteristics. Furthermore, since the dental restorative curable composition also has excellent crack suppression effects, the dental mill blank, which is one form of its cured product, also suppresses crack formation and has a good appearance. Therefore, the curable dental restorative composition according to one aspect of the present invention can be suitably used for dental mill blanks. In other words, one preferred aspect of the curable dental restorative composition is a curable dental restorative composition for use in dental mill blanks. Furthermore, one aspect of the present invention is the use of the dental restorative curable composition according to one aspect of the present invention for dental mill blanks.

[0140] The dental mill blank preferably contains a component derived from the dental restorative hardening composition as an active ingredient, and more preferably has a component derived from the dental restorative hardening composition as its main component. Here, "containing a component derived from the dental restorative hardening composition as an active ingredient" means that the dental mill blank's excellent flexural strength, fracture toughness, water resistance, ease of polishing, and opposing tooth wear characteristics are derived from the dental restorative hardening composition. Furthermore, the "component derived from the dental restorative curable composition" refers to a component obtained by curing the dental restorative curable composition, which is, for example, a mixture of the cured product of the polymer monomer-containing composition and an inorganic filler (C). In the dental mill blank, the content of the component derived from the dental restorative curable composition is preferably 50 to 100% by mass, more preferably 60 to 100% by mass, even more preferably 70 to 100% by mass, even more preferably 80 to 100% by mass, and even more preferably 90 to 100% by mass, and may also be 100% by mass, based on 100% by mass of the total amount of the dental mill blank. The method for manufacturing the dental mill blank is not particularly limited. For example, there are a method of curing a curable composition for dental restoration by thermal polymerization (Method 1), or a method of bringing an inorganic filler molded body formed by press molding an inorganic filler into contact with a polymerizable monomer-containing composition and curing it by thermal polymerization (Method 2), etc.

[0141] As the Method 1, for example, it includes the following steps (iii) to (iv) in this order.

[0142] Step (iii): Filling step The filling step is a step of filling the curable composition for dental restoration into a polymerization container. For example, in the step (ii), it can also be filled into the polymerization container by extruding it while applying a load by a cylinder from within the defoamer container. The filling conditions are not particularly limited, but in order to fill efficiently, the extrusion load by the cylinder is preferably 1 to 100 kN, more preferably 3 to 80 kN, and even more preferably 5 to 50 kN. Also, during filling, heat treatment can be performed as necessary. The temperature during filling is not particularly limited, but in order to fill efficiently, 35 to 60 °C is preferred.

[0143] Step (iv): Polymerization step (polymerization step in Method 1) The polymerization step in Method 1 is a step of curing the paste-like curable dental restorative composition by a polymerization reaction. A container filled with the curable dental restorative composition is placed in a chamber capable of making the overall pressure predetermined, pressurized and heated, and polymerized so that the pressures inside and outside the container become equal. As this chamber, a pressure heating container such as an autoclave or a pressure cooker used in the industry can be used. The polymerization conditions are not particularly limited, but the pressure during polymerization is preferably 0.2 to 4.0 MPa, more preferably 0.3 to 2.0 MPa, and still more preferably 0.4 to 0.9 MPa. By being within this pressure range, cracks and bubbles can be further suppressed while suppressing the manufacturing cost. Further, the temperature during polymerization is preferably 60 to 180°C. Further, from the viewpoint of exhibiting higher flexural strength, the temperature during polymerization is preferably adjusted according to the 10-hour half-life temperature (τ) of the thermal polymerization initiator, more preferably τ - 20°C to τ + 30°C, and still more preferably τ - 15°C to τ + 25°C. Further, the holding time in the pressurized heating state during polymerization is preferably 10 to 120 minutes, more preferably 20 to 110 minutes, and still more preferably 30 to 90 minutes. By being within this time range, unreacted components are less likely to remain, and polymerization can be carried out with higher production efficiency.

[0144] As the Method 2, for example, it includes the following steps (v) to (vii) in this order.

[0145] Step (v): Pressing step The pressing process is a process for producing an inorganic filler molded body by press molding an inorganic filler. There are no particular restrictions on the method of press molding the inorganic filler, and known methods can be used. A specific method of press molding is to fill the inorganic filler into a press die of the desired size and apply pressure using an upper punch and a lower punch with a uniaxial press. The press pressure during uniaxial pressing can be set to an optimal value depending on the desired size of the inorganic filler molded body, the type and particle size of the inorganic filler, etc., and can be, for example, 10 MPa or more. A higher press pressure during uniaxial pressing is preferable because it makes it easier to obtain the desired dental mill blank and improves the stability of the inorganic filler molded body when it comes into contact with a polymerizable monomer-containing composition. On the other hand, considering factors such as the size of the inorganic filler molded body, productivity due to equipment factors, and the suppression of cracks and chips in the inorganic filler molded body due to friction with the die caused by excessive load, it is preferable that the press pressure during uniaxial pressing be, for example, 200 MPa or less. From the above-mentioned viewpoint, the press pressure during the uniaxial press is preferably 10 to 200 MPa, more preferably 20 to 180 MPa, and even more preferably 25 to 150 MPa. The press time during the uniaxial press can be set appropriately according to the press pressure, but is preferably 1 to 120 minutes.

[0146] In addition to uniaxial pressing, press molding may also be performed by cold isostatic pressing (CIP). In this case, CIP alone may be used, or both CIP and other pressing methods, such as the uniaxial pressing method described above, may be used. More specifically, press molding may be performed by CIP without performing the uniaxial pressing described above, or press molding may be performed by CIP after press molding with the uniaxial pressing method described above. With CIP press molding, it is usually possible to apply higher pressing pressure than with uniaxial pressing, and pressure can be applied uniformly to the inorganic filler molded body from three dimensions. Therefore, by performing press molding by CIP, undesirable minute voids inside the inorganic filler molded body and unevenness in the aggregation state of the inorganic filler can be eliminated. For the same reason, by performing press molding by CIP, the compressive density of the inorganic filler can be further improved, and a dental mill blank with a higher inorganic filler content can be obtained. Furthermore, when press molding is performed by CIP without using a uniaxial press, the inorganic filler can be filled into an elastic container such as silicone rubber or polyisoprene rubber, and then press-molded by CIP either as is or under reduced pressure (including a vacuum). Also, when press molding by CIP is performed after press molding by a uniaxial press, the molded body obtained by the uniaxial press can be pressed by CIP either as is or under reduced pressure (including a vacuum). It is preferable to use a higher pressure when press-molding by CIP. For example, a CIP device capable of pressurizing to about 1,000 MPa, manufactured by Kobe Steel, Ltd., can be used for press-molding by CIP. A higher pressure during CIP is preferable, regardless of whether a uniaxial press is used, because it makes it easier to obtain the desired dental mill blank and improves the stability of the inorganic filler molded body when it comes into contact with the polymerizable monomer-containing composition. From this viewpoint, the pressure during CIP is preferably 30 MPa or higher, more preferably 50 MPa or higher, and even more preferably 100 MPa or higher.Furthermore, considering factors such as productivity and the suppression of cracks and chipping in the inorganic filler molded body due to excessive load, the pressure during CIP is preferably 500 MPa or less, more preferably 450 MPa or less, and even more preferably 400 MPa or less. Also, as mentioned above, these lower and upper limits described in stages can be combined independently. For example, in one embodiment of the present invention, the pressure during CIP is preferably 30 to 500 MPa, more preferably 50 to 450 MPa, and even more preferably 100 to 400 MPa. The pressurizing time during CIP can be appropriately set according to the press pressure, but 1 to 120 minutes is preferred.

[0147] Process (vi): Impregnation process The impregnation step is a step in which the inorganic filler molded body obtained in step (v) is brought into contact with the polymerizable monomer-containing composition, and the polymerizable monomer-containing composition is infiltrated into the gaps of the inorganic filler molded body so that a dental restorative curable composition having a structure in which the inorganic filler is extremely densely dispersed in the polymerizable monomer-containing composition is obtained. From this viewpoint, in method 2, it is preferable to use an inorganic filler molded body that has not been sintered to form a porous body with interconnected bodies. There are no particular restrictions on the method of bringing the inorganic filler molded body into contact with the polymerizable monomer-containing composition, and a method that allows the polymerizable monomer-containing composition to penetrate into the gaps of the inorganic filler can be employed. For example, a method of immersing the inorganic filler molded body in the polymerizable monomer-containing composition is preferred because it is simpler. Through this immersion, the polymerizable monomer-containing composition can gradually penetrate into the inorganic filler molded body by capillary action. It is preferable that the surrounding environment at this time be under a reduced pressure atmosphere, as this promotes the penetration of the liquid polymerizable monomer-containing composition. Furthermore, it is preferable that the penetration of the polymerizable monomer-containing composition is further promoted by repeating the operation of returning to an atmospheric pressure atmosphere after being in a reduced pressure atmosphere (reduced pressure / atmospheric pressure operation) multiple times, thereby shortening the time required for the polymerizable monomer-containing composition to completely penetrate into the inorganic filler molded body. The degree of reduced pressure in the aforementioned reduced pressure atmosphere can be appropriately adjusted according to the viscosity of the polymerizable monomer-containing composition and the particle size of the inorganic filler, but for example, it is preferably 0.1 Pa to 10 kPa, more preferably 1 Pa to 5 kPa, and even more preferably 10 Pa to 2 kPa or less. Furthermore, the reduced pressure atmosphere is a vacuum (for example, 1 × 10⁻⁶). -8 ~1 × 10 -1 The pressure may be around Pa. Furthermore, since the polymerizable monomer-containing composition can be penetrated into the interior of the inorganic filler molded body more efficiently and the polymerizable monomer-containing composition can be penetrated into the interior of the inorganic filler molded body without any gaps, a method may be adopted in which the inorganic filler molded body, which appears to be impregnated with the polymerizable monomer-containing composition, obtained by immersing the inorganic filler molded body in the polymerizable monomer-containing composition as described above, is placed under pressurized conditions for a certain period of time. For example, a CIP device can be used as the pressurizing method. The pressurizing pressure is preferably 20 MPa or more, more preferably 50 MPa or more, and even more preferably 100 MPa or more. The operation of returning to atmospheric pressure after pressurizing (pressurizing / atmospheric pressure operation) may also be repeated multiple times. Furthermore, the temperature at which the inorganic filler molded body and the polymerizable monomer-containing composition are brought into contact is preferably 0°C or higher, more preferably 10°C or higher, even more preferably 20°C or higher, and may also be 30°C or higher, 40°C or higher, even more preferably 50°C or higher, and may also be 80°C or lower, more preferably 70°C or lower, and even more preferably 60°C or lower, in order to allow the polymerizable monomer-containing composition to penetrate into the interior of the inorganic filler molded body more efficiently. As mentioned above, these lower and upper limits described in stages can be combined independently. For example, in one embodiment of the present invention, the temperature at which the inorganic filler molded body and the polymerizable monomer-containing composition are brought into contact is preferably 0 to 80°C, more preferably 10 to 70°C, even more preferably 20 to 60°C, and may also be, for example, 30 to 80°C, 40 to 80°C, or 50 to 80°C. Furthermore, the contact time when bringing an inorganic filler molded body into contact with a polymerizable monomer-containing composition varies depending on the type of inorganic filler, the size of the inorganic filler molded body, the degree of penetration of the polymerizable monomer, and the contact method, and can be adjusted as appropriate. For example, when employing a method of immersing the inorganic filler molded body in a polymerizable monomer-containing composition, the contact time can be, for example, 0.1 to 240 hours. In particular, when immersion is performed under a reduced pressure atmosphere, the contact time can be, for example, 0.5 to 120 hours. On the other hand, when employing a method of applying pressure to the inorganic filler molded body to deliver the polymerizable monomer-containing composition to the inorganic filler molded body, the contact time can be, for example, 0.2 to 48 hours.

[0148] Step (vii): Polymerization step (polymerization step in Method 2) The polymerization step in Method 2 (Method 2) is a step in which an inorganic filler molded body is brought into contact with a polymerizable monomer-containing composition, and the polymerizable monomers contained in the polymerizable monomer-containing composition are polymerized and cured in a state in which the polymerizable monomer-containing composition has penetrated into the inorganic filler molded body (a state in which the polymerizable monomer-containing composition has impregnated). The polymerization temperature is preferably 60 to 180°C. Furthermore, from the viewpoint of exhibiting higher mechanical strength, the polymerization temperature is preferably set to the 10-hour half-life temperature (τ) of the thermal polymerization initiator, more preferably τ-20°C to τ+30°C, and even more preferably τ-15°C to τ+25°C. In addition, the holding time in the heated state during polymerization is preferably 10 to 120 minutes, more preferably 20 to 110 minutes, and even more preferably 30 to 90 minutes. This time range makes it less likely for unpolymerized material to remain and allows polymerization to be carried out with higher manufacturing efficiency.

[0149] <Uses of hardening compositions for dental restorations> One embodiment of the present invention, the curable composition for dental restorations, is suitable for use as a dental material because the cured product can achieve both high flexural strength and high fracture toughness, and also exhibits excellent polishability and opposing tooth wear characteristics. Specifically, it can be suitably used in the field of dental care as a dental material (particularly dental composite resin) that can replace a part or all of a natural tooth. Furthermore, one embodiment of the present invention, the curable composition for dental restorations, also exhibits excellent crack suppression during polymerization curing, resulting in a good appearance. Furthermore, due to its excellent properties as described above, the cured product obtained by polymerizing and curing the dental restorative curable composition, which is one aspect of the present invention, can be suitably used as a dental mill blank, which is a material to be cut in a CAD / CAM system manufactured by cutting with a milling device. [Examples]

[0150] The embodiments of this model will be described in more detail below with reference to examples and comparative examples, but the embodiments are not limited to the following examples.

[0151] The components used in the synthesis examples, manufacturing examples, examples, or comparative examples are described below, along with their abbreviations and names. Furthermore, the following characteristics of each component were measured using the following method.

[0152] <Number average molecular weight (Mn)> The number-average molecular weight (Mn) of component (A), PCIS-3 from synthesis example 5, and liquid polybutadiene-terminated diacrylate from synthesis example 6 was measured using gel permeation chromatography (GPC) by the following method. First, at room temperature (25±2℃), component (A) synthesized in Synthesis Examples 1-4, PCIS-3 synthesized in Synthesis Example 5, or liquid polybutadiene-terminated diacrylate used in Synthesis Example 6 were dissolved in tetrahydrofuran (containing 0.5 mg / mL of 3,5-di-t-butyl-4-hydroxytoluene (polymerization inhibitor)) to a concentration of 0.5 mg / mL for each component. The resulting solutions were then filtered through a solvent-resistant membrane filter with a pore diameter of 0.2 μm, "Myshoridisk®" (manufactured by Tosoh Corporation), to obtain sample solutions. The sample solutions were adjusted so that the concentration of the tetrahydrofuran-soluble components was 0.8% by mass. These sample solutions were then measured under the following conditions. Equipment: High-speed GPC system "HLC-8220GPC" (manufactured by Tosoh Corporation) Column: LF-604 double column (manufactured by Showa Denko Corporation) Eluent: Tetrahydrofuran Flow rate: 0.6mL / min Oven temperature: 40℃ Sample injection volume: 0.020 mL To calculate the molecular weight of the samples, standard polystyrene resins (e.g., "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) were used. Calibration curves were created by injecting 0.2 mL of a solution prepared by dissolving each sample in tetrahydrofuran (containing 0.5 mg / mL of 3,5-di-t-butyl-4-hydroxytoluene (polymerization inhibitor)) so that each sample had a molecular weight of 0.5 mg / mL. The calibration curves were approximated using a cubic equation obtained by the least squares method. The definition of number-average molecular weight (Mn) is described in "Fundamentals of Polymer Chemistry" (edited by the Society of Polymer Science, Japan, Tokyo Kagaku Dojin, 1978), and it can be calculated from molecular weight distribution curves obtained by GPC.

[0153] <Average primary particle diameter> The average primary particle size of component (C) is the D50 value based on volume, measured using a laser diffraction particle size distribution analyzer.

[0154] [Component (A): Terminal (meth)acryloyl-modified conjugated diene polymer (A)] [Synthesis Example 1] <Production of terminally (meth)acryloyl-modified conjugated diene polymer (a1-1)> In a 5L stainless steel autoclave under an air atmosphere, 160g of acrylate chloride, 200g of pyridine, and 1,500g of unhydrogenated polybutadiene "NISSO-PB(registered trademark) G-1000 (molecular weight distribution Mw / Mn 1.15, manufactured by Nippon Soda Co., Ltd.)" with both ends modified with hydroxyl groups were mixed and reacted at 60°C for 48 hours. After diluting the reaction solution with 1L of toluene, it was washed three times with 0.5L of distilled water, reprecipitation was performed in a 50 / 50 (volume ratio) distilled water / methanol solvent, and drying under reduced pressure was performed to obtain terminally acryloyl-modified unhydrogenated polybutadiene (a1-1). The obtained terminally acryloyl-modified unhydrogenated polybutadiene (a1-1) was subjected to IR measurement and yielded 1,735 cm⁻¹. -1(CO) carbonyl group absorption was confirmed. When the number average molecular weight (Mn) of the obtained terminal acryloyl-modified hydrogenated polybutadiene (a1-1) was measured by the GPC method, it was 1,500.

[0155] [Synthesis Example 2] [Production of terminal (meth)acryloyl-modified conjugated diene polymer (a2-1)] In a 5 L SUS autoclave, 390 g of isophorone diisocyanate, 3.5 g of aluminum alkyl acetoacetate diisopropylate (product name "Almicate M", manufactured by Kawaken Fine Chemical Co., Ltd.), and 200 g of 2-hydroxyethyl acrylate were mixed under an air atmosphere and reacted at 60 °C for 1 hour to synthesize Reactant A. Next, under an air atmosphere, 600 g of the previously synthesized Reactant A, 1,500 g of hydrogenated polybutadiene "NISSO-PB (registered trademark) GI-1000 (molecular weight distribution Mw / Mn 1.15, manufactured by Nippon Soda Co., Ltd.)" modified with hydroxyl groups at both ends, and 12.0 g of "Almicate M" were mixed and reacted at 60 °C for 2 hours. The reaction was terminated after confirming that the residual NCO was 0.1% or less. After diluting the reaction solution with 1 L of toluene, it was washed 3 times with 0.5 L of distilled water, reprecipitated with a solvent of 50 / 50 (volume ratio) of distilled water / methanol, and dried under reduced pressure to obtain terminal acryloyl-modified hydrogenated polybutadiene (a2-1). Regarding the obtained terminal acryloyl-modified hydrogenated polybutadiene (a2-1), 1 1H-NMR measurement was performed, and two NH signals (4.55 ppm, 4.70 ppm) were confirmed. Also, IR measurement was performed at 1,728 cm -1 (CO), 3,339 cm -1 (NH) urethane bond absorption was confirmed. When the number average molecular weight (Mn) of the obtained terminal acryloyl-modified hydrogenated polybutadiene (a2-1) was measured by the GPC method, it was 2,200. Note that "residual NCO (%)" indicates the mass of the isocyanate site (the product of the number of moles and 42.02 (NCO molecular weight)) in the mass of the compound, expressed as a percentage.

[0156] [Synthesis Example 3] <Preparation of terminally (meth)acryloyl-modified conjugated diene polymer (a2-2)> Except for replacing "NISSO-PB(registered trademark) GI-1000" with "NISSO-PB(registered trademark) GI-3000 (molecular weight distribution Mw / Mn 1.12, manufactured by Nippon Soda Co., Ltd.)", which has both ends modified with hydroxyl groups, the reaction and washing were carried out in the same manner as in Synthesis Example 2 to obtain terminally acryloyl-modified hydrogenated polybutadiene (a2-2). Regarding the obtained terminally acryloyl-modified hydrogenated polybutadiene (a2-2), 1 1H-NMR measurements were performed, and two NH signals (4.55 ppm and 4.70 ppm) were confirmed. In addition, IR measurements were performed, and the reading was 1,728 cm⁻¹. -1 (CO), 3,339cm -1 The absorption of the urethane bond in (NH) was confirmed. The number-average molecular weight (Mn) of the obtained terminally acryloyl-modified hydrogenated polybutadiene (a2-2) was measured by GPC and found to be 3,800.

[0157] [Synthesis Example 4] <Production of terminally (meth)acryloyl-modified conjugated diene polymers (a2-3)> The reaction and washing were carried out in the same manner as in Synthesis Example 2, except that "NISSO-PB(registered trademark) GI-1000" was replaced with "NISSO-PB(registered trademark) G-1000," an unhydrogenated polybutadiene modified with hydroxyl groups at both ends, and isophorone diisocyanate was replaced with tolylene diisocyanate, to obtain terminally acryloyl-modified unhydrogenated polybutadiene (a2-3). Regarding the obtained terminally acryloyl-modified added polybutadiene (a2-3), 1 1H-NMR measurements were performed, and two NH signals (4.55 ppm and 4.70 ppm) were confirmed. In addition, IR measurements were performed, and the reading was 1,728 cm⁻¹. -1 (CO), 3,339cm -1 The absorption of the urethane bond in (NH) was confirmed. The number-average molecular weight (Mn) of the obtained terminally acryloyl-modified hydrogenated polybutadiene (a2-3) was measured by GPC and found to be 2,100.

[0158] [Component (B): (meth)acrylic acid ester compound (B) having two or more (meth)acryloyloxy groups] UDMA: [2,2,4-trimethylhexamethylenebis(2-carbamoyloxyethyl)] dimethacrylate (manufactured by Kyoeisha Chemical Co., Ltd.) D2.6E: 2,2-Bis[4-methacryloyloxypolyethoxyphenyl]propane (average number of moles of ethoxy groups added: 2.6) (manufactured by Shin-Nakamura Chemical Industry Co., Ltd.) TEGDMA: Triethylene glycol dimethacrylate (manufactured by Shin-Nakamura Chemical Industry Co., Ltd.)

[0159] [Component (C): Inorganic filler (C)] UF2.0: Barium borosilicate glass (average primary particle size (D50) 2.0 μm, Schott GM27884UF2.0) UF1.5: Barium borosilicate glass (average primary particle size (D50) 1.5 μm, Schott GM27884UF1.5) NF180: Barium borosilicate glass (average primary particle size (D50) 0.180 μm, Schott GM27884NF180) Ox50: Fine particle silica (average primary particle size (D50) 0.040 μm, manufactured by Nippon Aerosil Co., Ltd. as "AEROSIL® OX50")

[0160] [Surface treatment agent] γ-MPS: γ-methacryloyloxypropyltrimethoxysilane (manufactured by Shin-Etsu Chemical Co., Ltd.)

[0161] [Component (D): Polymerization initiator (D)] <Photopolymerization initiator> CQ: Camphorquinone (manufactured by Tokyo Chemical Industry Co., Ltd.) TPP: 2,4,6-trimethylbenzoyldiphenylphosphine oxide (manufactured by Tokyo Chemical Industry Co., Ltd.) <Thermal polymerization initiator> THP: 1,1,3,3-tetramethylbutylhydroperoxide (manufactured by NOF Corporation) BPO: Benzoyl peroxide (manufactured by NOF Corporation)

[0162] [Polymerization accelerator] JJA: 4-(N,N-dimethylamino)ethyl benzoate

[0163] [Polymerization inhibitor] BHT: 3,5-di-t-butyl-4-hydroxytoluene

[0164] [Other polymerizable monomers] DEAA: N,N-Diethylacrylamide (manufactured by KJ Chemicals Co., Ltd.) MMA: Methyl methacrylate

[0165] [Other polymerizable monomers (terminal (meth)acryloyl-modified polycarbonate compounds)] [Synthesis Example 5] <Manufacturing of terminally (meth)acryloyl-modified polycarbonate (PCIS-3)> 80 g of BENEBiOL® HS0840H (manufactured by Mitsubishi Chemical Corporation), a polycarbonate diol containing terminal hydroxyl groups and having 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 hydrochloric acid aqueous solution, and saturated sodium carbonate aqueous solution in that order, and dried over magnesium sulfate. After concentrating the dried solution, it was poured into methanol, the precipitate was recovered by filtration, and vacuum drying was performed to obtain a methacrylic acid ester compound having a polycarbonate structure in which the hydroxyl residues at both ends derived from the repeating units constituting the polymer structure are directly methacryloylated (number average molecular weight (Mn) 900, hereinafter abbreviated as "PCIS-3").

[0166] [Polymer particles (other fillers)] [Synthesis Example 6] <Production of polymethyl (meth)acrylate particles (PMP) containing conjugated diene compounds> 90 parts by weight of methyl methacrylate were dissolved in 10 parts by weight of liquid polybutadiene-terminated diacrylate (trade name "BAC-45", manufactured by Osaka Organic Chemical Industry Co., Ltd.) with a number-average molecular weight (Mn) of 2,900. Suspension polymerization was carried out using 0.5 parts by weight of BPO to obtain polymethyl methacrylate particles (PMP).

[0167] The polymerizable monomer compositions used in the examples and comparative examples were prepared by the following method. The compositions of the prepared polymerizable monomer-containing compositions are shown in Tables 1 and 2 below. [Manufacturing Example 1] A polymerizable monomer-containing composition (EM1) was prepared by dissolving 85 parts by mass of UDMA and 15 parts by mass of a1-1 with 0.2 parts by mass of CQ as a photopolymerization initiator, 0.25 parts by mass of TPP, and 0.3 parts by mass of JJA as a polymerization accelerator under yellow light at 40°C.

[0168] [Manufacturing Examples 2-7] Each component was blended to the amounts shown in Table 1 below, and polymerizable monomer-containing compositions (EM2) to (EM7) were prepared in the same manner as in Production Example 1.

[0169] [Manufacturing Example 8] A polymerizable monomer-containing composition (EM8) was prepared by dissolving 0.5 parts by mass of THP as a thermal polymerization initiator in 85 parts by mass of UDMA and 15 parts by mass of a1-1 under yellow light at 40°C.

[0170] [Manufacturing Example 9] A polymerizable monomer-containing composition (EM9) was prepared by dissolving 0.5 parts by mass of THP as a thermal polymerization initiator in 85 parts by mass of UDMA and 15 parts by mass of a2-3 under yellow light at 40°C.

[0171] [Manufacturing Example 10] A polymerizable monomer-containing composition (CM1) was prepared by dissolving 3 parts by mass of UDMA, 60 parts by mass of a2-1, and 37 parts by mass of DEAA with 2.0 parts by mass of the photopolymerization initiator TPP and 0.05 parts by mass of BHT as a polymerization inhibitor under yellow light at 40°C.

[0172] [Manufacturing Example 11] A polymerizable monomer-containing composition (CM2) was prepared by dissolving 80 parts by mass of UDMA and 20 parts by mass of PCIS-3 with 0.2 parts by mass of CQ as a photopolymerization initiator, 0.25 parts by mass of TPP, and 0.3 parts by mass of JJA as a polymerization accelerator under yellow light at 40°C.

[0173] [Manufacturing Example 12] A polymerizable monomer-containing composition (CM3) was prepared by dissolving 0.3 parts by weight of BPO as a thermal polymerization initiator in 90 parts by mass of MMA and 10 parts by mass of TEGGMA under yellow light at 40°C.

[0174] [Manufacturing Example 13] A polymerizable monomer-containing composition (CM4) was prepared by dissolving 0.5 parts by mass of THP as a thermal polymerization initiator in 80 parts by mass of UDMA and 20 parts by mass of PCIS-3 under yellow light at 40°C.

[0175] [Manufacturing Example 14] A polymerizable monomer-containing composition (CM5) 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 under yellow light at 40°C.

[0176] [Table 1]

[0177] [Table 2]

[0178] The inorganic fillers used in the examples and comparative examples were manufactured by the following method. [Manufacturing example C1] 100 parts by mass of NF180 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 the mixture was stirred at room temperature (25°C) for 2 hours. The solvent was removed by distillation under reduced pressure, and the mixture was further dried at 90°C for 3 hours to obtain an inorganic filler (SC1) having an inorganic filler surface-treated with a surface treatment agent.

[0179] [Manufacturing example C2] A mixture of 80 parts by mass of UF2.0 and 20 parts by mass of NF180 was dispersed in 300 parts by mass of ethanol. 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 the mixture was stirred at room temperature (25°C) for 2 hours. The solvent was removed by distillation under reduced pressure, and the mixture was further surface-treated by drying at 90°C for 3 hours to obtain an inorganic filler (SC2) having an inorganic filler surface-treated with a surface treatment agent.

[0180] [Manufacturing example C3] A mixture of 100 parts by mass of UF1.5 and 20 parts by mass of Ox50 was dispersed in 300 parts by mass of toluene, and 4 parts by mass of γ-MPS was added and heated under reflux for 2 hours. The solvent was removed by distillation under reduced pressure, and the surface was further treated by drying at 90°C for 3 hours to obtain an inorganic filler (SC3) having an inorganic filler surface-treated with a surface treatment agent.

[0181] The compositions of inorganic fillers (SC1 to SC3) having an inorganic filler surface-treated with a surface treatment agent are shown in Table 3 below.

[0182] [Table 3]

[0183] The physical properties of the curable dental restorative compositions and the cured products obtained using said curable dental restorative compositions in the examples and comparative examples were evaluated by the following property evaluation tests.

[0184] (Test 1-1) Bending strength, fracture toughness (3-point bending test, dental composite resin) Regarding dental composite resins, after vacuum degassing the dental restorative curable compositions of each manufactured example and comparative example, they were filled into a stainless steel mold (dimensions: 2mm thick x 2mm wide x 25mm long) and the upper and lower surfaces in the thickness direction (area 50mm) were filled. 2 The material was pressed onto a glass slide and cured using a dental visible light curing unit ("PenCure® 2000", manufactured by Morita Corporation) by irradiating each point for 10 seconds, 5 points on each side, and curing both sides. Five cured samples were prepared for each example and comparative example. The cured samples were removed from the mold, and the flexural strength and fracture toughness of the cured samples were measured using a universal testing machine (manufactured by Shimadzu Corporation, product code "AG-I 100kN") under conditions of a support distance of 20 mm and a crosshead speed of 1 mm / min. The average of the measured values ​​of the five samples was calculated and defined as the flexural strength and fracture toughness of the dental composite resin (N=5). However, for the dental composite resin of Comparative Example 4, a test piece (dimensions: 2 mm thick x 2 mm wide x 25 mm long) was prepared from the cured material obtained in Comparative Example 4 using a diamond cutter, and a sample was prepared by dry polishing it with #1000 abrasive paper, #2000 abrasive paper, and #3000 abrasive paper in that order. The same method as described above was used to perform the test on this sample. For dental composite resins, a flexural strength of 140 MPa or higher was considered good, and 180 MPa or higher was considered even better. Furthermore, for dental composite resins, a fracture toughness of 15 mJ or higher was considered good, and 20 mJ or higher was considered even better.

[0185] (Test 1-2) Bending strength, fracture toughness (3-point bending test, dental mill blank) Regarding the dental mill blanks, test specimens (dimensions: 1.2 mm thick x 4 mm wide x 14 mm long) were prepared from the dental mill blanks of each manufactured example and comparative example using a diamond cutter, polished with #2000 abrasive paper to prepare samples, the support distance when using the universal testing machine was set to 12 mm, and 10 hardened samples were prepared for each type of specimen. Except for these differences, the measurements were performed in the same manner as for the dental composite resin samples, and the average of the measured values ​​of the 10 samples was calculated to determine the bending strength and fracture toughness of the dental mill blanks (N=10). For dental mill blanks, a bending strength of 240 MPa or higher was considered good, and 280 MPa or higher was considered even better. Furthermore, for dental mill blanks, a fracture toughness of 30 mJ or higher was considered good, and 35 mJ or higher was considered even better.

[0186] (Test 2-1) Water resistance (3-point bending test, dental composite resin) For dental composite resins, samples of cured dental restorative compositions from each example and comparative example, manufactured in the same manner as in Test 1-1, were immersed in water at 37°C for 30 days. Then, the flexural strength was measured in the same manner as in Test 1-1, and the average of the measured values ​​from five samples was calculated to determine the flexural strength of the dental composite resin after immersion in water (N=5). The rate of change in bending strength after immersion in water (also called the "bending strength reduction rate") relative to the initial bending strength measured in Test 1-1 was calculated using the following formula. A bending strength reduction rate of 10% or less was judged to indicate excellent water resistance, and 5% or less was judged to indicate even better water resistance. Bending strength reduction rate (%) = [{Initial bending strength (MPa) - Bending strength after immersion in water (MPa)} / Initial bending strength (MPa)] × 100

[0187] (Test 2-2) Water resistance (3-point bending test, dental mill blank) For dental mill blanks, samples of cured dental restorative hardening compositions for each example and comparative example, manufactured in the same manner as in Test 1-2, were immersed in water at 37°C for 30 days. Then, the flexural strength was measured in the same manner as in Test 1, and the average value of the measurements from 10 samples was calculated to determine the flexural strength of the dental mill blanks after immersion in water (N=10). The rate of change in bending strength after immersion in water (also called the "bending strength reduction rate") relative to the initial bending strength measured in Test 1-2 above was calculated using the following formula. A bending strength reduction rate of 10% or less was judged to indicate excellent water resistance, and a rate of 5% or less was judged to indicate even better water resistance. Bending strength reduction rate (%) = [{Initial bending strength (MPa) - Bending strength after immersion in water (MPa)} / Initial bending strength (MPa)] × 100

[0188] (Test 3-1) Ease of polishing (polishing test, dental composite resin) For dental composite resins, the curable dental restorative compositions of each example and comparative example were vacuum degassed and then filled into polytetrafluoroethylene molds (circular: inner diameter 10 mm, thickness 2.0 mm). The upper and lower surfaces (open surfaces) in the thickness direction of the mold were pressed against a glass slide, and the resin was cured by irradiating it with a dental visible light curing unit (PenCure® 2000, manufactured by Morita Corporation) from the top side for 10 seconds to obtain test specimens. The test specimens were removed from the molds, and the smooth surface that had been pressed against the glass slide was polished with #600 abrasive paper under dry conditions. Furthermore, using a dental laboratory engine "Volvere® RX" (manufactured by Nakanishi Corporation), the specimens were polished under water conditions using a brown silicone point (manufactured by Matsukaze Corporation) at a rotation speed of 5,000 rpm for 10 seconds, followed by polishing with a blue silicone point (manufactured by Matsukaze Corporation) at a rotation speed of 5,000 rpm for 10 seconds. For the polished test specimens, the glossiness was measured at four locations on the specimen using a gloss meter ("VG-2000", manufactured by Nippon Denshoku Industries Co., Ltd.), and the average of each measurement was calculated (N=4). The glossiness measured was 60° specular gloss (Gs(60°)). However, for the dental composite resin of Comparative Example 4, a test piece (dimensions: 10 mm long x 10 mm wide x 2.0 mm thick) was prepared from the cured material obtained in Comparative Example 4 using a diamond cutter, and its surface (square face) was polished with #600 abrasive paper under dry conditions. Furthermore, using the dental laboratory engine "Volvere® RX" (manufactured by Nakanishi Corporation), the test piece was polished for 10 seconds at a rotation speed of 5,000 rpm using a brown silicone point (manufactured by Matsukaze Corporation) under water-filled conditions, and then polished for 10 seconds at a rotation speed of 5,000 rpm using a blue silicone point (manufactured by Matsukaze Corporation). The test piece after polishing was tested using the same method as described above. The gloss level of the dental composite resin is preferably 70% or higher, more preferably 80% or higher, and even more preferably 90% or higher.

[0189] (Test 3-2) Ease of polishing (polishing test, dental mill blank) For the dental mill blanks, samples with a smooth surface for evaluating polishability, resembling anterior teeth, were milled from the dental mill blanks of each manufactured example and comparative example using a dental milling device "DWX-52D" (manufactured by Roland Corporation). The anterior tooth-shaped samples were designed so that the smooth surface was located in the area corresponding to the buccal region of the anterior teeth. Next, using a dental laboratory engine "Volvere® RX" (manufactured by Nakanishi Corporation), the milling scratches were removed using a silicone point (EVE Universal White H4, manufactured by EVE Ernst Vetter GmbH). Subsequently, the smooth surface after scratch removal was polished for 60 seconds at a rotation speed of 5,000 rpm using a Robinson brush with "Porcelain Haydn" (manufactured by Tokyo Dental Materials Co., Ltd.) as the polishing agent. For the polished samples, the glossiness of four locations on the smooth surface was measured using a gloss meter ("VG-2000", manufactured by Nippon Denshoku Industries Ltd.), and the average value of each measurement was calculated (N=4). The gloss level was measured using 60° specular gloss (Gs(60°)). The gloss level of the dental mill blank is preferably 60% or higher, more preferably 70% or higher, and even more preferably 80% or higher.

[0190] (Test 4-1) Abrasion characteristics of opposing teeth (Reinfelder test, dental composite resin) First, the enamel surface of the bovine tooth was prepared. The enamel portion of the bovine tooth surface was polished wet with #80 grit sandpaper followed by #1000 grit sandpaper to create a flat surface. Next, the test specimen was embedded in a metal mold using a self-curing resin (manufactured by GC Corporation, product name "Unifast® II") to expose the smoothed enamel surface. For dental composite resins, the curable dental restorative compositions of each example and comparative example were vacuum degassed and then filled into hemispherical polytetrafluoroethylene molds (φ11 mm). The filled dental curable compositions were placed upright on a cylindrical plastic bar and irradiated with light for 3 minutes using an LED polymerization unit (Morita Corporation, product name "α Light V"). After light irradiation, the surface of the resulting hemispherical cured material was polished dry with #1000, #2000, and #3000 grit sandpaper in that order until glossy to obtain hemispherical samples. The obtained hemispherical samples and the aforementioned embedded bovine tooth enamel were set in a Reinfelder testing machine (Navic Corporation). At room temperature in water, the hemispherical samples were subjected to a curing rate of 7.9 kg / cm³ against the completely fixed bovine tooth enamel. 2 Under a load, the samples were brought into contact while rotating 30°, and the load was released after 1 second while rotating -30°. This cycle was repeated 400,000 times. Repeated stress was applied by intermittently bringing the two samples into contact. Subsequently, the amount of wear on the bovine tooth enamel was measured using a surface roughness meter ("LASER FOCUS DISPLACEMENT MATER LT-8100," manufactured by Keyence Corporation). Bovine tooth enamel and hemispherical samples were prepared in the same manner, and the same test was repeated. The average of the measured values ​​from two tests was calculated (N=2). However, with respect to the dental composite resin of Comparative Example 4, a hemispherical sample with a diameter of φ11 mm was milled from the hardened material obtained in Comparative Example 4 using a dental milling device "DWX-52D" (manufactured by Roland Corporation). The surface of the hemispherical sample was then polished dry with #1000, #2000, and #3000 grit sandpaper in that order until it became glossy. The same method as described above was used to test the polished hemispherical sample. The wear rate for dental composite resin is 0.30 mm. 3 Preferably, the following: 0.25 mm 3 The following is more preferable: 0.20 mm 3 The following is even more preferable:

[0191] (Test 4-2) Abrasion characteristics of opposing teeth (Reinfelder test, dental mill blank) First, the enamel surface of the bovine tooth was prepared. The enamel portion of the bovine tooth surface was polished wet with #80 grit sandpaper followed by #1000 grit sandpaper to create a flat surface. Next, the test specimen was embedded in a metal mold using a self-curing resin (manufactured by GC Corporation, product name "Unifast® II") to expose the smoothed enamel surface. For the dental mill blanks, hemispherical samples with a diameter of φ10.0 mm were milled from each of the manufactured dental mill blanks for the examples and comparative examples using a dental milling device "DWX-52D" (manufactured by Roland Corporation). Next, using a dental laboratory engine "Volvere® RX" (manufactured by Nakanishi Corporation), the cutting marks were removed with a silicon point (EVE Universal White H4, manufactured by EVE Ernst Vetter GmbH). Then, using "Porseny Haydn" (manufactured by Tokyo Dental Materials Co., Ltd.) as an abrasive, the surface was polished with a Robinson brush at a rotation speed of 5,000 rpm for 60 seconds, and then polished with a felt buff at a rotation speed of 5,000 rpm until the surface was glossy to obtain hemispherical samples. The obtained hemispherical samples and the aforementioned embedded bovine tooth enamel were set in a Reinfelder testing machine (manufactured by Navic Corporation). At room temperature in water, the hemispherical samples were subjected to a 15.6 kg / cm³ treatment on the completely fixed bovine tooth enamel. 2Under a load, the samples were brought into contact while rotating 35°, and the load was released after 1 second while rotating -35°. This cycle was repeated 100,000 times. Repeated stress was applied by intermittently bringing the two samples into contact. Subsequently, the amount of wear on the bovine tooth enamel was measured using a surface roughness meter ("LASER FOCUS DISPLACEMENT MATER LT-8100," manufactured by Keyence Corporation). Bovine tooth enamel and hemispherical samples were prepared in the same manner, and the same test was repeated. The average of the measured values ​​from two tests was calculated (N=2). The wear amount for dental mill blanks is 0.10 mm. 3 Preferably, the following: 0.07 mm 3 The following is more preferable: 0.05 mm 3 The following is even more preferable:

[0192] (Test 5-1) Crack occurrence rate of hardened material (X-ray CT imaging, dental composite resin) For dental composite resins, the curable dental restorative compositions of each example and comparative example were vacuum degassed and then filled into polytetrafluoroethylene molds (circular: inner diameter 10 mm, thickness 2.0 mm). The upper and lower surfaces (open surfaces) in the thickness direction of the mold were pressed against a glass slide, and the material was cured by irradiating it with a dental visible light curing unit (PenCure® 2000, manufactured by Morita Corporation) from the top side for 10 seconds. The cured material was removed from the mold, and the presence or absence of cracks in the interior and exterior of 10 cured materials for each example was evaluated using a desktop microfocus X-ray CT system (Shimadzu Corporation, "inspeXio® SMX-90CT") (N=10). However, with respect to the dental composite resin of Comparative Example 4, the presence or absence of internal and external cracks in 10 cured products obtained by the method described in the section for Comparative Example 4 was evaluated using the aforementioned desktop microfocus X-ray CT system (N=10). In evaluating the crack occurrence rate of the cured product, it is preferable that the number of cracked cured products be one or less, and most preferably zero. On the other hand, if there are three or more cracks, the product is judged to be of poor quality from the standpoint of reduced mechanical strength and poor appearance.

[0193] (Test 5-2) Crack occurrence rate of hardened material (X-ray CT imaging, dental mill blank) For each example and comparative example of the manufactured curable dental restorative composition, the presence or absence of internal and external cracks in 10 cured samples was evaluated using a desktop microfocus X-ray CT system (Shimadzu Corporation, "inspeXio® SMX-90CT") (N=10). As an evaluation of the crack occurrence rate of the cured samples, it is preferable that the number of cracked samples be one or less, and most preferably zero. On the other hand, if there are three or more cracks, the quality is judged to be poor from the standpoint of reduced mechanical strength and poor appearance.

[0194] The curable dental restorative compositions and cured products of the curable dental restorative compositions according to the examples and comparative examples were manufactured by the following method.

[0195] [Examples 1-8, Comparative Examples 1-3] (Dental Composite Resin) Using the polymerizable monomer-containing compositions (EM1-7, CM1, 2) and inorganic fillers (SC1-2) obtained in the above production examples, the materials were mixed and kneaded at 40°C under yellow light in the composition ratios shown in Table 4 or 5 below, and the resulting mixtures were degassed under vacuum to prepare paste-like curable dental restorative compositions of Examples 1-8 and Comparative Examples 1-3. The above-mentioned property evaluation tests were performed on the prepared curable dental restorative compositions. The results are shown in Tables 4 and 5 below.

[0196] [Comparative Example 4] (Dental composite resin containing PMP) As a powder component, 10 g of polymethyl methacrylate particles (PMP) obtained in Synthesis Example 5 and 4.5 g of polymerizable monomer-containing composition (CM3) obtained in the Production Example were mixed and kneaded together under yellow light at 40°C until homogenized, and then vacuum degassed to prepare the paste-like curable dental restorative composition of Comparative Example 4. Next, the curable dental restorative composition was filled into a plaster mold measuring 65 mm (length) x 40 mm (width) x 15 mm (depth), and the temperature was raised from room temperature to 70°C in 30 minutes, after which it was maintained at 70°C for 30 minutes for prepolymerization. Subsequently, the temperature was raised from 70°C to 100°C over 10 minutes, and then maintained at 100°C for 40 minutes for main polymerization to obtain a cured PMP-containing dental composite resin. The results are shown in Table 5 below.

[0197] [Table 4]

[0198] [Table 5]

[0199] As shown in Table 4, the cured products of the dental restorative curable compositions obtained in Examples 1 to 8 were found to have high flexural strength and fracture toughness, and showed little decrease in strength when immersed in 37°C water, simulating an oral cavity environment, and had excellent water resistance. Furthermore, the cured products were found to be highly polishable, easily producing a glossy finish during polishing, and were less likely to wear down bovine tooth enamel due to occlusion, exhibiting excellent opposing tooth abrasion characteristics. In addition, all of the obtained cured products were free of cracks. On the other hand, as shown in Table 5, compared to the examples, the cured products of the dental restorative curable compositions obtained in Comparative Examples 1 and 2 had significantly lower flexural strength due to the absence of inorganic fillers, and were difficult to polish, resulting in poor polishability. Similarly, the cured product of the dental restorative curable composition obtained in Comparative Example 3 was also difficult to polish, resulting in poor polishability. Furthermore, the cured product of the dental restorative curable composition obtained in Comparative Example 4 was significantly inferior to the examples in all aspects, including flexural strength, fracture toughness, polishability, and opposing tooth wear characteristics.

[0200] [Examples 9-11, Comparative Example 5] (Dental Mill Blanks) Using the polymerizable monomer-containing compositions (EM8, EM9, CM4) and inorganic fillers (SC1-2) obtained in the above manufacturing example, the materials were mixed and kneaded at 40°C under yellow light in the composition ratios shown in Table 6 below, and the resulting mixtures were degassed under vacuum to prepare the paste-like curable dental restorative compositions of Examples 9-11 and Comparative Example 5. Next, the curable dental restorative compositions were poured into a rectangular resin container measuring 15 mm (length) x 15 mm (width) x 20 mm (depth), fixed in the chamber of an autoclave (manufactured by Kyoshin Engineering Co., Ltd.), and after 12 purgings with 99.99% nitrogen at 0.15 MPa, the pressure was increased to 0.5 MPa with nitrogen of the same purity. Simultaneously with the completion of the pressure increase, the temperature inside the chamber was raised to 130°C and held for 60 minutes to polymerize and cure. Finally, the cured product was removed from the container to obtain a dental mill blank. The obtained cured product was subjected to the above-mentioned property evaluation test. The results are shown in Table 6 below.

[0201] [Comparative Example 6] (Dental Mill Blank) (1) 200 g of the inorganic filler (SC3) obtained in the above manufacturing example was placed on the lower punch bar of a press die having a circular hole of φ200 mm. The powder was leveled by tapping, the upper punch bar was set on top, and a table press was used to perform uniaxial pressing (press pressure: 300 kN (26.5 MPa), pressing time: 5 minutes). The upper and lower punch bars were removed from the die and the molded body in which the inorganic filler (SC3) had aggregated was removed. The molded body obtained by the uniaxial press was further pressed by CIP (pressure: 350 MPa, pressing time: 20 minutes) to obtain an inorganic filler molded body. (2) The obtained inorganic filler (SC3) molded body was immersed in a polymerizable monomer-containing composition (CM5), degassed under reduced pressure (10 hPa), and allowed to stand at 70°C for 48 hours to obtain an inorganic filler molded body impregnated with the polymerizable monomer-containing composition (polymerizable monomer-impregnated molded body). This polymerizable monomer-impregnated molded body was removed, placed on a glass slide, and photopolymerized by irradiating with UV light from a UV light generator (Toshiba Corporation, black light fluorescent lamp) for 60 minutes. After that, it was heated in a hot air dryer at 70°C for 24 hours, and then heated at 110°C for 5 hours to obtain a cured product as a dental mill blank. The obtained cured product was subjected to the above-mentioned property evaluation test. The results are shown in Table 6 below.

[0202] [Table 6]

[0203] The cured materials obtained in Examples 9-11 exhibited high flexural strength and fracture toughness, showed minimal strength reduction after immersion in 37°C water (simulating oral cavity conditions), and demonstrated excellent water resistance. Furthermore, the cured materials were found to be highly polishable, easily producing a glossy finish during polishing, and exhibited excellent abrasion characteristics against opposing teeth, as they were less likely to wear down bovine tooth enamel during occlusion. In addition, all obtained cured materials were free of cracks. On the other hand, the cured product obtained in Comparative Example 5 was found to have poor polishability, with low gloss even after polishing, and was prone to cracking during curing. Furthermore, the cured product obtained in Comparative Example 6 was found to have inferior water resistance, polishability, and opposing tooth wear characteristics compared to the examples, and was also prone to cracking during curing.

[0204] From the above results, it was found that the curable composition for dental restoration, which is one aspect of the present invention, is a composition that can produce a cured product having flexural strength, fracture toughness, and water resistance, as well as excellent polishability and opposing tooth wear characteristics. It was also found to have excellent opposing tooth wear characteristics. Furthermore, it was confirmed that there was no crack formation during curing and the appearance of the resulting cured product was good. [Industrial applicability]

[0205] The cured product obtained from the dental restorative curable composition according to one aspect of the present invention exhibits excellent flexural strength, fracture toughness, and opposing tooth wear characteristics. That is, it has sufficient mechanical strength to replace natural teeth and does not cause wear on opposing teeth, making it suitable for use as a material for restoring tooth defects and caries, particularly as a dental composite resin. Furthermore, the cured product is suitable for use as a dental mill blank. Moreover, the cured product obtained from the dental restorative curable composition according to one aspect of the present invention is crack-free and has a good appearance. In addition, the dental restorative curable composition according to one aspect of the present invention is also excellent in terms of ease of handling due to its excellent polishability.

Claims

1. The material contains a terminal (meth)acryloyl-modified conjugated diene polymer (A), a (meth)acrylic acid ester compound (B) having two or more (meth)acryloyloxy groups (excluding the terminal (meth)acryloyl-modified conjugated diene polymer (A)), an inorganic filler (C), and a polymerization initiator (D). A curable dental restorative composition in which the terminal (meth)acryloyl-modified conjugated diene polymer (A) is at least one selected from the group consisting of terminal (meth)acryloyl-modified conjugated diene polymer (a1) represented by the following general formula (I) and terminal (meth)acryloyl-modified conjugated diene polymer (a2) represented by the following general formula (II). 【Chemistry 1】 (In general formula (I), R １ R is a hydrogen atom or a methyl group, ２ is a single bond or an ethylene group, a is 1 or 2, A １ A is a polymer of a conjugated diene compound or a hydrogenated product thereof, １ At least one of the ends of the molecular structure is R ２ They combine. If a is 2, then there are two R １ These R elements may be identical to each other, or they may be different, and there are two R elements. ２ They may be the same as each other, or they may be different. 【Chemistry 2】 (In general formula (II), R ３ is a hydrogen atom or a methyl group, R ４ and R ５ are each independently a divalent group derived from an organic compound, R ６ is a single bond or an ethylene group, b is 1 or 2, A ２ is a polymer of a conjugated diene compound or a hydrogenated product thereof, and R ２ is bonded to at least one of the terminals of the molecular structure of A ６ . If b is 2, then there are two R ３ There may be two Rs that are identical to each other, or they may be different to each other. ４ There may be two Rs that are identical to each other, or they may be different to each other. ５ These R elements may be identical to each other, or they may be different, and there are two R elements. ６ They may be the same as each other, or they may be different.

2. The dental restorative curable composition according to claim 1, wherein the content of component (C) is 50 to 95% by mass of the total amount of the dental restorative curable composition.

3. R ４ and R ５ The curable dental restorative composition according to claim 1, wherein each of the divalent groups derived from the organic compound represented by is independently a group consisting of an unsubstituted or substituted C1-C20 aliphatic hydrocarbon group, an unsubstituted or substituted C1-C20 aliphatic hydrocarbon group having an ether bond, an unsubstituted or substituted ring-forming C3-C20 alicyclic hydrocarbon group, an unsubstituted or substituted ring-forming C6-C20 aromatic hydrocarbon group, an unsubstituted or substituted ring-forming C3-C20 heterocyclic group, or a group in which at least two types selected from the group consisting of an unsubstituted or substituted C1-C20 aliphatic hydrocarbon group, an unsubstituted or substituted C1-C20 aliphatic hydrocarbon group having an ether bond, an unsubstituted or substituted ring-forming C3-C20 alicyclic hydrocarbon group, an unsubstituted or substituted ring-forming C6-C20 aromatic hydrocarbon group, and an unsubstituted or substituted ring-forming C3-C20 heterocyclic group are bonded together in groups of 2 to 6.

4. R ４ The dental restorative curable composition according to claim 1, wherein the group is a divalent group obtained by removing two hydrogen atoms from one selected from the group consisting of ethane, n-propane, isopropane, n-butane, isobutane, sec-butane, n-hexane, benzene, adamantane, diethyl ether, 1,2-diethoxyethane, and diethylene glycol diethyl ether.

5. R ５ The dental restorative curable composition according to claim 1, wherein the group is a divalent group obtained by removing two hydrogen atoms from one selected from the group consisting of 3,3,5,5-tetramethylcyclohexane, toluene, 4,4'-diphenylmethane, naphthalene, xylene, benzene, 3,3'-dichloro-4,4'-diphenylmethane, n-hexane, 4,4'-dicyclohexylmethane, hydrogenated xylene, triphenylmethane, and hexamethylbenzene.

6. A １ and A ２ The dental restorative curable composition according to claim 1, wherein each is independently polybutadiene, polyisoprene, a copolymer of butadiene and isoprene, a hydrogenated polybutadiene, a hydrogenated polyisoprene, or a hydrogenated copolymer of butadiene and isoprene.

7. The dental restorative curable composition according to claim 1, wherein the number average molecular weight of component (A) is 500 to 100,000.

8. R １ and R ３ The dental restorative curable composition according to claim 1, wherein each is independently a hydrogen atom.

9. The dental restorative curable composition according to claim 1, wherein the content of component (A) is 3 to 33% by mass of the total 100% by mass of polymerizable monomers.

10. The dental restorative curable composition according to claim 1, wherein the content of component (B) is 67 to 97% by mass of the total 100% by mass of polymerizable monomers.

11. The content of the polymerizable monomer-containing composition, which is a composition obtained by removing component (C) from the dental restorative curable composition, is 5 to 50% by mass of the total amount of the dental restorative curable composition (100% by mass), and The curable dental restorative composition according to claim 1, wherein the total content of polymerizable monomers containing at least component (A) and component (B) is 70 to 99.999% by mass of the total amount of the polymerizable monomer-containing composition.

12. The dental restorative curable composition according to claim 1, wherein the average primary particle size (D50) of component (C) is 0.001 to 5 μm.

13. The curable dental restorative composition according to claim 1, wherein the polymerization initiator (D) comprises a photopolymerization initiator.

14. The curable dental restorative composition according to claim 1, wherein the polymerization initiator (D) includes a thermal polymerization initiator.

15. A dental restorative curable composition according to any one of claims 1 to 14, for use with dental composite resin.

16. A dental restorative curable composition according to any one of claims 1 to 14, for use in dental mill blanks.

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