Curable composition for dental restoration

Abstract

To provide a curable composition for dental restoration that yields a cured product having high flexural strength and fracture toughness and also having a high gloss retention rate.SOLUTION: A curable composition for dental restoration comprises (A) a (meth)acrylic acid ester compound having two or more (meth)acryloyloxy groups in one molecule, (B) an aromatic vinyl compound, (C) an inorganic filler, and (D) a polymerization initiator. The aromatic vinyl compound (B) is represented by the following formula (I). (In formula (I), X is specifically defined in the specification).SELECTED DRAWING: None

Description

Technical Field

[0001] The present invention relates to a curable composition for dental restoration.

Background Art

[0002] A curable composition for dental restoration composed of a polymerizable monomer, a filler, and a polymerization initiator is called dental composite resin and is currently the most widely used dental material for repairing tooth defects and caries. On the other hand, dental mill blanks are materials used for the production of dental prostheses such as inlays and crowns by a CAD / CAM system designed by a computer and machined by a milling device, and the demand has been increasing rapidly in recent years. As dental mill blanks, block bodies in the shape of a rectangular parallelepiped, cylinder, disk, etc. having an appropriate size are supplied, and a restorative of a crown shape or a dental arch shape is obtained by setting this in a cutting machine and cutting it out. As materials for dental mill blanks, various materials have been proposed, such as glass ceramics, zirconia, titanium, acrylic resin, and composite materials containing a polymer resin and an inorganic filler. For example, Patent Document 1 discloses a curable composition for dental restoration containing a (meth)acrylic acid ester compound having two or more (meth)acryloyloxy groups in one molecule, a specific mono(meth)acrylic acid ester compound, an inorganic filler having an average primary particle diameter of 0.01 to 5 μm, and a polymerization initiator. Patent Document 2 discloses a dental photopolymerizable composition characterized by containing a radically polymerizable monomer, an α-diketone compound, an amine compound, a photoacid generator, and an α-alkylstyrene compound. Patent Document 3 discloses a method for producing a dental mill blank, which comprises bringing an inorganic filler molded body obtained by press-molding an inorganic filler into contact with a polymerizable monomer-containing composition to polymerize and cure the polymerizable monomer.

Prior Art Documents

Patent Documents

[0003] [Patent Document 1] International Publication No. 2020 / 218446 [Patent Document 2] Japanese Patent Application Laid-Open No. 2016-169180 [Patent Document 3] International Publication No. 2014 / 021343 [Summary of the Invention] [Problems to be Solved by the Invention]

[0004] By the way, for example, dental composite resins are required to have sufficient mechanical strength that can be replaced with natural teeth in the cured product after polymerization and curing, water resistance that can withstand long-term oral restoration, a gloss retention rate that does not lose gloss even due to abrasion by a toothbrush or the like in the oral cavity, and the like. In addition, in the paste state before polymerization and curing, it is also required to have operability suitable for filling operations into cavities using dental instruments or the like. Regarding dental mill blanks, characteristics such as sufficient mechanical strength that can be replaced with natural teeth and a gloss retention rate that does not lose gloss even due to abrasion by a toothbrush or the like in the oral cavity are required. However, as a result of investigations by the present inventors, it has been found that there is still room for further improvement in the gloss retention rate of the cured product obtained from the curable composition for dental restoration described in Patent Document 1. In addition, as a result of investigations by the present inventors, regarding the dental photo-polymerizable composition described in Patent Document 2, the α-alkylstyrene compound is likely to undergo depolymerization (the polymer decomposes and returns to the polymerizable monomer), and when blended as a polymerizable monomer (when the blending amount is large), the mechanical strength of the cured product obtained decreases, and it has also been confirmed that cracks may occur in the cured product. In addition, as a result of investigations by the present inventors, it has been found that there is still room for further improvement in terms of mechanical strength and appearance for the dental mill blank obtained by the method for producing a dental mill blank described in Patent Document 3. Therefore, an object of the present invention is to provide a curable composition for dental restoration in which the obtained cured product has high flexural strength and fracture toughness and is excellent in gloss retention rate.

Means for Solving the Problem

[0005] As a result of intensive research, the present inventors have found that the above problems can be solved by using a curable composition for dental restoration that satisfies specific requirements. That is, the present invention includes the following inventions. [1] A curable composition for dental restoration containing a (meth)acrylic acid ester compound (A) having two or more (meth)acryloyloxy groups in one molecule, an aromatic vinyl compound (B), an inorganic filler (C), and a polymerization initiator (D), wherein the aromatic vinyl compound (B) is represented by the following formula (I). [Chemical Formula] [In formula (I), X represents a substituted or unsubstituted aromatic hydrocarbon ring or a substituted or unsubstituted aromatic heterocyclic ring. The substituted aromatic hydrocarbon ring and the substituted aromatic heterocyclic ring represented by X may each independently have one or more substituents R 1 . The substituent R 1 is a halogen atom, a substituted or unsubstituted alkyl group having 1 to 20 carbon atoms, a substituted or unsubstituted alicyclic hydrocarbon group having 3 to 20 ring-forming atoms, a substituted or unsubstituted aromatic hydrocarbon group having 6 to 20 ring-forming atoms, a substituted or unsubstituted heterocyclic group having 3 to 20 ring-forming atoms, a group represented by *-OR 2 , a group represented by *-NR 3 R 4 , a group represented by *-C(=O)OR 5 , a group represented by *-O(C=O)R 6 , a group represented by *-SO3R 7 , a group represented by *-PR 8 R 9 , a group represented by *-B(OH)2, a substituted or unsubstituted silyl group, a nitro group, or a cyano group. R 2 、R 3 、R 4 、R 5 、R 6, R 7 , R 8 and R 9 each independently represents a hydrogen atom, a substituted or unsubstituted alkyl group having 1 to 10 carbon atoms, a substituted or unsubstituted alicyclic hydrocarbon group having 3 to 20 ring-forming atoms, or a substituted or unsubstituted aromatic hydrocarbon group having 6 to 20 ring-forming atoms. Each hydroxy group in the group represented by *-B(OH)2 may be substituted with a protecting group that is converted to a hydroxy group by deprotection. * each independently represents a bonding position with a ring-forming atom that forms an aromatic hydrocarbon ring represented by X or a ring-forming atom that forms an aromatic heterocyclic ring. When the aromatic hydrocarbon ring or aromatic heterocyclic ring represented by X has two or more substituents R 1 , the two or more substituents R 1 may be the same as each other or different from each other. When the aromatic hydrocarbon ring or aromatic heterocyclic ring represented by X has two or more substituents R 1 and at least two of the two or more substituents R 1 selected therefrom are substituted on adjacent ring-forming atoms, the two adjacent substituents R 1 may be bonded to each other to form a ring structure consisting only of carbon atoms and not containing an unsaturated bond, may form a ring structure containing carbon atoms and heteroatoms and not containing an unsaturated bond, or may not be bonded to each other to form a ring structure. [2] The curable composition for dental restoration according to [1] above, wherein the content of the aromatic vinyl compound (B) is 2 to 60% by mass in 100% by mass in total of the components (A) and (B). [3] In the formula (I), X is an aromatic hydrocarbon ring having one substituent R 1 or an unsubstituted aromatic hydrocarbon ring, or an aromatic heterocyclic ring having one substituent R 1 or an unsubstituted aromatic heterocyclic ring, the curable composition for dental restoration according to [1] or [2] above. [4] In the formula (I), when X represents a substituted aromatic hydrocarbon ring or a substituted aromatic heterocyclic ring, the substituent R1 at least one or all of which is a substituent R 1 The dental restorative curable composition according to any one of [1] to [3], wherein the substituent having an electron-donating property is among the substituents represented by R [5] The substituent having an electron-donating property is a substituted or unsubstituted alkyl group having 1 to 20 carbon atoms, *-OR 2 a group represented by, or *-NR 3 R 4 a group represented by. The dental restorative curable composition according to [4]. [6] In the formula (I), the number of ring-forming atoms forming the aromatic hydrocarbon ring in the substituted or unsubstituted aromatic hydrocarbon ring represented by X is 6 to 25. The dental restorative curable composition according to any one of [1] to [5]. [7] In the formula (I), the number of ring-forming atoms forming the aromatic heterocyclic ring in the substituted or unsubstituted aromatic heterocyclic ring represented by X is 5 to 20. The dental restorative curable composition according to any one of [1] to [6]. [8] In the formula (I), X is a substituted or unsubstituted benzene ring, a substituted or unsubstituted naphthalene ring, a substituted or unsubstituted anthracene ring, a substituted or unsubstituted fluorene ring, a substituted or unsubstituted phenanthrene ring, a substituted or unsubstituted pyrene ring, a substituted or unsubstituted furan ring, a substituted or unsubstituted thiophene ring, a substituted or unsubstituted pyrrole ring, a substituted or unsubstituted imidazole ring, a substituted or unsubstituted oxazole ring, a substituted or unsubstituted pyridine ring, a substituted or unsubstituted pyrazine ring, a substituted or unsubstituted pyrimidine ring, a substituted or unsubstituted pyridazine ring, a substituted or unsubstituted triazine ring, a substituted or unsubstituted benzofuran ring, a substituted or unsubstituted benzothiophene ring, a substituted or unsubstituted quinoline ring, a substituted or unsubstituted isoquinoline ring, a substituted or unsubstituted quinazoline ring, a substituted or unsubstituted indole ring, a substituted or unsubstituted carbazole ring, a substituted or unsubstituted dibenzofuran ring, and a substituted or unsubstituted dibenzothiophene ring, and is one selected from the group consisting of. The dental restorative curable composition according to any one of [1] to [7]. [9] In the formula (I), X is a substituted or unsubstituted benzene ring, and the dental restorative curable composition according to [8] above.

[10] The dental restorative curable composition according to any one of [1] to [9] above, wherein the average primary particle diameter of the inorganic filler (C) is 0.01 to 5 μm.

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

[10] above, wherein the content of the inorganic filler (C) is 50 to 95% by mass based on the total amount of the dental restorative curable composition.

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

[11] above, wherein the polymerization initiator (D) contains a photoinitiator.

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

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

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

[13] above, which is for dental composite resin.

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

[13] above, which is for dental mill blank. [Effect of the Invention]

[0006] According to the present invention, it is possible to provide a dental restorative curable composition in which the obtained cured product has high flexural strength and fracture toughness and is excellent in gloss retention rate. [Modes for Carrying Out the Invention]

[0007] Hereinafter, an example of an embodiment of the present invention (hereinafter, also referred to as "one aspect of the present invention") will be described. However, each of the embodiments shown below is an exemplification for embodying the technical idea of the present invention, and the present invention is not limited to the following description. Aspects arbitrarily selected from the matters described in this specification or aspects arbitrarily combined are also included in the present invention. In this specification, although preferred forms of embodiments are shown, combinations of two or more of the individual preferred forms are also preferred forms. The stipulation of being preferred can be arbitrarily selected. For example, it can be said that combinations of the stipulations of being preferred are more preferred. In this specification, unless otherwise specified, the description of "XX to YY" as a numerical range means "XX or more and YY or less" (XX represents the lower limit value and YY represents the upper limit value). For example, when simply described as "10 to 90" as a numerical range, it represents a range of 10 or more and 90 or less. In this specification, for numerical ranges (such as the content of each component, the content of each structural unit, values calculated therefrom, and each physical property, each condition in the manufacturing method, etc.), the lower limit value and the upper limit value described stepwise can be combined independently of each other. For example, from the description of "preferably 10 to 90, more preferably 30 to 60" for the same matter, it is also possible to combine the "preferred lower limit value (10)" and the "more preferred upper limit value (60)" to obtain "10 to 60". Also, for a numerical range, for example, based on the description of "preferably 10 to 90, more preferably 30 to 60", without particularly specifying the upper limit value, it is also possible to stipulate only the lower limit side as "10 or more" or "30 or more", and similarly, without particularly specifying the lower limit value, it is also possible to stipulate only the upper limit side as "90 or less" or "60 or less". The same applies when the upper end of the numerical range is "less than" or the lower limit is "more than". Similarly, for example, from the description of "preferably 10 or more, more preferably 30 or more" and "preferably 90 or less, more preferably 60 or less" for the same matter, it is also possible to combine the "preferred lower limit value (10)" and the "more preferred upper limit value (60)" to obtain "10 or more and 60 or less". Similarly, only the lower limit side can be defined as "10 or more" or "30 or more", and similarly, only the upper limit side can be defined as "90 or less" or "60 or less". The same applies when the descriptions of "or more" and "or less" in the above description are respectively described as "more than" and "less than". That is, for example, based on the description of "preferably more than 10 and less than 90, more preferably 30 or more and 60 or less", it is also possible to combine the respective upper and lower limits to obtain "more than 10 and 60 or less", "30 or more and less than 90". In this specification, unless otherwise specified, the notations "bending strength", "fracture toughness", and "gloss retention rate" refer to the properties of the cured product obtained from the curable composition for dental restoration, which is one aspect of the present invention, and specifically, the properties evaluated by the methods described in the examples. In this specification, unless otherwise specified, "mechanical strength" refers to "bending strength" and "fracture toughness". In this specification, unless otherwise specified, the notation "paste workability" refers to the properties of the curable composition for dental restoration, which is one aspect of the present invention, before curing, and specifically, the properties evaluated by the methods described in the examples. In this specification, the notation "(meth)acryl" is used in the sense of including both "methacryl" and "acryl". The same applies to notations similar to this, such as "(meth)acrylate", "(meth)acrylate", "(meth)acryloyloxy", etc. In this specification, the "polymerizable monomer" refers to a compound that can initiate a polymerization reaction by the action of a polymerization initiator (D) or the like to generate a polymer. The "polymerizable monomer" includes (meth)acrylate compounds (A) having two or more (meth)acryloyloxy groups in one molecule, aromatic vinyl compounds (B), and any monomer other than components (A) and (B).

[0008] [Hardenable Composition for Dental Restoration] The hardenable composition for dental restoration according to one embodiment of the present invention contains a (meth)acrylic acid ester compound (A) having two or more (meth)acryloyloxy groups in one molecule, an aromatic vinyl compound (B), an inorganic filler (C), and a polymerization initiator (D), and the aromatic vinyl compound (B) is represented by the following formula (I). [Chemical formula] [In formula (I), X represents a substituted or unsubstituted aromatic hydrocarbon ring or a substituted or unsubstituted aromatic heterocyclic ring. The substituted aromatic hydrocarbon ring represented by X and the substituted aromatic heterocyclic ring each independently may have one or more substituents R 1 . The substituent R 1 is a halogen atom, a substituted or unsubstituted alkyl group having 1 to 20 carbon atoms, a substituted or unsubstituted alicyclic hydrocarbon group having 3 to 20 ring-forming atoms, a substituted or unsubstituted aromatic hydrocarbon group having 6 to 20 ring-forming atoms, a substituted or unsubstituted heterocyclic group having 3 to 20 ring-forming atoms, a group represented by *-OR 2 , a group represented by *-NR 3 R 4 , a group represented by *-C(=O)OR 5 , a group represented by *-O(C=O)R 6 , a group represented by *-SO3R 7 , a group represented by *-PR 8 R 9 , a group represented by *-B(OH)2, a substituted or unsubstituted silyl group, a nitro group, or a cyano group. R 2 , R 3 , R 4 , R 5 , R 6 , R 7 , R 8 and R 9 each independently represent a hydrogen atom, a substituted or unsubstituted alkyl group having 1 to 10 carbon atoms, a substituted or unsubstituted alicyclic hydrocarbon group having 3 to 20 ring-forming atoms, or a substituted or unsubstituted aromatic hydrocarbon group having 6 to 20 ring-forming atoms. Each hydroxy group in the group represented by *-B(OH)2 may be substituted with a protecting group that is converted to a hydroxy group by deprotection. * each independently represents a ring-forming atom that forms the aromatic hydrocarbon ring represented by X, or the bonding position with a ring-forming atom that forms an aromatic heterocyclic ring. When the aromatic hydrocarbon ring or aromatic heterocyclic ring represented by X has two or more substituents R 1 the two or more substituents R 1 may be the same as each other or different from each other. When the aromatic hydrocarbon ring or aromatic heterocyclic ring represented by X has two or more substituents R 1 and at least two of the two or more substituents R 1 selected therefrom are substituted on adjacent ring-forming atoms, the two adjacent substituents R1 may be bonded to each other to form a ring structure consisting only of carbon atoms and not containing an unsaturated bond, a ring structure containing carbon atoms and heteroatoms and not containing an unsaturated bond, or may not be bonded to each other and not form a ring structure.

[0009] The reason why the effects of the present invention are obtained by the above configuration is not necessarily clear, but the present inventors presume as follows. Although it is known to incorporate fine particles to achieve the required abrasiveness of dental materials, a curable composition for dental restoration obtained by mixing the fine particles and a polymerizable monomer has a problem that its viscosity tends to be high and it tends to be sticky, that is, when filling a cavity with a dental instrument, the curable composition for dental restoration adheres to the dental instrument, resulting in poor operability. On the other hand, when a low-viscosity polymerizable monomer is used to improve the operability, the mechanical strength of the resulting cured product tends to be low. Here, by using the aromatic vinyl compound (B) represented by the general formula (I), the viscosity of the resulting curable composition for dental restoration can be suppressed to a low level, the operability of the curable composition for dental restoration is improved, and the resulting cured product exhibits high mechanical strength. In addition, since the cured product of the curable composition for dental restoration containing the aromatic vinyl compound (B) is excellent in surface hardness, it has high durability against toothbrush wear and can suppress the disappearance of glossiness, and is excellent in gloss retention rate. Furthermore, since the aromatic vinyl compound (B) has all three residues other than the aromatic ring on the vinyl group being hydrogen atoms, the steric hindrance and depolymerization during polymerization are suppressed, so that the generation of cracks during polymerization can be suppressed, and the appearance of the resulting cured product is also excellent. Hereinafter, the curable composition for dental restoration will be further described.

[0010] <(Meth)acrylic acid ester compound (A) having two or more (meth)acryloyloxy groups in one molecule> By using the (meth)acrylic acid ester compound (A) having two or more (meth)acryloyloxy groups in one molecule (also referred to as "component (A)" in the present specification), high flexural strength can be imparted. Component (A) 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 and the like. However, in order to further improve the flexural strength, a (meth)acrylic acid ester compound having a cyclic structure with a rigid skeleton is preferred. Examples of the (meth)acrylic acid ester compound having the cyclic structure include, for example, a (meth)acrylic acid ester compound (A-1) having an aromatic ring, a (meth)acrylic acid ester compound (A-2) having an alicyclic ring, and a (meth)acrylic acid ester compound (A-3) having a heterocyclic ring. Further, as the component (A), a compound (A-4) having no cyclic structure may be included.

[0011] Further, from the viewpoint that the bending strength can be further improved by π-π interaction with the aromatic vinyl compound (B) described later, the component (A) is more preferably a (meth)acrylic acid ester compound (A-1) having an aromatic ring, and still more preferably a (meth)acrylic acid ester compound having a bisphenol A skeleton. On the other hand, as the component (A), from the viewpoint that the paste workability and fracture toughness are better, it is preferable to include a compound (A-4) having no cyclic structure.

[0012] Examples of the aromatic ring of the (meth)acrylic acid ester compound (A-1) having an aromatic ring include a benzene ring, a naphthalene ring, an anthracene ring, etc. Examples of the skeleton containing the aromatic ring include a biphenyl skeleton, a benzophenone skeleton, a phenyl ether skeleton, a bisphenol A skeleton, etc. From the viewpoint of more excellent flexural strength when combined with the aromatic vinyl compound (B), it is preferable to have a bisphenol A skeleton. Examples of the (meth)acrylic acid ester compound (A-1) having an aromatic ring 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, the one with an average addition mole number of 2.6 of ethoxy groups (commonly known as "D2,6E")), 1,2-bis[3-(meth)acryloyloxy 2-hydroxypropoxyphenyl]ethane, 9,9-bis[4-(2-acryloyloxyethoxy)phenyl]fluorene, etc. 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, 2,2-bis[4-(meth)acryloyloxypolyethoxyphenyl]propane (for example, the one with an average addition mole number of 2.6 of ethoxy groups) having a bisphenol A skeleton are more preferable from the viewpoint of flexural strength after curing.

[0013] Examples of the alicyclic ring of the (meth)acrylic acid ester compound (A-2) having an alicyclic ring include a cyclopentane ring, a cyclohexane ring, a cycloheptane ring, a dicyclodecane ring, a tricyclodecane ring, an adamantane ring, an isobornyl ring, and the like. Examples of the (meth)acrylic acid ester compound (A-2) having an alicyclic ring include 1,4-cyclohexanedimethanol di(meth)acrylate, tricyclodecane dimethanol di(meth)acrylate, adamantyl di(meth)acrylate, adamantyl tri(meth)acrylate, and the like.

[0014] Examples of the heterocyclic ring of the (meth)acrylic acid ester compound (A-3) having a heterocyclic ring include heterocyclic rings containing only nitrogen atoms as heteroatoms such as a triazine ring, a carbazole ring, a pyrrolidine ring, and a piperidine ring; heterocyclic rings containing only oxygen atoms as heteroatoms such as a tetrahydrofuran ring, an oxane ring, a dioxane ring, and a dioxolane ring; heterocyclic rings containing oxygen atoms and nitrogen atoms as heteroatoms such as a morpholine ring; heterocyclic rings containing only sulfur atoms as heteroatoms such as a tetrahydrothiophene ring and a tetrahydrothiopyran ring, and heterocyclic rings containing sulfur atoms and nitrogen atoms as heteroatoms such as a thiazine ring and a thiazole ring. Examples of the (meth)acrylic acid ester compound (A-3) having a heterocyclic ring include ethoxylated isocyanuric acid tri(meth)acrylate, ε-caprolactone-modified tris(2-(meth)acryloyloxyethyl) isocyanurate, hydroxypivalaldehyde-modified trimethylolpropane di(meth)acrylate, and the like.

[0015] Examples of the (meth)acrylic acid ester compound (A-4) having no cyclic structure include aliphatic compound-based bifunctional (meth)acrylic acid ester compounds such as glycerol di(meth)acrylate, ethylene glycol di(meth)acrylate, diethylene glycol di(meth)acrylate, triethylene glycol di(meth)acrylate, propylene glycol di(meth)acrylate, butylene glycol di(meth)acrylate, neopentyl glycol di(meth)acrylate, 1,3-butanediol di(meth)acrylate, 1,5-pentanediol di(meth)acrylate, 1,6-hexanediol di(meth)acrylate, 1,10-decanediol di(meth)acrylate, 1,2-bis(3-methacryloyloxy-2-hydroxypropoxy)ethane, 2,2,4-trimethylhexamethylene bis(2-carbamoyloxyethyl) di(meth)acrylate, N-methacryloyloxyethyl acrylamide, and N-methacryloyloxypropylamide;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, 1,7-diacryloyloxy-2,2,6,6-tetra(meth)acryloyloxymethyl-4-oxaheptane and other trifunctional or higher (meth)acrylic acid ester compounds can be mentioned. 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-trimethylhexamethylene bis(2-carbamoyloxyethyl) dimethacrylate (commonly known as "UDMA"), 1,10-decanediol dimethacrylate (commonly known as "DD"), 2,2,4-trimethylhexamethylene bis(2-carbamoyloxyethyl) dimethacrylate, N-methacryloyloxyethyl acrylamide (commonly known as "MAEA") are preferable. From the viewpoint that when used in combination with the aromatic vinyl compound (B) described later, the balance of bending strength, fracture toughness, gloss retention rate, and paste workability is more likely to be good, UDMA is more preferable.; Component (A) may be used alone or in combination of two or more kinds.

[0016] From the viewpoint of good paste workability and bending strength, the weight average molecular weight (Mw) of component (A) is preferably 500 to 50,000, more preferably 750 to 30,000, and still more preferably 1,000 to 15,000. The weight average molecular weight (Mw) in this specification is the weight average molecular weight in terms of standard polystyrene determined by gel permeation chromatography (GPC) measurement.

[0017] The content of component (A) in the dental restorative curable composition is preferably 40% by mass or more, more preferably 45% by mass or more, still more preferably 50% by mass or more, even more preferably 55% by mass or more, and even more preferably 60% by mass or more in 100% by mass in total of component (A) and component (B). From the viewpoint of more excellent flexural strength, the content of component (A) in the dental restorative curable composition is preferably 98% by mass or less, more preferably 95% by mass or less, still more preferably 90% by mass or less, even more preferably 85% by mass or less, and even more preferably 80% by mass or less in 100% by mass in total of component (A) and component (B). Therefore, the content of component (A) in the dental restorative curable composition is preferably 40 to 98% by mass, more preferably 45 to 95% by mass in 100% by mass in total of component (A) and component (B). From the point that both paste workability and flexural strength are more excellent, it is still more preferably 50 to 90% by mass, even more preferably 55 to 85% by mass, and even more preferably 60 to 80% by mass.

[0018] <Aromatic vinyl compound (B)> The aromatic vinyl compound (B) (also referred to as "component (B)" in this specification) is used to reduce the viscosity of the obtained dental restorative curable composition and impart excellent paste workability, and to impart high fracture toughness and gloss retention rate to the cured product. By using component (B), the cured product of the obtained dental restorative curable composition is excellent in fracture toughness. In addition, since the cured product of component (B) is excellent in surface hardness, the cured product of the dental restorative curable composition containing component (B) has high durability against toothbrush wear and can suppress the disappearance of glossiness. As a result, the obtained cured product is excellent in gloss retention rate. Component (B) is represented by the following formula (I).

[0019]

Chemical formula

[0020] In the formula (I), X represents a substituted or unsubstituted aromatic hydrocarbon ring or a substituted or unsubstituted aromatic heterocyclic ring, preferably a substituted or unsubstituted aromatic hydrocarbon ring. The substituted aromatic hydrocarbon ring and the substituted aromatic heterocyclic ring represented by X may each independently have one or more substituents R 1 and may have. Further, the aromatic hydrocarbon ring of the substituted or unsubstituted aromatic hydrocarbon ring represented by X may be a monocyclic ring such as a benzene ring, or may be a condensed ring such as a naphthalene ring.

[0021] In the formula (I), the substituent R 1 is a halogen atom, a substituted or unsubstituted alkyl group having 1 to 20 carbon atoms, a substituted or unsubstituted alicyclic hydrocarbon group having 3 to 20 ring-forming atoms, a substituted or unsubstituted aromatic hydrocarbon group having 6 to 20 ring-forming atoms, a substituted or unsubstituted heterocyclic group having 3 to 20 ring-forming atoms, a group represented by *-OR 2 a group represented by *-NR 3 R 4 a group represented by *-C(=O)OR 5 a group represented by *-O(C=O)R 6 a group represented by *-SO3R 7 a group represented by *-PR 8 R 9 a group represented by *-B(OH)2, a substituted or unsubstituted silyl group, a nitro group, or a cyano group. R 2 R 3 R 4 R 5 R 6 R 7 R 8 R and R 9 each independently represent a hydrogen atom, a substituted or unsubstituted alkyl group having 1 to 10 carbon atoms, a substituted or unsubstituted alicyclic hydrocarbon group having 3 to 20 ring-forming atoms, or a substituted or unsubstituted aromatic hydrocarbon group having 6 to 20 ring-forming atoms. Each hydroxy group in the group represented by *-B(OH)2 may be substituted with a protecting group that is converted to a hydroxy group by deprotection. * independently represents a ring-forming atom that forms the aromatic hydrocarbon ring represented by X, or a bonding position with a ring-forming atom that forms an aromatic heterocyclic ring. Here, for the bonding position of the substituent R represented by *, for example, when X is a substituted aromatic hydrocarbon ring, the substituent R 1 is bonded to a carbon atom that forms the ring structure of the aromatic hydrocarbon ring. On the other hand, when X is a substituted aromatic heterocyclic ring, the substituent R 1 is bonded to an atom that forms the ring structure of the aromatic heterocyclic ring. Therefore, in this case, the substituent R 1 may be bonded to a carbon atom that forms the ring structure of the aromatic heterocyclic ring, or may be bonded to a heteroatom such as a nitrogen atom. 1 is bonded to a carbon atom that forms the ring structure of the aromatic heterocyclic ring, or may be bonded to a heteroatom such as a nitrogen atom. Therefore, in this specification, "substituent R 1 " means, when X is a substituted aromatic hydrocarbon ring or a substituted aromatic heterocyclic ring, a substituent directly bonded to an atom that forms the ring structure of the aromatic hydrocarbon ring or an atom that forms the ring structure of the aromatic heterocyclic ring. In other words, when X is a substituted aromatic hydrocarbon ring or a substituted aromatic heterocyclic ring, no substituent other than the substituent R 1 is directly bonded to an atom that forms the ring structure of the aromatic hydrocarbon ring or an atom that forms the ring structure of the aromatic heterocyclic ring.

[0022] In this specification, for example, in the notation of "alkyl group having 1 to 20 carbon atoms, which may be substituted or unsubstituted", "1 to 20 carbon atoms" refers to the number of carbon atoms constituting the unsubstituted alkyl group. Therefore, for example, in the case of a methyl group, the number of carbon atoms is 1. Also, when the methyl group has a substituent, for example, in the case of a substituted methyl group such as a chloromethyl group, a trifluoromethyl group, an aminomethyl group, or a cyanomethyl group, since these substituents are all those in which a hydrogen atom on the methyl group having 1 carbon atom is substituted by each substituent, the number of carbon atoms is all 1. Therefore, for example, even when the whole substituted methyl group, such as the cyanomethyl group, contains two carbon atoms, the number of carbon atoms is not 2 but 1.

[0023] In this specification, the "number of ring-forming atoms" refers to the number of atoms that form a structure in which atoms are circularly bonded, such as a monocyclic ring, a condensed ring, and a ring assembly. For example, it refers to the number of atoms that constitute the ring structure itself of a compound having such a structure, such as a monocyclic compound, a condensed ring compound, a cross-linked compound, a carbocyclic compound, and a heterocyclic compound. Therefore, the number of hydrogen atoms bonded to the atoms constituting the ring structure itself or the number of atoms contained in the substituent is 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. And, for example, the number of hydrogen atoms bonded to a benzene ring or the number of atoms constituting the substituent is not included in the number of ring-forming atoms that form the benzene ring. For example, when an alkyl group is bonded to a benzene ring, the number of carbon atoms of the alkyl group is not included in the number of ring-forming atoms of the benzene ring, so the number of ring-forming atoms of the benzene ring substituted by the alkyl group is 6.

[0024] In the formula (I), when the aromatic hydrocarbon ring or aromatic heterocyclic ring represented by X has two or more substituents R 1 the two or more substituents R 1 may be the same as each other or different from each other. When the aromatic hydrocarbon ring or aromatic heterocyclic ring represented by X has two or more substituents R 1 and at least two of the two or more substituents R 1 selected therefrom are substituted on adjacent ring-forming atoms, the two adjacent substituents R 1 may be bonded to each other to form a ring structure consisting only of carbon atoms and not containing an unsaturated bond, may form a ring structure containing carbon atoms and heteroatoms and not containing an unsaturated bond, or may not be bonded to each other and not form a ring structure.

[0025] In the formula (I), X is an aromatic hydrocarbon ring having one substituent R 1 or an unsubstituted aromatic hydrocarbon ring, or a substituent R 1Preferably, it is an aromatic heterocyclic ring or an unsubstituted aromatic heterocyclic ring having one.

[0026] In addition, the polymerization of the dental restorative curable composition is usually carried out by a radical reaction. However, the radical species generated from the (meth)acrylate compound is electrophilic due to the influence of the electron-withdrawing carbonyl group and shows a high reactivity with the electron-rich polymerizable group. Therefore, from the viewpoint of being rich in reactivity with an aromatic vinyl compound having a hydrogen atom or an electron-donating substituent bonded thereto and excellent in the fracture toughness of the cured product of the resulting dental restorative curable composition, in component (B), X is unsubstituted or the substituent R 1 preferably exhibits electron-donating properties. Therefore, in the formula (I), when X represents a substituted aromatic hydrocarbon ring or a substituted aromatic heterocyclic ring, at least one or all of the substituents R 1 are preferably substituents having electron-donating properties among the respective substituents represented by the substituent R 1 , and more preferably all of the substituents R 1 are substituents having electron-donating properties among the respective substituents represented by the substituent R 1 .

[0027] Examples of the substituent having electron-donating properties include a substituted or unsubstituted alkyl group having 1 to 20 carbon atoms, a group represented by *-OR 2 , or a group represented by *-NR 3 R 4 . Preferably, it is a substituted or unsubstituted alkyl group having 1 to 20 carbon atoms, or a group represented by *-OR 2 , and more preferably.

[0028] In addition, the radical reaction is affected by the steric structure of the compound, and the smaller the steric hindrance of the polymerizable group, the higher the reaction. Therefore, when X represents a substituted aromatic hydrocarbon ring or a substituted aromatic heterocyclic ring, the substituent R 1At least one of them is preferably substituted on the ring-forming atom at the position farthest from the ring-forming atom to which the vinyl group in the formula (I) is bonded. For example, when X is a substituted benzene ring, the substituent R is preferably at the para position with respect to the vinyl group in the formula (I). 1 It preferably has From a similar perspective, it is preferable that the X is an unsubstituted aromatic hydrocarbon ring or an unsubstituted aromatic heterocyclic ring.

[0029] In the formula (I), the number of ring-forming atoms forming the aromatic hydrocarbon ring in the substituted or unsubstituted aromatic hydrocarbon ring represented by X is preferably 6 to 25, more preferably 6 to 18, still more preferably 6 to 14, and even more preferably 6 to 10.

[0030] In the formula (I), the number of ring-forming atoms forming the aromatic heterocyclic ring in the substituted or unsubstituted aromatic heterocyclic ring represented by X is preferably 5 to 20, more preferably 5 to 13, still more preferably 5 to 10, and even more preferably 5 or 6.

[0031] Also, in the formula (I), X is preferably one selected from the group consisting of a substituted or unsubstituted benzene ring, a substituted or unsubstituted naphthalene ring, a substituted or unsubstituted anthracene ring, a substituted or unsubstituted fluorene ring, a substituted or unsubstituted phenanthrene ring, a substituted or unsubstituted pyrene ring, a substituted or unsubstituted furan ring, a substituted or unsubstituted thiophene ring, a substituted or unsubstituted pyrrole ring, a substituted or unsubstituted imidazole ring, a substituted or unsubstituted oxazole ring, a substituted or unsubstituted pyridine ring, a substituted or unsubstituted pyrazine ring, a substituted or unsubstituted pyrimidine ring, a substituted or unsubstituted pyridazine ring, a substituted or unsubstituted triazine ring, a substituted or unsubstituted benzofuran ring, a substituted or unsubstituted benzothiophene ring, a substituted or unsubstituted quinoline ring, a substituted or unsubstituted isoquinoline ring, a substituted or unsubstituted quinazoline ring, a substituted or unsubstituted indole ring, a substituted or unsubstituted carbazole ring, a substituted or unsubstituted dibenzofuran ring, and a substituted or unsubstituted dibenzothiophene ring; more preferably one selected from the group consisting of a substituted or unsubstituted benzene ring, a substituted or unsubstituted naphthalene ring, a substituted or unsubstituted fluorene ring, a substituted or unsubstituted anthracene ring, a substituted or unsubstituted phenanthrene ring, a substituted or unsubstituted pyrene ring, a substituted or unsubstituted furan ring, a substituted or unsubstituted thiophene ring, a substituted or unsubstituted pyrrole ring, a substituted or unsubstituted imidazole ring, a substituted or unsubstituted oxazole ring, a substituted or unsubstituted pyridine ring, a substituted or unsubstituted pyrazine ring, a substituted or unsubstituted pyrimidine ring, a substituted or unsubstituted pyridazine ring, a substituted or unsubstituted triazine ring, a substituted or unsubstituted benzofuran ring, a substituted or unsubstituted benzothiophene ring, a substituted or unsubstituted indole ring, a substituted or unsubstituted quinoline ring, a substituted or unsubstituted isoquinoline ring, and a substituted or unsubstituted quinazoline ring; still more preferably one selected from the group consisting of a substituted or unsubstituted benzene ring, a substituted or unsubstituted naphthalene ring, and a substituted or unsubstituted pyridine ring; and even more preferably a substituted or unsubstituted benzene ring.

[0032] Substituent R 1 Examples of the halogen atom represented by 1 include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom, and a fluorine atom or a chlorine atom is preferred.

[0033] Substituent R 1 The unsubstituted alkyl group having 1 to 20 carbon atoms in the substituted or unsubstituted alkyl group having 1 to 20 carbon atoms represented by 1 may be a linear alkyl group or a branched alkyl group. Also, the carbon number in the substituted or unsubstituted alkyl group having 1 to 20 carbon atoms represented by Substituent R 1 is preferably 1 to 10, more preferably 1 to 4, still more preferably 1 or 2, and even more preferably 1. Substituent R 1 Examples of the unsubstituted alkyl group having 1 to 20 carbon atoms in the substituted or unsubstituted alkyl group having 1 to 20 carbon atoms represented by 1 include a methyl group, an ethyl group, a linear or branched propyl group, a linear or branched butyl group, a linear or branched pentyl group, a linear or branched hexyl group, a linear or branched heptyl group, a linear or branched octyl group, a linear or branched nonyl group, a linear or branched decyl group, a linear or branched undecyl group, a linear or branched dodecyl group, a linear or branched tridecyl group, a linear or branched tetradecyl group, a linear or branched pentadecyl group, a linear or branched hexadecyl group, a linear or branched heptadecyl group, a linear or branched octadecyl group, a linear or branched nonadecyl group, or a linear icosyl group, etc. Among these alkyl groups, preferably a methyl group, an ethyl group, a linear or branched propyl group, a linear or branched butyl group, a linear or branched pentyl group, a linear or branched hexyl group, a linear or branched heptyl group, a linear or branched octyl group, a linear or branched nonyl group, or a linear or branched decyl group, more preferably a methyl group, an ethyl group, a propyl group, an isopropyl group, an n-butyl group, an isobutyl group, an s-butyl group, or a t-butyl group, still more preferably a methyl group or an ethyl group, and even more preferably a methyl group.

[0034] In addition, for example, examples of the substituted alkyl group include, for example, a halogenated alkyl group substituted with a halogen atom such as a chloroalkyl group or a fluoroalkyl group; an aminoalkyl group substituted with an amino group such as an aminomethyl group; a cyanoalkyl group substituted with a cyano group such as a cyanomethyl group; and the like. Specific examples of the halogenated alkyl group include, for example, a chloromethyl group, a dichloromethyl group, a trichloromethyl group, a fluoroalkyl group, a difluoroalkyl group, a trifluoromethyl group, and the like.

[0035] Substituent R 1 The number of ring-forming atoms in the substituted or unsubstituted alicyclic hydrocarbon group having 3 to 20 ring-forming atoms represented by is preferably 3 to 10, more preferably 3 to 8, and still more preferably 3 to 6. Substituent R 1 Examples of the unsubstituted alicyclic hydrocarbon group having 3 to 20 carbon atoms in the substituted or unsubstituted alicyclic hydrocarbon group having 3 to 20 ring-forming atoms represented by include, for example, a cyclopropyl group, a cyclobutyl group, a cyclopentyl group, a cyclohexyl group, a cycloheptyl group, a cyclooctyl group, a cyclononanil group, a cyclodecanyl group, a cycloundecanyl group, a cyclododecanyl group, a decahydronaphthyl group, a 1-adamantyl group, a 2-adamantyl group, a 1-norbornyl group, and a 2-norbornyl group. Among these, a cyclopentyl group, a cyclohexyl group, a 1-adamantyl group, and a 2-adamantyl group are preferable, a cyclopentyl group and a cyclohexyl group are more preferable, and a cyclohexyl group is still more preferable.

[0036] Substituent R 1 The number of ring-forming atoms in the substituted or unsubstituted aromatic hydrocarbon group having 6 to 20 ring-forming carbon atoms represented by is preferably 6 to 14, more preferably 6 to 10, and still more preferably 6. Substituent R 1Examples of the unsubstituted aromatic hydrocarbon group having 6 to 20 ring-forming carbon atoms represented by the substituted or unsubstituted aromatic hydrocarbon group include a phenyl group, a naphthyl group, an anthracenyl group, a fluorenyl group, a phenanthrenyl group, a pyrenyl group, a tetracenyl group, etc. Among these, a phenyl group and a naphthyl group are preferable, and a phenyl group is more preferable.

[0037] Substituent R 1 The number of ring-forming atoms in the substituted or unsubstituted heterocyclic group having 3 to 20 ring-forming atoms represented by is preferably 3 to 14, more preferably 5 to 13, still more preferably 5 to 10, and even more preferably 5 or 6. Substituent R 1 Examples of the unsubstituted heterocyclic group having 3 to 20 ring-forming atoms represented by the substituted or unsubstituted heterocyclic group having 3 to 20 ring-forming atoms include a furanyl group, a thiophenyl group (also referred to as a thienyl group), a pyrrolyl group, an imidazolyl group, an oxazolyl group, a pyridinyl group, a pyrazinyl group, a pyrimidinyl group, a pyridazinyl group, a triazinyl group, a benzofuranyl group, a benzothiophenyl group (also referred to as a benzothienyl group), a quinolinyl group (also referred to as a quinolyl group), an isoquinolinyl group (also referred to as an isoquinolyl group), a quinazolinyl group, an indolyl group, a carbazolyl group, a dibenzofuranyl group, and dibenzothiophene (also referred to as a dibenzothienyl group), etc. Among these, a furanyl group, a thiophenyl group, a pyrrolyl group, an imidazolyl group, a pyridinyl group, a pyrazinyl group, a pyrimidinyl group, a pyridazinyl group, and a triazinyl group are preferable, a furanyl group, a thiophenyl group, a pyrrolyl group, a pyridinyl group, and a triazinyl group are more preferable, and a thiophenyl group and a pyridinyl group are still more preferable.

[0038] R 2 、R 3 、R 4 、R 5 、R 6 、R 7 、R 8 and R 9Each independently represents a hydrogen atom, a substituted or unsubstituted alkyl group having 1 to 10 carbon atoms, a substituted or unsubstituted alicyclic hydrocarbon group having 3 to 20 ring-forming atoms, or a substituted or unsubstituted aromatic hydrocarbon group having 6 to 20 ring-forming atoms.

[0039] The *-OR 2 Examples of the group represented by are preferably a hydroxy group, a substituted or unsubstituted methoxy group, a substituted or unsubstituted ethoxy group, a substituted or unsubstituted propoxy group, a substituted or unsubstituted butoxy group, a substituted or unsubstituted cyclohexyloxy group; more preferably a hydroxy group, a substituted or unsubstituted methoxy group, a substituted or unsubstituted ethoxy group; still more preferably a hydroxy group, a substituted or unsubstituted methoxy group; even more preferably a substituted or unsubstituted methoxy group.

[0040] The *-NR 3 R 4 Examples of the group represented by are preferably an amino group, a monoalkylamino group, a dialkylamino group, a substituted or unsubstituted diarylamino group; more preferably an amino group, a methylamino group, a dimethylamino group, a diethylamino group, a diisopropylamino group, a substituted or unsubstituted diphenylamino group; still more preferably a dimethylamino group, a diethylamino group.

[0041] The *-C(=O)OR 5 Examples of the group represented by are preferably the group in which R 5 is represented by a hydrogen atom, a methyl group, an ethyl group, or an isopropyl group, and more preferably the group in which R 5 is a hydrogen atom or a methyl group. That is, a carboxy group represented by *-C(=O)OH or a group represented by *-C(=O)OCH3 is more preferable.

[0042] The *-O(C=O)R 6 Examples of the group represented by are preferably the group in which R 6 is represented by a methyl group, an ethyl group, or an isopropyl group, and more preferably the group in which R 6is a methyl group. That is, an acetoxy group represented by *-O(C=O)CH3 is more preferable.

[0043] The group represented by the said *-SO3R 7 As the group represented by, preferably, the said R 7 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 said R 7 is a group represented by a hydrogen atom, a sodium atom, or a methyl group, still more preferably, the said R 7 is a group represented by a hydrogen atom, or a methyl group.

[0044] The group represented by the said *-PR 8 R 9 As the group represented by, the said R 8 and R 9 are each independently, preferably, a substituted or unsubstituted alkyl group, or a substituted or unsubstituted aryl group, more preferably, a group represented by a methyl group, an n-butyl group, a phenyl group, or a 4-methoxyphenyl group, still more preferably, a group represented by a phenyl group, even more preferably, the said R 8 and R 9 are groups represented by phenyl groups together.

[0045] In addition, in the description of "each hydroxy group in the group represented by *-B(OH)2 may be substituted with a protecting group that is converted to a hydroxy group by deprotection", as a compound for forming the protecting group that is converted to the hydroxy group, for example, pinacol, 1,8-diaminonaphthalene, N-methyliminodiacetic acid, neopentyl glycol, pinandiol, catechol, 2-methyl-2-(2-methoxyphenyl)-1,3-butanediol and the like can be mentioned.

[0046] In addition, examples of the substituted or unsubstituted silyl group include a silyl group substituted with an alkyl group such as a methyl group, an ethyl group, a linear or branched propyl group, or a linear or branched butyl group; an alkoxy group such as a methoxy group, an ethoxy group, a propoxy group, or a butoxy group; an aryl group such as a phenyl group; or a halogen atom such as a chlorine atom on a silicon atom. For example, those substituted with two or three groups selected from the above substituents on a silicon atom can also be used. Examples of such a substituted or unsubstituted silyl group include a silyl group substituted with one, two, or three substituents selected from the group consisting of a silyl group, an unsubstituted alkyl group, an unsubstituted alkoxy group, and an unsubstituted aryl group. Examples of the silyl group substituted with one, two, or three substituents selected from the group consisting of the alkyl group, the alkoxy group, and the aryl group include a trimethylsilyl group, a triethylsilyl group, a tri-n-propylsilyl group, a triisopropylsilyl group, an ethyldimethylsilyl group, a propyldimethylsilyl group, an n-butyldimethylsilyl group, a t-butyldimethylsilyl group, a diethylisopropylsilyl group, a t-butyldiphenylsilyl group, a chlorodimethylsilyl group, a dichloromethylsilyl group, a trimethoxysilyl group, a triethoxysilyl group, a tripropoxysilyl group, a methyldimethoxysilyl group, a dimethylmethoxysilyl group, a methyldiethoxysilyl group, a dimethylethoxysilyl group, and the like. Among these, a trimethoxysilyl group, a triethoxysilyl group, a tripropoxysilyl group, a methyldimethoxysilyl group, a dimethylmethoxysilyl group, a methyldiethoxysilyl group, and a dimethylethoxysilyl group are preferable, a trimethoxysilyl group, a triethoxysilyl group, and a tripropoxysilyl group are more preferable, and a trimethoxysilyl group is even more preferable.

[0047] Also, X, substituent R 1 , R 2 , R 3 , R 4 , R 5 , R 6 , R 7 , R 8 and R 9In the case of "substituted or unsubstituted", the "any substituent" is not particularly limited as long as the effects of the present invention are achieved. For example, a halogen atom; an unsubstituted alkyl group having 1 to 20 carbon atoms; an unsubstituted alicyclic hydrocarbon group having 3 to 20 ring-forming carbon atoms; an unsubstituted aromatic hydrocarbon group having 6 to 20 ring-forming carbon atoms; an unsubstituted heterocyclic group having 3 to 20 ring-forming atoms; **-OR 12 a group represented by; **-NR 13 R 14 a group represented by; **-C(=O)OR 15 a group represented by; **-O(C=O)R 16 a group represented by; **-SO3R 17 a group represented by; **-PR 18 R 19 ; a group represented by -B(OH)2; an unsubstituted silyl group; a silyl group substituted with 1, 2, or 3 substituents selected from the group consisting of an unsubstituted alkyl group, an unsubstituted alkoxy group, and an unsubstituted aryl group; a nitro group; or; a cyano group.

[0048] R 12 R 13 R 14 R 15 R 16 R 17 R 18 and R 19 each independently represents a hydrogen atom, an unsubstituted alkyl group having 1 to 10 carbon atoms, an unsubstituted alicyclic hydrocarbon group having 3 to 20 ring-forming carbon atoms, or an unsubstituted aromatic hydrocarbon group having 6 to 20 ring-forming carbon atoms. Each hydroxy group in the group represented by **-B(OH)2 may be substituted with a protecting group that is converted to a hydroxy group by deprotection. In the description "each hydroxy group in the group represented by **-B(OH)2 may be substituted with a protecting group that is converted to a hydroxy group by deprotection", examples of the compound for forming the protecting group that is converted to the hydroxy group include pinacol, 1,8-diaminonaphthalene, N-methyliminodiacetic acid, neopentyl glycol, pinandiol, catechol, 2-methyl-2-(2-methoxyphenyl)-1,3-butanediol, and the like. Examples of the structure represented by *-BY include the same structure as that exemplified above. ** are each independently the aforementioned X, substituent R 1 , R 2 , R 3 , R 4 , R 5 , R 6 , R 7 , R 8 and R 9 represent the bonding positions of the atoms forming each ring or each group in the case of "unsubstituted" in the case of "substituted or unsubstituted" in X, R

[0049] In the formula (I), when X is represented by a substituted or unsubstituted aromatic hydrocarbon ring, and the aromatic hydrocarbon ring is a benzene ring, specific examples of the component (B) include styrene, 4-methylstyrene, 3-methylstyrene, 2-methylstyrene, 4-n-octylstyrene, 4-tert-butylstyrene, 2,4,6-trimethylstyrene, 4-methoxystyrene, 4-tert-butoxystyrene, 1-(1-ethoxyethoxy)-4-vinylbenzene, 4-aminostyrene, 3-aminostyrene, 4-vinylbenzylamine, 4-(chloromethyl)styrene, 3-(chloromethyl)styrene, 5-vinyl-1,3-benzodioxole, 4-vinylbiphenyl, 4-diphenyl(4-vinylphenyl)phosphine, trimethoxy(4-vinylphenyl)silane, 4-fluorostyrene, 3-fluorostyrene, 2-fluorostyrene, 2,3,4,5,6-pentafluorostyrene, 4-chlorostyrene, 3-chlorostyrene, 2-chlorostyrene, 4-bromostyrene, 3-bromostyrene, 2-bromostyrene, 4-vinylbenzoic acid, 3-vinylbenzoic acid, 2-vinylbenzoic acid, methyl 4-vinylbenzoate, methyl 3-vinylbenzoate, methyl 2-vinylbenzoate, 4-acetoxystyrene, 3-acetoxystyrene, 2-acetoxystyrene, 4-[(1-methylcyclohexyl)oxy]styrene, 4-trifluoromethylstyrene, 3-trifluoromethylstyrene, 4-cyanostyrene, 4-cyanomethylstyrene, 3-cyanomethylstyrene, 4-nitrostyrene, 3-nitrostyrene, 4-vinylphenylboronic acid, and 3-vinylphenylboronic acid and other aromatic vinyl compounds.Among these, preferably styrene, 4-methylstyrene, 3-methylstyrene, 2-methylstyrene, 4-n-octylstyrene, 4-tert-butylstyrene, 2,4,6-trimethylstyrene, 4-methoxystyrene, 4-acetoxystyrene, 4-tert-butoxystyrene, 1-(1-ethoxyethoxy)-4-vinylbenzene, 4-aminostyrene, 3-aminostyrene, 4-vinylbenzylamine, more preferably styrene, 4-methylstyrene, 3-methylstyrene, 2-methylstyrene, 2,4,6-trimethylstyrene, 4-methoxystyrene, 4-acetoxystyrene, still more preferably styrene, 4-methylstyrene, 2-methylstyrene, 2,4,6-trimethylstyrene, 4-methoxystyrene, and even more preferably styrene, 4-methylstyrene, 4-methoxystyrene.

[0050] In the formula (I), specific examples of the component (B) in which X is represented by a substituted or unsubstituted aromatic hydrocarbon ring and the aromatic hydrocarbon ring is a condensed ring include aromatic vinyl compounds such as 1-vinylnaphthalene, 2-vinylnaphthalene, 1-vinylpyrene, 4-vinylpyrene, 1-vinylanthracene, 2-vinylanthracene, 9-vinylanthracene, 9-(aminomethyl)-10-vinylanthracene, and 9-vinylphenanthrene. Among these, preferably 1-vinylnaphthalene, 2-vinylnaphthalene, 2-vinylanthracene, 9-vinylanthracene, 9-vinylphenanthrene, and more preferably 1-vinylnaphthalene, 2-vinylnaphthalene.

[0051] In the formula (I), specific examples of the component (B) in which X is represented by a substituted or unsubstituted aromatic heterocyclic ring include 4-vinylpyridine, 3-vinylpyridine, 2-vinylpyridine, 2-vinylfuran, 2-vinylthiophene, 3-vinylthiophene, 2-vinylpyrazine, 1-vinylimidazole, 1-vinyl-1H-pyrrole, 1-vinyl-1H-indole, 9- Examples include vinyl carbazole, 5-vinyl pyrimidine, 2-vinyl-4,6-diamino-1,3,3-triazine, 2-vinyl benzofuran, 2-vinyl quinoline, 4-vinyl quinoline, 6-vinyl quinazoline, and 2-vinyl dibenzothiophene. Among these, 4-vinyl pyridine, 3-vinyl pyridine, 2-vinyl pyridine, 2-vinyl furan, 2-vinyl thiophene, and 3-vinyl thiophene are preferred, 4-vinyl pyridine, 3-vinyl pyridine, and 2-vinyl pyridine are more preferred, and 4-vinyl pyridine is even more preferred.

[0052] Also, as described above, from the viewpoint of being more likely to improve the fracture toughness, component (B) is such that X is an unsubstituted aromatic hydrocarbon ring or an aromatic hydrocarbon ring having the substituent R 1 and the substituent R 1 preferably exhibits electron-donating properties. As such compounds, for example, among the specific compounds described above, styrene, 4-methylstyrene, 3-methylstyrene, 2-methylstyrene, 4-n-octylstyrene, 4-tert-butylstyrene, 2,4,6-trimethylstyrene, 4-methoxystyrene, 4-tert-butoxystyrene, 1-(1-ethoxyethoxy)-4-vinylbenzene, 4-aminostyrene, 3-aminostyrene, and 4-vinylbenzylamine are more preferred, styrene, 4-methylstyrene, 3-methylstyrene, 2-methylstyrene, 2,4,6-trimethylstyrene, and 4-methoxystyrene are further preferred, and styrene, 4-methylstyrene, 2,4,6-trimethylstyrene, and 4-methoxystyrene are even more preferred.

[0053] Also, as described above, from the viewpoint that a higher reaction is exhibited when the steric hindrance of the polymerizable group is smaller, for example, among the specific compounds described above, styrene, 4-methylstyrene, 4-n-octylstyrene, 4-tert-butylstyrene, 4-methoxystyrene, 4-tert-butoxystyrene, 1-(1-ethoxyethoxy)-4-vinylbenzene, 4-aminostyrene, 4-vinylbenzylamine, 4-(chloromethyl)styrene, 4-vinylbiphenyl, 4-diphenyl(4-vinylphenyl)phosphine, trimethoxy(4-vinylphenyl)silane, 4-fluorostyrene, 4-chlorostyrene, 4-bromostyrene, 4-vinylbenzoic acid, methyl 4-vinylbenzoate, 4-acetoxystyrene, 4-[(1-methylcyclohexyl)oxy]styrene, 4-trifluoromethylstyrene, 4-cyanostyrene, 4-cyanomethylstyrene, 4-nitrostyrene, and 4-vinylphenylboronic acid are preferable.

[0054] As component (B), from the viewpoint of facilitating the exhibition of the effects of the present invention, among the specific compounds described above, preferably, at least one selected from the group consisting of styrene, 4-methylstyrene, 2-methylstyrene, 4-n-octylstyrene, 4-tert-butylstyrene, 2,4,6-trimethylstyrene, 4-methoxystyrene, 4-tert-butoxystyrene, 1-(1-ethoxyethoxy)-4-vinylbenzene, 4-aminostyrene, 4-vinylbenzylamine, 4-(chloromethyl)styrene, 4-vinylbiphenyl, 4-diphenyl(4-vinylphenyl)phosphine, trimethoxy(4-vinylphenyl)silane, 4-fluorostyrene, 2,3,4,5,6-pentafluorostyrene, 4-chlorostyrene, 4-bromostyrene, 4-vinylbenzoic acid, methyl 4-vinylbenzoate, 4-acetoxystyrene, 4-[(1-methylcyclohexyl)oxy]styrene, 4-trifluoromethylstyrene, 4-cyanostyrene, 4-cyanomethylstyrene, 4-nitrostyrene, 1-vinylnaphthalene, 2-vinylnaphthalene, 1-vinylpyrene, 4-vinylpyrene, 1-vinylanthracene, 2-vinylanthracene, 9-vinylanthracene, 4-vinylpyridine, 3-vinylpyridine, 2-vinylpyridine, 2-vinylfuran, 2-vinylthiophene, and 3-vinylthiophene is preferred; More preferably, at least one selected from the group consisting of styrene, 4-methylstyrene, 2-methylstyrene, 2,4,6-trimethylstyrene, 4-methoxystyrene, 4-acetoxystyrene, 1-vinylnaphthalene, 2-vinylnaphthalene, and 4-vinylpyridine; Even more preferably, at least one selected from the group consisting of styrene, 4-methylstyrene, 4-methoxystyrene, 1-vinylnaphthalene, 2-vinylnaphthalene, and 4-vinylpyridine; Even more preferably, at least one selected from the group consisting of styrene, 4-methylstyrene, 4-methoxystyrene, 1-vinylnaphthalene, and 2-vinylnaphthalene.

[0055] Component (B) may be used alone or in combination of two or more.

[0056] The content of component (B) in the curable composition for dental restoration is preferably 2% by mass or more, more preferably 5% by mass or more, still more preferably 10% by mass or more, even more preferably 15% by mass or more, and even more preferably 20% by mass or more in 100% by mass in total of components (A) and (B). From the viewpoint of more excellent paste workability and fracture toughness, the content of component (B) in the curable composition for dental restoration is preferably 60% by mass or less, more preferably 55% by mass or less, still more preferably 50% by mass or less, even more preferably 45% by mass or less, and even more preferably 40% by mass or less in 100% by mass in total of components (A) and (B). Therefore, the content of component (B) in the curable composition for dental restoration is preferably 2 to 60% by mass, more preferably 5 to 55% by mass, still more preferably 10 to 50% by mass, even more preferably 15 to 45% by mass, and even more preferably 20 to 40% by mass in 100% by mass in total of components (A) and (B). From the viewpoint of more excellent balance of flexural strength, fracture toughness, gloss retention rate, and paste workability, the content of component (B) in the curable composition for dental restoration is preferably 2 to 60% by mass, more preferably 5 to 55% by mass, still more preferably 10 to 50% by mass, even more preferably 15 to 45% by mass, and even more preferably 20 to 40% by mass.

[0057] (Total content of components (A) and (B)) From the viewpoint that the effects of the present invention are more easily achieved, the total content of components (A) and (B) in the curable composition for dental restoration is preferably 90 to 100% by mass, more preferably 95 to 100% by mass, still 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 in 100% by mass in total of the polymerizable monomers contained in the curable composition for dental restoration. Further, the polymerizable monomer contained in the dental restorative curable composition may be substantially composed of only component (A) and component (B). Here, "the polymerizable monomer is substantially composed of only component (A) and component (B)" means that the content of other polymerizable monomers other than component (A) and component (B) is less than 10% by mass in the total 100% by mass of the polymerizable monomers contained in the dental restorative curable composition, preferably less than 5% by mass, more preferably less than 2% by mass, still more preferably less than 1% by mass, even more preferably less than 0.1% by mass, and even more preferably less than 0.01% by mass.

[0058] (Total content of polymerizable monomers) From the viewpoint of more easily achieving the effects of the present invention, the total content of the polymerizable monomers in the dental restorative curable composition is preferably 70% by mass or more, more preferably 80% by mass or more, still 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, still 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 in the total 100% by mass of the polymerizable monomer-containing composition. Also, as described above, these stepwise-described lower limit values and upper limit values can be combined independently. For example, in one aspect of the present invention, the total content of the polymerizable monomers in the dental restorative curable composition is preferably 70 to 99.999% by mass, more preferably 80 to 99.95% by mass, still 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 in the total 100% by mass of the polymerizable monomer-containing composition. In this specification, the "polymerizable monomer-containing composition" refers to a composition containing a polymerizable monomer, and in the dental restorative curable composition, it refers to the composition excluding the inorganic filler (C).

[0059] <Inorganic filler (C)> As the inorganic filler (C) (also referred to as "component (C)" in this specification), as long as the effects of the present invention can be achieved, known inorganic fillers used as fillers for dental composite resins can be used, and it is preferable to use inorganic particles. Examples of the inorganic particles include various glasses (for example, silicon dioxide (quartz, fused silica, silica gel, etc.), those containing silicon as a main component and containing boron and / or aluminum together with various heavy metals, etc.), 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), hydroxyapatite, and the like. In this specification, the "main component" refers to the component that is contained the most in the total amount of the reference content. Component (C) may be used alone or in combination of two or more.

[0060] Important physical properties desired for dental materials include transparency and X-ray contrast similar to natural teeth. Among these, transparency can be achieved by making the refractive indices of the polymer of the inorganic filler (C) and the polymerizable monomer as close as possible. On the other hand, X-ray contrast can be imparted by using, as the inorganic filler (C), an inorganic filler (such as an oxide) containing heavy metal elements such as zirconium, barium, titanium, lanthanum, and strontium. The refractive indices of such inorganic fillers containing heavy metal elements are usually high and are in the range of 1.5 to 1.65. In one aspect of the present invention, for example, since the refractive index of the cured product of component (A) constituting the polymerizable monomer forming the polymer is usually 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, even when combined with such an inorganic filler having a high refractive index with X-ray contrast, the refractive index difference can be adjusted to be small, and the transparency of the obtained dental material can be improved.

[0061] Examples of the inorganic filler with a high refractive index capable of imparting the above-described X-ray contrast include barium borosilicate glass (e.g., "E-3000" manufactured by Esstech; "8235", "GM27884", "GM39923", etc. manufactured by Schott), strontium borosilicate glass (e.g., "E-4000" manufactured by Esstech; "G018-093", "GM32087", etc. manufactured by Schott), lanthanum glass (e.g., "GM31684" manufactured by Schott), fluoroaluminosilicate glass (e.g., "G018-091", "G018-117", etc. manufactured by Schott), glass containing zirconia (e.g., "G018-310", "G018-159", etc. manufactured by Schott), glass containing strontium (e.g., "G018-163", "G018-093", "GM32087", etc. manufactured by Schott), glass containing zinc oxide (e.g., "G018-161" manufactured by Schott), glass containing calcium (e.g., "G018-309" manufactured by Schott), and the like.

[0062] There is no particular limitation on the shape of the component (C). For example, various shapes such as crushed shape, plate shape, scaly shape, fibrous shape (short fiber, long fiber, etc.), needle shape, whisker, spherical shape, etc. can be used. As long as the requirements of the present invention are satisfied, the component (C) may be a combination of different shapes among the above shapes.

[0063] The average primary particle diameter (D50) of component (C) is preferably from 0.01 to 5 μm. By using component (C) having an average primary particle diameter (D50) within this range, a curable composition for dental restoration excellent in the abrasiveness of the cured product can be obtained. From such a viewpoint, the average primary particle diameter (D50) of component (C) is more preferably 0.02 μm or more, still more preferably 0.04 μm or more, and more preferably 3 μm or less, still more preferably 2 μm or less. When the average primary particle diameter (D50) is larger than 0.01 μm, the mechanical strength tends to be good, and when it is smaller than 5 μm, the abrasiveness tends to be good. Also, as described above, the lower limit values and upper limit values described stepwise can be combined independently. For example, in one aspect of the present invention, the average primary particle diameter (D50) of component (C) is more preferably from 0.02 to 3 μm, still more preferably from 0.04 to 2 μm.

[0064] The average primary particle diameter (D50) of component (C) can be determined by a laser diffraction scattering method or observation of particles with an electron microscope. Specifically, the laser diffraction scattering method is convenient for measuring the particle diameter of particles of 0.1 μm or more, and electron microscope observation is convenient for measuring the particle diameter of particles of less than 0.1 μm. Note that the laser diffraction scattering method may be adopted for determining whether the particle diameter is 0.1 μm or more.

[0065] In the laser diffraction scattering method, for example, the average primary particle diameter (D50) can be determined by measuring with a laser diffraction particle size distribution measuring apparatus (for example, "SALD-2300" manufactured by Shimadzu Corporation) using an aqueous solution of 0.2% sodium hexametaphosphate as a dispersion medium.

[0066] In electron microscope observation, for example, a scanning transmission electron microscope (SEM) image of particles (e.g., "SU3500H-800NA type" manufactured by Hitachi High-Technologies Corporation) is taken, and the average primary particle diameter (D50) can be obtained by measuring the particle diameter of the particles observed within a unit field of view of the SEM image using image analysis type particle size distribution measurement software (e.g., "Mac-View" manufactured by Mountech Co., Ltd.). At this time, the particle diameter of the particles is determined as the equivalent circle diameter, which is the diameter of a circle having the same area as the area of the particle, and the average primary particle diameter (D50) is calculated from the number of particles and their particle diameters.

[0067] Component (C) is preferably one that has been surface-treated in advance with a surface treatment agent. By using the surface-treated component (C), the flexural strength can be further improved. When two or more components (C) are used, 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 a plurality of components (C) may be mixed in advance and surface-treated together.

[0068] 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 a phosphate group, a pyrophosphate group, a thiophosphate group, a phosphonic acid group, a sulfonic acid group, and a carboxylic acid group. When two or more surface treatment agents are used, it may be a single-layer surface treatment layer formed from a mixture of two or more surface treatment agents, or a multi-layer surface treatment layer in which a plurality of single-layer surface treatment layers are stacked. Also, as the surface treatment method, known methods can be used without particular limitation.

[0069] Examples of the organosilicon compound include compounds represented by R 10 n SiY (4-n) (wherein R10 is a substituted or unsubstituted hydrocarbon group having 1 to 12 carbon atoms, Y represents an alkoxy group having 1 to 4 carbon atoms, an acetoxy group, a hydroxyl group, a halogen atom or a hydrogen atom, n is an integer of 0 to 3, provided that when there are a plurality of R 10 and Y, they may be the same or different from each other).

[0070] Specifically, for example, methyltrimethoxysilane, dimethyldimethoxysilane, phenyltrimethoxysilane, diphenyldimethoxysilane, methyltriethoxysilane, dimethyldiethoxysilane, phenyltriethoxysilane, diphenyldiethoxysilane, isobutyltrimethoxysilane, vinyltrimethoxysilane, vinyltriethoxysilane, vinyltris(β-methoxyethoxy)silane, 3,3,3-trifluoropropyltrimethoxysilane, methyl-3,3,3-trifluoropropyldimethoxysilane, β-(3,4-epoxycyclohexyl)ethyltrimethoxysilane, γ-glycidoxypropyltrimethoxysilane, γ-glycidoxypropylmethyldiethoxysilane, γ-glycidoxypropyltriethoxysilane, γ-methacryloyloxypropylmethyldimethoxysilane, γ-methacryloyloxypropylmethyldiethoxysilane, N-β(aminoethyl)γ-aminopropylmethyldimethoxysilane, N-β(aminoethyl)γ-aminopropyltrimethoxysilane, N-β(aminoethyl)γ-aminopropyltriethoxysilane, γ-aminopropyltrimethoxysilane, γ-aminopropyltriethoxysilane, N-phenyl-γ-aminopropyltrimethoxysilane, γ-mercaptopropyltrimethoxysilane, trimethylsilanol, methyltrichlorosilane, methyldichlorosilane, dimethyldichlorosilane, trimethylchlorosilane, phenyltrichlorosilane, diphenyldichlorosilane, vinyltrichlorosilane, trimethylbromosilane, diethylsilane, vinyltriacetoxysilane, ω-(meth)acryloyloxyalkyltrimethoxysilane [(number of carbon atoms between (meth)acryloyloxy group and silicon atom: 3 to 12, e.g., γ-methacryloyloxypropyltrimethoxysilane, etc.], ω-(meth)acryloyloxyalkyltriethoxysilane [(number of carbon atoms between (meth)acryloyloxy group and silicon atom: 3 to 12, e.g., γ-methacryloyloxypropyltriethoxysilane, etc.)], and the like can be mentioned.

[0071] Among these, coupling agents having functional groups capable of copolymerizing with polymerizable monomers, such as ω-(meth)acryloyloxyalkyltrimethoxysilanes such as γ-methacryloyloxypropyltrimethoxysilane [(number of carbon atoms between (meth)acryloyloxy group and silicon atom: 3 to 12)], ω-(meth)acryloyloxyalkyltriethoxysilanes [(number of carbon atoms between (meth)acryloyloxy group and silicon atom: 3 to 12)], vinyltrimethoxysilane, vinyltriethoxysilane, vinyltriacetoxysilane, γ-glycidoxypropyltrimethoxysilane, etc. are preferably used.

[0072] Examples of the organic titanium compound include tetramethyl titanate, tetraisopropyl titanate, tetra-n-butyl titanate, butyl titanate dimer, tetra(2-ethylhexyl) titanate, etc.

[0073] Examples of the organic zirconium compound include zirconium isopropoxide, zirconium n-butoxide, zirconium acetylacetonate, zirconium acetate, etc.

[0074] Examples of the organic aluminum compound include aluminum acetylacetonate, aluminum organic acid salt chelate compounds, etc.

[0075] Regarding the acidic group-containing organic compound having at least one acidic group, for example, as the acidic group-containing organic compound containing a phosphate group, 2-ethylhexyl acid phosphate, stearyl acid phosphate, 2-(meth)acryloyloxyethyl dihydrogen phosphate, 3-(meth)acryloyloxypropyl dihydrogen phosphate, 4-(meth)acryloyloxybutyl dihydrogen phosphate, 5-(meth)acryloyloxypentyl dihydrogen phosphate, 6-(meth)acryloyloxyhexyl dihydrogen phosphate, 7-(meth)acryloyloxyheptyl dihydrogen phosphate, 8-(meth)acryloyloxyoctyl dihydrogen phosphate, 9-(meth)acryloyloxynonyl dihydrogen phosphate, 10-(meth)acryloyloxydecyl dihydrogen phosphate, 11-(meth)acryloyloxyundecyl dihydrogen phosphate, 12-(meth)acryloyloxydodecyl dihydrogen phosphate, 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)acryloyloxyoctyl] hydrogen phosphate, bis[9-(meth)acryloyloxynonyl] hydrogen phosphate, bis[10-(meth)acryloyloxydecyl] hydrogen phosphate, 1,3-di(meth)acryloyloxypropyl dihydrogen phosphate, 2-(meth)acryloyloxyethyl phenyl hydrogen phosphate, 2-(meth)acryloyloxyethyl-2-bromoethyl hydrogen phosphate, bis[2-(meth)acryloyloxy-(1-hydroxymethyl)ethyl] hydrogen phosphate, and their acid chlorides, their alkali metal salts, and their ammonium salts, etc. can be mentioned.

[0076] In addition, as the acidic group-containing organic compound having an acidic group such as a pyrophosphate group, a thiophosphate group, a phosphonic acid group, a sulfonic acid group, or a carboxylic acid group, for example, those described in International Publication No. 2012 / 042911 can be preferably used.

[0077] The surface treatment agent may be used alone or in combination of two or more. Further, in order to enhance the chemical bondability between the inorganic filler (C) and the polymerizable monomer and improve the flexural strength, it is more preferable to use an acidic group-containing organic compound having a functional group copolymerizable with the polymerizable monomer.

[0078] The amount of the surface treatment agent used is not particularly limited. For example, it is preferably 0.1 to 50 parts by mass, more preferably 1 to 25 parts by mass, and still more preferably 1 to 15 parts by mass with respect to 100 parts by mass of the inorganic filler before surface treatment.

[0079] The content of the component (C) in the dental restorative curable composition is not particularly limited, but in 100% by mass of the total amount of the dental restorative curable composition, it is preferably 50 to 95% by mass, more preferably 55 to 90% by mass, and still more preferably 60 to 85% by mass.

[0080] <Polymerization initiator (D)> Examples of the polymerization initiator (D) (also referred to as "component (D)" in this specification) include a thermal polymerization initiator, a photopolymerization initiator, and a chemical polymerization initiator. Component (D) may be used alone or in combination of two or more. It is preferable to contain at least one selected from the group consisting of the thermal polymerization initiator and the photopolymerization initiator. In one aspect of the present invention, component (D) preferably contains the thermal polymerization initiator. In one aspect of the present invention, component (D) preferably contains the photopolymerization initiator.

[0081] (Thermal polymerization initiator) Examples of the thermal polymerization initiator include organic peroxides and azo compounds. Examples of the organic peroxide include ketone peroxide, hydroperoxide, diacyl peroxide, dialkyl peroxide, peroxyketal, peroxyester, and peroxydicarbonate.

[0082] Examples of the ketone peroxide include methyl ethyl ketone peroxide, methyl isobutyl ketone peroxide, methyl cyclohexanone peroxide, and cyclohexanone peroxide. Examples of the hydroperoxide include 2,5-dimethylhexane-2,5-dihydroperoxide, diisopropylbenzene hydroperoxide, cumene hydroperoxide, t-butyl hydroperoxide, and 1,1,3,3-tetramethylbutyl hydroperoxide. Examples of the diacyl peroxide include acetyl peroxide, isobutyryl peroxide, benzoyl peroxide, decanoyl peroxide, 3,5,5-trimethylhexanoyl peroxide, 2,4-dichlorobenzoyl peroxide, and lauroyl peroxide. Examples of the dialkyl peroxide include di-t-butyl peroxide, dicumyl peroxide, t-butyl cumyl peroxide, 2,5-dimethyl-2,5-di(t-butylperoxy)hexane, 1,3-bis(t-butylperoxyisopropyl)benzene, and 2,5-dimethyl-2,5-di(t-butylperoxy)-3-hexyne. 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 peroxy ester include α-cumyl peroxy neodecanoate, t-butyl peroxy neodecanoate, t-butyl peroxy pivalate, 2,2,4-trimethylpentyl peroxy-2-ethylhexanoate, t-amyl peroxy-2-ethylhexanoate, t-butyl peroxy-2-ethylhexanoate, di-t-butyl peroxy isophthalate, di-t-butyl peroxy hexahydroterephthalate, t-butyl peroxy-3,3,5-trimethylhexanoate, t-butyl peroxy acetate, t-butyl peroxy benzoate, and t-butyl peroxy maleic acid, among others. Examples of the peroxydicarbonate include, for example, di-3-methoxy peroxydicarbonate, di-2-ethylhexyl peroxydicarbonate, bis(4-t-butylcyclohexyl) peroxydicarbonate, diisopropyl peroxydicarbonate, di-n-propyl peroxydicarbonate, di-2-ethoxyethyl peroxydicarbonate, and diallyl peroxydicarbonate, among others.

[0083] Among these organic peroxides, diacyl peroxide is preferably used in view of the overall balance of safety, storage stability, and radical generation ability, and among them, benzoyl peroxide is more preferably used.

[0084] Examples of the azo compound include, for example, 2,2'-azobis(isobutyronitrile), 2,2'-azobis(2,4-dimethylvaleronitrile), 4,4'-azobis(4-cyanovaleric acid), 1,1'-azobis(cyclohexane-1-carbonitrile), dimethyl-2,2'-azobis(isobutyrate), 2,2'-azobis(2-amidinopropane) dihydrochloride, and the like.

[0085] (Photoinitiator) Examples of the photoinitiator include, for example, (bis)acylphosphine oxides, α-diketones, coumarins, and the like.

[0086] Among the above-mentioned (bis)acylphosphine oxides, examples of acylphosphine oxides include 2,4,6-trimethylbenzoyldiphenylphosphine oxide, 2,6-dimethoxybenzoyldiphenylphosphine oxide, 2,6-dichlorobenzoyldiphenylphosphine oxide, 2,4,6-trimethylbenzoylmethoxyphenylphosphine oxide, 2,4,6-trimethylbenzoylethoxyphenylphosphine oxide, 2,3,5,6-tetramethylbenzoyldiphenylphosphine oxide, benzoyldi-(2,6-dimethylphenyl)phosphonate, and salts thereof.

[0087] Among the above-mentioned (bis)acylphosphine oxides, examples of bisacylphosphine oxides include bis(2,6-dichlorobenzoyl)phenylphosphine oxide, bis(2,6-dichlorobenzoyl)-2,5-dimethylphenylphosphine oxide, bis(2,6-dichlorobenzoyl)-4-propylphenylphosphine oxide, bis(2,6-dichlorobenzoyl)-1-naphthylphosphine oxide, bis(2,6-dimethoxybenzoyl)phenylphosphine oxide, bis(2,6-dimethoxybenzoyl)-2,4,4-trimethylpentylphosphine oxide, bis(2,6-dimethoxybenzoyl)-2,5-dimethylphenylphosphine oxide, bis(2,4,6-trimethylbenzoyl)phenylphosphine oxide, bis(2,5,6-trimethylbenzoyl)-2,4,4-trimethylpentylphosphine oxide, and salts thereof.

[0088] Among these (bis)acylphosphine oxides, 2,4,6-trimethylbenzoyldiphenylphosphine oxide, 2,4,6-trimethylbenzoylmethoxyphenylphosphine oxide, bis(2,4,6-trimethylbenzoyl)phenylphosphine oxide, and sodium 2,4,6-trimethylbenzoylphenylphosphine oxide are preferred.

[0089] Examples of the α-diketones include diacetyl, benzyl, camphorquinone, 2,3-pentanedione, 2,3-octanedione, 9,10-phenanthrenequinone, 4,4'-oxybenzyl, acenaphthenequinone and the like. Among these, camphorquinone is preferable.

[0090] Examples of the coumarins include 3,3'-carbonylbis(7-diethylaminocoumarin), 3-(4-methoxybenzoyl)coumarin, 3-thienoylcoumarin, 3-benzoyl-5,7-dimethoxycoumarin, 3-benzoyl-7-methoxycoumarin, 3-benzoyl-6-methoxycoumarin, 3-benzoyl-8-methoxycoumarin, 3-benzoylcoumarin, 7-methoxy-3-(p-nitrobenzoyl)coumarin, 3-(p-nitrobenzoyl)coumarin, 3,5-carbonylbis(7-methoxycoumarin), 3-benzoyl-6-bromocoumarin, 3,3'-carbonylbis-coumarin, 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-nitrobenzoyl)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-ethoxysinnamoyl)-7-methoxycoumarin, 3-(4-dimethylaminosinnamoyl)coumarin, 3-(4-diphenylaminosinnamoyl)coumarin, 3-[(3-dimethylbenzothiazol-2-ylidene)acetyl]coumarin, 3-[(1-methylnaphtho[1,2-d]thiazol-2-ylidene)acetyl]coumarin, 3,3'-carbonylbis(6-methoxycoumarin), 3,3'-carbonylbis(7-acetoxycoumarin), 3,3'-Carbonylbis(7-dimethylaminocoumarin), 3-(2-benzothiazoyl)-7-(diethylamino)coumarin, 3-(2-benzothiazoyl)-7-(dibutylamino)coumarin, 3-(2-benzimidazolyl)-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)aminocoumarin, 10-[3-[4-(dimethylamino)phenyl]-1-oxo-2-propenyl]-2,3,6,7-tetrahydro-1,1,7,7-tetramethyl-1H,5H,11H-[1]benzopyrano[6,7,8-ij]quinolizin-11-one, 10-(2-benzothiazoyl)-2,3,6,7-tetrahydro-1,1,7,7-tetramethyl-1H,5H,11H-[1]benzopyrano[6,7,8-ij]quinolin-11-one, and other compounds described in JP-A-9-3109 and JP-A-10-245525 are mentioned.,

[0091] Among the above-mentioned coumarin compounds, 3,3'-carbonylbis(7-diethylaminocoumarin) and 3,3'-carbonylbis(7-dibutylaminocoumarin) are preferred.,

[0092] Among the above-mentioned photoinitiators, 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 curable compositions for dental restoration.,

[0093] In addition, the above-mentioned photoinitiator may be able to perform photopolymerization more efficiently in a shorter time by further combining with a polymerization accelerator as needed., Examples of polymerization accelerators suitable for combination with the photoinitiator include tertiary amines, aldehydes, compounds having a thiol group, sulfinic acids, and sulfinates.,

[0094] Examples of the tertiary amine include N,N-dimethylaniline, N,N-dimethyl-p-toluidine, N,N-dimethyl-m-toluidine, N,N-diethyl-p-toluidine, N,N-dimethyl-3,5-dimethylaniline, N,N-dimethyl-3,4-dimethylaniline, N,N-dimethyl-4-ethylaniline, N,N-dimethyl-4-isopropylaniline, N,N-dimethyl-4-t-butylaniline, N,N-dimethyl-3,5-di-t-butylaniline, N,N-bis(2-hydroxyethyl)-3,5-dimethylaniline, N,N-di(2-hydroxyethyl)-p-toluidine, N,N-bis(2-hydroxyethyl)-3,4-dimethylaniline, N,N-bis(2-hydroxyethyl)-4-ethylaniline, N,N-bis(2-hydroxyethyl)-4-isopropylaniline, N,N-bis(2-hydroxyethyl)-4-t-butylaniline, N,N-bis(2-hydroxyethyl)-3,5-diisopropylaniline, 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, N-n-butyldiethanolamine, N-lauryl diethanolamine, triethanolamine, 2-(dimethylamino)ethyl methacrylate, N-methyldiethanolamine dimethacrylate, N-ethyldiethanolamine dimethacrylate, triethanolamine monomethacrylate, triethanolamine dimethacrylate, triethanolamine trimethacrylate, etc.

[0095] Examples of the aldehydes include dimethylaminobenzaldehyde, terephthalaldehyde, etc. Examples of the compound having a thiol group include 2-mercaptobenzoxazole, decanethiol, 3-mercaptopropyltrimethoxysilane, thio-benzoic acid, and the like.

[0096] Examples of the 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, calcium 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, calcium 2,4,6-triisopropylbenzenesulfinate, and the like. As the polymerization accelerator for the photopolymerization initiator, one kind may be used alone, or two or more kinds may be used in combination.

[0097] (Chemical polymerization initiator) As the chemical polymerization initiator, organic peroxides and amine-based; redox polymerization initiators such as organic peroxides, amines, and sulfinic acid (or its salt)-based are preferably used. When using a redox polymerization initiator, the oxidizing agent and the reducing agent are separately packaged, and it is necessary to mix the two immediately before use.

[0098] Examples of the oxidizing agent of the redox polymerization initiator include organic peroxides. The organic peroxides as the oxidizing agent of the redox polymerization initiator are not particularly limited, and known ones can be used. Specifically, the organic peroxides exemplified in the above heat polymerization initiator can be mentioned. Among the above-mentioned organic peroxides, diacyl peroxide is preferable from the comprehensive balance of safety, storage stability, and radical generation ability, and benzoyl peroxide is more preferable among them.

[0099] As the reducing agent of the redox polymerization initiator, for example, a tertiary aromatic amine having no electron-withdrawing group on the aromatic ring is used. Examples of the tertiary aromatic amine having no electron-withdrawing group on the aromatic ring include N,N-dimethylaniline, N,N-dimethyl-p-toluidine, N,N-dimethyl-m-toluidine, N,N-diethyl-p-toluidine, N,N-dimethyl-3,5-dimethylaniline, N,N-dimethyl-3,4-dimethylaniline, N,N-dimethyl-4-ethylaniline, N,N-dimethyl-4-isopropylaniline, N,N-dimethyl-4-t-butylaniline, N,N-dimethyl-3,5-di-t-butylaniline, N,N-bis(2-hydroxyethyl)-3,5-dimethylaniline, N,N-bis(2-hydroxyethyl)-p-toluidine, N,N-bis(2-hydroxyethyl)-3,4-dimethylaniline, N,N-bis(2-hydroxyethyl)-4-ethylaniline, N,N-bis(2-hydroxyethyl)-4-isopropylaniline, N,N-bis(2-hydroxyethyl)-4-t-butylaniline, N,N-bis(2-hydroxyethyl)-3,5-diisopropylaniline, N,N-bis(2-hydroxyethyl)-3,5-di-t-butylaniline.

[0100] The chemical polymerization initiator may be used in combination with a polymerization accelerator as necessary. The polymerization accelerator for the chemical polymerization initiator can be selected from polymerization accelerators used in the general industrial field, and among them, polymerization accelerators used in dental applications are preferably used. Specifically, amines, sulfinic acids and sulfinates, copper compounds, tin compounds, etc. can be mentioned. The polymerization accelerator for the chemical polymerization initiator may be used alone or in combination of two or more.

[0101] The amines used as the polymerization accelerator for the chemical polymerization initiator can be classified 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; tertiary aliphatic amines such as N-methyldiethanolamine, N-ethyldiethanolamine, N-n-butyldiethanolamine, N-lauryl diethanolamine, 2-(dimethylamino)ethyl methacrylate, N-methyldiethanolamine dimethacrylate, N-ethyldiethanolamine dimethacrylate, triethanolamine monomethacrylate, triethanolamine dimethacrylate, triethanolamine trimethacrylate, triethanolamine, trimethylamine, triethylamine, and tributylamine. Among these, from the viewpoints of the curability and storage stability of the composition, tertiary aliphatic amines are preferred, and among them, at least one selected from N-methyldiethanolamine and triethanolamine is more preferred.

[0102] Examples of the aromatic amine having an electron-withdrawing group on the aromatic ring, which is used as a polymerization accelerator for the chemical polymerization initiator, include tertiary aromatic amines having an electron-withdrawing group on the aromatic ring. Examples of the tertiary aromatic amine having an electron-withdrawing group on the aromatic ring, which is used as a polymerization accelerator for the chemical 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, 4-(N,N-dimethylamino)benzophenone, butyl 4-(N,N-dimethylamino)benzoate, etc. Among these, from the viewpoint of imparting excellent curability to the composition, at least one selected from the group consisting of N,N-di(2-hydroxyethyl)-p-toluidine, ethyl 4-(N,N-dimethylamino)benzoate, n-butoxyethyl 4-(N,N-dimethylamino)benzoate, and 4-(N,N-dimethylamino)benzophenone is preferably used.

[0103] Examples of the sulfinic acid and sulfinate used as a polymerization accelerator for the chemical polymerization initiator include those exemplified as the polymerization accelerator for the photopolymerization initiator, and sodium benzenesulfinate, sodium p-toluenesulfinate, and sodium 2,4,6-triisopropylbenzenesulfinate are preferred.

[0104] Examples of the copper compound used as a polymerization accelerator for the chemical polymerization initiator include copper acetylacetonate, cupric acetate, copper oleate, cupric chloride, cupric bromide, etc., which are preferably used.

[0105] Examples of the tin compound used as a polymerization accelerator for the chemical polymerization initiator include di-n-butyltin dimaleate, di-n-octyltin dimaleate, di-n-octyltin dilaurate, di-n-butyltin dilaurate, etc. Examples of suitable tin compounds are di-n-octyltin dilaurate and di-n-butyltin dilaurate.

[0106] Among the above polymerization initiators, for example, regarding dental composite resins, it is preferable to use the photoinitiator for simplicity when curing in the oral cavity. On the other hand, regarding dental mill blanks, it is preferable to use the heat polymerization initiator to increase the degree of polymerization and improve the strength.

[0107] The content of component (D) in the curable composition for dental restoration is not particularly limited as long as the effects of the present invention are achieved. However, from the viewpoint of the curability of the resulting composition, etc., it is preferably 0.001 to 30 parts by mass with respect to 100 parts by mass in total of the polymerizable monomers. When the content of component (D) is 0.001 part by mass or more with respect to 100 parts by mass in total of the polymerizable monomers, polymerization proceeds sufficiently and there is no risk of causing a decrease in mechanical strength, more preferably 0.05 part by mass or more, still more preferably 0.1 part by mass or more. On the other hand, when the content of component (D) is 30 parts by mass or less with respect to 100 parts by mass in total of the polymerizable monomers, sufficient mechanical strength can be obtained even when the polymerization performance of the polymerization initiator itself is low, and furthermore, there is no risk of precipitation from the composition, more preferably 20 parts by mass or less, still more preferably 10 parts by mass or less, even more preferably 5 parts by mass or less, even more preferably 2.0 parts by mass or less. Also, as described above, these stepwise-described lower limit values and upper limit values can be combined independently. For example, in one aspect of the present invention, the content of component (D) in the curable composition for dental restoration is preferably 0.001 to 30 parts by mass, more preferably 0.05 to 20 parts by mass, still more preferably 0.1 to 10 parts by mass, even more preferably 0.1 to 2.0 parts by mass with respect to 100 parts by mass in total of the polymerizable monomers.

[0108] Also, when using the polymerization accelerator, the content of the polymerization accelerator in the curable composition for dental restoration is not particularly limited as long as the effects of the present invention are achieved. However, it is preferably 0.001 to 30 parts by mass, more preferably 0.05 to 20 parts by mass, still 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 with respect to 100 parts by mass in total of the polymerizable monomers.

[0109] (Total content of components (A), (B) and (D)) From the viewpoint of making the effects of the present invention more easily exhibited, the total content of component (A), component (B) and component (D) in the curable composition for dental restoration is preferably 70.001% by mass or more, more preferably 80% by mass or more, still 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, still more preferably 99.9% by mass or less, even more preferably 99.8% by mass or less, and may be 100% by mass in 100% by mass of the total amount of the polymerizable monomer-containing composition. Also, as described above, the lower limit values and upper limit values described stepwise can be combined independently of each other. For example, in one aspect of the present invention, the total content of component (A), component (B), and component (D) in the curable composition for dental restoration is preferably 70.001 to 100% by mass, more preferably 80 to 99.99% by mass, still 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 100% by mass in 100% by mass of the total amount of the polymerizable monomer-containing composition, and may be 100% by mass. Here, each content related to the aforementioned components (A), (B) and (D) can independently take the aforementioned respective contents, but when the selected contents are combined, a combination in which the total content of components (A), (B) and (D) exceeds 100% by mass in 100% by mass of the total amount of the polymerizable monomer-containing composition is not included.

[0110] (Content of the polymerizable monomer-containing composition) The content of the polymerizable monomer-containing composition in the curable composition for dental restoration is preferably 5 to 50% by mass, more preferably 10 to 45% by mass, still more preferably 15 to 40% by mass in 100% by mass of the total amount of the curable composition for dental restoration from the viewpoint of making the effects of the present invention more easily exhibited.

[0111] <Other components> In addition to the components (A) to (D) and the polymerization accelerator which may be optionally contained, the dental restorative curable composition may contain other components as long as the effects of the present invention are achieved, depending on the purpose. Examples of the other components include pH adjusters, ultraviolet absorbers, antioxidants, colorants, pigments, antibacterial agents, X-ray contrast agents, thickeners, fluorescent agents, and the like. The other components may be used alone or in combination of two or more.

[0112] As the pigment, known pigments used in dental restorative curable compositions can be used without any limitation. Examples of the pigment include at least one selected from inorganic pigments and organic pigments. Examples of the inorganic pigment include chromates such as lead yellow, zinc yellow, and barium yellow; ferrocyanides such as ultramarine blue; sulfides such as vermilion, cadmium yellow, zinc sulfide, and cadmium red; sulfates such as barium sulfate, zinc sulfate, and strontium sulfate; oxides such as antimony white, zinc white, titanium white, red iron oxide, iron black, and chromium oxide; hydroxides such as aluminum hydroxide; silicates such as calcium silicate and ultramarine blue; and carbon such as carbon black and graphite. Examples of the organic pigment include nitro-based pigments such as naphthol green B and naphthol green Y; nitro-based pigments such as naphthol S and lysol fast yellow 2G; insoluble azo-based pigments such as permanent red 4R, brilliant fast scarlet, hansa yellow, and benzidine yellow; poorly soluble azo-based pigments such as lysol red, lake red C, and lake red D; soluble azo-based pigments such as brilliant carmine 6B, permanent red F5R, pigment scarlet 3B, and Bordeaux 10B; phthalocyanine-based pigments such as phthalocyanine blue, phthalocyanine green, and sky blue; basic dye-based pigments such as rhodamine lake, malachite green lake, and methyl violet lake; and acidic dye-based pigments such as peacock blue lake, eosin lake, and quinoline yellow lake. The pigment is appropriately selected according to the desired color tone and may be used alone or in combination of two or more.

[0113] When the curable composition for dental restoration contains a pigment, the content of the pigment in the curable composition for dental restoration is not particularly limited because it can be appropriately adjusted according to the desired color tone. However, based on 100 parts by mass of the curable composition for dental restoration, it is preferably 0.000001 part by mass or more, more preferably 0.00001 part by mass or more, and is preferably 5 parts by mass or less, more preferably 1 part by mass or less. Further, the content of the pigment is preferably 0.000001 to 5 parts by mass, more preferably 0.00001 to 1 part by mass, based on 100 parts by mass of the curable composition for dental restoration.

[0114] Also, when the curable composition for dental restoration contains other components, as long as the effects of the present invention are achieved, there is no particular limitation on the total content of the other components, and an amount that can obtain the necessary effects may be used. For example, the total content of the other components is preferably 0.000001 to 5 parts by mass, more preferably 0.00001 to 1 part by mass, based on 100 parts by mass of the curable composition for dental restoration.

[0115] <Method for producing a curable composition for dental restoration> Examples of the method for producing the curable composition for dental restoration include a production method including the following steps (1) to (2) in this order.

[0116] Step (1): Kneading step The kneading step is a step of performing a kneading operation. In a kneading machine container, components (A), (B), and (D) are charged to prepare a polymerizable monomer-containing composition, and then component (C) is further charged and kneaded to produce a paste-like composition. In this specification, hereinafter, the "polymerizable monomer-containing composition" refers to a composition containing at least one selected from components (A) and (B), and refers to the composition before mixing with component (C). The polymerizable monomer-containing composition preferably contains at least components (A) and (B), and more preferably contains components (A), (B), and (D). The method of kneading each component in the kneading process is not particularly limited as long as the effects of the present invention are achieved, and known methods can be adopted. For example, from the viewpoint of shortening the kneading time and preventing the occurrence of variations in the degree of dispersion of each component in the paste composition, it is preferable to knead while heating. The kneading temperature is preferably 40 to 60 °C. When it is 40 °C or higher, the effect of shortening the kneading time can be sufficiently obtained, and when it is 60 °C or lower, it is preferable because polymerization curing and deterioration of the composition during kneading can be prevented. Further, during kneading, a vacuum degassing treatment can be performed as necessary. At this time, the degree of vacuum is not particularly limited, but for example, in order to efficiently remove bubbles, the degree of vacuum is preferably 5 to 200 Torr. Also, the kneading of each of the above components is preferably performed in the dark or under yellow light.

[0117] Step (2): Degassing step The degassing step is a step of performing a degassing operation. After charging the paste composition obtained in the above step (1) into a degassing machine container, while removing the bubbles inside the paste composition by reducing the pressure, degassing is performed by extruding it out of the container while applying pressure. The degassing conditions are not particularly limited, but in order to efficiently remove bubbles and to suppress the separation of the polymerizable monomer-containing composition containing component (A), component (B), and component (D) from component (C), the degree of vacuum is preferably 5 to 200 Torr, and the decompression time is preferably 3 to 30 minutes. Also, the pressure when extruding out of the degassing machine container is preferably 0.5 to 5 MPa, and the pressurization time is preferably 3 to 30 minutes. Further, during degassing, a heat treatment can be performed as necessary. The temperature during degassing is not particularly limited, but for efficient removal of bubbles, it is preferably 40 to 60 °C. Also, the above degassing operation is preferably performed in the dark or under yellow light. The curable composition for dental restoration obtained by this production method is the same as that described in the column of the curable composition for dental restoration which is one aspect of the present invention, and its preferred aspect is also the same.

[0118] [Dental composite resin] A dental composite resin which is one aspect of the present invention contains the above curable composition for dental restoration. Since the dental composite resin contains the curable composition for dental restoration, the resulting cured product is excellent in flexural strength, fracture toughness, and gloss retention rate. In addition, the dental composite resin has good paste workability. Therefore, the curable composition for dental restoration, which is one aspect of the present invention, can be suitably used for dental composite resins. That is, as the curable composition for dental restoration, which is one aspect of the present invention, preferably, a curable composition for dental restoration for dental composite resins is exemplified. In addition, as one aspect of the present invention, there is mentioned the use of the curable composition for dental restoration, which is one aspect of the present invention, as a dental composite resin. The dental curable composition and its production method are the same as the aspects described in the column of the curable composition for dental restoration, which is one aspect of the present invention, and the preferred aspects are also the same. In addition, as the production method of the dental composite resin, a method similar to the production method including the steps (1) to (2) in this order can be used.

[0119] The dental composite resin contains the curable composition for dental restoration as an active ingredient, and preferably contains the curable composition for dental restoration as a main component. Here, the phrase "contains the curable composition for dental restoration as an active ingredient" means that the effect that the cured product of the dental composite resin is excellent in flexural strength, fracture toughness, and gloss retention rate is derived from the curable composition for dental restoration. In the dental composite resin, the content of the curable composition for dental restoration is preferably 50 to 100% by mass, more preferably 60 to 100% by mass, still more preferably 70 to 100% by mass, even more preferably 80 to 100% by mass, even more preferably 90 to 100% by mass, and may be 100% by mass, based on 100% by mass of the total amount of the dental composite resin.

[0120] [Dental mill blank] A dental mill blank, which is one aspect of the present invention, is obtained by curing the curable composition for dental restoration. Since the dental mill blank is a cured product obtained by curing the dental restorative curable composition, it is excellent in flexural strength, fracture toughness, and gloss retention rate. Further, the occurrence of cracks in the dental mill blank is also suppressed, and the appearance is good. Therefore, the dental restorative curable composition, which is one aspect of the present invention, can be suitably used for a dental mill blank. In other words, as a preferred aspect of the dental restorative curable composition, there is mentioned a dental restorative curable composition for a dental mill blank. Further, as one aspect of the present invention, there is mentioned the use for a dental mill blank of the dental restorative curable composition which is one aspect of the present invention.

[0121] The dental mill blank preferably contains, as an active ingredient, a component derived from the dental restorative curable composition, and preferably contains, as a main component, a component derived from the dental restorative curable composition. Here, "containing, as an active ingredient, a component derived from the dental restorative curable composition" means that the effects that the dental mill blank is excellent in flexural strength, fracture toughness, and gloss retention rate are derived from the dental restorative curable composition. Further, the "component derived from the dental restorative curable composition" is a component that is obtained by curing the dental restorative curable composition and is composed of, for example, a mixture of a cured product of the polymer monomer-containing composition and the 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, still more preferably 70 to 100% by mass, even more preferably 80 to 100% by mass, even more preferably 90 to 100% by mass, and may be 100% by mass, based on 100% by mass of the total amount of the dental mill blank. The method for producing the dental mill blank is not particularly limited. For example, there are mentioned a method (Method 1) of curing the dental restorative curable composition by thermal polymerization, or a method (Method 2) of bringing an inorganic filler molded body obtained by press-molding an inorganic filler into contact with a polymerizable monomer-containing composition and curing by thermal polymerization.

[0122] As the method 1, for example, it includes the following steps (3) to (4) in this order.

[0123] Step (3): Filling step The filling step is a step of filling a paste-like curable composition for dental restoration into a polymerization container. For example, in the step (2), it can also be filled into the polymerization container by applying a load with a cylinder and extruding it from the defoaming machine 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 still 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 preferable.

[0124] Step (4): Polymerization step (polymerization step in method 1) The polymerization step in method 1 is a step of curing the paste-like curable composition for dental restoration by a polymerization reaction. The container filled with the curable composition for dental restoration is placed in a chamber capable of making the overall pressure a predetermined pressure, pressurized and heated, and polymerized so that the pressure inside and outside the container becomes 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 as the pressure during polymerization, 0.2 to 4.0 MPa is preferable, 0.3 to 2.0 MPa is more preferable, and 0.4 to 0.9 MPa is still more preferable. Being within this pressure range can suppress cracks and bubbles while suppressing the manufacturing cost. Also, as the temperature during polymerization, 60 to 180 °C is preferable. Also, 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 heat polymerization initiator, more preferably τ - 20 °C to τ + 30 °C, and still more preferably τ - 15 °C to τ + 25 °C. Also, 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. Being within this time range can make it difficult for unreacted components to remain and can perform polymerization with higher manufacturing efficiency.

[0125] As the method 2, for example, the following steps (5) to (7) are included in this order.

[0126] Step (5): Pressing step The pressing step is a step of press-molding an inorganic filler to produce an inorganic filler molded body. There is no particular limitation on the method of press-molding the inorganic filler, and a known method can be adopted. As a specific method of press-molding, for example, a method of filling an inorganic filler into a press mold (die) of a desired size and applying pressure by uniaxial pressing using an upper punch and a lower punch can be mentioned. The press pressure during uniaxial pressing can be appropriately set to an optimal value depending on the size of the target inorganic filler molded body, the type and particle size of the inorganic filler, etc., and can be, for example, 10 MPa or more. The higher the press pressure during the uniaxial pressing, the easier it is to obtain the desired dental mill blank, and the stability of the inorganic filler molded body when the inorganic filler molded body and the polymerizable monomer-containing composition are brought into contact is improved, which is preferable. However, considering the size of the inorganic filler molded body, productivity such as equipment factors, and suppression of cracks and chips in the inorganic filler molded body due to friction with the mold due to excessive load, etc., the press pressure during the uniaxial pressing is preferably, for example, 200 MPa or less. From the above-mentioned viewpoints, the press pressure during the uniaxial pressing is preferably 10 to 200 MPa, more preferably 20 to 180 MPa, and still more preferably 25 to 150 MPa. The pressing time during uniaxial pressing can be appropriately set according to the press pressure, but is preferably 1 to 120 minutes.

[0127] As another method other than the uniaxial press, for example, press molding may be performed by cold isostatic pressing (CIP). In this case, only the CIP may be adopted, or both a pressing method other than the method by CIP such as the aforementioned uniaxial press and the pressing method by CIP may be adopted. More specifically, press molding may be performed by CIP without performing the aforementioned uniaxial press, or press molding may be further performed by CIP after the press molding in the aforementioned uniaxial press. In press molding by CIP, usually, a higher press pressure can be applied than in the uniaxial press, and pressure can be applied evenly from three-dimensional directions to the inorganic filler compact. Therefore, by performing press molding by CIP, undesirable minute voids inside the inorganic filler compact and unevenness in the aggregated state of the inorganic filler can be eliminated. Also, for the same reason, by performing press molding by CIP, the compression density of the inorganic filler is further improved, and a dental mill blank with a higher content of the inorganic filler can be obtained. When press molding is performed by CIP without performing the uniaxial press, the inorganic filler is filled in an elastic container such as silicone rubber or polyisoprene rubber, and this is used as it is or in a depressurized state (including a vacuum state), and then press molding by CIP can be performed. Also, when press molding is further performed by CIP after the press molding in the uniaxial press, the compact obtained by the uniaxial press is used as it is or in a depressurized state (including a vacuum state), and then press molding by CIP can be performed. It is also preferable that the pressure during press molding by CIP is higher. For press molding by CIP, for example, a CIP device capable of applying pressure up to about 1,000 MPa manufactured by Kobe Steel, Ltd. can be used. The pressure during CIP is preferably higher regardless of the presence or absence of the uniaxial press because a desired dental mill blank is easily obtained and the stability of the inorganic filler compact when bringing the obtained inorganic filler compact into contact with the polymerizable monomer-containing composition is improved. From such a viewpoint, the pressure during CIP is preferably 30 MPa or more, more preferably 50 MPa or more, and still more preferably 100 MPa or more.Then, considering aspects such as productivity and suppression of cracks and chipping in the inorganic filler compact 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 described above, these stepwise-described lower and upper limit values can be combined independently. For example, in one aspect of the present invention, the pressure during the CIP is preferably 30 to 500 MPa, more preferably 50 to 450 MPa, and even more preferably 100 to 400 MPa. The pressurization time when performing CIP can be appropriately set according to the press pressure, but is preferably 1 to 120 minutes.

[0128] Step (6): Impregnation step The impregnation step is a step of bringing the inorganic filler compact obtained in step (5) into contact with the polymerizable monomer-containing composition, and the polymerizable monomer-containing composition is allowed to penetrate into the gaps of the inorganic filler compact so as to obtain a dental restorative curable composition having a structure in which the inorganic filler is extremely densely dispersed in the polymerizable monomer-containing composition. From such a viewpoint, in Method 2, it is preferable to use an inorganic filler compact that is not a sintered and interconnected porous body. The method of bringing the inorganic filler formed body into contact with the polymerizable monomer-containing composition is not particularly limited, and a method capable of allowing the polymerizable monomer-containing composition to penetrate into the gaps of the inorganic filler can be adopted. For example, from the viewpoint of simplicity, etc., a method of immersing the inorganic filler formed body in the polymerizable monomer-containing composition can preferably be adopted. By this immersion, due to capillary action, the polymerizable monomer-containing composition can gradually penetrate into the inorganic filler formed body. When the surrounding environment at this time is under a reduced pressure atmosphere, it is preferable because the penetration of the liquid polymerizable monomer-containing composition is promoted. Further, by repeating the operation of returning to the normal pressure atmosphere after the reduced pressure atmosphere (reduced pressure / normal pressure operation) a plurality of times, the penetration of the polymerizable monomer-containing composition can be further promoted, and the time until the polymerizable monomer-containing composition completely penetrates into the inorganic filler formed body can be shortened, so it is preferable. The degree of reduced pressure in the reduced pressure atmosphere can be appropriately adjusted according to the viscosity of the polymerizable monomer-containing composition, the particle diameter of the inorganic filler, etc. For example, it is preferably 0.1 Pa to 10 kPa, more preferably 1 Pa to 5 kPa, and still more preferably 10 Pa to 2 kPa or less. Further, the reduced pressure atmosphere may be a vacuum (for example, about 1×10 -8 ~1×10 -1 Pa). Also, since the penetration of the polymerizable monomer-containing composition into the inorganic filler formed body can be carried out more efficiently, and the polymerizable monomer-containing composition can penetrate into the inorganic filler formed body without gaps, a method of placing the seemingly polymerizable monomer-containing composition-impregnated inorganic filler formed body obtained by immersing the inorganic filler formed body in the polymerizable monomer-containing composition as described above under pressurized conditions for a certain period of time may be adopted. As the method of pressurization, for example, a CIP device or the like can be used. The pressure during pressurization is preferably 20 MPa or more, more preferably 50 MPa or more, and still more preferably 100 MPa or more. Also, the operation of returning to normal pressure after pressurization (pressurization / normal pressure operation) may be repeated a plurality of times. Also, the temperature at which the inorganic filler molded body is brought into contact with the polymerizable monomer-containing composition is preferably 0°C or higher, more preferably 10°C or higher, still more preferably 20°C or higher, and may also be 30°C or higher, 40°C or higher, or even 50°C or higher, because the penetration of the polymerizable monomer-containing composition into the inorganic filler molded body can be carried out more efficiently. Also, as described above, the lower limit and upper limit values described stepwise can be combined independently. For example, in one aspect of the present invention, the temperature at which the inorganic filler molded body is brought into contact with the polymerizable monomer-containing composition is preferably 0 to 80°C, more preferably 10 to 70°C, still 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. Also, the contact time when the inorganic filler molded body is brought into contact with the 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, the contact method, etc., and can be adjusted as appropriate. For example, when adopting the method of immersing the inorganic filler molded body in the polymerizable monomer-containing composition, the contact time can be, for example, 0.1 to 240 hours. In particular, when immersing under a reduced pressure atmosphere, the contact time can be, for example, 0.5 to 120 hours. On the other hand, when adopting the method of applying pressure to the inorganic filler molded body to feed the polymerizable monomer-containing composition into the inorganic filler molded body, the contact time can be, for example, 0.2 to 48 hours.

[0129] Step (7): Polymerization step (polymerization step in Method 2) In the polymerization step (Method 2) in Method 2, an inorganic filler molded body and a polymerizable monomer-containing composition are brought into contact with each other so that the polymerizable monomer-containing composition penetrates into the inorganic filler molded body (a state in which the polymerizable monomer-containing composition is impregnated), and the polymerizable monomer contained in the polymerizable monomer-containing composition is polymerized and cured. The temperature during polymerization is preferably 60 to 180°C. Further, from the viewpoint of exhibiting higher mechanical strength, the temperature during polymerization is preferably adjusted according to the 10-hour half-life temperature (τ) of the heat polymerization initiator, more preferably τ - 20°C to τ + 30°C, and even 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 even 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.

[0130] <Use of the curable composition for dental restoration> The curable composition for dental restoration, which is one aspect of the present invention, is excellent in the operability of the paste, the cured product has high flexural strength and fracture toughness, and excellent gloss retention rate, so it can be suitably used as a dental material. Specifically, in the field of dental medicine, it can be suitably used as a dental material (particularly dental composite resin) that can replace a part or the whole of a natural tooth. Further, the cured product obtained by polymerizing and curing the curable composition for dental restoration, which is one aspect of the present invention, can also be suitably used as a dental milling blank, which is a material to be cut used in a CAD / CAM system manufactured by cutting with a milling device.

Examples

[0131] Hereinafter, the present embodiment will be described more specifically with reference to Examples and Comparative Examples, but the present embodiment is not limited to the following Examples.

[0132] The abbreviations of the various components used in the Examples and Comparative Examples are as follows. [Component (A): (Meth)acrylic acid ester compound (A) having two or more (meth)acryloyloxy groups in one molecule] UDMA: [2,2,4-Trimethylhexamethylene bis(2-carbamoyloxyethyl)] dimethacrylate (manufactured by Kyoeisha Chemical Co., Ltd.) D2,6E: 2,2-Bis[4-methacryloyloxypolyethoxyphenyl] propane (average number of moles of added ethoxy groups: 2.6) (manufactured by Shin-Nakamura Chemical Co., Ltd.) Bis-GMA: 2,2-Bis[4-(3-methacryloyloxy-2-hydroxypropoxy)phenyl] propane (manufactured by Shin-Nakamura Chemical Co., Ltd.) TEGDMA: Triethylene glycol dimethacrylate (manufactured by Shin-Nakamura Chemical Co., Ltd.)

[0133] [Component (B): Aromatic vinyl compound (B)] St: Styrene 4-Me-St: 4-Methylstyrene 2-Me-St: 2-Methylstyrene 4-OMe-St: 4-Methoxystyrene 4-Ac-St: 4-Acetoxystyrene 2,4,6-TMe-St: 2,4,6-Trimethylstyrene 1-Vinyl-Nap: 1-Vinylnaphthalene 2-Vinyl-Nap: 2-Vinylnaphthalene 4-Vinyl-Py: 4-Vinylpyridine

[0134] [Aromatic vinyl compounds other than component (B)] MS: α-Methylstyrene

[0135] [Mono(meth)acrylate ester compound] POB-A: m-Phenoxybenzyl acrylate

[0136] [Component (C): Inorganic filler (C)] UF2.0: Barium borosilicate glass (average primary particle diameter (D50): 2.0 μm, "GM27884UF2.0" manufactured by Shot Co., Ltd.) UF1.5: Barium borosilicate glass (average primary particle diameter (D50) 1.5 μm, "GM27884UF1.5" manufactured by Schott) NF180: Barium borosilicate glass (average primary particle diameter (D50) 0.180 μm, "GM27884NF180" manufactured by Schott) Ox50: Fine particle silica (average primary particle diameter (D50) 0.040 μm, "AEROSIL (registered trademark) OX50" manufactured by Nippon Aerosil Co., Ltd.)

[0137] [Surface treatment agent] γ-MPS: γ-Methacryloyloxypropyltrimethoxysilane (manufactured by Shin-Etsu Chemical Co., Ltd.)

[0138] [Component (D): Polymerization initiator (D)] <Photoinitiator> 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-Tetramethylbutyl hydroperoxide (manufactured by NOF Corporation) BPO: Benzoyl peroxide (manufactured by NOF Corporation)

[0139] [Polymerization accelerator] JJA: Ethyl 4-(N,N-dimethylamino)benzoate MDEOA: N-Methyldiethanolamine

[0140] [Photoacid generator] IPDPI: p-Isopropylphenyl-p-methylphenyliodonium tetrakispentafluorophenylborate

[0141] The polymerizable monomer compositions used in the examples and comparative examples were produced by the following method. The compositions of the produced polymerizable monomer-containing compositions are shown in Tables 1 and 2 below. [Production Example 1] To 70 parts by mass of UDMA and 30 parts by mass of St, 0.2 part by mass of CQ as a photopolymerization initiator, 0.25 part by mass of TPP, 0.3 part by mass of JJA as a polymerization accelerator were added and dissolved under yellow light at 40 °C to prepare a polymerizable monomer-containing composition (EM1).

[0142] [Production Examples 2 to 13] Each component was blended so as to have the contents shown in Tables 1 and 2 below, and in the same manner as in Production Example 1, polymerizable monomer-containing compositions (EM2) to (EM13) were prepared.

[0143] [Production Example 14] To 70 parts by mass of UDMA and 30 parts by mass of St, 0.5 part by mass of THP as a thermal polymerization initiator was added and dissolved under yellow light at 40 °C to prepare a polymerizable monomer-containing composition (EM14).

[0144] [Production Example 15] To 70 parts by mass of UDMA and 30 parts by mass of 4-OMe-St, 0.5 part by mass of THP as a thermal polymerization initiator was added and dissolved under yellow light at 40 °C to prepare a polymerizable monomer-containing composition (EM15).

[0145] [Production Example 16] To 70 parts by mass of D2,6E and 30 parts by mass of POB-A, 0.2 part by mass of CQ as a photopolymerization initiator, 0.25 part by mass of TPP, 0.3 part by mass of JJA as a polymerization accelerator were added and dissolved under yellow light at 40 °C to prepare a polymerizable monomer-containing composition (CM1).

[0146] [Production Example 17] To 60 parts by mass of Bis-GMA and 40 parts by mass of TEGDMA, 0.3 part by mass of MS as an α-alkylstyrene compound, 0.3 part by mass of CQ as a photopolymerization initiator, 0.15 part by mass of JJA as a polymerization accelerator, 0.3 part by mass of MDEOA, 0.75 part by mass of IPDPI as a photoacid generator were added and dissolved under yellow light at 40 °C to prepare a polymerizable monomer-containing composition (CM2).

[0147] [Production Example 18] To 70 parts by mass of UDMA, 30 parts by mass of MS as an α-alkylstyrene compound, 0.2 parts by mass of CQ as a photoinitiator, 0.25 parts by mass of TPP, and 0.3 parts by mass of JJA as a polymerization accelerator were added and dissolved under yellow light at 40 °C to prepare a polymerizable monomer-containing composition (CM3).

[0148] [Production Example 19] To 70 parts by mass of UDMA and 30 parts by mass of MS, 0.5 parts by mass of THP as a thermal polymerization initiator was added and dissolved under yellow light at 40 °C to prepare a polymerizable monomer-containing composition (CM4).

[0149] [Production Example 20] To 70 parts by mass of UDMA and 30 parts by mass of TEGDMA, 1.5 parts by mass of BPO as a thermal polymerization initiator was added and dissolved under yellow light at 40 °C to prepare a polymerizable monomer-containing composition (CM5).

[0150] The compositions of the polymerizable monomer-containing compositions obtained in the above production examples are shown in Tables 1 and 2 below.

[0151] [Table 1]

[0152] [Table 2]

[0153] The inorganic fillers used in the examples and comparative examples were produced by the following method. [Production Example C1] 100 parts by mass of NF180 was dispersed in 300 parts by mass of ethanol, 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 distilled off under reduced pressure, and further dried at 90 °C for 3 hours for surface treatment to obtain an inorganic filler (SC1) having an inorganic filler surface-treated with a surface treatment agent.

[0154] [Production 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 part 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 distilled off under reduced pressure, and further dried at 90 °C for 3 hours for surface treatment to obtain an inorganic filler (SC2) having an inorganic filler surface-treated with a surface treatment agent.

[0155] [Production 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, 4 parts by mass of γ-MPS was added, and the mixture was heated to reflux for 2 hours. The solvent was distilled off under reduced pressure, and further dried at 90 °C for 3 hours for surface treatment to obtain an inorganic filler (SC3) having an inorganic filler surface-treated with a surface treatment agent.

[0156] The compositions of the inorganic fillers (SC1 to SC3) having an inorganic filler surface-treated with a surface treatment agent are shown in Table 3 below.

[0157] [Table 3]

[0158] The physical properties of the curable compositions for dental restoration and the cured products obtained using the curable compositions for dental restoration in Examples and Comparative Examples were evaluated by the following property evaluation tests. (Test 1) Flexural strength, fracture toughness (three-point bending test) Regarding the dental composite resin, after subjecting the curable compositions for dental restoration of each of the manufactured examples and comparative examples to vacuum degassing, they were filled into a stainless steel mold (dimensions: thickness 2 mm × width 2 mm × length 25 mm), the top and bottom were pressed against each other with slide glasses, and a dental visible light irradiator (Pen Curer 2000, manufactured by Morita Corporation) was used to irradiate each point for 10 seconds, 5 points on each side, and both sides were irradiated with light to cure. For each of the examples and comparative examples, 5 specimens of the cured product were prepared as samples. The specimens of the cured product were taken out of the mold, immersed in water at 37°C for 7 days, and then using a universal testing machine (manufactured by Shimadzu Corporation, product code "AG-I 100kN"), under the conditions of a distance between supports of 20 mm and a crosshead speed of 1 mm / min, the flexural strength and fracture toughness of the specimens of the cured product were measured, and the average value of the measured values of the 5 specimens was calculated and taken as the flexural strength and fracture toughness of the dental composite resin. Regarding the dental mill blank, from each of the manufactured examples and comparative examples of the dental mill blank, using a diamond cutter, test pieces (dimensions: thickness 1.2 mm × width 4 mm × length 14 mm) were prepared, and polished with #2000 abrasive paper to prepare samples. Regarding the point that the distance between supports when using a universal testing machine was set to 12 mm, and the point that 10 specimens of the cured product were prepared as samples, except for these points, the measurement was carried out in the same manner as the measurement of the specimens of the dental composite resin described above, the average value of the measured values of the 10 specimens was calculated, and taken as the flexural strength and fracture toughness of the dental mill blank. Regarding the flexural strength as a dental composite resin, it was judged that 150 MPa or more was good, and 180 MPa or more was judged to be even better. Also, regarding the fracture toughness of the dental composite resin, it was judged that 15 mJ or more was good, and 20 mJ or more was judged to be even better. Regarding the flexural strength as a dental mill blank, it was judged that 240 MPa or more was good, and 280 MPa or more was judged to be even better. Also, regarding the fracture toughness of the dental mill blank, it was judged that 30 mJ or more was good, and 35 mJ or more was judged to be even better.

[0159] (Test 2) Gloss retention rate Regarding the dental composite resin, after subjecting the curable compositions for dental restoration of each of the manufactured examples and comparative examples to vacuum degassing, they were filled into a stainless steel mold (dimensions: thickness 2 mm × width 10 mm × length 10 mm), the top and bottom were pressed and contacted with slide glasses, and a dental visible light irradiator (Pentacure 2000, manufactured by Morita Corporation) was used to irradiate each point for 10 seconds, 5 points at a time on one side, and both sides were irradiated with light to cure. The obtained cured products were polished in the order of #1000 abrasive paper, #2000 abrasive paper, and #3000 abrasive paper under dry conditions, and finally polished with a lapping film. Regarding the test pieces after polishing, the glossiness before and after the toothbrush abrasion test (toothbrush: "Vetion (registered trademark) Lion" (hardness: normal; manufactured by Lion Corporation), toothpaste: "Dentaclear MAX (registered trademark)" (manufactured by Lion Corporation), load: 250 g, test solution: distilled water / toothpaste = 90 / 10 (volume / volume, 50 mL), number of abrasion cycles: 40,000 times) was determined by a gloss meter ("VG-2000", manufactured by Nippon Denshoku Industries Co., Ltd.). Note that the 60-degree specular gloss (Gs(60°)) was measured as the glossiness. The glossiness retention rate (%) was calculated by dividing the glossiness after the obtained toothbrush abrasion test by the glossiness before the test. Regarding the dental mill blank, except that test pieces (dimensions: thickness 2 mm × width 10 mm × length 10 mm) were prepared from each of the manufactured examples and comparative examples of the dental mill blank using a diamond cutter, the measurement was carried out in the same manner as the measurement of the sample of the dental composite resin described above. The glossiness retention rate as the dental composite resin and the dental mill blank is preferably 80% or more, more preferably 90% or more, and even more preferably 93% or more.

[0160] (Test 3) Paste operability (adhesion force) After subjecting the dental restorative curable compositions of each of the manufactured examples and comparative examples to vacuum defoaming, they were filled into syringes and allowed to stand at 25°C for 24 hours, and these were used as samples for the adhesion test. The paste was extruded from the syringe and filled into a cup having a capacity of bottom surface Φ11 mm × top surface Φ13 mm × height 8 mm. A jig having a stainless steel cylinder with a tip of Φ10 mm × 5 mm was attached to a small bench-top testing machine (manufactured by Shimadzu Corporation, "EZ Test"), and after lightly contacting the bottom surface of the stainless steel cylinder attached to the cylindrical jig with the surface of the filled paste, the maximum stress when pulled up at a crosshead speed of 50 mm / min was taken as the adhesion to the stainless steel plate at 25°C (n = 2). As an evaluation of the workability of the paste, an adhesion of 1.5 N or less is preferable, and 1.0 N or less is more preferable. On the other hand, when the adhesion is 2.0 N or more, it is judged that the workability of the paste when filling with a dental instrument is low.

[0161] (Test 4) Cracking rate of the cured product Regarding the cured products of the dental restorative curable compositions according to each of the manufactured examples and comparative examples, the presence or absence of cracks in the interior and appearance of the cured products was evaluated using a tabletop microfocus X-ray CT system (manufactured by Shimadzu Corporation, "inspeXio (registered trademark) SMX-90CT") (n = 10). As an evaluation of the cracking rate of the cured product, it is preferable that the number of cured products with cracks is 1 or less, and most preferably 0. On the other hand, if it is 3 or more, it is judged that the quality is poor from the viewpoints such as a decrease in mechanical strength and a deterioration in appearance.

[0162] The dental restorative curable compositions according to the examples and comparative examples and the cured products of the dental restorative curable compositions were manufactured by the following method.

[0163] [Examples 1 to 14, Comparative Examples 1 to 4 (dental composite resin)] Using the polymerizable monomer-containing compositions (EM1 to 13) obtained in the above Production Examples and the inorganic fillers (SC1 to 2), they were mixed and kneaded at 40 °C under yellow light at the composition ratios shown in Tables 4 and 5 below to make them uniform, then vacuum degassed, and paste-like curable compositions for dental restoration of Examples 1 to 14 and Comparative Examples 1 to 4 were prepared. The above characteristic evaluation tests (Tests 1 to 3) were carried out on the prepared curable compositions for dental restoration. The results are shown in Tables 4 and 5 below.

[0164]

Table 4

[0165]

Table 5

[0166] As shown in Tables 4 and 5, the paste workabilities of the curable compositions for dental restoration obtained in Examples 1 to 14 were all good. Also, it was found that the cured products of the curable compositions for dental restoration had high flexural strength and fracture toughness even after immersion in water at 37 °C assuming the oral cavity. Furthermore, it was found that the cured products were also excellent in gloss retention rate. On the other hand, the paste workability of the curable composition for dental restoration obtained in Comparative Example 1 was good, and the cured product of the curable composition for dental restoration had high flexural strength, but the fracture toughness and gloss retention rate were low. Also, the paste workability of the curable composition for dental restoration obtained in Comparative Example 2 was poor, and the cured product of the curable composition for dental restoration had high flexural strength, but the fracture toughness and gloss retention rate were low. Also, the paste workability of the curable composition for dental restoration obtained in Comparative Example 3 was good, but the flexural strength, fracture toughness, and gloss retention rate were very poor. The curable compositions for dental restoration obtained in Comparative Examples 1 to 3 do not contain component (B), and thus are considered to be inferior in the above characteristics. In addition, since the dental restorative curable composition obtained in Comparative Example 4 did not contain an inorganic filler, it did not become paste-like, and the paste workability could not be evaluated. Also, the flexural strength, fracture toughness, and gloss retention rate of the cured product of the dental restorative curable composition obtained in Comparative Example 4 were very poor.

[0167] [Examples 15 to 17, Comparative Example 5 (dental mill blank)] Using the polymerizable monomer-containing compositions (EM14 to 15 and CM4) and inorganic fillers (SC1 to 2) obtained in the above Production Examples, the compositions were mixed and kneaded at 40 °C under yellow light at the composition ratios shown in Table 6 below to make them uniform, then vacuum degassed, and paste-like dental restorative curable compositions of Examples 15 to 17 and Comparative Example 5 were prepared. Next, the dental restorative curable composition was poured into a rectangular resin container with a length of 15 mm × width of 15 mm × depth of 20 mm, fixed in the chamber of an autoclave device (manufactured by Kyou Shin Engineering Co., Ltd.), the inside of the chamber was replaced with nitrogen with a purity of 99.99% 12 times at 0.15 MPa, then pressurized to 0.5 MPa with nitrogen of the same purity, and simultaneously with the completion of the pressurization, the temperature inside the chamber was raised to 130 °C and held for 60 minutes for polymerization curing, and finally the cured product was taken out of the container. The above characteristic evaluation tests (Tests 1, 2, and 4) were carried out on the obtained cured product. The results are shown in Table 6 below.

[0168] [Comparative Example 6 (dental mill blank)] Using the polymerizable monomer-containing composition (CM5) obtained in the above Production Example and the inorganic filler (SC1), they were mixed and kneaded at 40 °C under yellow light at the composition ratios shown in Table 6 below until uniform, then vacuum degassed to prepare a paste-like curable composition for dental restoration of Comparative Example 6. Next, the curable composition for dental restoration was poured into a rectangular resin container measuring 15 mm in length × 15 mm in width × 20 mm in depth, fixed in the chamber of an autoclave device (manufactured by Kyo Shin Engineering Co., Ltd.), replaced with nitrogen having a concentration of 99.99% 12 times at 0.15 MPa, then pressurized to 0.5 MPa with nitrogen of the same purity, and simultaneously with the completion of the pressurization, the temperature inside the chamber was raised to 80 °C and held for 60 minutes for polymerization and curing, and finally the cured product was taken out from the container. The above characteristic evaluation tests (Tests 1, 2, and 4) were carried out on the obtained cured product. The results are shown in Table 6 below.

[0169] [Comparative Example 7 (Dental Mill Blank)] (1) 200 g of the inorganic filler (SC3) obtained in the above Production Example was spread on the lower punch bar of a press mold having a circular hole with a diameter of 200 mm. The powder was leveled by tapping, the upper punch bar was set on top, and uniaxial pressing (pressing pressure: 300 kN (26.5 MPa), pressing time: 5 minutes) was carried out using a table press machine. The upper and lower punch bars were removed from the mold, and a molded body in which the inorganic filler (SC3) had aggregated was taken out. The molded body obtained by the above uniaxial pressing was further subjected to press molding by CIP (pressure: 350 MPa, pressurization time: 20 minutes) to obtain an inorganic filler molded body. (2) The obtained inorganic filler molded body was immersed in the polymerizable monomer-containing composition (CM5), degassed under reduced pressure (10 hPa), and left standing 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). Then, it was heated at 70 °C for 24 hours using a hot air dryer, and then heated at 110 °C for 5 hours to obtain a cured product as a dental mill blank. The above characteristic evaluation tests (Tests 1, 2, and 4) were carried out on the obtained cured product. The results are shown in Table 6 below.

[0170]

Table 6

[0171] All of the cured products of the dental restorative curable compositions obtained in Examples 15 to 17 had no cracks. Further, it was found that they had high flexural strength and fracture toughness even after immersion in water at 37°C assuming the oral cavity. Furthermore, it was found that the cured products were also excellent in gloss retention rate. On the other hand, the cured product of the dental restorative curable composition obtained in Comparative Example 5 had a large amount of cracks, and accordingly, the flexural strength, fracture toughness, and gloss retention rate were significantly low. Regarding the cured product of the dental restorative curable composition obtained in Comparative Example 6, the gloss retention rate was not poor, but cracks were confirmed and the flexural strength and fracture toughness were low. Regarding the cured product of the dental restorative curable composition obtained in Comparative Example 7, the flexural strength and fracture toughness were low, a few cracks occurred, and the gloss retention rate was low. The dental restorative curable compositions obtained in Comparative Examples 5 to 7 do not contain component (B), and thus it is considered that the properties of the obtained cured products are inferior.

[0172] From the above results, it was found that the cured product obtained from the dental restorative curable composition which is one aspect of the present invention has high flexural strength and fracture toughness and is excellent in gloss retention rate. Furthermore, it was also found that the cured product obtained from the dental restorative curable composition had no cracks and had a good appearance. Also, it was found that the dental restorative curable composition was excellent in paste workability.

Industrial Applicability

[0173] The cured product obtained from the curable composition for dental restoration, which is one aspect of the present invention, is excellent in flexural strength, fracture toughness, and gloss retention rate. That is, it has sufficient mechanical strength to be replaceable with natural teeth and is suitably used as a material for repairing tooth defects and dental caries, particularly as a dental composite resin. Further, the cured product is suitably used as a dental mill blank. Furthermore, the cured product obtained from the curable composition for dental restoration, which is one aspect of the present invention, has no cracks and has a good appearance. In addition, the curable composition for dental restoration, which is one aspect of the present invention, is excellent in terms of handling because of its excellent paste operability.

Claims

Claim 1 A curable composition for dental restoration, containing a (meth)acrylic acid ester compound (A) having two or more (meth)acryloyloxy groups in one molecule, an aromatic vinyl compound (B), an inorganic filler (C), and a polymerization initiator (D). The aromatic vinyl compound (B) is represented by the following formula (I). 【Chemical 1】 [In formula (I), X represents a substituted or unsubstituted aromatic hydrocarbon ring or a substituted or unsubstituted aromatic heterocyclic ring.] The substituted aromatic hydrocarbon ring represented by X and the substituted aromatic heterocyclic ring each independently may have one or more substituents R １ and may have one or more substituents R Substituent R １ represents a halogen atom, a substituted or unsubstituted alkyl group having 1 to 20 carbon atoms, a substituted or unsubstituted alicyclic hydrocarbon group having 3 to 20 ring-forming atoms, a substituted or unsubstituted aromatic hydrocarbon group having 6 to 20 ring-forming atoms, a substituted or unsubstituted heterocyclic group having 3 to 20 ring-forming atoms, *-OR ２ group represented by, *-NR ３ R ４ group represented by, *-C(=O)OR ５ group represented by, *-O(C=O)R ６ group represented by, *-SO ３ R ７ group represented by, *-PR ８ R ９ , *-B(OH) ２ group represented by, a substituted or unsubstituted silyl group, a nitro group, or a cyano group. R ２ 、R ３ 、R ４ 、R ５ 、R ６ 、R ７ 、R ８ and R ９ each independently represents a hydrogen atom, a substituted or unsubstituted alkyl group having 1 to 10 carbon atoms, a substituted or unsubstituted alicyclic hydrocarbon group having 3 to 20 ring-forming atoms, or a substituted or unsubstituted aromatic hydrocarbon group having 6 to 20 ring-forming atoms. The *-B(OH) ２ Each hydroxy group in the group represented by may be substituted with a protecting group that is converted to a hydroxy group by deprotection. * each independently represents a ring-forming atom forming the aromatic hydrocarbon ring represented by X or the bonding position with a ring-forming atom forming the aromatic heterocyclic ring.] The aromatic hydrocarbon ring or aromatic heterocyclic ring represented by X has substituents R １ When there are two or more of them, the two or more substituents R １ may be the same as each other or may be different from each other. The aromatic hydrocarbon ring or aromatic heterocyclic ring represented by X has two or more substituents R １ and when at least two of the two or more existing substituents R １ selected from are substituted on adjacent ring-forming atoms, the two adjacent substituents R １ may be bonded to each other to form a ring structure consisting only of carbon atoms and not containing an unsaturated bond, may form a ring structure containing carbon atoms and heteroatoms and not containing an unsaturated bond, or may not be bonded to each other and not form a ring structure. ] Claim 2 The curable composition for dental restoration according to claim 1, wherein the content of the aromatic vinyl compound (B) is 2 to 60% by mass in a total of 100% by mass of components (A) and (B). Claim 3 In the formula (I), X is an aromatic hydrocarbon ring having one substituent R １ or an unsubstituted aromatic hydrocarbon ring, or an aromatic heterocyclic ring having one substituent R １ The curable composition for dental restoration according to claim 1 or 2, which is an unsubstituted aromatic heterocyclic ring. Claim 4 In the formula (I), when X represents a substituted aromatic hydrocarbon ring or a substituted aromatic heterocyclic ring, the substituent R １ in at least one or all of them is a substituent having an electron-donating property among the substituents represented by the substituent R １ The curable composition for dental restoration according to claim 1 or 2. Claim 5 The substituent having electron-donating property is a substituted or unsubstituted alkyl group having 1 to 20 carbon atoms, *-OR ２ a group represented by, or *-NR ３ R ４ a group represented by, and the curable composition for dental restoration according to claim 4. Claim 6 The curable composition for dental restoration according to claim 1 or 2, wherein the number of ring-forming atoms forming the aromatic hydrocarbon ring in the substituted or unsubstituted aromatic hydrocarbon ring represented by X in formula (I) is 6 to 25. Claim 7 The curable composition for dental restoration according to claim 1 or 2, wherein the number of ring-forming atoms forming the aromatic heterocyclic ring in the substituted or unsubstituted aromatic heterocyclic ring represented by X in formula (I) is 5 to 20. Claim 8 In the formula (I), X is one selected from the group consisting of a substituted or unsubstituted benzene ring, a substituted or unsubstituted naphthalene ring, a substituted or unsubstituted anthracene ring, a substituted or unsubstituted fluorene ring, a substituted or unsubstituted phenanthrene ring, a substituted or unsubstituted pyrene ring, a substituted or unsubstituted furan ring, a substituted or unsubstituted thiophene ring, a substituted or unsubstituted pyrrole ring, a substituted or unsubstituted imidazole ring, a substituted or unsubstituted oxazole ring, a substituted or unsubstituted pyridine ring, a substituted or unsubstituted pyrazine ring, a substituted or unsubstituted pyrimidine ring, a substituted or unsubstituted pyridazine ring, a substituted or unsubstituted triazine ring, a substituted or unsubstituted benzofuran ring, a substituted or unsubstituted benzothiophene ring, a substituted or unsubstituted quinoline ring, a substituted or unsubstituted isoquinoline ring, a substituted or unsubstituted quinazoline ring, a substituted or unsubstituted indole ring, a substituted or unsubstituted carbazole ring, a substituted or unsubstituted dibenzofuran ring, and a substituted or unsubstituted dibenzothiophene ring. The curable composition for dental restoration according to claim 1 or 2.

9. In the formula (I), X is a substituted or unsubstituted benzene ring. The curable composition for dental restoration according to claim 8.

10. The average primary particle diameter of the inorganic filler (C) is 0.01 to 5 μm. The curable composition for dental restoration according to claim 1 or 2.

11. The content of the inorganic filler (C) is 50 to 95% by mass based on the total amount of the curable composition for dental restoration. The curable composition for dental restoration according to claim 1 or 2.

12. The polymerization initiator (D) contains a photo-polymerization initiator. The curable composition for dental restoration according to claim 1 or 2.

13. The polymerization initiator (D) contains a heat-polymerization initiator. The curable composition for dental restoration according to claim 1 or 2.

14. It is for dental composite resin. The curable composition for dental restoration according to claim 1 or 2.

15. It is for dental mill blank. The curable composition for dental restoration according to claim 1 or 2.

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