Dental composition

Abstract

The present invention provides a dental composition which has excellent stability to ambient light under a high illuminance and has excellent photocurability. The present invention relates to a dental composition comprising an ultraviolet absorber (A), a polymerizable monomer (B), and a photopolymerization initiator (C), wherein the ultraviolet absorber (A) is a compound satisfying the following [I], [II], and [III]: [I] the compound has a triazine skeleton; [II] the compound dissolves in an amount of 0.12 parts by mass or more in 100 parts by mass of 2-hydroxyethyl methacrylate; and [III] when the ultraviolet absorber (A) is dissolved in ethyl acetate as a solvent to prepare a solution having a concentration of 3×10-5 mol / L and the solution is examined for maximum absorption wavelength with a spectrophotometer using a quartz cell having an optical path length of 10 mm and when the measurement is made over the wavelength range of 250-500 nm using a compound having an absorbance of 0.5 or greater, then the solution has a maximum absorption wavelength in the wavelength range of 310-400 nm.

Description

Dental composition

[0001] The present invention relates to a dental composition, and more particularly to a dental composition that has excellent ambient light stability under high illuminance and excellent photocurability.

[0002] To repair tooth structures (enamel, dentin, and cementum) damaged by caries or the like, filling and restorative materials such as filling composite resins and filling compomers, and crown and crown restorative materials such as metal alloys, porcelain materials, and resin materials are usually used. Generally, filling and restorative materials and crown and crown restorative materials (both of which may be collectively referred to as "dental restorative materials" in this specification) do not themselves have adhesive properties to tooth structures. Therefore, various adhesive systems using adhesives have conventionally been used to bond dental restorative materials to tooth structures.

[0003] Conventionally, widely used adhesive systems include the so-called acid etching (total etching) adhesive system, in which the surface of the tooth is etched using an acid etching agent such as an aqueous solution of phosphoric acid, and then a bonding agent is applied to bond the tooth and dental restorative material.

[0004] On the other hand, there is a so-called self-etching adhesive system that does not use an acid etching agent. Conventionally, this type of adhesive system has mainly been a two-step adhesive system in which a self-etching primer containing an acidic monomer, a hydrophilic monomer, and water is applied to the surface of the tooth, and then a bonding agent containing a cross-linking monomer and a polymerization initiator is applied without rinsing with water. However, recently, a one-step adhesive system using a one-component dental adhesive (one-component dental bonding material) that combines the functions of both a self-etching primer and a bonding agent has become widely used.

[0005] In the adhesive systems described above, a dental bonding material is typically applied to the area to be restored and then light-cured, so a photopolymerization initiator is used in such adhesive systems.

[0006] Dental bonding materials are applied to cavities after caries removal and then light-cured using a light irradiator. Naturally, it is desirable for the bonding material layer to be sufficiently cured by light irradiation. Meanwhile, in clinical settings, it is desirable for the bonding material not to be cured by environmental light, such as fluorescent lights or dental lamps, in dental clinics from the time the bonding material is collected until it is applied to the cavity.

[0007] From this viewpoint, dental compositions according to Patent Documents 1 to 4 have been proposed.

[0008] JP 2016-166138 A JP 2006-11754 A JP 2018-104367 A JP 2004-231913 A

[0009] In recent years, particularly in the context of the increasing illuminance of "operating lights" used to illuminate the dentist's hands and the oral cavity, dental bonding materials have been sought that can achieve, at a higher level, the contradictory properties of being difficult to cure, i.e., having excellent ambient light stability under high illuminance, and curing when irradiated with light from a light irradiator, i.e., having excellent photocurability. However, the dental compositions disclosed in Patent Documents 1 to 4 have room for improvement in terms of achieving both environmental light stability under high illuminance and photocurability.

[0010] An object of the present invention is to provide a dental composition that has excellent stability to environmental light under high illuminance and excellent photocurability.

[0011] As a result of intensive research to solve the above-mentioned problems, the present inventors have found that the above-mentioned problems can be solved by including an ultraviolet absorber that has a triazine skeleton, is soluble in an amount of 0.12 part by mass or more in 100 parts by mass of 2-hydroxyethyl methacrylate, and has a maximum absorption wavelength in the wavelength region of 310 nm or more and 400 nm or less. Based on this finding, the present inventors have conducted further research and have completed the present invention.

[0012] That is, the present invention encompasses the following inventions: [1] A composition comprising an ultraviolet absorber (A), a polymerizable monomer (B), and a photopolymerization initiator (C), wherein the ultraviolet absorber (A) has the following [I], [II], and [III]: [I] has a triazine skeleton; [II] is soluble in 0.12 parts by mass or more relative to 100 parts by mass of 2-hydroxyethyl methacrylate; and [III] is prepared by dissolving the ultraviolet absorber (A) in ethyl acetate as a solvent to a concentration of 3×10 -5 [2] The dental composition according to [1], wherein the ultraviolet absorber (A) is a triazine-based ultraviolet absorber represented by the following general formula (1): (R 1 represents an alkyl group or an alkoxy group, and R 2 and R 3 are the same or different and each represents a hydrogen atom, a hydroxy group, an alkyl group, an alkoxy group, or a halogen atom; R 4 , R 5 , and R 6 are the same or different and represent a hydrogen atom or an alkyl group; R 7 , and R 8 are the same or different and each represents a hydrogen atom, a hydroxy group, an alkyl group, an alkoxy group, an aryl group, or a halogen atom; R 1 ~R 8 The alkyl group and alkoxy group of the formula (I) may have a substituent.) [3] The dental composition according to the above [1] or [2], wherein the content of the ultraviolet absorber (A) is 85 parts by mass or more in 100 parts by mass of the total of the ultraviolet absorbers. [4] The content of the ultraviolet absorber (A) is 85 parts by mass or more in 100 parts by mass of the total of the ultraviolet absorbers. 1 [5] The dental composition according to [2] or [3], wherein R of the ultraviolet absorber (A) is an alkyl group or an alkoxy group having 1 to 15 carbon atoms. 1 [6] The dental composition according to [4], wherein R of the ultraviolet absorber (A) is a branched alkyl group or an alkoxy group having 3 to 15 carbon atoms. 1is a 2-ethylhexyloxy group. [7] The dental composition according to any one of [1] to [6], wherein the ultraviolet absorber (A) is bisethylhexyloxyphenol methoxyphenyl triazine and / or 2-[4,6-bis(biphenyl-4-yl)-1,3,5-triazin-2-yl]-5-[(2-ethylhexyl)oxy]phenol. [8] The dental composition according to any one of [1] to [7], wherein the content of the ultraviolet absorber (A) is 0.01 parts by mass or more and 1 part by mass or less per 100 parts by mass of the total of the polymerizable monomers (B) contained in the dental composition. [9] The dental composition according to any one of [1] to [8], wherein the mass ratio (A):(C) of the content of the ultraviolet absorber (A) to the content of the photopolymerization initiator (C) is 1:0.1 to 1:50.

[10] The dental composition according to any one of [1] to [9], wherein the photopolymerization initiator (C) is an α-diketone and / or a (bis)acylphosphine oxide.

[11] The dental composition according to

[10] , wherein the content of the photopolymerization initiator (C) is 0.01 parts by mass or more and 5 parts by mass or less per 100 parts by mass of the dental composition.

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

[10] , wherein the dental composition is a one-component type.

[0013] According to the present invention, a dental composition having excellent stability to ambient light under high illuminance and excellent photocurability can be provided.

[0014] The dental composition of the present invention comprises an ultraviolet absorber (A), a polymerizable monomer (B), and a photopolymerization initiator (C), and the ultraviolet absorber (A) is the following [I], [II], and [III]: [I] has a triazine skeleton; [II] is soluble in 100 parts by mass of 2-hydroxyethyl methacrylate in an amount of 0.12 parts by mass or more; and [III] is dissolved in ethyl acetate as a solvent to a concentration of 3×10 -5 A 100 mol / L solution is prepared, and when the wavelength range of 250 nm to 500 nm is measured using a spectrophotometer in a quartz cell with an optical path length of 10 mm, the compound has a maximum absorption wavelength in the wavelength range of 310 nm or more and 400 nm or less.

[0015] In this specification, the term "(meth)acrylic" is a general term for methacrylic and acrylic. In this specification, the upper and lower limits of the numerical ranges (contents of each component, values ​​calculated from each component, physical properties, etc.) can be combined as appropriate.

[0016] [Ultraviolet Absorber (A)] The ultraviolet absorber (A) used in the dental composition of the present invention is a triazine-based ultraviolet absorber having a maximum absorption wavelength in the wavelength range of 310 nm to 400 nm. The method for measuring the maximum absorption wavelength is as described in the Examples below.

[0017] In addition to the fact that triazine-based ultraviolet absorbers have higher absorption capabilities in the ultraviolet region than ultraviolet absorbers of other compounds, triazine-based ultraviolet absorbers having a maximum absorption wavelength in the wavelength region of 310 nm or more and 400 nm or less are presumed to exhibit superior stability under high-intensity environmental light such as operating lights, and to exhibit excellent photocurability without inhibiting irradiation for curing with a blue LED light irradiator. Furthermore, by selecting an ultraviolet absorber (A) according to the present invention that has particularly excellent solubility in monomers, the ultraviolet absorber is dispersed and present in the dental composition, thereby ensuring the ultraviolet absorption effect in just the right amount and presumed to exhibit particularly excellent stability under high-intensity environmental light.

[0018] The ultraviolet absorber (A) is preferably a triazine ultraviolet absorber represented by the following general formula (1), because it has excellent environmental light stability and photocurability under high illuminance. (R 1 represents an alkyl group or an alkoxy group, and R 2 , and R 3 are the same or different and each represents a hydrogen atom, a hydroxy group, an alkyl group, an alkoxy group, or a halogen atom; R 4 , R 5 , and R 6 are the same or different and represent a hydrogen atom or an alkyl group; R 7 , and R 8are the same or different and each represents a hydrogen atom, a hydroxy group, an alkyl group, an alkoxy group, an aryl group, or a halogen atom; R 1 ~R 8 The alkyl group and alkoxy group may have a substituent.

[0019] R 1 ~R 8 The alkyl group represented by may be any of linear, branched, and cyclic. 1 ~R 8 The alkyl group represented by the formula (I) is preferably branched. Examples of the alkyl group include a methyl group, an ethyl group, an n-propyl group, an isopropyl group, a cyclopropyl group, an n-butyl group, an isobutyl group, a sec-butyl group, a tert-butyl group, a cyclobutyl group, an n-pentyl group, an isopentyl group, a neopentyl group, a tert-pentyl group, a cyclopentyl group, an n-hexyl group, an isohexyl group, a cyclohexyl group, an n-heptyl group, a cycloheptanyl group, an n-octyl group, a 2-ethylhexyl group, a cyclooctyl group, an n-nonyl group, a cyclononyl group, and an n-decyl group. The number of carbon atoms in the alkyl group is preferably 1 to 15, more preferably 1 to 12, even more preferably 1 to 10, and particularly preferably 1 to 8. The branched and cyclic alkyl groups preferably have 3 to 15 carbon atoms, more preferably 3 to 12 carbon atoms, even more preferably 3 to 10 carbon atoms, and particularly preferably 3 to 8 carbon atoms.

[0020] R 1 With regard to (a), in terms of superior environmental light stability and photocurability under high illuminance, it is preferably an alkyl group or alkoxy group having 1 to 15 carbon atoms, more preferably a branched alkyl group or alkoxy group having 3 to 15 carbon atoms, and even more preferably a 2-ethylhexyloxy group.

[0021] R 1 ~R 3 , and R 7 ~R 8 The alkoxy group represented by the formula (I) may be linear, branched, or cyclic. 1 ~R3 , and R 7 ~R 8 The alkoxy group represented by the formula (I) is preferably branched. Examples of the alkoxy group include a methoxy group, an ethoxy group, an n-propoxy group, an isopropoxy group, an n-butoxy group, a tert-butoxy group, an n-hexyloxy group, a cyclohexyloxy group, an n-octyloxy group, and a 2-ethylhexyloxy group. The number of carbon atoms in the alkoxy group is preferably 1 to 15, more preferably 1 to 12, even more preferably 1 to 10, and particularly preferably 1 to 8. The number of carbon atoms in the branched and cyclic alkoxy groups is preferably 3 to 15, more preferably 3 to 12, even more preferably 3 to 10, and particularly preferably 3 to 8.

[0022] R 7 , and R 8 Examples of the aryl group represented by the formula (I) include a phenyl group, a naphthyl group, an anthryl group, etc. The number of carbon atoms in the aryl group is preferably 6 to 14, and more preferably 6 to 10.

[0023] R 2 ~R 3 , and R 7 ~R 8 Examples of the halogen atom represented by the formula (I) include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom.

[0024] R 1 ~R 8 The alkyl group and alkoxy group in R may have a substituent. Examples of the substituent include a halogen atom (fluorine atom, chlorine atom, bromine atom, iodine atom), a hydroxy group, an alkoxy group having 1 to 6 carbon atoms, a dialkylamino group having an alkyl group having 1 to 6 carbon atoms, an amino group, etc. 1 ~R 8 The alkyl group and alkoxy group may be unsubstituted.

[0025] As the ultraviolet absorber (A), from the viewpoints of environmental light stability under high illuminance and photocurability, it is preferable to use a triazine-based ultraviolet absorber represented by the above general formula (1) which has a maximum absorption wavelength in the wavelength range of 310 nm or more and 400 nm or less when measured in the wavelength range of 250 nm to 500 nm.

[0026] Furthermore, the range of the wavelength band in which the ultraviolet absorber (A) has the maximum absorption wavelength is preferably 390 nm or less, more preferably 385 nm or less, even more preferably 380 nm or less, and particularly preferably 375 nm or less, from the viewpoints of exhibiting better stability against environmental light under high illuminance such as operating light and exhibiting better photocurability.

[0027] Furthermore, the ultraviolet absorber (A) dissolves in an amount of 0.12 parts by mass or more per 100 parts by mass of 2-hydroxyethyl methacrylate. By using an ultraviolet absorber with high solubility in monomers, the ultraviolet absorber is dispersed and present in the dental composition, ensuring that the ultraviolet absorption effect is adequate and is presumed to exhibit particularly excellent stability against environmental light under high illuminance. From this perspective, the ultraviolet absorber (A) is preferably soluble in an amount of 0.14 parts by mass or more, more preferably soluble in an amount of 0.20 parts by mass or more, per 100 parts by mass of 2-hydroxyethyl methacrylate. The amount of solubility per 100 parts by mass of 2-hydroxyethyl methacrylate is an index for selecting an ultraviolet absorber (A) with high solubility in monomers. However, as shown in the examples described below (e.g., Examples 1-8 and 2-8), the dental composition of the present invention does not necessarily contain 2-hydroxyethyl methacrylate.

[0028] Specific examples of the ultraviolet absorber (A) include 2,4,6-tris(2,4-dihydroxyphenyl)-1,3,5-triazine, bisethylhexyloxyphenol methoxyphenyl triazine, 2-[4,6-bis(biphenyl-4-yl)-1,3,5-triazin-2-yl]-5-[(2-ethylhexyl)oxy]phenol, and the like, with bisethylhexyloxyphenol methoxyphenyl triazine and / or 2-[4,6-bis(biphenyl-4-yl)-1,3,5-triazin-2-yl]-5-[(2-ethylhexyl)oxy]phenol being preferred. One type of ultraviolet absorber (A) may be used alone, or two or more types may be used in combination.

[0029] The content of the ultraviolet absorber (A) is preferably 85 parts by mass or more, more preferably 90 parts by mass or more, even more preferably 95 parts by mass or more, even more preferably 98 parts by mass or more, and particularly preferably 100 parts by mass, based on 100 parts by mass of the total ultraviolet absorbers contained in the dental composition of the present invention, in view of the structural characteristics of the triazine ultraviolet absorber (A) (such as steric hindrance due to the phenyl group) and the fact that the triazine ultraviolet absorber (A) compound itself has a maximum absorption wavelength in the wavelength band of 310 nm or more and 400 nm or less, thereby exhibiting superior stability against environmental light under high illuminance and exhibiting superior photocurability.

[0030] From the viewpoints of environmental light stability and photocurability under high illuminance, the content of the ultraviolet absorber (A) is preferably 0.0001% by mass or more, more preferably 0.001% by mass or more, even more preferably 0.005% by mass or more, and particularly preferably 0.01% by mass or more, relative to the total mass (100% by mass) of the dental composition of the present invention. Furthermore, from the viewpoints of environmental light stability and photocurability under high illuminance, the content of the ultraviolet absorber (A) is preferably 1.5% by mass or less, more preferably 1.2% by mass or less, even more preferably 0.8% by mass or less, and particularly preferably 0.4% by mass or less, relative to the total mass (100% by mass) of the dental composition of the present invention.

[0031] From the viewpoints of environmental light stability and photocurability under high illuminance, the content of the ultraviolet absorber (A) is preferably 0.001 parts by mass or more, more preferably 0.01 parts by mass or more, even more preferably 0.05 parts by mass or more, and particularly preferably 0.1 parts by mass or more, relative to 100 parts by mass of the total of the polymerizable monomers (B). From the viewpoints of environmental light stability and photocurability under high illuminance, the content of the ultraviolet absorber (A) is preferably 5 parts by mass or less, more preferably 1 part by mass or less, even more preferably 0.8 parts by mass or less, and particularly preferably 0.5 parts by mass or less, relative to 100 parts by mass of the total of the polymerizable monomers (B).

[0032] [Polymerizable Monomer (B)] A radically polymerizable monomer is preferably used as the polymerizable monomer (B) used in the dental composition of the present invention. Examples of the radically polymerizable monomer in the polymerizable monomer (B) include (meth)acrylate-based polymerizable monomers, (meth)acrylamide-based polymerizable monomers, esters of α-cyanoacrylic acid, (meth)acrylic acid, α-halogenated acrylic acid, crotonic acid, cinnamic acid, sorbic acid, maleic acid, itaconic acid, etc., vinyl esters, vinyl ethers, mono-N-vinyl derivatives, and styrene derivatives. Among these, (meth)acrylate-based polymerizable monomers and (meth)acrylamide-based polymerizable monomers are preferred from the viewpoint of curability.

[0033] The polymerizable monomer (B) is roughly classified into a polymerizable monomer (B-1) having an acidic group and a polymerizable monomer (B-2) not having an acidic group. The polymerizable monomer (B) may be used alone or in combination of two or more kinds.

[0034] <Polymerizable Monomer (B-1) Having an Acidic Group> The dental composition of the present invention may contain a polymerizable monomer (B-1) having an acidic group. The polymerizable monomer (B-1) having an acidic group used in the present invention is preferably a radically polymerizable monomer having at least one acidic group and a polymerizable group. From the viewpoint of adhesiveness, the acidic group is preferably a phosphate group, a pyrophosphate group, a thiophosphate group, a phosphonate group, a carboxylic acid group, a sulfonic acid group, or the like. Furthermore, from the viewpoints of photocurability and ease of radical polymerization, the polymerizable group is preferably a (meth)acryloyloxy group and / or a (meth)acrylamide group. The polymerizable monomer (B-1) having an acidic group may be blended alone or in combination of two or more types.

[0035] Examples of the polymerizable monomer having a phosphoric acid group include 2-(meth)acryloyloxyethyl dihydrogen phosphate, 3-(meth)acryloyloxypropyl dihydrogen phosphate, 4-(meth)acryloyloxybutyl dihydrogen phosphate, 5-(meth)acryloyloxypentyl dihydrogen phosphate, 6-(meth)acryloyloxyhexyl dihydrogen phosphate, 7-(meth)acryloyloxyheptyl dihydrogen phosphate, 8-(meth)acryloyloxyethyl dihydrogen phosphate, 9-(meth)acryloyloxypropyl dihydrogen phosphate, 10-(meth)acryloyloxybutyl dihydrogen phosphate, 11-(meth)acryloyloxybutyl dihydrogen phosphate, 12-(meth)acryloyloxybutyl dihydrogen phosphate, 13-(meth)acryloyloxybutyl dihydrogen phosphate, 14-(meth)acryloyloxybutyl dihydrogen phosphate, 15-(meth)acryloyloxypentyl dihydrogen phosphate, 16-(meth)acryloyloxyhexyl dihydrogen phosphate, 17-(meth)acryloyloxyheptyl dihydrogen phosphate, 18-(meth)acryloyloxybutyl dihydrogen phosphate, 19-(meth)acryloyloxybutyl dihydrogen phosphate, 20-(meth)acryloyloxybutyl dihydrogen phosphate, 21-(meth)acryloyloxybutyl dihydrogen phosphate, 22-(meth)acryloyloxybutyl dihydrogen phosphate, 23-(meth)acryloyloxybutyl dihydrogen phosphate, 24-(meth)acryloyloxybutyl dihydrogen phosphate, 25-(meth)acryloyloxybutyl dihydrogen phosphate, 26-(meth)acryloyloxyhexyl dihydrogen phosphate, 27-(meth)acryloyloxyhexyl dihydrogen phosphate, 2 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 ester, bis[2-(meth)acryloyloxyethyl]hydrogenphosphate, bis[4-(meth)acryloyloxybutyl]hydrogenphosphate, bis[6-(meth)acryloyloxyhexyl]hydrogenphosphate, bis[8-(meth)acryloyloxyoctyl]hydrogenphosphate, bis[9-(meth)acryloyloxynonyl]hydrogenphosphate, bis[10-(meth)acryloyloxydecyl]hydrogenphosphate, 1,3-di(meth)acryloyloxyethyl]hydrogenphosphate, Examples include acryloyloxypropyl dihydrogen phosphate, 2-(meth)acryloyloxyethyl phenyl hydrogen phosphate, 2-(meth)acryloyloxyethyl-(2-bromoethyl)hydrogen phosphate, 2-(meth)acryloyloxyethyl-(4-methoxyphenyl)hydrogen phosphate, 2-(meth)acryloyloxypropyl-(4-methoxyphenyl)hydrogen phosphate, and acid chlorides, alkali metal salts and amine salts thereof.

[0036] Examples of the polymerizable monomer having a pyrophosphate group include bis[2-(meth)acryloyloxyethyl] pyrophosphate, bis[4-(meth)acryloyloxybutyl] pyrophosphate, bis[6-(meth)acryloyloxyhexyl] pyrophosphate, bis[8-(meth)acryloyloxyoctyl] pyrophosphate, bis[10-(meth)acryloyloxydecyl] pyrophosphate, and acid chlorides, alkali metal salts, and amine salts thereof.

[0037] Examples of the polymerizable monomer having a thiophosphate group include 2-(meth)acryloyloxyethyl dihydrogen thiophosphate, 3-(meth)acryloyloxypropyl dihydrogen thiophosphate, 4-(meth)acryloyloxybutyl dihydrogen thiophosphate, 5-(meth)acryloyloxypentyl dihydrogen thiophosphate, 6-(meth)acryloyloxyhexyl dihydrogen thiophosphate, 7-(meth)acryloyloxyheptyl dihydrogen thiophosphate, and 8-(meth)acryloyloxyoctyl dihydrogen thiophosphate. thiophosphate, 9-(meth)acryloyloxynonyl dihydrogen thiophosphate, 10-(meth)acryloyloxydecyl dihydrogen thiophosphate, 11-(meth)acryloyloxyundecyl dihydrogen thiophosphate, 12-(meth)acryloyloxydodecyl dihydrogen thiophosphate, 16-(meth)acryloyloxyhexadecyl dihydrogen thiophosphate, 20-(meth)acryloyloxyicosyl dihydrogen thiophosphate, and acid chlorides, alkali metal salts, and ammonium salts thereof.

[0038] Examples of the polymerizable monomer having a phosphonic acid group include 2-(meth)acryloyloxyethyl phenylphosphonate, 5-(meth)acryloyloxypentyl-3-phosphonopropionate, 6-(meth)acryloyloxyhexyl-3-phosphonopropionate, 10-(meth)acryloyloxydecyl-3-phosphonopropionate, 6-(meth)acryloyloxyhexyl phosphonoacetate, 10-(meth)acryloyloxydecyl-3-phosphonoacetate, and acid chlorides, alkali metal salts, and ammonium salts thereof.

[0039] Examples of the polymerizable monomer having a carboxylic acid group include monofunctional (meth)acrylic acid esters having one carboxyl group or an acid anhydride group thereof in the molecule, monofunctional (meth)acrylic acid esters having multiple carboxyl groups or acid anhydride groups thereof in the molecule, and acid chlorides, alkali metal salts, and ammonium salts thereof.

[0040] Examples of the monofunctional polymerizable monomer having one carboxyl group or an acid anhydride group thereof in the molecule include (meth)acrylic acid, N-(meth)acryloylglycine, N-(meth)acryloylaspartic acid, 2-(meth)acryloyloxyethyl hydrogen succinate, 2-(meth)acryloyloxyethyl hydrogen phthalate, 2-(meth)acryloyloxyethyl hydrogen maleate, O-(meth)acryloyltyrosine, N-(meth)acryloyltyrosine, Examples of the acryloyloxybenzoic acid include acryloylphenylalanine, N-(meth)acryloyl-p-aminobenzoic acid, N-(meth)acryloyl-o-aminobenzoic acid, 2-(meth)acryloyloxybenzoic acid, 3-(meth)acryloyloxybenzoic acid, 4-(meth)acryloyloxybenzoic acid, N-(meth)acryloyl-5-aminosalicylic acid, and N-(meth)acryloyl-4-aminosalicylic acid, as well as compounds in which the carboxyl group of these compounds has been converted to an acid anhydride group.

[0041] Examples of monofunctional polymerizable monomers having a plurality of carboxyl groups or acid anhydride groups thereof in the molecule include 6-(meth)acryloyloxyhexane-1,1-dicarboxylic acid, 9-(meth)acryloyloxynonane-1,1-dicarboxylic acid, 10-(meth)acryloyloxydecane-1,1-dicarboxylic acid, 11-(meth)acryloyloxyundecane-1,1-dicarboxylic acid, 12-(meth)acryloyloxydodecane-1,1-dicarboxylic acid, 13-(meth)acryloyloxytridecane-1,1-dicarboxylic acid, 4-(meth)acryloyloxyethyl trimellitate, 4-(meth)acryloyloxyethyl trimellitate anhydride ... butyl trimellitate, 4-(meth)acryloyloxyhexyl trimellitate, 4-(meth)acryloyloxydecyl trimellitate, 2-(meth)acryloyloxyethyl-3'-(meth)acryloyloxy-2'-(3,4-dicarboxybenzoyloxy)propyl succinate, 6-(meth)acryloyloxyethylnaphthalene-1,2,6-tricarboxylic anhydride, 6-(meth)acryloyloxyethylnaphthalene-2,3,6-tricarboxylic anhydride, 4-(meth)acryloyloxyethylcarbonylpropionoyl-1,8-naphthalic anhydride, 4-(meth)acryloyloxyethylnaphthalene-1,8-tricarboxylic anhydride, and the like.

[0042] Examples of the polymerizable monomer having a sulfonic acid group include 2-sulfoethyl (meth)acrylate and its acid chlorides, alkali metal salts, and ammonium salts.

[0043] Among these polymerizable monomers (B-1) having an acidic group, from the viewpoint of good adhesive strength when used in a dental composition, polymerizable monomers having a phosphoric acid group or polymerizable monomers having a carboxylic acid group are preferred, and examples thereof include 2-(meth)acryloyloxyethyl dihydrogen phosphate, 3-(meth)acryloyloxypropyl dihydrogen phosphate, 4-(meth)acryloyloxybutyl dihydrogen phosphate, 5-(meth)acryloyloxypentyl dihydrogen phosphate, 6-(meth)acryloyloxyhexyl dihydrogen phosphate, 7-(meth)acryloyloxyheptyl dihydrogen phosphate, 8-(meth)acryloyloxy Octyl 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, 4-(meth)acryloyloxyethyl trimellitate anhydride, 4-(meth)acryloyloxyethyl trimellitate, 11-(meth)acryloyloxyundecane-1,1-Dicarboxylic acid and a mixture of 2-(meth)acryloyloxyethyl dihydrogen phosphate and bis(2-methacryloyloxyethyl)hydrogen phosphate are more preferred, with 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, and 20-(meth)acryloyloxyicosyl dihydrogen phosphate being even more preferred, with 10-(meth)acryloyloxydecyl dihydrogen phosphate being the most preferred from the viewpoint of a balance of curability.

[0044] In addition, the content of the polymerizable monomer (B-1) having an acidic group in the dental composition of the present invention is preferably 0 parts by mass or more and 35 parts by mass or less, per 100 parts by mass of the total polymerizable monomer (B); from the viewpoint of adhesion to tooth structure, it is more preferably 1 part by mass or more and 30 parts by mass or less, even more preferably 5 parts by mass or more and 25 parts by mass or less, and particularly preferably 5 parts by mass or more and 20 parts by mass or less.

[0045] <Polymerizable Monomer (B-2) Not Having an Acidic Group> The polymerizable monomer (B-2) not having an acidic group in the present invention can be divided into hydrophilic polymerizable monomers (B-2a) not having an acidic group, which have a solubility of 4.5 g / L or more in water at 25° C., and hydrophobic polymerizable monomers (B-2b) not having an acidic group, which have a solubility of less than 4.5 g / L in water at 25° C. The polymerizable monomer (B-2) not having an acidic group may be used alone or in combination of two or more. In one preferred embodiment, the dental composition includes a polymerizable monomer (B) that does not have an acidic group (B-2), and the polymerizable monomer (B-2) that does not have an acidic group includes a hydrophilic polymerizable monomer (B-2a) that does not have an acidic group and has a solubility in water at 25°C of 4.5 g / L or more and / or a hydrophobic polymerizable monomer (B-2b) that does not have an acidic group and has a solubility in water at 25°C of less than 4.5 g / L.

[0046] Hydrophilic polymerizable monomer (B-2a) having no acidic group In the dental composition of the present invention, the polymerizable monomer (B) is a hydrophilic polymerizable monomer (B-2a) having no acidic group (hereinafter, may be simply referred to as "hydrophilic polymerizable monomer (B-2a)"), which means a monomer having no acidic group and a solubility of 4.5 g / L or more in water at 25° C. One type of hydrophilic polymerizable monomer (B-2a) may be used alone, or two or more types may be used in combination.

[0047] The hydrophilic polymerizable monomer (B-2a) improves the wettability of the dental composition to tooth structure. As the hydrophilic polymerizable monomer (B-2a), a radical polymerizable monomer having no acidic group but a polymerizable group is preferred, and from the viewpoint of ease of radical polymerization, the polymerizable group is preferably a (meth)acryloyloxy group and / or a (meth)acrylamide group. Examples of the hydrophilic polymerizable monomer (B-2a) include hydrophilic (meth)acrylate-based monofunctional polymerizable monomers such as 2-hydroxyethyl (meth)acrylate, 3-hydroxypropyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, 1,3-dihydroxypropyl (meth)acrylate, 2,3-dihydroxypropyl (meth)acrylate, 2-((meth)acryloyloxy)ethyltrimethylammonium chloride, and tetrahydrofurfuryl (meth)acrylate; triethylene glycol di(meth)acrylate, tetraethylene glycol di(meth)acrylate, nonaethylene glycol di(meth)acrylate, 1,3-bis(methacryloyloxy)-2-propanol, 1,2 and hydrophilic (meth)acrylate-based polyfunctional polymerizable monomers such as N-bis(3-methacryloyloxy-2-hydroxypropoxy)ethane; and hydrophilic (meth)acrylamide-based polymerizable monomers such as N-methylol(meth)acrylamide, N-hydroxyethyl(meth)acrylamide, N,N-bis(2-hydroxyethyl)(meth)acrylamide, N-methoxymethyl(meth)acrylamide, N-ethoxymethyl(meth)acrylamide, diacetone(meth)acrylamide, 4-(meth)acryloylmorpholine, N-trihydroxymethyl-N-methyl(meth)acrylamide, N,N-dimethylacrylamide, N,N-diethylacrylamide, and N-methacryloyloxyethylacrylamide.

[0048] Among these hydrophilic polymerizable monomers (B-2a), it is preferable to use a (meth)acrylate-based polyfunctional polymerizable monomer from the viewpoint of hydrophilicity and curability. Among them, 2-hydroxyethyl methacrylate (commonly known as "HEMA"), N,N-diethylacrylamide (commonly known as "DEAA"), triethylene glycol dimethacrylate (commonly known as "3G"), 1,3-bis(methacryloyloxy)-2-propanol, and 1,2-bis(3-methacryloyloxy-2-hydroxypropoxy)ethane (commonly known as "#801") are more preferable, and 3G and #801 are even more preferable.

[0049] The content of the hydrophilic polymerizable monomer (B-2a) in the dental composition of the present invention is preferably 0 parts by mass or more, based on 100 parts by mass of the total polymerizable monomers (B). From the viewpoint of adhesiveness, it is more preferably 5 parts by mass or more, even more preferably 10 parts by mass or more, and particularly preferably 15 parts by mass or more. Furthermore, from the viewpoint of adhesiveness, the content of the hydrophilic polymerizable monomer (B-2a) is preferably 60 parts by mass or less, more preferably 50 parts by mass or less, even more preferably 45 parts by mass or less, and particularly preferably 40 parts by mass or less, based on 100 parts by mass of the total polymerizable monomers (B). In particular, when the dental composition of the present invention is used as a dental bonding material, it is preferable to include the hydrophilic polymerizable monomer (B-2a). When the dental composition of the present invention is used as a dental bonding material, it is preferable that the content of the hydrophilic polymerizable monomer (B-2a) is 5 parts by mass or more and 60 parts by mass or less, based on 100 parts by mass of the total polymerizable monomers (B). When the dental composition of the present invention is used as a dental composite resin, it may not contain the hydrophilic polymerizable monomer (B-2a). That is, the content of the hydrophilic polymerizable monomer (B-2a) may be 0 parts by mass relative to 100 parts by mass of the total amount of the polymerizable monomers (B).

[0050] Hydrophobic Polymerizable Monomer (B-2b) Having No Acidic Group In the dental composition of the present invention, from the viewpoint of the mechanical strength of the cured product, it is preferable that the polymerizable monomer (B) contains a hydrophobic polymerizable monomer (B-2b) having no acidic group (hereinafter, sometimes simply referred to as "hydrophobic polymerizable monomer (B-2b)"). The hydrophobic polymerizable monomer (B-2b) refers to a monomer that does not have an acidic group and has a solubility in water at 25°C of less than 4.5 g / L. The use of the hydrophobic polymerizable monomer (B-2b) improves the mechanical strength of the cured product of the dental composition and reduces stringiness (ease of stringing) when used as a dental composite resin. The hydrophobic polymerizable monomer (B-2b) may be blended alone or in combination of two or more types.

[0051] The hydrophobic polymerizable monomer (B-2b) is preferably a radically polymerizable monomer having a polymerizable group but no acidic group, and from the viewpoint of ease of radical polymerization, the polymerizable group is preferably a (meth)acryloyloxy group and / or a (meth)acrylamide group. Examples of the hydrophobic polymerizable monomer (B-2b) include crosslinkable polymerizable monomers such as hydrophobic monofunctional polymerizable monomers, hydrophobic aromatic compound-based bifunctional polymerizable monomers, hydrophobic aliphatic compound-based bifunctional polymerizable monomers, and hydrophobic trifunctional or higher functional polymerizable monomers, as well as polyfunctional polymerizable monomers containing a urethane bond and a polymer skeleton. In this specification, even if a hydrophobic aromatic compound-based bifunctional polymerizable monomer, a hydrophobic aliphatic compound-based bifunctional polymerizable monomer, or a hydrophobic trifunctional or higher functional polymerizable monomer is included in the polyfunctional polymerizable monomer containing a urethane bond and a polymer skeleton, it is treated as a polyfunctional polymerizable monomer containing a urethane bond and a polymer skeleton. In other words, a hydrophobic aromatic compound-based bifunctional polymerizable monomer, a hydrophobic aliphatic compound-based bifunctional polymerizable monomer, or a hydrophobic trifunctional or higher functional polymerizable monomer does not include a polyfunctional polymerizable monomer containing a urethane bond and a polymer skeleton.

[0052] Examples of hydrophobic monofunctional polymerizable monomers include aliphatic compound-based monofunctional (meth)acrylate monomers such as methyl (meth)acrylate, ethyl (meth)acrylate, butyl (meth)acrylate, and n-stearyl methacrylate; ether bond-containing aliphatic compound-based monofunctional (meth)acrylate monomers such as butoxydiethylene glycol methacrylate and methoxypolyethylene glycol methacrylate (average number of moles of oxyethylene groups added: 9); cyclohexyl methacrylate, isobornyl methacrylate, and the like. Examples of suitable (meth)acrylate monomers include monofunctional (meth)acrylate monomers based on alicyclic compounds such as acrylate and dicyclopentanyl methacrylate; monofunctional (meth)acrylate monomers having an aromatic ring group such as p-cumyl-phenoxyethylene glycol (meth)acrylate, benzyl (meth)acrylate, phenoxybenzyl (meth)acrylate, and 2-phenoxyethyl (meth)acrylate; and (meth)acrylate monomers containing a heterocyclic group (e.g., a cyclic ether group) such as tetrahydrofurfuryl (meth)acrylate. Preferred monofunctional (meth)acrylate monomers having an aromatic ring group are those having one or two phenyl groups. Preferred (meth)acrylate monomers containing a heterocyclic group are those having one or two heterocyclic groups (e.g., a cyclic ether group). Of these, tetrahydrofurfuryl methacrylate (commonly known as THF-MA), benzyl methacrylate (commonly known as BEMA), phenoxybenzyl methacrylate (commonly known as POB-MA), and 2-phenoxyethyl methacrylate (commonly known as PEMA) are preferred from the viewpoint of the mechanical strength of the cured product.

[0053] Examples of hydrophobic aromatic compound-based bifunctional polymerizable monomers include 2,2-bis((meth)acryloyloxyphenyl)propane, 2,2-bis[4-(2-hydroxy-3-(meth)acryloyloxypropoxy)phenyl]propane, 2,2-bis(4-(meth)acryloyloxyethoxyphenyl)propane, 2,2-bis(4-(meth)acryloyloxypolyethoxyphenyl)propane, 2,2-bis(4-(meth)acryloyloxydiethoxyphenyl)propane, 2,2-bis(4-(meth)acryloyloxytriethoxyphenyl)propane, 2,2-bis(4-(meth)acryloyloxytetraethoxyphenyl)propane, 2,2-bis(4-(meth)acryloyloxypentaethoxyphenyl)propane, and 2,2-bis(4-(meth)acryloyloxypentaethoxyphenyl)propane. 2-(4-(meth)acryloyloxydipropoxyphenyl)propane, 2,2-bis(4-(meth)acryloyloxydiethoxyphenyl)-2-(4-(meth)acryloyloxyethoxyphenyl)propane, 2-(4-(meth)acryloyloxydiethoxyphenyl)-2-(4-(meth)acryloyloxytriethoxyphenyl)propane, 2-(4-(meth)acryloyloxydipropoxyphenyl)-2-(4-(meth)acryloyloxytriethoxyphenyl)propane, 2,2-bis(4-(meth)acryloyloxypropoxyphenyl)propane, 2,2-bis(4-(meth)acryloyloxyisopropoxyphenyl)propane, and the like. Among these, 2,2-bis[4-(2-hydroxy-3-methacryloyloxypropoxy)phenyl]propane (commonly known as "Bis-GMA"), 2,2-bis(4-methacryloyloxyethoxyphenyl)propane, 2,2-bis(4-methacryloyloxypolyethoxyphenyl)propane (average number of moles of ethoxy groups added: 2.6, commonly known as "D-2.6E"), 2,2-bis(4-methacryloyloxydiethoxyphenyl)propane, 2,2-bis(4-methacryloyloxytriethoxyphenyl)propane, 2,2-bis(4-methacryloyloxytetraethoxyphenyl)propane, and 2,2-bis(4-methacryloyloxypentaethoxyphenyl)propane are preferred, and Bis-GMA and D-2.6E are more preferred.

[0054] Examples of the aliphatic compound-based bifunctional polymerizable monomer include monoethylene glycol di(meth)acrylate, diethylene glycol di(meth)acrylate, propylene glycol di(meth)acrylate, butylene glycol di(meth)acrylate, neopentyl glycol di(meth)acrylate, 1,5-pentanediol di(meth)acrylate, 1,6-hexanediol di(meth)acrylate, 1,10-decanediol di(meth)acrylate, and 2,2,4-trimethylhexamethylenebis(2-carbamoyloxyethyl)di(meth)acrylate. Among these, neopentyl glycol dimethacrylate (commonly known as "NPG"), 2,2,4-trimethylhexamethylenebis(2-carbamoyloxyethyl)dimethacrylate (commonly known as "UDMA"), N-methacryloyloxyethyl acrylamide (commonly known as "MAEA"), 1,10-decanediol dimethacrylate (commonly known as "DD"), and 2,2,4-trimethylhexamethylenebis(2-carbamoyloxyethyl)dimethacrylate are preferred, with NPG, UDMA, and DD being more preferred.

[0055] Examples of trifunctional or higher functional polymerizable monomers include trimethylolpropane tri(meth)acrylate, trimethylolethane tri(meth)acrylate, trimethylolmethane tri(meth)acrylate, pentaerythritol tri(meth)acrylate, pentaerythritol tetra(meth)acrylate, dipentaerythritol penta(meth)acrylate, N,N-(2,2,4-trimethylhexamethylene)bis[2-(aminocarboxy)propane-1,3-diol]tetra(meth)acrylate, and 1,7-diacryloyloxy-2,2,6,6-tetra(meth)acryloyloxymethyl-4-oxaheptane. Of these, N,N-(2,2,4-trimethylhexamethylene)bis[2-(aminocarboxy)propane-1,3-diol]tetramethacrylate is preferred.

[0056] Examples of polyfunctional polymerizable monomers containing a urethane bond and a polymer skeleton include urethane-modified (meth)acrylate polymerizable monomers in which a urethane bond is introduced adjacent to a (meth)acryloyloxy group and which have at least one structure selected from the group consisting of polyester, polycarbonate, polyurethane, polyether, polyconjugated diene, and hydrogenated polyconjugated diene in one molecule (hereinafter, these may also be referred to as "polymer skeleton"). Among these, those containing an aromatic ring in the repeating unit constituting the polymer skeleton are preferred in terms of excellent flexibility.

[0057] A urethane-modified (meth)acrylate-based polyfunctional polymerizable monomer having a polymer skeleton can be easily synthesized, for example, by subjecting a polyol containing the polymer skeleton, a compound having an isocyanate group (—NCO), and a (meth)acrylate compound having a hydroxyl group (—OH). Alternatively, a urethane-modified (meth)acrylate-based polyfunctional polymerizable monomer having a polymer skeleton can be easily synthesized by subjecting a (meth)acrylate compound having a hydroxyl group to a ring-opening addition reaction with a lactone or an alkylene oxide, and then subjecting the resulting compound having a hydroxyl group at one end to an addition reaction with a compound having an isocyanate group.

[0058] The polyol containing the polymer skeleton is not particularly limited as long as it has the above structure. For example, polyesters include polymers of phthalic acid and alkylene diols having 2 to 12 carbon atoms, polymers of adipic acid and alkylene glycols having 2 to 12 carbon atoms, polymers of maleic acid and alkylene diols having 2 to 12 carbon atoms, polymers of β-propiolactone, polymers of γ-butyrolactone, polymers of δ-valerolactone, polymers of ε-caprolactone, and copolymers thereof. Polycarbonates include polycarbonates derived from aliphatic diols having 2 to 12 carbon atoms, polycarbonates derived from bisphenol A, and polycarbonates derived from aliphatic diols having 2 to 12 carbon atoms and bisphenol A. Polyurethanes include polymers of aliphatic diols having 2 to 12 carbon atoms and diisocyanates having 1 to 12 carbon atoms. Polyethers include polyethylene glycol, polypropylene glycol, polybutylene glycol, and poly(1-methylbutylene glycol). The polyconjugated dienes and hydrogenated polyconjugated dienes include 1,4-polybutadiene, 1,2-polybutadiene, polyisoprene, poly(butadiene-isoprene), poly(butadiene-styrene), poly(isoprene-styrene), polyfarnesene, and hydrogenated versions thereof.

[0059] Examples of compounds having an isocyanate group include hexamethylene diisocyanate (HDI), tolylene diisocyanate (TDI), xylylene diisocyanate (XDI), diphenylmethane diisocyanate (MDI), isophorone diisocyanate (IPDI), trimethylhexamethylene diisocyanate (TMHMDI), tricyclodecane diisocyanate (TCDDI), and adamantane diisocyanate (ADI).

[0060] Examples of the (meth)acrylate compound having a hydroxyl group include hydroxy(meth)acrylate compounds such as 2-hydroxyethyl(meth)acrylate, 2-hydroxypropyl(meth)acrylate, 2-hydroxybutyl(meth)acrylate, 6-hydroxyhexyl(meth)acrylate, 10-hydroxydecyl(meth)acrylate, 3-chloro-2-hydroxypropyl(meth)acrylate, 2-hydroxy-3-phenoxypropyl(meth)acrylate, glycerin mono(meth)acrylate, 2-hydroxy-3-acryloyloxypropyl(meth)acrylate, 2,2-bis[4-[3-(meth)acryloyloxy-2-hydroxypropoxy]phenyl]propane, 1,2-bis[3-(meth)acryloyloxy-2-hydroxypropoxy]ethane, pentaerythritol tri(meth)acrylate, and dipentaerythritol tri- or tetra(meth)acrylate.

[0061] The addition reaction between a compound having an isocyanate group and a (meth)acrylate compound having a hydroxyl group can be carried out according to a known method, and is not particularly limited.

[0062] Examples of the urethane-modified (meth)acrylate-based polyfunctional polymerizable monomer having a polymer skeleton obtained by the above-mentioned method include reaction products of any combination of the above-mentioned polyol having at least one structure selected from the group consisting of polyester, polycarbonate, polyurethane, polyether, polyconjugated diene, and hydrogenated polyconjugated diene, a compound having an isocyanate group, and a (meth)acrylate compound having a hydroxyl group. Commercially available products can also be used as the urethane-modified (meth)acrylate-based polyfunctional polymerizable monomer having a polymer skeleton. Examples of commercially available products include urethane acrylates such as "UFC-01" (manufactured by Kyoeisha Chemical Co., Ltd.), "EBECRYL8465" (manufactured by Daicel Allnex Corporation), and "UN7600" (manufactured by Negami Chemical Industrial Co., Ltd.).

[0063] The weight average molecular weight (Mw) of the urethane-type (meth)acrylate polyfunctional polymerizable monomer having a polymer skeleton is, from the viewpoints of viscosity and strength, preferably from 500 to 50,000, more preferably from 750 to 30,000, and even more preferably from 1,000 to 15,000. Note that the weight average molecular weight (Mw) in the present invention means the weight average molecular weight in terms of polystyrene determined by gel permeation chromatography (GPC).

[0064] Among these hydrophobic polymerizable monomers (B-2b), aromatic compound-based bifunctional polymerizable monomers and aliphatic compound-based bifunctional polymerizable monomers are preferred from the viewpoints of handling properties and mechanical strength of the cured product.

[0065] Furthermore, if the content of the hydrophobic polymerizable monomer (B-2b) in the dental composition of the present invention is excessive, the wettability of the dental composition to tooth structure may decrease, resulting in decreased adhesiveness, whereas if the content is too low, the mechanical strength of the cured product may be insufficient. Therefore, the content of the hydrophobic polymerizable monomer (B-2b) in the dental composition of the present invention is preferably 40 parts by mass or more, more preferably 45 parts by mass or more, even more preferably 50 parts by mass or more, and particularly preferably 55 parts by mass or more, per 100 parts by mass of the total polymerizable monomers (B).

[0066] [Photopolymerization initiator (C)] The dental composition of the present invention contains a photopolymerization initiator (C). There are no particular limitations on the type of photopolymerization initiator (C), and conventionally known photopolymerization initiators can be used without any limitations. Examples of the photopolymerization initiator (C) include α-diketones, ketals, thioxanthones, (bis)acylphosphine oxides, and α-aminoacetophenones. One type of photopolymerization initiator (C) may be used alone, or two or more types may be used in combination.

[0067] Examples of α-diketones include dl-camphorquinone (commonly known as "CQ"), benzil, and 2,3-pentanedione.

[0068] Examples of the ketals include benzyl dimethyl ketal and benzyl diethyl ketal.

[0069] The thioxanthones include 2-chlorothioxanthone and 2,4-diethylthioxanthone.

[0070] Examples of (bis)acylphosphine oxides include 2,4,6-trimethylbenzoyldiphenylphosphine oxide, bis(2,4,6-trimethylbenzoyl)phenylphosphine oxide, dibenzoylphenylphosphine oxide, bis(2,6-dimethoxybenzoyl)phenylphosphine oxide, tris(2,4-dimethylbenzoyl)phosphine oxide, tris(2-methoxybenzoyl)phosphine oxide, 2,6-dimethoxybenzoyldiphenylphosphine oxide, 2,6-dichloro Examples of the acylphosphine oxide include benzoyldiphenylphosphine oxide, 2,3,5,6-tetramethylbenzoyldiphenylphosphine oxide, benzoyl-bis(2,6-dimethylphenyl)phosphine oxide, 2,4,6-trimethylbenzoylethoxyphenylphosphine oxide, and the water-soluble acylphosphine oxide compounds disclosed in JP-B-3-57916, as well as salts thereof (for example, alkali metal salts such as sodium salts (for example, sodium bis(2,4,6-trimethylbenzoyl)phosphinate)).

[0071] Examples of α-aminoacetophenones include 2-benzyl-2-dimethylamino-1-(4-morpholinophenyl)-1-butanone, 2-benzyl-2-diethylamino-1-(4-morpholinophenyl)-1-butanone, 2-benzyl-2-dimethylamino-1-(4-morpholinophenyl)-1-propanone, 2-benzyl-2-diethylamino-1-(4-morpholinophenyl)-1-propanone, 2-benzyl-2-dimethylamino-1-(4-morpholinophenyl)-1-pentanone, and 2-benzyl-2-diethylamino-1-(4-morpholinophenyl)-1-pentanone.

[0072] Among these, from the viewpoint of curability and the like, the photopolymerization initiator (C) is preferably an α-diketone and / or a (bis)acylphosphine oxide, more preferably an α-diketone, and even more preferably dl-camphorquinone.

[0073] From the viewpoint of curability and storage stability, the content of the photopolymerization initiator (C) is preferably 0.005 parts by mass or more, more preferably 0.01 parts by mass or more, and even more preferably 0.1 parts by mass or more, relative to 100 parts by mass of the total of the polymerizable monomers (B). From the viewpoint of curability and storage stability, the content of the photopolymerization initiator (C) is preferably 10 parts by mass or less, more preferably 5 parts by mass or less, and even more preferably 3 parts by mass or less. The mass ratio (A):(C) of the content of the ultraviolet absorber (A) to the content of the photopolymerization initiator (C) is preferably 1:0.01 to 1:80. From the viewpoint of excellent storage stability and excellent environmental light stability and photocurability under high illuminance, it is more preferably 1:0.1 to 1:50, even more preferably 1:0.5 to 1:30, particularly preferably 1:1 to 1:25, and most preferably 1:1.5 to 1:25.

[0074] [Polymerization accelerator (D)] The dental composition of the present invention preferably further contains a polymerization accelerator (D). The polymerization accelerator (D) is not particularly limited, and examples thereof include amines, aldehydes, and thiol compounds. The polymerization accelerator (D) may be used alone or in combination of two or more.

[0075] The amines include aliphatic amines and aromatic amines.

[0076] Examples of aliphatic amines include primary aliphatic amines such as n-butylamine, n-hexylamine, and n-octylamine; secondary aliphatic amines such as diisopropylamine, dibutylamine, and N-methylethanolamine; and tertiary aliphatic amines such as N-methyldiethanolamine, N-ethyldiethanolamine, N-n-butyldiethanolamine, N-lauryldiethanolamine, 2-(dimethylamino)ethyl(meth)acrylate, N-methyldiethanolamine di(meth)acrylate, N-ethyldiethanolamine di(meth)acrylate, triethanolamine tri(meth)acrylate, triethanolamine, trimethylamine, triethylamine, and tributylamine. Among these, tertiary aliphatic amines are preferred in terms of photocurability, and N-methyldiethanolamine, triethanolamine, and 2-(dimethylamino)ethyl methacrylate are particularly preferred.

[0077] Examples of aromatic amines include aromatic amines having an electron-withdrawing group on the aromatic ring and aromatic amines not having an electron-withdrawing group on the aromatic ring.

[0078] Examples of aromatic amines having an electron-withdrawing group on the aromatic ring include tertiary aromatic amines having an electron-withdrawing group on the aromatic ring, such as n-butoxyethyl 4-(N,N-dimethylamino)benzoate, (2-methacryloyloxy)ethyl 4-(N,N-dimethylamino)benzoate, ethyl 4-(N,N-dimethylamino)benzoate (hereinafter sometimes abbreviated as "DABE"), butyl 4-(N,N-dimethylamino)benzoate, and 4-(N,N-dimethylamino)benzophenone.

[0079] Examples of aromatic amines that do not have an electron-withdrawing group in the aromatic ring include N,N-bis(2-hydroxyethyl)-3,5-dimethylaniline, N,N-bis(2-hydroxyethyl)-p-toluidine (hereinafter sometimes abbreviated as "DEPT"), 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, and N,N-bis(2-hydroxyethyl)-3,5-diisopropylaniline. and aromatic tertiary amines not having an electron-withdrawing group on the aromatic ring, such as N,N-bis(2-hydroxyethyl)-3,5-di-t-butylaniline, N,N-dimethylaniline, N,N-dimethyl-p-toluidine, N,N-dimethyl-m-toluidine, N,N-diethyl-p-toluidine, N,N-dimethyl-3,5-dimethylaniline, N,N-dimethyl-3,4-dimethylaniline, N,N-dimethyl-4-ethylaniline, N,N-dimethyl-4-isopropylaniline, N,N-dimethyl-4-t-butylaniline, and N,N-dimethyl-3,5-di-t-butylaniline.

[0080] Among these, from the viewpoint of being able to impart excellent curability to the dental composition, at least one selected from the group consisting of N,N-bis(2-hydroxyethyl)-p-toluidine, ethyl 4-(N,N-dimethylamino)benzoate, n-butoxyethyl 4-(N,N-dimethylamino)benzoate, and 4-(N,N-dimethylamino)benzophenone is preferred.

[0081] Examples of aldehydes include terephthalaldehyde and benzaldehyde derivatives, such as dimethylaminobenzaldehyde, p-methoxybenzaldehyde, p-ethoxybenzaldehyde, and p-n-octyloxybenzaldehyde.

[0082] Examples of the thiol compound include 3-mercaptopropyltrimethoxysilane, 2-mercaptobenzoxazole, decanethiol, and thiobenzoic acid.

[0083] From the viewpoints of curability and storage stability, the content of the polymerization accelerator (D) is preferably 0.001 to 20 parts by mass, more preferably 0.01 to 15 parts by mass, and even more preferably 0.1 to 10 parts by mass, relative to 100 parts by mass of the total of the polymerizable monomers (B).

[0084] [Filler (E)] The dental composition of the present invention preferably further contains a filler (E).

[0085] As the filler (E), any filler can be used as long as it does not impair the effects of the present invention, and examples thereof include inorganic fillers, organic fillers, and composite fillers of inorganic fillers and organic fillers. The filler (E) may be used alone or in combination of two or more types.

[0086] The inorganic filler may be any of various glasses (mainly composed of silica, and optionally containing oxides of heavy metals, boron, aluminum, etc.). For example, glass powders of general compositions such as fused silica, quartz, soda lime silica glass, E glass, C glass, and borosilicate glass (Pyrex (registered trademark) glass); dental glass powders such as barium glass (manufactured by Schott, such as "GM27884" and "8235"; and "E-2000" and "E-3000" by Esstech), strontium borosilicate glass (manufactured by Esstech, such as "E-4000"), lanthanum glass ceramics (manufactured by Schott, such as "GM31684"), and fluoroaluminosilicate glass (manufactured by Schott, such as "GM35429", "G018-091", and "G018-117"); various ceramics; composite oxides such as silica-titania and silica-zirconia; diatomaceous earth, kaolin, clay minerals (montmorillonite, etc.); fluoride, etc.), activated clay, synthetic zeolite, mica, calcium fluoride, ytterbium fluoride, yttrium fluoride, calcium fluoride having a core-shell structure whose surface is coated with silica, ytterbium fluoride having a core-shell structure whose surface is coated with silica, yttrium fluoride having a core-shell structure whose surface is coated with silica, calcium phosphate, barium sulfate, zirconium dioxide, titanium dioxide, hydroxyapatite, calcium phosphate having a core-shell structure whose surface is coated with silica, barium sulfate having a core-shell structure whose surface is coated with silica, zirconium dioxide having a core-shell structure whose surface is coated with silica, titanium dioxide having a core-shell structure whose surface is coated with silica, and hydroxyapatite having a core-shell structure whose surface is coated with silica.Among these, from the viewpoint of strength and the like, various glasses, composite oxides such as silica-titania and silica-zirconia, calcium fluoride having a core-shell structure whose surface is coated with silica, ytterbium fluoride having a core-shell structure whose surface is coated with silica, yttrium fluoride having a core-shell structure whose surface is coated with silica, calcium phosphate having a core-shell structure whose surface is coated with silica, barium sulfate having a core-shell structure whose surface is coated with silica, zirconium dioxide having a core-shell structure whose surface is coated with silica, titanium dioxide having a core-shell structure whose surface is coated with silica, and hydroxyapatite having a core-shell structure whose surface is coated with silica are preferred.

[0087] As the inorganic filler, in terms of adhesiveness and handleability, fine particle silica having an average primary particle size of 0.001 to 10 μm is preferred. Commercially available products include "Aerosil (registered trademark) OX50", "Aerosil (registered trademark) 50", "Aerosil (registered trademark) 200", "Aerosil (registered trademark) 380", "Aerosil (registered trademark) R972", and "Aerosil (registered trademark) 130" (all of which are product names manufactured by Nippon Aerosil Co., Ltd.). In the present invention, when the inorganic filler is surface-treated as described below, the average particle size of the inorganic filler refers to the average particle size before the surface treatment.

[0088] Examples of organic fillers include polymethyl methacrylate, polyethyl methacrylate, methyl methacrylate-ethyl methacrylate copolymer, crosslinked polymethyl methacrylate, crosslinked polyethyl methacrylate, polyamide, polyvinyl chloride, polystyrene, chloroprene rubber, nitrile rubber, ethylene-vinyl acetate copolymer, styrene-butadiene copolymer, acrylonitrile-styrene copolymer, and acrylonitrile-styrene-butadiene copolymer.

[0089] Examples of composite fillers of inorganic and organic fillers include those in which inorganic fillers are dispersed in organic fillers, and inorganic / organic composite fillers in which inorganic fillers are coated with various polymers.

[0090] In this specification, the average particle size of the filler (E) can be determined by a laser diffraction scattering method or by observing the particles with an electron microscope. Specifically, the laser diffraction scattering method is convenient for measuring particle sizes of 0.1 μm or more, and electron microscope observation is convenient for measuring the particle size of ultrafine particles less than 0.1 μm. 0.1 μm means the value measured by the laser diffraction scattering method.

[0091] Specifically, the laser diffraction scattering method can be performed using a laser diffraction particle size distribution analyzer (model "SALD-2300", manufactured by Shimadzu Corporation) on a volume basis using a 0.2% aqueous solution of sodium hexametaphosphate as a dispersion medium.

[0092] Specifically, electron microscope observation can be performed by taking a photograph of the filler particles with a scanning electron microscope (S-4000 model, manufactured by Hitachi, Ltd.) and measuring the particle diameters of particles (200 or more) observed within a unit field of view of the photograph using image analysis particle size distribution measurement software (Mac-View (manufactured by Mountec Co., Ltd.)). In this case, the particle diameter of the particles is determined as the arithmetic mean value of the longest and shortest lengths of the particles, and the average particle diameter is calculated from the number of particles and their particle diameters.

[0093] When the dental composition of the present invention is used as a dental bonding material, the content of the filler (E) is preferably from 0 to 30% by mass, more preferably from 0.5 to 20% by mass, and even more preferably from 1 to 10% by mass, based on the total mass (100% by mass) of the dental composition, from the viewpoint of curability. Furthermore, when the dental composition of the present invention is used as a dental composite resin, the content of the filler (E) is preferably from 50 to 90% by mass, more preferably from 60 to 80% by mass, based on the total mass (100% by mass) of the dental composition, from the viewpoint of curability.

[0094] In order to improve the curability, mechanical strength and handling properties, the filler (E) may be used after being surface-treated in advance with a known surface treatment agent such as a silane coupling agent.

[0095] Examples of the surface treatment agent include silane coupling agents such as vinyltrimethoxysilane, vinyltriethoxysilane, vinyltrichlorosilane, vinyltri(β-methoxyethoxy)silane, γ-methacryloyloxypropyltrimethoxysilane, γ-glycidoxypropyltrimethoxysilane, γ-mercaptopropyltrimethoxysilane, and γ-aminopropyltriethoxysilane.

[0096] The dental composition of the present invention may contain a silane coupling agent other than the silane coupling agent used as a surface treatment agent for the filler (E).

[0097] The silane coupling agent may be used alone or in combination of two or more. Any known silane coupling agent can be used without limitation. Specific examples of the silane coupling agent include vinyltrimethoxysilane, vinyltriethoxysilane, vinyltrichlorosilane, vinyltri(β-methoxyethoxy)silane, γ-methacryloyloxypropyltrimethoxysilane, γ-glycidoxypropyltrimethoxysilane, γ-mercaptopropyltrimethoxysilane, γ-aminopropyltriethoxysilane, 5-(meth)acryloyloxypentyltrimethoxysilane, 6-(meth)acryloyloxyhexyltrimethoxysilane, and 7-(meth)acryloyloxyheptyltrimethoxysilane. Examples thereof include acryloyloxyoctyltrimethoxysilane, 8-(meth)acryloyloxyoctyltrimethoxysilane, 9-(meth)acryloyloxynonyltrimethoxysilane, 10-(meth)acryloyloxydecyltrimethoxysilane, 11-(meth)acryloyloxyundecyltrimethoxysilane, 8-(meth)acryloyloxyoctylmethyldimethoxysilane, 10-(meth)acryloyloxydecylmethyldimethoxysilane, 11-(meth)acryloyloxyundecylmethyldimethoxysilane, and (meth)acryloyloxymethylphenethyltrimethoxysilane.

[0098] From the viewpoint of adhesiveness, the content of the silane coupling agent is preferably 0.1 to 10.0 mass%, more preferably 0.5 to 9.0 mass%, even more preferably 1.0 to 8.0 mass%, and particularly preferably 1.2 to 7.0 mass%, relative to the total mass (100 mass%) of the dental composition of the present invention.

[0099] [Chemical Polymerization Initiator (F)] The dental composition of the present invention may contain a chemical polymerization initiator (F).

[0100] Examples of the chemical polymerization initiator (F) include peroxides (organic peroxides and inorganic peroxides). These are not particularly limited and known peroxides can be used. The chemical polymerization initiator (F) may be used alone or in combination of two or more.

[0101] Representative organic peroxides include hydroperoxides, peroxyesters, ketone peroxides, peroxyketals, dialkyl peroxides, diacyl peroxides, peroxydicarbonates, etc. Among these, hydroperoxides and peroxyesters are particularly preferred, and peroxyesters are most preferred because they show little change in the operable time even when the dental composition of the present invention is stored for a long period of time.

[0102] More specifically, examples of the hydroperoxide include cumene hydroperoxide, t-butyl hydroperoxide, t-hexyl hydroperoxide, p-menthane hydroperoxide, diisopropylbenzene hydroperoxide, and 1,1,3,3-tetramethylbutyl hydroperoxide (hereinafter sometimes abbreviated as "THP").

[0103] Any known peroxyester can be used without any restrictions as long as it has an acyl group on one side of a peroxy group (-OO- group) and a hydrocarbon group (or a group similar thereto) on the other side. Specific examples include α,α-bis(neodecanoylperoxy)diisopropylbenzene, cumyl peroxy neodecanoate, 1,1,3,3-tetramethylbutyl peroxy neodecanoate, 1-cyclohexyl-1-methylethyl peroxy neodecanoate, t-hexyl peroxy neodecanoate, t-butyl peroxy neodecanoate, t-hexyl peroxy pivalate, t-butyl peroxy pivalate, 1,1,3,3-tetramethylbutyl peroxy-2-ethylhexanoate, 2,5-dimethyl-2,5-bis(2-ethylhexanoylperoxy)hexane, 1-cyclohexyl-1-methylethyl peroxy-2-ethylhexanoate, t-hexyl peroxy-2-ethylhexanoate, t-butyl peroxy-2-ethylhexanoate, t- Examples of peroxybenzoates include butyl peroxyisobutyrate, t-hexylperoxyisopropyl monocarbonate, t-butylperoxymaleic acid, t-butylperoxy-3,5,5-trimethylhexanoate, t-butylperoxylaurate, 2,5-dimethyl-2,5-bis(m-toluoylperoxy)hexane, t-butylperoxyisopropyl monocarbonate, t-butylperoxy-2-ethylhexyl monocarbonate, t-hexylperoxybenzoate, 2,5-dimethyl-2,5-bis(benzoylperoxy)hexane, t-butylperoxyacetate, t-butylperoxy-m-toluoylbenzoate, t-butylperoxybenzoate (hereinafter sometimes abbreviated as "BPB"), and bis(t-butylperoxy)isophthalate. Among these, from the viewpoints of storage stability and reactivity, t-butylperoxymaleic acid, t-butylperoxy-3,5,5-trimethylhexanoate, t-butylperoxybenzoate, t-butylperoxyisopropyl monocarbonate, t-butylperoxy-2-ethylhexyl monocarbonate, and t-butylperoxyacetate are preferred, and t-butylperoxybenzoate is more preferred.

[0104] Examples of ketone peroxides include methyl ethyl ketone peroxide, cyclohexanone peroxide, methylcyclohexanone peroxide, methylacetoacetate peroxide, and acetylacetone peroxide.

[0105] Examples of peroxyketals include 1,1-bis(t-hexylperoxy)3,3,5-trimethylcyclohexane, 1,1-bis(t-hexylperoxy)cyclohexane, 1,1-bis(t-butylperoxy)3,3,5-trimethylcyclohexanone, 1,1-bis(t-butylperoxy)cyclohexane, 1,1-bis(t-butylperoxy)cyclodecane, 2,2-bis(t-butylperoxy)butane, n-butyl 4,4-bis(t-butylperoxy)valerate, and 2,2-bis(4,4-di-t-butylperoxycyclohexyl)propane.

[0106] Examples of dialkyl peroxides include α,α-bis(t-butylperoxy)diisopropylbenzene, dicumyl peroxide, 2,5-dimethyl-2,5-bis(t-butylperoxy)hexane, t-butylcumyl peroxide, di-t-butyl peroxide, and 2,5-dimethyl-2,5-bis(t-butylperoxy)3-hexyne.

[0107] Examples of diacyl peroxides include isobutyryl peroxide, 2,4-dichlorobenzoyl peroxide, 3,5,5-trimethylhexanoyl peroxide, octanoyl peroxide, lauroyl peroxide, stearyl peroxide, succinic acid peroxide, m-toluoylbenzoyl peroxide, and benzoyl peroxide.

[0108] Examples of peroxydicarbonates include di-n-propyl peroxydicarbonate, diisopropyl peroxydicarbonate, bis(4-t-butylcyclohexyl)peroxydicarbonate, di(2-ethoxyethyl)peroxydicarbonate, di(2-ethylhexyl)peroxydicarbonate, di(2-methoxybutyl)peroxydicarbonate, and di(3-methyl-3-methoxybutyl)peroxydicarbonate.

[0109] Examples of inorganic peroxides include peroxodisulfates and peroxodiphosphates, and among these, peroxodisulfates are preferred in terms of curability. Specific examples of peroxodisulfates include sodium peroxodisulfate, potassium peroxodisulfate (hereinafter sometimes abbreviated as "KPS"), aluminum peroxodisulfate, and ammonium peroxodisulfate.

[0110] From the viewpoint of curability, the content of the organic peroxide and the inorganic peroxide is preferably 0.01 to 5 parts by mass, and more preferably 0.05 to 2 parts by mass, per 100 parts by mass of the total of the polymerizable monomers (B) in the dental composition of the present invention.

[0111] [Chemical Polymerization Accelerator (G)] Examples of the chemical polymerization accelerator (G) used in the dental composition of the present invention include fourth-period transition metal compounds, transition metal compounds other than those of the fourth period, thiourea compounds, tin compounds, aromatic sulfinic acids and their salts, benzotriazole compounds, benzimidazole compounds, bromides, borate compounds, barbituric acid compounds, ascorbic acid compounds, sulfur-containing reducing inorganic compounds, etc. The chemical polymerization accelerator (G) may be used alone or in combination of two or more.

[0112] In one embodiment, when the polymerizable monomer (B) does not contain a polymerizable monomer (B-1) having an acidic group, the chemical polymerization accelerator (G) is preferably at least one selected from the group consisting of a fourth-period transition metal compound, a transition metal compound other than a fourth-period transition metal compound, and a thiourea compound. In the above embodiment, the content of the chemical polymerization accelerator (G) is preferably 0.001 to 20 parts by mass, more preferably 0.005 to 10 parts by mass, and even more preferably 0.025 to 5 parts by mass, per 100 parts by mass of the total polymerizable monomers (B), from the viewpoints of curability and storage stability. In another embodiment, when the polymerizable monomer (B) contains a polymerizable monomer (B-1) having an acidic group, the chemical polymerization accelerator (G) is preferably at least one selected from the group consisting of a copper compound, an aromatic sulfinic acid and its salt, a benzotriazole compound, a benzimidazole compound, a bromide, an ascorbic acid compound, and a sulfur-containing reducing inorganic compound. In the above embodiment, the content of the chemical polymerization accelerator (G) is preferably 0.001 to 40 parts by mass, more preferably 0.005 to 20 parts by mass, and even more preferably 0.025 to 10 parts by mass, relative to 100 parts by mass of the total of the polymerizable monomers (B), from the viewpoints of curability and storage stability.

[0113] The fourth period transition metal compound may be any of a vanadium compound, a copper compound, and a fourth period transition metal compound other than vanadium and copper (hereinafter, simply referred to as "other fourth period transition metal compounds"). In an embodiment, the chemical polymerization accelerator (G) is preferably a vanadium compound or a copper compound from the viewpoint of the polymerization promoting effect.

[0114] Examples of vanadium compounds include vanadyl acetylacetonate(IV), vanadyl stearate, vanadium naphthenate, vanadium benzoylacetonate, vanadyl oxalate, bis(maltolate)oxovanadium(IV), oxobis(1-phenyl-1,3-butanedionato)vanadium(IV), vanadium(V) oxytriisopropoxide, ammonium metavanadate(V), sodium metavanadate(V), vanadium pentoxide, divanadium(IV) tetroxide, and vanadyl(IV) sulfate. Among these, vanadyl acetylacetonate(IV) and bis(maltolate)oxovanadium(IV) are preferred, with vanadyl acetylacetonate(IV) being more preferred, from the viewpoint of solubility in solvents.

[0115] From the viewpoint of hardening property, the content of the vanadium compound is preferably 0.005 to 1 part by mass per 100 parts by mass of the total of the polymerizable monomers (B) in the dental composition of the present invention.

[0116] Examples of copper compounds are preferably compounds soluble in radically polymerizable monomers. Examples of copper compounds include copper carboxylate, copper β-diketone, copper β-ketoester, copper alkoxide, copper dithiocarbamate, and salts of copper and inorganic acids. Examples of copper carboxylates include copper acetate, copper isobutyrate, copper gluconate, copper citrate, copper phthalate, copper tartrate, copper oleate, copper octylate, copper octenoate, copper naphthenate, copper methacrylate, and copper 4-cyclohexylbutyrate. Examples of copper β-diketones include copper acetylacetone, copper trifluoroacetylacetone, copper hexafluoroacetylacetone, copper 2,2,6,6-tetramethyl-3,5-heptanedionato, and copper benzoylacetone. Examples of copper β-ketoesters include copper acetoacetate. Examples of copper alkoxides include copper methoxide, copper ethoxide, copper isopropoxide, copper 2-(2-butoxyethoxy)ethoxide, and copper 2-(2-methoxyethoxy)ethoxide. Examples of copper dithiocarbamates include copper dimethyldithiocarbamate. Examples of salts of copper with inorganic acids include copper nitrate and copper chloride. Among these, from the viewpoints of solubility and reactivity with the polymerizable monomer (B), copper carboxylate, β-diketone copper, and β-ketoester copper are preferred, and copper acetate and copper acetylacetonate are more preferred.

[0117] From the viewpoint of curability, the content of the copper compound is preferably 0.000005 to 1 part by mass, more preferably 0.00001 to 0.5 parts by mass, and even more preferably 0.0001 to 0.1 parts by mass, relative to 100 parts by mass of the total of the polymerizable monomers (B) in the dental composition of the present invention.

[0118] Other examples of fourth-row transition metal compounds include scandium isopropoxide, iron (III) ethoxide, titanium methoxide, titanium ethoxide, titanium isopropoxide, titanium butoxide, titanium hydroxide, and titanium fluoride.

[0119] Among the above-mentioned fourth period transition metal compounds, vanadyl acetylacetonate(IV) and bis(maltolato)oxovanadium(IV) are preferred, with vanadyl acetylacetonate(IV) being more preferred, from the viewpoint of their high polymerization-promoting effect.

[0120] Examples of transition metal compounds other than those of the fourth period include strontium carbonate, strontium hydroxide, strontium ethoxide, tin (II) methoxide, indium ethoxide, actinium ethoxide, yttrium isopropoxide, lanthanum methoxide, lanthanum ethoxide, lanthanum isopropoxide, lanthanum butoxide, lanthanum hydroxide, lanthanum carbonate, lanthanum fluoride, cerium isopropoxide, praseodymium isopropoxide, promethium isopropoxide, neodymium isopropoxide, and sulfur dioxide. Examples of the isopropoxide include marium isopropoxide, europium isopropoxide, gadolinium isopropoxide, terbium ethoxide, terbium methoxide, dysprosium isopropoxide, holmium isopropoxide, erbium isopropoxide, thulium isopropoxide, ytterbium isopropoxide, zirconium ethoxide, zirconium isopropoxide, zirconium butoxide, tungsten(IV) methoxide, tungsten(IV) isopropoxide, and tungsten(IV) butoxide.

[0121] Examples of the thiourea compound include thiourea, methylthiourea, ethylthiourea, ethylenethiourea, N,N'-dimethylthiourea, N,N'-diethylthiourea, N,N'-di-n-propylthiourea, N,N'-dicyclohexylthiourea, trimethylthiourea, triethylthiourea, tri-n-propylthiourea, tricyclohexylthiourea, tetramethylthiourea, tetraethylthiourea, tetra-n-propylthiourea, tetracyclohexylthiourea, 1-(2-pyridyl)-2-thiourea, (6-methyl-pyridin-2-yl)thiourea, 4,4-dimethylethylenethiourea, etc. Among these, 1-(2-pyridyl)-2-thiourea, (6-methyl-pyridin-2-yl)thiourea, and 4,4-dimethylethylenethiourea are preferred from the viewpoints of solubility in solvents and storage stability.

[0122] Examples of tin compounds include di-n-butyltin dimaleate, di-n-octyltin dimaleate, di-n-octyltin dilaurate, di-n-butyltin dilaurate, etc. Particularly suitable tin compounds are di-n-octyltin dilaurate and di-n-butyltin dilaurate.

[0123] Examples of aromatic sulfinic acids and salts thereof include benzenesulfinic acid, p-toluenesulfinic acid, o-toluenesulfinic acid, ethylbenzenesulfinic acid, decylbenzenesulfinic acid, dodecylbenzenesulfinic acid, 2,4,6-trimethylbenzenesulfinic acid, 2,4,6-triisopropylbenzenesulfinic acid, chlorobenzenesulfinic acid, naphthalenesulfinic acid, and their lithium, sodium, potassium, rubidium, cesium, magnesium, calcium, strontium, iron, zinc, ammonium, tetramethylammonium, and tetraethylammonium salts. Among these, from the viewpoint of the polymerizability and storage stability of the composition, the lithium, sodium, potassium, magnesium, and calcium salts of 2,4,6-trimethylbenzenesulfinic acid and 2,4,6-triisopropylbenzenesulfinic acid are preferred, and the lithium, sodium, potassium, magnesium, and calcium salts of 2,4,6-triisopropylbenzenesulfinic acid are more preferred.

[0124] Preferably, at least a portion of the aromatic sulfinic acid and its salt are dispersed in the composition in powder form. Dispersing the aromatic sulfinic acid and its salt in powder form allows the dental composition of the present invention to ensure a longer operating time. Furthermore, when applied to a wet body such as a tooth, the aromatic sulfinic acid and its salt dissolve in water on the wet body surface, further enhancing polymerization at the adhesive interface and within the resin-impregnated layer. When the aromatic sulfinic acid and its salt are dispersed in powder form, the aromatic sulfinic acid and its salt preferably have a solubility in water at room temperature (25°C) of 1 mg / 100 mL or more. Having such a solubility of 1 mg / 100 mL or more facilitates sufficient dissolution of the aromatic sulfinic acid and its salt in water at the adhesive interface when the dental composition of the present invention is applied to a wet body, thereby enhancing the effect of dispersion in powder form. Furthermore, since aromatic sulfinic acids and salts thereof are less likely to settle, the average particle size is preferably 500 μm or less, more preferably 100 μm or less, and even more preferably 50 μm or less. Furthermore, from the viewpoint of preventing the specific surface area of ​​the powder from becoming excessively large and making it easier to maintain good handleability of the dental composition, the average particle size is preferably 0.01 μm or more. That is, when dispersed as a powder, the average particle size is preferably in the range of 0.01 to 500 μm, more preferably 0.01 to 100 μm. The average particle size can be measured in the same manner as the average particle size of the filler (E) described above.

[0125] When aromatic sulfinic acid and its salts are dispersed in powder form, the shape thereof may be, but is not particularly limited to, various shapes such as spherical, needle-like, plate-like, crushed, etc. Aromatic sulfinic acid salts can be prepared into fine powder by conventionally known methods such as pulverization and freeze-drying.

[0126] From the viewpoints of working time and adhesiveness, the content of aromatic sulfinic acid and its salt is preferably 0.1 to 5 parts by mass, more preferably 0.2 to 4 parts by mass, and even more preferably 0.5 to 3 parts by mass, relative to 100 parts by mass of the total of the polymerizable monomers (B) in the adhesive composition of the present invention. If the content is less than 0.1 part by mass, adhesiveness may decrease, and if it exceeds 5 parts by mass, working time may become shorter.

[0127] Examples of bromides include zinc bromide, potassium bromide, sodium bromide, calcium bromide, indium bromide, ammonium bromide, tetrabutylammonium bromide, etc. Among these, zinc bromide, ammonium bromide, and tetrabutylammonium bromide are particularly preferred.

[0128] Examples of borate compounds include arylborate compounds having 1 to 4 aryl groups in one molecule (e.g., tetraphenylboron, tetrakis(p-chlorophenyl)boron, etc.) and salts thereof. Examples of barbituric acid compounds include barbituric acid, 5-butylbarbituric acid, 1,3,5-trimethylbarbituric acid, 1-cyclohexyl-5-ethylbarbituric acid, 1-benzyl-5-phenylbarbituric acid, and salts thereof.

[0129] Examples of ascorbic acid compounds include salts, esters, and ethers of ascorbic acid. Among these, salts and esters of ascorbic acid are preferred.

[0130] Examples of salts of ascorbic acid include sodium L-ascorbate, calcium L-ascorbate, potassium ascorbate, and stereoisomers thereof (e.g., sodium isoascorbate, etc.), etc. Among these, sodium L-ascorbate is preferred.

[0131] Esters of ascorbic acid include those formed by reacting one or more hydroxy groups of ascorbic acid with a carboxylic acid. Suitable examples of the carboxylic acid include fatty acids such as saturated or unsaturated fatty acids having 6 to 30 carbon atoms, such as caprylic acid, capric acid, lauric acid, myristic acid, palmitic acid, stearic acid, arachidic acid, behenic acid, lignoceric acid, cerotic acid, myristoleic acid, palmitoleic acid, sapienic acid, oleic acid, elaidic acid, vaccenic acid, linoleic acid, linoleelaidic acid, α-linolenic acid, arachidonic acid, eicosapentaenoic acid, erucic acid, and docosahexaenoic acid. The number of carbon atoms in the fatty acid is preferably 10 to 28, more preferably 12 to 26, and even more preferably 14 to 24. Among these, esters of stearic acid and ascorbic acid, and esters of palmitic acid and ascorbic acid (ascorbyl palmitate) are particularly preferred.

[0132] Examples of the ethers of ascorbic acid include ethyl ascorbate and cetyl ascorbate.

[0133] Examples of reducing inorganic compounds containing sulfur include sulfites, bisulfites, pyrosulfites, thiosulfates, thionates, and dithionites, and among these, sulfites and bisulfites are preferred.Specific examples of reducing inorganic compounds containing sulfur include sodium sulfite, potassium sulfite, calcium sulfite, ammonium sulfite, sodium hydrogen sulfite, and potassium hydrogen sulfite.

[0134] Preferably, at least a portion of the sulfur-containing reducing inorganic compound is dispersed in the composition in powder form. Dispersing the sulfur-containing reducing inorganic compound in powder form allows the dental composition of the present invention to have a longer operating time. Furthermore, when applied to a tooth, the sulfur-containing reducing inorganic compound dissolves in water on the tooth surface, further enhancing polymerization at the adhesive interface and within the resin-impregnated layer. When the sulfur-containing reducing inorganic compound is dispersed in powder form, the sulfur-containing reducing inorganic compound preferably has a solubility in water at room temperature (25°C) of 1 mg / 100 mL or more. Having a solubility of 1 mg / 100 mL or more allows the sulfur-containing reducing inorganic compound to dissolve sufficiently in water at the adhesive interface when the dental composition of the present invention is applied to a tooth, thereby facilitating the powder dispersion effect. Furthermore, the sulfur-containing reducing inorganic compound preferably has an average particle size of 500 μm or less, more preferably 100 μm or less, and even more preferably 50 μm or less, in order to reduce sedimentation. In addition, from the viewpoint of preventing the specific surface area of ​​the powder from becoming too large and facilitating the easy handling of the dental composition, the average particle size is preferably 0.01 μm or more. That is, when dispersed as a powder, the average particle size is preferably in the range of 0.01 to 500 μm, more preferably in the range of 0.01 to 100 μm. The average particle size can be measured in the same manner as the average particle size of the filler (E) described above.

[0135] When the sulfur-containing reducing inorganic compound is dispersed in the form of a powder, the shape of the powder may be, but is not particularly limited to, various shapes such as spherical, needle-like, plate-like, crushed, etc. The sulfur-containing reducing inorganic compound can be prepared into a fine powder by a conventionally known method such as a pulverization method or a freeze-drying method.

[0136] Furthermore, the dental composition of the present invention may contain a fluoride ion-releasing substance for the purpose of imparting acid resistance to tooth structure. The fluoride ion-releasing substance may be used alone or in combination of two or more. Examples of the fluoride ion-releasing substance include fluoride ion-releasing polymers such as copolymers of methyl methacrylate and methacrylic acid fluoride; fluoride ion-releasing substances such as cetylamine hydrofluoride; and inorganic fillers such as fluoroaluminosilicate glass, sodium fluoride, potassium fluoride, sodium monofluorophosphate, lithium fluoride, and ytterbium fluoride.

[0137] The dental composition of the present invention may contain additives such as a crosslinker, a silanol condensation catalyst, a stabilizer (polymerization inhibitor), a colorant (dye, pigment), and a fluorescent agent. The additives may be used alone or in combination. Examples of crosslinkers and silanol condensation catalysts that can be used include those described in International Publication No. 2019 / 004391. Examples of polymerization inhibitors include hydroquinone, hydroquinone monomethyl ether, dibutyl hydroquinone, dibutyl hydroquinone monomethyl ether, t-butylcatechol, 2-t-butyl-4,6-dimethylphenol, 2,6-di-t-butyl-4-methylphenol, and 2,6-di-t-butylphenol. In addition, antibacterial substances such as cetylpyridinium chloride, benzalkonium chloride, (meth)acryloyloxydodecylpyridinium bromide, (meth)acryloyloxyhexadecylpyridinium chloride, (meth)acryloyloxydecylammonium chloride, triclosan, etc. may be blended in. One type of antibacterial substance may be used alone, or two or more types may be used in combination.

[0138] The dental composition of the present invention is not particularly limited and may be a one-component or two-component type. In a preferred embodiment, from the viewpoint of operability, the dental composition of the present invention is a one-component type dental composition.

[0139] The dental composition of the present invention may contain a solvent (water, organic solvent). In a preferred embodiment, the content of the solvent (water, organic solvent) in the dental composition of the present invention is preferably 0.1% by mass or more, more preferably 1.0% by mass or more, and even more preferably 5.0% by mass or more. Furthermore, the content of the solvent (water, organic solvent) is preferably 50% by mass or less, more preferably 45% by mass or less, and even more preferably 40% by mass or less.

[0140] Furthermore, when the dental composition of the present invention is used as a dental composite resin, etc., it is preferable that the dental composition of the present invention does not contain a solvent (water, organic solvent). In another preferred embodiment, the content of the solvent (water, organic solvent) in the dental composition of the present invention is preferably less than 5.0% by mass, more preferably less than 1.0% by mass, even more preferably less than 0.5% by mass, particularly preferably less than 0.1% by mass, and most preferably less than 0.01% by mass.

[0141] The dental composition of the present invention can be produced, for example, by mixing all ingredients other than the powdery ingredients (such as the filler (E)) to obtain a solution, and then adding the powdery ingredients.

[0142] The present invention includes embodiments in which all or part of the above configurations are combined in various ways within the scope of the technical concept of the present invention, as long as the effects of the present invention are achieved.

[0143] The present invention will now be described in more detail with reference to examples, but the present invention is not limited to these examples, and many modifications can be made by those skilled in the art within the scope of the technical concept of the present invention. The abbreviations and symbols used below are as follows:

[0144] [Ultraviolet absorber (A)] T1: bisethylhexyloxyphenol methoxyphenyl triazine T2: 2-[4,6-bis(biphenyl-4-yl)-1,3,5-triazin-2-yl]-5-[(2-ethylhexyl)oxy]phenol

[0145] [Ultraviolet absorbers other than ultraviolet absorber (A)] T3: 2,4,6-tris[4-(hexyloxy)-2-hydroxy-3-methylphenyl]-1,3,5-triazine T4: 2,4-bis(2,4-dimethylphenyl)-6-(2-hydroxy-4-n-octyloxyphenyl)-1,3,5-triazine T5: 2-(2-hydroxy-4-methoxyphenyl)-4,6-diphenyl-1,3,5-triazine T6: 2,4,6-tri([1,1'-biphenyl]-4-yl)-1,3,5-triazine B1: 2-(3-tert-butyl-2-hydroxy-5-methylphenyl)-5-chloro-2H-benzotriazole B2: 2-(2H-benzotriazol-2-yl)-4-methyl-6-dodecylphenol O1: 2,2'-(1,4-phenylene)bis(4H-3,1-benzoxazin-4-one) O2: 2-ethylhexyl 4-methoxycinnamate

[0146] [Polymerizable Monomer (B-1) Having an Acidic Group] MDP: 10-methacryloyloxydecyl dihydrogen phosphate

[0147] [Polymerizable monomer (B-2) having no acidic group] UDMA: 2,2,4-trimethylhexamethylenebis(2-carbamoyloxyethyl)dimethacrylate HEMA: 2-hydroxyethyl methacrylate Bis-GMA: 2,2-bis[4-(2-hydroxy-3-methacryloyloxypropoxy)phenyl]propane 3G: triethylene glycol dimethacrylate NPG: neopentyl glycol dimethacrylate D-2.6E: 2,2-bis(4-methacryloyloxypolyethoxyphenyl)propane (average number of moles of ethoxy groups added: 2.6) DEAA: N,N-diethylacrylamide MAEA: N-methacryloyloxyethylacrylamide THF-MA: tetrahydrofurfuryl methacrylate UN7600: urethane acrylate (manufactured by Negami Chemical Industrial Co., Ltd., weight average molecular weight (Mw): 11,500, number of polymerizable groups: 2)

[0148] [Photopolymerization initiator (C)] CQ: dl-camphorquinone BAPO: bis(2,4,6-trimethylbenzoyl)phenylphosphine oxide BAPO-ONa: sodium bis(2,4,6-trimethylbenzoyl)phosphinate TMDPO: 2,4,6-trimethylbenzoyldiphenylphosphine oxide

[0149] [Polymerization accelerator (D)] DABE: ethyl 4-(N,N-dimethylamino)benzoate DEPT: N,N-bis(2-hydroxyethyl)-p-toluidine

[0150] [Filler (E)] R972: dimethylsilylated silica, "Aerosil (registered trademark) R972", average primary particle diameter: 16 nm, manufactured by Nippon Aerosil Co., Ltd. Ar380: hydrophilic fumed silica, "Aerosil (registered trademark) 380", average primary particle diameter: 7 nm, manufactured by Nippon Aerosil Co., Ltd. Filler 1: silica, average particle diameter: 2 μm, "Silica Microbead P-500KN", manufactured by JGC Catalysts and Chemicals Co., Ltd. Filler 2: barium glass (trade name: GM27884, average primary particle diameter 0.18 μm, manufactured by Schott Co., Ltd.) 100 parts by mass, 11 parts by mass of 3-methacryloyloxypropyltrimethoxysilane, and 500 mL of 0.5% acetic acid aqueous solution were placed in a three-necked flask and stirred for 2 hours under ultrasonic dispersion at room temperature. After removing water by freeze-drying, the surface-treated BaO filler was prepared by heat treatment at 90 ° C. for 3 hours. This was used as Filler 2. Filler 3: Silica powder (manufactured by Nichitsu Corporation, product name: Hi-Silica) was pulverized in a dry ball mill (Φ10 mm alumina balls) to obtain pulverized silica powder. The average particle size of the obtained pulverized silica powder was measured on a volume basis using a laser diffraction particle size distribution analyzer (model "SALD-2300", manufactured by Shimadzu Corporation) and was found to be 2.2 μm. 100 g of this pulverized silica powder, 4 g of γ-methacryloyloxypropyltrimethoxysilane, and 200 mL of aqueous acetic acid solution were placed in a three-necked flask and stirred for 2 hours under ultrasonic dispersion at room temperature. After removing water by freeze-drying, the mixture was heat-treated at 90°C for 3 hours to produce a filler. This was used as Filler 3. Filler 4: 100 g of Ar130 (hydrophilic fumed silica, ultrafine particle silica "Aerosil (registered trademark) 130", average particle size: 16 nm, manufactured by Nippon Aerosil Co., Ltd.), 30 g of 3-methacryloyloxypropyltrimethoxysilane, and 200 mL of 0.3 mass% acetic acid aqueous solution were placed in a three-necked flask and stirred for 2 hours under ultrasonic dispersion at room temperature. After removing water by freeze-drying, the mixture was heat-treated at 90°C for 3 hours to produce surface-treated SiO2-treated silica. This was used as Filler 4.Filler 5: Commercially available surface-treated SiO2-coated YbF3 (SG-YBF100WSCMP10, average particle size of primary particles: 110 nm, average particle size of secondary particles: 1.2 μm, refractive index: 1.53, manufactured by Sukgyung AT) was used as Filler 5.

[0151] [Others] BHT: 2,6-di-t-butyl-4-methylphenol (polymerization inhibitor)

[0152] Examples 1-1 to 1-8, 2-1 to 2-8, 3-1 to 3-6, 4-1 to 4-5, and Comparative Examples 1-1 to 1-9, 2-1 to 2-9, 3-1 to 3-2, 4-1 to 4-2: Mixtures having the compositions shown in Tables 2 to 5 were used for evaluation as dental compositions. Specifically, for the dental compositions, the dental bonding materials (Tables 2 and 3) were prepared by mixing all components except the filler and solvent (water, organic solvent), then adding the filler and mixing, followed by adding the solvent (water, organic solvent) and mixing. The dental composite resins (Tables 4 and 5) were prepared by mixing all components except the filler, then adding the filler and mixing. The resulting dental compositions were tested using the methods described below. The results are shown in Tables 2 to 5. Furthermore, the solubility and maximum absorption wavelength of the ultraviolet absorbers in hydrophilic polymerizable monomers were measured using the methods described below. The results are shown in Table 1.

[0153] [Measurement of maximum absorption wavelength] The ultraviolet absorber was dissolved in ethyl acetate as a solvent to a concentration of 3×10 -5 A solution of 100 mol / L was prepared, and using a quartz cell with an optical path length of 10 mm, measurements were made in the wavelength range of 250 nm to 500 nm with a spectrophotometer (product name "UH5200", manufactured by Hitachi High-Technologies Corporation), and the maximum absorption wavelength was measured (arithmetic mean value of n = 2).

[0154] [Solubility in Hydrophilic Polymerizable Monomer] The solubility of the UV absorber in the hydrophilic polymerizable monomer was evaluated by the following method. 0.05 parts by mass of the UV absorber was added to 100 parts by mass of 2-hydroxyethyl methacrylate (HEMA) as the hydrophilic polymerizable monomer, and the mixture was stirred using a stirrer at 1000 rpm and 25°C. After stirring for 1 hour, the presence or absence of dissolution was confirmed visually. If the absorber dissolved, an additional 0.01 parts by mass was added, and the addition was continued until the absorber no longer dissolved after stirring for 1 hour. If the absorber did not dissolve, the mixture was stirred for 24 hours, and the presence or absence of dissolution was confirmed visually. If the absorber dissolved, an additional 0.01 parts by mass was added, and the addition was continued until the absorber no longer dissolved after stirring for 24 hours. The value immediately before the absorber no longer dissolved was calculated as the solubility in the hydrophilic polymerizable monomer (arithmetic mean value of n = 2).

[0155] [Solubility] Dental compositions of Examples and Comparative Examples were prepared without the solvent (water and ethanol) and the ultraviolet absorbers (ultraviolet absorber (A) and ultraviolet absorbers other than ultraviolet absorber (A)), and the ultraviolet absorbers in the corresponding amounts of Examples and Comparative Examples were added thereto, followed by stirring using a stirrer at a rotation speed of 1000 rpm and at 25°C for 24 hours. For example, in Example 1-1, a dental composition of 99.74 parts by mass was prepared, and 0.26 parts by mass of T1 was added as the ultraviolet absorber (A), followed by measurement. The dissolution of the added ultraviolet absorber was visually confirmed, and those with no residual residue were rated as "A," and those with residual residue were rated as "B."

[0156] [Unpolymerized Thickness] As an index of photocurability, the unpolymerized thickness was evaluated by the following method. A polyester film was placed on a glass slide, and a 1 mm thick Teflon (registered trademark) mold with a 5 mm diameter hole was placed on top of it. The dental composition prepared above was filled, and the mass was measured (X) [g]. Light was irradiated for 10 seconds using a dental polymerization light irradiator (trade name "Pencure 2000", manufactured by Morita Corporation). Thereafter, the uncured portion was wiped off with a JK Wiper (registered trademark) (manufactured by Nippon Paper Crecia Co., Ltd.), and the mass was measured (Y) [g]. The unpolymerized thickness was calculated using the following formula (arithmetic mean value for n = 5): Unpolymerized Thickness (μm) = ((X) - (Y)) / Specific Gravity [g / mm3 ]÷Area [mm 2 ]×1000

[0157] [8000 Lux Ambient Light Stability] Under an LED-equipped operating light (trade name "Lunaview EL," manufactured by Morita Corporation), the height and light intensity were adjusted to achieve an illuminance of 8000 lux. For dental bonding materials, a dental mixing dish (manufactured by Kuraray Noritake Dental Co., Ltd., product number "#912(TB)") was placed and one drop of sample (e.g., approximately 0.02 g of the composition of Example 2-1) was dropped onto it. The sample was exposed to light while measuring the time (1 second to a maximum of 100 seconds). After the appropriate time, the mixing dish containing the dropped sample was removed from the irradiation area and immediately visually inspected using a small brush for the presence or absence of solidification or gelation to determine whether the sample was physically uniform. The time when solidification or gelation first occurred was determined, and the time 1 second before that was considered the time when uniformity was maintained, and the operating time (unit: seconds) was calculated. For dental composite resins, approximately 0.05 g of sample was weighed onto a glass slide. The sample was exposed to light while measuring the time (1 second to a maximum of 100 seconds), and after an appropriate time, the weighed glass slide on which the sample was placed was removed from the irradiation area and immediately inspected visually for solidification or gelation by pressing the glass slide against the sample from above to check whether the sample was physically uniform. The time when solidification or gelation first occurred was identified, and the time 1 second before that was determined to be the time during which uniformity was maintained, and the operating time (unit: seconds) was calculated.

[0158] [27000 lux ambient light stability] The operating margin time (unit: seconds) was determined in the same manner as in [8000 lux ambient light stability], except that the illuminance was set to 27000 lux.

[0159]

[0160]

[0161]

[0162]

[0163]

[0164] As shown in Tables 2 to 5, the dental compositions of the present invention, regardless of whether they were prepared in any of the Examples, had superior ambient light stability under high illuminance compared to the Comparative Examples of similar aspects. Furthermore, the dental compositions of the present invention, regardless of whether they were prepared in any of the Examples, were able to reduce the thickness of the unpolymerized layer and had superior photocurability compared to the Comparative Examples of similar aspects.

[0165] On the other hand, the dental compositions prepared in the comparative examples could not achieve both environmental light stability under high illuminance and photocurability due to differences in the ultraviolet absorbers. For the comparative examples 1-3, 1-6, 1-7, 2-3, 2-6, and 2-7, the solubility of the ultraviolet absorber was "B," so that the physical properties could not be expected, and other measurements were not performed.

[0166] The dental composition of the present invention can be suitably used in the field of dental care as a dental primer, a dental bonding material, or a dental composite resin (such as a dental self-adhesive composite resin), and is particularly suitably used as a dental bonding material.

Claims

1. A dental composition comprising an ultraviolet absorber (A), a polymerizable monomer (B), and a photopolymerization initiator (C), wherein the ultraviolet absorber (A) has the following [I], [II], and [III]: [I] having a triazine skeleton; [II] being soluble in 0.12 parts by mass or more with respect to 100 parts by mass of 2-hydroxyethyl methacrylate; and [III] dissolving the ultraviolet absorber (A) using ethyl acetate as a solvent, preparing a solution with a concentration of 3×10 -5 mol / L, using a quartz cell with an optical path length of 10 mm, and when measuring the wavelength range from 250 nm to 500 nm with a spectrophotometer, having a maximum absorption wavelength in the wavelength range of 310 nm or more and 400 nm or less; and being a compound satisfying the above conditions.

2. The dental composition according to claim 1, wherein the ultraviolet absorber (A) is a triazine-based ultraviolet absorber represented by the following general formula (1). (R 1 represents an alkyl group or an alkoxy group, and R 2 and R 3 each independently represent a hydrogen atom, a hydroxy group, an alkyl group, an alkoxy group, or a halogen atom, and R 4 , R 5 , and R 6 each independently represent a hydrogen atom or an alkyl group, and R 7 , and R 8 each independently represent a hydrogen atom, a hydroxy group, an alkyl group, an alkoxy group, an aryl group, or a halogen atom, and the alkyl groups and alkoxy groups of R 1 to R 8 may have substituents.) 3. The dental composition according to claim 1 or 2, wherein the content of the ultraviolet absorber (A) is 85 parts by mass or more per 100 parts by mass in total of the ultraviolet absorbers.

4. The R of the ultraviolet absorber (A) 1 The dental composition according to claim 2, wherein the R is an alkyl group or an alkoxy group having 1 to 15 carbon atoms.

5. The R of the ultraviolet absorber (A) 1 is a branched alkyl group or alkoxy group having 3 to 15 carbon atoms, and the dental composition according to claim 4.

6. The R of the ultraviolet absorber (A) 1 is a 2-ethylhexyloxy group, and the dental composition according to claim 5.

7. The dental composition according to claim 6, wherein the ultraviolet absorber (A) is bis(ethylhexyl)oxyphenol methoxyphenyl triazine and / or 2-[4,6-bis(biphenyl-4-yl)-1,3,5-triazin-2-yl]-5-[(2-ethylhexyl)oxy]phenol.

8. The dental composition according to claim 1 or 2, wherein the content of the ultraviolet absorber (A) is 0.01 part by mass or more and 1 part by mass or less with respect to 100 parts by mass in total of the polymerizable monomer (B) contained in the dental composition.

9. The dental composition according to claim 1 or 2, wherein the mass ratio (A):(C) of the content of the ultraviolet absorber (A) to the content of the photopolymerization initiator (C) is 1:0.1 to 1:

50.

10. The dental composition according to claim 1 or 2, wherein the photopolymerization initiator (C) is α-diketones and / or (bis)acylphosphine oxides.

11. The dental composition according to claim 10, wherein the content of the photopolymerization initiator (C) is 0.01 part by mass or more and 5 parts by mass or less per 100 parts by mass of the dental composition.

12. The dental composition according to claim 1 or 2, wherein the dental composition is of a single-agent type.

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