Dental hardening composition

Abstract

To provide a dental curable composition that shows an excellent photo-curing depth immediately after its production and retains it even after long-term storage.SOLUTION: A dental curable composition is a compound comprising a polymerizable monomer (A), a photopolymerization initiator (B), and a ligand (C) containing a phosphorus atom. The ligand (C) contains at least one phosphorus atom. In a spectrum obtained by phosphorus-31 nuclear magnetic resonance spectroscopy, a chemical shift falls within a range of -45.0 ppm to -6.0 ppm.SELECTED DRAWING: None

Description

Technical Field

[0001] The present invention relates to a dental hardenable composition that can replace a part or the whole of a natural tooth and is preferably used as a dental filling and restorative material in the field of dental medicine. More specifically, the present invention relates to a dental hardenable composition preferably used as a dental filling and restorative material for repairing deep cavities formed in the molar region or the like.

Background Art

[0002] For the repair and treatment of defective parts of teeth damaged by dental caries, fractures, etc., dental adhesive materials and dental filling and restorative materials are widely used. As dental adhesive materials and dental filling and restorative materials used for tooth repair, resin-based dental hardenable compositions composed of radical polymerizable monomers, polymerization initiators, fillers, etc. are widely used.

[0003] Among resin-based dental hardenable compositions, dental filling and restorative materials are called dental composite resins and are currently the most widely used dental materials as materials for repairing tooth defects and dental caries. As such dental composite resins, dental photo-curable compositions in which a large amount of inorganic filler and a photo-polymerization initiator are blended in a polymerizable monomer are used. For example, after applying a dental adhesive to the cavity of the tooth to be repaired, filling the dental composite resin and shaping it into the shape of the tooth, and then irradiating light using a dedicated light irradiator to polymerize and cure, the tooth is repaired by the formed polymerized cured body. In addition, visible light is used for the above-mentioned photo-curing from the viewpoint of safety to the human body. Therefore, a visible light-curable polymerization initiator is usually used as the photo-polymerization initiator.

[0004] When repairing large cavities having a depth of 3 to 6 mm using dental composite resin, a method (laminated filling method) is usually adopted in which the dental composite resin is filled into the cavity to a thickness of about 1 to 2 mm and the operation of performing polymerization curing by light irradiation is repeated. In the laminated filling method, since the thickness of the dental composite resin layer is thin, each layer can be sufficiently photocured. On the other hand, since there are many operation steps, simplification of the operation has been demanded. On the other hand, in the method of filling dental composite resin into a large cavity at once and polymerizing it by light irradiation (one-shot filling method), since the dental composite resin layer becomes thick, the dental composite resin at the bottom of the cavity far from the light source cannot be sufficiently polymerized and cured, so peeling is likely to occur at the adhesive interface, and problems such as poor prognosis may occur. Therefore, a dental composite resin with a large photocuring depth has been required.

[0005] In order to increase the photocuring depth, it is necessary to increase the polymerization rate of the entire dental composite resin and improve the curability at the site far from the light source. However, radical polymerization, which is mainly used as the curing mode of dental composite resin, is known to be inhibited by the presence of oxygen. The inhibition by oxygen is due to the rapid reaction between the growing radical that generates the peroxy radical and the oxygen molecule, and since it is different from the reactivity toward the carbon-carbon unsaturated double bond, it does not initiate or participate in the photopolymerization reaction. In addition, the inhibition by oxygen results in incomplete photocuring due to premature chain termination, and the photocuring depth may decrease.

[0006] As an attempt to improve such polymerization inhibition of dental composite resin by oxygen, it is disclosed in Non-Patent Document 1 that triphenylphosphine reacts with a peroxy radical to become triphenylphosphine oxide, thereby regenerating highly active radicals and suppressing polymerization inhibition by oxygen. Further, it is disclosed in Patent Document 1 that a tertiary phosphine compound functions as a polymerization accelerator in a free radical polymerizable composition containing monofunctional and polyfunctional (meth)acrylate monomers. Furthermore, it is disclosed in Patent Document 2 that by using an aromatic tertiary phosphine compound in a dental curable composition, the polymerization efficiency or curing rate is improved and the storage stability is enhanced.

Prior Art Documents

Patent Documents

[0007]

Non-Patent Document 1

Patent Document 1

Patent Document 2

Summary of the Invention

Problems to be Solved by the Invention

[0008] However, regarding the polymerizable compositions disclosed in Non-Patent Document 1 and Patent Document 1, no suggestion is made regarding long-term storage stability. When the present inventors evaluated the storage stability of the polymerizable composition, it was found that the photocuring depth decreased under conditions assuming long-term storage. On the other hand, the composition containing the photoinitiator system disclosed in Patent Document 2 is indeed superior in curability compared to the prior art, and the storage stability was good up to two months at room temperature. However, it was found that the photocuring depth of the composition containing the photoinitiator system decreased after storage under severe conditions assuming even longer-term storage. Patent Document 2 does not suggest anything about the photocuring depth when stored for a long time under severe conditions.

[0009] Therefore, an object of the present invention is to provide a dental curable composition that exhibits excellent photocuring depth from immediately after production to after long-term storage.

Means for Solving the Problems

[0010] As a result of intensive studies by the present inventors, a dental curable composition containing a specific triarylphosphine compound having a phosphorus atom with a chemical shift within a specific range by phosphorus-31 nuclear magnetic resonance spectroscopy (hereinafter sometimes abbreviated as " 31 31P-NMR") was found to be capable of achieving the above object, and based on this finding, further studies were repeated to complete the present invention.

[0011] That is, the present invention includes the following inventions. [1] A dental curable composition comprising a polymerizable monomer (A), a photoinitiator (B), and a ligand (C) containing a phosphorus atom, wherein the ligand (C) containing a phosphorus atom has at least one phosphorus atom and has a chemical shift in the range of -45.0 ppm to -6.0 ppm in the spectrum obtained by phosphorus-31 nuclear magnetic resonance spectroscopy. [2] The dental curable composition according to [1], wherein the ligand (C) containing a phosphorus atom is a compound having three or more aromatic rings. [3] The ligand (C) containing the phosphorus atom is at least one compound selected from the group consisting of a compound represented by the following general formula (1), a compound represented by general formula (2), and a compound represented by general formula (3), the dental curable composition according to [1].

Chemical formula

Chemical formula

Chemical formula

Chemical formula

[0012] According to the present invention, a dental curable composition that exhibits excellent photocuring depth from immediately after production to after long-term storage can be obtained. [Modes for Carrying Out the Invention]

[0013] The present invention will be described below with examples. In the following description, substances, conditions, methods, numerical ranges, etc. may be exemplified, but the present invention is not limited to such exemplifications.

[0014] [Polymerizable Monomer (A)] As the polymerizable monomer (A) used in the present invention, known polymerizable monomers can be used without any limitation. The polymerizable monomer (A) can be used alone or as a mixture of two or more.

[0015] Among the above-mentioned polymerizable monomers (A), radical polymerizable monomers are preferably used. Specific examples of the radical polymerizable monomer in the polymerizable monomer (A) include esters such as α-cyanoacrylic acid, (meth)acrylic acid, α-halogenated acrylic acid, crotonic acid, cinnamic acid, sorbic acid, maleic acid, itaconic acid, etc., (meth)acrylamide, (meth)acrylamide derivatives, vinyl esters, vinyl ethers, mono-N-vinyl derivatives, styrene derivatives, and the like. Among these, (meth)acrylate esters and (meth)acrylamide derivatives are preferred, and (meth)acrylate esters are more preferred. In the present invention, the notation (meth)acryl is used in the meaning of including both methacryl and acryl.

[0016] Further, the polymerizable monomer (A) may have an acidic group. By the polymerizable monomer (A) having an acidic group, the dental curable composition of the present invention exhibits good adhesiveness to dentin and the like. The polymerizable monomer (A) having an acidic group has at least one acidic group such as a phosphate group, a phosphonic acid group, a pyrophosphate group, a thiophosphate group, a carboxylic acid group, a sulfonic acid group, etc., and at least one polymerizable group such as an acryloyl group, a methacryloyl group, an acrylamide group, a methacrylamide group, etc.

[0017] Examples of the polymerizable monomers of (meth)acrylate esters and (meth)acrylamide derivatives are shown below.

[0018] (I) Monofunctional (meth)acrylates and monofunctional (meth)acrylamide derivatives Methyl (meth)acrylate, isobutyl (meth)acrylate, benzyl (meth)acrylate, lauryl (meth)acrylate, 2,3-dibromopropyl (meth)acrylate, 2-hydroxyethyl (meth)acrylate, 6-hydroxyhexyl (meth)acrylate, 10-hydroxydecyl (meth)acrylate, propylene glycol mono(meth)acrylate, glycerin mono(meth)acrylate, erythritol mono(meth)acrylate, N-methylol(meth)acrylamide, N-hydroxyethyl(meth)acrylamide, N,N-bis(2-hydroxyethyl)(meth)acrylamide, (meth)acryloyloxydodecylpyridinium bromide, (meth)acryloyloxydodecylpyridinium chloride, (meth)acryloyloxyhexadecylpyridinium chloride, (meth)acryloyloxydodecylammonium chloride, o-phenylphenol (meth)acrylate, m-phenylphenol (meth)acrylate, p-phenylphenol (meth)acrylate, methoxylated-o-phenylphenol (meth)acrylate, methoxylated-m-phenylphenol (meth)acrylate, methoxylated-p-phenylphenol (meth)acrylate, ethoxylated-o-phenylphenol (meth)acrylate, ethoxylated-m-phenylphenol (meth)acrylate, ethoxylated-p-phenylphenol (meth)acrylate, propoxylated-o-phenylphenol (meth)acrylate, propoxylated-m-phenylphenol (meth)acrylate, propoxylated-p-phenylphenol (meth)acrylate, butoxylated-o-phenylphenol (meth)acrylate, butoxylated-m-phenylphenol (meth)acrylate, butoxylated-p-phenylphenol (meth)acrylate, o-phenoxybenzyl (meth)acrylate, m-phenoxybenzyl (meth)acrylate, p-phenoxybenzyl (meth)acrylate, 2-(o-phenoxyphenyl)ethyl (meth)acrylate, 2-(m-phenoxyphenyl)ethyl (meth)acrylate, 2-(p-phenoxyphenyl)ethyl (meth)acrylate, 3-(o-phenoxyphenyl)propyl (meth)acrylate,3-(m-phenoxyphenyl)propyl (meth)acrylate, 3-(p-phenoxyphenyl)propyl (meth)acrylate, 4-(o-phenoxyphenyl)butyl (meth)acrylate, 4-(m-phenoxyphenyl)butyl (meth)acrylate, 4-(p-phenoxyphenyl)butyl (meth)acrylate, 5-(o-phenoxyphenyl)pentyl (meth)acrylate, 5-(m-phenoxyphenyl)pentyl (meth)acrylate, 5-(p-phenoxyphenyl)pentyl (meth)acrylate, 6-(o-phenoxyphenyl)hexyl (meth)acrylate, 6-(m-phenoxyphenyl)hexyl (meth)acrylate, 6-(p-phenoxyphenyl)hexyl (meth)acrylate and the like can be mentioned.

[0019] (II) Difunctional (meth)acrylate 2,2-bis((meth)acryloyloxyphenyl)propane, 2,2-bis[4-(3-acryloyloxy-2-hydroxypropoxy)phenyl]propane, 2,2-bis[4-(3-methacryloyloxy-2-hydroxypropoxy)phenyl]propane (hereinafter sometimes abbreviated as "Bis-GMA"), 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, 2,2-bis(4-(meth)acryloyloxydipropoxyphenyl)propane, 2-(4-(meth)acryloyloxydiethoxyphenyl)-2-(4-(meth)acryloyloxyethoxyphenyl)propane, 2-(4-(meth)acryloyloxydiethoxyphenyl)-2-(4-(meth)acryloyloxytriethoxyphenyl)propane, 2-(4-(meth)acryloyloxydipropoxyphenyl)-2-(4-(meth)acryloyloxytriethoxyphenyl)propane, 2,2-bis(4-(meth)acryloyloxypropoxyphenyl)propane, 2,2-bis(4-(meth)acryloyloxyisopropoxyphenyl)propane, 1,4-bis(2-(meth)acryloyloxyethyl)pyromellitate, erythritol di(meth)acrylate, sorbitol di(meth)acrylate, mannitol di(meth)acrylate, pentaerythritol di(meth)acrylate, dipentaerythritol di(meth)acrylate, glycerol di(meth)acrylate, ethylene glycol di(meth)acrylate, diethylene glycol di(meth)acrylate, triethylene glycol di(meth)acrylate, propylene glycol di(meth)acrylate, butylene glycol di(meth)acrylate, neopentyl glycol di(meth)acrylate, polyethylene glycol di(meth)acrylate, 1,3-Butanediol di(meth)acrylate, 1,5-pentanediol di(meth)acrylate, 1,6-hexanediol di(meth)acrylate, 1,10-decanediol di(meth)acrylate, 2,2,4-trimethylhexamethylene bis(2-carbamoyloxyethyl) dimethacrylate, 1,2-bis(3-methacryloyloxy-2-hydroxypropyloxy)ethane, N-methacryloyloxyethyl acrylamide, N-methacryloyloxypropyl acrylamide, N-methacryloyloxybutyl acrylamide, N-(1-ethyl-(2-methacryloyloxy)ethyl) acrylamide, N-(2-(2-methacryloyloxyethoxy)ethyl) acrylamide and the like can be mentioned.,

[0020] (III) Tri- or higher-functional (meth)acrylates Trimethylolpropane tri(meth)acrylate, trimethylolethane tri(meth)acrylate, tetramethylolmethane tri(meth)acrylate, pentaerythritol tetra(meth)acrylate, dipentaerythritol hexa(meth)acrylate, N,N'-(2,2,4-trimethylhexamethylene)bis[2-(aminocarboxy)propane-1,3-diol]tetramethacrylate, 1,7-diacryloyloxy-2,2,6,6-tetraacryloyloxymethyl-4-oxaheptane and the like can be mentioned.,

[0021] (IV) Acid group-containing (meth)acrylates and (meth)acrylamide derivatives Examples of the polymerizable monomer having a phosphate group include monofunctional (meth)acrylate compounds having a phosphate group such as 2-(meth)acryloyloxyethyl dihydrogen phosphate, 3-(meth)acryloyloxypropyl dihydrogen phosphate, 4-(meth)acryloyloxybutyl dihydrogen phosphate, 5-(meth)acryloyloxypentyl dihydrogen phosphate, 6-(meth)acryloyloxyhexyl dihydrogen phosphate, 7-(meth)acryloyloxyheptyl dihydrogen phosphate, 8-(meth)acryloyloxyoctyl dihydrogen phosphate, 9-(meth)acryloyloxynonyl dihydrogen phosphate, 10-(meth)acryloyloxydecyl dihydrogen phosphate, 11-(meth)acryloyloxyundecyl dihydrogen phosphate, 12-(meth)acryloyloxydodecyl dihydrogen phosphate, 16-(meth)acryloyloxyhexadecyl dihydrogen phosphate, 20-(meth)acryloyloxyeicosyl 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, their acid chlorides, alkali metal salts, ammonium salts, and amine salts;Bifunctional (meth)acrylate compounds having a phosphate group such as bis[2-(meth)acryloyloxyethyl] hydrogen phosphate, bis[4-(meth)acryloyloxybutyl] hydrogen phosphate, bis[6-(meth)acryloyloxyhexyl] hydrogen phosphate, bis[8-(meth)acryloyloxyoctyl] hydrogen phosphate, bis[9-(meth)acryloyloxynonyl] hydrogen phosphate, bis[10-(meth)acryloyloxydecyl] hydrogen phosphate, 1,3-di(meth)acryloyloxypropyldihydrogen phosphate, etc., acid chlorides, alkali metal salts, ammonium salts, and amine salts thereof, etc. may be mentioned.;

[0022] 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 phosphonoacetate, acid chlorides, alkali metal salts, ammonium salts, and amine salts thereof, etc.

[0023] 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, acid chlorides, alkali metal salts, ammonium salts, and amine salts thereof, etc.

[0024] Examples of the polymerizable monomer having a thiophosphoric acid 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, 8-(meth)acryloyloxyoctyl dihydrogen 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)acryloyloxyeicosyl dihydrogen thiophosphate, and their acid chlorides, alkali metal salts, ammonium salts, etc.

[0025] Examples of the polymerizable monomer having a carboxylic acid group include (meth)acrylic acid, 4-[2-[(meth)acryloyloxy]ethoxycarbonyl]phthalic acid, 4-(meth)acryloyloxyethyl trimellitic acid, 4-(meth)acryloyloxybutyloxycarbonyl phthalic acid, 4-(meth)acryloyloxyhexyloxycarbonyl phthalic acid, 4-(meth)acryloyloxyoctyloxycarbonyl phthalic acid, 4-(meth)acryloyloxydecyloxycarbonyl phthalic acid, and their acid anhydrides; 5-(meth)acryloylaminopentyl carboxylic acid, 6-(meth)acryloyloxy-1,1-hexanedicarboxylic acid, 8-(meth)acryloyloxy-1,1-octanedicarboxylic acid, 10-(meth)acryloyloxy-1,1-decanedicarboxylic acid, 11-(meth)acryloyloxy-1,1-undecanedicarboxylic acid, their acid chlorides, alkali metal salts, ammonium salts, and amine salts, etc.

[0026] Examples of the polymerizable monomer having a sulfonic acid group include 2-(meth)acrylamide-2-methylpropanesulfonic acid, 2-sulfoethyl (meth)acrylate, their acid chlorides, alkali metal salts, ammonium salts, and amine salts.

[0027] Among the polymerizable monomers described above, as the polymerizable monomer (A) used in the present invention, from the viewpoints of the refractive index after polymerization and the handleability of the paste, triethylene glycol di(meth)acrylate, neopentyl glycol di(meth)acrylate, 1,6-hexanediol di(meth)acrylate, 1,10-decanediol di(meth)acrylate, 2,2-bis[4-[3-(meth)acryloyloxy-2-hydroxypropoxy]phenyl]propane, 2,2-bis[4-(meth)acryloyloxypolyethoxyphenyl]propane, [2,2,4-trimethylhexamethylene bis(2-carbamoyloxyethyl)] dimethacrylate, N,N'-(2,2,4-trimethylhexamethylene)bis[2-(aminocarboxy)propane-1,3-diol]tetramethacrylate are preferably used.

[0028] [Photopolymerization initiator (B)] As the photopolymerization initiator (B) of the present invention, known polymerization initiators can be used without any limitation. Usually, it is selected in consideration of the polymerizability of the polymerizable monomer and the polymerization conditions.

[0029] Examples of the photopolymerization initiator (B) include redox initiators such as 1,2-diketone / reducing agent, 1,3-diketone / reducing agent, ketal / reducing agent, thioxanthone / reducing agent, acylphosphine oxide-based, bisacylphosphine oxide-based initiators, benzoin alkyl ether, benzyldimethyl ketal, and the like.

[0030] Examples of 1,2-diketones include camphorquinone, benzyl, 2,3-pentanedione, etc. Examples of 1,3-diketones include dibenzoylmethane, benzoylacetone, acetylpropionylmethane, etc. Examples of ketals include benzyldimethylketal, benzyldiethylketal, etc. Examples of thioxanthones include 2-chlorothioxanthone, 2,4-diethylthioxanthone, etc.

[0031] Examples of reducing agents include 4,4’-bis(dimethylamino)benzophenone, etc.; tertiary amines such as 2-(dimethylamino)ethyl methacrylate, N,N-bis[(meth)acryloyloxyethyl]-N-methylamine, ethyl N,N-dimethylaminobenzoate, butyl 4-dimethylaminobenzoate, butoxyethyl 4-dimethylaminobenzoate, N-methyldiethanolamine, 4-dimethylaminobenzophenone, N,N-bis(2-hydroxyethyl)-p-toluidine, dimethylaminophenanthol, etc.; aldehydes such as citronellal, lauryl aldehyde, phthalaldehyde, dimethylaminobenzaldehyde, terephthalaldehyde, etc.; compounds having a thiol group such as 2-mercaptobenzoxazole, decanethiol, 3-mercaptopropyltrimethoxysilane, 4-mercaptoacetophenone, thiosalicylic acid, thio-benzoic acid, etc. Systems of 1,2-diketone / organic peroxide / reducing agent and 1,3-diketone / organic peroxide / reducing agent with an organic peroxide added to these oxidation-reduction systems are also preferably used.

[0032] Examples of the acylphosphine oxide type include 2,4,6-trimethylbenzoyldiphenylphosphine oxide, 2,6-dimethoxybenzoyldiphenylphosphine oxide, 2,6-dichlorobenzoyldiphenylphosphine oxide, 2,3,5,6-tetramethylbenzoyldiphenylphosphine oxide, benzoyldi(2,6-dimethylphenyl)phosphonate, and 2,4,6-trimethylbenzoylethoxyphenylphosphine oxide. Examples of the bisacylphosphine oxide type include bis(2,6-dichlorobenzoyl)phenylphosphine oxide, bis(2,6-dichlorobenzoyl)-2,5-dimethylphenylphosphine oxide, bis(2,6-dichlorobenzoyl)-4-propylphenylphosphine oxide, bis(2,6-dichlorobenzoyl)-1-naphthylphosphine oxide, bis(2,6-dimethoxybenzoyl)phenylphosphine oxide, bis(2,6-dimethoxybenzoyl)-2,4,4-trimethylpentylphosphine oxide, bis(2,6-dimethoxybenzoyl)-2,5-dimethylphenylphosphine oxide, bis(2,4,6-trimethylbenzoyl)phenylphosphine oxide, and the like. Further, these (bis)acylphosphine oxide types may contain a water-soluble substituent. These (bis)acylphosphine oxide type photoinitiators can be used alone or in combination with reducing agents such as various amines, aldehydes, mercaptans, and sulfinates.

[0033] Among the photoinitiators (B), from the viewpoint of excellent availability, it is preferable that the photoinitiator (B) is at least one selected from the group consisting of 1,2-diketones, 1,3-diketones, and phosphine oxides.

[0034] The above photoinitiator (B) can be used alone or in appropriate combination of two or more. The content of the photoinitiator (B) is preferably 0.05 to 10 parts by mass, more preferably 0.1 to 5.0 parts by mass, and particularly preferably 0.2 to 2.5 parts by mass with respect to 100 parts by mass of the total amount of the polymerizable monomer (A).

[0035] [Ligand (C) containing a phosphorus atom] The ligand (C) containing a phosphorus atom of the present invention has at least one phosphorus atom and is a compound having a chemical shift in the range of -45.0 ppm to -6.0 ppm in the spectrum obtained by phosphorus-31 nuclear magnetic resonance spectroscopy. The number of phosphorus atoms may be one or more, and one or two are preferred.

[0036] Since the electron density of the phosphine site in the ligand (C) containing a phosphorus atom of the present invention is low, oxidation of the phosphine site is suppressed, so it is considered that oxidation of the ligand (C) containing a phosphorus atom during storage is suppressed. As a result, during long-term storage, the storage stability of the dental curable composition is excellent. That is, it becomes possible to suppress the decrease in the photocuring depth after long-term storage that occurred in the prior art. On the other hand, when the electron density of the phosphine site decreases excessively, the reactivity with peroxyl radicals decreases, so the ability to suppress oxygen inhibition decreases and the photocuring depth becomes small. Thus, it is considered that the storage stability of the dental curable composition is greatly affected by the electron density of the phosphine site of the ligand (C) containing a phosphorus atom. The electron density of the phosphine site is 31 It can be estimated by ³¹P-NMR. From the viewpoint that both the storage stability and the curability of the dental curable composition are good, the ligand (C) containing a phosphorus atom 31 has a ³¹P-NMR chemical shift of -45.0 ppm to -6.0 ppm, preferably -40.0 ppm to -9.0 ppm, more preferably -35.0 ppm to -12.0 ppm, still more preferably -30.0 ppm to -15.0 ppm, and most preferably -27.5 ppm to -20.0 ppm. 31 For the measurement of ³¹P-NMR, known measuring devices and measuring methods can be used. 31 The ³¹P-NMR chemical shift can be measured, for example, by the measuring method described in the examples below.

[0037] As a certain preferred embodiment, the ligand (C) containing a phosphorus atom is a compound having at least one phosphorus atom, having the chemical shift, and further having three or more aromatic rings, and a dental curable composition is exemplified. In the above embodiment, the number of aromatic rings is preferably 3 to 8, more preferably 3 to 4, and still more preferably 3.

[0038] As another certain preferred embodiment, the ligand (C) containing a phosphorus atom is at least one compound selected from the group consisting of a compound represented by the following general formula (1), a compound represented by general formula (2), and a compound represented by general formula (3), and a dental curable composition is exemplified.

[0039]

Chemical formula

Chemical formula

Chemical formula

Chemical formula

[0040] R1 to R 15Examples of the hydrocarbon group which may have a substituent include an alkyl group, an alkenyl group, an alkynyl group, an aryl group, an alkylaryl group, an arylalkyl group, an alkylarylalkyl group, an alkenylaryl group, etc., and an alkyl group is preferred.

[0041] Also, in the general formula (1), compounds in which all of R1 to R 15 are hydrogen atoms (triphenylphosphine), and compounds in which all of R1 to R 15 are halogen atoms (tris(pentafluorophenyl)phosphine) are excluded.

[0042] The alkyl group which may have a substituent for R1 to R 15 may be linear, branched, or cyclic. The number of carbon atoms of the alkyl group for R1 to R 15 is not particularly limited, preferably 1 to 12, more preferably 1 to 6, still more preferably 1 to 4, and particularly preferably 1 to 3. Examples of the alkyl group for R1 to R 15 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, and a cyclohexyl group. The alkyl group for R1 to R 15 may be unsubstituted.

[0043] Examples of the substituent of the hydrocarbon group for R1 to R 15 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 in each, an amino group, a mercapto group, etc. When the alkyl group for R1 to R 15 has a substituent, specifically, a haloalkyl group such as a trifluoromethyl group can be mentioned.

[0044] R1 to R 15The hydrocarbon group may have -O-, -S-, -NH-, etc. inserted between carbon atoms. For example, R1 to R 15 The hydrocarbon group may be an alkoxyalkyl group, an alkylthioalkyl group, etc. A nitrogen atom, -P(=O)-, etc. may be inserted and it may branch with this as a branching point, and it may contain an oxygen atom, a nitrogen atom, a sulfur atom, and a phosphorus atom in the form of a heterocyclic ring.

[0045] R1 to R 15 The hydrocarbon group which may have the substituent of may contain at least one kind of atom selected from the group consisting of an oxygen atom, a nitrogen atom, a sulfur atom, and a phosphorus atom. The hydrocarbon group may be an aliphatic group or an aromatic group. Further, the hydrocarbon group may be a saturated hydrocarbon group or an unsaturated hydrocarbon group, and a saturated hydrocarbon group is preferred. Further, the hydrocarbon group may have a branched structure or a ring structure.

[0046] R1 to R 15 Examples of the halogen atom of R1 to R include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom.

[0047] R1 to R 15Examples of the polar group include an acid anhydride group, a carboxylic acid group, a carboxylic acid ester group, a carboxylic acid chloride group, a carboxylic acid amide group, a carboxylate group, a sulfonic acid group, a sulfonic acid ester group, a sulfonic acid chloride group, a sulfonic acid amide group, a sulfonate group, an aldehyde group, an epoxy group, a cyano group, an amino group, a monoalkyl-substituted amino group, a dialkyl-substituted amino group, an imide group, an oxazoline group, a nitro group, a carbamoyl group, an acyl group, etc. From the viewpoints of curability and mechanical strength of the cured product, a carboxylic acid group, a carboxylic acid ester group, a carboxylic acid chloride group, a carboxylic acid amide group, a carboxylate group, a sulfonic acid group, a sulfonic acid ester group, a sulfonic acid chloride group, a sulfonic acid amide group, a sulfonate group, an aldehyde group, a cyano group, a nitro group, a carbamoyl group, an acyl group are preferable, a carboxylic acid group, a carboxylic acid ester group, a carboxylic acid chloride group, a carboxylate group, a sulfonic acid group, a sulfonic acid ester group, a sulfonic acid chloride group, a sulfonate group, an aldehyde group, a cyano group, a nitro group, a carbamoyl group, an acyl group are more preferable, and a carboxylic acid group, a carboxylic acid ester group, a carboxylic acid chloride group, a carboxylate group, a sulfonic acid group, a sulfonic acid ester group, a sulfonic acid chloride group, a sulfonate group, a cyano group, a nitro group, a carbamoyl group, an acyl group are even more preferable. Examples of the salts of the carboxylate group and the sulfonate group include alkali metal salts such as lithium, sodium, and potassium; alkaline earth metal salts such as magnesium, calcium, strontium, barium, and radium, etc. R1~R 15 When it is the polar group, the number of the polar groups is preferably 1 to 9, more preferably 1 to 5, and even more preferably 1 to 3.

[0048] R1~R 15 may be the same or different. R1~R 15 For example, a part of them may be the same hydrogen atom, alkyl group or alkoxy group.

[0049] In a certain preferred embodiment, it is preferable that at least one of R1~R 15 is an electron-withdrawing group (d) described later. R1~R 15The total number of the electron-withdrawing groups (d) is not particularly limited as long as it is one or more, and may be two or more, but is preferably nine or less, more preferably eight or less, and even more preferably seven or less.

[0050] R 16 ~R 35 The hydrocarbon group which may have the substituents of ~R 15 is the same as the hydrocarbon group which may have the substituents of R1~R

[0051] Also, in a certain preferred embodiment, in the general formula (2), compounds in which R 16 ~R 35 are all hydrogen atoms, and compounds in which R 16 ~R 35 are all halogen atoms are excluded.

[0052] The divalent aliphatic group which may have the substituents of X1 may be either linear or branched. The number of carbon atoms of the divalent aliphatic group is preferably 1 to 20, more preferably 1 to 16, even more preferably 1 to 12, and particularly preferably 1 to 8. Examples of the divalent aliphatic group include an alkylene group, an alkenylene group, and an alkynylene group, and an alkylene group is preferred. Examples of the alkylene group include a methylene group, an ethylene group, a propylene group, a butylene group, a methylpropylene group, a dimethylpropylene group, a pentamethylene group, a hexamethylene group, a heptamethylene group, an octamethylene group, a nonamethylene group, a decamethylene group, an undecamethylene group, a dodecamethylene group, etc. Examples of the substituents of the divalent aliphatic group of X1 include the same ones as the substituents of the alkyl group of R1~R 15 .

[0053] The hydrocarbon group which may have the substituents of Z1~Z3 is the same as the hydrocarbon group which may have the substituents of R1~R 15 .

[0054] In a certain preferred embodiment, the ligand (C) containing a phosphorus atom is a dental curable composition which is a compound represented by the general formula (1). Further, in another preferred embodiment, the ligand (C) containing a phosphorus atom is each of the compounds represented by the general formula (1), the compound represented by the general formula (2), and the compound represented by the general formula (3). In each compound, at least one of R1 to R 15 in the general formula (1), at least one of R 16 to R 35 in the general formula (2), and at least one of Z1 to Z3 in the general formula (3) is preferably an electron-withdrawing group (d). In organic electronics theory, the electron-withdrawing group (d) is a group that attracts electrons from the substituted atomic group by an inductive effect or a resonance effect. Examples of the electron-withdrawing group (d) include those having a positive value as the substituent constant (σp (para)) of the Hammett rule. The substituent constant (σp (para)) of the Hammett rule can be cited from the 5th revised edition of the Basic Edition of the Chemical Handbook (page II-380).

[0055] Examples of the electron-withdrawing group (d) include, for example, -F (σp: +0.20), -Cl (σp: +0.28), -Br (σp: +0.30), -I (σp: +0.30), -CO2R x (σp: when R x is an ethyl group +0.45), -CONH2 (σp: +0.38), -COR x (σp: when R x is a methyl group +0.49), -CF3 (σp: +0.50), -SO2R x (σp: when R x is a methyl group +0.69), -NO2 (σp: +0.81), -CN (σp: +0.67), etc. R x each independently represents a hydrogen atom, a substituted or unsubstituted aromatic hydrocarbon group having 6 to 30 ring-forming carbon atoms, a substituted or unsubstituted heterocyclic group having 5 to 30 ring-forming atoms, a substituted or unsubstituted alkyl group having 1 to 30 carbon atoms, or a substituted or unsubstituted cycloalkyl group having 1 to 30 carbon atoms.

[0056] As the electron-withdrawing group (d), a halogen atom, a haloalkyl group, a substituted or unsubstituted acyl group, a substituted or unsubstituted ester group, a substituted or unsubstituted amide group, a substituted or unsubstituted sulfonyl group, or a cyano group is preferable from the viewpoint of chemical stability, and a halogen atom or a haloalkyl group is more preferable.

[0057] Examples of the haloalkyl group include a chloromethyl group, a fluoromethyl group, a methyl iodide group, a trifluoromethyl group, a chloroethyl group, a fluoroethyl group, an ethyl iodide group, a chloropropyl group, and the like. Examples of the acyl group include a formyl group, an acetyl group, a propionyl group, a 2-methylpropionyl group, a 2,2-dimethylpropionyl group, a 2-ethylhexayl group, and the like.

[0058] Examples of the monodentate phosphine represented by the general formula (1) include (2-fluorophenyl)diphenylphosphine, (2-chlorophenyl)diphenylphosphine, (2-bromophenyl)diphenylphosphine, (3-fluorophenyl)diphenylphosphine, (3-chlorophenyl)diphenylphosphine, (3-bromophenyl)diphenylphosphine, (4-fluorophenyl)diphenylphosphine, (4-chlorophenyl)diphenylphosphine, (4-bromophenyl)diphenylphosphine, (2,4,6-trifluorophenyl)diphenylphosphine, (2,4,6-trichlorophenyl)diphenylphosphine, (2,4,6-tribromophenyl)diphenylphosphine, (pentafluorophenyl)diphenylphosphine, (pentachlorophenyl)diphenylphosphine, (pentabromophenyl)diphenylphosphine, bis(2-fluorophenyl)phenylphosphine, bis(2-chlorophenyl)phenylphosphine, bis(2-bromophenyl)phenylphosphine, bis(3-fluorophenyl)phenylphosphine, bis(3-chlorophenyl)phenylphosphine, bis(3-bromophenyl)phenylphosphine, bis(4-fluorophenyl)phenylphosphine, bis(4-chlorophenyl)phenylphosphine, bis(4-bromophenyl)phenylphosphine, bis(2,4,6-trifluorophenyl)phenylphosphine, bis(2,4,6-trichlorophenyl)phenylphosphine, bis(2,4,Phosphine compounds such as (6-tribromophenyl)phenylphosphine, bis(pentafluorophenyl)phenylphosphine, bis(pentachlorophenyl)phenylphosphine, bis(pentabromophenyl)phenylphosphine, tris(2-fluorophenyl)phosphine, tris(2-chlorophenyl)phosphine, tris(2-bromophenyl)phosphine, tris(3-fluorophenyl)phosphine, tris(3-chlorophenyl)phosphine, tris(3-bromophenyl)phosphine, tris(4-fluorophenyl)phosphine, tris(4-chlorophenyl)phosphine, tris(4-bromophenyl)phosphine, tris(4-trifluoromethylphenyl)phosphine, tris(4-trichloromethylphenyl)phosphine, tris(4-tribromomethylphenyl)phosphine, tris(2,4,6-trifluorophenyl)phosphine, tris(2,4,6-trichlorophenyl)phosphine, tris(2,4,6-tribromophenyl)phosphine, 2-(diphenylphosphino)benzenesulfonic acid, 3-(diphenylphosphino)benzenesulfonic acid, 4-(diphenylphosphino)benzenesulfonic acid, 2-(diphenylphosphino)benzonitrile, 3-(diphenylphosphino)benzonitrile, 4-(diphenylphosphino)benzonitrile, etc. are included.,

[0059] Examples of the bidentate phosphine ligand represented by the general formula (2) include phosphine compounds such as 1,2-bis[bis(2-fluorophenyl)phosphino]ethane, 1,2-bis[bis(2-chlorophenyl)phosphino]ethane, 1,2-bis[bis(2-bromophenyl)phosphino]ethane, 1,2-bis[bis(3-fluorophenyl)phosphino]ethane, 1,2-bis[bis(3-chlorophenyl)phosphino]ethane, 1,2-bis[bis(3-bromophenyl)phosphino]ethane, 1,2-bis[bis(4-fluorophenyl)phosphino]ethane, 1,2-bis[bis(4-chlorophenyl)phosphino]ethane, 1,2-bis[bis(4-bromophenyl)phosphino]ethane, 1,2-bis[bis(2-trifluoromethylphenyl)phosphino]ethane, 1,2-bis[bis(2-trichloromethylphenyl)phosphino]ethane, 1,2-bis[bis(2-tribromomethylphenyl)phosphino]ethane, 1,2-bis[bis(3-trifluoromethylphenyl)phosphino]ethane, 1,2-bis[bis(3-trichloromethylphenyl)phosphino]ethane, 1,2-bis[bis(3-tribromomethylphenyl)phosphino]ethane, 1,2-bis[bis(4-trifluoromethylphenyl)phosphino]ethane, 1,2-bis[bis(4-trichloromethylphenyl)phosphino]ethane, 1,2-bis[bis(4-tribromomethylphenyl)phosphino]ethane, 1,2-bis[bis(2,4,6-trifluoromethylphenyl)phosphino]ethane, 1,2-bis[bis(2,4,6-trichloromethylphenyl)phosphino]ethane, and 1,2-bis[bis(2,4,6-tribromomethylphenyl)phosphino]ethane.

[0060] Examples of the bidentate phosphine ligand represented by the general formula (3) include (±)-2,2'-bis(di-4-fluorophosphino)-1,1'-binaphthyl, (±)-2,2'-bis(di-4-chlorophosphino)-1,1'-binaphthyl, (±)-2,2'-bis(di-4-bromophosphino)-1,1'-binaphthyl, (±)-2,2'-bis(di-4-trifluoromethylphosphino)-1,1'-binaphthyl, (±)-2,2'-bis(di-4-trichloromethylphosphino)-1,1'-binaphthyl, (±)-2,2'-bis(di-4-tribromomethylphosphino)-1,1'-binaphthyl, and the like.

[0061] Among the ligands (C) containing the phosphorus atom, from the viewpoint of both good storage stability and curability of the dental curable composition, (pentafluorophenyl)diphenylphosphine, (pentachlorophenyl)diphenylphosphine, tris(4-fluorophenyl)phosphine, tris(4-chlorophenyl)phosphine, tris(4-trifluoromethylphenyl)phosphine, and tris(4-trichloromethylphenyl)phosphine are preferred. The ligand (C) containing the phosphorus atom may be used alone or in combination of two or more. Further, the ligand (C) containing the phosphorus atom is used to enhance the photocurability of the dental curable composition of the present invention.

[0062] In the dental curable composition, the content of the ligand (C) containing the phosphorus atom is preferably in the range of 0.05 to 5 parts by mass, more preferably in the range of 0.15 to 3 parts by mass, and even more preferably in the range of 0.25 to 1.5 parts by mass with respect to 100 parts by mass of the total amount of the polymerizable monomer (A). When the content of the ligand (C) containing the phosphorus atom is less than the above range, since the amount of the ligand (C) containing the phosphorus atom is small, the effect of improving the curability at the time immediately after production is small, and there is a possibility that the effect of improving the curability cannot be obtained after storage under severe conditions. On the other hand, when the content of the ligand (C) containing the phosphorus atom is more than the above range, since the amount of the ligand (C) containing the phosphorus atom is large, the effect of inhibiting the polymerization of the polymerizable monomer (A) becomes large and the curability may decrease.

[0063] The dental curable composition of the present invention may contain a filler in order to obtain sufficient workability of the composition, and further sufficient radiopacity and mechanical strength of the cured product, etc.

[0064] As the filler, any filler can be used as long as the effects of the present invention are not impaired, and examples thereof include inorganic fillers, organic fillers, and composite fillers of inorganic fillers and organic fillers. The filler may be blended singly or in combination of two or more. The average particle size of the filler is preferably 0.001 to 10 μm, and more preferably 0.001 to 5 μm.

[0065] Examples of the inorganic filler include amorphous inorganic particles and inorganic ultrafine particles. Examples of the amorphous inorganic particles include various glasses [silica as the main component, and containing oxides of heavy metals, boron, aluminum, etc. as necessary. For example, dental glass powders such as E glass, barium glass (manufactured by Schott, trade names "GM27884", "GM8235", manufactured by ESSTECH, trade names "E2000", "E3000"), lanthanum glass ceramics (manufactured by Schott, trade name "GM31684")], various ceramics, composite oxides such as silica-titania and silica-zirconia, kaolin, clay minerals (such as montmorillonite), mica, ytterbium fluoride, yttrium fluoride, etc. Examples of the inorganic ultrafine particles include inorganic oxide particles such as silica, alumina, titania, zirconia, or composite oxide particles composed of these, and particles such as calcium phosphate, hydroxyapatite, yttrium fluoride, ytterbium fluoride, barium titanate, potassium titanate, etc. Preferably, they are particles of silica, alumina, titania, silica / alumina composite oxide, silica / zirconia composite oxide produced by the flame pyrolysis method. For example, those manufactured by Nippon Aerosil Co., Ltd., trade names "Aerosil (registered trademark) 50", "Aerosil (registered trademark) 130", "Aerosil (registered trademark) 380", "Aerosil (registered trademark) OX50", "Aeroxide (registered trademark) AluC", "Aeroxide (registered trademark) TiO2P25", "VP Zirconium Oxide 3-YSZ", "VP Zirconium Oxide3-YSZPH". In the present invention, when the inorganic filler is surface-treated as described later, the average particle diameter of the inorganic filler means the average particle diameter before the surface treatment.

[0066] The inorganic ultrafine particles can also be suitably used in the form of aggregated particles formed by aggregation of the inorganic ultrafine particles. Usually, commercially available inorganic ultrafine particles exist as aggregates. However, when 10 mg of inorganic ultrafine particle powder is added to 300 mL of water (dispersion medium) with or without adding a surfactant such as sodium hexametaphosphate at 5 mass% or less and dispersed for 30 minutes with an ultrasonic intensity of an output of 40 W and a frequency of 39 kHz, they have only a weak cohesive force to be dispersed to the particle diameter indicated by the manufacturer. However, the aggregated particles in the present invention are those in which particles that are hardly dispersed even under such conditions are strongly aggregated.

[0067] As a method for producing strongly aggregated particles from commercially available inorganic ultrafine particles, in order to further increase the cohesive force, a method of heating to near the temperature just before the inorganic ultrafine particles melt so that the contacted inorganic ultrafine particles are slightly fused is preferably used. Also, in this case, in order to control the shape of the aggregated particles, a form aggregated before heating may be made. Examples of the method include pressurizing the inorganic ultrafine particles in an appropriate container, or once dispersed in a solvent and then removing the solvent by a method such as spray drying.

[0068] Furthermore, as another suitable method for producing aggregates of inorganic ultrafine particles, silica sol, alumina sol, titania sol, zirconia sol, etc. produced by the wet method are used, dried by a method such as freeze drying or spray drying, and heat-treated as necessary, whereby aggregated particles in which the particles are strongly aggregated can be easily obtained. Specific examples of the sol include those manufactured by Nippon Shokubai Co., Ltd., trade name "Seehoster", those manufactured by JGC Catalysts and Chemicals Ltd., trade names "OSCAL", "QUEEN TITANIC", those manufactured by Nissan Chemical Industries, Ltd., trade names "Snowtex", "Alumina sol", "Celnax", "Nano Use", etc. The shape of the inorganic ultrafine particles is not particularly limited and can be appropriately selected and used. Also, aggregates of commercially available inorganic ultrafine particles can be used as they are. Examples thereof include those manufactured by JGC Catalysts and Chemicals Ltd., trade names "Silica Microbead P-500", "Silica Microbead P-1500".

[0069] Examples of organic fillers include polymers such as polymethyl methacrylate, polyethyl methacrylate, polyfunctional methacrylate, polyamide, polystyrene, polyvinyl chloride, chloroprene rubber, nitrile rubber, and styrene-butadiene rubber.

[0070] Examples of composite fillers of inorganic fillers 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.

[0071] In order to improve curability, mechanical strength, and handleability, the filler may be used after being surface-treated in advance with a known surface treatment agent such as a silane coupling agent. Examples of surface treatment agents include silane coupling agents such as methacryloyloxymethyltrimethoxysilane, 2-methacryloyloxyethyltrimethoxysilane, 3-methacryloyloxypropyltrimethoxysilane, 4-methacryloyloxybutyltrimethoxysilane, 5-methacryloyloxypentyltrimethoxysilane, 6-methacryloyloxyhexyltrimethoxysilane, -methacryloyloxyoctyltrimethoxysilane, 9-methacryloyloxynonyltrimethoxysilane, 10-methacryloyloxydecyltrimethoxysilane, 11-methacryloyloxyundecyltrimethoxysilane, 11-methacryloyloxyundecyldichloromethylsilane, 11-methacryloyloxyundecyltrichlorosilane, 11-methacryloyloxyundecyldimethoxymethylsilane, 12-methacryloyloxydodecyltrimethoxysilane, 13-methacryloyloxytributyltrimethoxysilane, etc.

[0072] The average particle diameter (average primary particle diameter) can be determined by the laser diffraction scattering method or by observing the particles with an electron microscope. Specifically, the laser diffraction scattering method is convenient for measuring the particle diameter of particles with an average particle diameter of 0.1 μm or more, and electron microscope observation is convenient for measuring the particle diameter of ultrafine particles with an average particle diameter of less than 0.1 μm. The laser diffraction scattering method can be measured, for example, by a laser diffraction particle size distribution measuring device (SALD-2300, manufactured by Shimadzu Corporation) on a volume basis using an aqueous solution of 0.2% sodium hexametaphosphate as a dispersion medium. For electron microscope observation, a scanning electron microscope (manufactured by Hitachi High-Technologies Corporation, SU3800, S-4000, etc.) can be used. Electron microscope observation can be determined by taking an electron micrograph of the particles and measuring the particle diameters of the particles (200 or more) observed within the unit field of view of the photograph using image analysis type particle size distribution measurement software (Mac-View (manufactured by Mount Tech Co., Ltd.)). At this time, the particle diameter is determined as the arithmetic mean value of the longest length and the shortest length of the particles, and the average primary particle diameter is calculated from the number of particles and their particle diameters.

[0073] The filler content is not particularly limited as long as the effects of the present invention are exhibited. However, it is preferably in the range of 50 to 1000 parts by mass, more preferably in the range of 100 to 500 parts by mass, and even more preferably in the range of 100 to 300 parts by mass with respect to 100 parts by mass of the total amount of the polymerizable monomer (A) of the dental curable composition of the present invention. Within these ranges, sufficient radiopacity or sufficient mechanical strength of the cured product can be obtained, and sufficient paste workability can be obtained.

[0074] The dental curable composition of the present invention may contain, for example, a redox polymerization initiator such as an organic peroxide / amine system, an organic peroxide / amine / sulfinic acid (or its salt) system. When using a redox polymerization initiator, the oxidizing agent and the reducing agent are in a packaged form where they are separately packaged, and it is necessary to mix the two immediately before use. Examples of the oxidizing agent include organic peroxides such as diacyl peroxides, peroxy esters, peroxy carbonates, dialkyl peroxides, peroxy ketals, ketone peroxides, and hydroperoxides. Specifically, examples of diacyl peroxides include benzoyl peroxide, 2,4-dichlorobenzoyl peroxide, m-toluoyl peroxide, lauroyl peroxide, etc. Examples of peroxy esters include t-butyl peroxybenzoate, bis-t-butyl peroxyisophthalate, t-butyl peroxy-2-ethylhexanoate, etc. Examples of peroxy carbonates include t-butyl peroxyisopropyl carbonate. Examples of dialkyl peroxides include dicumyl peroxide, di-t-butyl peroxide, 2,5-dimethyl-2,5-bis(benzoylperoxy)hexane. Examples of peroxy ketals include 1,1-bis(t-butylperoxy)3,3,5-trimethylcyclohexane. Examples of ketone peroxides include methyl ethyl ketone peroxide. Examples of hydroperoxides include t-butyl hydroperoxide. As the reducing agent, usually a tertiary amine is used.Examples of the tertiary amine include N,N-dimethylaniline, N,N-dimethyl-p-toluidine, N,N-dimethyl-m-toluidine, N,N-diethyl-p-toluidine, N,N-dimethyl-3,5-dimethylaniline, N,N-dimethyl-3,4-dimethylaniline, N,N-dimethyl-4-ethylaniline, N,N-dimethyl-4-i-propylaniline, N,N-dimethyl-4-t-butylaniline, N,N-dimethyl-3,5-di-t-butylaniline, N,N-bis(2-hydroxyethyl)-p-toluidine, N,N-bis(2-hydroxyethyl)-3,5-dimethylaniline, N,N-bis(2-hydroxyethyl)-3,4-dimethylaniline, N,N-bis(2-hydroxyethyl)-4-ethylaniline, N,N-bis(2-hydroxyethyl)-4-i-propylaniline, N,N-bis(2-hydroxyethyl)-4-t-butylaniline, N,N-bis(2-hydroxyethyl)-3,5-di-i-propylaniline, N,N-bis(2-hydroxyethyl)-3,5-di-t-butylaniline, ethyl 4-dimethylaminobenzoate, n-butoxyethyl 4-dimethylaminobenzoate, (2-methacryloyloxy)ethyl 4-dimethylaminobenzoate, trimethylamine, triethylamine, N-methyldiethanolamine, N-ethyldiethanolamine, N-n-butyldiethanolamine, N-lauryl diethanolamine, triethanolamine, (2-dimethylamino)ethyl methacrylate, N-methyldiethanolamine dimethacrylate, N-ethyldiethanolamine dimethacrylate, triethanolamine monomethacrylate, triethanolamine dimethacrylate, triethanolamine trimethacrylate, and the like. In addition to the above, redox initiators such as cumene hydroperoxide / thiourea system, ascorbic acid / Cu. 2+ In addition to the redox initiators such as salt system, organic sulfinic acid (or its salt) / amine / inorganic peroxide system, tributylborane, organic sulfinic acid, etc. are also preferably used.

[0075] In the dental curable composition of the present invention, additives such as a polymerization inhibitor, an ultraviolet absorber, a fluorescent agent, and a pigment may be blended in addition to the above-described components.

[0076] Examples of the coincidence inhibitor include, for example, 2,6-di-t-butyl-4-methylphenol, hydroquinone, dibutylhydroquinone, dibutylhydroquinone monomethyl ether, 2,6-di-t-butylphenol, 4-methoxyphenol, etc., and one or more of these may be blended. Examples of the ultraviolet absorber include, for example, triazine-based ultraviolet absorbers, benzotriazole-based ultraviolet absorbers, benzophenone-based ultraviolet absorbers, benzoate-based ultraviolet absorbers, hindered amine-based light stabilizers, etc., and one or more of these may be blended. Examples of the fluorescent agent include, for example, 2-(2-hydroxyphenyl)-4(1H)-quinazolinone, 2-(2-hydroxyphenyl)-4H-3,1-benzoxazin-4-one, N-[2-(4(1H)-quinazolinone-2-yl)phenyl]benzenesulfonamide, N-[2-(4-oxo-1,3-benzoxazin-2-yl)phenyl]benzenesulfonamide, 7-dimethylamino-3-[2-[4-(trifluoromethyl)phenyl]ethenyl]-2H-1,4-benzoxazin-2-one, 7-dimethylamino-3-[2-[2,3,4,5,6-pentafluorophenyl]ethenyl]-2H-1,4-benzoxazin-2-one, 7-dimethylamino-3-[2-[2,4-bis(trifluoromethyl)phenyl]ethenyl]-2H-1,4-benzoxazin-2-one, etc., and one or more of these may be blended. The pigment may be either an inorganic pigment and / or an organic pigment. Examples of the inorganic pigment include, for example, chromates such as lead yellow, zinc yellow, barium yellow; ferrocyanides such as ultramarine blue; sulfides such as vermilion, cadmium yellow, zinc sulfide, cadmium red; sulfates such as barium sulfate, zinc sulfate, strontium sulfate; oxides such as antimony white, zinc white, titanium white, red iron oxide, iron black, chromium oxide; hydroxides such as aluminum hydroxide; silicates such as calcium silicate, ultramarine blue; carbon such as carbon black, graphite, etc.Examples of the organic pigment include nitroso compounds such as naphthol green B and naphthol green Y; nitro pigments such as naphthol yellow S and lysol fast yellow 2G; insoluble azo pigments such as permanent red 4R, brilliant fast scarlet, hansa yellow, and benzidine yellow; poorly soluble azo pigments such as lysol red, lake red C, and lake red D; soluble azo pigments such as brilliant carmine 6B, permanent red F5R, pigment scarlet 3B, and Bordeaux 10B; phthalocyanine pigments such as phthalocyanine blue, phthalocyanine green, and sky blue; basic compounds such as rhodamine lake, malachite green lake, and methyl violet lake; acidic compounds such as peacock blue lake, eosin lake, and quinoline yellow lake, etc. The above pigments may be blended alone or in combination of two or more.

[0077] [Form of the dental curable composition] The dental curable composition of the present invention can be used, for example, in dental composite resins, dental cements, pit and fissure sealants, loose tooth fixatives, orthodontic adhesives, etc. Among them, it is more preferably used as a dental composite resin because of its excellent photocuring depth.

[0078] The dental curable composition of the present invention is not particularly limited as long as it contains a polymerizable monomer (A), a photopolymerization initiator (B), and a ligand (C) containing a phosphorus atom, and can be easily produced by a method known to those skilled in the art in a state according to the application (1 paste state, 2 paste state, powder-liquid state, molded state). When a chemically polymerizable function or a polymerization initiation function having both chemical polymerizability and photopolymerizability is used, the composition containing an oxidizing agent and the composition containing a reducing agent are separately packaged, and it is necessary to mix the two immediately before use.

[0079] The present invention includes embodiments in which the above configurations are variously combined within the technical scope of the present invention as long as the effects of the present invention are achieved.

Examples

[0080] Hereinafter, the present invention will be described in detail with reference to Examples and Comparative Examples, but the present invention is not limited to these Examples. The analysis and evaluation in the following Examples and Comparative Examples were carried out as follows.

[0081] (1) Depth of photocuring In accordance with JIS T 6514:2015 (Composite resin for dental restoration), the depth of photocuring was evaluated. Specifically, it was carried out as follows. The manufactured dental curable composition was filled into a stainless steel mold (thickness 12 mm, diameter 4 mm). The upper and lower surfaces were overlaid and pressure-bonded in the order of film and slide glass, and the glass plate was removed from one side. The film pressure-bonded surface was irradiated with light for 10 seconds using a dental visible light irradiator "Pen Curer 2000" (manufactured by Morita Corporation) to cure it. After removing the cured product from the mold, the uncured portion was wiped off, and the depth of photocuring from the light-irradiated surface was measured using a micrometer (manufactured by Mitutoyo Corporation). Half of the measured value was taken as the depth of photocuring (n = 5), and the average value was calculated. The depth of photocuring is preferably 4.5 mm or more, more preferably 5.0 mm or more, and even more preferably 5.5 mm or more.

[0082] (2) Phosphorus-31 nuclear magnetic resonance spectroscopy ( 31 P-NMR) 31 P-NMR was measured using a nuclear magnetic resonance apparatus manufactured by BRUKER (product name "Ultrashield (registered trademark) 400 Plus") (measurement conditions: 162 MHz). A ligand (C) containing a phosphorus atom or a ligand containing a phosphorus atom other than the ligand (C) was dissolved in chloroform-d to a concentration of 5 mg / mL and measured at 300K. An 85% phosphoric acid solution was used as the internal standard.

[0083] (3) Average particle diameter of inorganic particles The particle size distribution was determined by the laser diffraction scattering method and determined as the volume median particle diameter. The volume median particle diameter means the particle diameter at which the cumulative volume frequency calculated by the volume fraction becomes 50% when calculated from the smaller particle diameter. Measuring instrument: SALD-2300 type (manufactured by Shimadzu Corporation) Analysis software: Light transmission centrifugal sedimentation method Dispersion: 0.2% sodium hexametaphosphate Dispersion conditions: 15 mg of inorganic particles are added to 20 mL of the above dispersion and dispersed with an ultrasonic disperser for 30 minutes to prepare a sample dispersion. Measurement conditions: The sample dispersion is measured to determine the volume median particle diameter and the ratio of the number of particles having a particle diameter of 0.01 to 100 μm.

[0084] <Production example of inorganic particles> 100 g of barium glass "GM27884 NanoFine180 (average particle diameter 0.18 μm)" (manufactured by Shot Co., Ltd.), 11 g of 11-methacryloyloxyundecyltrimethoxysilane, and 200 mL of toluene are placed in a three-necked flask and stirred at room temperature for 2 hours. After distilling off toluene under reduced pressure, vacuum drying is carried out at 40 °C for 16 hours, and further heating is carried out at 90 °C for 3 hours to obtain inorganic particles (e) with an average particle diameter of 0.18 μm provided with a surface treatment layer.

[0085] Details of the compounds used in the examples and comparative examples are as follows. [Polymerizable monomer (A)] D2.6E: 2,2-bis(4-methacryloyloxypolyethoxyphenyl)propane (average number of added moles of ethoxy group: 2.6); manufactured by Shin-Nakamura Chemical Co., Ltd. 3G: Triethylene glycol dimethacrylate; manufactured by Tokyo Chemical Industry Co., Ltd.

[0086] [Photoinitiator (B)] CQ: Camphorquinone; manufactured by Fujifilm Wako Pure Chemical Corporation PDE: Ethyl N,N-dimethylaminobenzoate; manufactured by Fujifilm Wako Pure Chemical Corporation

[0087] [Ligand (C) containing a phosphorus atom] PFPDPP: (Pentafluorophenyl)diphenylphosphine; manufactured by Tokyo Chemical Industry Co., Ltd. TFPP: Tris(4-fluorophenyl)phosphine; manufactured by Tokyo Chemical Industry Co., Ltd. TTFMPP: Tris(4-trifluoromethylphenyl)phosphine; manufactured by FUJIFILM Wako Pure Chemical Corporation TCPP: Tris(4-chlorophenyl)phosphine; manufactured by FUJIFILM Wako Pure Chemical Corporation

[0088] [Phosphorus compound other than ligand (C) containing phosphorus atom] TPP: Triphenylphosphine; manufactured by FUJIFILM Wako Pure Chemical Corporation DPPS: 4-(Diphenylphosphino)styrene; manufactured by Tokyo Chemical Industry Co., Ltd. DPBA: 4-(Diphenylphosphino)benzoic acid; manufactured by Tokyo Chemical Industry Co., Ltd. BPFPP: Bis(pentafluorophenyl)phenylphosphine; manufactured by Tokyo Chemical Industry Co., Ltd. TPFPP: Tris(pentafluorophenyl)phosphine; manufactured by Tokyo Chemical Industry Co., Ltd. [Polymerization inhibitor] BHT: 2,6-Di-t-butyl-4-methylphenol; manufactured by FUJIFILM Wako Pure Chemical Corporation

[0089] <Example 1> 70 parts by mass of D2.6E7, 30 parts by mass of 3G3, 0.2 parts by mass of CQ, 0.3 parts by mass of PDE, 0.1 parts by mass of PFPDPP, and 0.05 parts by mass of BHT were mixed to obtain a polymerizable monomer composition (m-1).

[0090] 7.0 parts by mass of inorganic particles (e) were mixed and kneaded with 3.0 parts by mass of the polymerizable monomer composition (m-1) to make it uniform, and then vacuum degassed to obtain a dental curable composition. The dental curable composition was filled into a storage container consisting of a syringe made of a polyolefin resin (inner diameter 8 mm × length 63 mm) and a cylindrical plunger fitted into the syringe from the rear end side of the syringe, and the photocuring depth immediately after preparation by the above method was measured. The results are shown in Table 1.

[0091] The dental curable composition filled in the syringe container was placed in a forced-air constant temperature thermostat set at 60°C, and the photocuring depth after storage for 4 weeks and 8 weeks by the above method was measured. The results are shown in Table 1.

[0092] <Examples 2 to 11 and Comparative Examples 1 to 6> Except that instead of PFPDPP, the type and content of ligand (C) containing a phosphorus atom or a phosphorus compound other than ligand (C) containing a phosphorus atom, the content of polymerizable monomer (A), and the content of photopolymerization initiator (B) were changed as shown in Table 1, dental curable compositions of each example and comparative example were prepared and evaluated in the same manner as in Example 1. The results are shown in Table 1.

[0093]

Table 1

[0094] As shown in Table 1, the dental curable composition of the present invention could maintain a good photocuring depth not only immediately after preparation but also after long-term storage, as compared with the dental curable composition of the comparative example.

[0095] In Patent Document 2, from the viewpoint of suppressing the coloring of dental compositions, it is considered that the chromophore of the photopolymerization initiator is efficiently destroyed during polymerization, and as a result, the coloring of the initiator system disappears in the polymerized dental composition, so-called "photobleaching" is required. It was thought that a specific aromatic tertiary phosphine compound was excellent in the photobleaching effect, and the destruction of the chromophore during polymerization was considered to increase the photocuring depth of the dental composition. On the other hand, the present invention relates to a phosphorus compound not disclosed in Patent Document 2 31Focusing on the chemical shift of ³¹P-NMR, a ligand (C) containing specific phosphorus atoms not specifically disclosed was selected. By containing the ligand (C) containing a phosphorus atom, the dental curable composition of the present invention suppresses the oxidation of the phosphine moiety because the electron density of the phosphine moiety is low, and can suppress the oxidation of the ligand (C) containing a phosphorus atom during long-term storage, and exhibits excellent photocuring depth from immediately after production to after long-term storage. It was confirmed that the dental curable composition of the present invention can maintain excellent photocuring depth even when stored for a long time under severe conditions, as compared with Comparative Examples 3 and 4 using the compounds specifically disclosed in Patent Document 2. In Patent Document 2, it was considered that if the photobleaching effect is excellent, the photocuring depth can also be increased. However, according to the findings of the present inventors, even a compound having excellent photobleaching effect and the property that the polymerization rate does not decrease after storage for a certain period of time does not necessarily have a correlation with these properties and the photocuring depth particularly when stored for a long time under severe conditions. In the present invention, it has been clarified that by selectively containing a ligand (C) containing specific phosphorus atoms, it is possible to provide a dental curable composition that exhibits excellent photocuring depth from immediately after production to after long-term storage for the first time. Further, in Comparative Examples 5 and 6, since the electron density of the phosphine moiety was too low, the reactivity with peroxyl radicals decreased, and sufficient photocuring depth could not be obtained.

Industrial Applicability

[0096] The dental curable composition of the present invention is suitably used as a material that can replace a part or the whole of natural teeth in the field of dental medicine, and is particularly optimal for dental composite resins.

Claims

1. It contains a polymerizable monomer (A), a photoinitiator (B), and a ligand (C) containing a phosphorus atom, wherein the ligand (C) containing a phosphorus atom has at least one phosphorus atom and has a chemical shift in the range of -45.0 ppm to -6.0 ppm in the spectrum obtained by phosphorus-31 nuclear magnetic resonance spectroscopy, and is a compound, wherein the polymerizable monomer (A) is a radically polymerizable monomer, and the ligand (C) containing a phosphorus atom is at least one compound selected from the group consisting of a compound represented by the following general formula (1), a compound represented by general formula (2), and a compound represented by general formula (3), a dental curable composition. 【Chemical 1】 (R1 to R15 each independently represent a hydrogen atom, a halogen atom, a polar group, or a hydrocarbon group which may have a substituent.) 【Chemical 2】 (R16 to R35 each independently represent a hydrogen atom, a halogen atom, a polar group, or a hydrocarbon group which may have a substituent, and X1 represents a divalent aliphatic group which may have a substituent.) 【Chemical Formula 3】 (Ar each independently represents a group represented by the following general formula (3-a).) 【Chemical Formula 4】 (Z1 to Z3 each independently represent a hydrogen atom, a halogen atom, or a hydrocarbon group which may have a substituent, and at least one of Z1 to Z3 is a hydrogen atom.)

2. In the ligand (C) containing the phosphorus atom, in each of the compound represented by the general formula (1), the compound represented by the general formula (2), and the compound represented by the general formula (3), R in the general formula (1) 1 ~R 15 at least one of, R in the general formula (2) 16 ~R 35 at least one of, and Z in the general formula (3) 1 ~Z 3 at least one of is an electron-withdrawing group (d), the dental curable composition according to claim 1.

3. The dental curable composition according to claim 2, wherein the electron-withdrawing group (d) is at least one selected from the group consisting of a halogen atom, a haloalkyl group, a substituted or unsubstituted acyl group, a substituted or unsubstituted ester group, a substituted or unsubstituted amide group, a substituted or unsubstituted sulfonyl group, and a cyano group.

4. The dental curable composition according to any one of claims 1 to 3, wherein the content of the ligand (C) containing a phosphorus atom is in the range of 0.05 to 5 parts by mass with respect to 100 parts by mass of the total amount of the polymerizable monomer (A).

5. The dental curable composition according to any one of claims 1 to 4, wherein the photoinitiator (B) is at least one selected from the group consisting of 1,2-diketone, 1,3-diketone, and phosphine oxide.

6. A dental composite resin comprising the dental curable composition according to any one of claims 1 to 5.

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