X-ray radiopaque compound and dental adhesive composition

Abstract

To provide an X-ray radiopaque compound that has excellent X-ray radiopacity, suppresses halogen release, and allows for simple synthesis.SOLUTION: An X-ray radiopaque compound includes: a structural moiety A that includes a halogen atom and has an acyclic structure; and a structural moiety B that is derived from a (meth)acrylate.SELECTED DRAWING: None

Description

[Technical field]

[0001] The present invention relates to radiopaque compounds and dental adhesive compositions. [Background technology]

[0002] In the dental field, dental adhesive compositions are required to have X-ray contrast properties in order to prevent misdiagnosis of secondary caries. Generally, compounds derived from polymerizable monomers or polymerizable polymers contained in dental adhesive compositions do not exhibit X-ray contrast properties. Therefore, dental adhesive compositions containing a filler such as barium are widely used for the purpose of imparting X-ray contrast properties to dental adhesive compositions. Since the filler reacts with and inactivates the acidic monomer contained in the dental adhesive composition, in recent years, there has been a demand for dental adhesive compositions that do not use a filler and in which the compound derived from the polymerizable monomer or polymerizable polymer itself is imparted with X-ray contrast properties.

[0003] For example, a brominated polymerizable monomer has been proposed that includes a resin matrix having a specific structure with X-ray contrast properties, a filler matrix in an amount of at least 25% by weight relative to the weight of the dental composition, and an initiator (see, for example, Patent Document 1). [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Special Publication No. 2021-502357 Summary of the Invention [Problem to be solved by the invention]

[0005] However, in conventional dental adhesive compositions including the invention described in Patent Document 1, a halogen having X-ray contrast is bonded to a benzene ring in an aromatic compound contained in the dental adhesive composition, and therefore, due to the structure, the halogen is easily liberated, which is a concern as a problem that X-ray contrast is reduced due to this. In addition, the X-ray contrast compound has a problem that the synthesis route is complicated.

[0006] In view of the problems and concerns of the above-mentioned conventional techniques, the present invention aims to provide an X-ray contrast compound that has excellent X-ray contrast properties, can suppress the release of halogen, and can be easily synthesized. [Means for solving the problem]

[0007] The X-ray contrast compound of the present invention as a means for solving the above problems comprises a structural portion A which contains a halogen atom and has a non-cyclic structure, and a structural portion B which is derived from a (meth)acrylate. Effect of the Invention

[0008] According to the present invention, it is possible to provide an X-ray contrast compound which has excellent X-ray contrast properties, is capable of suppressing the liberation of halogen, and can be easily synthesized. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0009] The present invention will be described in detail below.

[0010] (X-ray contrast compound) The X-ray contrast compound of the present invention contains a structural portion A which contains a halogen atom and is a non-cyclic structure, and a structural portion B derived from a (meth)acrylate, and may contain other structural portions as necessary. The other structural parts can be appropriately selected within a range that does not impair the effects of the present invention.

[0011] In this specification, "structural portion A which contains a halogen atom and is a non-cyclic structure" may be simply referred to as "structural portion A," and "structural portion B derived from (meth)acrylate" may be simply referred to as "structural portion B." In this specification, the "X-ray contrast compound" may be simply referred to as the "compound." As used herein, "(meth)acrylate" refers to either or both of acrylate and methacrylate.

[0012] As described above, the X-ray contrast compound can suppress the release of halogen. In other words, the X-ray contrast compound can suppress the release of halogen and maintain high X-ray contrast. In the present invention, the mechanism by which the release of halogen is suppressed is not clear, but it is presumed to be due to the structural stability of the X-ray contrast compound. In addition, the X-ray contrast compound has high X-ray opacity (the property of blocking X-rays when irradiated with X-rays without allowing them to pass through), which can improve X-ray contrast.

[0013] <Structural part A> The structural portion A is not particularly limited as long as it contains a halogen atom and is a structural portion derived from a non-cyclic structure, and can be appropriately selected depending on the purpose. The non-cyclic structure is not particularly limited as long as it does not have a ring structure and can be appropriately selected depending on the purpose. Examples of the non-cyclic structure include saturated or unsaturated non-cyclic hydrocarbon structures. The non-cyclic structure is preferably a branched chain, and more preferably has a halogen atom in the side chain. In this specification, the "main chain" refers to the longest straight chain in the compound consisting of the structural portion A and the structural portion B, and the "side chain" refers to a molecular chain that is not the main chain. The "main chain" in the structural portion A refers to a molecular chain contained in the main chain of the compound, and the "side chain" in the structural portion A refers to a molecular chain that is not the main chain. In the structural portion A, when the branched chains have the same length, the molecular chain having a halogen atom is the side chain.

[0014] The structural portion A is not particularly limited as long as it contains a halogen atom and has a non-cyclic structure and can be appropriately selected depending on the purpose. From the viewpoint of facilitating the synthesis of the compound, however, those having a hydroxyl group, an isocyanate group, an epoxy group, an amino group, or a carboxyl group are preferable, and those having a hydroxyl group are more preferable.

[0015] <Structural part B> The structural portion B is not particularly limited as long as it is a structural portion derived from a (meth)acrylate and can be appropriately selected depending on the purpose. The (meth)acrylate is not particularly limited and can be appropriately selected depending on the purpose. From the viewpoint of facilitating the synthesis of the compound, however, those having a hydroxyl group, an isocyanate group, an epoxy group, an amino group, or a carboxyl group are preferred, and those having a carboxylic acid group are more preferred.

[0016] The (meth)acrylate having a carboxylic acid group is not particularly limited and can be appropriately selected depending on the purpose. Examples thereof include mono(2-acryloyloxyethyl) succinate and 2-carboxyethyl acrylate.

[0017] The (meth)acrylate may be a properly synthesized product or a commercially available product. Examples of the commercially available (meth)acrylate include mono(2-acryloyloxyethyl) succinate (manufactured by Tokyo Chemical Industry Co., Ltd.) and 2-carboxyethyl acrylate (manufactured by Tokyo Chemical Industry Co., Ltd.).

[0018] The X-ray contrast compound preferably contains at least one selected from the group consisting of a structure represented by the following general formula (1), a structure represented by the following general formula (2), and a structure represented by the following general formula (3).

[0019] [ka] (In the general formula (1), R1 and R2 each independently represent "-H" or "-CH3", X1 and X2 each independently represent "-O-" or "-NH-", and Y1 and Y2 each independently represent a linear or branched hydrocarbon group having from 1 to 20 carbon atoms, which may have an ether bond, an ester bond, and / or an amide bond.)

[0020] [ka] (In the general formula (2), R3 and R4 each independently represent "-H" or "-CH3", X3 and X4 each independently represent "-O-" or "-NH-", and Y3 and Y4 each independently represent a linear or branched hydrocarbon group having 1 to 20 carbon atoms which may have an ether bond, an ester bond, and / or an amide bond.)

[0021] [ka] (In the general formula (3), R5 and R6 each independently represent "-H" or "-CH3", X5 and X6 each independently represent "-O-" or "-NH-", and Y5 and Y6 each independently represent a linear or branched hydrocarbon group having 1 to 20 carbon atoms which may have an ether bond, an ester bond, and / or an amide bond.)

[0022] The method for obtaining the structure represented by the general formula (1) is not particularly limited and can be appropriately selected depending on the purpose. The structure may be appropriately synthesized, or a commercially available product having the structure may be used. The commercially available product having the structure represented by the general formula (1) is not particularly limited and can be appropriately selected depending on the purpose. For example, trans-2,3-dibromo-2-butene-1,4-diol (manufactured by Tokyo Chemical Industry Co., Ltd.) can be mentioned.

[0023] The method for obtaining the structure represented by the general formula (2) is not particularly limited and can be appropriately selected depending on the purpose. The structure may be appropriately synthesized or a commercially available product having the structure may be used. The commercially available product having the structure represented by the general formula (2) is not particularly limited and can be appropriately selected depending on the purpose. For example, 2,2-bis(bromomethyl)-1,3-propanediol (manufactured by Tokyo Chemical Industry Co., Ltd.) can be mentioned.

[0024] The method for obtaining the structure represented by the general formula (3) is not particularly limited and can be appropriately selected depending on the purpose. The structure may be appropriately synthesized or a commercially available product having the structure may be used. As a method for synthesizing the structure represented by the general formula (3), for example, 2,2,3,3-tetrabromobutane-1,4-diol (TBBD) can be synthesized by adding Br2 to the triple bond of 2-butyne-1,4-diol.

[0025] The method for synthesizing the X-ray contrast compound is not particularly limited, but for example, the compound can be synthesized by the following method. [An example of a method for synthesizing an X-ray contrast compound] trans-2,3-dibromo-2-butene-1,4-diol, mono(2-acryloyloxyethyl) succinate, and a solution (e.g., water, ethyl acetate, or toluene) are heated under reflux overnight. At this time, if necessary, a catalyst (e.g., concentrated sulfuric acid or tosylic acid) and a condensing agent (e.g., N,N'-dicyclohexylcarbodiimide (DCC)) may be added. Also, if necessary, the synthesis may be performed under a protective gas atmosphere (e.g., nitrogen). The reaction product is then cooled to room temperature, extracted from the solution, washed at least once with water, dried over anhydrous Na2SO4, and the solvent is removed under vacuum.

[0026] The weight average molecular weight of the X-ray contrast compound is not particularly limited and can be appropriately selected depending on the purpose, but is preferably 100 or more and 5,000 or less, and more preferably 200 or more and 1,000 or less. When the weight-average molecular weight of the X-ray contrast compound is within the above numerical range, the X-ray contrast compound can be well mixed with other components described later when preparing the dental adhesive composition described later. Therefore, the dental adhesive composition described later can be easily prepared, and the operability during use of the dental adhesive composition can be improved, while ensuring appropriate adhesiveness, which is preferable.

[0027] (Dental adhesive composition) The dental adhesive composition of the present invention contains an X-ray contrast compound having a structural portion A which contains a halogen atom and is a non-cyclic structure, and a structural portion B which is derived from a (meth)acrylate, and may contain other components as necessary. The X-ray contrast compound is the same as that described in the above section (X-ray contrast compound), and therefore a duplicated description will be omitted.

[0028] The content of the X-ray contrast compound is not particularly limited and can be appropriately selected depending on the purpose, but is preferably from 0.5% by mass to 70% by mass, more preferably from 5% by mass to 60% by mass, and even more preferably from 15% by mass to 50% by mass, based on the total amount of the dental adhesive composition. It is preferable that the content of the X-ray contrast compound is 0.5% by mass or more based on the total amount of the dental adhesive composition, since this improves the X-ray contrast property of the cured product of the dental adhesive composition. When the content of the X-ray contrast compound is 70 mass% or less based on the total amount of the dental adhesive composition, the content of the other components described below can be sufficiently ensured, and various performance properties as a dental adhesive composition can be improved, which is preferable.

[0029] <Other ingredients> The other components are not particularly limited and can be appropriately selected depending on the purpose as long as the effects of the present invention are not impaired. Examples of the other components include a (meth)acrylate having an acid group, a (meth)acrylate not having an acid group, a polymerization initiator, a polymerization inhibitor, a filler, and a solvent.

[0030] <<(Meth)acrylates with acid groups>> Examples of the acid group in the (meth)acrylate having an acid group include a phosphoric acid group, a pyrophosphoric acid group, a thiophosphoric acid group, a sulfonic acid group, a phosphonic acid group, and a carboxylic acid group. Among these, from the viewpoints of the solubility of the smear layer on the tooth surface of the dental adhesive composition, the demineralization of tooth tissue, and in particular, the adhesiveness to enamel, (meth)acrylates having a phosphoric acid group, a thiophosphoric acid group, or a carboxylic acid group are preferred. The (meth)acrylate having an acid group may have a plurality of acid groups.

[0031] -(Meth)acrylate with phosphoric acid group- The (meth)acrylate having a phosphate group is not particularly limited and can be appropriately selected depending on the purpose. Examples thereof include 2-(meth)acryloyloxyethyl dihydrogen phosphate, bis[2-(meth)acryloyloxyethyl]hydrogen phosphate, 2-(meth)acryloyloxyethyl phenyl hydrogen phosphate, 6-(meth)acryloyloxyhexyl dihydrogen phosphate, 6-(meth)acryloyloxyhexyl phenyl hydrogen phosphate, 10-(meth)acryloyloxydecyl dihydrogen phosphate (MDP), 1,3-di(meth)acryloylpropane-2-dihydrogen phosphate, 1,3-di(meth)acryloylpropane-2-phenyl hydrogen phosphate, and bis[5-{2-(meth)acryloyloxyethoxycarbonyl}heptyl]hydrogen phosphate. These may be used alone or in combination of two or more.

[0032] --(Meth)acrylate with pyrophosphate group-- The (meth)acrylate having a pyrophosphate group is not particularly limited and can be appropriately selected depending on the purpose. Examples thereof include bis[2-(meth)acryloyloxyethyl] pyrophosphate, bis[4-(meth)acryloyloxybutyl] pyrophosphate, bis[6-(meth)acryloyloxyhexyl] pyrophosphate, bis[8-(meth)acryloyloxyoctyl] pyrophosphate, and bis[10-(meth)acryloyloxydecyl] pyrophosphate. These may be used alone or in combination of two or more.

[0033] -(Meth)acrylate with thiophosphate group- The (meth)acrylate having a thiophosphate group is not particularly limited and can be appropriately selected depending on the purpose. For example, 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 (MDTP), 11-( Examples of the acryloyloxy undecyl dihydrogen thiophosphate include 12-(meth)acryloyloxy dodecyl dihydrogen thiophosphate, 13-(meth)acryloyloxy tridecyl dihydrogen thiophosphate, 14-(meth)acryloyloxy tetradecyl dihydrogen thiophosphate, 15-(meth)acryloyloxy pentadecyl dihydrogen thiophosphate, 16-(meth)acryloyloxy hexadecyl dihydrogen thiophosphate, 17-(meth)acryloyloxy heptadecyl dihydrogen thiophosphate, 18-(meth)acryloyloxy octadecyl dihydrogen thiophosphate, 19-(meth)acryloyloxy nonadecyl dihydrogen thiophosphate, and 20-(meth)acryloyloxy icosyl dihydrogen thiophosphate. These may be used alone or in combination of two or more.

[0034] --(Meth)acrylate with Carboxylic Acid Group-- The (meth)acrylate having a carboxylic acid group is not particularly limited and can be appropriately selected depending on the purpose. Examples thereof include 2-methacryloyloxyethyl succinic acid, 4-(meth)acryloyloxyethyl trimellitic acid, 4-(meth)acryloyloxyethyl trimellitic acid anhydride, 4-(meth)acryloyloxydecyl trimellitic acid, 4-(meth)acryloyloxydecyl trimellitic acid anhydride, 11-(meth)acryloyloxy-1,1-undecanedicarboxylic acid, 1,4-di(meth)acryloyloxypyromellitic acid, 2-(meth)acryloyloxyethyl maleic acid, 2-(meth)acryloyloxyethyl phthalic acid, and 2-(meth)acryloyloxyethyl hexahydrophthalic acid. These may be used alone or in combination of two or more.

[0035] --(Meth)acrylate having sulfonic acid group-- The (meth)acrylate having a sulfonic acid group is not particularly limited and can be appropriately selected depending on the purpose. Examples thereof include 2-(meth)acrylamide-2-methylpropanesulfonic acid, styrenesulfonic acid, and 2-sulfoethyl (meth)acrylate. These may be used alone or in combination of two or more.

[0036] --(Meth)acrylate having a phosphonic acid group-- The (meth)acrylate having a phosphonic acid group is not particularly limited and can be appropriately selected depending on the purpose. Examples thereof include 2-(meth)acryloyloxyethyl phenyl phosphonate, 5-(meth)acryloyloxypentyl-3-phosphonopropionate, 6-(meth)acryloyloxyhexyl-3-phosphonopropionate, 10-(meth)acryloyloxydecyl-3-phosphonopropionate, 6-(meth)acryloyloxyhexyl-3-phosphonoacetate, and 10-(meth)acryloyloxydecyl-3-phosphonoacetate. These may be used alone or in combination of two or more.

[0037] These (meth)acrylates having an acid group may be used alone or in combination of two or more.

[0038] Among these, 10-(meth)acryloyloxydecyl dihydrogen phosphate (MDP), 10-(meth)acryloyloxydecyl dihydrogen thiophosphate (MDTP), and 4-(meth)acryloyloxyethyl trimellitic anhydride (4-META) are preferred in terms of improving the adhesive properties of the cured dental adhesive composition.

[0039] The content of the (meth)acrylate having an acid group is not particularly limited and can be appropriately selected depending on the purpose, but is preferably from 0.1% by mass to 40% by mass, more preferably from 1% by mass to 25% by mass, and even more preferably from 5% by mass to 25% by mass, relative to the total amount of the dental adhesive composition. If the content of the (meth)acrylate having an acid group is 0.1 mass % or more based on the total amount of the dental adhesive composition, the demineralizing power of the dental adhesive composition on tooth structure is further improved, which is preferable. It is preferable that the content of the (meth)acrylate having an acid group is 40 mass % or less based on the total amount of the dental adhesive composition, since the hardening property of the dental adhesive composition is improved.

[0040] <<(Meth)acrylates without acid groups>> The (meth)acrylate having no acid group is not particularly limited and can be appropriately selected depending on the purpose. For example, methyl (meth)acrylate, ethyl (meth)acrylate, isopropyl (meth)acrylate, n-butyl (meth)acrylate, isobutyl (meth)acrylate, hydroxypropyl (meth)acrylate, tetrahydrofurfuryl (meth)acrylate, glycidyl (meth)acrylate, 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, 3-hydroxypropyl (meth)acrylate, 4-hydroxypropyl (meth)acrylate, 5-hydroxypropyl (meth)acrylate, 6-hydroxypropyl (meth)acrylate, 7-hydroxypropyl (meth)acrylate, 8-hydroxypropyl (meth)acrylate, 9-hydroxypropyl (meth)acrylate, 10-hydroxypropyl (meth)acrylate, 11-hydroxypropyl (meth)acrylate, 12-hydroxypropyl (meth)acrylate, 13-hydroxypropyl (meth)acrylate, 14-hydroxypropyl (meth)acrylate, 15-hydroxypropyl (meth)acrylate, 16-hydroxypropyl (meth)acrylate, 17-hydroxypropyl (meth)acrylate, 18-hydroxypropyl (meth)acrylate, 19-hydroxypropyl (meth)acrylate, 20-hydroxypropyl (meth)acrylate, 21-hydroxypropyl (meth)acrylate, 22-hydroxypropyl (meth)acrylate, 23-hydroxypropyl (meth)acrylate, 24-hydroxypropyl (meth)acrylate, 25-hydroxypropyl (meth)acrylate, 26-hydroxypropyl (meth)acrylate, 27-hydroxypropyl (meth)acrylate, 28-hydroxypropyl (meth)acrylate, 29-hydroxypropyl (meth)acrylate, 30-hydroxypropyl (meth)acrylate, 31-hydroxypropyl (meth)acrylate, 32-hydroxypropyl (meth)acrylate, 33-hydroxypropyl (meth)acrylate, 34-hydroxypropyl (meth)acrylate, 35-hydroxypropyl (meth)acrylate, 36-hydroxypropyl (meth)acrylate, 37-hydroxypropyl (meth)acrylate, 38-hydroxypropyl (meth)acrylate, 39-hydroxypropyl (meth p)acrylate, 2-methoxyethyl (meth)acrylate, 2-ethoxyethyl (meth)acrylate, 2-methylhexyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, benzyl (meth)acrylate, 2-hydroxy-1,3-di(meth)acryloyloxypropane, ethylene glycol di(meth)acrylate, diethylene glycol di(meth)acrylate, triethylene glycol di(meth)acrylate, butylene glycol di(meth)acrylate, neopentyl glycol di(meth)acrylate, 1,3-butanediol di(meth)acrylate, 1,4-butanediol di(meth)acrylate, 1,6-hexanediol di(meth)acrylate, trimethylolpropane tri(meth)acrylate, trimethylolethane tri(meth)acrylate, pentaerythritol tri(meth)acrylate, trimethylolmethane tri(meth)acrylate, pentaerythritol tetra(meth)acrylate, polybutylene glycol di(meth)acrylate, bisphenol A diglycidyl (meth)acrylate, di-2-(meth)a Examples of the acryloyloxyethyl-2,2,4-trimethylhexamethylene dicarbamate include 1,3,5-tris[1,3-bis{(meth)acryloyloxy}-2-propoxycarbonylaminohexane]-1,3,5-(1H,3H,5H)triazine-2,4,6-trione, 2,2-bis[4-(3-(meth)acryloyloxy-2-hydroxypropyl)phenyl]propane, and N,N'-(2,2,4-trimethylhexamethylene)bis[2-(aminocarboxy)propane-1,3-diol]tetramethacrylate. These (meth)acrylates having no acid group may be used alone or in combination of two or more kinds.

[0041] Among these, 2-hydroxy-1,3-di(meth)acryloyloxypropane (GDMA) and triethylene glycol di(meth)acrylate (TEGDMA) are preferred in terms of improving the mechanical strength of the cured dental adhesive composition and improving adhesion to ceramics and teeth.

[0042] The content of the (meth)acrylate not having an acid group is not particularly limited and can be appropriately selected depending on the purpose, but is preferably from 3% by mass to 50% by mass, more preferably from 5% by mass to 40% by mass, and even more preferably from 10% by mass to 30% by mass, based on the total amount of the dental adhesive composition. It is preferable that the content of the (meth)acrylate having no acid group is 3 mass % or more based on the total amount of the dental adhesive composition, since this can improve the operability of the dental adhesive composition. When the content of the (meth)acrylate having no acid group is 50 mass % or less based on the total amount of the dental adhesive composition, the mechanical strength of the cured product obtained by curing the dental adhesive composition can be improved, which is preferable.

[0043] <<Polymerization initiator>> The polymerization initiator is not particularly limited and may be appropriately selected depending on the purpose, and examples thereof include chemical polymerization initiators, photopolymerization initiators, etc. Among these, photopolymerization initiators are preferred since the dental adhesive composition is often cured by irradiation with visible light or the like.

[0044] Examples of the chemical polymerization initiator include thiourea derivatives, vanadium compounds, tertiary amines, and organic peroxides.

[0045] -Thiourea derivatives- The thiourea derivative functions as a reducing agent among chemical polymerization initiators. The thiourea derivative is not particularly limited and can be appropriately selected depending on the purpose. Examples of the thiourea derivative include ethylenethiourea, N-methylthiourea, N-ethylthiourea, N-propylthiourea, N-butylthiourea, N-laurylthiourea, N-phenylthiourea, N-cyclohexylthiourea, N,N-dimethylthiourea, N,N-diethylthiourea, N,N-dipropylthiourea, N,N-dibutylthiourea, N,N-dilaurylthiourea, N,N-diphenylthiourea, N,N-dicyclohexylthiourea, trimethylthiourea, tetramethylthiourea, N-acetylthiourea, N-benzoylthiourea, 1-allyl-3-(2-hydroxyethyl)-2-thiourea, 1-(2-tetrahydrofurfuryl)-2-thiourea, N-tert-butyl-N'-isopropylthiourea, and 2-pyridylthiourea. Among these, N-benzoylthiourea is preferred from the viewpoint of improving the curability of the dental adhesive composition. These thiourea derivatives may be used alone or in combination of two or more.

[0046] The content of the thiourea derivative is not particularly limited and can be appropriately selected depending on the purpose, but is preferably from 0.1% by mass to 5% by mass, more preferably from 0.1% by mass to 3% by mass, and even more preferably from 0.1% by mass to 1% by mass, based on the total amount of the dental adhesive composition. When the content of the thiourea derivative is 0.1% by mass or more based on the total amount of the dental adhesive composition, the hardening property of the dental adhesive composition is improved, which is preferable. If the content of the thiourea derivative is 5% by mass or less based on the total amount of the dental adhesive composition, the solubility of the thiourea derivative in the X-ray contrast compound is improved, which is preferable.

[0047] --Vanadium compounds-- The vanadium compound functions as a reducing agent among chemical polymerization initiators. The vanadium compound is not particularly limited and can be appropriately selected depending on the purpose. Examples thereof include oxovanadium oxalate, vanadyl acetylacetonate, vanadium acetylacetonate, vanadyl stearate, vanadium naphthenate, and vanadium benzoylacetonate. Among these, vanadyl acetylacetonate is preferred from the viewpoint of the curability of the dental adhesive composition. These vanadium compounds may be used alone or in combination of two or more.

[0048] The content of the vanadium compound is not particularly limited and can be appropriately selected depending on the purpose, but is preferably from 0.001% by mass to 5% by mass, more preferably from 0.0015% by mass to 1% by mass, and even more preferably from 0.002% by mass to 0.1% by mass, relative to the total amount of the dental adhesive composition. When the content of the vanadium compound is 0.001% by mass or more based on the total amount of the dental adhesive composition, the hardening property of the dental adhesive composition is improved, which is preferable. If the content of the vanadium compound is 5 mass % or less based on the total amount of the dental adhesive composition, the storage stability of the dental adhesive composition is improved, which is preferable.

[0049] -Tertiary amine- The tertiary amine functions as a reducing agent among chemical polymerization initiators, and can also function as a photopolymerization accelerator. The tertiary amine is not particularly limited and can be appropriately selected depending on the purpose. Examples of the tertiary amine include tertiary aliphatic amines and tertiary aromatic amines.

[0050] Examples of the tertiary aliphatic amine include N,N-dimethylaminoethyl methacrylate and triethanolamine.

[0051] Examples of the tertiary aromatic amine include alkyl p-dialkylaminobenzoates, 7-dimethylamino-4-methylcoumarin, N,N-dimethylaniline, N,N-dibenzylaniline, N,N-dimethyl-p-toluidine, N,N-diethyl-p-toluidine, N,N-bis(2-hydroxyethyl)-p-toluidine, N,N,2,4,6-pentamethylaniline, N,N,2,4-tetramethylaniline, and N,N-diethyl-2,4,6-trimethylaniline.

[0052] Among these, tertiary aromatic amines are preferred, and alkyl p-dialkylaminobenzoates are more preferred.

[0053] Examples of the alkyl p-dialkylaminobenzoate include methyl p-dimethylaminobenzoate, ethyl p-dimethylaminobenzoate, propyl p-dimethylaminobenzoate, amyl p-dimethylaminobenzoate, isoamyl p-dimethylaminobenzoate, ethyl p-diethylaminobenzoate, and propyl p-diethylaminobenzoate.

[0054] These tertiary amines may be used alone or in combination of two or more kinds.

[0055] -Organic peroxide- Among the chemical polymerization initiators, the organic peroxide functions as an oxidizing agent. Examples of the organic peroxide include benzoyl peroxide, cumene hydroperoxide, t-butyl hydroperoxide, t-amyl hydroperoxide, 1,1,3,3-tetramethylbutyl hydroperoxide, 2,5-dimethyl-2,5-di(hydroperoxy)hexane, p-diisopropylbenzene monohydroperoxide, p-methane hydroperoxide, and pinane hydroperoxide. Among these, cumene hydroperoxide is preferred from the viewpoint of the curing property of the dental adhesive composition. These organic peroxides may be used alone or in combination of two or more kinds.

[0056] The content of the organic peroxide is not particularly limited and can be appropriately selected depending on the purpose, but is preferably from 0.01% by mass to 10% by mass, more preferably from 0.05% by mass to 5% by mass, and even more preferably from 0.1% by mass to 3% by mass, based on the total amount of the dental adhesive composition. When the content of the organic peroxide is 0.01% by mass or more based on the total amount of the dental adhesive composition, the hardening property of the dental adhesive composition is improved, which is preferable. If the content of the organic peroxide is 10% by mass or less based on the total amount of the dental adhesive composition, the pot life of the dental adhesive composition is improved, which is preferable.

[0057] The photopolymerization initiator is not particularly limited and can be appropriately selected depending on the purpose. Examples of the photopolymerization initiator include camphorquinone (CQ), ethyl 4-dimethylaminobenzoate (EPA), 2,4,6-trimethylbenzoyldiphenylphosphine oxide (TPO), phenylbis(2,4,6-trimethylbenzoyl)phosphine oxide, benzyl ketal, diacetyl ketal, benzyl dimethyl ketal, benzyl diethyl ketal, benzyl bis(2-methoxyethyl)ketal, 4,4'-dimethyl(benzyl dimethyl ketal), anthraquinone, 1-chloroanthraquinone, 2-chloroanthraquinone, 1,2-benzanthraquinone, 1-hydroxyanthraquinone, 1-methylanthraquinone, and the like. Examples of thioxanthone include laquinone, 2-ethyl anthraquinone, 1-bromo anthraquinone, thioxanthone, 2-isopropyl thioxanthone, 2-nitro thioxanthone, 2-methyl thioxanthone, 2,4-dimethyl thioxanthone, 2,4-diethyl thioxanthone, 2,4-diisopropyl thioxanthone, 2-chloro-7-trifluoromethyl thioxanthone, thioxanthone-10,10-dioxide, thioxanthone-10-oxide, benzoin methyl ether, benzoin ethyl ether, benzoin isopropyl ether, benzoin isobutyl ether, benzophenone, bis(4-dimethylaminophenyl)ketone, and 4,4'-bis(diethylamino)benzophenone. Among these, camphorquinone (CQ), ethyl 4-dimethylaminobenzoate (EPA), and 2,4,6-trimethylbenzoyldiphenylphosphine oxide (TPO) are preferred from the viewpoint of improving the curing property of the dental adhesive composition. These photopolymerization initiators may be used alone or in combination of two or more.

[0058] The content of the photopolymerization initiator is not particularly limited and can be appropriately selected depending on the purpose, but is preferably from 0.01% by mass to 10% by mass, more preferably from 0.05% by mass to 8% by mass, and even more preferably from 1% by mass to 5% by mass, relative to the total amount of the dental adhesive composition. When the content of the photopolymerization initiator is 0.01% by mass or more based on the total amount of the dental adhesive composition, the hardening property of the dental adhesive composition is improved, which is preferable. If the content of the photopolymerization initiator is 10% by mass or less based on the total amount of the dental adhesive composition, the pot life of the dental adhesive composition is improved, which is preferable.

[0059] <<Polymerization inhibitor>> The polymerization inhibitor is not particularly limited and can be appropriately selected depending on the purpose. Examples of the polymerization inhibitor include dibutylhydroxytoluene (2,6-di-tert-butyl-p-cresol) (BHT), 6-tert-butyl-2,4-xylenol, 1,4-dihydroxybenzene (HQ), and 4-methoxyphenol (MEHQ). Among these, dibutylhydroxytoluene (BHT) is preferred from the viewpoint of improving the curing property of the dental adhesive composition. These polymerization inhibitors may be used alone or in combination of two or more kinds.

[0060] The content of the polymerization inhibitor is not particularly limited and can be appropriately selected depending on the purpose, but is preferably from 0.01% by mass to 5% by mass, more preferably from 0.05% by mass to 3% by mass, and even more preferably from 0.1% by mass to 1% by mass, relative to the total amount of the dental adhesive composition. It is preferable that the content of the polymerization inhibitor is 0.01% by mass or more and 5% by mass or less based on the total amount of the dental adhesive composition, since this improves the storage stability of the dental adhesive composition.

[0061] <<Filler>> The filler is not particularly limited and can be appropriately selected depending on the purpose. Examples of the filler include colloidal silica, fine particle silica whose surface has been treated to make it hydrophobic (hydrophobic fumed silica), aluminum oxide, fluoroaluminosilicate glass, barium glass, and strontium glass. Among these, hydrophobic fumed silica (eg, Aerosil (registered trademark)) is preferred. These fillers may be used alone or in combination of two or more.

[0062] The content of the filler is not particularly limited and can be appropriately selected depending on the purpose, but is preferably from 0.1% by mass to 30% by mass, more preferably from 0.5% by mass to 20% by mass, and even more preferably from 1% by mass to 10% by mass, relative to the total amount of the dental adhesive composition. When the content of the filler is 0.1 mass % or more relative to the total amount of the dental adhesive composition, the viscosity of the dental adhesive composition becomes high, and the handleability of the dental adhesive composition can be improved, which is preferable. When the content of the filler is 30 mass % or less based on the total amount of the dental adhesive composition, the viscosity of the dental adhesive composition does not become too high, and the handleability of the dental adhesive composition can be stabilized.

[0063] <<Solvent>> The solvent is not particularly limited and can be appropriately selected depending on the purpose. Examples of the solvent include water and organic solvents. The organic solvent is not particularly limited and can be appropriately selected depending on the purpose. Examples of the organic solvent include ethanol, acetone, and propanol. These solvents may be used alone or in combination of two or more.

[0064] The X-ray contrast property of the cured product of the X-ray contrast compound is not particularly limited and may be appropriately selected depending on the purpose, but it is preferably 100% or more in terms of the ratio to aluminum. The method for evaluating the X-ray contrast property of the cured product of the dental adhesive composition is not particularly limited and can be appropriately selected depending on the purpose. For example, it can be measured by the X-ray contrast property test method for dental materials in accordance with ISO 13116 and JIS T 6006.

[0065] [Physical properties of dental adhesive composition] The physical properties of the dental adhesive composition are not particularly limited, but the pH and viscosity are preferably as follows.

[0066] The pH of the dental adhesive composition is preferably from 1 to 10, and more preferably from 1.5 to 8. A dental adhesive composition having a pH in the above range has little acidic or basic irritation, is excellent in feel when used, and can stably maintain its characteristics against environmental changes even when stored for a long period of time. The method for measuring the pH is not particularly limited, but an example thereof includes a method in which 1 g of the dental adhesive composition is dissolved in 1 mL of an aqueous solvent, and the resulting solution is measured using a pH meter (e.g., HORIBA pH / ION METER F-72).

[0067] The viscosity of the dental adhesive composition is preferably from 10 mPa·s to 1000 mPa·s, more preferably from 50 mPa·s to 500 mPa·s. A dental adhesive composition having a viscosity within the above range has excellent operability and exhibits high compatibility with an adherend. The method for measuring the viscosity is not particularly limited, but the viscosity can be measured, for example, by the following method. [An example of a viscosity measurement method] After a B-type viscometer (Toki Sangyo Co., Ltd.) is kept at a constant temperature of 23° C., 0.6 mL of the dental adhesive composition is measured out and left to stand for 5 minutes to keep the temperature constant. Measurement is performed for 5 minutes at 10 rpm, and the average value after 2 minutes and 5 minutes is taken as the viscosity.

[0068] The method for producing the dental adhesive composition is not particularly limited, and it can be produced, for example, by mixing and stirring the above-mentioned components.

[0069] The application of the dental adhesive composition is not particularly limited, but it can be used, for example, for various dental materials. Examples of the dental materials include dental cements, dental adhesives, dental temporary sealing materials, dental primers, dental coating materials, dental filling composite resins, dental hard resins, dental cutting resin materials, dental temporary restorative materials, dental filling materials, and dentifrices. Among these, it is preferably used in dental adhesives, dental filling composite resins, and dental cements. EXAMPLES

[0070] The present invention will be further described below with reference to examples. In the following, numerical values ​​without units, "parts" or "%" are based on mass unless otherwise specified.

[0071] <Synthesis of Compounds 1 to 5> <<Synthesis of Compound 1>> trans-2,3-dibromo-2-butene-1,4-diol (Tokyo Chemical Industry Co., Ltd.), mono(2-acryloyloxyethyl) succinate (Tokyo Chemical Industry Co., Ltd.), and the solution were heated under reflux overnight. At this time, a catalyst and a condensing agent were added together, and the synthesis was carried out under a protective gas atmosphere. Then, the reaction product was cooled to room temperature, and the reaction product was extracted with the solution, washed with water at least once, dried over anhydrous Na2SO4, and the solvent was removed under vacuum to obtain compound 1. Here, the structure of trans-2,3-dibromo-2-butene-1,4-diol is as follows:

[0072] [ka]

[0073] Here, the structure of mono(2-acryloyloxyethyl) succinate is as follows:

[0074] [ka]

[0075] <<Synthesis of compound 2>> Compound 2 was obtained in the same manner as Compound 1, except that 2-carboxyethyl acrylate (manufactured by Tokyo Chemical Industry Co., Ltd.) was used instead of mono(2-acryloyloxyethyl) succinate. The structure of 2-carboxyethyl acrylate is as follows.

[0076] [ka]

[0077] <<Synthesis of compound 3>> Compound 3 was obtained in the same manner as Compound 1, except that 2,2-bis(bromomethyl)-1,3-propanediol (manufactured by Tokyo Chemical Industry Co., Ltd.) was used instead of trans-2,3-dibromo-2-butene-1,4-diol. The structure of 2,2-bis(bromomethyl)-1,3-propanediol is as follows.

[0078] [ka]

[0079] <<Synthesis of compound 4>> Compound 4 was obtained in the same manner as Compound 1, except that trans-2-butene-1,4-diol (manufactured by Tokyo Chemical Industry Co., Ltd.) was used instead of trans-2,3-dibromo-2-butene-1,4-diol. The structure of trans-2-butene-1,4-diol is as follows.

[0080] [ka]

[0081] <<Synthesis of compound 5>> Compound 5 was obtained in the same manner as Compound 1, except that 2,5-dibromo-1,4-benzenediol (manufactured by Tokyo Chemical Industry Co., Ltd.) was used instead of trans-2,3-dibromo-2-butene-1,4-diol. The structure of 2,5-dibromo-1,4-benzenediol is as follows.

[0082] [ka]

[0083] (Examples 1 to 9, Comparative Examples 1 to 3) <Preparation of Dental Adhesive Composition> Dental adhesive compositions (Examples 1 to 9, Comparative Examples 1 to 3) having the compositions shown in Tables 1 to 2 were prepared. For each dental adhesive composition, radiopacity, halogen release degree, adhesion strength to ceramics, and adhesion strength to dentin were evaluated by the following methods. The results are shown in Tables 1 to 2.

[0084] <Evaluation of Radiopacity> When actually using the dental adhesive composition, after applying the dental adhesive composition to the adherend, it is dried with air to remove the solvent and then photocured. Based on this, for the evaluation of radiopacity, those obtained by removing the solvent component from the compositions of the dental adhesive compositions of Examples 1 to 9 and Comparative Examples 1 to 3 were used. An OHP sheet was laid on a slide glass, and a ring with a diameter of Φ1.5 cm and a thickness of 1.0 mm was placed thereon. After filling each dental adhesive composition from which the solvent had been removed into the ring, an OHP sheet and a slide glass were placed thereon in order to prepare an evaluation sample. Using a light irradiator (G-Light Prima II Plus, manufactured by GC Corporation), each of the front and back sides of the evaluation sample was irradiated 9 times in a 10-second mode. The obtained cured product was subjected to cephalometric radiography using an X-ray imaging device (Aadva GX-100 2D, manufactured by GC Corporation) together with an aluminum step. The obtained image was analyzed with image J to calculate the radiopacity (%) against aluminum. The evaluation criteria for radiopacity are as follows. -Evaluation Criteria- A: The radiopacity against aluminum is 100% or more. B: The radiopacity against aluminum is 50% or more and less than 100%. C: The radiopacity against aluminum is less than 50%.

[0085] <Evaluation of Halogen Release Degree> One drop of each dental adhesive composition was dropped onto a dish and then allowed to stand in natural light for 10 minutes. Thereafter, the color change of the dental adhesive composition was visually observed. No visible change in color of the dental adhesive compositions of Examples 1 to 9 and Comparative Examples 1 and 3 was observed, but discoloration was observed only in the dental adhesive composition of Comparative Example 2. It is presumed that the discoloration of the dental adhesive composition is caused by the halogen in the dental adhesive composition being liberated by natural light.

[0086] <Evaluation of adhesive strength to enamel and to dentin> The tooth structure was polished with #400 waterproof abrasive paper to expose the fresh surface. Each dental adhesive composition was applied and immediately dried by air blowing. A plastic mold with a Φ2.38mm hole was placed on the test surface, and light irradiation was performed for 10 seconds from above the mold using a light irradiator (G-Light Prima II Plus, manufactured by GC Corporation). Next, composite resin was filled and light irradiation was performed for another 20 seconds. After immersion in water at 37°C for 24 hours, a shear test was performed on five test specimens using an autograph (EZ-S, SHIMADZU) at a crosshead speed of 1 mm / min to obtain the average value of the shear bond strength and evaluate the adhesiveness of each composite resin to the tooth structure. The evaluation criteria for adhesion (adhesive strength to enamel and adhesive strength to dentin) of the composite resin to tooth structures (enamel, dentin) when each dental adhesive composition was used were as follows. -Evaluation criteria- A: The average shear bond strength is 15 MPa or more. B: The average shear bond strength is less than 15 MPa.

[0087] [Table 1]

[0088] [Table 2]

[0089] For example, aspects of the present invention are as follows. <1> A structural portion A containing a halogen atom and having a non-cyclic structure; and a structural portion B derived from a (meth)acrylate. <2> The X-ray contrast compound includes at least one selected from the group consisting of a structure represented by the following general formula (1), a structure represented by the following general formula (2), and a structure represented by the following general formula (3): <1> The compound is an X-ray contrast compound according to the above. [ka] (In the general formula (1), R1 and R2 each independently represent "-H" or "-CH3", X1 and X2 each independently represent "-O-" or "-NH-", and Y1 and Y2 each independently represent a linear or branched hydrocarbon group having from 1 to 20 carbon atoms, which may have an ether bond, an ester bond, and / or an amide bond.) [ka] (In the general formula (2), R3 and R4 each independently represent "-H" or "-CH3", X3 and X4 each independently represent "-O-" or "-NH-", and Y3 and Y4 each independently represent a linear or branched hydrocarbon group having 1 to 20 carbon atoms which may have an ether bond, an ester bond, and / or an amide bond.) [ka] (In the general formula (3), R5 and R6 each independently represent "-H" or "-CH3", X5 and X6 each independently represent "-O-" or "-NH-", and Y5 and Y6 each independently represent a linear or branched hydrocarbon group having 1 to 20 carbon atoms which may have an ether bond, an ester bond, and / or an amide bond.) <3> A structural portion A containing a halogen atom and having a non-cyclic structure; The dental adhesive composition is characterized by comprising an X-ray contrast compound having a structural portion B derived from a (meth)acrylate. <4> The X-ray contrast compound includes at least one selected from the group consisting of a structure represented by the following general formula (1), a structure represented by the following general formula (2), and a structure represented by the following general formula (3): <3> 1. A dental adhesive composition according to claim 1. [ka] (In the general formula (1), R1 and R2 each independently represent "-H" or "-CH3", X1 and X2 each independently represent "-O-" or "-NH-", and Y1 and Y2 each independently represent a linear or branched hydrocarbon group having from 1 to 20 carbon atoms, which may have an ether bond, an ester bond, and / or an amide bond.) [ka] (In the general formula (2), R3 and R4 each independently represent "-H" or "-CH3", X3 and X4 each independently represent "-O-" or "-NH-", and Y3 and Y4 each independently represent a linear or branched hydrocarbon group having 1 to 20 carbon atoms which may have an ether bond, an ester bond, and / or an amide bond.) [ka] (In the general formula (3), R5 and R6 each independently represent "-H" or "-CH3", X5 and X6 each independently represent "-O-" or "-NH-", and Y5 and Y6 each independently represent a linear or branched hydrocarbon group having 1 to 20 carbon atoms which may have an ether bond, an ester bond, and / or an amide bond.) <5> The photopolymerization initiator is contained in the above. <3> or the above <4> 1. A dental adhesive composition according to claim 1. <6> The above, which contains water <3> From the above <5> 10. The dental adhesive composition according to claim 9, wherein the dental adhesive composition is a <7> The dental adhesive composition has an X-ray contrast property of 100% or more in a cured product relative to aluminum. <3> From the above <6> 10. The dental adhesive composition according to claim 9, wherein the dental adhesive composition is a <8> The content of the X-ray contrast compound is 0.5% by mass or more and 70% by mass or less based on the total amount of the dental adhesive composition. <3> From the above <7> 10. The dental adhesive composition according to claim 9, wherein the dental adhesive composition is a

[0090] The above <1> or <2> and <3> From the above <8> According to the dental adhesive composition described in any one of the above, the conventional problems can be solved and the object of the present invention can be achieved.

Claims

1. A structural portion A containing a halogen atom and having a non-cyclic structure; and a structural portion B derived from a (meth)acrylate.

2. The X-ray contrast compound according to claim 1, which comprises at least one selected from the group consisting of a structure represented by the following general formula (1), a structure represented by the following general formula (2), and a structure represented by the following general formula (3): 【Chemistry 1】 (In the general formula (1), R1 and R2 are each independently “—H” or “—CH ３ ", X1 and X2 each independently represent "-O-" or "-NH-", and Y1 and Y2 each independently represent a linear or branched hydrocarbon group having 1 to 20 carbon atoms which may have an ether bond, an ester bond, and / or an amide bond.) 【Chemistry 2】 (In the general formula (2), R3 and R4 are each independently “—H” or “—CH ３ ", X3 and X4 each independently represent "-O-" or "-NH-", and Y3 and Y4 each independently represent a linear or branched hydrocarbon group having 1 to 20 carbon atoms which may have an ether bond, an ester bond, and / or an amide bond.) 【Chemistry 3】 (In the general formula (3), R5 and R6 are each independently “—H” or “—CH ３ X5 and X6 each independently represent "-O-" or "-NH-", and Y5 and Y6 each independently represent a linear or branched hydrocarbon group having from 1 to 20 carbon atoms which may have an ether bond, an ester bond, and / or an amide bond.)

3. A structural portion A containing a halogen atom and having a non-cyclic structure; A dental adhesive composition comprising an X-ray contrast compound having a structural portion B derived from a (meth)acrylate.

4. The dental adhesive composition according to claim 3 , wherein the X-ray contrast compound comprises at least one selected from the group consisting of a structure represented by the following general formula (1), a structure represented by the following general formula (2), and a structure represented by the following general formula (3): 【Chemistry 4】 (In the general formula (1), R1 and R2 are each independently “—H” or “—CH ３ ", X1 and X2 each independently represent "-O-" or "-NH-", and Y1 and Y2 each independently represent a linear or branched hydrocarbon group having 1 to 20 carbon atoms which may have an ether bond, an ester bond, and / or an amide bond.) 【Chemistry 5】 (In the general formula (2), R3 and R4 are each independently “—H” or “—CH ３ ", X3 and X4 each independently represent "-O-" or "-NH-", and Y3 and Y4 each independently represent a linear or branched hydrocarbon group having 1 to 20 carbon atoms which may have an ether bond, an ester bond, and / or an amide bond.) 【Chemistry 6】 (In the general formula (3), R5 and R6 are each independently “—H” or “—CH ３ X5 and X6 each independently represent "-O-" or "-NH-", and Y5 and Y6 each independently represent a linear or branched hydrocarbon group having from 1 to 20 carbon atoms which may have an ether bond, an ester bond, and / or an amide bond.)

5. The dental adhesive composition according to claim 3 or 4, which contains a photopolymerization initiator.

6. The dental adhesive composition according to claim 3 or 4, which contains water.

7. 5. The dental adhesive composition according to claim 3, wherein the X-ray contrast property of the cured product of said dental adhesive composition is 100% or more relative to aluminum.

8. 5. The dental adhesive composition according to claim 3, wherein the content of the X-ray contrast compound is 0.5% by mass or more and 70% by mass or less based on the total amount of the dental adhesive composition.

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