Dental adhesive composition

Abstract

To provide a one-pack type dental adhesive composition which cures easily without requiring curing at a stage prior to filling of a filling material and is applicable to various filling materials.SOLUTION: There is provided a one-pack type dental adhesive composition for bonding a photocurable filling material to dentin, which comprises 100 pts.mass of (A) a polymerizable monomer containing 1 to 40 pts.mass of (a1) an acidic group-containing polymerizable monomer, 0.1 to 50 pts.mass of (B) a radical polymerizable group-containing liquid polymer, 0.1 to 10 pts.mass of (C) a photopolymerization initiator, 1 to 50 pts.mass of (D) water and 10 to 300 pts.mass of (E) an organic solvent.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] This invention relates to dental adhesive compositions. [Background technology]

[0002] To repair teeth damaged by caries or other causes, a hardening filling material called composite resin is used. Such filling materials have very little adhesion to the tooth structure. Therefore, the filling material is usually bonded to the tooth structure via an adhesive. Common adhesives need to be pre-cured to achieve high adhesive strength.

[0003] As an adhesive that can be used to bond filling materials, photocurable adhesives that can be cured by light irradiation are known (see, for example, Patent Document 1). Photocurable adhesives need to be cured by light irradiation in the oral cavity before filling with the filling material. For photocurable adhesives to cure, light irradiation for several seconds to tens of seconds is required.

[0004] Therefore, light-curing adhesives can be burdensome for patients due to prolonged treatment times and heat generated during light irradiation. Furthermore, because light-curing adhesives are exposed to the oral cavity during light irradiation, they can be contaminated by the patient's saliva and blood. For these reasons, there is a need for adhesives that do not require light irradiation before filling.

[0005] Patent Document 2 discloses an adhesive that does not require curing by light irradiation. This adhesive is a two-component type, meaning that chemical polymerization curing proceeds when the first and second components are mixed. However, with this adhesive, mixing the first and second components during treatment is time-consuming and requires effort.

[0006] Furthermore, Patent Document 3 discloses a one-component dental adhesive that does not require light irradiation. With this adhesive, after filling with the filling material, photopolymerization curing proceeds due to the light irradiated during the curing of the filling material, and chemical polymerization curing proceeds due to the supply of aromatic amines from the filling material, thus eliminating the need for separate time and effort to cure the adhesive. However, this adhesive cannot be applied to filling materials other than those containing aromatic amines. [Prior art documents] [Patent Documents]

[0007] [Patent Document 1] Japanese Patent Publication No. 2009-137960 [Patent Document 2] Japanese Patent Publication No. 2018-027913 [Patent Document 3] Japanese Patent Publication No. 2020-138911 [Overview of the project] [Problems that the invention aims to solve]

[0008] Therefore, in order to achieve rapid and minimally invasive tooth treatment, there is a need for a one-component adhesive that does not require light irradiation before filling, hardens easily, and can be used universally. However, currently, adhesives with such a configuration are only known that are not compatible with general-purpose filling materials.

[0009] In view of the above circumstances, the object of the present invention is to provide a one-component dental adhesive composition that does not require curing before filling the filling material, cures easily, and is applicable to various filling materials. [Means for solving the problem]

[0010] To achieve the above objective, a dental adhesive composition according to one embodiment of the present invention is a one-component type for bonding a light-curing filling material to tooth structure. The above dental adhesive composition contains 100 parts by mass of (A) polymerizable monomer including 1 to 40 parts by mass of (a1) acidic group-containing polymerizable monomer, 0.1 to 50 parts by mass of (B) radical polymerizable group-containing liquid polymer, 0.1 to 10 parts by mass of (C) photopolymerization initiator, 1 to 50 parts by mass of (D) water, and 10 to 300 parts by mass of (E) organic solvent.

[0011] A dental adhesive composition according to one embodiment of the present invention is used in a one-component, light-curing adhesive that hardens upon light irradiation. In the dental adhesive composition according to one embodiment of the present invention, the inclusion of (a1) an acidic group-containing polymerizable monomer in (A) the polymerizable monomer improves adhesion to tooth structure. Furthermore, the inclusion of a radical polymerizable group in (B) a radical polymerizable group-containing liquid polymer (hereinafter also simply referred to as "(B) polymer") improves the curability of the dental adhesive composition and its adhesion to the filling material. In addition, the liquid nature of (B) polymer improves its compatibility with tooth structure and filling material, improving its penetration into the tooth surface and its compatibility with the filling material. As a result, the dental adhesive composition according to one embodiment of the present invention exhibits high adhesion to the tooth surface and filling material.

[0012] When curing a dental adhesive composition according to one embodiment of the present invention, polymerization proceeds on polymer (B), which originally has a certain degree of polymerization. As a result, compared to a dental adhesive composition composed of monomer components, there are fewer unbonded sites, and it can be easily cured with fewer radicals. This makes it possible to obtain a dental adhesive composition that can be cured using a small amount of light transmitted through the filling material. Therefore, it is possible to realize an adhesive that does not require curing before filling the filling material, cures easily, and is applicable to various filling materials regardless of the composition of the filling material. Furthermore, during curing, (a1) the acidic group-containing polymerizable monomer undergoes radical polymerization through the action of (C) the photopolymerization initiator, and (B) copolymerizes with the radical polymerizable group-containing liquid polymer, thereby curing together an adhesive component that adheres to the tooth surface and the filling material, resulting in an adhesive layer with higher adhesive strength.

[0013] The above liquid polymer containing a radical-polymerizable group may have 5 to 80 mol% of a structural unit (X) represented by the following general formula (1), 15 to 90 mol% of a structural unit (Y) represented by the following general formula (2), and 0 to 50 mol% of a structural unit (Z) represented by the following general formula (3).

Chemical formula

Chemical formula

Chemical formula

Chemical formula

[0014] The curability of the dental adhesive composition and the adhesiveness to the filling material are further improved by the radically polymerizable group contained in the structural unit (X). Further, the adhesiveness to dentin is further improved by the structural unit (Z) containing an acidic group. And the structural unit (Y) has a specific alkyl group which may contain an ethylene glycol chain, so that the compatibility with dentin and the filling material becomes better, and the permeability to the tooth surface and the compatibility with the filling material are easily improved. Thereby, the dental adhesive composition containing the polymer according to one embodiment of the present invention exhibits higher adhesiveness to the tooth surface and the filling material.

[0015] In the above general formula (2), when R 3 is a hydrogen atom, R 4 is a group having 1 to 15 carbon atoms in total, and when R 3 is a methyl group, R 4 may represent a group having 4 to 15 carbon atoms in total. Thereby, (B) becomes a liquid state having appropriate fluidity, and when the dental adhesive composition according to one embodiment of the present invention is applied to the tooth surface as a dental adhesive, it easily adheres to the tooth surface, and is also easily compatible with the filling material, so that an adhesive layer having higher adhesive strength can be formed.

[0016] The above (C) photoinitiator may contain (c1) bisacylphosphine oxide. Due to the action of (c1) bisacylphosphine oxide which is a highly active photoinitiator of the unimolecular cleavage type, curing proceeds more sufficiently even with a small amount of light, and the degree of polymerization becomes higher, so that an adhesive layer having higher adhesive strength can be obtained.

[0017] The above (B) radically polymerizable group-containing liquid polymer may contain 20 to 80 mol% of the structural unit (X) represented by the above general formula (1). Thereby, the curability of the dental adhesive composition and the adhesiveness to the filling material can be made better.

[0018] The above (B) radical polymerizable group-containing liquid polymer may contain 5 to 50 mol% of the structural unit (Z) represented by the above general formula (3). This can improve adhesion to tooth structure.

[0019] The weight-average molecular weight of the above polymer, as measured by gel permeation chromatography (GPC) using styrene as a standard, may be between 1,000 and 50,000. This results in an appropriate viscosity, which improves adhesion to the tooth surface and filling material, leading to higher adhesive strength.

[0020] The above dental adhesive composition may contain 10 to 30 parts by mass of fumed silica having an average primary particle diameter of 1 nm to 20 nm. By including the above-mentioned fumed silica as a filler, an adhesive layer with higher bonding strength can be obtained. Furthermore, by using fumed silica with a small average primary particle size, the fumed silica is less likely to settle even when the amount added is increased. Therefore, by increasing the amount of fumed silica added, an adhesive layer with even higher bonding strength can be formed. [Effects of the Invention]

[0021] According to the present invention, it is possible to provide a polymer that hardens easily without the need for light irradiation in the stage before filling the filling material, and that is applicable to various filling materials, as well as a dental adhesive composition containing the same. [Brief explanation of the drawing]

[0022] [Figure 1] This is a schematic partial cross-sectional view illustrating the process of bonding a filling material to a tooth using an adhesive composition according to one embodiment of the present invention. [Modes for carrying out the invention]

[0023] The embodiments for carrying out the present invention will be described in detail below. In the following description, the numerical range "x~y" includes x and y, meaning that "x~y" means "from x to y". In this specification, the term "(meth)acrylic" means both "acrylic" and "methacrylic". Similarly, the term "(meth)acrylate" means both "acrylate" and "methacrylate", and the term "(meth)acryloyl" means both "acryloyl" and "methacryloyl".

[0024] <Overall Structure> A dental adhesive composition according to one embodiment of the present invention (hereinafter simply referred to as the adhesive composition) can be used to repair teeth damaged by caries or the like. More specifically, the adhesive composition can be used to bond a dental filling material (hereinafter simply referred to as the filling material) to the tooth structure that constitutes the surface of the damaged area.

[0025] The dental adhesive composition according to this embodiment is configured as a one-component type and contains (a1) a polymerizable monomer containing an acidic group-containing polymerizable monomer (A), (B) a liquid polymer containing a radical polymerizable group, (C) a photopolymerization initiator, (D) water, and (E) an organic solvent.

[0026] In this embodiment, the adhesive composition containing the polymer allows the filling material to fill concave damaged areas of a tooth without curing the adhesive composition. Figure 1 is a schematic partial cross-sectional view showing the state in which the filling material has been filled into the damaged area of ​​a tooth via the adhesive composition. In the state shown in Figure 1, the uncured adhesive composition and the uncured filling material are in direct contact.

[0027] When light irradiation is performed to cure the filler material from the state shown in Figure 1, a portion of the irradiated light that passes through the filler material enters the adhesive composition, and photopolymerization-type curing proceeds.

[0028] In typical light-curing dental adhesives, adhesive components are contained as monomers, and in order to obtain high adhesive strength, it is necessary to supply a sufficient amount of radicals to adequately polymerize and cure the various monomers. In such adhesives, if polymerization is carried out using irradiation light that has passed through the filler material, the radicals from the photopolymerization initiator are insufficient in the interior where light does not easily reach, resulting in the presence of residual monomers and a decrease in adhesive strength. In contrast, in the dental adhesive composition of the present invention, even in an environment with insufficient radicals, the monomer polymerizes with the (B) radical polymerizable group-containing liquid polymer, causing a rapid increase in molecular weight and hardening. Therefore, it is possible to sufficiently harden the monomer in the adhesive composition by irradiation light that has passed through the filler material.

[0029] The adhesive composition according to this embodiment is not a specially constructed filling material, but is widely applicable to general light-curing filling materials, and can be used as a one-component, light-curing-free dental adhesive.

[0030] Therefore, since the adhesive composition according to this embodiment can be cured quickly and sufficiently, an adhesive layer with high adhesive strength can be obtained while minimizing the burden on the patient.

[0031] <Detailed Configuration> A dental adhesive composition according to one embodiment of the present invention is configured as a so-called one-component type, containing (A) a polymerizable monomer, (B) a liquid polymer containing radical polymerizable groups, (C) a photopolymerization initiator, (D) a solvent, and (E) water.

[0032] [(A) Polymerizable monomers] (A) The polymerizable monomer is a compound having at least one radical polymerizable unsaturated group in one molecule. In the adhesive composition according to this embodiment, curing occurs by radical polymerization of the polymerizable monomer (A). The polymerizable monomer (A) includes at least (a1) an acidic group-containing polymerizable monomer.

[0033] (a1) Acid group-containing polymerizable monomer (a1) The acidic group-containing polymerizable monomer is a monomer that can copolymerize with the (B) radical polymerizable group-containing liquid polymer described later by light irradiation, and is composed of an acidic polymerizable monomer containing at least one acidic group in addition to a polymerizable unsaturated group in one molecule. (a1) The acidic group-containing polymerizable monomer has a demineralizing effect on tooth structure and acts as an adhesive component to tooth structure, thereby improving the adhesion of the filling material to tooth structure.

[0034] In the adhesive composition according to this embodiment, when (A) polymerizable monomer is 100 parts by mass, the blending ratio of (a1) acidic group-containing polymerizable monomer is preferably 1 to 40 parts by mass, 5 to 35 parts by mass, and more preferably 10 to 30 parts by mass. This makes it easier to obtain sufficient adhesive strength to tooth structure and high adhesive durability in the adhesive composition.

[0035] (a1) Examples of polymerizable unsaturated groups contained in the acidic group-containing polymerizable monomer include acryloyl group, methacryloyl group, acrylamide group, methacrylamide group, and styryl group. Among these, from the viewpoint of adhesion to the filler material, the polymerizable unsaturated group is preferably an acryloyl group and / or a methacryloyl group.

[0036] (a1) The acidic groups contained in the polymerizable monomer containing the acidic group are groups that cause the aqueous dispersion medium or aqueous suspension of the polymerizable monomer having the acidic group, and are typically dihydrogen phosphate monoester group {-OP(=O)(OH)2}, hydrogen phosphate diester group {(-O-)2P(=O)OH}, carboxyl group (-COOH), phosphono group {-P(=O)(OH)2}, sulfo group (-SO3H), phosphinico group {=P(=O)OH}, acid anhydride group {-C(=O)-OC(=O)-}, and acid halide group {-C(=O)X, where X represents a halogen atom}. As a result, when cured by light irradiation, (a1) the polymerizable monomer containing the acidic group and (B) the liquid polymer containing the radical polymerizable group copolymerize well, and an adhesive layer with high adhesive strength is obtained.

[0037] Because it has high stability against water and can slowly dissolve the smear layer on the tooth surface and demineralize the tooth, it is preferable that the acidic group is a compound having a dihydrogen phosphate monoester group, a hydrogen phosphate diester group, and / or a carboxyl group, and it is most preferable that the acidic group is a compound having a dihydrogen phosphate monoester group and / or a hydrogen phosphate diester group.

[0038] Examples of acid monomers that can be suitably used include those having a dihydrogen phosphate monoester group or a hydrogen phosphate diester group, such as 2-(meth)acryloyloxyethylphenylhydrogen phosphate, 6-(meth)acryloyloxyhexyl dihydrogen phosphate, 6-(meth)acryloyloxyhexylphenylhydrogen phosphate, 10-(meth)acryloyloxydecyl dihydrogen phosphate, mono(2-methacryloxyethyl) acid phosphate, bis(2-methacryloxyethyl) acid phosphate, 1,3-di(meth)acryloylpropane-2-dihydrogen phosphate, 1,3-di(meth)acryloylpropane-2-phenylhydrogen phosphate, and bis[5-{2-(meth)acryloyloxyethoxycarbonyl}heptyl]hydrogen phosphate.

[0039] Furthermore, examples of acid monomers having a carboxyl group include acrylic acid, methacrylic acid, 4-(meth)acryloxyethyl trimellitic acid, 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.

[0040] Examples of acid monomers having a phosphono group include 3-(meth)acryloyloxypropylphosphonic acid, 6-(meth)acryloylhexylphosphonic acid, and 10-(meth)acryloyloxydecylphosphonic acid.

[0041] Examples of acid monomers having a sulfo group include 2-methacrylamide-2-methylpropanesulfonic acid, 2-acrylamido-2-methylpropanesulfonic acid, p-vinylbenzenesulfonic acid, and vinylsulfonic acid.

[0042] These acid monomers can be used individually or in combination.

[0043] ·(a2) Acidic group-free polymerizable monomer (A) From the viewpoint of adhesion to tooth structure and adhesive durability in the adhesive composition, the polymerizable monomer preferably further comprises (a1) an acidic group-containing polymerizable monomer and (a2) an acidic group-free polymerizable monomer that does not contain an acidic group.

[0044] (a2) The polymerizable monomer without acidic groups can be any known compound without particular limitations, as long as it does not contain acidic groups in one molecule and contains one or more polymerizable unsaturated groups. Here, the polymerizable unsaturated groups can be the same as those contained in (a1) the polymerizable monomer containing acidic groups, but from the viewpoint of adhesion, acryloyl groups, methacryloyl groups, acrylamide groups, methacrylamide groups, etc. are preferred.

[0045] (a2) Suitable specific examples of polymerizable monomers that do not contain acidic groups include, for example, monofunctional polymerizable monomers such as methyl (meth)acrylate, ethyl (meth)acrylate, butyl (meth)acrylate, glycidyl (meth)acrylate, 2-cyanomethyl (meth)acrylate, benzyl methacrylate, polyethylene glycol mono(meth)acrylate, allyl (meth)acrylate, 2-hydroxyethyl (meth)acrylate, 3-hydroxypropyl (meth)acrylate, glyceryl mono(meth)acrylate; ethylene glycol di(meth)acrylate; 2,2'-Bis[4-(meth)acryloyloxyethoxyphenyl]propane, 2,2'-Bis[4-(meth)acryloyloxyethoxyethoxyphenyl]propane, 2,2'-Bis[4-(meth)acryloyloxyethoxyethoxyphenyl]propane, 2,2'-Bis[4-(meth)acryloyloxyethoxyethoxyethoxyphenyl]propane [L]propane, 2,2'-bis{4-[2-hydroxy-3-(meth)acryloyloxypropoxy]phenyl}propane, 1,4-butanediol di(meth)acrylate, 1,6-hexanediol di(meth)acrylate, 1,9-nonanediol di(meth)acrylate, trimethylolpropane tri(meth)acrylate, neopentyl glycol di(meth)acrylate, 1,6-bis(methacrylateethyloxycarbonylamino)-2,2,4-trimethylhexane, 1,6-bis(methacrylateethyloxycarbonylamino)- Examples include polyfunctional polymerizable monomers such as 2,4,4-trimethylhexane, urethane di(meth)acrylate, epoxy di(meth)acrylate, and pentaerythritol tetramethacrylate; fumarate ester compounds such as monomethyl fumarate, diethyl fumarate, and diphenyl fumarate; styrene and α-methylstyrene derivatives such as styrene, divinylbenzene, α-methylstyrene, and α-methylstyrene dimer; and allyl compounds such as diallyl phthalate, diallyl terephthalate, diallyl carbonate, and allyl diglycol carbonate.In particular, it is preferable to include monofunctional polymerizable monomers from the viewpoint of penetration into tooth structure and compatibility of each component, and it is preferable to include polyfunctional polymerizable monomers from the viewpoint of improving mechanical strength and durability.

[0046] Specific examples of monofunctional polymerizable monomers that are preferably used include methyl (meth)acrylate, ethyl (meth)acrylate, glycidyl (meth)acrylate, 2-hydroxyethyl (meth)acrylate, 3-hydroxypropyl (meth)acrylate, and glyceryl mono(meth)acrylate.

[0047] Specific examples of polyfunctional polymerizable monomers that are preferably used include ethylene glycol di(meth)acrylate, 2,2'-bis{4-[2-hydroxy-3-(meth)acryloyloxypropoxy]phenyl}propane, triethylene glycol dimethacrylate, 2,2-bis[(4-(meth)acryloyloxypolyethoxyphenyl)propane], 1,6-bis(methacrylateethyloxycarbonylamino)-2,2,4-trimethylhexane, 1,6-bis(methacrylateethyloxycarbonylamino)-2,4,4-trimethylhexane, and trimethylolpropane trimethacrylate.

[0048] (a2) The polymerizable monomer without acidic groups may be used alone or in combination of two or more types. (a2) The polymerizable monomer without acidic groups may be used alone or in combination of two or more types. When using two or more types in combination, the proportion of the polymerizable monomer without acidic groups (a2) shall be based on the total mass of the polymerizable monomers (A).

[0049] (a2) The proportion of the polymerizable monomer that does not contain acidic groups is not particularly limited, but it is the amount obtained by subtracting the polymerizable monomer that contains acidic groups (a1) from 100 parts by mass of polymerizable monomer (A). From the viewpoint of ensuring sufficient adhesion improvement effect derived from polymerizable monomer that contains acidic groups (a1), the proportion of the polymerizable monomer that does not contain acidic groups (a2) is preferably 60 to 99 parts by mass, 75 to 95 parts by mass, and more preferably 70 to 90 parts by mass, per 100 parts by mass of polymerizable monomer (A).

[0050] [(B) Liquid polymer containing radical polymerizable groups] The radical polymerizable group-containing liquid polymer of one embodiment of the present invention (hereinafter also simply referred to as "(B) polymer") is a liquid polymer containing radically polymerizable unsaturated groups. Liquid means having the property of being fluid at room temperature (15-30°C). That is, the polymer according to this embodiment is typically not solid but has the property of flowing in an amorphous manner. Because (B) polymer is liquid, its penetration into the tooth surface and compatibility with the monomer of the filling material are improved, and good adhesion to the tooth surface and the filling material can be achieved. In the adhesive composition according to this embodiment, curing occurs not only through the curing of the filler material by light irradiation, but also through the radical polymerization of the radical polymerizable groups of the polymer (B). Furthermore, high molecular weight polymers such as polylower (meth)acrylates, which are generally included in dental adhesive compositions, are soluble in acetone but have low solubility in highly hydrophilic ethanol, resulting in uneven dispersion and insufficient adhesive strength. On the other hand, (B) the radical polymerizable group-containing liquid polymer shows good solubility in ethanol and achieves high adhesive strength through uniform dispersion. The adhesive composition according to this embodiment can use ethanol, which has low toxicity to the body, and is suitable for use in treatment.

[0051] (B) The blending ratio of the radical polymerizable group-containing liquid polymer is 0.1 to 50 parts by mass, preferably 1 to 20 parts by mass, per 100 parts by mass of (A) polymerizable monomer. By satisfying this range, the dental adhesive composition can exhibit high curability and adhesion to filling materials.

[0052] The radical polymerizable group-containing liquid polymer of one embodiment of the present invention preferably has structural unit (X), structural unit (Y), and structural unit (Z). The structural units (X) to (Z) will be explained below.

[0053] • Structural unit (X) Structural unit (X) is represented by the following general formula (1) and is derived from a (meth)acrylic monomer having a radically polymerizable unsaturated group. Structural unit (X) polymerizes with monomers in dental adhesive compositions and filling materials by radical polymerization, improving the curability of dental adhesive compositions and their adhesion to filling and restorative materials. [ka] (In general formula (1), R 1 and R 2 (where n represents a hydrogen atom or a methyl group, and n is an integer from 1 to 15.)

[0054] From the viewpoint of the curability of the dental adhesive composition and its adhesion to the filling and restorative material, the content of structural unit (X) is preferably 5 to 80 mol%, and particularly preferably 20 to 80 mol%, per 100 mol% of the radical polymerizable group-containing liquid polymer.

[0055] Structural units (X) can be obtained, for example, by synthesis methods I and II described below. Synthesis method I is preferred to ensure the reliable acquisition of structural units (X).

[0056] In synthesis method I, a polymer synthesized using a (meth)acrylate represented by the following general formula (4) or (5) as one of the copolymerization components is reacted with a base to abstract a proton and remove E, thereby obtaining structural unit (X). [ka] (In general formulas (4) and (5), E represents an anionic leaving group, and R 6 , R 7 , R 8 and R 9 (where 'p' represents a hydrogen atom or a methyl group, and 'q' represents an integer between 1 and 15.)

[0057] Preferred anionic leaving groups include halogen atoms, alkyl or arylsulfonyloxy groups, and particularly preferred are bromine atoms, chlorine atoms, and p-toluenesulfonyloxy groups. Specifically, due to the ease of obtaining the raw materials for synthesis, examples include 2-((3-bromo-2-methylpropanoyl)oxy)ethyl methacrylate, 2-((3-bromo-2-methylpropanoyl)oxy)ethyl acrylate, 2-((3-bromopropanoyl)oxy)ethyl methacrylate, 2-((3-chloro-2-methylpropanoyl)oxy)ethyl methacrylate, 2-((3-chloro-2-methylpropanoyl)oxy)ethyl acrylate, and 2-((3-chloropropanoyl)oxy)ethyl methacrylate.

[0058] Either an inorganic base or an organic base may be used as the base that induces the elimination reaction. Preferred inorganic compound bases include sodium hydroxide, potassium hydroxide, sodium carbonate, sodium bicarbonate, potassium carbonate, and potassium bicarbonate. Organic compound bases include metal alkoxides such as sodium methoxide, sodium ethoxide, and potassium t-butoxide, as well as organic amine compounds such as triethylamine, pyridine, and diisopropylethylamine.

[0059] In synthesis method II, a polymer synthesized using a (meth)acrylate containing a hydroxyl group as one of the copolymerization components is reacted with (meth)acrylate chloride or (meth)acrylate anhydride to obtain structural unit (X).

[0060] • Structural unit (Y) The structural unit (Y) is represented by the following general formula (2) and is a structural unit derived from a (meth)acrylic monomer having an alkyl group, the alkyl group may also contain an ethylene glycol chain. By including structural unit (Y), the compatibility with tooth structure and filling material can be improved, improving penetration into the tooth surface and compatibility with the monomer of the filling material, and forming an adhesive layer with good adhesion to the tooth surface and filling material. [ka] (In general formula (2), R 3 R represents a hydrogen atom or a methyl group. 4 This represents a group with a total of 1 to 15 carbon atoms, as shown in the general formula (2-1) below. [ka] (In the above formula, p represents an integer between 0 and 5, and R' represents an alkyl group.)

[0061] The content of structural unit (Y) is preferably 15 to 90 mol%, and particularly preferably 20 to 80 parts by mass, based on 100 mol% of the radical polymerizable group-containing liquid polymer, from the viewpoint of penetration into the tooth surface and compatibility with the filling material.

[0062] From the viewpoint of further improving penetration into the tooth surface and compatibility with the monomer of the filling material, in general formula (2), R 3 If R is a hydrogen atom, 4 R is a group with a total number of carbon atoms of 1 to 15. 3 If R is a methyl group, 4 Preferably, the group has a total of 4 to 15 carbon atoms. This allows the polymer according to this embodiment to be in a liquid state with appropriate fluidity, improving adhesion to the tooth surface and filling material.

[0063] In particular, from the viewpoint of making the polymer liquid, it is preferable that the structural unit (Y) represented by general formula (2) is a structure derived from a monomer selected from methyl acrylate, ethyl acrylate, propyl acrylate, butyl (meth)acrylate, pentyl (meth)acrylate, hexyl (meth)acrylate, heptyl (meth)acrylate, octyl (meth)acrylate, nonyl (meth)acrylate, decyl (meth)acrylate, undecyl (meth)acrylate, dodecyl (meth)acrylate, 2-methoxyethyl (meth)acrylate, 2-ethoxyethyl (meth)acrylate, and 2-(2-methoxyethoxy)ethyl (meth)acrylate.

[0064] • Structural unit (Z) The structural unit (Z) is represented by the following general formula (3) and is a structure derived from a (meth)acrylic monomer containing an acidic group. The acidic group L of (Z) has a demineralizing effect on tooth structure and also acts as an adhesive component to tooth structure, thereby improving the adhesion of the filling material to tooth structure. In other words, structural unit (Z) has the same effect as the acidic group-containing polymerizable monomer described above (a1). Since structural unit (Z) can be formed by copolymerization with the acidic group-containing polymerizable monomer (a1) during the curing of the adhesive composition, the (B) radical polymerizable group-containing liquid polymer does not need to contain structural unit (Z) and may consist only of structural units (X) and (Y). [ka] (In general formula (3), R 5 (where '' represents a hydrogen atom or a methyl group, L represents a dihydrogen phosphate monoester group {-OP(=O)(OH)2} or a phosphono group {-P(=O)(OH)2}, and m represents an integer from 1 to 15.)

[0065] From the viewpoint of obtaining high adhesion to the tooth surface and high adhesive durability, the content of structural unit (Z) is preferably 0 to 50 mol%, more preferably 5 to 50 mol%, and particularly preferably 10 to 40 mol%, per 100 mol% of the (B) radical polymerizable group-containing liquid polymer.

[0066] Because it has high stability against water and allows for gradual dissolution of the smear layer on the tooth surface and demineralization of the tooth, it is preferable that L is a dihydrogen phosphate monoester group {-OP(=O)(OH)2}.

[0067] Specific examples of structural units (Z) having a dihydrogen phosphate monoester group include 2-(phosphonooxy)ethyl methacrylate, 6-(meth)acryloyloxyhexyl dihydrogen phosphate, and 10-(meth)acryloyloxydecyl dihydrogen phosphate.

[0068] Specific examples of structural units (Z) having a phosphono group include 3-(meth)acryloyloxypropylphosphonic acid, 6-(meth)acryloylhexylphosphonic acid, and 10-(meth)acryloyloxydecylphosphonic acid.

[0069] (Molecular weight of polymer) The weight-average molecular weight of the radical polymerizable group-containing liquid polymer of one embodiment of the present invention is preferably 1,000 to 50,000, and more preferably 2,000 to 20,000. The weight-average molecular weight is measured by gel permeation chromatography (GPC) using styrene as a standard. Having a weight-average molecular weight within the above range results in an appropriate viscosity, and when applied to the tooth surface as a dental adhesive material, the applied film does not run, making it easier to operate during dental treatment. Furthermore, the desired thickness can be secured after application, and even when air blowing is performed to remove the solvent after application, the film remains uniform, resulting in the formation of an adhesive layer with high adhesive strength.

[0070] [(C) Photopolymerization initiator] (C) The photopolymerization initiator is a compound that initiates the radical polymerization of (A) the polymerizable monomer upon light irradiation. This makes it possible to advance photopolymerization-type curing in the adhesive composition according to this embodiment.

[0071] For example, (C) as a photopolymerization initiator, α-diketones such as camphorquinone or acylphosphine oxides can be used.

[0072] In particular, the adhesive composition preferably contains (c1) bisacylphosphine oxide as (C) a photopolymerization initiator.

[0073] • (c1) Bisylphosphone oxide (c1) Bisacylphosphine oxide is a monomolecule-cleaving, highly active photopolymerization initiator. Therefore, (c1) bisacylphosphine oxide is also affected by a small amount of light. (A) Photopolymerization of polymerizable monomers can be promoted. (c1) The blending ratio of bisacylphosphine oxide is preferably 0.1 to 10 parts by mass, and more preferably 0.5 to 8 parts by mass, per 100 parts by mass of polymerizable monomer (A). By satisfying this range, high polymerization activity and adhesion can be achieved. (c1) Bisacylphosphine oxide is a compound represented by the following formula.

[0074] [ka]

[0075] In the above formula, R C1 R represents an alkyl group, alkenyl group, alkynyl group, aryl group, alkoxy group, acyl group, or acyloxy group. C2 ~R C11 Each of these independently represents a hydrogen atom, a halogen atom, an alkyl group, an alkenyl group, an alkynyl group, an aryl group, an alkoxy group, an acyl group, or an acyloxy group.

[0076] Examples of (c1) bisacylphosphine oxides represented by the formula 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 (2,5,6-trimethylbenzoyl)-2,4,4-trimethylpentylphosphine oxide. (c1) The bisacylphosphine oxide includes the bisacylphosphine oxides and their derivatives as described above.

[0077] [(D)Water] The water used is preferably substantially free of impurities that are harmful from the viewpoint of storage stability, biocompatibility, and adhesion. Examples of usable water include deionized water and distilled water. The proportion of water used is preferably 1 to 50 parts by mass, and more preferably 10 to 20 parts by mass, per 100 parts by mass of polymerizable monomer (A).

[0078] [(E) Organic solvents] Any known organic solvent can be used without restriction as the organic solvent, but it is generally preferable to use a highly volatile organic solvent with a boiling point of less than 100°C. The mixing ratio of the organic solvent is preferably 10 to 300 parts by mass, and more preferably 30 to 200 parts by mass, per 100 parts by mass of (A) polymerizable monomer.

[0079] Specifically, examples of organic solvents include alcohols such as methanol, ethanol, isopropyl alcohol, and butanol; ketones such as acetone and methyl ethyl ketone; ethers such as ethyl ether, 1,4-dioxane, and tetrahydrofuran; esters such as ethyl acetate and ethyl formate; aromatic solvents such as toluene, xylene, and benzene; hydrocarbon solvents such as pentane, hexane, heptane, and octane; chlorinated solvents such as methylene chloride, chloroform, and 1,2-dichloroethane; and fluorinated solvents such as trifluoroethanol. Among these, acetone, ethanol, and isopropyl alcohol are particularly preferred for reasons such as biocompatibility, solubility, and storage stability. One or more organic solvents can be used in combination.

[0080] [Other ingredients] The adhesive composition may contain various additives other than those listed above, as needed. Examples of additives include (F) fillers, polymerization inhibitors, chemical polymerization initiators, polyvalent metal compounds, colorants, and photopolymerization accelerators, with the inclusion of fillers and polymerization inhibitors being particularly preferred.

[0081] (F) Filler Fillers are added to improve the mechanical strength and workability of the adhesive layer obtained by curing the adhesive composition. There are no particular limitations on the filler, and known inorganic fillers, organic fillers, and inorganic-organic composite fillers can be used.

[0082] Examples of inorganic fillers include quartz, amorphous silica, fumed silica, silica zirconia, clay, aluminum oxide, talc, mica, kaolin, glass, barium sulfate, zirconium oxide, titanium oxide, silicon nitride, aluminum nitride, titanium nitride, silicon carbide, boron carbide, calcium carbonate, hydroxyapatite, and calcium phosphate. Furthermore, it is preferable to surface treat these inorganic fillers. This improves their compatibility with polymerizable monomers, making it easier to enhance mechanical strength and water resistance. The surface treatment method can be any known method, and suitable surface treatment agents include methyltrimethoxysilane, methyltriethoxysilane, methyltrichlorosilane, dimethyldichlorosilane, trimethylchlorosilane, vinyltrimethoxysilane, vinyltriethoxysilane, vinyltrichlorosilane, vinyltriacetoxysilane, vinyltris(β-methoxyethoxy)silane, γ-methacryloyloxypropyltrimethoxysilane, γ-methacryloyloxypropyltris(β-methoxyethoxy)silane, γ-chloropropyltrimethoxysilane, γ-chloropropylmethyldimethoxysilane, γ-glycidoxypropyltrimethoxysilane, γ-glycidoxypropylmethyldiethoxysilane, β-(3,4-epoxycyclohexyl)ethyltrimethoxysilane, N-phenyl-γ-aminopropyltrimethoxysilane, hexamethyldisilazane, and the like.

[0083] As an inorganic filler, fumed silica is more preferable. This allows for an adhesive layer with higher adhesive strength after curing. The average primary particle size of the fumed silica is preferably 1 nm to 20 nm. Thus, by using fumed silica with a small average primary particle size in the adhesive composition, the fumed silica is less likely to settle even when the amount added is increased. Therefore, by increasing the amount of fumed silica added to the adhesive composition, it is possible to form an adhesive layer with even higher adhesive strength.

[0084] When incorporating inorganic fillers, the amount is preferably 10 to 30 parts by mass per 100 parts by mass of polymerizable monomer (A). Using 10 parts by mass or more provides higher adhesive strength, while using 30 parts by mass or less ensures adequate fluidity for a dental adhesive, resulting in excellent handling properties.

[0085] Based on the above, it is even more preferable that the adhesive composition according to this embodiment contains 10 to 30 parts by mass of fumed silica having an average primary particle diameter of 1 nm to 20 nm per 100 parts by mass of polymerizable monomer (A). This makes it possible to form an adhesive layer with even higher adhesive strength.

[0086] In addition, the adhesive composition may contain polymers other than (B) radical polymerizable group-containing liquid polymers as organic fillers. Examples of organic fillers include non-crosslinkable polymers such as polymethyl (meth)acrylate, polyethyl (meth)acrylate, methyl (meth)acrylate-ethyl (meth)acrylate copolymer, methyl (meth)acrylate-butyl (meth)acrylate copolymer, methyl (meth)acrylate-styrene copolymer, or (meth)acrylate polymers such as methyl (meth)acrylate-ethylene glycol di(meth)acrylate copolymer, methyl (meth)acrylate-triethylene glycol di(meth)acrylate copolymer, and copolymer of methyl (meth)acrylate and butadiene monomers.

[0087] When an organic filler is added, the amount added is preferably 0.01 to 10 parts by mass per 100 parts by mass of (A) polymerizable monomer.

[0088] Furthermore, the substances listed above may be used individually as fillers, or two or more may be used in combination.

[0089] • Polymerization inhibitors The dental adhesive composition of this embodiment, which includes a polymerization initiator and a polymerizable monomer, may also contain known polymerization inhibitors that can be used in general dental materials, if necessary. This suppresses the progression of the polymerization reaction during storage of the adhesive composition, allowing for stable long-term storage. Examples of polymerization inhibitors include hydroquinone, hydroquinone monomethyl ether, and dibutylhydroxytoluene. The polymerization inhibitors listed above may be used individually or in combination of two or more. The amount of polymerization inhibitor added is preferably 0.0001 to 10 parts by mass per 100 parts by mass of polymerizable monomer (A) contained in the dental adhesive composition. • Photopolymerization accelerator It is preferable to use the above-mentioned photopolymerization initiator in combination with a photopolymerization accelerator. Aromatic tertiary amine compounds are preferably used as such photopolymerization accelerators. Examples of aromatic tertiary amine compounds include 4-dimethylaminobenzoic acid, ethyl 4-dimethylaminobenzoate, lauryl 4-dimethylaminobenzoate, 3-dimethylaminobenzoic acid, ethyl 3-dimethylaminobenzoate, dimethylamino-p-toluidine, diethylamino-p-toluidine, and p-tolyldiethanolamine. The substances listed above may be used individually or in combination of two or more as photopolymerization accelerators. The amount of photopolymerization accelerator added is preferably 0.1 to 10 parts by mass per 100 parts by mass of polymerizable monomer (A) contained in the dental adhesive composition. [Examples]

[0090] The present invention will be described below with reference to examples, but the present invention is not limited in any way to the following examples.

[0091] <Abbreviation for substance> First, the abbreviations for the substances used in the examples and comparative examples are explained below. [(A) Polymerizable monomers] (a1) Acid group-containing polymerizable monomer MDP:10-Methacrylate oxydecyl dihydrogen phosphate SPM: A 1:2 mixture of mono(2-methacryloxyethyl) acid phosphate and bis(2-methacryloxyethyl) acid phosphate. ·(a2) Acidic group-free polymerizable monomer HEMA: 2-hydroxyethyl methacrylate 3G: Triethylene glycol dimethacrylate Bis-GMA: 2,2'-Bis{4-[2-hydroxy-3-(meth)acryloyloxypropoxy]phenyl}propane [(B) Liquid polymer containing radical polymerizable groups] The following shows the compounds used in the synthesis of (B) liquid polymers containing radical polymerizable groups. • Monomer of structural unit (X) BrMPMA:2-((3-bromo-2-methylpropanoyl)oxy)ethyl methacrylate BrMPA: 2-((3-bromo-2-methylpropanoyl)oxy)ethyl acrylate BrPMA: 2-((3-bromopropanoyl)oxy)ethyl methacrylate • Monomers of structural unit (Y) MA: Methyl acrylate (manufactured by Tokyo Chemical Industry Co., Ltd.) DMA: Dodecyl methacrylate (manufactured by Tokyo Chemical Industry Co., Ltd.) TDMA: Tridecyl methacrylate (manufactured by Tokyo Chemical Industry Co., Ltd.) MMA: Methyl methacrylate (manufactured by Tokyo Chemical Industry Co., Ltd.) • Monomers of structural units (Z) PM1:2-(phosphonoxy)ethyl methacrylate (P-1M (manufactured by Kyoeisha Chemical Co., Ltd.) purified with water / dichloromethane) PA1:2-(phosphonooxy)ethyl acrylate (P-1A (manufactured by Kyoeisha Chemical Co., Ltd.) purified with water / dichloromethane) Other compounds used THF: Tetrahydrofuran (manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.) TEA: Triethylamine (manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.) DIPE: Diisopropyl ether (manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.) AIBN: Azovis (isobutyronitrile) (manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.) [(C) Photopolymerization initiator] BTPO: Phenylbis(2,4,6-trimethylbenzoyl)phosphine oxide CQ: Camphorquinone [Other ingredients] (F) Filler DM-30: Average primary particle size of 7 nm, dimethyldichlorosilane-treated silica particles (manufactured by Tokuyama Corporation) DM-20: Average primary particle size 12 nm, surface treatment agent: dimethyldichlorosilane (manufactured by Tokuyama Corporation) • Polymerization inhibitors BHT: Dibutylhydroxytoluene • Photopolymerization accelerator DMBE: 4-Dimethylaminobenzoate ethyl Other polymers PMMA: Polymethyl methacrylate (weight-average molecular weight 1,000,000)

[0092] <(B) Radical polymerizable group-containing liquid polymers P1-P7 and reference polymer P8> [(B) Synthesis of a radical polymerizable liquid polymer and reference polymer P8] (B) Radical polymerizable group-containing liquid polymers P1 to P7 and reference polymer P8 (hereinafter also simply referred to as "polymers P1 to P8," etc.) were synthesized by the following method. The components and blending ratios of each polymer are shown in Table 1 below.

[0093] First, we synthesized the monomer of structural unit (X). 1.7 g (15 mmol) of 3-bromoisobutyric acid (manufactured by Tokyo Chemical Industry Co., Ltd.) was weighed into a 200 mL pear-shaped flask. 100 mL of THF was then added, followed by 3.5 g (18 mmol) of 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide (manufactured by Tokyo Chemical Industry Co., Ltd.), 0.1 g (1 mmol) of 4-dimethylaminopyridine (manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.), and 1.3 g (10 mmol) of 2-hydroxyethyl acrylate (manufactured by Shin-Nakamura Chemical Industry Co., Ltd.). After 6 hours, the medium was removed using an evaporator, and ethyl acetate (100 mL) was added. The ethyl acetate layer was washed three times with water (100 mL). Magnesium sulfate was added to the ethyl acetate layer and dried, and the ethyl acetate was removed under reduced pressure using an evaporator. The resulting compound was dried at 80°C for 1 hour with oxygen bubbling to obtain BrMPMA; 2.2 g, in 75% yield. In addition, when synthesizing BrMPA, 2-hydroxyethyl acrylate (manufactured by Tokyo Chemical Industry Co., Ltd.) was used instead of 2-hydroxyethyl methacrylate.

[0094] Next, polymers P1 to P8 were synthesized using the following method. (1) Polymer P1 was synthesized by synthesis method (i). First, the polymerizable precursor polymer P1' was synthesized as shown in the following reaction equation. BrMPA; 266 mg (1 mmol), PA1; 588 mg (3 mmol), and AIBN; 164 mg (1 mmol) were weighed into a 100 mL pear-shaped flask. After purging with nitrogen, 20 mL of THF / water (8 / 2) mixed solvent was added, followed by the addition of MA; 537 μl (6 mmol) to the system. The mixture was heated and stirred at 65°C for 24 hours using an oil bath. Monomer disappearance was confirmed by HPLC, and THF was removed under reduced pressure using an evaporator. The resulting crude product was reprecipitation under an ethanol / dry ice bath using 20 mL of DIPE / THF (9 / 1) mixed solvent, followed by vacuum drying to obtain polymerizable group precursor polymer P1'. [ka]

[0095] Next, polymer P1 was synthesized. Polymerizable precursor polymer P1' was dissolved in 20 mL of dichloromethane, and 2 mL of TEA was added. After stirring at room temperature for 6 hours, 20 mL of 1N hydrochloric acid was added and a washing procedure was performed. The dichloromethane layer was washed twice more with 20 mL of 1N hydrochloric acid. The dichloromethane layer was dried with magnesium sulfate, and the dichloromethane was removed by vacuum distillation and vacuum drying using an evaporator to obtain 1.09 g (yield 85%) of polymer P1. 1 ¹H-NMR measurements revealed the composition ratio to be structural unit (X) (mol%):structural unit (Y) (mol%):structural unit (Z) (mol%) = 10:59:31 (=x:y:z), and GPC measurements showed a weight-average molecular weight Mw = 4200.

[0096] (2) Polymer P2 was synthesized by synthesis method (ii). First, the polymerizable precursor polymer P2' was synthesized as shown in the following reaction equation. AIBN; 164 mg (1 mmol) was weighed into a 100 mL pear-shaped flask. After purging with nitrogen, 15 mL of THF / water (8 / 2) mixed solvent was added, followed by MA; 538 μl (6 mmol) was added to the system. The reaction system was then heated to 65°C using an oil bath. A 5 mL solution of PM1; 210 mg (1 mmol) and BrMPMA; 834 mg (3 mmol) in THF / water (8 / 2) mixed solvent was added dropwise over 3 hours using a syringe pump. After the addition was complete, the reaction was continued at 65°C for another 21 hours, and monomer disappearance was confirmed by HPLC. THF was removed under reduced pressure using an evaporator. The resulting crude product was reprecipitation in an ethanol / dry ice bath with 20 mL of diisopropyl ether / THF (8 / 2), followed by vacuum drying to obtain polymerizable group precursor polymer P2'. [ka]

[0097] Next, polymer P2 was synthesized. Using the same method as in Synthesis Method 1, the polymerizable group precursor polymer P2' was converted to polymer P2, yielding 1.08 g (82% yield) of P2. 1 ¹H-NMR measurements revealed the composition ratio to be structural units (X) (mol%):Y structural units (Y) (mol%):Z structural units (Z) (mol%) = 30:60:10 (=x:y:z), and GPC measurements showed a weight-average molecular weight Mw = 4300.

[0098] (3) Polymers P3 to P5 were synthesized using the same method as in synthesis method (i) or (ii). Due to the difference in copolymerization properties between methacrylate monomers and acrylate monomers, synthesis method (i) was used when only methacrylate monomer or acrylate monomer was used, and synthesis method (ii) was used when both methacrylate monomer and acrylate monomer were used. The monomers used, composition ratio, properties, weight-average molecular weight, and yield are shown in Table 2.

[0099] (4) Polymers P6 and P7 were synthesized by synthesis method (iii). Synthesis method (iii) was the same as synthesis method (i), except that AIBN; 82 mg (0.5 mmol) was used. [ka] (5) Polymer P8 was synthesized by synthesis method (i). Polymer P8 is a solid and is not an example of a (B) radical polymerizable group-containing liquid polymer of the present invention.

[0100] [(B) Analysis of liquid polymers containing radical polymerizable groups] Table 1 shows the properties, weight-average molecular weight, and yield of the obtained polymers. Because the polymers in this embodiment are obtained by converting polymerizable group precursors into polymerizable groups, there are no protection / deprotection steps, resulting in fewer steps. Therefore, there was less loss due to purification, and the yields were high in all cases. The weight-average molecular weight was measured by the following method.

[0101] ¹H-NMR measurement; a JEOL Ltd. JNM-ECAII (400MHz) was used as the measurement device. Deuterated chloroform was used as the measurement solvent, and the measurement sample was diluted 100-fold before measurement. GPC measurement was performed using an Advanced Polymer Chromatography system manufactured by Waters Corporation Japan. ACQUITY APCTMXT45 (1.7 μm) and ACQUITY APCTMXT125 (2.5 μm) columns were used, with a column temperature of 40°C. THF was used as the developing solvent at a flow rate of 0.5 ml / min. A 210 nm photodiode array detector was used. Additionally, THF was used as the measurement solvent, and the measurement sample was diluted 100-fold before measurement.

[0102] [Table 1]

[0103] <Examples 1-24 and Comparative Examples 1-8> Adhesive compositions were prepared for Examples 1-24 and Comparative Examples 1-8, and their adhesive strength was evaluated.

[0104] [Preparation of dental adhesive compositions] Adhesive compositions for Examples 1-24 and Comparative Examples 1-8 were prepared with the following compositions. The components and proportions of each adhesive composition are shown in Tables 2-4 below. In the tables, "↑" means "same as above".

[0105] [Evaluation of adhesive compositions] Next, the tensile adhesive strength of the obtained adhesive compositions was evaluated.

[0106] The adhesive strength to tooth structure was measured as follows. Bovine incisors extracted within 24 hours of slaughter were polished with water-resistant abrasive paper P600 under running water to prepare a substrate by grinding the dentin surface so that it was parallel and flat to the labial surface. Next, double-sided tape with a 3mm diameter hole was attached to the polished surface of the adherend. Subsequently, the dental adhesive composition prepared in each example and comparative example was applied to the adhesive surface exposed through the hole in the double-sided tape on the polished surface, and dried by air blowing for 5 seconds. A 0.5mm thick paraffin wax with an 8mm diameter hole was attached to the adhesive surface to which the dental adhesive composition had been applied, so that the hole in the paraffin wax and the hole in the double-sided tape were concentric, to create a simulated cavity. Dental composite resin (Estelite Universal Flow, manufactured by Tokuyama Dental Co., Ltd.) was filled into this simulated cavity and lightly pressed with a polyester film, and then photocuring was performed by light irradiation for 10 seconds using a visible light curing unit (Elliper, manufactured by 3M ESPE). After that, a pre-polished SUS304 round bar (8mm in diameter, 18mm in height) was bonded with resin cement (Estecem II, manufactured by Tokuyama Dental Co., Ltd.) to create an evaluation sample. The composite resin used is a photopolymerizable composition containing camphorquinone and an amine compound. After immersing the test sample in 37°C water for 24 hours, a load was applied to the test sample using a universal testing machine (AG-I type, manufactured by Shimadzu Corporation) at a crosshead speed of 1 mm / min until the sample fractured. The adhesive strength was then determined from the maximum load using the following formula. Adhesive strength (MPa) = maximum load (N) / adhesion area (mm) 2 ). Measurements were taken within approximately one day of removing the samples for adhesive strength measurement from the water. For each example and comparative example, the measurement values ​​of four samples were averaged to obtain the measurement results.

[0107] Examples 1 to 24 shown in Tables 2 and 3 use dental adhesive compositions formulated to satisfy the components of the present invention. In all cases, the adhesion test results were good.

[0108] The adhesive compositions in Comparative Examples 1 to 8 are examples in which each component does not satisfy the configuration shown in the present invention. The adhesive compositions of Comparative Examples 1 to 6 shown in Table 4 did not contain (a1) an acidic group-containing polymerizable monomer, (B) a radical polymerizable group-containing liquid polymer, (C) a photopolymerization initiator, or (D) water, respectively, and therefore it is thought that good adhesive strength could not be obtained. In addition, in Comparative Examples 3 and 4, a solid polymer was used instead of component (B), but it is thought that the adhesive composition did not adhere well to the tooth surface and showed low adhesive strength. In Comparative Example 7, the amount of component (B) was less than 0.1 parts by mass, so it is thought that the effect of the compound was not fully realized, and good adhesive strength could not be obtained. In Comparative Example 8, the amount of component (B) exceeded 50 parts by mass, so it is thought that the conformity with the tooth surface was reduced, and good adhesive strength could not be obtained.

[0109] [Table 2]

[0110] [Table 3]

[0111] [Table 4]

Claims

1. A one-component dental adhesive composition for bonding light-curing filling materials to tooth structure, 100 parts by mass of (A) polymerizable monomer containing 1 to 40 parts by mass of (a1) acidic group-containing polymerizable monomer, 0.1 to 50 parts by mass of (B) a liquid polymer containing radical polymerizable groups, 0.1 to 10 parts by mass of (C) photopolymerization initiator, 1 to 50 parts by mass of (D) water, 10 to 300 parts by mass of (E) organic solvent, It contains, The (B) radical polymerizable group-containing liquid polymer has fluid properties at room temperature (15-30°C) and has an acryloyl group and / or a methacryloyl group as the radical polymerizable group. Dental adhesive composition.

2. A dental adhesive composition according to claim 1, The (B) radical polymerizable group-containing liquid polymer comprises 5 to 80 mol% of structural unit (X) represented by the following general formula (1), 15 to 90 mol% of structural unit (Y) represented by the following general formula (2), and 0 to 50 mol% of structural unit (Z) represented by the following general formula (3). Dental adhesive composition. 【Chemistry 1】 (In general formula (1), R １ and R ２ (where n represents a hydrogen atom or a methyl group, and n is an integer from 1 to 15.) 【Chemistry 2】 (In general formula (2), R ３ R represents a hydrogen atom or a methyl group. 4 This represents a group with a total of 1 to 15 carbon atoms, as shown in the general formula (2-1) below. 【Transformation 3】 (In the above formula, p represents an integer from 0 to 5, and R' represents an alkyl group.) 【Chemistry 4】 (In general formula (3), R 5 represents a hydrogen atom or a methyl group, and L is a dihydrogen phosphate monoester group {-O-P(=O)(OH) ２ } or phosphono group {-P(=O)(OH) ２ } represents a number, where m is an integer between 1 and 15.

3. A dental adhesive composition according to claim 2, In the general formula (2), when R3 is a hydrogen atom, R 4 is a group having 1 to 15 carbon atoms in total, and when R3 is a methyl group, R 4 represents a group having 4 to 15 carbon atoms in total, Dental adhesive composition.

4. A dental adhesive composition according to claim 2 or 3, The (C) photopolymerization initiator comprises (c1) bisacylphosphine oxide. Dental adhesive composition.

5. A dental adhesive composition according to any one of claims 2 to 4, The (B) radical polymerizable group-containing liquid polymer contains 20 to 80 mol% of the structural unit (X) represented by the general formula (1). Dental adhesive composition.

6. A dental adhesive composition according to any one of claims 2 to 5, The (B) radical polymerizable group-containing liquid polymer contains 5 to 50 mol% of the structural unit (Z) represented by the general formula (3). Dental adhesive composition.

7. A dental adhesive composition according to any one of claims 2 to 6, The weight-average molecular weight of the (B) radical polymerizable group-containing liquid polymer, as measured by gel permeation chromatography (GPC) using styrene as a standard, is 1,000 or more and 50,000 or less. Dental adhesive composition.

8. A dental adhesive composition according to any one of claims 2 to 7, It further contains 10 to 30 parts by mass of fumed silica having an average primary particle size of 1 nm to 20 nm. Dental adhesive composition.

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