Dental adhesive composition

Abstract

To provide a 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 dental adhesive composition 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, 50 to 500 pts.mass of (C) an organic solvent, 1 to 50 pts.mass of (D) water and 0.1 to 30 pts.mass of (E) a chemical polymerization initiator.

Description

[Technical Field]

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

[0002] For restoring teeth damaged by caries, a hardening filling material called composite resin is used. Adhesion between the tooth structure and the filling material is crucial for caries restoration, but since the filling material itself has little adhesion to the tooth structure, dental bonding agents are usually used. Generally, widely known dental bonding agents achieve adhesion by hardening monomers (adhesive monomers and base monomers) with chemical polymerization initiators or photopolymerization initiators.

[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] As an adhesive that does not require light irradiation, chemical polymerization adhesives such as those described in Patent Document 2 are known. Chemical polymerization adhesives harden when the chemical polymerization initiator reacts after mixing the individually packaged components. Since the filler material can be filled immediately after mixing the components, treatment time can be shortened and the burden on the patient can be reduced. [Prior art documents] [Patent Documents]

[0006] [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. 2010-202625 [Overview of the Initiative] [Problems that the invention aims to solve]

[0007] On the other hand, chemically polymerized adhesives do not easily achieve sufficient bonding strength compared to light-polymerized dental adhesives. One reason for this is the low strength of the film after solvent removal. The film referred to here is the adhesive layer that is interposed between the adherends (two objects to be bonded together). If the strength of this film is weak, the adhesive components may peel off the bonding surface due to air blowing for solvent removal, or the adhesive components may be pushed out due to the pressure applied during bonding, causing the film to deform. This results in an uneven thickness of the film, making bonding failure more likely.

[0008] When using light-curing dental adhesives, polymerization occurs by light irradiation after application, improving the strength of the coating. This makes the coating less susceptible to the effects of air pressure from air blows and pressure from filling materials. On the other hand, when using chemically curing dental adhesives, polymerization proceeds more slowly compared to light-curing adhesives, making the coating more susceptible to the effects of air blows and pressure from the adherend. Therefore, there is a demand for chemically curing dental adhesives with high adhesive strength.

[0009] Patent Document 3 discloses a dental adhesive that uses poly-lower (meth)acrylate to form a strong adhesive layer of uniform thickness, thereby improving adhesive strength. However, the effect of poly-lower (meth)acrylate in improving adhesive strength is limited, and sufficient adhesive strength cannot always be obtained.

[0010] Furthermore, when the inventors investigated the effect of adding polylower (meth)acrylate, they found that the desired effect could not be obtained depending on the type of organic solvent used. Specifically, when ethanol was used as the organic solvent, it was found that even when the polymer exemplified in Patent Document 3 was incorporated, a uniform composition could not be obtained due to low solubility, and a good adhesive effect could not be obtained.

[0011] In view of the above circumstances, the object of the present invention is to provide a chemical polymerization type dental adhesive composition that exhibits good adhesion. [Means for solving the problem]

[0012] The inventors diligently conducted research to overcome the above technical challenges. As a result, the inventors discovered that while excessive amounts of polylower (meth)acrylate, being a non-polymerizable component, reduced the mechanical strength of the cured adhesive layer and limited the improvement of adhesive strength, a specific adhesive composition containing a radically polymerizable liquid polymer could provide excellent adhesion, thus completing the present invention. Furthermore, the liquid polymer containing radical polymerizable groups, possessing high biocompatibility, dissolves uniformly even in ethanol, which is frequently used, resulting in the discovery of a dental adhesive composition with superior product design advantages.

[0013] To achieve the above objective, a dental adhesive composition according to one embodiment of the present invention 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, 50 to 500 parts by mass of (C) organic solvent, 1 to 50 parts by mass of (D) water, and 0.1 to 30 parts by mass of (E) chemical polymerization initiator.

[0014] An adhesive composition according to one embodiment of the present invention is used as a two-component or multi-component adhesive that hardens when two or more components are mixed. In the dental adhesive composition according to an embodiment of the present invention, in the (A) polymeric monomer, the inclusion of the (a1) acidic group-containing polymeric monomer improves the adhesion to dentin. Further, since the (B) radical-polymerizable group-containing liquid polymer (hereinafter also simply referred to as "(B) polymer") contains a radical-polymerizable group, the curability of the dental adhesive composition and the adhesion to the filling material are improved. Further, since the (B) polymer is in a liquid state, it has better compatibility with dentin and the filling material, and the permeability to the tooth surface and the compatibility with the filling material are improved. Therefore, the dental adhesive composition according to an embodiment of the present invention exhibits high adhesion to the tooth surface and the filling material.

[0015] When the two liquids (or three or more liquids) constituting the adhesive composition according to the present embodiment are mixed, the (A) component in the adhesive layer and the (B) polymer rapidly polymerize, causing a rapid increase in molecular weight. As a result, the film strength is improved, making it less susceptible to the influence of the air blow pressure by air blow or the pressure contact by the filling material, and it becomes easier to form a uniform film, thereby obtaining an adhesive layer having high adhesive strength.

[0016] The above-mentioned (B) radical-polymerizable group-containing liquid polymer 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

[0017] Due to the radically polymerizable group contained in the structural unit (X), the curability of the dental adhesive composition and the adhesiveness to the filling material are further improved. In particular, the rapid polymerization of the polymer (B) having a radically polymerizable group and the polymerizable monomer (A) promotes an increase in molecular weight and rapidly forms a strong film. Therefore, deformation of the film due to air blowing or pressing of the filling material can be suppressed, and an adhesive layer having high adhesive strength can be obtained. Further, since the structural unit (Z) contains an acidic group, the adhesiveness to dentin is further improved. And the structural unit (Y) has a specific alkyl group that 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. As a result, 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.

[0018] 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.) As a result, (B) becomes a liquid 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 also easily dissolves in the filling material, so that an adhesive layer having higher adhesive strength can be formed.

[0019] The above (B) radical polymerizable group-containing liquid polymer may contain 20 to 80 mol% of the structural unit (X) represented by the above general formula (1). This allows for better adhesion to the filler material.

[0020] 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.

[0021] 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. [Effects of the Invention]

[0022] 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. [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 contains (a1) a polymerizable monomer containing an acidic group, (A) a polymerizable monomer, (B) a liquid polymer containing a radical polymerizable group, (C) water, (D) an organic solvent, and (E) a chemical polymerization initiator, and can be configured as a so-called two-component or multi-component type.

[0026] Furthermore, in the adhesive composition according to this embodiment, during the curing process by chemical polymerization induced by the action of (E) a chemical polymerization initiator, (A) polymerizable monomers undergo radical polymerization, and (B) a liquid polymer containing radical polymerizable groups and (a1) an acidic group-containing polymerizable monomer undergo copolymerization. As a result, component (a1) which exhibits adhesion to the tooth surface and component (B) which exhibits adhesion to the filler material are cured together as a single unit, resulting in an adhesive layer with high adhesive strength.

[0027] The adhesive composition according to this embodiment is not a specially constructed filling material, but is widely applicable to general filling materials and can be used as a dental adhesive that does not require light irradiation. Furthermore, the filling material to which the adhesive composition containing the polymer according to this embodiment is applied is not particularly limited as long as it contains a compound that generates radicals, and can be applied to both photopolymerized and chemically polymerized materials.

[0028] 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.

[0029] <Detailed Configuration> [(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.

[0030] (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 during the curing process by chemical polymerization, 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.

[0031] 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.

[0032] (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.

[0033] (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, during curing by chemical polymerization, (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.

[0034] Because it has high stability against water and can slowly dissolve the smear layer on the tooth surface and demineralize teeth, it is preferable that the acidic group is a compound having a carboxyl group, a dihydrogen phosphate monoester group, or a hydrogen phosphate diester group, and most preferably a compound having a dihydrogen phosphate monoester group and / or a hydrogen phosphate diester group.

[0035] 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.

[0036] 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.

[0037] Furthermore, examples of acid monomers having a phosphono group include 3-(meth)acryloyloxypropylphosphonic acid, 6-(meth)acryloylhexylphosphonic acid, and 10-(meth)acryloyloxydecylphosphonic acid.

[0038] 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.

[0039] These acid monomers can be used individually or in combination.

[0040] ·(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.

[0041] (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.

[0042] (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.

[0043] 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. 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.

[0044] (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).

[0045] (a2) The proportion of the polymerizable monomer that does not contain acidic groups is not particularly limited, but 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, more preferably 65 to 95 parts by mass, and particularly preferably 70 to 90 parts by mass, per 100 parts by mass of polymerizable monomer (A).

[0046] [(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 radical polymerizable unsaturated groups. Liquid means having the property of being fluid at room temperature (15-30°C). That is, the (B) polymer according to this embodiment is typically not solid, but has the property of flowing in an amorphous manner. In the dental adhesive composition according to this embodiment, the radical polymerizable groups of polymer (B), which originally have a certain degree of polymerization, polymerize with component (A), resulting in faster curing compared to dental adhesive compositions composed solely of monomers.

[0047] In the dental adhesive composition according to this embodiment, the inclusion of the polymer (B) allows for a certain degree of viscosity in the liquid. Furthermore, after mixing the two components (or three or more components) constituting the adhesive composition, the polymer (B) having polymerizable groups polymerizes with component (A), promoting an increase in molecular weight. As a result, a strong film is quickly formed, and deformation of the film due to air blowing or pressure contact of filling materials can be suppressed. In addition, because polymer (B) has polymerizable groups, it can harden integrally with component (A), and an amount sufficient to ensure sufficient film strength can be incorporated. This makes it easier to form a uniform film and obtain an adhesive layer with stable and high adhesive strength. Moreover, if polymer (B) has structural units (Z) in its structure, polymer (B) itself can adhere to the tooth surface, thus further increasing the adhesive strength of the dental adhesive composition of the present invention to tooth structure.

[0048] Another advantage of polymer (B) is its wide range of solvent options. Polymers such as polylower (meth)acrylates commonly used 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, the (B) radical polymerizable group-containing liquid polymer exhibits good solubility in ethanol and achieves high adhesive strength through uniform dispersion. Thus, the adhesive composition according to this embodiment can use ethanol, which has low biotoxicity, and is suitable for use in treatment.

[0049] (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.

[0050] 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.

[0051] • Structural unit (X) Structural unit (X) is represented by the following general formula (1) and is a structure derived from a (meth)acrylic monomer having a radically polymerizable unsaturated group. Structural unit (X) polymerizes with component (A) by radical polymerization, thereby promoting an increase in the molecular weight of the polymerizable component. This allows for the rapid formation of a strong film, which suppresses deformation of the film due to air blowing or pressure contact of the filling material, resulting in good adhesion between the tooth structure and the filling material. [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.)

[0052] 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.

[0053] 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).

[0054] 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.)

[0055] 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.

[0056] 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.

[0057] 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).

[0058] • Structural unit (Y) The structural unit (Y) is represented by the following general formula (2) and is a structure derived from a (meth)acrylic monomer having an alkyl group, the alkyl group may also contain an ethylene glycol chain. The inclusion of structural unit (Y) improves compatibility with tooth structure and filling material, enhances penetration into the tooth surface and compatibility with the monomer of the filling material, and forms 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.)

[0059] 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.

[0060] 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 a liquid with appropriate fluidity, improving adhesion to the tooth surface and filling material.

[0061] 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.

[0062] • 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.)

[0063] 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.

[0064] 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}.

[0065] 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.

[0066] Specific examples of structural units (Z) having a phosphono group include 3-(meth)acryloyloxypropylphosphonic acid, 6-(meth)acryloylhexylphosphonic acid, and 10-(meth)acryloyloxydecylphosphonic acid.

[0067] (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.

[0068] [(C) 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 500 parts by mass, and more preferably 30 to 300 parts by mass, per 100 parts by mass of (A) polymerizable monomer.

[0069] 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.

[0070] [(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 30 parts by mass, per 100 parts by mass of polymerizable monomer (A).

[0071] [(E) Chemical polymerization initiator] (E) Chemical polymerization initiators have the function of increasing adhesive strength by polymerizing and hardening the (A) polymerizable monomer components that have penetrated the tooth structure, which is the adherend. (E) Examples of chemical polymerization initiators include chemical polymerization initiators that combine oxidizing agents, reducing agents, and transition metal complexes as needed, and known ones can be used. Here, the oxidizing agent and reducing agent of the chemical polymerization initiator (A) immediately initiate a radical polymerization reaction upon contact in the presence of a polymerizable monomer. In other words, the adhesive composition according to this embodiment is a two-component or multi-component adhesive composition that is divided into multiple agents so as to be a combination of components that can be stored stably, and polymerization starts and curing occurs when each agent is mixed at the time of use.

[0072] The proportion of the chemical polymerization initiator to be added is 0.1 to 30 parts by mass per 100 parts by mass of (A) polymerizable monomer, and preferably 1 to 20 parts by mass from the viewpoint of increasing the degree of polymerization.

[0073] (E) The chemical polymerization initiator preferably contains (e1) a borate compound, and more preferably contains, for example, triethanolamine salt of tetraphenylboron, sodium salt of tetraphenylboron, sodium salt of tetrakis(p-fluorophenyl)boron, triethanolamine salt of tetrakis(p-fluorophenyl)boron, sodium salt of tetrakis(3,5-bistrifluoromethyl)phenylboron, triethanolamine salt of tetrakis(3,5-bistrifluoromethyl)phenylboron, phosphonium ion salt of tetrakis(3,5-bistrifluoromethyl)phenylboron, etc. This provides a high curing acceleration function and an adhesive layer with higher adhesive strength. From the viewpoint of obtaining a higher curing acceleration function, the proportion of the borate compound to be blended is more preferably 1 to 20 parts by mass, and more preferably 2 to 15 parts by mass, per 100 parts by mass of polymerizable monomer (A).

[0074] Chemical polymerization initiators that exhibit high polymerization activity in the presence of acid include combinations of oxidizing agents consisting of highly thermally stable organic peroxides such as hydroperoxides, ketone peroxides, peroxyesters, and diacyl peroxides, and reducing agents consisting of borate compounds, amines, sulfinic acid compounds, thiourea compounds, oxime compounds, and transition metal compounds. These reducing agents may function individually or in combination of multiple agents. The oxidizing agent and reducing agent can be used individually or in combination of two or more.

[0075] Furthermore, chemical polymerization initiators combining hydroperoxides and thiourea compounds exhibit high storage stability and high activity in the presence of acid, making them particularly suitable for use as chemical polymerization initiators in dentistry. By selecting specific compounds as thiourea compounds, or by combining them with polymerization accelerators other than thiourea compounds, such as copper compounds, various characteristics can be achieved.

[0076] [Other ingredients] The adhesive composition may contain various additives other than those listed above, as needed. Examples of additives include fillers, polymerization inhibitors, coating strengtheners, photopolymerization initiators, polyvalent metal compounds, and colorants, with the inclusion of fillers and polymerization inhibitors being particularly preferred.

[0077] · 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.

[0078] 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.

[0079] 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.

[0080] 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.

[0081] 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.

[0082] 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.

[0083] Furthermore, the substances listed above may be used individually as fillers, or two or more may be used in combination. [Examples]

[0084] 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.

[0085] <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 DMA: Dodecyl methacrylate TDMA: Tridecyl methacrylate • Monomers of structural units (Z) PM1:2-(phosphonooxy)ethyl methacrylate PA1:2-(phosphonooxy)ethyl acrylate Other compounds used THF: Tetrahydrofuran TEA: Triethylamine DIPE: Diisopropyl ether AIBN: Azovis (isobutyronitrile) [(E) Polymerization initiator] (Reducing agent) EtTU: Ethylenethiourea BzTU:N-benzoylthiourea Ph4B·TEOA: Triethanolamine salt of tetraphenylboron Kalibor: Sodium salt of tetraphenylboron (Oxidizing agent) TGX: t-butylperoxy-3,5,5-trimethylhexanoate Ph4B·TEOA: Triethanolamine salt of tetraphenylboron Cu(OAc)2: Copper(II) acetate monohydrate BMOV: Bis(maltolate)oxovanadium(IV) [Other ingredients] · Filler DM-30: Average primary particle size of 7 nm, dimethyldichlorosilane-treated silica particles (manufactured by Tokuyama Corporation) • Polymerization inhibitors BHT: Dibutylhydroxytoluene Other polymers PMMA: Polymethyl methacrylate (weight-average molecular weight 1,000,000).

[0086] <(B) Radical polymerizable group-containing liquid polymers P1-P7 and reference polymer P8> [(B) Synthesis of radical polymerizable group-containing liquid polymers and reference polymers] (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.

[0087] 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.

[0088] 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]

[0089] 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.

[0090] (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]

[0091] 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 the weight-average molecular weight Mw = 4300.

[0092] (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.

[0093] (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.

[0094] [(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.

[0095] 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.

[0096] [Table 1]

[0097] <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.

[0098] [Preparation of dental adhesive compositions] Adhesive compositions were prepared according to Examples 1-30 and Comparative Examples 1-8.

[0099] In the adhesive composition according to Example 1, 3.0 g of MDP, 3.0 g of BisGMA, 2.0 g of 3G, 2.0 g of HEMA, 0.05 g of P2, 10 g of ethanol, 0.1 g of EtTU, 2.0 g of DM-30, and 0.02 g of BHT were mixed to obtain Component 1. In addition, 15.6 g of ethanol, 1.8 g of water, 0.9 g of Kalibol, 0.3 g of Perocta H, and 0.001 g of BHT were mixed to obtain Component 2.

[0100] In Examples 2-29 and Comparative Examples 1-8, dental adhesive compositions were prepared in the same manner as in Example 1, except that the components and their mixing ratios were changed. The components and mixing ratios of each adhesive composition are shown in Tables 2 and 3 below. In the tables, "↑" means "same as above".

[0101] [Evaluation of adhesive compositions] Next, the tensile adhesive strength of the obtained adhesive compositions was evaluated.

[0102] The adhesive strength to tooth structure was measured as follows. Bovine incisors extracted within 24 hours of slaughter were polished with waterproof abrasive paper P600 under water, and the enamel surface was ground down to be parallel and flat to the lip surface to prepare the substrate. Next, double-sided tape with a 3mm diameter hole was attached to the polished surface of the adherend. Subsequently, the first and second components of the dental adhesive composition prepared in each example and comparative example were mixed in a 1:1 volume ratio. This mixture was then 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 coated with the dental adhesive composition so that the hole in the paraffin wax and the hole in the double-sided tape were concentric. A simulated cavity was then created by filling this simulated cavity with dental composite resin (Esterite Σ Quick, manufactured by Tokuyama Dental Co., Ltd.) and lightly pressing it with a polyester film. Finally, photocuring was performed by irradiating it with light for 10 seconds using a visible light curing unit (Elliper, manufactured by 3M ESPE). Subsequently, a pre-polished SUS304 round bar (8 mm in diameter, 18 mm in height) was bonded with resin cement (Estesem II, manufactured by Tokuyama Dental Co., Ltd.) to prepare 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. Adhesion strength (MPa) = Maximum load (N) / Adhesion area (mm²) 2 ). Measurements were performed 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.

[0103] Examples 1 to 29 shown in Tables 2 and 3 utilize dental adhesive compositions formulated to satisfy the characteristics of the present invention.

[0104] The adhesive compositions shown in Comparative Examples 1 to 8 in Table 4 are examples in which polymers are used in which each component does not satisfy the configuration shown in the present invention. When component (B) is not present, or when the content of component (B) is less than 0.1 parts by mass, or when a polymer without polymerizable groups is used, it is thought that the adhesive strength was low because the strength of the adhesive layer after air blowing was insufficient (Comparative Examples 1, 2, and 4). When the content of component (B) exceeds 50 parts by mass, it is thought that the adhesive strength was low because the concentration of component (A) decreases (Comparative Example 3). When a polymer with polymerizable groups but a solid state is used, it is thought that the adhesive composition did not adhere well to the tooth surface, resulting in low adhesive strength (Comparative Example 5). When component (a1) is not present, it is thought that the amount of adhesive component relative to the tooth structure was insufficient, resulting in low adhesive strength (Comparative Example 6). When component (E) is not present, it is thought that the adhesive strength was low because the curing of the adhesive layer was insufficient (Comparative Example 7). When component (D) is not present, it is thought that the adhesive strength was low because the demineralization of the tooth surface was insufficient (Comparative Example 8).

[0105] [Table 2] [Table 3] [Table 4]

Claims

1. 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, 50 to 500 parts by mass of (C) organic solvent, 1 to 50 parts by mass of (D) water, 0.1 to 30 parts by mass of (E) chemical polymerization initiator, It contains, The (B) radical polymerizable group-containing liquid polymer comprises 5 to 80 mol% of structural units (X) represented by the following general formula (1), 15 to 90 mol% of structural units (Y) represented by the following general formula (2), and 0 to 50 mol% of structural units (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.

2. A dental adhesive composition according to claim 1, 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.

3. A dental adhesive composition according to claim 1, The (E) chemical polymerization initiator comprises (e1) a borate compound. Dental adhesive composition.

4. A dental adhesive composition according to claim 1, 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.

5. A dental adhesive composition according to claim 1, 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.

6. A dental adhesive composition according to claim 1, 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.

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