Polymer and dental adhesive composition using same

Abstract

To provide a polymer which does not need to be cured at a stage before a filling material is charged, is easily cured, and can be applied to various filling materials, and to provide a dental adhesive composition containing the polymer.SOLUTION: The polymer includes: 5 to 80 mol% of a structural unit (X) that is derived from a (meth)acrylic monomer having a radically polymerizable unsaturated group; 15 to 90 mol% of a structural unit (Y) that is derived from a (meth)acrylic monomer having an alkyl group; and 5 to 50 mol% of a structural unit (Z) that is derived from a (meth)acrylic monomer containing an acidic group, each of which is represented by a specific general formula. The structural unit (X) improves the adhesiveness to the filling material; the structural unit (Z) improves the adhesiveness to a tooth substance; and the structural unit (Y) improves the compatibility with the tooth substance and the filling material, and improves the permeability to a tooth surface and the compatibility with the filling material. Thereby, the dental adhesive composition including the polymer according to one embodiment of the present invention exhibits high adhesiveness to the tooth surface and the filling material.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a polymer having adhesive properties and a dental adhesive composition. [Background technology]

[0002] Hardening filling materials called composite resins are used to repair teeth damaged by caries and other conditions. These filling materials have almost no adhesive properties to the tooth structure that makes up the tooth. For this reason, filling materials are usually bonded to the tooth structure via an adhesive. Conventional adhesives must be pre-cured to achieve high adhesive strength.

[0003] A photocurable adhesive that can be cured by light irradiation is known as an adhesive that can be used to bond filling materials (see, for example, Patent Document 1). The photocurable adhesive must be cured by light irradiation in the oral cavity before filling with the filling material. Light irradiation for several seconds to several tens of seconds is required for the photocurable adhesive to harden.

[0004] For this reason, light-curing adhesives place a heavy burden on patients due to the prolonged treatment time and heat generated by 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, blood, etc. Therefore, there is a demand for adhesives that do not require light irradiation before filling with filling material.

[0005] Patent Document 2 discloses an adhesive that does not require curing by light irradiation. This adhesive is a two-component type, meaning that it is configured to undergo chemical polymerization curing by mixing a first component and a second component. However, with this adhesive, it takes time to mix the first and second components during treatment and it takes time to cure them.

[0006] Patent Document 3 also discloses a one-component dental adhesive that does not require light irradiation. In this adhesive, after filling with a filling material, light is irradiated during hardening of the filling material to promote photopolymerization curing, and aromatic amines are supplied from the filling material to promote chemical polymerization curing, eliminating the need for additional time for curing the adhesive. However, this adhesive cannot be used with filling materials other than those containing aromatic amines. [Prior art documents] [Patent documents]

[0007] [Patent Document 1] Japanese Patent Application Laid-Open No. 2009-137960 [Patent Document 2] Japanese Patent Application Publication No. 2018-027913 [Patent Document 3] Japanese Patent Publication No. 2020-138911 Summary of the Invention [Problem to be solved by the invention]

[0008] Therefore, in order to realize a quick dental treatment that places less strain on the patient, there is a need for an adhesive that can be easily cured without the need for light irradiation before filling with a filling material, and that can be used for general purposes. However, at present, the only adhesives known that have such a configuration are those that are not compatible with general-purpose filling materials.

[0009] In view of the above circumstances, an object of the present invention is to provide a polymer that hardens easily without requiring hardening before filling with a filling material, and that is applicable to various filling materials, and a dental adhesive composition containing the same. [Means for solving the problem]

[0010] In order to achieve the above object, a polymer according to one embodiment of the present invention 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 5 to 50 mol % of structural units (Z) represented by the following general formula (3): [ka] (In general formula (1), R 1 and R 2 represents a hydrogen atom or a methyl group, and n represents an integer of 1 to 15. [ka] (In general formula (2), R 3 represents a hydrogen atom or a methyl group, and R 4 represents a group having a total of 1 to 15 carbon atoms and represented by the following general formula (2-1). [ka] (In the above formula, p represents an integer of 0 to 5, and R ' represents an alkyl group. [ka] (In general formula (3), R 5 represents a hydrogen atom or a methyl group, L represents a dihydrogen phosphate monoester group {-O-P(=O)(OH)} or a phosphono group {-P(=O)(OH)}, and m represents an integer of 1 to 15.

[0011] The polymer according to one embodiment of the present invention has a radically polymerizable unsaturated group and is used in an adhesive that undergoes radical polymerization. When the polymer according to one embodiment of the present invention is used as a dental adhesive composition, the structural unit (X) improves adhesion to filling materials, and the structural unit (Z) improves adhesion to tooth structure. Furthermore, the structural unit (Y) improves compatibility with tooth structure and filling materials, improving penetration into tooth surfaces and compatibility with filling materials. This allows dental adhesive compositions containing the polymer according to one embodiment of the present invention to exhibit high adhesion to tooth surfaces and filling materials.

[0012] When a dental adhesive composition containing a polymer according to one embodiment of the present invention is cured, polymerization is allowed to proceed on a polymer that originally has a certain degree of polymerization, so that the dental adhesive composition has fewer unbonded sites and can be easily cured with fewer radicals than a dental adhesive composition composed of a monomer component. As a result, the polymer according to one embodiment of the present invention can provide a dental adhesive composition that can be cured using radicals generated when curing a filling material. Therefore, it is possible to realize an adhesive that can be easily cured without the need for curing before filling the filling material, and that can be applied to various filling materials regardless of the composition of the filling material.

[0013] In the above general formula (2), R 3 If is a hydrogen atom, R 4 is a group having a total of 1 to 15 carbon atoms, and R 3 If is a methyl group, R 4 may represent a group having a total of 4 to 15 carbon atoms. This makes it easy to obtain a polymer with flowability, which makes it easy for a dental adhesive composition containing the polymer according to one embodiment of the present invention to adhere to the tooth surface when applied to the tooth surface as a dental adhesive, and also makes it easy for the composition to be compatible with the filling material, thereby making it possible to form an adhesive layer with higher adhesive strength.

[0014] The polymer may be a liquid adhesive polymer. This makes it possible to form an adhesive layer with higher adhesive strength.

[0015] The polymer may have a weight average molecular weight of 1,000 or more and 50,000 or less as measured by gel permeation chromatography (GPC) using styrene as a standard. This provides an appropriate viscosity, which improves adhesion to the tooth surface and filling material, resulting in higher adhesive strength.

[0016] In the general formula (3), L may be a dihydrogen phosphate monoester group {—OP(═O)(OH) 2}. This improves adhesion to the tooth surface, and when used as a dental adhesive, an adhesive layer with higher adhesive strength can be formed.

[0017] The structural unit (Y) represented by the general formula (2) may be a structure derived from a monomer selected from methyl acrylate, ethyl acrylate, propyl acrylate, butyl (meth)acrylate, pentyl (meth)acrylate, (meth)hexyl, 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. This allows the structural unit (Y) to further improve its penetration into tooth surfaces and compatibility with filling materials, thereby providing good adhesion to tooth surfaces and filling materials, and therefore when the polymer is used in a dental adhesive, an adhesive layer with higher adhesive strength can be formed.

[0018] A dental adhesive composition according to one embodiment of the present invention contains the above polymer, a polymerizable monomer, a solvent, and water. As described above, this dental adhesive composition provides high adhesion to tooth surfaces and filling materials, and can form an adhesive layer with higher adhesive strength. [Effects of the Invention]

[0019] According to the present invention, it is possible to provide a polymer that is easily cured without the need for light irradiation at a stage prior to filling with a filling material, and that is applicable to a variety of filling materials, and a dental adhesive composition containing the same. [Brief explanation of the drawings]

[0020] [Figure 1] 1 is a partial cross-sectional view schematically illustrating a process of adhering a filling material to a tooth using an adhesive composition according to one embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0021] Hereinafter, embodiments of the present invention will be described in detail. In the following description, the numerical range "x to y" includes x and y, that is, "x to y" means "x or more and y or less." In addition, 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."

[0022] <Overall structure> A polymer according to one embodiment of the present invention can be used to repair teeth damaged by caries, etc. More specifically, a polymer according to one embodiment of the present invention can be used to adhere a dental filling material (hereinafter simply referred to as filling material) contained in a dental adhesive composition (hereinafter simply referred to as adhesive composition) to be filled in a damaged part of a tooth, to the tooth substance that constitutes the surface of the damaged part.

[0023] The polymer according to this embodiment contains structural units (X) to (Z) and has adhesive properties to tooth structures and filling materials.

[0024] When the adhesive composition containing the polymer according to this embodiment is applied to a tooth, the concave damaged portion of the tooth is filled with a filling material without curing the adhesive composition. Fig. 1 is a partial cross-sectional view schematically showing the state in which the filling material has been filled into the damaged portion of the tooth via the adhesive composition. In the state shown in Fig. 1, the uncured adhesive composition and the uncured filling material are in direct contact with each other.

[0025] When light irradiation is performed to harden the filling material from the state shown in FIG. 1, radicals are generated by the action of the photopolymerization initiator in the filling material, and photopolymerization hardening proceeds.

[0026] In general 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 sufficiently polymerize and cure the various monomers. In such adhesives, if polymerization is promoted using irradiation light that has passed through the filling material, residual monomers remain in the interior where the light cannot easily reach, resulting in a decrease in adhesive strength. In contrast, when the above polymer is used in an adhesive composition, since the adhesive component is polymerized in advance, polymerization can proceed sufficiently even with a small amount of radicals, and the adhesive composition can be cured.

[0027] The adhesive composition containing the polymer according to this embodiment utilizes radicals generated from a photopolymerization initiator that is always contained in photocurable filler materials, and is therefore widely applicable to general photocurable filler materials, rather than filler materials with special configurations. Furthermore, the filler 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 it is also applicable to chemical polymerization types.

[0028] Therefore, by using the polymer according to this embodiment, the adhesive composition can be cured quickly and sufficiently, thereby obtaining an adhesive layer with high adhesive strength while minimizing the burden on the patient.

[0029] <Detailed configuration> [polymer] (Structural unit (X)) The 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. The structural unit (X) bonds to the filling material through radical polymerization, improving adhesion to the filling and restorative material. [ka] (In general formula (1), R 1 and R 2 represents a hydrogen atom or a methyl group, and n represents an integer of 1 to 15.

[0030] The structural unit (X) can be obtained by the following synthesis methods I and II. Synthesis method I is preferred in order to reliably obtain the structural unit (X).

[0031] 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 eliminate E, thereby obtaining the 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 represents a hydrogen atom or a methyl group, and p and q represent integers of 1 to 15.

[0032] As the anionic leaving group, a halogen atom, an alkyl or arylsulfonyloxy group, etc. are preferred, with a bromine atom, a chlorine atom, and a p-toluenesulfonyloxy group being particularly preferred. Specific examples thereof include, in terms of ease of availability of synthetic raw materials, 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.

[0033] The base that induces the elimination reaction may be either an inorganic base or an organic base. Preferred inorganic compound bases include sodium hydroxide, potassium hydroxide, sodium carbonate, sodium hydrogencarbonate, potassium carbonate, potassium hydrogencarbonate, etc., and preferred organic compound bases include metal alkoxides such as sodium methoxide, sodium ethoxide, and potassium t-butoxide, and organic amine compounds such as triethylamine, pyridine, and diisopropylethylamine.

[0034] 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)acrylic acid chloride, (meth)acrylic acid anhydride, or the like to obtain structural unit (X).

[0035] (Structural unit (Y)) The structural unit (Y) is represented by the following general formula (2) and is derived from a (meth)acrylic monomer having an alkyl group, which may contain an ethylene glycol chain. The inclusion of the structural unit (Y) improves compatibility with tooth structure and filling materials, improves penetration into the tooth surface, and improves compatibility with the filling material monomer, forming an adhesive layer with good adhesion to the tooth surface and filling materials. [ka] (In general formula (2), R 3 represents a hydrogen atom or a methyl group, and R 4represents a group having a total of 1 to 15 carbon atoms and represented by the following general formula (2-1). [ka] (In the above formula, p represents an integer of 0 to 5, and R′ represents an alkyl group.)

[0036] From the viewpoint of further improving the penetration into the tooth surface and the compatibility with the monomer of the filling material, R 3 If is a hydrogen atom, R 4 is a group having a total of 1 to 15 carbon atoms, and R 3 If is a methyl group, R 4 preferably represents a group having a total carbon number of 4 to 15. This allows the polymer according to this embodiment to have good fluidity, improving adhesion to tooth surfaces and filling materials.

[0037] In particular, from the viewpoint of making the polymer liquid, it is preferred 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.

[0038] (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 the structural unit (Z) has a demineralizing effect on tooth tissue and also acts as an adhesive component to tooth tissue, thereby improving the adhesion of the filling and restorative material to tooth tissue. [ka] (In general formula (3), R 5represents a hydrogen atom or a methyl group, L represents a dihydrogen phosphate monoester group {-O-P(=O)(OH)} or a phosphono group {-P(=O)(OH)}, and m represents an integer of 1 to 15.

[0039] L is preferably a dihydrogen phosphate monoester group {—OP(═O)(OH) 2}, since it has high stability in water and can slowly dissolve the smear layer on the tooth surface and demineralize the teeth.

[0040] Specific examples of the structural unit (Z) having a dihydrogen phosphate monoester group include 2-(phosphonooxy)ethyl methacrylate, 6-(phosphonooxy)hexyl(meth)acrylate, and 10-(phosphonooxy)decyl(meth)acrylate.

[0041] Specific examples of the structural unit (Z) having a phosphono group include 3-(meth)acryloyloxypropylphosphonic acid, 6-(meth)acryloylhexylphosphonic acid, and 10-(meth)acryloyloxydecylphosphonic acid.

[0042] (Ratio of each structural unit (X), (Y), (Z)) A polymer according to one embodiment of the present invention comprises 5 to 80 mol % of structural units (X), 15 to 90 mol % of structural units (Y), and 5 to 50 mol % of structural units (Z), and more preferably 10 to 70 mol % of (X), 20 to 80 mol % of structural units (Y), and 10 to 40 mol % of structural units (Z). This allows the above-mentioned functions of each structural unit to be exerted without deterioration, and an adhesive layer having high adhesive strength can be obtained due to the synergistic effect of the structural units (X) to (Z).

[0043] (Polymer properties) The polymer of one embodiment of the present invention is typically a liquid adhesive polymer. Liquid refers to a state in which the polymer has fluidity at room temperature (15 to 30°C). That is, the polymer of this embodiment is typically not solid but has the property of flowing in an amorphous form. This further improves the penetration into the tooth surface and the compatibility with the monomer of the filling material, resulting in better adhesion to the tooth surface and the filling material.

[0044] (molecular weight of polymer) The weight-average molecular weight is measured by gel permeation chromatography (GPC) using styrene as a standard. A weight-average molecular weight of 1,000 to 50,000 provides a moderate viscosity, ensuring that the coating will not run when applied to the tooth surface as a dental adhesive, ensuring the desired thickness. Even when air-blowing is used to remove the solvent after application, the coating remains uniform. This allows for the formation of an adhesive layer with high adhesive strength. From the viewpoint of obtaining even higher adhesive strength, the weight average molecular weight of the polymer is more preferably more than 2,000, and even more preferably less than 20,000.

[0045] [Dental adhesive composition] A dental adhesive composition according to one embodiment of the present invention contains the above-mentioned polymer, a polymerizable monomer, a solvent, and water, and is configured as a so-called one-component type. The dental adhesive composition according to one embodiment of the present invention does not contain a photopolymerization initiator, since it is configured to utilize the action of the photopolymerization initiator contained in the filling material. Therefore, the dental adhesive composition according to one embodiment of the present invention can be used as a one-component dental adhesive that does not require light irradiation.

[0046] (Polymerizable monomer) Any known polymerizable monomer can be used without limitation as the polymerizable monomer, but from the viewpoint of obtaining even higher adhesion and adhesion durability to tooth structure, it is preferable to further include an acidic group-free polymerizable monomer that does not contain an acidic group.

[0047] The acidic group-free polymerizable monomer may be any known compound without particular limitation, as long as it does not contain an acidic group and contains one or more polymerizable unsaturated groups in one molecule. From the viewpoint of adhesiveness, the polymerizable unsaturated group is preferably an acryloyl group, a methacryloyl group, an acrylamide group, a methacrylamide group, or the like.

[0048] Among the acidic group-free polymerizable monomers, polyfunctional polymerizable monomers are preferably used from the viewpoint of adhesion to tooth structure and adhesion durability. Specific examples of polyfunctional polymerizable monomers that are preferably used include 2,2'-bis{4-[2-hydroxy-3-(meth)acryloyloxypropoxy]phenyl}propane, triethylene glycol methacrylate, 2,2-bis[(4-(meth)acryloyloxypolyethoxyphenyl)propane], 1,6-bis(methacrylethyloxycarbonylamino)-2,2,4-trimethylhexane, 1,6-bis(methacrylethyloxycarbonylamino)-2,4,4-trimethylhexane, and trimethylolpropane trimethacrylate.

[0049] The polymerizable monomer having no acidic group may be used alone or in combination of two or more thereof. The polymerizable monomer having no acidic group may be used alone or in combination of two or more thereof.

[0050] The blending ratio of the non-acidic group-containing polymerizable monomer is not particularly limited, but from the viewpoint of further ensuring the adhesiveness-improving effect of the polymer, the blending ratio of the non-acidic group-containing polymerizable monomer is preferably 10 parts by mass to 10,000 parts by mass, and more preferably 20 parts by mass to 5,000 parts by mass, per 100 parts by mass of the polymer.

[0051] (water) From the viewpoints of storage stability, biocompatibility, and adhesiveness, it is preferable that the water is substantially free of harmful impurities, and examples that can be used include deionized water, distilled water, etc. The blending ratio of water is 10 parts by mass to 1000 parts by mass, preferably 20 parts by mass to 500 parts by mass, and particularly preferably 50 parts by mass to 200 parts by mass, per 100 parts by mass of the polymer.

[0052] (organic solvent) Any known organic solvent can be used without limitation as the organic solvent, but it is usually preferable to use a highly volatile organic solvent with a boiling point of less than 100° C. The blending ratio of the organic solvent is 10 parts by mass to 3000 parts by mass, and preferably 30 parts by mass to 1000 parts by mass, per 100 parts by mass of the polymer.

[0053] Specific examples of organic solvents include alcohols such as ethanol, isopropyl alcohol, and butanol; and ketones such as acetone and methyl ethyl ketone. Among these, acetone, ethanol, and isopropyl alcohol are particularly preferred for reasons of biological safety, solubility, and storage stability. As the organic solvent, one or a combination of two or more organic solvents can be used.

[0054] (Other ingredients) The adhesive composition may contain various additives other than the above-mentioned components, as needed, such as polyvalent metal compounds, fillers, colorants, and polymerization inhibitors such as hydroquinone, hydroquinone monomethyl ether, and dibutylhydroxytoluene.

[0055] Since the polymer of the present invention has a novel structure, it may be useful in a wide range of applications other than adhesives. In other words, the applications of the polymer of the present invention are not limited to adhesives. [Example]

[0056] The present invention will be described below with reference to examples, but the present invention is not limited to the following examples in any way.

[0057] <Substance abbreviation> First, the abbreviations of the substances used in the examples and comparative examples will be explained below. [Structural unit (X) monomer] 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 [Structural unit (Y) monomer] MA: Methyl acrylate (Tokyo Chemical Industry Co., Ltd.) DGMA: Diethylene glycol monomethyl ether methacrylate (Tokyo Chemical Industry Co., Ltd.) BMA: Butyl methacrylate (Tokyo Chemical Industry Co., Ltd.) MMA: Methyl methacrylate (Tokyo Chemical Industry Co., Ltd.) DMA: Dodecyl methacrylate (Tokyo Chemical Industry Co., Ltd.) TDMA: Tridecyl methacrylate (Tokyo Chemical Industry Co., Ltd.) [Structural unit (Z) monomer] PM1: 2-(phosphonooxy)ethyl methacrylate (P-1M (Kyoeisha Chemical Co., Ltd.) purified with water / dichloromethane) PA1: 2-(phosphonooxy)ethyl acrylate (P-1A (Kyoeisha Chemical Co., Ltd.) purified with water / dichloromethane) MDP: 10-(phosphonooxy)decyl methacrylate (manufactured by Shin-Nakamura Chemical Co., Ltd.) [Other monomers] Bis-GMA: 2,2'-bis[4-(3-methacryloyloxy)-2-hydroxypropoxyphenyl]propane (manufactured by Shin-Nakamura Chemical Co., Ltd.) 3G: Triethylene glycol dimethacrylate (manufactured by Shin-Nakamura Chemical Co., Ltd.) HEMA: 2-hydroxyethyl methacrylate (Shin-Nakamura Chemical Co., Ltd.) AA: Acrylic acid (Tokyo Chemical Industry Co., Ltd.) ODMA: Octadecyl methacrylate (Tokyo Chemical Industry Co., Ltd.) [Other compounds] THF: Tetrahydrofuran (Fujifilm Wako Pure Chemical Industries, Ltd.) TEA: Triethylamine (Fujifilm Wako Pure Chemical Industries, Ltd.) DIPE: Diisopropyl ether (Fujifilm Wako Pure Chemical Industries, Ltd.) AIBN: Azobis(isobutyronitrile) (Fujifilm Wako Pure Chemical Industries, Ltd.)

[0058] <Examples 1 to 16 and Comparative Examples 1 to 5> [Polymer synthesis] Polymers [1] to

[21] according to Examples 1 to 16 and Comparative Examples 1 to 5 were synthesized by the following methods. The components and blending ratios of each polymer are shown in Table 1 below.

[0059] First, the monomer of the structural unit (X) was synthesized. 1.7 g (15 mmol) of 3-bromoisobutyric acid (Tokyo Chemical Industry Co., Ltd.) was weighed into a 200 mL round-bottom flask. 100 mL of THF was added, followed by 3.5 g (18 mmol) of 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide (Tokyo Chemical Industry Co., Ltd.), 0.1 g (1 mmol) of 4-dimethylaminopyridine (Fujifilm Wako Pure Chemical Industries, Ltd.), and 1.3 g (10 mmol) of 2-hydroxyethyl acrylate (Shin-Nakamura Chemical Co., Ltd.). After 6 hours, the solvent was removed using an evaporator, and 100 mL of ethyl acetate was added. The ethyl acetate layer was washed three times with 100 mL of water. Magnesium sulfate was added to the ethyl acetate layer to dry it, and the ethyl acetate was removed under reduced pressure using an evaporator. The resulting compound was dried at 80 °C for 1 hour while bubbling oxygen, yielding 2.2 g of BrMPMA in a 75% yield. When synthesizing BrMPA, 2-hydroxyethyl acrylate (manufactured by Tokyo Chemical Industry Co., Ltd.) was used instead of 2-hydroxyethyl methacrylate, and when synthesizing BrPMA, 3-bromobutyric acid (manufactured by Tokyo Chemical Industry Co., Ltd.) was used.

[0060] Next, a polymer was synthesized by the following method. (1) Polymer [1] according to Example 1 was synthesized by synthesis method (i). First, the polymerizable group precursor polymer [1] was synthesized as shown in the following reaction scheme. 133 mg (0.5 mmol) of BrMPA, 98 mg (0.5 mmol) of PA1, and 164 mg (1 mmol) of AIBN were weighed into a 100 mL round-bottom flask. After nitrogen substitution, 20 mL of a THF / water (8 / 2) mixed solvent was added, followed by 806 μL (9 mmol) of MA. The mixture was heated and stirred at 65°C in an oil bath for 24 hours. After confirming the disappearance of the monomer using HPLC, the THF was removed under reduced pressure using an evaporator. The resulting crude product was reprecipitated in 20 mL of a DIPE / THF (9 / 1) mixed solvent in an ethanol / dry ice bath and then vacuum-dried to obtain the polymerizable group precursor polymer [1]. [ka]

[0061] Next, we synthesized the polymer [1]. The polymerizable group precursor polymer [1] 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 washed. The dichloromethane layer was washed twice more with 20 mL of 1N hydrochloric acid. The dichloromethane layer was dried over magnesium sulfate, and the dichloromethane was removed under reduced pressure using an evaporator. The polymer was then dried in vacuo, yielding 790 mg (82% yield) of polymer [1]. 1 H-NMR measurement revealed that the composition ratio of structural unit (X) (mol%):structural unit (Y) (mol%):structural unit (Z) (mol%) = 5:90:5 (= x:y:z), and GPC measurement revealed that the weight average molecular weight Mw = 1100.

[0062] (2) Polymer [2] according to Example 2 was synthesized by synthesis method (ii). First, the polymerizable group precursor polymer [2] was synthesized as shown in the following reaction scheme. AIBN (164 mg, 1 mmol) was weighed into a 100 mL round-bottom flask. After nitrogen substitution, 15 mL of a THF / water (8 / 2) mixed solvent was added, followed by 717 μL (8 mmol) of MA. The reaction system was then heated to 65 °C using an oil bath. A solution of PM1 (210 mg, 1 mmol) and BrMPMA (278 mg, 1 mmol) in 5 mL of a THF / water (8 / 2) mixed solvent was added dropwise over 3 hours using a syringe pump. After the addition, the reaction was continued for an additional 21 hours at 65 °C. The disappearance of the monomer was confirmed by HPLC, and the THF was removed under reduced pressure using an evaporator. The resulting crude product was reprecipitated in an ethanol / dry ice bath using 20 mL of diisopropyl ether / THF (8 / 2) and then dried under vacuum to obtain the polymerizable group precursor polymer [2]. [ka]

[0063] Next, we synthesized the polymer [2]. The polymerizable group precursor polymer [2] was converted to polymer [2] in the same manner as in the synthesis method (i), and 942 mg (yield 86%) of polymer [2] was obtained. 1 H-NMR measurement revealed that the composition ratio of structural unit (X) (mol%):structural unit (Y) (mol%):structural unit (Z) (mol%) was 9:81:10 (=x:y:z), and GPC measurement revealed that the weight average molecular weight Mw was 3,300.

[0064] (3) Polymers [3] to

[11] and

[14] to

[20] according to Examples 3 to 11, 14 to 16 and Comparative Examples 1 to 4 were synthesized. Polymers [3] to

[11] and

[14] to

[20] were synthesized using a method similar to synthesis method (i) or (ii). Due to the difference in copolymerizability between methacrylate monomers and acrylate monomers, synthesis method (i) was used when only methacrylate monomers or acrylate monomers were used, and synthesis method (ii) was used when methacrylate monomers and acrylate monomers were used in combination.

[0065] (4) As shown in the following reaction scheme, polymers

[12] ,

[13] , and

[21] according to Examples 12 and 13 and Comparative Example 5 were synthesized in the same manner as in Synthesis Method (i), except that 82 mg (0.5 mmol) of AIBN was used. [ka]

[0066] [Polymer analysis] The properties, weight-average molecular weight, and yield of the obtained polymer are shown in Table 1. Since the polymer of this embodiment is produced by converting a polymerizable group precursor into a polymerizable group, there are no protection or deprotection steps, and the number of steps is small. Therefore, there was little loss due to purification, and the yield was high in both cases. The weight average molecular weight was measured by the following method.

[0067] 1H-NMR measurement: JNM-ECAII (400 MHz) manufactured by JEOL Ltd. was used as the measurement device. Deuterated chloroform was used as the measurement solvent, and the measurement sample was diluted 100 times before measurement. GPC measurement: Advanced Polymer Chromatography manufactured by Nihon Waters was used as the measuring device. The columns used were ACQUITY APCTMXT45 (1.7 μm) and ACQUITY APCTMXT125 (2.5 μm), and the column temperature was set to 40°C. THF was used as the developing solvent, and the flow rate was set to 0.5 ml / min. A photodiode array detector at 210 nm was used as the detector. THF was used as the measurement solvent, and the measurement sample was diluted 100-fold before measurement.

[0068] [Table 1]

[0069] <Examples 17 to 32 and Comparative Examples 6 to 11> Adhesive compositions of Examples 17 to 32 and Comparative Examples 6 to 12 were prepared and evaluated for adhesive strength.

[0070] [Synthesis of dental adhesive composition] Adhesive compositions according to Examples 17 to 32 and Comparative Examples 6 to 11 were prepared according to the following formulations, where the numbers in parentheses indicate parts by weight. Composition: Polymer (10) / Bis-GMA (6) / 3G (4) / Acetone (60) / Water (20) Bis-GMA and 3G were used as polymerizable monomers.

[0071] A dental adhesive composition according to Comparative Example 12 was prepared according to the following formulation. No polymer was used in Comparative Example 12. The figures in parentheses indicate parts by weight. Composition: MDP (4) / HEMA (6) / Bis-GMA (6) / 3G (4) / acetone (60) / water (20) As polymerizable monomers, MDP, HEMA, Bis-GMA and 3G were used.

[0072] [Evaluation of adhesive composition] Next, the adhesive composition containing the obtained polymer was evaluated for "tensile adhesive strength."

[0073] The adhesive strength to tooth substrate was measured as follows. Bovine anterior teeth extracted within 24 hours after slaughter were polished with waterproof abrasive paper P600 under running water, and the dentin or enamel surface was scraped off to make it parallel and flat to the labial surface to prepare the substrate. Next, a double-sided tape with a hole of 3 mm diameter was attached to the polished surface of each of these two types of adherends. Subsequently, the dental adhesive composition prepared in each Example and Comparative Example was applied to the adhesive surface of the polished surface exposed through the hole in the double-sided tape, and dried by air blowing for 5 seconds. A 0.5 mm thick paraffin wax sheet with an 8 mm diameter hole was attached to the adhesive surface of the dental adhesive composition, with the hole in the paraffin wax and the hole in the double-sided tape aligned concentrically to create a simulated cavity. This simulated cavity was filled with dental composite resin (Estelite Universal Flow, manufactured by Tokuyama Dental Co., Ltd.) and gently pressed with polyester film. The composite resin was then photocured using a visible light irradiator (Elipar, manufactured by 3M ESPE) for 10 seconds. A pre-polished SUS304 round bar (8 mm diameter, 18 mm height) was then bonded with resin cement (Estecem II, manufactured by Tokuyama Dental Co., Ltd.) to prepare a specimen for evaluation. The composite resin used was a photopolymerizable composition containing camphorquinone and an amine compound. After immersing this test sample in water at 37°C 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 / mm until the test sample broke, and the adhesive strength was calculated from the maximum load using the following formula. Adhesive strength (MPa) = maximum load (N) / adhesion area (mm) 2 ).

[0074] In the adhesive compositions according to Examples 17 to 32, good tensile adhesive strength was obtained in all of the examples.

[0075] The adhesive compositions according to Comparative Examples 6 to 11 are examples in which polymers whose components do not satisfy the constitutional requirements of the present invention were used. Comparative Example 6 is an example in which the structural unit (Z) was not present, and showed low adhesive strength. Comparative Example 7 is an example in which the structural unit (X) was not present, and showed low adhesive strength. Comparative Examples 8 to 10 are examples in which the R 4 is an ethanol group (CH2CH2OH), or R 4 The total number of carbon atoms is 0, 18 (i.e., R 4 H, C 18 H 35 Comparative Example 11 is an example in which the polymer of the present invention was not used and showed low adhesive strength.

[0076]

Table 2

Claims

1. The copolymer 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 5 to 50 mol % of structural units (Z) represented by the following general formula (3): polymer. 【Chemical 1】 (In general formula (1), R １ and R ２ represents a hydrogen atom or a methyl group, and n represents an integer of 1 to 15. 【Chemistry 2】 (In general formula (2), R ３ represents a hydrogen atom or a methyl group, R 4 represents a group having a total of 1 to 15 carbon atoms and represented by the following general formula (2-1): 【Chemistry 3】 (In the above formula, p represents an integer of 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 represents a dihydrogen phosphate monoester group {—O—P(═O)(OH) ２ } or a phosphono group {—P(═O)(OH) ２ }, and m represents an integer of 1 to 15.

2. 10. The polymer of claim 1, In general formula (2), R ３ When is a hydrogen atom, R 4 is a group having a total of 1 to 15 carbon atoms, and R ３ When is a methyl group, R 4 represents a group having a total of 4 to 15 carbon atoms; polymer.

3. 3. The polymer of claim 1 or 2, The polymer is a liquid adhesive polymer. polymer.

4. 4. The polymer of claim 1, The weight average molecular weight of the polymer measured by gel permeation chromatography (GPC) using styrene as a standard is 1,000 or more and 50,000 or less. polymer.

5. 5. The polymer of claim 1, In the general formula (3), L is a dihydrogen phosphate monoester group {—O—P(═O)(OH) ２ } polymer.

6. 6. The polymer of claim 1, The structural unit represented by the 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. polymer.

7. A dental adhesive composition comprising the polymer according to any one of claims 1 to 6, a polymerizable monomer having an acryloyl group, a methacryloyl group, an acrylamide group or a methacrylamide group, a solvent and water.

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