JP5975781B2 - Dental curable composition and method for producing the same - Google Patents

Description

  The present invention relates to a dental curable composition, specifically a dental curable composition containing a dendritic polymer and suitable as a dental filling restorative material, and a method for producing the same.

  For restoration of a tooth damaged by caries, a filling restoration material generally called a composite resin is widely used from the viewpoint of aesthetics. The composite resin is composed of a curable composition containing a polymerizable monomer (monomer), a filler (filler), and a polymerization initiator as main components, and additionally containing pigments and additives as necessary. Here, as the polymerizable monomer, a radical polymerizable radical polymerizable monomer is usually used. For this reason, in the curing, that is, in the polymerization reaction of the radical polymerizable monomer, it is inevitable that polymerization shrinkage occurs.

  Therefore, when the cavity of a tooth that needs to be repaired is filled with a filling restorative material and then cured by radical polymerization, a gap is easily formed between the cured product and the inner wall of the cavity. If such a gap occurs, plaque tends to accumulate in the gap, and secondary caries is likely to occur. Moreover, it becomes easy for the hardened | cured material to drop out from the cavity. Therefore, it is preferable that the polymerization shrinkage of the filling / restoring material during curing is as small as possible.

  As one of the methods to suppress polymerization shrinkage during curing (during radical polymerization) of dental curable compositions such as filling restorative materials, molecular chains have branched in a dendritic manner, such as hyperbranched polymers and dendrimers. A method using a dendritic polymer has been proposed (Patent Documents 1 and 2). Thereby, the polymerization shrinkage rate at the time of curing can be reduced while maintaining good operability of the dental curable composition.

  In addition to this, the dendritic polymer basically has no room for large polymerization shrinkage accompanying the polymerization like a monomer. Therefore, by using the dendritic polymer, if the blending ratio of the monomer contained in the dental curable composition can be reduced, the polymerization shrinkage rate when the dental curable composition is cured can be reduced.

  Therefore, in order to highly suppress polymerization shrinkage using a dendritic polymer, it is necessary to use a certain amount of dendritic polymer.

  In addition, use of the dendritic polymer for a dental curable composition may be performed for the purpose other than suppression of polymerization shrinkage (patent documents 3 to 5).

Special table 2001-509179 gazette WO03 / 13379 Japanese Patent No. 2702694 JP-A-2005-255681 JP 2009-149585 A

  In the prior art of a dental curable composition containing the above dendritic polymer, the specific composition shown in Examples and the like is that the radical polymerizable monomer component is aliphatic such as triethylene glycol dimethacrylate. In most cases, those belonging to the system are used alone or the aliphatic ones are used in the majority.

  However, as a result of investigations by the present inventors, a large amount of a dendritic polymer is blended in a dental curable composition containing an aliphatic monomer as a main component as a radical polymerizable monomer, thereby causing polymerization shrinkage. Even if the rate is suppressed to a high degree, there is a problem that the cured body has insufficient mechanical strength (bending strength). In particular, in a composition in which a large amount of a filler is blended in the dental curable composition, the mechanical strength that should be originally increased cannot be sufficiently achieved, which is a significant problem. Needless to say, dental curable compositions used as filling restorative materials, etc. are required to have strong mechanical strength that can withstand the load of occlusion, which is designed to be achieved with a large amount of filling material. Thus, the situation in which the mechanical strength is not sufficiently improved even when a large amount of filler is blended is a serious problem.

  In such a background, an object of the present invention is to provide a dental curable composition capable of obtaining high mechanical strength of a cured product while highly suppressing polymerization shrinkage.

  As a result of intensive studies, the inventors of the present invention (C) also in a dental curable composition containing a large amount of a dendritic polymer, as a radical polymerizable monomer, an aromatic one and an aliphatic one are used. By using what mix | blended a thing by a specific ratio, it discovered that said subject was solved and came to complete this invention.

That is, the present invention includes (A) an aromatic radical polymerizable monomer, (B) an aliphatic radical polymerizable monomer, (C) a dendritic polymer, (D) a filler, and (E) polymerization. A dental curable composition comprising an initiator,
The mass ratio of (A) aromatic radical polymerizable monomer and (B) aliphatic radical polymerizable monomer is 55/45 to 85/15,
The blending amount of the (C) dendritic polymer is 5 to 50 parts by mass with respect to 100 parts by mass of the total amount of the (A) aromatic radical polymerizable monomer and the (B) aliphatic radical polymerizable monomer. and a, and (D) the amount of the filler is 150 to 1,500 parts by mass der is, the (B) dendritic polymers, a unit structure represented by the general formula (I) described below, which will be described later general formula ( It is a dental curable composition that is a hyperbranched polymer including a unit structure represented by IIA) and at least one unit structure selected from unit structures represented by the general formula (IIB) described later .

  Further, according to the present invention, as an efficient method for producing the dental curable composition, (A) an aromatic radical polymerizable monomer and (B) an aliphatic radical polymerizable monomer have a mass ratio of 55. 100 parts by mass of radically polymerizable monomer component mixed with / 45 to 85/15 and 5 to 50 parts by mass of (C) dendritic polymer are mixed, and then (D) 150 to 150 of filler. There is also provided a method of mixing 1500 parts by mass and mixing the polymerization initiator (E) at any point in the production process.

  The dental curable composition of the present invention can highly suppress polymerization shrinkage during curing by blending a dendritic polymer. And the radically polymerizable monomer component can improve the mechanical strength of the cured body to be high by the composition in which the aromatic and aliphatic compounds are blended at a specific ratio. Further, as a production method thereof, if a technique in which a radically polymerizable monomer component in which an aromatic group and an aliphatic group are used in combination is mixed with the dendritic polymer prior to the filler, the dental The curable composition for use can be improved to have a higher mechanical strength.

  The dental curable composition of the present invention comprises (A) an aromatic radical polymerizable monomer, (B) an aliphatic radical polymerizable monomer, (C) a dendritic polymer, and (D) a polymerization initiator. Is included. And (C) dendritic polymer is 5-50 mass parts with respect to 100 mass parts of total amounts of (A) aromatic radically polymerizable monomer and (B) aliphatic radically polymerizable monomer. It is blended with a lot of. Thereby, the polymerization shrinkage at the time of hardening can be suppressed highly. The reason is considered as follows.

  First, the dendritic polymer has a shape close to a spherical shape, unlike a string-like general polymer. For this reason, when the polymer is dissolved in the solution, the increase in the viscosity of the dendritic polymer is smaller than that of a general polymer. Therefore, when using a dendritic polymer as a constituent material of the dental curable composition, without greatly changing the filler filling rate and the operability of the dental curable composition, in the dental curable composition, A large amount of dendritic polymer can be added. That is, it is extremely easy to relatively increase the blending ratio of the dendritic polymer as a constituent component in the dental curable composition and to relatively decrease the blending ratio of the polymerizable monomer instead. Yes, this can reduce polymerization shrinkage during curing.

  In addition, such dendritic polymers are particles that finely disperse with good affinity in the cured body, but they are not hard particles such as fillers, but greatly increase the mechanical strength of the resin in which they are blended. It is not an ingredient. However, in the present invention, by using a mixture having a mass ratio of 55/45 to 85/15 of (A) aromatic and (B) aliphatic as the radical polymerizable monomer component, the mechanical properties of the cured product are obtained. Strength is greatly increased.

  Hereinafter, each component which comprises the curable composition of this invention is demonstrated.

(A) Aromatic radical polymerizable monomer The aromatic radical polymerizable monomer can be used without particular limitation as long as it is a radical polymerizable monomer having one or more aromatic rings in the molecule. Although it may have a radical polymerizable group such as vinyl group, styryl group, allyl group, etc., in addition to being more effective in increasing the mechanical strength of the cured product, in terms of biosafety, (meta) It is preferably an acrylate radical polymerizable monomer. Further, from the viewpoint of high polymerizability and mechanical strength of the cured body, a bifunctional to tetrafunctional one is more preferable.

  The aromatic ring present in the molecule may be a condensed polycycle such as a naphthalene ring or an anthracene ring in addition to a benzene ring. The number of such aromatic rings is preferably 2 or more from the viewpoint of mechanical strength. If the number of aromatic rings is too large, the dispersibility of the dendritic polymer may be lowered. Therefore, the number of aromatic rings present in the polymerizable monomer molecule is preferably 10 or less, more preferably 4 or less. . In consideration of the mechanical strength and the dispersibility of the dendritic polymer, the number of aromatic rings present in the molecule is most preferably two.

  Further, such an aromatic ring and a radical polymerizable group are usually connected by a divalent aliphatic hydrocarbon group, and this divalent aliphatic hydrocarbon group may be linear or branched. . Such a divalent aliphatic hydrocarbon group may be one in which an ether bond, an ester bond, a urethane bond or the like is interposed in the chain.

  Furthermore, from the viewpoint of mechanical strength, the aromatic radical polymerizable monomer preferably has a bisphenol A skeleton, and more preferably a compound represented by the general formula (IV).

In the formula, R ^a and R ^b are alkylene groups in which an ether bond may be interposed in the chain. Such an alkylene group may have a substituent such as an oxyalkyl group, a hydroxyl group, and a halogeno group. R ^a and R ^b each preferably have 3 to 15 atoms in the main chain, or the sum of the number of atoms in the main chain of R ^a and R ^b is 6 to 30, and the number of atoms in each main chain is preferably 3 to 10 or the sum of the number of atoms of R ^a and R ^b is more preferably 6 to 20, and the number of atoms of each main chain is 3 to 6, or the number of atoms of the main chain of R ^a and R ^b Is most preferably 6-12.

When the main chain of R ^a and R ^b is too long, the viscosity of the radical polymerizable monomer becomes extremely high, making the paste difficult to handle, and mechanically in the cured body of the dental curable composition. It causes a decrease in strength. On the other hand, when the main chains of R ^a and R ^b are too short, the polymerization shrinkage of the dental curable composition increases. R ^c and R ^d are a hydrogen atom or a methyl group.

  Specific examples of the aromatic radical polymerizable monomer represented by the general formula (IV) include 2,2-bis (methacryloyloxyphenyl) propane and 2,2-bis [4- (3-methacryloyl). Oxy) -2-hydroxypropoxyphenyl] propane, 2,2-bis (4-methacryloyloxyphenyl) propane, 2,2-bis (4-methacryloyloxypolyethoxyphenyl) propane, 2,2-bis (4-methacryloyl) Oxydiethoxyphenyl) propane, 2,2-bis (4-methacryloyloxytetraethoxyphenyl) propane, 2,2-bis (4-methacryloyloxypentaethoxyphenyl) propane, 2,2-bis (4-methacryloyloxydi) Propoxyphenyl) propane, 2 (4-methacryloyloxydi) Toxiphenyl) -2 (4-methacryloyloxytriethoxyphenyl) propane, 2 (4-methacryloyloxydipropoxyphenyl) -2- (4-methacryloyloxytriethoxyphenyl) propane, 2,2-bis (4-methacryloyloxy) Propoxyphenyl) propane, 2,2-bis (4-methacryloyloxyisopropoxyphenyl) propane and acrylates corresponding to these methacrylates; 2-hydroxyethyl methacrylate, 2-hydroxypropyl methacrylate, 3-chloro-2-hydroxypropyl methacrylate Such as methacrylates or vinyl monomers having —OH groups such as acrylates corresponding to these methacrylates, and diisocyanate methylbenzene, 4,4′-diphenyl Diadduct and the like obtained from the addition of the diisocyanate compound having an aromatic group such as Tan diisocyanate.

These polymerizable monomers having an aromatic ring may be used in combination of a plurality of types as necessary.

(B) Aliphatic radical polymerizable monomer As the aliphatic radical polymerizable monomer, a known one made of an aliphatic hydrocarbon compound having a radical polymerizable group can be used without any limitation. It may have a radical polymerizable group such as a vinyl group or an allyl group, but it is more effective in increasing the mechanical strength of the cured product as in the case of the aromatic radical polymerizable monomer, and From the viewpoint of safety, it is preferably a (meth) acrylate radically polymerizable monomer. Further, from the viewpoint of high polymerizability and mechanical strength of the cured body, a bifunctional to tetrafunctional one is more preferable.

  Even when the length of the main chain of the aliphatic radical polymerizable monomer is too long, the viscosity of the polymerizable monomer increases, and the mechanical strength tends to decrease in the cured product of the dental curable composition. become. On the other hand, when the length of the main chain is too short, polymerization shrinkage of the dental curable composition increases. From these viewpoints, the number of atoms in the main chain of the aliphatic radical polymerizable monomer is preferably 9 to 50, and more preferably 12 to 30.

  Further, the aliphatic hydrocarbon group forming the aliphatic radical polymerizable monomer may be one in which an ether bond, an ester bond, a urethane bond or the like is interposed in the chain. Furthermore, the aliphatic hydrocarbon group may be linear or branched, but is more preferably linear from the viewpoint of facilitating dispersion of the dendritic polymer. Further, the aliphatic radical polymerizable monomer may have a functional group such as an oxyalkyl group, a hydroxyl group and a halogeno group as a substituent.

  As the aliphatic radical polymerizable monomer that is suitably used, a compound represented by the general formula (V) is particularly preferable.

In the formula, R ^e is an alkylene group in which an ether bond, an ester bond, or a urethane bond may be interposed in the chain. Such an alkylene group may have a substituent such as an oxyalkyl group, a hydroxyl group and a halogeno group. When the side chain (branched chain part and substituent part) is too large, the alkylene group inhibits the dispersion of the dendritic polymer. Therefore, when the side chain has a side chain, the length is 3 atoms or less from the main chain. Preferably there is. R ^f and R ^g are a hydrogen atom or a methyl group.

  Specific examples of the aliphatic radical polymerizable monomer represented by the general formula (IV) include ethylene glycol dimethacrylate, diethylene glycol dimethacrylate, triethylene glycol dimethacrylate, tetraethylene glycol dimethacrylate, neopentyl glycol. Dimethacrylate, 1,3-butanediol dimethacrylate, 1,4-butanediol dimethacrylate, 1,6-hexanediol dimethacrylate, 1,9-nonanediol dimethacrylate, 1,10-decanediol dimethacrylate and these Acrylate corresponding to methacrylate; methacrylate such as 2-hydroxyethyl methacrylate, 2-hydroxypropyl methacrylate, 3-chloro-2-hydroxypropyl methacrylate Or vinyl monomers having —OH groups such as acrylates corresponding to these methacrylates, and diisocyanate compounds such as hexamethylene diisocyanate, trimethylhexamethylene diisocyanate, diisocyanate methylcyclohexane, isophorone diisocyanate, and methylenebis (4-cyclohexylisocyanate) Diadducts obtained from adducts such as 1,6-bis (methacrylethyloxycarbonylamino) -2,2-4-trimethylhexane; 1,2-bis (3-methacryloyloxy-2-hydroxypropoxy) ethyl Etc.

  These aliphatic radical polymerizable monomers may be used in combination of a plurality of types as required.

  In addition, since the polymer layer of the dental curable composition can be strengthened by forming a hydrogen bond, an aliphatic radical polymerizable monomer having a urethane bond, for example, 1,6-bis (methacrylethyloxycarbonylamino) It is also preferable to contain 2,2,4-trimethylhexane or the like at least a part of the aliphatic radical polymerizable monomer, preferably 30 to 70%.

Further, if necessary, monofunctional (meth) acrylate-based monomethacrylates such as methacrylates such as methyl methacrylate, ethyl methacrylate, isopropyl methacrylate, hydroxyethyl methacrylate, tetrahydrofurfuryl methacrylate, glycidyl methacrylate, and acrylates corresponding to these methacrylates. It is also good to use a monomer.

  The greatest feature of the present invention is the blending ratio of the (A) aromatic radical polymerizable monomer and the (B) aliphatic radical polymerizable monomer. That is, the mass ratio of (A) aromatic radical polymerizable monomer to (B) aliphatic radical polymerizable monomer needs to be 55/45 to 85/15, more preferably 55. / 45 to 75/25, most preferably 60/40 to 67/37.

  A cured product of an aromatic radical polymerizable monomer is generally excellent in mechanical strength as compared with a cured product of an aliphatic radical polymerizable monomer. Therefore, when the mass ratio is not less than the above lower limit value, the mechanical strength of the resin phase is improved, and the mechanical strength of the cured body is improved even when a large amount of dendritic polymer is blended in the dental curable composition. The effect which raises fully is exhibited. On the other hand, many aromatic radical polymerizable monomers have high viscosity, and the aromatic ring part has a structure that prevents the dispersion of the dendritic polymer. From the viewpoint of sufficiently increasing the mechanical strength of the cured product, the mass ratio of the aromatic radical polymerizable monomer needs to be not more than the above upper limit.

(C) Dendritic polymer The dendritic polymer used in the dental curable composition of the present invention includes dendrimer, linear-dendritic polymer, dendrigraft polymer, hyperbranched polymer, star hyperbranched polymer, hypergraft polymer and the like. Is mentioned. Among them, the first three types have a branching degree of 1 and have a defect-free structure, while the latter three types have a random branch structure that may contain defects.

  The branched structure of the dendrimer is formed by chemically reacting a monomer having a polyfunctional group step by step. Examples of the dendrimer synthesis method include a Divergent method for synthesis from the center to the outside and a Convergent method for synthesis from the outside to the center. Examples of dendrimers include amidoamine dendrimers (US Pat. No. 4,507,466 and others) and phenyl ether dendrimers (US Pat. No. 5,041,516 and others). As for the amidoamine dendrimer, a dendrimer having a terminal amino group and a carboxylic acid methyl ester group is commercially available as “Starburst ™ (PAMAM)” from Aldrich. Moreover, the amide amine type | system | group dendrimer with the corresponding terminal synthesize | combined by making the terminal amino group of the amide amine type | system | group dendrimer react with various acrylic acid derivatives and methacrylic acid derivatives can also be used.

  Various phenyl ether dendrimers are described in Journal of American Chemistry, Vol. 112 (1990, pages 7638-7647). As for the phenyl ether dendrimer, those obtained by substituting the terminals with various chemical structures can be used instead of the terminal benzyl ether bond.

  A hyperbranched polymer is a synthetic polymer generally obtained by a one-step polymerization method, unlike a dendrimer that forms a branched structure by precisely controlling a multi-step synthesis reaction. In order to synthesize a large molecule in one step, there are molecular weight distribution and insufficiently branched units. However, compared with the dendrimer, there are great advantages that production is easy and production cost is low. Moreover, if the synthesis conditions are appropriately selected, the degree of branching can be controlled, and molecular design according to the application can be performed. The hyperbranched polymer has, in one molecule, two or more first reaction points corresponding to a branched portion, and a single second reaction point corresponding to a connecting portion and different from the first reaction point. It is synthesized through a one-step synthesis process using monomers (Macromolecules, 29 (1996), 3831-3838).

  As such a synthesis process, for example, a self-condensation method of an ABx type monomer having two kinds of functional groups in one molecule, a method of polycondensation of an A2 type monomer and a B3 type monomer are known (Dend Litic Polymers-A highly functional world where multi-branched structures expand, NTS Corporation (2005)). And a branched structure is formed at a stretch by these methods. In the description of the synthesis method described above, “A” and “B” shown in capital letters indicate different functional groups, and the Arabic numerals shown in combination with “A” and “B” are 1 indicates the number of functional groups in one molecule.

  Further, as a method for obtaining a hyperbranched polymer by polymerizing a compound having a functional group capable of initiating polymerization and a vinyl group in one molecule, a self-condensable vinyl polymerization method (SCVP method) is known (Science, 269, 1080 (1995)). In addition, as a method of synthesizing a hyperbranched polymer in which an initiator fragment is incorporated into a produced polymer by polymerizing a molecule having a plurality of polymerizable groups using a large amount of initiator, the initiator fragment-containing radical weight is synthesized. Legal (IFIRP) is known (J. Polymer. Sci .: Part A: Polym. Chem., 42, 3038 (2003)).

  The structure of the hyperbranched polymer has various structures depending on the chemical modification of the surface functional group of the ABx type monomer to be used or the obtained polymer. As the hyperbranched polymer, from the viewpoint of classification of the skeleton structure, hyperbranched polycarbonate, hyperbranched polyether, hyperbranched polyester, hyperbranched polyphenylene, hyperbranched polyamide, hyperbranched polyimide, hyperbranched polyamideimide, hyperbranched polysiloxane, Examples include hyperbranched polycarbosilane. In addition, as the end groups that these hyperbranched polymers have, alkyl groups, phenyl groups, heterocyclic groups, (meth) acryl groups, allyl groups, styryl groups, hydroxyl groups, amino groups, imino groups, carboxyl groups, halogeno groups, An epoxy group, a thiol group, a silyl group, etc. are mentioned. Further, these end groups can be further chemically modified to give functional groups according to the purpose to the hyperbranched polymer surface.

  In the dental curable composition of the present invention, only one of these dendritic polymers may be used alone, or two or more kinds of dendritic polymers may be used in combination. Of the dendritic polymers listed above, dendrimers or hyperbranched polymers can be particularly preferably used.

  Since the dendritic polymer has little entanglement between molecules and exhibits fine particle behavior, the dendritic polymer can be finely dispersed with high affinity without increasing the viscosity of the dental curable composition containing the dendritic polymer. For this reason, when a certain amount of dendritic polymer is blended in the dental curable composition, the polymerization shrinkage at the time of curing can be greatly reduced. Further, the molecular weight of the dendritic polymer is not particularly limited, but the weight average molecular weight is preferably 5000 or more, more preferably 10,000 or more, as measured by GPC (Gel Permeation Chromatography) method. Most preferably, it is 15000 or more. In addition, the upper limit of the weight average molecular weight is not particularly limited, but if it is too large, the operability of the dental curable composition is lowered when the amount of the dendritic polymer is greatly changed. There is. For this reason, the weight average molecular weight is preferably 200000 or less in practice, more preferably 100000 or less, and most preferably 80000 or less.

  When the molecular weight is within the above range, a spherical dendritic polymer having a hydrodynamic average diameter of about 1 nm to about 40 nm in tetrahydrofuran (THF) measured by a dynamic light scattering method can be obtained. The hydrodynamic average diameter is preferably in the range of 3 nm to 20 nm, and more preferably in the range of 5 nm to 15 nm.

  The blending amount of the dendritic polymer contained in the dental curable composition is not particularly limited, but the total amount of (A) aromatic radical polymerizable monomer and (B) aliphatic radical polymerizable monomer. It is necessary to set it as 5-50 mass parts with respect to 100 mass parts, It is more preferable to set it as 8 mass parts-40 mass parts, and it is most preferable to set it as 8 mass parts-30 mass parts. By setting the blending amount of the dendritic polymer to 5 parts by mass or more, it becomes easy to further reduce the polymerization shrinkage rate when the dental curable composition is cured. Moreover, it becomes easy to ensure the mechanical strength of hardened | cured material while preventing deterioration of operativity by the compounding quantity of a dendritic polymer being 50 mass parts or less.

  As the dendritic polymer used in the dental curable composition of the present invention, the various dendritic polymers described above can be used, but at least one selected from three branched parts and four branched parts. It is preferable to have a network structure (a network-like multi-branch structure) including the branch parts and the connection parts connecting the branch parts. A typical example of the dendritic polymer having such a network structure is a hyperbranched polymer. In addition, since the movement of the molecular chain constituting the network structure is restricted and the entanglement between the molecular chains is reduced as the branch in the network structure is further developed, the dental curable composition Even if the blending ratio of the dendritic polymer is increased, it becomes easier to suppress the increase in viscosity.

  In addition, the end portion of the network structure may have a reactive functional group such as a group having a reactive unsaturated bond, an amino group, or a hydroxyl group, and substantially has a reactive functional group. It does not have to be. In addition, when it has substantially no reactive functional group, the terminal part of network structure will be occupied by non-reactive functional groups, such as an alkyl group. Here, “substantially having no reactive functional group” means not only the case where there is no reactive functional group at the end of the network structure, but also the synthesis of a dendritic polymer having a network structure. It also means that a slightly reactive functional group is introduced into the end portion of the network structure due to occasional side reactions or impurities in the reaction system.

  When the reactive functional group remains in the cured product after the dental curable composition is cured, when the cured product is exposed to food or drink in the oral environment, or exposed to natural light or indoor light, The reactive functional group remaining in the cured product reacts with food and drink, natural light, and room light, so that the cured product is easily colored or discolored. However, when the end portion of the network structure does not substantially have a reactive functional group, it is extremely easy to suppress the occurrence of coloring and discoloration of such a cured product.

  In addition, the internal part of network structure may also have a reactive functional group. However, the reactive functional group located in the inner part of the network structure is likely to cause coloring or discoloration in the same manner as the reactive functional group located in the terminal part. It is preferably substantially free of groups.

  In the network structure constituting the hyperbranched polymer, the number of branches is generally 3 or 4 branches. The three-branched branched portion (three-branched portion) is preferably formed of a nitrogen atom, a trivalent cyclic hydrocarbon group or a trivalent heterocyclic group, and the four-branched branched portion (four-branched portion) is: It is preferably formed of a carbon atom, a silicon atom, a tetravalent cyclic hydrocarbon group or a tetravalent heterocyclic group. The (trivalent or tetravalent) cyclic hydrocarbon group can be broadly classified as an aromatic hydrocarbon group exemplified by a (trivalent or tetravalent) benzene ring and the like, and (trivalent or tetravalent). And an alicyclic hydrocarbon group exemplified by a (cyclovalent) cyclohexane ring. As the (trivalent or tetravalent) heterocyclic group, a known heterocyclic group can be used. In addition, as a trivalent heterocyclic group, what is shown to following Structural formula 1 can also be mentioned, for example.

Moreover, it is preferable that the connection part which connects branch parts is any 1 type of bivalent group or atom selected from following Structural formula group X. Here, in Structural Formula Group X, R ¹¹ is an aromatic hydrocarbon group or an alkylene group having 40 or less carbon atoms, and n is an integer selected from the range of 1 to 9. Note that two or more of the plurality of connection portions coupled to one branch portion may be the same, or all the connection portions coupled to one branch portion may be different from each other.

  Moreover, as a general example of the terminal part of such network structure, a hydrogen atom, a halogen atom (-F, -Cl, -Br, or -I), a styryl group, an epoxy group, a glycidyl group, the following structural formula group Z Any one monovalent group selected from: a monovalent group represented by the general formula (IIA) described later; a monovalent group represented by the general formula (IIB) described later; a monovalent cyclic hydrocarbon group; Or a monovalent | monohydric heterocyclic group etc. are mentioned. Here, the group excluding the hydrogen atom and the halogen atom in the terminal portion may be further chemically modified. In the monovalent cyclic hydrocarbon group and monovalent heterocyclic group, the hydrogen atom bonded to the ring may be substituted with a halogen atom, a carboxyl group, an amino group, a hydroxyl group, or a monovalent carboxylic acid ester. . In addition, the monovalent cyclic hydrocarbon group is roughly classified into an aromatic hydrocarbon group exemplified by a monovalent benzene ring and an alicyclic hydrocarbon group exemplified by a monovalent cyclohexane ring. Can be mentioned.

In Structural Formula Group Z, R ¹² is a monovalent aromatic hydrocarbon group or an alkyl group having 40 or less carbon atoms, and R ¹³ is a divalent aromatic hydrocarbon group or an alkylene having 40 or less carbon atoms. It is a group. Further, in the group represented by the structural formula group Z, when both R ¹² and R ¹³ are included, the structures of both may be the same or different from each other except for the valence.

  Specific examples of dendritic polymers that can be suitably used in the dental curable composition of the present invention include dendritic polymers having a network structure formed by bonding unit structures represented by the following general formula (i) to each other. Polymers.

Here, in the general formula (i), A represents a single bond linking the C and ^{R 1} (i.e., state and C and ^{R 1} is simply attached at bond σ),> C = O, -O —, —COO—, or —COO—CH ₂ —, wherein R ¹ is a divalent saturated aliphatic hydrocarbon group or a divalent aromatic hydrocarbon group, and R ² is a hydrogen atom Or Y is a group represented by the following general formula (iii) or a group represented by the following general formula (iib). When the network structure excluding the terminal portion is composed of the unit structure represented by the general formula (i), the unit structure represented by the general formula (i) constituting the network structure is substantially only one type. It may be comprised from two or more types.

  In the group represented by the following general formula (ia) and the group represented by the following general formula (iib), a is 0 or 1. Here, the unit structure represented by the general formula (i) is a unit structure having four bonds when Y is a group represented by the general formula (ia), and Y is represented by the general formula (iib). In the case of the group shown, the unit structure has three bonds. From the viewpoint of easily suppressing an increase in viscosity when the blending ratio of the hyperbranched polymer to the dental curable composition is increased, Y is preferably a group represented by the general formula (ia).

  Examples of the terminal portion of the network structure formed by the unit structure represented by the general formula (i) include various atoms or various groups exemplified as general examples of the terminal portion described above.

R ¹ constituting the unit structure represented by the general formula (i) is a divalent saturated aliphatic hydrocarbon group or a divalent aromatic hydrocarbon group. Here, the divalent saturated aliphatic hydrocarbon group may be either a chain or a ring. Moreover, although carbon number is not specifically limited, The inside of the range of 1-5 is preferable, and the inside of the range of 1-2 is more preferable. By setting the number of carbon atoms to 5 or less, the molecular chain portion represented as R ¹ is shortened, so that the entanglement between the radically polymerizable monomer constituting the dental curable composition and the hyperbranched polymer is further increased. It can suppress and can further suppress that the viscosity of a liquid or paste-like dental curable composition increases. Examples of the divalent chain saturated aliphatic hydrocarbon group include a methylene group, an ethylene group, a propylene group, and a butylene group. Examples of the divalent cyclic saturated aliphatic hydrocarbon group include a cyclopropylene group and a cyclobutylene group.

  In addition, the divalent aromatic hydrocarbon group includes a monocyclic ring containing one benzene ring, a monocyclic ring containing two or more benzene rings and having a condensed ring structure, or a condensed ring structure containing two or more benzene rings. Any of these may be used. The number of benzene rings contained in the divalent aromatic hydrocarbon group is not particularly limited, but is preferably in the range of 1 to 2, and the number of benzene rings is particularly preferably 1 (in other words, divalent aromatic The group hydrocarbon group is particularly preferably a phenylene group). When the number of benzene rings is 2 or less, the entanglement between the radical polymerizable monomer constituting the dental curable composition and the hyperbranched polymer is further suppressed, and the viscosity of the dental curable composition is reduced. The increase can be further suppressed. Examples of the divalent aromatic hydrocarbon group include a naphthylene group and a biphenylene group in addition to the phenylene group described above.

It should be noted that, among the R ¹ exemplified above, especially a phenylene group is preferable. Even if the phenylene group greatly changes the blending amount of the hyperbranched polymer added to the dental curable composition, the operability when performing dental treatment using the dental curable composition, Little adverse effect on mechanical properties. For this reason, it becomes easy to design the composition of the dental curable composition without being restricted by operability and mechanical properties. Also, when a phenylene group as R ^1, it is possible to improve the mechanical strength of the cured product obtained by curing the dental curable composition.

  Among the hyperbranched polymers having a network structure formed by the unit structure represented by the general formula (i), a unit structure represented by the following general formula (I) and And hyperbranched polymers including a unit structure represented by the formula (IIA) and at least one unit structure selected from the unit structures represented by the following general formula (IIB). Here, the unit structure represented by the general formula (I) is a unit structure having four bonds constituting the network structure itself, and the unit structures represented by the general formula (IIA) and the general formula (IIB) are The unit structure constituting the terminal portion (terminal group) of the network structure. In the following description, when referring only to a hyperbranched polymer having a network structure composed of these unit structures, it is referred to as “hyperbranched polymer A”.

Here, in the general formula (I), A, R ¹ and R ² are the same as A, R ¹ and R ² shown in the general formula (i).

In general formula (IIA) and general formula (IIB), R ³ , R ⁴ and R ⁵ are each a hydrogen atom, an alkyl group having 1 to 5 carbon atoms constituting the main chain, or a main chain. It is an alkoxycarbonyl group having 1 to 5 carbon atoms, an aryl group, or a cyano group. In general formula (IIB), R ⁶ is an alkylene group having 4 to 10 carbon atoms constituting the main chain.

R ³ , R ⁴ , and R ⁵ constituting the general formula (IIA) and the general formula (IIB) particularly constitute an alkyl group having 1 to 5 carbon atoms constituting the main chain and the main chain. More preferably, it is an alkoxycarbonyl group having 1 to 5 carbon atoms or a cyano group. Examples of the alkyl group include a methyl group, an ethyl group, and a propyl group. Examples of the alkoxycarbonyl group include a methoxycarbonyl group, an ethoxycarbonyl group, and a propoxycarbonyl group. Examples of the aryl group include, for example, And a phenyl group. For alkyl groups and alkoxycarbonyl groups, the number of carbon atoms constituting the main chain is 5 or less, in particular, by using a methyl group or a methoxycarbonyl group, the main chain is shortened. The entanglement between the radically polymerizable monomer constituting the product and the hyperbranched polymer A can be further suppressed, and the viscosity of the dental curable composition can be further suppressed from increasing.

  Moreover, you may substitute a part of hydrogen atom of an alkyl group, an alkoxycarbonyl group, and an aryl group with a substituent. The substituent is not particularly limited as long as it does not contain a structure / group (reactive unsaturated bond, amino group, hydroxyl group, etc.) that causes coloration or discoloration. For example, it has 1 carbon atom such as a methyl group. An alkoxyl group having 1 to 3 carbon atoms such as 1 to 3 alkyl groups and a methoxy group can be exemplified. In addition, about an alkyl group and an alkoxyl group, since the side chain comprised by a substituent becomes short by making it carbon number 3 or less, especially a methyl group or a methoxy group, a dental curable composition is comprised. It is possible to further suppress the entanglement between the radical polymerizable monomer and the hyperbranched polymer A and further increase the viscosity of the dental curable composition.

R ⁶ constituting the general formula (IIB) is an alkylene group having 4 to 10 carbon atoms constituting the main chain. Examples of the alkylene group include a butylene group, a pentylene group, and a nonylene group. Moreover, you may substitute some hydrogen atoms of an alkylene group by a substituent. The substituent is not particularly limited as long as it does not contain a structure / group (reactive unsaturated bond, amino group, hydroxyl group, etc.) that causes coloration or discoloration. For example, it has 1 carbon atom such as a methyl group. An alkoxyl group having 1 to 3 carbon atoms such as 1 to 3 alkyl groups and a methoxy group can be exemplified. Note that by the number of carbon atoms constituting the main chain of the alkylene group with 4 or more, it is possible to suppress the distortion of the formed ring and a carbon atom bonded with both ends of the R ⁶ and R ^6. For this reason, it is possible to suppress the possibility of causing coloring by reacting with surrounding substances due to the ring becoming distorted and destabilized.

  Further, the main chain is shortened by setting the number of carbon atoms constituting the main chain of the alkylene group to 10 or less, or the number of carbon atoms of the alkyl group and alkoxyl group selected as a substituent is 3 or less, particularly Since the side chain constituted by the substituent is shortened by making it a methyl group or a methoxy group, the entanglement between the radically polymerizable monomer constituting the dental curable composition and the hyperbranched polymer A Can be further suppressed, and an increase in the viscosity of the dental curable composition can be further suppressed. The alkylene group is particularly preferably a pentylene group from the viewpoint of achieving both suppression of ring distortion and suppression of viscosity.

  The four bonds of the first unit structure represented by the general formula (I) include the first unit structure represented by the general formula (I), or the general formula (IIA) and the general formula (IIB). A second unit structure selected from two types of unit structures represented by Further, when the hyperbranched polymer A includes other unit structures (third unit structure) other than the general formula (I), the general formula (IIA), and the general formula (IIB), A third unit structure can also be attached.

  Here, a network structure is formed by bonding the first unit structures through at least one of the four bonds. Further, the second unit structure, which is a terminal group that divides the network structure, can be bonded to a maximum of three bonds out of the four bonds in the first unit structure. Here, the content ratio (molar ratio) between the first unit structure and the second unit structure contained in the hyperbranched polymer A is not particularly limited, but may be in the range of 3: 7 to 7: 3. Preferably, it is more preferably in the range of 4: 6 to 6: 4. By setting the molar ratio within the above range, a network structure having moderate branching can be formed, and a significant increase in the viscosity of a solution in which the hyperbranched polymer A is dispersed in a solvent can be suppressed.

  When the hyperbranched polymer A also includes a third unit structure having two or more bonds, the hyperbranched polymer A also depends on the content ratio of the third unit structure to the first unit structure and the second unit structure. However, the content ratio (molar ratio) between the first unit structure and the second unit structure is within a range in which a network structure can be formed, and is preferably selected from a range of 1: 9 to 7: 3, for example. It is more preferable to select from the range of 2: 8 to 7: 3. In this case, the content ratio (molar ratio) between the first unit structure and the second unit structure is more preferably in the range of 3: 7 to 7: 3, and 4: 6 to 6: A range of 4 is particularly preferable.

  A hyperbranch including the unit structure represented by the general formula (I) as described above and at least one unit structure selected from the unit structure represented by the general formula (IIA) and the unit structure represented by the general formula (IIB) The polymer A does not contain a reactive unsaturated bond, or a reactive functional group such as an amino group or a hydroxyl group in the molecule. In addition, the radical polymerizable monomer loses a reactive functional group by a polymerization reaction. For this reason, the dental curable composition of the present embodiment using the hyperbranched polymer A is colored even if it is cured and exposed to food or drink in the oral cavity environment or exposed to natural light or indoor light. And discoloration hardly occurs.

  Further, the hyperbranched polymer A comprising a unit structure represented by the general formula (I) and at least one unit structure selected from the unit structure represented by the general formula (IIA) and the unit structure represented by the general formula (IIB) is: And having a network structure based on the unit structure represented by the general formulas (IIA) and (IIB). That is, the movement of both ends of the branched molecular chain is very restricted. For this reason, it is very difficult for the adjacent branch portions to be entangled with each other, and the viscosity of the dental curable composition is hardly increased.

  The hyperbranched polymer A suitably used for the dental adhesive composition of the present embodiment has a unit structure represented by the following general formula (IIIA) as a third unit structure, and a general formula (IIIB) below. The unit structure shown, the unit structure shown by the following general formula (IIIC), and at least one unit structure selected from the unit structure shown by the following general formula (IIID) may be included. In addition, the 3rd unit structure shown by the following general formula (IIIA) and the following general formula (IIID) may be contained in the hyperbranched polymer A as an impure component at the time of synthesize | combining the hyperbranched polymer A.

Here, in general formula (IIIA), general formula (IIIB), general formula (IIIC) and general formula (IIID), A, R ¹ and R ² are A, R ¹ and R shown in general formula (i). ^Same as ² . In the general formula (IIIB), R ⁷ is a monovalent saturated aliphatic hydrocarbon group or a monovalent aromatic hydrocarbon group. In the general formula (IIIC), R ⁸ is a tetravalent A saturated aliphatic hydrocarbon group or a tetravalent aromatic hydrocarbon group, and B in the general formula (IIID) is —COO—CH═.

  Moreover, since the 3rd unit structure shown by general formula (IIIA) and general formula (IIID) contains a reactive unsaturated bond, it is easy to accelerate | stimulate coloring and discoloration of hardened | cured material. Therefore, the hyperbranched polymer is a first unit structure represented by the general formula (I), and a second unit selected from the unit structure represented by the general formula (IIA) and the unit structure represented by the general formula (IIB). In addition to the structure, when the third unit structure represented by the general formulas (IIIA) and (IIID) is also included, the ratio of the third unit structure represented by the general formulas (VA) and (VD) in the total unit structure is 20 mol% or less, preferably 10 mol% or less, more preferably 5 mol% or less.

  Further, a third unit structure having two bonds as exemplified in general formula (IIIA), general formula (IIIB) and general formula (IIID), and a first unit represented by general formula (I) The ratio to the structure is preferably in the range of 6: 4 to 0:10, more preferably in the range of 4: 6 to 0:10, and most preferably 0:10. By setting the ratio between the third unit structure having two bonds and the first unit structure represented by the general formula (I) within the above range, a network structure having moderate branching can be formed. Moreover, the remarkable increase in the viscosity of the dental curable composition containing the hyperbranched polymer A can be suppressed.

R ⁷ constituting the third unit structure shown in the general formula (IIIB) and R ⁸ constituting the third unit structure shown in the general formula (IIIC) have the same structure as R ¹ except that the valence is different. Can be used.

  The second unit structure represented by the general formula (IIA) and the general formula (IIB) is a raw material component (for example, used in the synthesis process of the hyperbranched polymer A used in the dental curable composition of the present embodiment). , Monomer, polymerization initiator, end group modifier, etc.). Although it does not specifically limit as the said raw material component, For example, a well-known polymerization initiator is mentioned, Preferably, the azo polymerization initiator disclosed by international publication 2010/126140 is mentioned. However, in the dental curable composition of the present embodiment, after synthesizing the hyperbranched polymer A among the raw material components, the polymerization initiator or the azo polymerization initiator listed above, the general formula (IIA) It is preferable to employ one that can take the structure shown in the general formula (IIB). For this reason, the dental curable composition of the present embodiment is less likely to be colored or discolored.

  Specific examples of the second unit structure represented by the general formula (IIA) include the following structural formulas A to K. Specific examples of the second unit structure represented by the general formula (IIB) Includes the following structural formulas L to M. The second unit structures represented by these structural formulas A to M are particularly suitable in terms of availability of the hyperbranched polymer A.

  Examples of the hyperbranched polymer A having the molecular structure as described above include the following (1) to (6).

(1) T.W. Hirano et al. , J .; Appl. Polym. Sci. , 2006, 100, 664-670 (A: single bond for bonding C and R ¹ , R ¹ : phenylene group, R ² : hydrogen atom, R ³ : —CH ₃ , R ^{4 _{: -CH 3, R 5: -COOCH}} 3). In addition, as a commercially available hyperbranched polymer having substantially the same molecular structure, HYPERTECH (registered trademark) / HA-DVB-500 (manufactured by Nissan Chemical Industries, Ltd., molecular weight by GPC method: 48000, hydrodynamic average diameter of 11.7 nm) (In THF)).

(2) T.W. Hirano et al. , Macromol. Chem. Phys. , 205, 206, 860-868 (A: —COO—, R ¹ : — (CH ₂ ) ₂ —, R ² : —CH ₃ , R ³ : —CH ₃ , R ⁴ : _{^{-CH 3, R 5: -COOCH 3}} ). In addition, as a commercially available hyperbranched polymer having substantially the same molecular structure, HYPERTECH (registered trademark) manufactured by Nissan Chemical Industries, Ltd .; HA-DMA-200 (molecular weight 22000 by GPC method, hydrodynamic average diameter 5.2 nm ( in THF)), HA-DMA-50 (sample sample, molecular weight 4000 by GPC method), and HA-DMA-700 (sample sample, molecular weight 67000 by GPC method).

(3) T.W. Sato et al. , Macromolecules, 2005, 38, 1627-1632 (A: —COO—, R ¹ : — (CH ₂ ) ₄ —, R ² : —H, R ³ : —CH ₃ , R ^{4. _{: -CH 3, R 5: -COOCH}} 3).

(4) T.W. Sato et al. , Macromole. Mater. Eng. , 2006, 291, 162-172, hyperbranched polymer. The hyperbranched polymer also includes a third unit structure represented by the general formula (IIIB). Here, the first unit structure shown in the general formula (I) is a single bond that binds A: C and R ¹ , R ¹ : phenylene group, R ² : -H, and is shown in the general formula (IIIB) The third unit structure is A: —COO—, R ⁷ : ethyl group, R ² : —H. The second unit structure shown in the general formula (IIA) is R ³ : —CH ₃ , R ⁴ : —CH ₃ , R ⁵ : —COOCH ₃ .

(5) T.W. Sato et al. , Polym. Int. Hyperbranched polymer disclosed in 2004, 53, 1138-1144. The hyperbranched polymer also includes a third unit structure represented by the general formula (IIIB). Here, the first unit structure shown in the general formula (I) is A: —COO—, R ¹ :—( CH ₂ ) ₄ —, R ² : —H, and the third unit structure shown in the general formula (IIIB). the unit structure of a: ^-O-, R 7: 2- methylpropyl ^group, R 2: is -H. The second unit structure shown in the general formula (IIA) is R ³ : —CH ₃ , R ⁴ : —CH ₃ , R ⁵ : —CN.

(6) T.W. Sato et al. , J .; Appl. Polym. Sci. Hyperbranched polymer disclosed in 2006, 102, 408. This hyperbranched polymer also includes a third unit structure represented by the general formula (VD). Here, the first unit structure shown in the general formula (I) is A: —COO—CH ₂ —, R ¹ : phenylene group (two bonds are ortho positions), R ² : —H, The third unit structure represented by the formula (IIID) is A: —COO—CH ₂ —, B: —COO—CH═, R ¹ : phenylene group (two bonds are ortho positions), R ² : —H It is. The second unit structure shown in the general formula (IIA) is R ³ : —CH ₃ , R ⁴ : —CH ₃ , R ⁵ : —COOCH ₃ .

At present, various commercially available hyperbranched polymers including hyperbranched polymer A include “Hybrane” (registered trademark) of DSM, in addition to “HYPERTECH” (registered trademark) series of Nissan Chemical Industries, Ltd. Trademark), “Boltorn” (registered trademark) of Perstop, and the like. “HYPERTECH”, “Hybrane”, and “Bolton” are sold in different grades with different molecular weights, viscosities, and terminal groups. Here, as for the HYPERTECH series, other than the hyperbranched polymer A, as a hyperbranched polymer having a network structure formed by the unit structure represented by the general formula (i), HPS-200 (Y is the general formula (iib)) In which a network structure is formed by a unit structure having three bonds).

(D) Filler The dental curable composition of the present invention can increase the effect of suppressing polymerization shrinkage of the dental curable composition and improve operability by incorporating a filler. , Mechanical strength can be improved. As such a filler, one or more selected from inorganic fillers, organic fillers, and organic-inorganic composite fillers can be used as appropriate. In a composition that contains a large amount of inorganic fillers that are incompatible with radically polymerizable monomers, if a large amount of dendritic polymer is added, the effect of improving the mechanical strength can be sufficiently exerted. It is easy to disappear. Therefore, such a composition is particularly preferable because the effect of the present invention in which an aromatic monomer is used in combination at a specific mass ratio as the radical polymerizable monomer is more prominent.

  Examples of inorganic fillers preferably used in the present invention include, for example, periodic groups I, II, III, IV, transition metals and oxides thereof, fluorides, carbonates, sulfates, silicates and hydroxides. , Chlorides, sulfites, phosphates, and mixtures and complex salts thereof. More specifically, amorphous silica, quartz, alumina, titania, zirconia, barium oxide, yttrium oxide, lanthanum oxide, ytterbium oxide and other inorganic oxides, silica-zirconia, silica-titania, silica-titania-barium oxide , Composite oxides such as silica-titania-zirconia, borosilicate glass, aluminosilicate glass, fluoroaluminosilicate glass, inorganic fluorides such as barium fluoride, strontium fluoride, yttrium fluoride, lanthanum fluoride, ytterbium fluoride, Examples thereof include inorganic carbonates such as calcium carbonate, magnesium carbonate, strontium carbonate and barium carbonate, and inorganic sulfates such as magnesium sulfate and barium sulfate.

  Examples of the organic filler include polymethyl (meth) acrylate, polyethyl (meth) acrylate, methyl (meth) acrylate / ethyl (meth) acrylate copolymer, methyl (meth) acrylate / butyl (meth) acrylate copolymer, or Non-crosslinkable polymers such as methyl (meth) acrylate / styrene copolymer, methyl (meth) acrylate / ethylene glycol di (meth) acrylate copolymer, methyl (meth) acrylate / triethylene glycol di (meth) acrylate A crosslinkable polymer such as a polymer or a copolymer of methyl (meth) acrylate and a butadiene monomer can be used.

  Organic-inorganic composite fillers, for example, pulverize a cured product obtained by curing a polymerization curable composition containing a polymerizable monomer and an inorganic filler, or polymerize in an agglomeration gap between primary particles of inorganic filler agglomerated particles. It can be produced by polymerizing the polymerizable monomer after allowing the polymerizable monomer to enter.

  As the raw material filler of the organic-inorganic composite filler (hereinafter abbreviated as “composite filler raw material filler”), any known filler that can be used as a dental composite restorative material can be used without any limitation. As an example of the composite filler raw material filler which can be used suitably, what was illustrated as an inorganic filler of the term of a filler is mentioned. These polymerizable monomers may be used alone or in combination with different types.

  Also, any known polymerizable monomer that can be used as a dental composite restorative material can be used for the organic-inorganic composite filler raw material polymerizable composition (hereinafter abbreviated as “composite filler raw material monomer”) without any limitation. It is. Examples of the composite filler raw material monomer that can be suitably used include those exemplified in the description of the aromatic radical polymerizable monomer and the aliphatic radical polymerizable monomer. These polymerizable monomers may be used alone or in combination with different types.

  The composite filler is cured by polymerizing the composite filler raw material monomer, which is a component thereof, using a polymerization initiator, and a known polymerization initiator is not particularly limited as the polymerization initiator. Generally, different types of polymerization initiators are used depending on the polymerization means of the polymerizable monomer. Examples of polymerization means include those based on light energy such as ultraviolet rays and visible light, those based on chemical reaction between peroxides and accelerators, and those based on heating. Various polymerization initiators shown below depending on the polymerization means employed. A suitable polymerization initiator may be appropriately selected from the above, but it is preferable to use a thermal polymerization initiator from the viewpoint that a cured product having a lower yellowness can be obtained. As an example of a polymerization initiator, what was illustrated by the term of the polymerization initiator is mentioned. These polymerization initiators may be used alone or in combination of two or more. The addition amount of the polymerization initiator may be selected according to the purpose, but is usually 0.01 to 10 parts by weight, more preferably 0.1 to 5 parts by weight with respect to 100 parts by weight of the composite filler raw material monomer. Used at a rate of

  In the polymerization of the composite filler raw material monomer, a known additive may be blended before the polymerization within a range not impairing the effects of the present invention. Examples of such additives include pigments, ultraviolet absorbers, and fluorescent pigments.

  The composite filler may be subjected to washing, decolorization, and surface treatment prior to mixing with an inorganic filler or a polymerizable monomer. In general, decolorization is performed by dispersing the organic-inorganic composite filler in an appropriate solvent, dissolving and stirring the peroxide, and optionally heating, and a known peroxide is preferably used as the peroxide. it can.

  The filler is hydrophobized with a surface treatment agent typified by a silane coupling agent, so that the affinity with the polymerizable monomer, the dispersibility in the polymerizable monomer, the mechanical strength of the cured product, and Water resistance can be improved. Examples of silane coupling materials include methyltrimethoxysilane, methyltriethoxysilane, methyltrichlorosilane, dimethyldichlorosilane, trimethylchlorosilane, vinyltrichlorosilane, vinyltriethoxysilane, vinyltris (β-methoxyethoxy) silane, γ- Examples include methacryloyloxypropyltrimethoxysilane, γ-chloropropyltrimethoxysilane, γ-glycidoxypropyltrimethoxysilane, and hexamethyldisilazane.

  The refractive index of the filler described above is not particularly limited. For general dental use, those having a refractive index at 25 ° C. in the range of 1.4 to 1.7 are preferably used. Moreover, there is no restriction | limiting in particular also about a shape or a particle diameter. The shape or particle diameter is appropriately selected and used, but the average particle diameter is usually 0.001 to 100 μm. Further, in the case of an inorganic filler, 0.001 to 20 μm, particularly 0.01 to 10 μm is preferable, and in the case of an organic filler, 0.1 μm to 10 μm, particularly 0.1 μm to 1 μm is preferable. In this case, 1 μm to 100 μm, particularly 5 μm to 50 μm is preferable. Further, among the fillers described above, it is particularly preferable to use a spherical filler since the surface smoothness of the resulting cured body is increased and an excellent repair material can be obtained.

The blending amount of these fillers is required for dental filling and restorative materials, in addition to the strength of the cured body and small polymerization shrinkage, the viscosity (operability) when mixed with a polymerizable monomer and the cured body Although it may be appropriately determined in consideration of mechanical properties, in general, the total amount of (A) aromatic radical polymerizable monomer and (B) aliphatic radical polymerizable monomer is 100 parts by mass. Is used in the range of 150 to 1500 parts by mass. In particular, when the dendritic polymer is blended with the dental curable composition, which is the object of the present invention, the problem that the mechanical strength that should be enhanced by blending the filler is not sufficiently exhibited is as described above. Since it is remarkable when the material is blended in a larger amount, the blending amount of the filler is preferably 180 to 600 parts by mass.

(E) Polymerization initiator As the polymerization initiator, known ones used as dental materials can be used without any limitation, and from the viewpoint of ease of handling when the dental curable composition is handled in the oral cavity, photopolymerization is performed. Initiators are preferred. Representative photopolymerization initiators include a combination of α-diketone and tertiary amine, a combination of acylphosphine oxide and tertiary amine, a combination of thioxanthone and tertiary amine, α-aminoacetophenone And photopolymerization initiators such as combinations of amines and tertiary amines, combinations of aryl borates and photoacid generators.

  Examples of various compounds suitably used for the above various photopolymerization initiators include camphorquinone, benzyl, α-naphthyl, acetonaphthene, naphthoquinone, p, p′-dimethoxybenzyl, p, p. Examples include '-dichlorobenzylacetyl, 1,2-phenanthrenequinone, 1,4-phenanthrenequinone, 3,4-phenanthrenequinone, and 9,10-phenanthrenequinone.

  Tertiary amines include N, N-dimethylaniline, N, N-diethylaniline, N, N-di-n-butylaniline, N, N-dibenzylaniline, N, N-dimethyl-p-toluidine, N , N-diethyl-p-toluidine, N, N-dimethyl-m-toluidine, p-bromo-N, N-dimethylaniline, m-chloro-N, N-dimethylaniline, p-dimethylaminobenzaldehyde, p-dimethyl Aminoacetophenone, p-dimethylaminobenzoic acid, p-dimethylaminobenzoic acid ethyl ester, p-dimethylaminobenzoic acid amyl ester, N, N-dimethylanthranilic acid methyl ester, N, N-dihydroxyethylaniline, N, N-dihydroxyethyl-p-toluidine, p-dimethylaminophenethyl alcohol p-dimethylaminostilbene, N, N-dimethyl-3,5-xylidine, 4-dimethylaminopyridine, N, N-dimethyl-α-naphthylamine, N, N-dimethyl-β-naphthylamine, tributylamine, tripropylamine , Triethylamine, N-methyldiethanolamine, N-ethyldiethanolamine, N, N-dimethylhexylamine, N, N-dimethyldodecylamine, N, N-dimethylstearylamine, N, N-dimethylaminoethyl methacrylate, N, N- Examples include diethylaminoethyl methacrylate and 2,2 ′-(n-butylimino) diethanol. These can be used individually or in mixture of 2 or more types.

  Acylphosphine oxides include benzoyldiphenylphosphine oxide, 2,4,6-trimethylbenzoyldiphenylphosphine oxide, 2,6-dimethoxybenzoyldiphenylphosphine oxide, 2,6-dichlorobenzoyldiphenylphosphine oxide, 2,3,5, Examples include 6-tetramethylbenzoyldiphenylphosphine oxide.

  Examples of thioxanthones include 2-chlorothioxanthone and 2,4-diethylthioxanthone.

  Examples of α-aminoacetophenones include 2-benzyl-dimethylamino-1- (4-morpholinophenyl) -butanone-1, 2-benzyl-diethylamino-1- (4-morpholinophenyl) -butanone-1,2. -Benzyl-dimethylamino-1- (4-morpholinophenyl) -propanone-1,2-benzyl-diethylamino-1- (4-morpholinophenyl) -propanone-1,2-benzyl-dimethylamino-1- ( 4-morpholinophenyl) -pentanone-1, 2-benzyl-diethylamino-1- (4-morpholinophenyl) -pentanone-1, and the like.

  The photopolymerization initiators may be used alone or in combination of two or more.

In addition, the dental curable composition of the present invention may contain pigments, fluorescent pigments, dyes, and ultraviolet absorbers to prevent discoloration to ultraviolet rays in order to match the color of the teeth. You may mix | blend a well-known additive as a component of a restoration | repair material in the range which does not affect the effect of this invention.

  In the present invention, the method for mixing the above-described components to obtain a dental curable composition is not particularly limited, and may be any known method for producing dental materials. For example, all components to be blended may be weighed under red light and mixed well until uniform. In the resulting dental curable composition, (C) the dendritic polymer is (D) a filler in order to reduce polymerization shrinkage at the time of curing and to further increase the mechanical strength of the cured product. It is preferable to mix with the radical polymerizable monomer component ((A) aromatic radical polymerizable monomer and (B) aliphatic radical polymerizable monomer) earlier. Thereby, (C) it improves from the fine dispersibility of a dendritic polymer, and also the dispersibility of a later (D) filler improves, The effect of the said this invention comes to be exhibited notably. That is, a preferable method for producing a dental curable composition obtained in the present invention is that A) an aromatic radical polymerizable monomer and (B) an aliphatic radical polymerizable monomer are in a mass ratio of 55/45. 100 parts by mass of radically polymerizable monomer component obtained by mixing at 85/15 and 5 to 50 parts by mass of (C) dendritic polymer are mixed, and then (D) 150 to 1500 parts by mass of filler. And (E) a polymerization initiator is mixed at any point in the production process. In this production method, the polymerization initiator may be blended at any point in the production process, or may be a mixing step with the radical-polymerizable monomer component of the dendritic polymer, and the radical polymerization later. The filler may be mixed with the mixture of the functional monomer component and the dendritic polymer, or may be a separate process.

  The mixing of the radical polymerizable monomer and the dendritic polymer may be performed using a normal stirring device such as a magnetic stirrer, mechanical stirrer, propeller stirrer or the like. The mixing temperature is usually 20 to 70 ° C., and the mixing time varies depending on the type of dendritic polymer, but is preferably 30 minutes to 5000 minutes, more preferably 300 minutes to 1800 minutes. The mixing of the mixture of the radically polymerizable monomer and the dendritic polymer and the filler may be performed using a known mixing device such as a dissolver, butterfly mixer, pony mixer, etc., but preferably a mixing device for mixing by planetary motion, for example, What is necessary is just to use a planetary mixer. The mixing temperature is usually 20 to 70 ° C., and the mixing time is preferably 120 to 1500 minutes, more preferably 240 to 480 minutes.

  EXAMPLES Hereinafter, the present invention will be described in more detail with reference to examples, but the present invention is not limited only to the examples shown below.

Abbreviations of compounds used in Examples and Comparative Examples are as follows.
[Aromatic radical polymerizable monomer]
D-2.6E: 2,2-bis (4- (methacryloyloxyethoxy) phenyl) propane bis-GMA: 2,2-bis (4- (2-hydroxy-3-methacryloyloxypropoxy) phenyl) propane [Aliphatic radical polymerizable monomer]
3G: triethylene glycol dimethacrylate ND: 1,9-nonanediol dimethacrylate UDMA: 1,6-bis (methacrylethyloxycarbonylamino) 2,2,4-trimethylhexane [photoinitiator]
CQ: camphorquinone [tertiary amine compound]
DMBE: p-dimethylaminobenzoic acid ethyl ester [additive]
HQME: hydroquinone monomethyl ether BHT: 2,5-di-t-butyl-p-cresol [filler]
0.4Si-Zr: spherical silica-zirconia, γ-methacryloyloxypropyltrimethoxysilane surface-treated product (average particle size: 0.4 μm)
0.08Si-Zr: Spherical silica-zirconia, γ-methacryloyloxypropyltrimethoxysilane surface-treated product (average particle size: 0.08 μm)
[Hyperbranched polymer]
HA-DMA-200:
Nissan Chemical Industries, Ltd., molecular weight by GPC method: 22000, hydrodynamic average diameter: 5.2 nm (in THF)
・ HA-DVB-500:
Nissan Chemical Industries, Ltd., molecular weight by GPC method: 48000, hydrodynamic average diameter: 11.7 nm (in THF)
-HPS-200:
Nissan Chemical Industries, Ltd., molecular weight by GPC method: 23000, hydrodynamic average diameter 7.5 nm (in THF)
・ PEI:
Poly (ethylimide), manufactured by Polysciences, mass average molecular weight by GPC method: 10,000
Tables 1 and 2 show the compositions of the dental filling and restorative materials of each Example and each Comparative Example.

In addition, the filler composition shown in Table 1 is a composition shown below.
<Filler composition>
-0.4Si-Zr70 mass parts-0.08Si-Zr30 mass parts Moreover, the following additives are contained in all the dental filling restoration materials of Table 1.
<Additives>
-CQ: 0.2 parts by mass-DMBE: 0.35
-HQME: 0.15 parts by mass-BHT: 0.02 parts by mass

Moreover, mixing of each component shown in Table 1 and Table 2 was performed by the following method. Comparative Example <Production Method 1>
First, an aromatic radical polymerizable monomer and an aliphatic radical polymerizable monomer and a dendritic polymer were mixed and stirred with a mechanical stirrer at 55 ° C. for 24 hours. Next, an additive was mixed with the obtained mixture, and the mixture was stirred for 300 minutes at 25 ° C. with a mechanical stirrer and dissolved. Thereafter, this mixture and the filler composition were mixed for 7 hours at 45 ° C. under red light using a planetary mixer, and a dental filling / restoration material having a uniform composition under visual observation was obtained.

<Production method 2>
First, an additive was added to the aromatic radical polymerizable monomer and the aliphatic radical polymerizable monomer, and the mixture was stirred and dissolved at 25 ° C. for 300 minutes with a mechanical stirrer. Thereafter, the mixture obtained was mixed with the dendritic polymer and the filler composition for 7 hours under a red light at 45 ° C. using a planetary mixer, and a dental filling restoration consisting of a uniform composition under visual observation. I got the material. Comparative Examples 5 and 7 were carried out in a mode in which only the filler composition was mixed with the aromatic radical polymerizable monomer and the aliphatic radical polymerizable monomer in which the above additives were dissolved.

Examples 1-20, Comparative Examples 1-7
About the dental filling restoration material of each Example and a comparative example, the bending strength and the polymerization shrinkage rate were measured. The results are shown in Table 2. Moreover, about the dental filling restoration material of Example 3, 4, 11-16, the coloring resistance test and the light resistance test were also measured, and the result was shown in Table 3.

  When the evaluation results were compared between Examples and Comparative Examples using the same filler composition and the same amount of dendritic polymer, the following was found. The bending strengths of Examples 1 to 22 in which the ratio of the aromatic radical polymerizable monomer to the total polymerizable monomer in the range of 55% to 85% was 95 MPa or more. On the other hand, the bending strengths of Comparative Examples 1 to 4, 6, and 7 in which the ratio of the aromatic radical polymerizable monomer to the total polymerizable monomer is not included in the range of 55% to 85% are all It was 95 MPa or less. In Comparative Example 5 in which no dendritic polymer was used, the bending strength was high, but the polymerization shrinkage ratio was larger than that in Example 4 in which the dendritic polymer was added.

  Comparing Examples 3 and 4 with Examples 17 and 18 having the same composition but different preparation methods, the filler and radical polymerizable monomer component (aromatic radical polymerizable monomer and aliphatic radical polymerization) Examples 3 and 4 in which the radical polymerizable monomer component and the dendritic polymer were mixed before mixing the radical polymerizable monomer) As compared with Examples 17 and 18 which were mixed together, the bending strength was high.

  When Examples 3, 11, 13, and 15 and Examples 4, 12, 14, and 16 in which the components other than the hyperbranched polymer are the same are compared, the dendritic polymer corresponding to the hyperbranched polymer A is added. Examples 3, 4, 11, and 12 were excellent in terms of coloring resistance and light resistance as compared with Examples 13 to 16 in which a dendritic polymer not corresponding to the hyperbranched polymer A was added. This is because the dendritic polymers added in Examples 13 to 16 have reactive unsaturated bonds and amino groups, and these structures and groups caused coloring and discoloration. Since the hyperbranched polymer A does not substantially contain these structures / groups, it is presumed that the hyperbranched polymer A exhibited good coloring resistance and light resistance.

  In addition, the measuring methods of bending strength, polymerization shrinkage ratio, coloring resistance test, and light resistance test shown in Tables 3 and 4 are as follows.

[Bending strength]
The bending strength was measured according to the following procedure. First, a dental filling / restoration material was filled in a stainless steel mold, and both surfaces of the dental filling / restoration material exposed in the openings on the front and back surfaces of the stainless steel mold were pressed with a polypropylene film. In this state, light irradiation was performed from the front and back sides using a dental light irradiator (Tokuso Power Light, manufactured by Tokuyama Dental Co., Ltd .; light output density 700 mW / cm ² ). Light irradiation was performed for 10 seconds per time on one side, and the irradiation position was changed so that the entire dental filling / restoration material was irradiated with light for a total of 5 times. Moreover, light irradiation was implemented by sticking a dental light irradiator to a polypropylene film. This obtained the hardening body. Next, after the cured body was stored overnight in water at 37 ° C., it was further polished with # 1500 water-resistant abrasive paper to obtain a prismatic test piece (2 mm × 2 mm × 25 mm). Thereafter, the sample piece was mounted on a testing machine (manufactured by Shimadzu Corporation, Autograph AG5000D), and the three-point bending fracture strength was measured at a distance between supporting points of 20 mm and a crosshead speed of 1 mm / min. And the average value of the value obtained by measuring about 5 test pieces was made into bending strength.

[Polymerization shrinkage]
Insert a SUS plunger with a diameter of less than 3 mm and a height of 4 mm into a 7 mm thick stainless steel (SUS) split mold with a 3 mm diameter through hole formed, One opening was closed and the hole depth was adjusted to 3 mm. Next, after filling the hole with a dental filling and restorative material, the upper end of the hole was pressed with a polypropylene film. Next, a dental irradiator (Tokuso Power Light, manufactured by Tokuyama Dental Corp .; light output density 700 mW / cm ² ) was provided below the center of the glass top plate of the glass table. The above-mentioned SUS split mold was placed on the top surface of the glass top plate of the glass table with the surface on which the polypropylene film was attached facing downward. Further, a short needle capable of measuring the movement of a minute needle was brought into contact with the upper surface of the SUS plunger. In this state, the dental filling / restoration material was polymerized and cured by a dental irradiator, and the shrinkage rate [%] 3 minutes after the start of irradiation was calculated from the moving distance of the short needle in the vertical direction.

[Color resistance test]
A dental filling / restoring material was filled in a 3 mm thick polyacetal mold having a through hole with a diameter of 8 mm, and then both ends of the through hole were pressed with a polypropylene film. Next, light irradiation was performed for 10 seconds with a dental light irradiator (Tokuso Power Light, manufactured by Tokuyama Dental Co., Ltd .; light output density 700 mW / cm ² ) to produce a cured body (test piece). About the obtained test piece, the surface was buffed. Thereafter, the test piece whose surface was polished was immersed in 100 ml of an aqueous coffee solution having a concentration of 7.4% by mass at 80 ° C. for 24 hours. After the immersion, the degree of coloring of the test piece washed and dried was visually observed. At this time, between samples prepared using the same matrix composition and the same filler composition, the degree of coloring was relatively evaluated using a dental filling / restoration material containing no hyperbranched polymer as a reference sample. The evaluation criteria are as follows.
A: The coloring degree of the evaluated sample is almost the same as the coloring degree of the reference sample.
B: The degree of coloring of the evaluated sample is extremely slightly lower than the degree of coloring of the reference sample.
C: The coloring degree of the evaluated sample is slightly worse than the coloring degree of the reference sample.
D: The degree of coloring of the evaluated sample is very poor compared to the degree of coloring of the reference sample (which is worse than C evaluation but better than E evaluation).
E: The coloring degree of the evaluated sample is remarkably worse than the coloring degree of the reference sample.
[Light resistance test]
After filling a dental filling / restoring material into a 1 mm thick polyacetal mold having through holes with a diameter of 15 mm, both ends of the through holes were pressed with a polypropylene film. Next, with a dental light irradiator (Tokuso Power Light, manufactured by Tokuyama Dental Co., Ltd .; light output density 700 mW / cm ² ), light is applied to the entire circular dental filling / restoration material filled in the through hole. In order to irradiate, light was irradiated for 10 seconds each at five locations in the circle (the center of the circle and the vicinity of the circle at positions every 90 degrees in the circumferential direction). This obtained the disk-shaped hardening body (test piece). Next, half of the obtained test piece was covered with aluminum foil, and exposed to simulated sunlight for 4 hours with a xenon weather meter (manufactured by Suga Test Instruments Co., Ltd., light intensity: 40 W / m ² ). Then, the color tone of the part (unexposed part) covered with the aluminum foil and the part (exposed part) exposed to simulated sunlight was visually observed. The evaluation criteria are as follows.
○: The color tone of the unexposed area and the color tone of the exposed area are almost equal or slightly different.
X: The exposed part significantly changes in color with respect to the unexposed part, and a clear difference is recognized between the two colors.

Claims (3)

(A) an aromatic radical polymerizable monomer, (B) an aliphatic radical polymerizable monomer, (C) a dendritic polymer, (D) a filler, and (E) a polymerization initiator A dental curable composition comprising:
The mass ratio of (A) aromatic radical polymerizable monomer and (B) aliphatic radical polymerizable monomer is 55/45 to 85/15,
The blending amount of the (C) dendritic polymer is 5 to 50 parts by mass with respect to 100 parts by mass of the total amount of the (A) aromatic radical polymerizable monomer and the (B) aliphatic radical polymerizable monomer. , and the and (D) the amount of the filler is Ri 150 to 1,500 parts by mass der, wherein (B) dendritic polymers, the unit structure represented by the following general formula (I), the following general formula (IIA) And a hyperbranched polymer comprising at least one unit structure selected from a unit structure represented by the following general formula (IIB):

[In the general formula (I), A is a single bond that bonds C and R ¹ ,> C═O, —O—, —COO—, or —COO—CH ₂ —, and R ¹ is It is a divalent saturated aliphatic hydrocarbon group or a divalent aromatic hydrocarbon group, and R ² is a hydrogen atom or a methyl group. In the general formula (IIA) and the general formula (IIB), R ³ , R ⁴ and R ⁵ are each a hydrogen atom, an alkyl group having 1 to 5 carbon atoms constituting the main chain, The chain is an alkoxycarbonyl group, aryl group, or cyano group having 1 to 5 carbon atoms.
In the general formula (IIB), R ⁶ is an alkylene group having 4 to 10 carbon atoms constituting the main chain. ] The dental curable composition according to claim 1, which is a tooth filling restoration material. 100 parts by mass of a radical polymerizable monomer component obtained by mixing (A) an aromatic radical polymerizable monomer and (B) an aliphatic radical polymerizable monomer at a mass ratio of 55/45 to 85/15 And (C) 5 to 50 parts by mass of the dendritic polymer, and then (D) 150 to 1500 parts by mass of the filler, and (E) polymerization at any point in the manufacturing process. The method for producing a dental curable composition according to claim 1, wherein an initiator is mixed.