JP2001151808A - Curable composition - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a curable composition for providing a cured material having a high fracture toughness value and flexural strength in use for a restorative dental material, usable instead of a metal restorative dental material in restoration of a part to which a high occlusion pressure is applied, useful as a restorative dental material capable of carrying out restoration having no color difference between the restorative dental material and natural teeth. SOLUTION: This curable composition comprises (A) a polymerizable monomer containing a polymerizable unsaturated bond-containing N-substituted amide compound of the formula, (B) an inorganic mixed filler composed of 40-99 wt.% of an approximately spherical inorganic particle having an average particle diameter in the range of >0.1 μm and <=5 μm and 60-1 wt.% of an inorganic fine particle having 0.01-0.1 μm average particle diameter or an inorganic filler obtained by compounding the inorganic mixed filler with (D) an amorphous inorganic particle which has an average particle diameter in the range of >0.1 μm and <=9 μm and comprises <=3 wt.% of particle having >=10 μm particle diameter and (C) a polymerization initiator.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

TECHNICAL FIELD The present invention relates to a curable composition suitable as a dental composite restoration material. More specifically, the present invention provides a curable composition that gives a cured product having extremely high mechanical strength, particularly, fracture toughness.

[0002]

2. Description of the Related Art Dental composite restorative materials are often used as materials for restoring treated teeth because they can impart a color tone equivalent to natural tooth color and are easy to operate. In recent years, conventional metallic materials have been used. It has also come to be used for restoring molars and the like that have been used under high occlusal pressure.

[0003] However, the restoration material has a lower mechanical strength than natural teeth, and for example, a dental restoration material was prepared from a dental restoration material such as an inlay, an onlay or a crown. In some cases, when the occlusal pressure is high, the fracture of these crown materials may occur.

[0004] That is, in the restoration of a molar part or the like to which a high occlusal pressure is applied, not only the color change before and after the restoration is small, but also the physical properties related to aesthetics such as excellent surface lubrication are excellent. A particularly high mechanical strength that can withstand the pressure is required.

Conventionally, as a dental restorative material having excellent aesthetics and strength, a photocurable dental restorative material containing a highly filled mixture of a spherical inorganic filler having a relatively large average particle diameter and a finely divided inorganic filler is used. It has been known. For example, JP-A-8-12305 discloses that 60 to 99% by weight of substantially spherical inorganic oxide particles having an average particle diameter of more than 0.1 μm and 1 μm or less, and an average particle diameter of 0.1 to 0.1 μm.
40 to 1% by weight of inorganic oxide fine particles in the range of μm or less
A composite material with a photo-curable dental restoration that uses a high-dispersion mixture of dentistry and other materials provides mechanical strength, surface lubricity, and a property that does not abrade the teeth that mesh with the restored tooth ) Is described.

Certainly, the above-mentioned photo-curable dental composite restoration material is excellent in both aesthetics and strength, and can be said to have sufficient physical properties, for example, for restoration of anterior teeth. However, when the photocurable composite restoration material is used for restoring a molar part or the like to which a high occlusal pressure is applied, its mechanical strength is not always satisfactory. For example, the bending strength of the cured product shows a high value of 200 MPa or more, but the fracture toughness value (K _IC ), which is an important physical property value related to the fracture of the repair material, is 2.3 MPa · m ^1/2 , It was not a satisfactory value for restoring molars.

[0007]

DISCLOSURE OF THE INVENTION The present invention provides a curable composition which provides a cured product having high mechanical strength, particularly high fracture toughness, which could not be achieved with a conventional composite composite restoration material. It provides things.

[0008]

Means for Solving the Problems The inventors of the present invention have made intensive studies to overcome the above-mentioned problems, and have found that a specific polymerizable unsaturated bond-containing N-substituted amide compound is used as a polymerizable monomer. As a result, it has been found that the above object can be achieved, and the present invention has been completed. That is, the present invention
[A] The following general formula (1)

[0009]

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[Wherein, R ¹ is an organic group comprising a carbon atom, a hydrogen atom, a nitrogen atom or an oxygen atom, and is at least one selected from the group consisting of a benzene ring, a naphthalene ring and an anthracene ring. Is an organic group having 1 to 3 carbon atoms having 1 to 3 aromatic rings having 6 to 24 carbon atoms, and R ² is
The following general formula

[0011]

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In the formula, A ¹ and A ² are each independently an oxygen atom or —NH—, and B ¹ and B ² are each independently a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, Number 1
5 to 5 alkoxy groups or phenyl groups, and R ⁴ is
A hydrocarbon group having 1 to 12 carbon atoms, r ₁ , r ₂ , and r
₃ is any group represented by｝, each independently being an integer of 1 to 5, R ³ is a hydrogen atom or a methyl group, and n is an integer of 1 to 3. A) a polymerizable monomer containing a polymerizable unsaturated bond-containing N-substituted amide compound represented by the formula: [B] 40 to 99 weight of substantially spherical inorganic particles having an average particle size of more than 0.1 µm and 5 µm or less. % And the average particle diameter is 0.01 to 0.1 μm.
It is a curable composition containing an inorganic mixed filler consisting of 1% by weight and [C] a polymerization initiator.

[0013]

DETAILED DESCRIPTION OF THE INVENTION The curable composition of the present invention comprises a polymerizable monomer, a filler and a polymerization initiator. The polymerizable monomer has an amide bond and a (meth) acryl group or a (meth) acrylamide group in its molecular structure, and has at least one member selected from the group consisting of a benzene ring, a naphthalene ring, and an anthracene ring. It is essential to contain a polymerizable unsaturated bond-containing N-substituted amide compound represented by the general formula (1) having an aromatic ring of the formula (1).

In the above general formula (1), R ¹ is a C 6-24 alkyl having at least one aromatic ring selected from the group consisting of a benzene ring, a naphthalene ring and an anthracene ring. It is a trivalent organic group and may contain a nitrogen atom and an oxygen atom.

The structure of R ¹ is not particularly limited as long as it satisfies the above conditions.

[0016]

Embedded image A group represented by is exemplified.

In the above formula, R ⁵ , R ⁶ , R ⁷ and R ⁸
Is independently a hydrogen atom, an alkyl group having 1 to 10 carbon atoms, or an alkoxy group having 1 to 10 carbon atoms.
When ^{R 5, R 6, R 7} , and R ⁸ is an alkyl group having 1 to 10 carbon atoms, if illustrating preferred specific examples of the alkyl group include a methyl group, an ethyl group, n- propyl group, and is
o-propyl group and the like. Also, R ⁵ , R ⁶ ,
When R ⁷ and R ⁸ are an alkoxy group having 1 to 10 carbon atoms, preferred specific examples of the alkoxy group include a methoxy group, an ethoxy group, an n-propoxy group, and an iso-propoxy group.

The alkyl group and the alkoxy group represented by R ⁵ , R ⁶ , R ⁷ , and R ⁸ are each independently selected from the group consisting of 1 to 10 carbon atoms. When the total number of carbon atoms of the group substituted on the aromatic ring exceeds 15, the refractive index and the strength of the cured product may be reduced. Therefore, R ⁵ , R ⁶ , R ⁷ , and R ⁸ are the carbon atoms. It is preferred that the sum of the numbers be selected from a range not exceeding 15.

In the present invention, a particularly preferable structure of R ¹ has a large effect of improving strength.

[0020]

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The groups represented by Further, R ¹ is represented by the following formula because it is easily available and can form a crosslinked structure after curing.

[0022]

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Most preferably, the group is represented by In the general formula (1), R ² is a group represented by the following general formula.

[0024]

Embedded image In the above formula, A ¹ and A ² are each independently an oxygen atom or —NH—.

Also, B¹And B^TwoIs independently hydrogen
Atom, alkyl group having 1 to 5 carbon atoms, alkyl group having 1 to 5 carbon atoms
It is a xy group or a phenyl group. B¹And B^TwoIs the carbon number
When it is 1 to 5 alkyl groups, a suitable
Specific examples include a methyl group, an ethyl group, and n-propyl.
And an iso-propyl group. Also, B ¹
And B^TwoIs an alkoxy group having 1 to 5 carbon atoms,
A preferred specific example of the alkoxy group is methoxy.
Group, ethoxy group, n-propoxy group, and iso-propoxy group
And the like.

R ⁴ is a hydrocarbon group having 1 to 12 carbon atoms. When R ⁴ is an alkyl group or an alkenyl group, if the total number of carbon atoms exceeds 10, the refractive index may decrease. Therefore, it is preferable that the total number be selected from a range not exceeding 10. Further, r1, r2, and r
3 is each independently an integer of 1 to 5; r1, r2
And r3 are not particularly limited as long as the above conditions are satisfied. However, if the total number of r1, r2, and r3 in each group represented by the above formula exceeds 10, the refractive index and the strength of the cured product may be reduced. And preferably not more than 10.

Note that r1 and r3 are integers of 2 to 5.
In this case, a plurality of-(B¹CB^Two) -Unit and-
｛(CH_Two) R2A^Two｝-Unit will be connected
However, at this time, the group (B¹, B^Two, R2 and
A^Two) May be different. Also, in the formula
In any of the groups, the bond at the right end is -COCH = C
H _TwoOr —COC (CH_Three) = CH_TwoCombine with

In the present invention, R ₂ is preferable because it has a large effect of improving the strength of the cured product.

[0029]

Embedded image The group shown by these is mentioned.

Among these groups, R ² is represented by the following formula because of ease of synthesis.

[0031]

Embedded image The group represented by is most preferred.

In the general formula (1), n is an integer of 1 to 3, and a particularly preferable number of n is 2 or 3 which can form a crosslinked structure after curing. Also, n
Is 2 or 3, there are a plurality of units enclosed in square brackets ([]) bonded to R ¹ , but the combination of R ² in each unit may be different.

Particularly preferred examples of the N-substituted amide compound having a polymerizable unsaturated bond of the present invention are as follows.

[0034]

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[0035]

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In the curable composition of the present invention, other polymerizable monomers may be added in order to further improve the physical properties and adjust the viscosity.

The other polymerizable monomers are not particularly limited, and known polymerizable monomers that can be generally used in dental restorative materials can be used without any limitation. Examples of other polymerizable monomers that can be suitably used include a polymerizable monomer having a (meth) acryloyl group. Specific examples of such a polymerizable monomer include the following a) to d) Each monomer shown in the above is mentioned. A) Monofunctional vinyl monomers Methacrylates such as methyl methacrylate, ethyl methacrylate, isopropyl methacrylate, hydroxyethyl methacrylate, tetrahydrofurfuryl methacrylate, glycidyl methacrylate, and acrylates corresponding to these methacrylates; or acrylic acid, methacrylic acid, p-methacryloyl Oxybenzoic acid, N-2-hydroxy-3-methacryloyloxypropyl-N-phenylglycine, 4-methacryloyloxyethyl trimellitic acid, and anhydrides thereof, 6-methacryloyloxyhexamethylenemalonic acid, 10-methacryloyloxydecamethylene Malonic acid, 2-methacryloyloxyethyl dihydrogen phosphate, 10-methacryloyloxydecamethylene Dihydrogen phosphate, 2-hydroxyethyl hydrogen phenyl phosphonate, etc. b) Bifunctional vinyl monomer (I) Aromatic compound type 2,2-bis (methacryloyloxyphenyl) propane, 2,2-bis [4- (3-methacryloyloxy)
-2-hydroxypropoxyphenyl] propane (hereinafter abbreviated as bis-GMA), 2,2-bis (4-
(Methacryloyloxyphenyl) propane, 2,2-bis (4-methacryloyloxypolyethoxyphenyl)
Propane (hereinafter abbreviated as D-26E), 2,2-bis (4-methacryloyloxydiethoxyphenyl) propane, 2,2-bis (4-methacryloyloxytetraethoxyphenyl) propane, 2,2-bis (4-
Methacryloyloxypentaethoxyphenyl) propane, 2,2-bis (4-methacryloyloxydipropoxyphenyl) propane, 2 (4-methacryloyloxydiethoxyphenyl) -2 (4-methacryloyloxydiethoxyphenyl) propane, 2 (4 -Methacryloyloxydiethoxyphenyl) -2 (4-methacryloyloxyditriethoxyphenyl) propane, 2 (4
-Methacryloyloxydipropoxyphenyl) -2-
(4-methacryloyloxytriethoxyphenyl) propane, 2,2-bis (4-methacryloyloxypropoxyphenyl) propane, 2,2-bis (4-methacryloyloxyisopropoxyphenyl) propane and acrylates corresponding to these methacrylates; 2
Methacrylates such as hydroxyethyl methacrylate, 2-hydroxypropyl methacrylate, 3-chloro-2-hydroxypropyl methacrylate or acrylates corresponding to these methacrylates;
Diadducts and the like obtained by addition of a vinyl monomer having an OH group and a diisocyanate compound having an aromatic group such as diisocyanate methylbenzene and 4,4'-diphenylmethane diisocyanate. (II) Aliphatic compound type ethylene glycol dimethacrylate , Diethylene glycol dimethacrylate, triethylene glycol dimethacrylate (hereinafter abbreviated as 3G), butylene glycol dimethacrylate, neopentyl glycol dimethacrylate, propylene glycol dimethacrylate, 1,3-butanediol dimethacrylate, 1,4
-Butanediol dimethacrylate, 1,6-hexanediol dimethacrylate and acrylates corresponding to these methacrylates; 2-hydroxyethyl methacrylate, 2-hydroxypropyl methacrylate,
A vinyl monomer having an -OH group such as methacrylate such as 3-chloro-2-hydroxypropyl methacrylate or an acrylate corresponding to these methacrylates; hexamethylene diisocyanate, trimethylhexamethylene diisocyanate, diisocyanate methyl cyclohexane, isophorone diisocyanate, and methylene bis. Diadduct obtained from addition with a diisocyanate compound such as (4-cyclohexyl isocyanate); acrylic acid anhydride, methacrylic anhydride;
1,2-bis (3-methacryloyloxy-2-hydroxypropoxy) ethyl, di (2-methacryloyloxypropyl) phosphate, etc. c) Trifunctional vinyl monomer trimethylolpropane trimethacrylate, trimethylolethane trimethacrylate, pentaerythritol Methacrylates such as trimethacrylate and trimethylolmethane trimethacrylate and acrylates corresponding to these methacrylates, etc. d) Tetrafunctional vinyl monomers pentaerythritol tetramethacrylate, pentaerythritol tetraacrylate and diisocyanatomethylbenzene, diisocyanatomethylcyclohexane, isophorone diisocyanate, hexa Methylene diisocyanate, trimethylhexamethylene diisocyanate G, methylene bis (4-cyclohexyl isocyanate), 4,4-diphenylmethane diisocyanate,
These polymerizable monomers such as diadduct obtained from addition of a diisocyanate compound such as tolylene-2,4-diisocyanate and glycidol dimethacrylate are:
It may be used alone, but may be used by adding two or more kinds. The compounding amount of the above polymerizable monomer may be selected according to the purpose, but 0 to 100 parts by weight of the polymerizable unsaturated bond-containing N-substituted amide compound of the present invention.
It is preferably used in the range of 9900 parts by weight,
It is particularly preferred to use it in the range of 1000 parts by weight.

As the filler used in the curable composition of the present invention, substantially spherical inorganic particles having an average particle diameter in the range of more than 0.1 μm and 5 μm or less (hereinafter referred to as “spherical particles a”)
In addition, it is essential to use an inorganic mixed filler composed of inorganic fine particles having an average particle diameter of 0.01 to 0.1 μm (hereinafter referred to as fine particles b).

As the spherical particles a, known inorganic particles can be used without particular limitation as long as they are substantially spherical inorganic particles having an average particle diameter of more than 0.1 and 5 μm or less. Here, a substantially spherical shape means
A photograph of the filler is taken with a scanning electron microscope (hereinafter abbreviated as SEM), and the particles observed in the unit field of view are rounded, and the particle diameter in a direction orthogonal to the maximum diameter is divided by the maximum diameter. The average degree of symmetry obtained is 0.6 or more. When the average particle diameter of the spherical particles a is 0.1 μm or less, when used as a dental restorative material, the filling rate of the inorganic filler is reduced and the mechanical strength is low. Also, 5μ
When it is larger than m, the surface area of the substantially spherical inorganic particles per unit volume of the curable composition decreases, and a cured product having high mechanical strength cannot be obtained. Further, when the shape is not substantially spherical, it becomes difficult to increase the filling amount to a target range, and a cured product having high mechanical strength cannot be obtained. The material (component) of the spherical particles a is not particularly limited as long as the above conditions are satisfied.
It is generally an inorganic oxide such as amorphous silica, silica zirconia, silica titania, silica titania barium oxide, quartz, and alumina. As these inorganic oxides, a small amount of a metal oxide of Group I of the periodic table was present in the inorganic oxide for the purpose of easily obtaining the dense inorganic oxide when firing at a high temperature. A composite oxide can also be used. As the material of the spherical particles a, having a X-ray contrast property, a cured body having more excellent wear resistance is obtained,
A composite oxide containing silica and zirconia as main components is particularly preferably used. The spherical particles a do not necessarily have to be a single filler as long as the average particle diameter is within the above range. For example, as shown in JP-B-3-10603, the average particle diameter and the material (component) are not limited. It may be a mixture of different fillers. The particle size distribution of the spherical particles a is not particularly limited, but the operation of the curable composition of the present invention is performed when the particle diameter variation coefficient is excellent in monodispersity such that it is within 0.3. The property becomes good. The method for producing the spherical particles a is not particularly limited, but is generally produced industrially by hydrolysis of a metal alkoxide. In order to maintain the surface stability of the spherical particles a, it is preferable to reduce the number of silanol groups on the surface. For this purpose, a means of baking at a temperature of 500 to 1000 ° C. is often suitably used. Fine particles b used in the present invention
Is not particularly limited as long as the inorganic fine particles have an average particle diameter in the range of 0.01 to 0.1 μm. The shape of the fine particles b is not particularly limited, and may have any shape such as a substantially spherical shape, a needle shape, a plate shape, and an irregular shape. However, from the viewpoint of the strength and surface lubricity of the cured product, it is preferable to use substantially spherical particles. The material (component) is not particularly limited, and a material similar to that of the spherical particles a can be used without limitation. The fine particles b do not necessarily need to be composed of a single filler as long as the average particle diameter is within the above range. Two or more mixed fillers having different average particle diameters and different materials (components) are used. There may be. Specific examples of the fine particles b generally preferably used include, for example, ultrafine silica, ultrafine alumina, ultrafine zirconia, ultrafine titania, amorphous silica, silica zirconia, silica titania, Silica titania is an inorganic oxide such as barium oxide, quartz, and alumina. Further, a composite oxide in which a small amount of an oxide of a metal of Group I of the periodic table is present in the inorganic oxide for the purpose of easily obtaining a dense one when the above inorganic oxide is fired at a high temperature. Can also be used.

In the inorganic mixed filler comprising the spherical particles a and the fine particles b according to the present invention, the volume of strongly agglomerated pores having a pore diameter of 0.08 μm or more is 0.1 (cc / g-filler) or less. It is preferable because the mechanical strength of the obtained cured product is particularly high. The method for evaluating the “volume of the strongly aggregated pores having a pore diameter of 0.08 μm or more” will be described later.

In the curable composition of the present invention, for the purpose of further improving the strength of the cured product, [D] the average particle size is more than 0.1 μm and not more than 9 μm and not less than 10 μm. It is preferable to mix irregularly shaped inorganic particles containing 3% by weight or less of particles (hereinafter referred to as irregularly shaped particles c). At this time, by adding [D] amorphous inorganic particles in an amount of 10 to 300 parts by weight to 100 parts by weight of the inorganic mixed filler (B), the mechanical strength of the dental restoration material is increased. It is possible to further improve significantly.

When the inorganic filler is made of the above [D] amorphous inorganic particles having relatively large average particle diameter of 2 to 9 μm, the filling rate of the inorganic filler is particularly high. Therefore, since the thermal expansion coefficient is reduced, the durability of a dental restoration material can be significantly improved. On the other hand, among the above [D] amorphous inorganic particles, the average particle diameter is particularly more than 0.1 μm and 1 μm.
m or less, the use of inorganic filler in which amorphous inorganic particles having a relatively small particle size are blended in an amount of 10 to 300 parts by weight, the effect of improving the filling rate is not so large, Thus, a dental restorative material having very excellent mechanical strength can be obtained without lowering aesthetics such as properties. The material (component) of the irregular-shaped particles c is not particularly limited as long as the above-mentioned conditions are satisfied, but an inorganic substance insoluble in water is used without any particular limitation.
Specifically, borosilicate glass, soda glass, glass containing heavy metals (for example, barium, strontium, and zirconium), aluminosilicate, fluoroaluminosilicate, glass ceramics, silica, and composite inorganic materials such as silica zirconia, silica titania, and silica alumina Oxides and the like are preferred. The mixing ratio of the inorganic particles used in the present invention is as follows. [B] The mixing ratio of the spherical particles a and the fine particles b in the inorganic mixed filler is such that when the total amount of these is 100% by weight, the spherical particles a are 40 to 99% by weight, preferably 6% by weight.
0 to 90% by weight, the fine particles b are 60 to 1% by weight,
Preferably it is 40 to 10% by weight. When the spherical particles a are smaller than 40% (the fine particles b are larger than 60% by weight) in the above blending amount, the mechanical strength of the cured product after polymerization and curing is reduced. Conversely, the spherical particles a
If it is larger than the weight%, the mechanical strength is reduced. Next, in the inorganic filler composed of [B] the inorganic mixed filler and [D] the amorphous inorganic particles, the blending amount of the irregular particles c is 300 parts by weight when the total amount of the spherical particles a and the fine particles b is 100 parts by weight. Parts by weight, preferably up to 230 parts by weight. When the weight part of the irregular-shaped particles c is larger than 300, even if the total amount of the spherical particles a and the fine particles b satisfies the above range, the particles have higher mechanical strength and sufficient aesthetics. A cured product cannot be obtained.

In the curable composition of the present invention, it is preferable that the surfaces of the spherical particles a, the fine particles b and the irregular particles c are made hydrophobic for the purpose of improving the dispersibility in the polymerizable monomer. . Such a hydrophobizing treatment is not particularly limited, and a known method is adopted without any limitation. If a typical hydrophobic treatment method is exemplified, a silane coupling agent as a hydrophobizing agent, for example, a treatment with an organosilicon compound such as γ-methacryloyloxyalkyltrimethoxysilane, hexamethyldisilazane, or a titanate-based coupling agent There is a method of using the method and a method of graft-polymerizing the polymerizable monomer on the particle surface. Such processing is performed by using spherical particles a,
It may be performed after mixing the fine particles b and the irregular-shaped particles c, or may be performed in advance for each particle. The total amount of the inorganic particles in the curable composition of the present invention is preferably from 300 to 1900 parts by weight, more preferably from 500 to 120 parts by weight, based on 100 parts by weight of the polymerizable monomer.
0 parts by weight. When the amount of the inorganic filler is less than 300 parts by weight, it is difficult to obtain a cured body as a dental restoration material having high mechanical strength due to an insufficient filling rate. On the other hand, when the amount is more than 1900 parts by weight, the inorganic filler cannot be uniformly dispersed in the polymerizable monomer, resulting in a dental restoration material having low mechanical strength. Incidentally, the inorganic particles in the present invention, [B] the inorganic mixed filler is essential, and if necessary, (D) contains amorphous inorganic particles,
Further, a small amount of other inorganic particles may be contained within a range not to impair the object of the present invention.

In the above-mentioned inorganic filler, it is preferable that the dispersibility of the constituent particles spherical particles a, fine particles b and irregular-shaped particles c is high from the viewpoint of the strength of the obtained cured product. Regarding such dispersibility, see JP-A-8-12.
As described in JP-A-305, it can be evaluated by the volume of strongly aggregated pores having a pore diameter of 0.08 μm or more in the inorganic filler. Here, the pore diameter and the volume of the strongly aggregated pores can be measured by the mercury intrusion method, and the pore diameter is determined from the pore distribution determined by the pore volume measurement at the time of pressurization. The volume is a value determined based on a pore volume curve measured at the time of decompression and taking into account a shift in the pore diameter at the time of measurement at the time of pressure reduction and at the time of measurement at the time of pressure application.

In the case of the inorganic filler, the pore size is preferably 0.
The volume of strongly coagulated pores of not less than 08 µm is 0.1 (cc / g-
Filler) or less, the resulting cured product has particularly high mechanical strength, and it is preferable to use an inorganic filler in such a dispersed state. Such dispersion can be realized, for example, by dispersing the inorganic filler in a medium such as pure water at a high processing pressure such as 60 MPa using an ultrahigh pressure impact type emulsifying and dispersing machine Nanomizer. As the polymerization initiator [C] used in the curable composition of the present invention, a known polymerization initiator is used without any particular limitation. Generally, different types of polymerization initiators are used depending on the means of polymerizing the polymerizable monomer. Examples of the polymerization means include a method using light energy such as ultraviolet rays and visible light, a method using a reaction between a peroxide and an accelerator, and a method using heating. The polymerization means can be selected as needed. For example, as a polymerization initiator by a reaction by light energy (hereinafter, referred to as photopolymerization), benzoin alkyl ethers such as benzoin methyl ether, benzoin ethyl ether, and benzoin isopropyl ether; and benzyl ketals such as benzyl dimethyl ketal and benzyl diethyl ketal. Benzophenones such as benzophenone, 4,4'-dimethylbenzophenone, 4-methacryloxybenzophenone, diacetyl, 2,3-pentadionebenzyl, camphorquinone, 9,10-phenanthraquinone, and 9,10-anthraquinone; thioxanthone compounds such as α-diketones, 2,4-diethoxythioxanthone, 2-chlorothioxanthone and methylthioxanthone; bis- (2,6-dichlorobenzoyl) phenylphosphine Benzoate, bis- (2,6-dichlorobenzoyl) -2,5-dimethylphenylphosphine oxide, bis- (2,6-dichlorobenzoyl) -4
-Propylphenylphosphine oxide, bis-
Examples include bisacylphosphine oxides such as (2,6-dichlorobenzoyl) -1-naphthylphosphine oxide and bis (2,4,6-trimethylbenzoyl) -phenylphosphine oxide. A reducing agent is often added as one component of the photopolymerization initiator, and examples thereof include tertiary amines such as 2- (dimethylamino) ethyl methacrylate, ethyl 4-dimethylaminobenzoate, and N-methyldiethanolamine. Aldehydes such as lauraldehyde, dimethylaminobenzaldehyde, terephthalaldehyde, 2-mercaptobenzoxazole, 1-decanethiol, thiosalicylic acid,
Examples thereof include sulfur-containing compounds such as thiobenzoic acid. As a polymerization initiator in thermal polymerization, for example,
Peroxides such as benzoyl peroxide, p-chlorobenzoyl peroxide, tert-butylperoxy-2-ethylhexanoate, tert-butylperoxydicarbonate, diisopropylperoxydicarbonate, azobisisobutyronitrile, etc. Azo compound, tributylborane, tributylborane partial oxide,
Boron compounds such as sodium tetraphenylborate, sodium tetrakis (p-fluorophenyl) borate, and triethanolamine tetraphenylborate;
Examples include barbituric acids such as butyl barbituric acid and 1-benzyl-5-phenyl barbituric acid, and sulfinic acid salts such as sodium benzenesulfinate and sodium p-toluenesulfinate. Among these polymerization initiators, a photopolymerization initiator is generally used for reasons of simplicity of operation. Specific examples of particularly suitable photopolymerization initiators include camphorquinone and bis (2,4,6).
-Trimethylbenzoyl) -phenylphosphine oxide and bis (2,6-dimethoxybenzoyl)-
2,4,4-trimethylphenylphosphine oxide is exemplified.

The above-mentioned polymerization initiators may be used alone or in combination of two or more. The amount of the polymerization initiator to be added may be selected according to the purpose, but generally, based on 100 parts by weight of the total polymerizable monomer including the polymerizable unsaturated bond-containing N-substituted amide compound of the present invention, 0.0
It is used in an amount of 1 to 30 parts by weight, more preferably 0.1 to 5 parts by weight.

The curable composition of the present invention may contain known additives as long as the effect is not significantly impaired. Examples of such additives include a polymerization inhibitor, a pigment, and an ultraviolet absorber.

As the method for curing the curable composition of the present invention, an optimum method may be selected according to the type of the polymerization initiator. For example,
When a polymerization initiator for photopolymerization is used, it is generally preferable to irradiate light for 10 seconds or more, preferably for 30 seconds to 1 hour, and then at a temperature of 80 to 120 ° C.
Heating for minutes to 20 hours is preferable to obtain a cured product having high mechanical strength. Further, when a polymerization initiator for thermal polymerization is used, the temperature is 60 to 200 ° C., particularly 80 ° C.
A method of heating at a temperature of １２０120 ° C. for 10 minutes to 20 hours, particularly 15 minutes to 1 hour is preferred. In this case, the polymerization is preferably performed under an atmosphere of an inert gas such as nitrogen or helium, or steam. When the curable composition of the present invention is used as a dental restorative material, generally, a predetermined amount of each of the above-mentioned essential components and each of the optional components is used, and these components are mixed and vacuum-defoamed, once in the form of a paste. After being used as a dental restorative material, it is shaped into a tooth and then hardened for use.

The general molding and curing methods include:
(1) A method of filling directly into the cavity of the tooth to be restored, forming it into a tooth shape, and then irradiating it with strong light with a special light irradiator to polymerize and cure, (2) On the abutment model outside the oral cavity Alternatively, a method of restoring a tooth by building up on a metal frame, forming into a tooth shape, polymerizing and curing, and then mounting it in the oral cavity using a dental adhesive or the like may be used.

[0050]

According to the curable composition of the present invention, a cured product having high mechanical strength, particularly high fracture toughness, can be obtained. Therefore, in the use of dental restorative materials, metal restoration materials such as inlay restoration and crown restoration have been used in areas where high occlusal pressure is conventionally applied, but it is now possible to use these metal restoration materials instead. Therefore, restoration without a color difference with natural teeth becomes possible.

[0051]

The present invention will be described below in more detail with reference to examples, but the present invention is not limited to these examples.

The polymerizable unsaturated bond-containing N-substituted amide compound, other polymerizable monomers, photopolymerization initiator, and inorganic particles of the present invention used in Examples and Comparative Examples are as follows. is there.

(A) Polymerizable monomers N-substituted amide compounds containing polymerizable unsaturated bonds shown below (2) to (16)

[0054]

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[0055]

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2,2-bis [(3-methacryloyloxy-2-hydroxypropyloxy) phenyl] propane (hereinafter abbreviated as bis-GMA) triethylene glycol dimethacrylate (hereinafter abbreviated as 3G) (b) Polymerization initiator Bis (2,4,6-trimethylbenzoyl) -phenylphosphine oxide (hereinafter abbreviated as BTPO) (c) Inorganic particles Spherical silica-zirconia; average particle size; 0.52 μm (hereinafter abbreviated as F-1) Spherical silica-titania Average particle size: 0.08 μm (hereinafter abbreviated as F-2) amorphous silica-zirconia; average particle size: 3.4 μm, 1.0% by weight of particles having a particle size of 10 μm or more (hereinafter abbreviated as F-3) Amorphous silica-zirconia; average particle size: 0.9 μm, particles having a particle size of 10 μm or more are 1.0% by weight (hereinafter abbreviated as F-4). Aggregated pore volume shown in Comparative Examples, preparation of paste of polymerizable monomer composition, curing method, measurement of cured body mechanical strength after curing, and measurement of surface smoothness,
The following method was followed.

(1) Agglomerated pore volume A sufficiently dried filler (about 0.2 g) was weighed and measured with a mercury porosimetry pore size distribution measuring apparatus (Carlo Elva, Porosimeter 2000) under pressure and pressure reduction. The pore size and pore distribution were measured. From these results, it can be seen from JP-A-8-123.
According to the method described in Japanese Patent Publication No. 05-2005, the volume of strongly aggregated pores having a pore diameter of 0.08 μm or more (hereinafter simply referred to as aggregated pore volume) was determined.

(2) Preparation and curing method of paste of polymerizable monomer composition A predetermined amount of 3G was added to the polymerizable unsaturated bond-containing N-substituted amide compound to obtain a polymerizable monomer. A predetermined ratio of a photopolymerization initiator to the polymerizable monomer was added to prepare a polymerizable monomer composition. Next, the polymerizable monomer composition and the inorganic filler were put in an agate mortar and kneaded sufficiently in a dark place to obtain a uniform curable paste.

The above-mentioned curable paste was filled in a mold corresponding to the respective measurements shown below, cured sufficiently by irradiating light, taken out of the mold, and thermally polymerized at 100 ° C. for 20 minutes. . Then, it was immersed in water at 37 ° C. for 24 hours and used as a sample piece.

(3) A prism-shaped sample piece having a bending strength of 2 × 2 × 25 mm was mounted on a tester (Autograph 5000D, manufactured by Shimadzu Corporation), and the distance between fulcrums was 2
The three-point bending strength was measured at 0 mm and a crosshead speed of 0.5 mm / min.

(4) Fracture Toughness A prismatic sample piece of width 2 × height 4 × length 20 mm was prepared.
A crack of about 2 mm was made in the height direction with a cutter to produce a three-point bent sample piece with a notch on one side. This sample piece was mounted on a tester (Autograph 500D, manufactured by Shimadzu Corporation), the distance between fulcrums was 16 mm, and the crosshead speed was 1.0 mm
Per minute, a three-point bending test was performed, and a fracture toughness value was calculated from the fracture strength.

(5) Surface Lubricity A prismatic sample piece of width 2 × height 4 × length 20 mm was prepared.
After polishing the surface of the cured product with water resistant abrasive paper No. 1500, Sof-lex
Finish polishing was performed by Superfine (manufactured by 3M), and the glossiness of the surface was visually determined. A sample having excellent lubricity was evaluated as ○, a sample having excellent lubricity was evaluated as ◎, and a sample having poor lubricity was evaluated as ×. Example 1 N-substituted amide compound containing a polymerizable unsaturated bond (2) (6
0 parts by weight) and the diluent monomer 3G (40 parts by weight) to obtain a polymerizable monomer. BTPO (0.5 parts by weight) was added thereto to obtain a uniform polymerizable monomer composition. On the other hand, the inorganic particles F-1 (240 parts by weight) and F-2 (16
0 parts by weight) in pure water with an ultra-high pressure impact type emulsifying and dispersing machine (Nanomizer NM-LA31 manufactured by Tokushu Kika Kogyo Co., Ltd.) at a processing pressure of 60 MPa, and then dispersing the surface using γ-methacryloxypropyltrimethoxysilane. Processing was performed. After the solvent was distilled off, the residue was dried to obtain an inorganic filler. The polymerizable monomer composition and the inorganic filler were placed in an agate mortar and kneaded sufficiently in a dark place to obtain a uniform curable paste. The composition ratio is shown in Table 1. However, the meaning of each item in the table is as follows. Filler composition:% by weight of each particle when total filler weight is 100 Polymerizable monomer composition:% by weight of each polymerizable monomer when total weight of polymerizable monomer is 100 Photopolymerization Initiator:% by weight of added photopolymerization initiator based on 100 parts by weight of total polymerizable monomer composition Filler part by weight: Filler based on 100 parts by weight of total polymerizable monomer Parts by weight

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[Table 1]

The obtained curable paste was filled into a mold corresponding to each measurement, cured sufficiently by irradiating light, taken out of the mold, and further polymerized at 100 ° C. for 20 minutes. Then, it was immersed in water at 37 ° C. for 24 hours and used as a sample piece. Table 2 shows the results of the aggregated pore volume, bending strength, fracture toughness and surface lubricity.

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[Table 2]

Examples 2 to 15 The same filler composition and polymerization initiator composition as in Example 1 were used, and instead of the polymerizable unsaturated bond-containing N-substituted amide compound (2), a polymerizable unsaturated bond-containing N-substituted amide compound was used. (3)
Example 1 was prepared by preparing a curable paste by using (16) to (16).
After curing in the same manner as described above, each physical property was measured. The results are shown in Table 2.

Example 16 Using the same polymerizable monomer and photopolymerization initiator as in Example 12, the filler composition was changed to spherical particles F- as shown in Table 1.
1. A curable paste was prepared by changing to an inorganic mixed filler composed of irregular particles F-3 having an average particle diameter of 3.4 μm and fine particles F-2, and then cured in the same manner as in Example 1. Each physical property was measured. The results are shown in Table 2.

Example 17 A curable paste was prepared using the same polymerizable monomer and photopolymerization initiator as in Example 14, and the same filler composition as in Example 16, and cured in the same manner as in Example 1. After that, each physical property was measured. The results are shown in Table 2.

Example 18 Using the same polymerizable monomer and photopolymerization initiator as in Example 12, the filler composition was changed to spherical particles F- as shown in Table 1.
1. A curable paste was prepared by changing to an inorganic mixed filler composed of the fine particles F-2 and the amorphous particles F-4 having an average particle diameter of 0.9 μm, and then cured in the same manner as in Example 1. Each physical property was measured. The results are shown in Table 2.

Example 19 A curable paste was prepared using the same polymerizable monomer and photopolymerization initiator as in Example 14, and the same filler composition as in Example 18, and cured in the same manner as in Example 1. After that, each physical property was measured. The results are shown in Table 2.

Comparative Example 1 With the same filler composition and polymerization initiator composition as in Example 1,
A curable paste was prepared using bis-GMA instead of the polymerizable unsaturated bond-containing N-substituted amide compound (2), and cured in the same manner as in Example 1, and then each physical property was measured.
The results are shown in Table 2. Comparative Example 1 had a particularly low fracture toughness value as compared with Examples 1 to 15.

Comparative Example 2 A curable paste was prepared by using bis-GMA instead of the polymerizable unsaturated bond-containing N-substituted amide compound with the same filler composition and polymerization initiator composition as in Examples 16 and 17,
After curing in the same manner as in Example 1, each physical property was measured. The results are shown in Table 2. Comparative Example 2 was inferior in fracture toughness as compared with Examples 16 and 17.

Comparative Example 3 A curable paste was prepared using the same filler composition and polymerization initiator composition as in Examples 18 and 19, but using bis-GMA instead of the polymerizable unsaturated bond-containing N-substituted amide compound.
After curing in the same manner as in Example 1, each physical property was measured. The results are shown in Table 2. Comparative Example 3 was inferior in fracture toughness value as compared with Examples 17 and 19.

 ──────────────────────────────────────────────────続 き Continued on the front page F-term (reference) 4C089 AA06 BA04 BA05 BA06 BA13 BA14 BD05 4J011 PA07 PA13 PB06 PB22 PC02 PC08 4J027 AD02 BA06 BA07 BA09 BA13 BA16 BA19 BA20 BA21 BA24 BA25 BA26 BA27 CA14 CA18 CA19 CA33 CB10 CC08 CD07 4J027 AL66P AL67P AM21P AM23P BA02P BA04P BA05P BA06P BA12P BA15P BA28P BA34P BC04P BC43P BC44P BC45P BC48P BC49P CA01 CA04 FA03 JA52

Claims (5)

[Claims] [A] The following general formula (1): [In the formula, R ¹ is a C1-C3 trivalent organic group having 1 to 3 at least one aromatic ring selected from the group consisting of a benzene ring, a naphthalene ring, and an anthracene ring. R ² is represented by the following general formula: In the formula, A ¹ and A ² are each independently an oxygen atom or —NH—, and B ¹ and B ² are each independently a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, 5 is an alkoxy group or a phenyl group, and R ⁴ has 1 to 1 carbon atoms.
R ₁ , r ₂ , and r ₃ are each independently any group represented by｝, which is an integer of 1 to 5, and R ³ is a hydrogen atom or methyl And n is
It is an integer of 1 to 3. A) a polymerizable monomer containing a polymerizable unsaturated bond-containing N-substituted amide compound represented by the formula: [B] 40 to 99 weight of substantially spherical inorganic particles having an average particle size of more than 0.1 µm and 5 µm or less. % And an average particle size of 0.1%.
A curable composition comprising: an inorganic mixed filler comprising 60 to 1% by weight of inorganic fine particles having a particle size of from 0.1 to 0.1 μm; and [C] a polymerization initiator. 2. [B] The volume of strongly aggregated pores having a pore diameter of 0.08 μm or more in the inorganic mixed filler is 0.1 (cc).
/ G-filler) or less.
The curable composition according to the above. 3. An inorganic mixed filler, wherein [D] particles having an average particle diameter of more than 0.1 μm and 9 μm or less, and particles having a particle diameter of 10 μm or more contain 3% by weight or less of amorphous inorganic particles, and [B] an inorganic mixed filler The curable composition according to claim 1 or 2, wherein the amount of the (D) amorphous inorganic particles is 10 to 300 parts by weight based on 100 parts by weight. 4. A fine particle diameter of 0.08 of [B] an inorganic mixed filler and [D] an inorganic filler composed of amorphous inorganic particles.
The curable composition according to claim 3, wherein the volume of the strongly aggregated pores having a size of μm or more is 0.1 (cc / g-filler) or less. A dental restoration material comprising the curable composition according to any one of claims 1 to 5.