JP5712035B2 - Dental curable composition and cured product thereof - Google Patents

Description

The present invention relates to a dental composition having no polymerization shrinkage (low polymerization shrinkable dental composition) and a low polymerization shrinkable cured product.
More specifically, the present invention is a dental composition suitable for dental use that has no or small polymerization shrinkage and can reduce the occurrence of problems resulting from polymerization shrinkage (low polymerization shrinkable dental composition). The invention relates to a low polymerization shrinkable cured product.

  Dental materials (compositions) are widely used to repair teeth damaged by caries. For example, a dental composition containing a (meth) acrylate group-containing polymerizable compound has been proposed.

  For example, Patent Document 1 discloses a polymerizable substance having a (meth) acrylic acid ester group in a fluorene skeleton. This polymerizable substance has good curability and the polymer is required for a dental material. It has been reported that the mechanical properties are satisfied (Patent Document 1).

  One of the disadvantages of such conventional dental materials is that the dental materials generally shrink when polymerized (cured). Due to the polymerization reaction of the dental material, the monomers are chemically bonded and become a polymer, so that they are more regularly oriented and the molecules tend to be packed more closely together. As a result, the molecules usually constitute a more regular configuration and the volume of the polymeric material is reduced. Such a decrease in the volume of the polymer material caused by polymerization is known as “polymerization shrinkage”. This polymerization shrinkage can cause a number of problems even in dental applications. For example, even if the dental material is polymerized and the dental material and the tooth structure are bonded, a gap may occur between the dental material and the tooth structure due to polymerization shrinkage. This is known to cause postoperative hypersensitivity, microleakage, enamel marginal cracks (white cracks), secondary caries, etc., damaging the repaired tooth and shortening its life. For this reason, there is a demand for a dental material that has no or small polymerization shrinkage and can reduce the occurrence of problems resulting from polymerization shrinkage.

  Dental light comprising 100 parts by weight of a polymerizable monomer, 100 to 400 parts by weight of an inorganic filler, and an effective amount of a photopolymerization initiator in order to compensate for polymerization shrinkage of the (meth) acrylate group-containing polymerizable compound. In the polymerizable composition, 60% by mass or more of particles having a particle size of 0.03 μm or more and less than 0.1 μm among the inorganic filler is silica-zirconia-based spherical inorganic oxide particles. A photopolymerizable composition has been reported (Patent Document 2).

  However, when a large amount of filler is added in order to suppress curing shrinkage, there is a problem that the viscosity rapidly increases and good fluidity cannot be obtained.

JP2007-55977A JP-A-2005-89312

The object of the present invention is to use a metal oxide porous particle as a filler, and in a paste state, a photopolymerizable monomer is filled in the pores of the metal oxide porous particle and released as a host guest compound during polymerization. By acting (FIG. 1), the object is to provide a dental curable composition having a small polymerization shrinkage and a cured product thereof.

That is, the present invention includes the following inventions.
[1] A polymerizable monomer (A), a metal oxide porous particle (B), and a polymerization initiator and / or a sensitizer (C) are included, and the metal oxide porous particle (B) is an average A dental curable composition having a pore diameter of 10 to 300 nm, a specific surface area of 80 m 2 / g or more, and a porosity of 50 volume% or more.

[2] The dental oxide according to [1], wherein the porous structure of the metal oxide porous particles (B) has a cubic phase structure, and the pores are connected with a pore diameter of 3 nm or more. Curable composition.

[3] The metal oxide porous particle (B) contains a metal selected from the group consisting of silicon, titanium, zirconium, yttrium, and aluminum, according to [1] or [2] Dental curable composition.

[4] The polymerizable monomer (A) is a radical photopolymerizable substance, and the polymerization initiator and / or sensitizer is a photopolymerization initiator and / or a photosensitizer. The dental curable composition according to any one of 1] to [3].

[5] 5 to 80% by weight of the metal oxide particles (B) and 0.001 to 10% by weight of the polymerization initiator and / or the sensitizer (C) with respect to the photopolymerizable monomer (A). % Of the dental curable composition according to any one of [1] to [4].

[6] The dental curable composition according to any one of [1] to [5], further comprising an amine compound as a photopolymerization accelerator.

[7] Furthermore, it contains at least one filler selected from the group consisting of inorganic particles other than the metal oxide porous particles (B), organic particles, and organic-inorganic composite particles [1] to [6] ] The dental curable composition in any one of.

[8] A cured product obtained by polymerizing the dental composition according to any one of [1] to [7].

 Low or suitable for use in the field of dental treatment, which can not be solved by conventional dental compositions, has no or small polymerization shrinkage, can reduce the occurrence of problems caused by polymerization shrinkage, and can withstand actual use. A polymerization shrinkable dental composition can be provided.

The schematic diagram by which a metal oxide porous body acts as a host guest compound is shown. The schematic diagram of a stereoregular structure is shown.

The gist of the present invention aimed at solving such problems is as follows.

1. Polymerizable monomer (A)
The polymerizable monomer (A) contained in the low-polymerization shrinkable dental composition of the present invention is not particularly limited as long as it has a (meth) acrylic acid ester group, but initiates radical polymerization with light. The photo radical polymerizable substance (A1) which can be produced is preferable.

  Examples of the radical photopolymerizable substance (A1) include monofunctional (meth) acrylates and polyfunctional (meth) acrylates. Monofunctional (meth) acrylates and polyfunctional (meth) acrylates include those having a linear structure such as alkyl or alkylene in the molecule, those having a ring structure such as an aromatic ring, a cyclo ring, a spiro ring or a condensed ring, oxygen , Nitrogen, sulfur, phosphorus, halogen and other heteroatoms, heterocycles and heteroatom-containing substituents. Further, the photo-radically polymerizable substance (A1) has an acid group or an acid salt or an acid precursor which is easily converted into an acid under conditions during dental restoration treatment in the molecule. May be.

  Specific examples of the photoradical polymerizable substance (A1) include methyl (meth) acrylate, glycidyl (meth) acrylate, 2-cyanomethyl (meth) acrylate, polyethylene glycol mono (meth) acrylate, allyl (meth) acrylate, 2- Hydroxyethyl mono (meth) acrylate, ethylene glycol di (meth) acrylate, diethylene glycol di (meth) acrylate, triethylene glycol di (meth) acrylate, nonaethylene glycol di (meth) acrylate, propylene glycol di (meth) acrylate, di Propylene glycol di (meth) acrylate, bisphenol A diglycidyl ether (meth) acrylic acid adduct, 2,2-bis [4- (meth) acryloyloxyethoxyphenyl] propane 2,2-bis [4- (meth) acryloyloxyethoxyethoxyphenyl] propane, 2,2-bis {4- [3- (meth) acryloyloxy-2-hydroxypropoxy] phenyl} propane, 1,4-butane Examples thereof include (meth) acrylate monomers such as diol di (meth) acrylate, 1,3-hexanediol di (meth) acrylate, urethane di (meth) acrylate, and trimethylolpropane di (meth) acrylate.

  Specific examples of the photo-radical polymerizable substance (A1) having an acidic group in the molecule include (meth) acrylic acid, maleic acid, p-vinylbenzoic acid, 11- (meth) acryloyloxy. -1,1-undecanedicarboxylic acid (MAC-10), 1,4-di (meth) acryloyloxyethyl pyromellitic acid, 6- (meth) acryloyloxyethylnaphthalene-1,2,6-tricarboxylic acid, 4- (Meth) acryloyloxymethyl trimellitic acid and its anhydride, 2,3-bis (3,4-dicarboxybenzoyloxy) propyl (meth) acrylate, N-o-di (meth) acryloyloxytyrosine, N- ( (Meth) acryloyl-p-aminobenzoic acid, N- (meth) acryloyl 4-aminosalicylic acid, N-phenylglycine or N Adducts of tolylglycine and glycidyl (meth) acrylate, 2- (meth) acryloyloxyethyl acid phosphate, 2 and 3- (meth) acryloyloxypropyl acid phosphate, 4- (meth) acryloyloxybutyl acid phosphate, 6- (Meth) acryloyloxyhexyl acid phosphate, 8- (meth) acryloyloxyoctyl acid phosphate, 2-sulfoethyl (meth) acrylate, 2 or 1-sulfo-1 or 2-propyl (meth) acrylate, 1 or 3-sulfo- 2-butyl (meth) acrylate, 3-bromo-2-sulfo-2-propyl (meth) acrylate, 3-methoxy-1-sulfo-2-propyl (meth) acrylate, 1,1-dimethyl-2-sulfoethyl ( Meta) Or the like can be mentioned acrylamide.

2. Metal oxide porous particles (B)
The metal oxide porous particles (B) used in the present invention have 10 to 300 nm pores. The metal is preferably a metal selected from the group consisting of silicon, titanium, zirconium, yttrium, and aluminum. The specific surface area is 80 m ² / g or more, and the porosity is 50 volume% or more. In general, examples of a uniform stereoregular structure include a lamellar phase structure, a hexagonal phase structure, and a cubic phase structure as shown in the schematic diagram of FIG. The lamellar phase structure is a structure in which flat inorganic layers and plate-like air layers are alternately stacked, and the holes are in the form of plate-like layers. The hexagonal phase structure is a structure in which hollow columns (ideally hexagonal columns) are gathered in a honeycomb shape, and is a porous structure in which uniform pores are regularly present at high density. There are several forms of cubic phase structures. Representative examples include Pm3n, Im3m, Fm3m, Fd3m, and Ia3d, Pn3m, Im3m, etc. in which the pores are connected bicontinuously as shown in the schematic diagram of FIG. A cubic phase structure excellent in strength is preferred.

For the pore size, metal oxide porous particles are used as fillers, and in the paste state, the photopolymerizable monomer is filled in the pores of the metal oxide porous particles and acts as a host guest compound released during polymerization. Is preferably 10 nm or more. When the pore diameter is smaller than 10 nm, it is difficult to fill and release the photopolymerizable monomer. When the pore diameter is larger than 300 nm, the particles become brittle, so that it is not preferable to use the composition for a dental material. In order for the photopolymerizable monomer (A) to fill not only the surface of the metal oxide porous particles but also the inside thereof, it is preferable that the pores are connected to each other. The specific surface area is more preferably equal to or greater than ^{80m 2 / g, 85~800m 2 /} g is particularly preferred. The porosity is more preferably 50% by volume or more, and particularly preferably 60 to 90% by volume.

  Metal oxide particles having a cubic phase structure with a pore diameter of 10 to 300 nm or more are polyolefin-based, poly (meth) acrylic acid ester-based, polystyrene-based, polyurethane-based, polyacrylonitrile-based, polyvinyl chloride-based, polyvinylidene chloride-based Removing the water-insoluble organic polymer particles from the water-insoluble organic polymer particles selected from the group consisting of polyvinyl acetate and polybutadiene, and the organic-inorganic composite obtained by the sol-gel reaction of the metal oxide precursor. Is obtained.

  In particular, the metal phase porous particles having a cubic phase structure having a pore diameter of 10 to 30 nm can be stably produced by using, for example, polyolefin terminal branched copolymer particles dispersed in an aqueous medium.

First, the terminal branched copolymer particles will be described. [Polyolefin end-branched copolymer]
The polyolefin terminal branched copolymer constituting the polymer particles used in the present invention has a structure represented by the following general formula (1).

(In the formula, A represents a polyolefin chain. R ¹ and R ² are a hydrogen atom or an alkyl group having 1 to 18 carbon atoms, and at least one of them is a hydrogen atom, and X ¹ and X ² are the same. Or, differently, it represents a group having a linear or branched polyalkylene glycol group.)

The number average molecular weight of the terminal branched copolymer represented by the general formula (1) is 2.5 × 10 ⁴ or less, preferably 5.5 × 10 ^{2 to} 1.5 × 10 ⁴ , more preferably 8 × 10. ^{2 to} 4.0 × 10 ³ . The number average molecular weight is the number average molecular weight of the polyolefin chain represented by A, the number average molecular weight of the group having a polyalkylene glycol group represented by X ¹ and X ² , and R ¹ , R ² and C ₂ H min. It is expressed as the sum of molecular weights.

  When the number average molecular weight of the polyolefin end-branched copolymer is in the above range, the stability of the particles in the dispersion when the polyolefin end-branched copolymer is used as a dispersoid, water and / or affinity with water This is preferable because the dispersibility of the organic solvent in the organic solvent tends to be good and the preparation of the dispersion becomes easy.

  The polyolefin chain which is A in the general formula (1) is obtained by polymerizing an olefin having 2 to 20 carbon atoms. Examples of the olefin having 2 to 20 carbon atoms include α-olefins such as ethylene, propylene, 1-butene and 1-hexene. In the present invention, it may be a homopolymer or copolymer of these olefins, and may be copolymerized with other polymerizable unsaturated compounds as long as the properties are not impaired. Among these olefins, ethylene, propylene, and 1-butene are particularly preferable.

  In general formula (1), the number average molecular weight measured by GPC of the polyolefin chain represented by A is 400 to 8000, preferably 500 to 4000, and more preferably 500 to 2000. Here, the number average molecular weight is a value in terms of polystyrene.

  When the number average molecular weight of the polyolefin chain represented by A is in the above range, the polyolefin portion has high crystallinity, the dispersion tends to be stable, and the melt viscosity is low and the preparation of the dispersion is easy. This is preferable.

  The ratio of the weight average molecular weight (Mw) and the number average molecular weight (Mn) measured by GPC of the polyolefin chain represented by A in the general formula (1), that is, the molecular weight distribution (Mw / Mn) is not particularly limited. However, it is usually 1.0 to several tens, more preferably 4.0 or less, and still more preferably 3.0 or less.

  When the molecular weight distribution (Mw / Mn) of the group represented by A in the general formula (1) is in the above range, it is preferable in terms of the shape of the particles in the dispersion and the uniformity of the particle diameter.

The number average molecular weight (Mn) and molecular weight distribution (Mw / Mn) of the group represented by A by GPC can be measured under the following conditions using, for example, GPC-150 manufactured by Millipore.
Separation column: TSK GNH HT (column size: diameter 7.5 mm, length: 300 mm)
Column temperature: 140 ° C
Mobile phase: Orthodichlorobenzene (Wako Pure Chemical Industries, Ltd.)
Antioxidant: Butylhydroxytoluene (manufactured by Takeda Pharmaceutical Company Limited) 0.025% by mass
Movement speed: 1.0 ml / min Sample concentration: 0.1% by mass
Sample injection volume: 500 microliters Detector: differential refractometer.

  The molecular weight of the polyolefin chain represented by A can be measured by measuring the molecular weight of a polyolefin having an unsaturated group at one terminal, which will be described later, and subtracting the molecular weight corresponding to the terminal.

R ¹ and R ² are a hydrogen atom or a hydrocarbon group having 1 to 18 carbon atoms, which is a substituent bonded to a double bond of the polyolefin constituting A, and preferably a hydrogen atom or a carbon group having 1 to 18 carbon atoms. It is an alkyl group. As the alkyl group, a methyl group, an ethyl group, and a propyl group are preferable.

In the general formula (1), X ¹ and X ² are the same or different and each represents a linear or branched group having a polyalkylene glycol group having a number average molecular weight of 50 to 10,000. The branching mode of the branched alkylene glycol group includes a branching via a polyvalent hydrocarbon group or a nitrogen atom. For example, branching by a hydrocarbon group bonded to two or more nitrogen atoms, oxygen atoms or sulfur atoms in addition to the main skeleton, branching by a nitrogen atom bonded to two alkylene groups in addition to the main skeleton, and the like can be given.

  It is preferable that the number average molecular weight of the group having a polyalkylene glycol group is in the above range because the dispersibility of the dispersion tends to be good and the melt viscosity is low and the preparation of the dispersion is easy.

Since X ¹ and X ^{2 in} the general formula (1) have the above-described structure, a polyolefin-based terminally branched copolymer having a 50% volume average particle diameter of 1 nm to 1000 nm without using a surfactant is used. Polymer particles comprising a polymer are obtained.

In the general formula (1), preferred examples of X ¹ and X ² are the same or different from each other, and the general formula (2),

(In the formula, E represents an oxygen atom or a sulfur atom, X ³ represents a polyalkylene glycol group, or the following general formula (3)

(Wherein R ³ represents an m + 1 valent hydrocarbon group, G is the same or different, and is represented by —OX ⁴ , —NX ⁵ X ⁶ (X ^{4 to} X ⁶ represent a polyalkylene glycol group). M represents the number of bonds between R ³ and G, and represents an integer of 1 to 10.). )
Or general formula (4)

(Wherein X ⁷ and X ⁸ are the same or different and represent a polyalkylene glycol group or a group represented by the above general formula (3)).

In the general formula (3), the group represented by R ³ is an m + 1 valent hydrocarbon group having 1 to 20 carbon atoms. m is 1-10, 1-6 are preferable and 1-2 are especially preferable.

As a preferred example of the general formula (1), there is a polyolefin terminal branched copolymer in which either X ¹ or X ² is a group represented by the general formula (4) in the general formula (1). Can be mentioned. More preferable examples include polyolefin-based terminally branched copolymers in which ^one of X ¹ and X ² is represented by the general formula (4) and the other is a group represented by the general formula (2). It is done.

As another preferable example of the general formula (1), ^one of X ¹ and X ^{2 in} the general formula (1) is a group represented by the general formula (2), and more preferably X ¹ and X ^2. And polyolefin-based terminally branched copolymers in which both are groups represented by the general formula (2).
As a more preferable structure of X ¹ and X ² represented by the general formula (4), the general formula (5)

(Wherein X ⁹ and X ¹⁰ are the same or different and represent a polyalkylene glycol group, and Q ¹ and Q ² are the same or different and each represents a divalent hydrocarbon group). is there.

The divalent hydrocarbon group represented by Q ¹ and Q ² in the general formula (5) is preferably a divalent alkylene group, and more preferably an alkylene group having 2 to 20 carbon atoms. The alkylene group having 2 to 20 carbon atoms may or may not have a substituent, for example, ethylene group, methylethylene group, ethylethylene group, dimethylethylene group, phenylethylene group, chloromethylethylene group, bromo Examples thereof include a methylethylene group, a methoxymethylethylene group, an aryloxymethylethylene group, a propylene group, a trimethylene group, a tetramethylene group, a hexamethylene group, and a cyclohexylene group. A preferable alkylene group is a hydrocarbon-based alkylene group, particularly preferably an ethylene group or a methylethylene group, and still more preferably an ethylene group. Q ¹ and Q ² may be one kind of alkylene group, or two or more kinds of alkylene groups may be mixed.

As a more preferable structure of X ¹ and X ² represented by the general formula (2), the general formula (6)

(Wherein X ¹¹ represents a polyalkylene glycol group).

The polyalkylene glycol group represented by X ^{3 to} X ¹¹ is a group obtained by addition polymerization of alkylene oxide. Examples of the alkylene oxide constituting the polyalkylene glycol group represented by X ^{3 to} X ¹¹ include ethylene oxide, propylene oxide, butylene oxide, styrene oxide, cyclohexene oxide, epichlorohydrin, epibromohydrin, methyl glycidyl ether, allyl A glycidyl ether etc. are mentioned. Of these, propylene oxide, ethylene oxide, butylene oxide, and styrene oxide are preferable. More preferred are propylene oxide and ethylene oxide, and particularly preferred is ethylene oxide. The polyalkylene glycol group represented by X ^{3 to} X ¹¹ may be a group obtained by homopolymerization of these alkylene oxides or a group obtained by copolymerization of two or more kinds. Examples of preferred polyalkylene glycol groups are polyethylene glycol groups, polypropylene glycol groups, or groups obtained by copolymerization of polyethylene oxide and polypropylene oxide, and particularly preferred groups are polyethylene glycol groups.

When X ¹ and X ² in the general formula (1) have the above structure, water and / or an organic solvent having an affinity for water when the polyolefin end-branched copolymer of the present invention is used as a dispersoid. Since dispersibility becomes favorable, it is preferable.

  As the polyolefin-based terminally branched copolymer that can be used in the present invention, a polymer represented by the following general formula (1a) or (1b) is preferably used.

In the formula, R ⁴ and R ⁵ represent a hydrogen atom or an alkyl group having 1 to 18 carbon atoms, and at least one of them is a hydrogen atom. As the alkyl group, an alkyl group having 1 to 9 carbon atoms is preferable, and an alkyl group having 1 to 3 carbon atoms is more preferable.

R ⁶ and R ⁷ represent a hydrogen atom or a methyl group, and at least one of them is a hydrogen atom. R ⁸ and R ⁹ represent a hydrogen atom or a methyl group, and at least one of them is a hydrogen atom.
l + m represents an integer of 2 to 450, preferably 5 to 200.
n represents an integer of 20 or more and 300 or less, preferably 25 or more and 200 or less.

In the formula, R ⁴ and R ⁵ represent a hydrogen atom or an alkyl group having 1 to 18 carbon atoms, and at least one of them is a hydrogen atom. As the alkyl group, an alkyl group having 1 to 9 carbon atoms is preferable, and an alkyl group having 1 to 3 carbon atoms is more preferable.

R ⁶ and R ⁷ represent a hydrogen atom or a methyl group, and at least one of them is a hydrogen atom. R ⁸ and R ⁹ represent a hydrogen atom or a methyl group, and at least one of them is a hydrogen atom. R ¹⁰ and R ¹¹ represent a hydrogen atom or a methyl group, and at least one of them is a hydrogen atom.
l + m + o represents an integer of 3 to 450, preferably 5 to 200.
n represents an integer of 20 to 300, preferably 25 to 200.

  As the polymer represented by the general formula (1b), it is more preferable to use a polymer represented by the following general formula (1c).

In the formula, l + m + o and n are the same as those in the general formula (1b).
The number of ethylene units (n) in the polyethylene chain was calculated by dividing the number average molecular weight (Mn) of the polyolefin group A in the general formula (1) by the molecular weight of the ethylene unit. Further, the total number of ethylene glycol units (l + m or l + m + o) of the polyethylene glycol chain is such that the weight ratio of the polymer raw material to the ethylene oxide used during the polyethylene glycol group addition reaction is the number average molecular weight of the polymer raw material and the polyethylene glycol group (Mn ) And the ratio can be calculated.

N, l + m or l + m + o can also be measured by ¹ H-NMR. For example, in the polyolefin-based terminally branched copolymer (T) used in the examples of the present invention and the dispersion particles containing the same, the terminal methyl group of the polyolefin group A in the general formula (1) (shift value: 0.88 ppm) ) And the integral value of the methylene group of polyolefin group A (shift value: 1.06-1.50 ppm) and the alkylene group of PEG (shift value: 3.33-3.72 ppm) when the integral value of 3 protons is taken. ) Can be calculated from the integral value.

  Specifically, since the molecular weight of the methyl group is 15, the molecular weight of the methylene group is 14, and the molecular weight of the ethylene oxide group is 44, the number average molecular weights of the polyolefin group A and the alkylene group can be calculated from the values of the integrated values. . By dividing the number average molecular weight of the polyolefin group A thus obtained by the molecular weight of the ethylene unit, n is divided by the number average molecular weight of the alkylene group by the molecular weight of the ethylene glycol unit, whereby the total number of ethylene glycol units (l + m Alternatively, l + m + o) can be calculated.

When the polyolefin group A is composed of an ethylene-propylene copolymer, n and l + m or l + m + o can be obtained by using both the propylene content that can be measured by IR, ¹³ C-NMR, and the integral value in ¹ H-NMR. Can be calculated. ^{In 1} H-NMR, a method using an internal standard is also effective.

[Production method of polyolefin end-branched copolymer]
The polyolefin-based terminally branched copolymer can be produced by the following method.
First, in the target polyolefin-based terminally branched copolymer, as a polymer corresponding to the structure of A represented by the general formula (1), the general formula (7)

(Wherein A represents a polyolefin chain, R ¹ and R ² are a hydrogen atom or an alkyl group having 1 to 18 carbon atoms, and at least one of them represents a hydrogen atom.) A polyolefin having a double bond is produced.

This polyolefin can be produced by the following method.
(1) A transition metal compound having a salicylaldoimine ligand as shown in JP-A Nos. 2000-239312, 2001-27331, 2003-73412, etc. is used as a polymerization catalyst. Polymerization method.
(2) A polymerization method using a titanium catalyst comprising a titanium compound and an organoaluminum compound.
(3) A polymerization method using a vanadium catalyst comprising a vanadium compound and an organoaluminum compound.
(4) A polymerization method using a Ziegler-type catalyst comprising a metallocene compound such as zirconocene and an organoaluminum oxy compound (aluminoxane).

  Among the above methods (1) to (4), particularly according to the method (1), the polyolefin can be produced with high yield. In the method (1), a polyolefin having a double bond at one end is produced by polymerizing or copolymerizing the above-described polyolefin in the presence of the transition metal compound having the salicylaldoimine ligand. Can do.

  The polymerization of the polyolefin by the method (1) can be carried out by either a liquid phase polymerization method such as solution polymerization or suspension polymerization or a gas phase polymerization method. Detailed conditions and the like are already known, and the above-mentioned patent documents can be referred to.

  The molecular weight of the polyolefin obtained by the method (1) can be adjusted by allowing hydrogen to be present in the polymerization system, changing the polymerization temperature, or changing the type of catalyst used.

  Next, the polyolefin is epoxidized, that is, the double bond at the terminal of the polyolefin is oxidized to obtain a polymer containing an epoxy group at the terminal represented by the general formula (8).

(In the formula, A, R ¹ and R ² are as described above.)
Although the epoxidation method is not particularly limited, the following methods can be exemplified.
(1) Oxidation with peracids such as performic acid, peracetic acid, perbenzoic acid (2) Oxidation with titanosilicate and hydrogen peroxide (3) Oxidation with rhenium oxide catalyst such as methyltrioxorhenium and hydrogen peroxide ( 4) Oxidation with a porphyrin complex catalyst such as manganese porphyrin or iron porphyrin and hydrogen peroxide or hypochlorite (5) Salen complex such as manganese Salen and oxidation with hydrogen peroxide or hypochlorite (6) Manganese- Oxidation with a TACN complex such as a triazacyclononane (TACN) complex and hydrogen peroxide (7) Oxidation with hydrogen peroxide in the presence of a group VI transition metal catalyst such as a tungsten compound and a phase transfer catalyst The above (1) to (7) Among these methods, the methods (1) and (7) are particularly preferable in terms of the active surface.

For example, VIKOLOX ^™ (registered trademark, manufactured by Arkema) can be used as a low molecular weight terminal epoxy group-containing polymer having a Mw of about 400 to 600.

By reacting the terminal epoxy group-containing polymer represented by the general formula (8) obtained by the above-mentioned method with various reaction reagents, the polymer terminal α, β-position represented by the general formula (9) A polymer (polymer (I)) into which various substituents Y ¹ and Y ² are introduced can be obtained.

(In the formula, A, R ¹ and R ² are as described above. Y ¹ and Y ² are the same or different and represent a hydroxyl group, an amino group, or the following general formulas (10a) to (10c).)

(In the general formulas (10a) to (10c), E represents an oxygen atom or a sulfur atom, R ³ represents an m + 1 valent hydrocarbon group, T represents the same or different hydroxyl group and amino group, and m represents 1 Represents an integer of 10 to 10.)
For example, by hydrolyzing the terminal epoxy group-containing polymer represented by the general formula (8), a polymer in which both Y ¹ and Y ² are hydroxyl groups in the general formula (9) is obtained, and ammonia is reacted. By doing so, a polymer in which ^one of Y ¹ and Y ² is an amino group and the other is a hydroxyl group is obtained.

Further, by reacting the terminal epoxy group-containing polymer represented by the general formula (8) with the reaction reagent A represented by the general formula (11a), ^one of Y ¹ and Y ² in the general formula (9) A polymer having a group represented by the general formula (10a) and the other hydroxyl group is obtained.

(In the formula, E, R ³ , T and m are as described above.)
Further, by reacting the terminal epoxy group-containing polymer with the reaction reagent B represented by the general formulas (11b) and (11c), ^one of Y ¹ and Y ² in the general formula (9) is represented by the general formula (10b) or A polymer having the group shown in (10c) and the other hydroxyl group is obtained.

(Wherein R ³ , T and m are as described above.)
Examples of the reaction reagent A represented by the general formula (11a) include glycerin, pentaerythritol, butanetriol, dipentaerythritol, polypentaerythritol, dihydroxybenzene, and trihydroxybenzene.

  Examples of the reaction reagent B represented by the general formulas (11b) and (11c) include ethanolamine, diethanolamine, aminophenol, hexamethyleneimine, ethylenediamine, diaminopropane, diaminobutane, diethylenetriamine, N- (aminoethyl) propanediamine, and imino. Bispropylamine, spermidine, spermine, triethylenetetramine, polyethyleneimine and the like can be mentioned.

  Addition reactions of epoxy compounds with alcohols and amines are well known and can be easily performed by ordinary methods.

  The general formula (1) can be produced by addition polymerization of alkylene oxide using the polymer (I) represented by the general formula (9) as a raw material. Examples of the alkylene oxide include propylene oxide, ethylene oxide, butylene oxide, styrene oxide, cyclohexene oxide, epichlorohydrin, epibromohydrin, methyl glycidyl ether, and allyl glycidyl ether. Two or more of these may be used in combination. Of these, propylene oxide, ethylene oxide, butylene oxide, and styrene oxide are preferable. More preferred are propylene oxide and ethylene oxide.

For the catalyst, polymerization conditions, etc., known ring-opening polymerization methods of alkylene oxides can be used. For example, Takayuki Otsu, “Chemistry of Revised Polymer Synthesis”, Kagaku Dojin, January 1971, p. . 172-180 discloses an example in which a polyol is obtained by polymerizing various monomers. Catalysts used for ring-opening polymerization include Lewis acids such as AlCl ₃ , SbCl ₅ , BF ₃ , and FeCl ₃ for cationic polymerization and alkali metal hydroxides for anionic polymerization as disclosed in the above document. Alternatively, alkaline earth metal oxides, carbonates, alkoxides, or alkoxides such as Al, Zn, and Fe can be used for alkoxides, amines, phosphazene catalysts, and coordination anionic polymerization. Here, as the phosphazene catalyst, for example, an anion of a compound disclosed in JP-A-10-77289, specifically, a commercially available tetrakis [tris (dimethylamino) phosphoranylideneamino] phosphonium chloride is alkalinized. The thing made into the alkoxy anion using the metal alkoxide etc. can be utilized.

  When a reaction solvent is used, the polymer (I) can be inert to the alkylene oxide, alicyclic hydrocarbons such as n-hexane and cyclohexane, and aromatic hydrocarbons such as toluene and xylene. And ethers such as dioxane, and halogenated hydrocarbons such as dichlorobenzene.

Except for the phosphazene catalyst, the catalyst is used in an amount of preferably 0.05 to 5 mol, more preferably 0.1 to 3 mol, relative to 1 mol of the starting polymer (I). The amount of phosphazene catalyst, polymerization rate, in terms of economy and the like, preferably 1 × ¹⁰ -4 ~5 × ^{10 -1} moles per mole of the polymer (I), more preferably 5 × 10 ^{- 4} is to 1 × ^{10 -1} mol.

The reaction temperature is usually 25 to 180 ° C., preferably 50 to 150 ° C., and the reaction time varies depending on the reaction conditions such as the amount of catalyst used, reaction temperature, reactivity of polyolefins, etc., but is usually several minutes to 50 hours. .

  As described above, the number average molecular weight of the general formula (1) depends on the method of calculating from the number average molecular weight of the polymer (I) represented by the general formula (8) and the weight of the alkylene oxide to be polymerized, or a method using NMR. Can be calculated.

[Polymer particles]
The polymer particles of the present invention comprising such a polyolefin end-branched copolymer have a structure in which the polyolefin chain portion represented by A in the general formula (1) is oriented in the inward direction. This is a rigid particle having a crystalline part.
The polymer particles of the present invention can be dispersed again in a liquid such as a solvent even after removal of the particles by drying the dispersion because the polyolefin chain portion has crystallinity. The polymer particles of the present invention are rigid particles in which the melting point of the polyolefin chain portion contained in the particles is preferably 80 ° C. or higher, more preferably 90 ° C. or higher.
When the melting point of the polyolefin chain portion is in the above range, it becomes a rigid particle having good crystallinity, and even when heated at a higher temperature, the particle collapse is suppressed.

For this reason, since the collapse of the particles is suppressed in the manufacturing process and use scenes in various applications described later, the characteristics of the polymer particles of the present invention are not lost, and the product yield and the product quality are more stable. .
Even when the polymer particles of the present invention are dispersed in a solvent or the like, the particle diameter is constant regardless of the dilution concentration. That is, since it has redispersibility and a uniform dispersed particle size, it is different from micelle particles dispersed in a liquid.

[Polyolefin end-branched copolymer particle dispersion]
The dispersion of the present invention contains the above-mentioned polyolefin-based terminally branched copolymer in a dispersoid, and the dispersoid is dispersed as particles in water and / or an organic solvent having an affinity for water.

In the present invention, the dispersion is a dispersion obtained by dispersing polyolefin terminal branched copolymer particles,
(1) A dispersion containing the polymer particles, which is obtained when producing polyolefin-based terminally branched copolymer particles,
(2) A dispersion obtained by dispersing or dissolving other dispersoids, additives, and the like in the dispersion containing the polymer particles obtained when the polyolefin-based terminally branched copolymer particles are produced,
(3) A dispersion obtained by dispersing polyolefin-based terminally branched copolymer particles in water or an organic solvent having an affinity for water, and dispersing or dissolving other dispersoids or additives,
Any of these are included.

  The content of the polyolefin-based terminally branched copolymer in the dispersion of the present invention is preferably 0.1 to 50% by mass, more preferably 1 to 40% by mass when the total dispersion is 100% by mass. More preferably, it is 1-20 mass%.

  It is preferable that the content ratio of the polyolefin-based terminally branched copolymer is in the above range because the practicality of the dispersion is good, the viscosity can be kept appropriate, and handling becomes easy. The 50% volume average particle diameter of the particles in the dispersion of the present invention is preferably 10 nm or more and 30 nm or less.

  The 50% volume average particle size of the particles can be adjusted by changing the structure of the polyolefin portion and the structure of the terminal branch portion of the polyolefin-based terminal branched copolymer.

  The 50% volume average particle diameter in the present invention means the diameter of a particle when the total volume is 100% when the total volume is 100%, and is a dynamic light scattering particle size distribution measuring device or a microtrack particle size. It can be measured using a distribution measuring device.

  The shape can be observed with a transmission electron microscope (TEM) after negative staining with, for example, phosphotungstic acid.

  The dispersion in the present invention can be obtained by dispersing the polyolefin-based terminally branched copolymer in water and / or an organic solvent having an affinity for water.

  Dispersion in the present invention can be carried out by a method of physically dispersing a polyolefin-based terminally branched copolymer in water and / or an organic solvent having an affinity for water by mechanical shearing force.

  The dispersion method is not particularly limited, but various dispersion methods can be used. Specifically, the polyolefin-based terminally branched copolymer represented by the general formula (1) and water and / or an organic solvent having an affinity for water are mixed and then melted to obtain a high-pressure homogenizer, Examples thereof include a method of dispersing with a homomixer, an extrusion kneader, an autoclave, a method of spraying and pulverizing at a high pressure, and a method of spraying from pores. In addition, after dissolving the polyolefin-based terminally branched copolymer in a solvent other than water in advance, it is mixed with water and / or an organic solvent having an affinity for water and dispersed with a high-pressure homogenizer, a high-pressure homomixer, or the like. A method is also possible. At this time, the solvent used for dissolving the polyolefin end-branched copolymer is not particularly limited as long as the polyolefin end-branched copolymer dissolves, but has an affinity for toluene, cyclohexane or the above water. An organic solvent etc. are mentioned. When it is not preferable that an organic solvent other than water is mixed in the dispersion, it can be removed by an operation such as distillation.

  More specifically, for example, in an autoclave equipped with a stirrer capable of applying a shearing force, a dispersion is obtained by heating and stirring while applying a shearing force at a temperature of 100 ° C. or higher, preferably 120 to 200 ° C. be able to.

  When the temperature is within the above temperature range, the polyolefin end-branched copolymer is in a molten state, so that it can be easily dispersed, and the polyolefin end-branched copolymer is not easily deteriorated by heating.

  The time required for dispersion varies depending on the dispersion temperature and other dispersion conditions, but is about 1 to 300 minutes.

  The above stirring time is preferable because dispersion can be sufficiently performed and the polyolefin-based terminally branched copolymer is hardly deteriorated. After the reaction, it is preferable to maintain a state in which shearing force is applied until the temperature in the dispersion becomes 100 ° C. or lower, preferably 60 ° C. or lower.

  In the production of the dispersion used in the present invention, addition of a surfactant is not indispensable, but for example, an anionic surfactant, a cationic surfactant, an amphoteric surfactant, a nonionic surfactant and the like may coexist.

Anionic surfactants include, for example, carboxylates, simple alkyl sulfonates, modified alkyl sulfonates, alkyl allyl sulfonates, alkyl sulfate esters, sulfated oils, sulfate esters, sulfated fatty acid monoglycerides, sulfated alkanol amides. Sulphated ethers, alkyl phosphate esters, alkyl benzene phosphonates, naphthalene sulfonic acid / formalin condensates.

  Examples of cationic surfactants include simple amine salts, modified amine salts, tetraalkyl quaternary ammonium salts, modified trialkyl quaternary ammonium salts, trialkyl benzyl quaternary ammonium salts, and modified trialkyl benzyl quaternary salts. Examples include quaternary ammonium salts, alkyl pyridinium salts, modified alkyl pyridinium salts, alkyl quinolinium salts, alkyl phosphonium salts, and alkyl sulfonium salts.

  Examples of amphoteric surfactants include betaine, sulfobetaine, sulfate betaine and the like.

Nonionic surfactants include, for example, fatty acid monoglycerin ester, fatty acid polyglycol ester, fatty acid sorbitan ester, fatty acid sucrose ester, fatty acid alkanol amide, fatty acid polyethylene glycol glycol condensate, fatty acid amide polyethylene glycol condensate, Examples include fatty acid alcohol / polyethylene / glycol condensate, fatty acid amine / polyethylene / glycol condensate, fatty acid mercaptan / polyethylene / glycol condensate, alkyl / phenol / polyethylene / glycol condensate, and polypropylene / glycol / polyethylene / glycol condensate. .
These surfactants can be used alone or in combination of two or more.

  In the production of the dispersion used in the present invention, a filtration step may be provided in the process for the purpose of removing foreign substances and the like. In such a case, for example, a stainless steel filter (wire diameter 0.035 mm, plain weave) of about 300 mesh may be installed and pressure filtration (air pressure 0.2 MPa) may be performed.

  The dispersion obtained by the above method has a pH of 1 by adding various acids and bases, for example, acids such as hydrochloric acid, sulfuric acid and phosphoric acid, and bases such as potassium hydroxide, sodium hydroxide and calcium hydroxide. No change or aggregation occurs from 13 to 13. In addition, the dispersion does not aggregate or precipitate even in a wide temperature range in which heating and refluxing or freezing and thawing are repeated under normal pressure.

  The water in the above method is not particularly limited, and distilled water, ion exchange water, city water, industrial water, and the like can be used, but it is preferable to use distilled water or ion exchange water.

  In addition, the organic solvent having an affinity for water in the above method is not particularly limited as long as the dispersoid such as polyolefin-based terminal copolymer particles and surfactant can be dispersed. For example, ethylene glycol, tetraethylene glycol Isopropyl alcohol, acetone, acetonitrile, methanol, ethanol, dimethyl sulfoxide, dimethylformamide, dimethylimidazolidinone and the like. When mixing of the organic solvent into the dispersion is not preferred, the organic solvent can be removed by distillation or the like after preparing a dispersion containing the dispersoid.

  In the dispersion according to the present invention, when the polyolefin terminal branched copolymer is 100 parts by mass, the dispersoid other than the polyolefin terminal branched copolymer is 0.001 part by mass to 20 parts by mass, preferably 0.01 mass part-10 mass parts, More preferably, 0.1 mass part-5 mass parts can be contained.

It is preferable that the content of the dispersoid be in the above range since the physical properties of the dispersion are good in practical use and the dispersion is less likely to aggregate and precipitate.
Cubic phase structure metal oxide porous bodies having an average pore diameter of more than 30 nm and not more than 300 nm can be stably produced by using, for example, poly (meth) acrylate polymer particles dispersed in an aqueous medium. Can do.

Next, the poly (meth) acrylate polymer particles will be described.
[(Meth) acrylic acid ester polymer particle aqueous dispersion]
The poly (meth) acrylate polymer is a homopolymer or copolymer having a repeating unit derived from an acrylate ester and / or a methacrylic ester.
An aqueous dispersion of poly (meth) acrylic acid ester polymer particles is generally called an acrylic emulsion and can be obtained by a known emulsion polymerization method. For example, it can be obtained by emulsion polymerization of an unsaturated monomer (such as an unsaturated vinyl monomer) in water containing a polymerization initiator and a surfactant.

Specific examples of the acrylic ester include methyl acrylate, ethyl acrylate, isopropyl acrylate, n-butyl acrylate, isobutyl acrylate, n-amyl acrylate, isoamyl acrylate, n-hexyl acrylate, 2-ethylhexyl acrylate, octyl acrylate, Examples include decyl acrylate, dodecyl acrylate, octadecyl acrylate, cyclohexyl acrylate, phenyl acrylate, benzyl acrylate, and glycidyl acrylate.
Specific examples of the methacrylic acid ester include methyl methacrylate, ethyl methacrylate, isopropyl methacrylate, n-butyl methacrylate, isobutyl methacrylate, n-amyl methacrylate, isoamyl methacrylate, n-hexyl methacrylate, 2-ethylhexyl methacrylate, octyl methacrylate, decyl methacrylate. , Dodecyl methacrylate, octadecyl methacrylate, cyclohexyl methacrylate, phenyl methacrylate, benzyl methacrylate, glycidyl methacrylate and the like. The poly (meth) acrylic acid ester polymer of the present invention may be copolymerized with an unsaturated monomer other than acrylic acid ester and methacrylic acid ester.

  Unsaturated monomers that can be used in combination include vinyl esters such as vinyl acetate; vinylcyan compounds such as acrylonitrile and methacrylonitrile; halogenated monomers such as vinylidene chloride and vinyl chloride; styrene, α-methylstyrene , Vinyltoluene, 4-t-butylstyrene, chlorostyrene, vinylanisole, vinylnaphthalene and other aromatic vinyl monomers; ethylene, propylene and other olefins; butadiene, chloroprene and other dienes; vinyl ether, vinyl ketone and vinyl Vinyl monomers such as pyrrolidone; unsaturated carboxylic acids such as acrylic acid, methacrylic acid, itaconic acid, fumaric acid and maleic acid; acrylamides such as acrylamide, methacrylamide and N, N′-dimethylacrylamide; 2-hydroxy Ethyl acrylate , 2-hydroxypropyl acrylate, 2-hydroxyethyl methacrylate, hydroxyl group-containing monomers such as 2-hydroxypropyl methacrylate and the like, can be used as a mixture thereof alone or two or more.

A crosslinkable monomer having two or more polymerizable double bonds can also be used. Examples of the crosslinkable monomer having two or more polymerizable double bonds include polyethylene glycol diacrylate, triethylene glycol diacrylate, 1,3-butylene glycol diacrylate, 1,4-butylene glycol diacrylate, 1,6-hexanediol diacrylate, neopentyl glycol diacrylate, 1,9-nonanediol diacrylate, polypropylene glycol diacrylate, 2,2′-bis (4-acryloxypropyloxyphenyl) propane, 2,2 ′ -Diacrylate compounds such as bis (4-acryloxydiethoxyphenyl) propane, triacrylate compounds such as trimethylolpropane triacrylate, trimethylolethane triacrylate, tetramethylolmethane triacrylate Tetraacrylate compounds such as ditrimethylol tetraacrylate, tetramethylol methane tetraacrylate, pentaerythritol tetraacrylate, hexaacrylate compounds such as dipentaerythritol hexaacrylate, ethylene glycol dimethacrylate, diethylene glycol dimethacrylate, triethylene glycol dimethacrylate, polyethylene glycol di Methacrylate, 1,3-butylene glycol dimethacrylate, 1,4-butylene glycol dimethacrylate, 1,6-hexanediol dimethacrylate, neopentyl glycol dimethacrylate, dipropylene glycol dimethacrylate, polypropylene glycol dimethacrylate, polybutylene glycol dimethacrylate Methacrylate, 2, Examples include dimethacrylate compounds such as 2′-bis (4-methacryloxydiethoxyphenyl) propane, trimethacrylate compounds such as trimethylolpropane trimethacrylate and trimethylolethane trimethacrylate, methylenebisacrylamide, and divinylbenzene. It can be used alone or in combination.

In addition to the polymerization initiator and surfactant used in emulsion polymerization, a chain transfer agent, further a neutralizing agent, and the like may be used according to a conventional method. In particular, ammonia and inorganic alkali hydroxides such as sodium hydroxide and potassium hydroxide are preferred as the neutralizing agent.
From the viewpoint of dispersion stability in water, the average particle size of the poly (meth) acrylic acid polymer particles is preferably more than 30 nm and not more than 300 nm, more preferably 40 to 250 nm, and particularly preferably 50 to 200 nm. It is preferable.

Moreover, as a poly (meth) acrylic-acid type polymer particle, any of a single phase structure and a multiphase structure (core shell type) can be used.
The term “acrylic emulsion” is intended to include a solid / liquid dispersion called dispersion, latex, or suspension.
An acrylic emulsion is manufactured as follows, for example.

[Example of production method of acrylic emulsion]
In a reaction vessel equipped with a dropping device, a thermometer, a water-cooled reflux condenser and a stirrer, 100 parts of ion-exchanged water is added, and 0.2 part of a polymerization initiator is added while stirring at a temperature of 70 ° C. in a nitrogen atmosphere. To this, a separately prepared monomer solution is dropped and subjected to a polymerization reaction to prepare a primary substance. Thereafter, at a temperature of 70 ° C., 2 parts of a 10% aqueous solution of a polymerization initiator is added to the primary substance and stirred, and a separately prepared reaction solution is added and stirred to cause a polymerization reaction to obtain a polymerization reaction product. . The polymerization reaction product may be used as it is, or it may be neutralized with a neutralizing agent and adjusted to have a pH of 8 to 8.5. Thereafter, it is filtered through a filter to remove coarse particles, and an acrylic emulsion having resin particles as a dispersoid is obtained.

As the polymerization initiator, those used for normal radical polymerization are used, for example, potassium persulfate, ammonium persulfate, hydrogen peroxide, azobisisobutyronitrile, benzoyl peroxide, dibutyl peroxide, Examples include peracetic acid, cumene hydroperoxide, t-butyl hydroxy peroxide, paramentane hydroxy peroxide, and the like. In particular, as described above, when the polymerization reaction is performed in water, a water-soluble polymerization initiator is preferable.
Moreover, as an emulsifier used by a polymerization reaction, what is generally used as an anionic surfactant, a nonionic surfactant, or an amphoteric surfactant other than sodium lauryl sulfate is mentioned, for example.

Examples of the chain transfer agent used in the polymerization reaction include t-dodecyl mercaptan, n-dodecyl mercaptan, n-octyl mercaptan, xanthogens such as dimethylxanthogen disulfide, diisobutylxanthogen disulfide, dipentene, indene, 1,4- Examples include cyclohexadiene, dihydrofuran, and xanthene.
The acrylic emulsion can be used in combination with an organic solvent in addition to water. As such an organic solvent, those having compatibility with water are preferable. For example, alkyl alcohols having 1 to 4 carbon atoms such as ethanol, methanol, butanol, propanol, isopropanol, ethylene glycol monomethyl ether, ethylene glycol monoethyl, and the like. Ether, ethylene glycol monobutyl ether, ethylene glycol monomethyl ether acetate, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, diethylene glycol mono-n-propyl ether, ethylene glycol mono-iso-propyl ether, diethylene glycol mono-iso-propyl ether, ethylene glycol mono -N-butyl ether, ethylene glycol mono-t-butyl ether, polyethylene Glycol mono-t-butyl ether, 1-methyl-1-methoxybutanol, propylene glycol monomethyl ether, propylene glycol monoethyl ether, propylene glycol mono-t-butyl ether, propylene glycol mono-n-propyl ether, propylene glycol mono-iso- Glycol ethers such as propyl ether, dipropylene glycol monomethyl ether, dipropylene glycol monoethyl ether, dipropylene glycol mono-n-propyl ether, dipropylene glycol mono-iso-propyl ether, 2-pyrrolidone, formamide, acetamide, dimethyl Examples include sulfoxide, sorbit, sorbitan, acetin, diacetin, triacetin, and sulfolane. It can be used alone or in combination of two or more of al.

  Hereinafter, a method for producing a metal oxide porous body using the water-insoluble organic polymer particles described above will be described.

<The manufacturing method of a metal oxide porous body>
The metal oxide porous body of the present invention is produced by forming a water-insoluble organic polymer particle and an organic-inorganic composite of a metal oxide and then removing the water-insoluble organic polymer particle as a template.

Specifically, the following steps are included.
Step (a): A sol-gel reaction of the metal oxide precursor is performed in the presence of the above-described water-insoluble organic polymer particles.
Step (b): The reaction solution obtained in the step (a) is dried to complete the sol-gel reaction to obtain an organic-inorganic composite.
Step (c): The water-insoluble organic polymer particles are removed from the organic-inorganic composite to prepare a metal oxide porous body.

Hereinafter, each process is demonstrated in order.
[Step (a)]
In the step (a), specifically, a solvent that dissolves the water-insoluble organic polymer particles (X), the metal oxide precursor (Y), water and / or a part or all of water in an arbitrary ratio. (Z) is mixed to prepare a mixed composition, and a sol-gel reaction of the metal alkoxide and / or a partially hydrolyzed condensate thereof is performed. The mixed composition may contain a sol-gel reaction catalyst (W) for the purpose of promoting the hydrolysis / polycondensation reaction of the metal alkoxide.

More specifically, the mixed composition is a solution in which the component (Y) or the component (Y) is dissolved in “water and / or a solvent (Z) that dissolves a part or all of water in an arbitrary ratio”. “Sol-gel reaction catalyst (W)”, and if necessary, water is added and stirred and mixed to perform the sol-gel reaction of component (Y), and water-insoluble while continuing this sol-gel reaction It is prepared by adding conductive organic polymer particles (X). The water-insoluble organic polymer particles (X) can be added as an aqueous dispersion.

Further, after adding an aqueous dispersion of water-insoluble organic polymer particles (X) to a solution in which component (Y) or component (Y) is dissolved in the solvent (Z) and stirring and mixing, catalyst (W), Furthermore, it can also prepare by adding water and stirring and mixing as needed.
[Metal oxide precursor (Y)]
Examples of the metal oxide precursor include metal alkoxide and / or a partial hydrolysis condensate thereof, metal halide, metal acetate, metal nitrate, metal sulfate and the like.

The metal alkoxide in this invention points out what is represented by following formula (12).
(R ¹ ) xM (OR ² ) y (12)
In the formula, R ¹ is a hydrogen atom, an alkyl group (methyl group, ethyl group, propyl group, etc.), an aryl group (phenyl group, tolyl group, etc.), a carbon-carbon double bond-containing organic group (acryloyl group, methacryloyl group). And vinyl groups), halogen-containing groups (halogenated alkyl groups such as chloropropyl group and fluoromethyl group), and the like. R ² represents a lower alkyl group having 1 to 6 carbon atoms, preferably 1 to 4 carbon atoms. x and y are x + y = 4 and x represents an integer of 2 or less.

  M includes Li, Na, Mg, Al, Si, K, Ca, Sc, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, Rb, Sr, Y, Nb, Zr, Mo, Ag, Cd, In, Sn, Sb, Cs, Ba, La, Ta, Hf, W, Ir, Tl, Pb, Bi, rare earth metals, etc. are mentioned. From the viewpoint of use as a dental material, Si, Al, Zn A metal (alkoxide) that becomes a colorless metal oxide by a sol-gel reaction, such as Zr, In, Sn, Ti, Pb, and Hf is preferable. Among these, silicon (Si), aluminum (Al), zirconium (Zr), titanium (Ti) and the like are preferably used, and these may be used in combination. Among these, silicon compounds are relatively inexpensive and easy to obtain, and the reaction proceeds slowly, so that the industrial utility value is high. Further, the metal alkoxide and / or its hydrolysis condensate (Y) (hereinafter sometimes referred to as “component (Y)”) undergoes a sol-gel reaction by the addition of water and a catalyst, whereby the metal oxidation described later. The compound used as a thing may be sufficient.

  Specific examples include tetramethoxysilane (TMOS), tetraethoxysilane (TEOS), tetrapropoxysilane, tetraisopropoxysilane, methyltrimethoxysilane, methyltriethoxysilane, methyltripropoxysilane, methyltributoxysilane, ethyl Trimethoxysilane, ethyltriethoxysilane, n-propyltrimethoxysilane, n-propyltriethoxysilane, isopropyltrimethoxysilane, isopropyltriethoxysilane, dimethyldimethoxysilane, dimethyldiethoxysilane, diphenyldimethoxysilane, diphenyldiethoxysilane , Vinyltrimethoxysilane, vinyltriethoxysilane, phenyltrimethoxysilane, phenyltriethoxysilane, p-styryltrimethoxysilane 3-methacryloxypropylmethyldimethoxysilane, 3-methacryloxypropylmethyldiethoxysilane, 3-methacryloxypropyltrimethoxysilane, 3-methacryloxypropyltriethoxysilane, 3-acryloxypropyltrimethoxysilane, 3- Examples include alkoxysilanes such as acryloxypropyltriethoxysilane, 3-chloropropyltriethoxysilane, trifluoromethyltrimethoxysilane and trifluoromethyltriethoxysilane, and alkoxyaluminum, alkoxyzirconium and alkoxytitanium corresponding to these.

Furthermore, in addition to these metal alkoxides, metal alkoxides having various functional groups at R1 as shown in the following 1) to 4) can also be used.
1) 3-aminopropyltrimethoxysilane, 3-aminopropyltriethoxysilane,
3-aminopropylmethyldimethoxysilane, 3-aminopropylmethyldiethoxysilane, N-2- (aminoethyl) -3-aminopropylmethyldimethoxysilane, N-2- (aminoethyl) -3-aminopropyltrimethoxysilane 2-aminoethylaminomethyltrimethoxysilane, 3-aminopropyldimethylethoxysilane, 2- (2-aminoethylthioethyl) triethoxysilane, p-aminophenyltrimethoxysilane, N-phenyl-3-aminopropylmethyl It has an amino group such as dimethoxysilane, N-phenyl-3-aminopropylmethyldiethoxysilane, N-phenyl-3-aminopropyltrimethoxysilane, N-phenyl-3-aminopropyltriethoxysilane, and an alkoxysilyl group. Compound 2) 3 Compounds having a glycidyl group and an alkoxysilyl group such as glycidoxypropylpropyltrimethoxysilane, 3-glycidoxypropylpropyltriethoxysilane, 3-glycidoxypropylmethyldiethoxysilane 3) 3-mercaptopropylmethyldimethoxy Compound having thiol group and alkoxysilyl group such as silane and 3-mercaptopropyltrimethoxysilane 4) Compound having ureido group and alkoxysilyl group such as 3-ureidopropyltrimethoxysilane In the present invention, as metal alkoxide, In the above formula (12), alkoxy silane in which M is silicon (Si), alkoxy zirconium in which M is zirconium (Zr), alkoxy aluminum in which M is aluminum (Al), and M is titanium (Ti Alkoxy titanium is preferably.

  A partially hydrolyzed condensate of metal alkoxide is a compound obtained by polycondensation of one or more of these metal alkoxides partially hydrolyzed using a sol-gel reaction catalyst (W). For example, a partially hydrolyzed polycondensation compound of a metal alkoxide.

  In the present invention, the partially hydrolyzed condensate of metal alkoxide is preferably an alkoxysilane condensate, an alkoxyzirconium condensate, an alkoxyaluminum condensate, or an alkoxytitanium condensate.

As a metal halide in this invention, what is represented by following formula (13) can be used.
(R1) xMZy (13)
In the formula, R1 is a hydrogen atom, an alkyl group (such as a methyl group, an ethyl group, or a propyl group), an alkoxy group (such as a methoxy group, an ethoxy group, a propoxy group, or a butoxy group), an aryl group (such as a phenyl group or a tolyl group) Represents a carbon-carbon double bond-containing organic group (acryloyl group, methacryloyl group, vinyl group and the like), a halogen-containing group (halogenated alkyl group such as chloropropyl group and fluoromethyl group) and the like. Z represents F, Cl, Br, or I. x and y represent an integer such that x + y ≦ 4 and x is 2 or less. M includes Li, Na, Mg, Al, Si, K, Ca, Sc, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, Rb, Sr, Y, Nb, Zr, Mo, Ag, Cd, In, Sn, Sb, Cs, Ba, La, Ta, Hf, W, Ir, Tl, Pb, Bi, rare earth metals, etc. are mentioned. From the viewpoint of use as a dental material, Si, Al, Zn A metal (alkoxide) that becomes a colorless metal oxide by a sol-gel reaction, such as Zr, In, Sn, Ti, Pb, and Hf is preferable. Among these, silicon (Si), aluminum (Al), zirconium (Zr), titanium (Ti) and the like are preferably used, and these may be used in combination.

Specific examples include tetrachloro-dimethyldisilane, chloropropyldichloromethylsilane, chloromethyl (dichloro) methylsilane, di-tert-butyldichlorosilane, dibutyldichlorosilane, dichloro (methyl) -n-octylsilane, dichloro (methyl ) Phenylsilane, dichlorocyclohexylmethylsilane, dichlorodiethylsilane, dichlorodihexylsilane, dichlorodiisopropylsilane, dichlorodimethylsilane, dichlorodiphenylsilane, dichloroethylsilane, dichlorohexylmethylsilane, dichloromethylsilane, dichloromethylvinylsilane, tetrachlorosilane, 1 , 2-bis (trichlorosilyl) ethane, 3-chloropropyltrichlorosilane, allyltrichlorosilane, butyltrichlorosilane, cyclohexyltrichlorosilane Down, ethyl trichlorosilane, hexachlorodisilane, hexachlorodisilane, phenyl trichlorosilane, thexyldimethylsilyl trichlorosilane, trichloromethyl (methyl) silane, trichloro (propyl) silane, trichloro-hexyl, trichlorosilane, trichlorovinylsilane, fluorosilane compounds corresponding to these,
Bromosilanes, iodosilanes, and the corresponding aluminum halides, zirconium halides, titanium halides, cobalt halides, lithium halides, barium halides, iron halides, manganese halides and hydrates thereof Can be mentioned.

In the present invention, examples of the metal acetate include cobalt acetate, cobalt acetoacetate, lithium acetate, lithium acetoacetate, iron acetate, iron acetoacetate, manganese acetate, manganese acetoacetate, and hydrates thereof. Examples of the metal nitrate include cobalt nitrate, lithium nitrate, iron nitrate, manganese nitrate, and hydrates thereof.
Examples of the metal sulfate include titanium sulfate, zirconium sulfate, indium sulfate, zinc sulfate, selenium sulfate, antimony sulfate, tin sulfate, yttrium sulfate, and hydrates thereof.

[Solvent (Z) that dissolves water and / or a part or all of water in an arbitrary ratio]
In the composition of the present invention, the component (Z) is added for the purpose of further hydrolyzing the metal alkoxide and / or its partial hydrolysis condensate (Y), metal halide, metal acetate, and metal nitrate.

  In addition, the component (Z) includes a solvent used when an aqueous dispersion is obtained using a water-insoluble organic polymer, an aqueous dispersion, the component (Y), and a sol-gel reaction catalyst (W) (hereinafter described) , Sometimes referred to as “component W”).

  The water is not particularly limited, and distilled water, ion exchange water, city water, industrial water, and the like can be used, but it is preferable to use distilled water or ion exchange water.

  The solvent for dissolving a part or all of water in an arbitrary ratio is not particularly limited as long as it is an organic solvent having an affinity for water and can disperse the water-insoluble organic polymer. Ethanol, propyl alcohol, isopropyl alcohol, acetone, acetonitrile, dimethyl sulfoxide, dimethylformamide, dimethylimidazolidinone, ethylene glycol, tetraethylene glycol, dimethylacetamide, N-methyl-2-pyrrolidone, tetrahydrofuran, dioxane, methyl ethyl ketone, cyclohexanone, cyclo Examples include pentanone, 2-methoxyethanol (methyl cellosolve), 2-ethoxyethanol (ethyl cellosolve), and ethyl acetate. Among these, methanol, ethanol, propyl alcohol, isopropyl alcohol, acetonitrile, dimethyl sulfoxide, dimethylformamide, acetone, tetrahydrofuran, and dioxane are preferable because of their high affinity with water.

  When water is used, the amount of water to be added is usually in the range of, for example, 1 part by weight or more and 1000000 parts by weight or less, preferably 10 parts by weight, with respect to 100 parts by weight of the mixture of the component (Z) and the component (W). It is the range of not less than 10000 parts by weight.

  As a solvent for dissolving a part or all of water in an arbitrary ratio, the amount of the solvent to be added is usually 1 part by weight or more with respect to 100 parts by weight of the mixture of component (Z) and component (W). The range is 1 million parts by weight or less, preferably 10 parts by weight or more and 10,000 parts by weight or less.

Moreover, the preferable reaction temperature at the time of hydrolysis polycondensation of metal alkoxides is 1 ° C. or more and 100 ° C. or less, more preferably 20 ° C. or more and 60 ° C. or less, and the reaction time is 10 minutes or more and 72 hours or less, More preferably, it is 1 hour or more and 24 hours or less.
[Sol-gel reaction catalyst (W)]
In the mixed composition used in the present invention, for the purpose of accelerating the reaction in the hydrolysis / polycondensation reaction of the metal alkoxide, it may contain a catalyst that can be a catalyst for the hydrolysis / polycondensation reaction as shown below.

  What is used as a catalyst for the hydrolysis and polycondensation reaction of metal alkoxides is “functional thin film production technology by the latest sol-gel method” (Satoru Hirashima, General Technology Center, page 29) and “sol-gel” It is a catalyst used in a general sol-gel reaction described in “Science of Law” (Sakuo Sakuo, Agne Jofu Co., Ltd., page 154).

  As the catalyst (W), acid catalyst, alkali catalyst, organotin compound, titanium tetraisopropoxide, diisopropoxytitanium bisacetylacetonate, zirconium tetrabutoxide, zirconium tetrakisacetylacetonate, aluminum triisopropoxide, aluminum tris Examples thereof include metal alkoxides such as ethyl acetonate and trimethoxyborane.

  Among these catalysts, acid catalysts and alkali catalysts are preferably used. Specifically, acid catalysts include hydrochloric acid, nitric acid, sulfuric acid, phosphoric acid, acetic acid, succinic acid, tartaric acid, toluenesulfonic acid and other inorganic and organic acids, and alkali catalysts include ammonium hydroxide, potassium hydroxide and sodium hydroxide. Alkali metal hydroxide, quaternary ammonium hydroxide such as tetramethylammonium hydroxide, tetraethylammonium hydroxide, tetrabutylammonium hydroxide, ammonia, triethylamine, tributylamine, morpholine, pyridine, piperidine, ethylenediamine, diethylenetriamine, ethanolamine , Amines such as diethanolamine and triethanolamine, aminosilanes such as 3-aminopropyltriethoxysilane and N (2-aminoethyl) -3-aminopropyltrimethoxysilane Etc., and the like.

  From the standpoint of reactivity, it is preferable to use an acid catalyst such as hydrochloric acid or nitric acid, where the reaction proceeds relatively gently. The amount of the catalyst used is preferably 0.001 mol or more and 0.05 mol or less, preferably 0.001 mol or more and 0.04 mol or less, more preferably 0.001 with respect to 1 mol of the metal alkoxide of component (Y). The degree is not less than mol and not more than 0.03 mol.

  The mixed composition in the step (a) can be used, for example, in the form of a sol-gel reactant obtained by performing a sol-gel reaction without removing the solvent (Z) in the presence of the catalyst (W). .

[Step (b)]
In the step (b), the reaction solution (mixed composition) obtained in the step (a) is dried to obtain an organic-inorganic composite.

  As a method for producing the composite particles, the mixed dispersion of the present invention is heated and dried at a predetermined temperature to remove water or the solvent, and then the obtained solid is formed by a treatment such as pulverization or classification, or a freeze-drying method. After removing water or solvent at a low temperature and drying, the resulting solid is further heated and dried at a predetermined temperature, and the resulting solid is formed by pulverization or classification, and further a composite of 10 μm or less by a spray dryer. There is a method of obtaining powder by spraying body fine particles with a spray drying device (spray dryer) and volatilizing the solvent.

  That is, the sol-gel reaction is completed by heating and drying the mixed composition (reaction solution), a metal oxide is obtained from the component (Y), and a matrix mainly composed of this metal oxide is formed. The heating temperature for completing the sol-gel reaction is from room temperature to 300 ° C., more preferably from 80 ° C. to 200 ° C. The organic-inorganic composite has a structure in which water-insoluble organic polymer fine particles are dispersed in this matrix.

The state in which the sol-gel reaction is completed is ideally a state in which all M-O-M bonds are formed, but some alkoxyl groups (M-OR ² ) and M-OH groups are partially formed. Although it remains, it includes a state in which it has shifted to a solid (gel) state.

[Step (c)]
In the step (c), the organic polymer particles are removed from the organic-inorganic composite obtained in the step (b) to prepare a metal oxide porous body.

As a method for removing organic polymer particles, a method of decomposing and removing by firing, a method of decomposing and removing by irradiating with VUV light (vacuum ultraviolet light), far infrared rays, microwaves and plasma, and extraction and removing using a solvent or water. The method etc. are mentioned. When decomposing and removing by firing, a preferable temperature is 200 ° C to 1000 ° C, more preferably 300 ° C to 700 ° C. If the calcination temperature is too low, the organic polymer particles are not removed, whereas if it is too high, the pores may collapse due to being close to the melting point of the metal oxide. Firing may be performed at a constant temperature, or may be gradually raised from room temperature. The firing time can be changed according to the temperature, but it is preferably performed in the range of 1 hour to 24 hours. Firing may be performed in air or in an inert gas such as nitrogen or argon. Moreover, you may carry out under reduced pressure or in a vacuum. In the case of irradiating and removing by VUV light, a VUV lamp, an excimer laser, or an excimer lamp can be used. May be used in combination with oxidation action of ozone (O ₃₎ generated at the time of irradiating the VUV light in air. As the microwave, any frequency of 2.45 GHz or 28 GHz may be used. The output of the microwave is not particularly limited, and a condition for removing the water-insoluble organic polymer particles is selected.

When extraction is performed using a solvent or water, for example, ethylene glycol, tetraethylene glycol, isopropyl alcohol, acetone, acetonitrile, methanol, ethanol, cyclohexane, dimethyl sulfoxide, dimethylformamide, dimethylimidazolidinone, xylene, toluene , Chloroform, dichloromethane and the like can be used. The extraction operation may be performed under heating. Further, ultrasonic (US) treatment may be used in combination. In addition, after performing extraction operation, in order to remove the water | moisture content and solvent which remain | survive in a pore, it is preferable to perform heat processing under reduced pressure.
The metal oxide porous particles of the present invention thus obtained have uniform pores, and the average pore diameter is 10 to 300 nm, preferably 10 to 200 nm. The metal oxide porous body of the present invention is a mesoporous structure and preferably exhibits a cubic structure.

  Although the reason why the metal oxide porous body in which the pores form a cubic phase structure is obtained by using the organic polymer particles as a template is not clear, it is presumed as follows.

  In the step (a) of the above-mentioned “metal oxide porous body production method”, when a plurality of water-insoluble organic polymer particles are added while performing the sol-gel reaction of the metal oxide precursor, The organic polymer particles repel each other by a predetermined surface charge, and are dispersed in a thermodynamically stable state with a predetermined distance, that is, a cubic structure such as Fm3m.

  Therefore, the pores of the metal oxide porous particles formed by removing the water-insoluble organic polymer particles dispersed in this way by calcination form a cubic phase.

  Here, the structure and average pore diameter of the surface of the metal oxide porous body can be evaluated and measured by a scanning electron microscope, and the structure and average pore diameter inside the metal oxide porous particles are measured by a transmission electron microscope (TEM). Thus, it is possible to evaluate and measure by appropriately setting the visual field range according to the dispersion state of the pores, measuring the diameter of the pores within the visual field range, and averaging.

  The pore volume (ml / g) of the metal oxide porous particles can be determined by nitrogen adsorption. The nitrogen adsorption / desorption measurement of the particles is measured using Autosorb 3 (manufactured by Cantachrome), and the total pore volume can be calculated by the BJH (Barrett-Joyner-Halenda) method. Furthermore, the porosity (volume%) and bulk specific gravity can be calculated from the value of the total pore volume obtained.

  The metal oxide porous particles (B) may be treated with a surface treatment agent typified by a silane coupling agent in order to improve the compatibility with the polymerizable monomer and improve the mechanical strength and water resistance. good.

  The surface treatment may be carried out by a known method. Examples of the silane coupling agent include methyltrimethoxysilane, methyltriethoxysilane, methyltrichlorosilane, dimethyldichlorosilane, trimethylchlorosilane, vinyltrimethoxysilane, vinyltriethoxysilane. , Vinyltrichlorosilane, vinyltriacetoxysilane, vinyltris (2-methoxyethoxy) silane, 3-methacryloyloxypropyltrimethoxysilane, 3-methacryloyloxypropyltris (2-methoxyethoxy) silane, 3-chloropropyltrimethoxysilane, 3-chloropropylmethyldimethoxysilane, 3-glycidyloxypropyltrimethoxysilane, 3-glycidyloxypropylmethyldiethoxysilane, 2- (3,4-epoxy Chlohexyl) ethyltrimethoxysilane, 5,6-epoxyhexyltriethoxysilane, 3-ethyl-3- [3- (triethoxysilyl) propoxymethyl] oxetane, N-phenyl-γ-aminopropyltrimethoxysilane, hexamethyl Disilazane and the like are preferably used. Particularly when the polymerizable monomer is a cationic polysynthetic monomer, 3-glycidyloxypropyltrimethoxysilane, 3-glycidyloxypropylmethyldiethoxysilane, which is a silane coupling agent having a cationic polymerizable functional group, 2- (3,4-epoxycyclohexyl) ethyltrimethoxysilane, 5,6-epoxyhexyltriethoxysilane, 3-ethyl-3- [3- (triethoxysilyl) propoxymethyl] oxetane and the like are desirable. The silane coupling agent can be used alone or in combination of two or more.

  Although the usage-amount of the metal oxide porous particle (B) of this invention is not specifically limited, 5 to 80 weight% is preferable with respect to a photopolymerizable monomer (A), and 10 to 70 weight% is. More preferred.

3. Polymerization initiator and / or sensitizer (C)
As the polymerization initiator and / or sensitizer (C), benzyl, camphor-quinone, α-naphthyl, p, p′-dimethoxybenzyl, pentadione, 1,4-phenanthrenequinone, naphthoquinone, trimethylbenzoyldiphenylphosphine oxide , Bis (η-5-2,4-cyclopentadien-1-yl) -bis (2,6-difluoro-3- (1H
-Pyrrol-1-yl) -phenyl) titanium, etc. Known α-diketone compounds and phosphorus atom-containing compounds, titanium atom-containing compounds, benzophenones, benzoin alkyls that are excited by irradiation with visible light or ultraviolet light to initiate polymerization Examples include photopolymerization initiators such as ketals and / or photosensitizers. These compounds may be used alone or in combination of two or more.
Moreover, a photopolymerization accelerator can be used together if desired.

  Photopolymerization accelerators include tertiary amines such as N, N-dimethylaniline, N, N-diethylaniline, N, N-dibenzylaniline, N, N-dimethyl-p-toluidine; Combinations of amines with citric acid, malic acid and 2-hydroxypropanoic acid; barbituric acids such as 5-butylaminobavirturic acid and 1-benzyl-5-phenylbavirtururic acid; benzoyl peroxide, di-tert -Organic peroxides such as butyl peroxide are exemplified. These compounds may be used alone or in combination of two or more.

  Among these compounds, ethyl pN, N-dimethylaminobenzoate, methyl pN, N-dimethylaminobenzoate, 2-n-butoxyethyl pN, N-dimethylaminobenzoate, N, N- A tertiary aromatic amine in which a nitrogen atom is directly bonded to an aromatic such as dimethylaminoethyl methacrylate or an aliphatic tertiary amine having a polymerizable group is a preferred compound.

  In order to quickly complete the curing, it is preferable to use a combination of a photosensitizer and a photopolymerization accelerator. It is preferably used in combination with an ester compound of a tertiary aromatic amine in which a nitrogen atom is directly bonded to an aromatic such as ethyl or p-N, N-dimethylaminobenzoic acid 2-n-butoxyethyl.

Organic peroxides and diazo compounds can also be used as the polymerization initiator.
Examples of organic peroxides include diacyl peroxides such as diacetyl peroxide, diisobutyl peroxide, didecanoyl peroxide, benzoyl peroxide, and succinic acid peroxide; diisopropyl peroxydicarbonate, di-2-ethylhexyl peroxide Peroxydicarbonates such as dicarbonate and diallylperoxydicarbonate; Peroxyesters such as tert-butylperoxyisobutyrate, tert-butylneodecanate and cumeneperoxyneodecanate; acetylcyclohexylsulfonyl peroxide And peroxide sulfonates.

  Examples of diazo compounds include 2,2′-azobisisobutyronitrile, 4,4′-azobis (4-cyanovaleric acid), 2,2′-azobis (4-methoxy-2,4-dimethoxy). Valeronitrile), 2,2′-azobis (2-cyclopropylpropionitrile), and the like.

  When it is desired to complete the polymerization in a short time, a compound having a decomposition half-life at 80 ° C. of 10 hours or less is preferable. Among the above compounds, benzoyl peroxide and 2,2′-azobisisobutyronitrile are Preferred compounds.

  When a redox initiator system is used as the polymerization initiator, there is no particular limitation, and various known initiators are used.

Combination of organic peroxide and tertiary amine; organic peroxide / sulfinic acid or alkali metal salt thereof / tertiary amine combination; inorganic peroxide such as potassium persulfate and sodium sulfite, inorganic peroxide And a combination of an inorganic peroxide such as sodium hydrogen sulfite and an inorganic reducing agent. Among these, benzoyl peroxide and N, N-dimethyl-p-toluidine, benzoyl peroxide and N, N-dihydroxyethyl-p-toluidine are preferably used.

The amount of the polymerization initiator and / or sensitizer (C) used is not particularly limited, but is usually in the range of 0.001 to 10% by weight with respect to the polymerizable monomer (A). Preferably, it exists in the range of 0.001 to 5 weight%.
In the dental composition of the present invention, fillers other than the metal oxide porous particles (B) can be included as a compounding component, but such fillers are not particularly limited, and are generally known inorganic particles and organic particles. And organic-inorganic composite particles.

  Examples of the inorganic particles include amorphous silica, silica-titania, silica-zirconia, silica-titania-barium oxide, quartz, alumina, and the like. Furthermore, a small amount of Group I metal oxides are present in the inorganic oxide particles for the purpose of easily obtaining dense inorganic oxide particles when these inorganic oxide particles are fired at a high temperature. It is also possible to use mixed oxide particles. For dental use, inorganic particles of composite oxides mainly composed of silica and zirconia have X-ray contrast properties, and thus are particularly preferably used.

  The particle size and shape of these inorganic particles are not particularly limited, and spherical or amorphous fillers having an average particle size of 0.01 μm to 100 μm, which are generally used as dental materials, can be appropriately used depending on the purpose. That's fine. Further, the refractive index of these particles is not particularly limited, and those having a particle range of 1.4 to 1.7 which particles of a general dental composition have can be used without limitation. Among them, in order to obtain higher surface smoothness and wear resistance, it is preferable to use a spherical or substantially spherical inorganic powder and / or an aggregate thereof.

  The particle diameter of the inorganic spherical particles is not particularly limited, but in order to obtain higher surface smoothness and wear resistance, the inorganic particles having an average particle diameter of 0.01 μm to 1 μm and / or the It is preferable to use inorganic spherical particles made of an aggregate of inorganic particles. These inorganic spherical particles can be used in a single particle system and a mixed particle system composed of two or more groups having different average particle sizes.

In addition, organic-inorganic composite particles can be suitably used for the purpose of achieving both a higher particle filling rate and good operability. Organic-inorganic composite particles are those obtained by polymerizing and curing a polymerizable monomer and a polymerization curable composition containing inorganic particles as main components, and are obtained by pulverization. Inorganic composite particles are used without any limitation.
These particles may be used alone or in combination of two or more.

By blending fillers other than these metal oxide porous particles (B) with the dental composition of the present invention, the polymerization shrinkage can be further reduced, or the operability of the dental composition before curing. Or improvement in mechanical properties after curing.
The amount of the filler is preferably in the range of 1 to 100 parts by weight, more preferably 100 parts by weight with respect to the total amount of the photopolymerizable monomer (A) and the metal oxide porous particles (B). Is in the range of 3-50 parts by weight.

Furthermore, these fillers such as inorganic particles and organic-inorganic composite particles may be used alone or in combination with a plurality of types having different materials, particle sizes, shapes, etc. In view of excellent physical properties, it is particularly preferable to use inorganic particles alone or in combination of inorganic particles and organic-inorganic composite particles.

Furthermore, the dental composition of the present invention includes a stabilizer such as a polymerization inhibitor, an antioxidant, and an ultraviolet absorber, other dyes, antistatic agents, pigments, fragrances, organic compounds, as long as the effects of the present invention are not impaired. Known additives such as solvents and thickeners may be blended.
The dental composition of the present invention is particularly suitably used as a dental restoration material as described above, but is not limited thereto, and is used in other dental treatment fields such as dental adhesives and denture base materials. Can also be used for applications.

  EXAMPLES Hereinafter, the present invention will be described more specifically with reference to examples. However, the scope of the present invention is not limited to these examples.

<Formation of porous silica particles-1>
<Synthesis of polyolefin end-branched copolymer>
Number average molecular weight (Mn), weight average molecular weight (Mw), and molecular weight distribution (Mw / Mn) were measured by GPC using the method described in the text. Moreover, the peak top temperature obtained by measuring using DSC was employ | adopted for melting | fusing point (Tm). In addition, although melting | fusing point of a polyalkylene glycol part is also confirmed by measurement conditions, here, unless there is particular notice, it refers to melting | fusing point of a polyolefin part. ¹ H-NMR was measured at 120 ° C. after completely dissolving the polymer in deuterated 1,1,2,2-tetrachloroethane serving as a lock solvent and a solvent in a measurement sample tube. . The chemical shift was determined by setting the peak of deuterated 1,1,2,2-tetrachloroethane to 5.92 ppm and determining the chemical shift value of other peaks. As for the particle diameter of the particles in the dispersion, a 50% volume average particle diameter was measured with Microtrac UPA (manufactured by HONEYWELL). The shape of the particles in the dispersion was observed by diluting the sample 200 to 500 times, negatively staining with phosphotungstic acid, and then using a transmission electron microscope (TEM / H-7650 manufactured by Hitachi, Ltd.) at 100 kV. I did it.

(Synthesis of polyolefin end-branched copolymer (T))
A terminal epoxy group-containing ethylene polymer (E) was synthesized according to the following procedure (for example, see Synthesis Example 2 of JP-A-2006-131870).

A stainless steel autoclave with an internal volume of 2000 ml sufficiently purged with nitrogen was charged with 1000 ml of heptane at room temperature, and the temperature was raised to 150 ° C. Subsequently, 30 kg / cm ² G was pressurized with ethylene in the autoclave to maintain the temperature. A hexane solution (1.00 mmol / ml of aluminum atom equivalent) of MMAO (manufactured by Tosoh Finechem) was injected with 0.5 ml (0.5 mmol), and then a toluene solution (0.0002 mmol / ml) of a compound of the following formula: 0.5 ml (0.0001 mmol) was injected to initiate the polymerization. After carrying out the polymerization at 150 ° C. for 30 minutes in an ethylene gas atmosphere, the polymerization was stopped by press-fitting a small amount of methanol. The obtained polymer solution was added to 3 liters of methanol containing a small amount of hydrochloric acid to precipitate a polymer. After washing with methanol, it was dried under reduced pressure at 80 ° C. for 10 hours to obtain a single-end double bond-containing ethylene polymer (P).

In a 500 ml separable flask, 100 g of the ethylene polymer (P) containing one end double bond (Mn850, vinyl group 108 mmol), 300 g of toluene, 0.85 g (2.6 mmol) of Na ₂ WO ₄ , CH ₃ (nC ₈ H ₁₇ ) ₃ NHSO ₄ (0.60 g, 1.3 mmol) and phosphoric acid (0.11 g, 1.3 mmol) were charged, and the mixture was heated to reflux with stirring for 30 minutes to completely melt the polymer. After the internal temperature was set to 90 ° C., 37 g (326 mmol) of 30% hydrogen peroxide solution was added dropwise over 3 hours, and the mixture was stirred at an internal temperature of 90 to 92 ° C. for 3 hours. Thereafter, 34.4 g (54.4 mmol) of a 25% aqueous sodium thiosulfate solution was added while maintaining the temperature at 90 ° C., and the mixture was stirred for 30 minutes. The peroxide in the reaction system was completely decomposed with the peroxide test paper. It was confirmed. Subsequently, 200 g of dioxane was added at an internal temperature of 90 ° C. to crystallize the product, and the solid was collected by filtration and washed with dioxane. The obtained solid was stirred in a 50% aqueous methanol solution at room temperature, and the solid was collected by filtration and washed with methanol. Further, the solid was stirred in 400 g of methanol, collected by filtration and washed with methanol. By drying under reduced pressure of room temperature and 1-2 hPa, 96.3 g of white solid of terminal epoxy group-containing ethylene polymer (E) was obtained (yield 99%, polyolefin conversion rate 100%).

The obtained terminal epoxy group-containing ethylene polymer (E) was Mw = 2058, Mn = 1118, Mw / Mn = 1.84 (GPC). (Terminal epoxy group content: 90 mol%)
¹ H-NMR: δ (C2D2Cl4) 0.88 (t, 3H, J = 6.92 Hz), 1.18-1.66 (m), 2.38 (dd, 1H, J = 2.64, 5.28 Hz), 2.66 (dd, 1H, J = 4.29, 5.28 Hz), 2.80-2.87 (m, 1H)
Melting point (Tm) 121 ℃
Mw = 2058, Mn = 1118, Mw / Mn = 1.84 (GPC)

A 1000 mL flask was charged with 84 parts by weight of a terminal epoxy group-containing ethylene polymer (E), 39.4 parts by weight of diethanolamine, and 150 parts by weight of toluene, and stirred at 150 ° C. for 4 hours. Thereafter, acetone was added while cooling to precipitate the reaction product, and the solid was collected by filtration. The obtained solid was stirred and washed once with an aqueous acetone solution and further three times with acetone, and then the solid was collected by filtration. Thereafter, the polymer (I) (Mn = 1223, A: group formed by polymerization of ethylene (Mn = 1075) in the general formula (9) (Mn = 1075), R ¹ = R ² = by drying under reduced pressure at room temperature. A hydrogen atom, ^one of Y ¹ and Y ² was a hydroxyl group, and the other was a bis (2-hydroxyethyl) amino group).
¹ H-NMR: δ (C2D2Cl4) 0.88 (t, 3H, J = 6.6 Hz), 0.95-1.92 (m), 2.38-2.85 (m, 6H), 3.54-3.71 (m, 5H)
Melting point (Tm) 121 ℃

A 500 mL flask equipped with a nitrogen introduction tube, a thermometer, a cooling tube, and a stirrer is charged with 20.0 parts by weight of polymer (I) and 100 parts by weight of toluene and heated in an oil bath at 125 ° C. while stirring to obtain a solid. Was completely dissolved. After cooling to 90 ° C., 0.323 parts by weight of 85% KOH previously dissolved in 5.0 parts by weight of water was added to the flask and mixed for 2 hours under reflux conditions. Thereafter, water and toluene were distilled off while gradually raising the temperature in the flask to 120 ° C. Further, while supplying a slight amount of nitrogen to the flask, the pressure in the flask was reduced, and the internal temperature was raised to 150 ° C. and maintained for 4 hours to further distill off water and toluene in the flask. After cooling to room temperature, the solidified solid in the flask was crushed and taken out.

A stainless steel 1.5 L pressure reactor equipped with a heating device, a stirring device, a thermometer, a pressure gauge, and a safety valve was charged with 18.0 parts by weight of the obtained solid and 200 parts by weight of dehydrated toluene. After substituting with nitrogen, the temperature was raised to 130 ° C. with stirring. After 30 minutes, 9.0 parts by weight of ethylene oxide was added, and the mixture was further maintained at 130 ° C. for 5 hours, and then cooled to room temperature to obtain a reaction product. A solvent is removed from the obtained reaction product by drying, and a polyolefin-based terminally branched copolymer (T) (Mn = 1835, in formula (1), A: a group formed by polymerization of ethylene (Mn = 1075)). , R ¹ = R ² = hydrogen atom, ^one of X ¹ and X ² is a group represented by the general formula (6) (X ¹¹ = polyethylene glycol group), and the other is a group represented by the general formula (5) (Q ¹ = Q ² = ethylene group, X ⁹ = X ¹⁰ = polyethylene glycol group)).
¹ H-NMR: δ (C2D2Cl4) 0.88 (3H, t, J = 6.8 Hz), 1.06-1.50 (m), 2.80-3.20 (m), 3.33-3.72 (m)
Melting point (Tm) -16 ° C (polyethylene glycol), 116 ° C

<Preparation example of polyolefin end-branched copolymer aqueous dispersion>
(Preparation of 10% by weight polyolefin end-branched copolymer (T) aqueous dispersion)
10 parts by weight of the polyolefin end branched copolymer (T) obtained in the above synthesis example and 40 parts by weight of distilled water were charged into a 100 ml autoclave, heated and stirred at 140 ° C. and 800 rpm for 30 minutes, The mixture was cooled to room temperature while maintaining stirring. The obtained dispersion had a volume 50% average particle size of 0.018 μm. (Volume 10% average particle diameter 0.014 μm, volume 90% average particle diameter 0.022 μm) The particle diameter measured from the transmission electron microscope observation result of the obtained dispersion was 0.015-0.030 μm. Further, 75 parts by weight of distilled water is added to 75 parts by weight of this (T) aqueous dispersion (solid content: 20% by weight) to obtain a 10% by weight polyolefin-based terminally branched copolymer (T) aqueous dispersion. It was.

(Preparation of polyolefin end-branched copolymer / TMOS dehydrated condensate solution)
15 parts by weight of methanol as a solvent was added to 10 parts by weight of tetramethoxysilane (TMOS) and stirred at room temperature. Further, 2 parts by weight of 1M oxalic acid aqueous solution of the catalyst was added dropwise (to make the pH after addition of the polyolefin end-branched copolymer about 3), and then stirred at room temperature to obtain a dehydrated condensate of TMOS.

  To the resulting dehydrated condensate of TMOS, 73 parts by weight of an aqueous dispersion of polyolefin-based terminally branched copolymer (T) (solid content 10% by weight) was added dropwise and stirred at room temperature. A polymer / TMOS dehydrated condensate solution was prepared. (Polyolefin end-branched copolymer / silica: SiO2 weight ratio is 65/35)

The silica content indicates the proportion of silica contained in the composite particles, and was calculated by the following method. The silica content was calculated on the assumption that 100% by weight of TMOS reacted to become SiO2. That is, TMOS: Mw = 152
SiO2: Mw = 60
Than,
SiO2 / TMOS = 60/152 = 0.395. That is, the value obtained by multiplying the amount of TMOS added by 0.395 is the SiO2 content in the particles.

(Formation of polyolefin end-branched copolymer / silica composite particles)
This composition was poured into a spray dryer apparatus (spray dryer ADL311S manufactured by Yamato Scientific Co., Ltd.), pressurized (0.2 MPa) at a nozzle outlet temperature of 190 ° C., and sprayed to obtain a polyolefin end-branched copolymer / silica. Composite fine particles were obtained.

(Formation of silica porous particles (S-1))
The polyolefin end-branched copolymer / silica composite particles obtained were heated at a rate of 5 ° C. per minute from room temperature to 600 ° C. using an electric furnace, and further baked at 600 ° C. for 2 hours. The system terminal branched copolymer was removed to obtain porous silica particles (S-1). The particle diameter was observed using a scanning electron microscope (JSM-6701F type manufactured by SEM / JEOL) under the condition of 1.5 kV. As a result, spherical particles having a size of 1 to 10 μm were observed. A cross section of the particle was cut out by focused ion beam (FIB) processing. Subsequently, when the cross-sectional shape was observed using a transmission electron microscope (TEM / H-7650 manufactured by Hitachi, Ltd.) at 200 kV, the pores of 10-20 nm exhibited a cubic phase structure and were arranged. I understood it. As a result of calculating the total pore volume from the nitrogen adsorption / desorption measurement of the silica porous particles (S-1), the peak of the pore size distribution was 12.3 nm, the peak of the distribution of the connecting pores was 3.7 nm, and the specific surface area was 697 m ² / g, Total pore volume 1.15 ml / g, The porosity determined from the total pore volume was 71.7%. (Bulk density: 1 / (1.15 / 0.717) = 0.623)

<Formation of porous silica particles-2>
(Preparation of polymethacrylic acid ester copolymer / TMOS dehydration condensate solution)
As an aqueous dispersion (acrylic emulsion) of a polymethacrylic ester copolymer, PAN-6 (particle size: 90-130 nm) manufactured by Mitsui Chemicals, Inc. was used.

  15 parts by weight of methanol as a solvent was added to 10 parts by weight of tetramethoxysilane (TMOS) and stirred at room temperature. Further, 2 parts by weight of 1M oxalic acid aqueous solution of the catalyst was added dropwise (to make the pH after addition of the polyolefin end-branched copolymer about 3), and then stirred at room temperature to obtain a dehydrated condensate of TMOS.

  73 parts by weight of PAN-6 (solid content: 10% by weight) was added dropwise to the resulting dehydrated condensate of TMOS and stirred at room temperature to prepare a polymethacrylic acid ester copolymer / TMOS dehydrated condensate solution. . (Polymethacrylate copolymer / silica: SiO2 weight ratio is 65/35)

(Formation of polymethacrylate copolymer / silica composite particles)
This composition is poured into a spray dryer apparatus (spray dryer ADL311S manufactured by Yamato Scientific Co., Ltd.), pressurized at a nozzle outlet temperature of 190 ° C. (0.2 MPa), and sprayed to form a polymethacrylate copolymer / silica. The composite fine particles were obtained.

(Formation of silica porous particles (S-2))
By heating the obtained polymethacrylic acid ester copolymer / silica composite particles from room temperature to 600 ° C. at a rate of 5 ° C. per minute using an electric furnace, and further firing at 600 ° C. for 2 hours. The polymethacrylic acid ester copolymer was removed to obtain silica porous particles (S-2). In observation by SEM, spherical particles of 1 to 10 μm were observed. Observation of the cross section of the particles by TEM revealed that pores of 100 to 150 nm had a cubic phase structure and were arranged. The peak of the pore size distribution determined from the nitrogen adsorption measurement is 143 nm, the distribution peak of the total pore volume connected pore is 44 nm, the specific surface area is 88 m ² / g, the total pore volume is 1.21 ml / g, and the porosity is It was 72.6%. (Bulk density: 1 / (1.21 / 0.726) = 0.6)

<Formation of porous silica particles-3>
(Preparation of surfactant Pluronic P123 / TEOS dehydration condensate solution)
1.2 parts by weight of ethanol as a solvent was added to 1.04 parts by weight of tetraethoxysilane (TEOS) and stirred at room temperature. Further, 0.54 part by weight of 0.01N hydrochloric acid aqueous solution of the catalyst was added dropwise, followed by stirring at 20 ° C. for 20 minutes to obtain a dehydrated condensate of TEOS. Further, separately, a solution prepared by dissolving 0.275 parts by weight of Pluronic P123 in 0.8 parts by weight of ethanol was added dropwise and stirred at room temperature to prepare a P123 / TEOS dehydrated condensate solution.

(Formation of surfactant Pluronic P123 / silica composite particles)
This composition is poured into a spray dryer apparatus (spray dryer ADL311S manufactured by Yamato Scientific Co., Ltd.), pressurized at a nozzle outlet temperature of 190 ° C. (0.2 MPa), and sprayed to obtain composite particles of surfactant Pluronic P123 / silica. Obtained.

(Formation of silica porous particles (S-3))
The obtained Pluronic P123 / silica composite particles were heated from room temperature to 600 ° C. at a rate of 5 ° C. per minute using an electric furnace, and further fired at 600 ° C. for 2 hours to remove the surfactant Pluronic P123. Thus, porous silica particles (S-3) were obtained. In observation by SEM, spherical particles of 1 to 15 μm were observed. When the cross section of the particle was observed by TEM, it was found that 4 nm pores had a hexagonal phase structure and were arranged. The peak of the pore size distribution determined from the nitrogen adsorption measurement was 4 nm, the specific surface area was 825 m ² / g, the total pore volume was 1.07 ml / g, and the porosity was 70.0%. (Bulk density: 1 / (1.07 / 0.70) = 0.65)

<Formation of porous silica particles-4>
(Preparation of polyolefin end-branched copolymer / TMOS dehydrated condensate solution)
15 parts by weight of methanol as a solvent was added to 34.3 parts by weight of tetramethoxysilane (TMOS) and stirred at room temperature. Further, 2 parts by weight of 1M oxalic acid aqueous solution of the catalyst was added dropwise (to make the pH after addition of the polyolefin end-branched copolymer about 3), and then stirred at room temperature to obtain a dehydrated condensate of TMOS.

  To the resulting dehydrated condensate of TMOS, 73 parts by weight of an aqueous dispersion of polyolefin-based terminally branched copolymer (T) (solid content 10% by weight) was added dropwise and stirred at room temperature. A polymer / TMOS dehydrated condensate solution was prepared. (Polyolefin end-branched copolymer / silica: SiO2 weight ratio is 35/65)

(Formation of polyolefin end-branched copolymer / silica composite particles)
This composition was poured into a spray dryer apparatus (spray dryer ADL311S manufactured by Yamato Scientific Co., Ltd.), pressurized (0.2 MPa) at a nozzle outlet temperature of 190 ° C., and sprayed to obtain a polyolefin end-branched copolymer / silica. Composite fine particles were obtained.

(Formation of silica porous particles (S-4))
The polyolefin end-branched copolymer / silica composite particles obtained were heated at a rate of 5 ° C. per minute from room temperature to 600 ° C. using an electric furnace, and further baked at 600 ° C. for 2 hours. The system terminal branched copolymer was removed to obtain porous silica particles (S-4). The particle diameter was observed using a scanning electron microscope (JSM-6701F type manufactured by SEM / JEOL) under the condition of 1.5 kV. As a result, spherical particles having a size of 1 to 10 μm were observed. A cross section of the particle was cut out by focused ion beam (FIB) processing. Subsequently, when the cross-sectional shape was observed using a transmission electron microscope (TEM / H-7650 manufactured by Hitachi, Ltd.) at 200 kV, the pores of 10-20 nm exhibited a cubic phase structure and were arranged. I understood it. As a result of calculating the total pore volume from the nitrogen adsorption / desorption measurement of the silica porous particles (S-4), the pore size distribution peak was 12.2 nm, the connection pore distribution peak was 3.7 nm, and the specific surface area was 200 m ² / g, Total pore volume 0.4 ml / g, The porosity determined from the total pore volume was 46.8%. (Bulk density: 1 / (0.4 / 0.468) = 1.17)

In the formation of (S-1) to (S-4), the nitrogen adsorption / desorption measurement was performed as follows.
Autosorb 3 (manufactured by Cantachrome) was used, and measurement was performed by a nitrogen gas adsorption method at a liquid nitrogen temperature (77K).
The characteristics of the silica porous particles and Aerosil OX-50 are shown in Table 1.

Evaluation test
[Volume shrinkage test]
After filling the cell with the dental composition, the cell was heated at 90 ° C. for 2 hours to thermally cure the dental composition. The density (D1) of the dental composition after thermosetting was measured using a gas displacement pycnometer (manufactured by Shimadzu Corporation: Accupic II).

  Subsequently, using a dental light irradiator (JETLITE 3000), the heat-cured dental composition was irradiated with light for 30 seconds to be photopolymerized. The density (D2) of the dental composition after photopolymerization was measured using a gas displacement pycnometer (manufactured by Shimadzu Corporation: Accupic II).

From the density (D1) of the obtained dental composition after thermosetting and the density (D2) of the dental composition after photopolymerization, the shrinkage ratio of the dental composition was calculated based on the following formula.
Shrinkage (%) = {(density after curing D2−density before curing D1) / density after curing D2)} × 100

(Reference Example 1)
Bisphenol A diglycidyl ether methacrylic acid adduct (Bis-GMA) and triethylene glycol dimethacrylate (3G) were mixed at a weight ratio of 60:40. A composition (paste) was prepared by adding 0.3% by weight of camphor-quinone (CQ) and butoxyethyl N, N-dimethylaminobenzoate to the resulting mixture (Bis-GMA / 3G). The density of the composition and the density of the cured product were measured in the same manner as in Example 1, and the shrinkage rate was calculated.

Example 1
Bisphenol A diglycidyl ether methacrylic acid adduct (Bis-GMA) and triethylene glycol dimethacrylate (3G) were mixed at a weight ratio of 60:40. 0.658 g of the obtained mixture (Bis-GMA / 3G), 0.296 g of silica porous particles (S-1) obtained in the formation of metal oxide porous particles-1 and silica filler (Aerosil OX-) 50 EVONIC) (0.046 g) was mixed and camphor-quinone (CQ) and butoxyethyl N, N-dimethylaminobenzoate were each added at 0.3% by weight to prepare a composition (paste). The density was measured at room temperature using a density measuring device (Gas Pycnometer Accupic II 1340). Next, the composition is placed in a silicon sheet having a cylindrical mold having a diameter of 10 mm and a height of 5 mm placed on a glass plate, and a cellophane film is placed on the top, and a dental light irradiation device (Jetlight 3000 Morita) is used 1 minute from the upper surface and 30 seconds from the lower surface. The density of the obtained cured product was measured using the above-described density measuring apparatus, and the shrinkage rate was calculated.

(Examples 2 to 4)
A composition was prepared in the same manner as in Example 1 except that the blending ratio of the mixture (Bis-GMA / 3G), silica porous particles (S-1), and silica filler was changed as shown in Table 1, and the density was measured. Then, a cured product was formed, the density of the composition and the density of the cured product were measured, and the shrinkage rate was calculated.

(Example 5)
The density of the composition and the density of the cured product were changed in the same manner as in Example 1 except that the silica porous particles were changed to the silica porous particles (S-2) obtained in Formation of metal oxide porous particles-1. The shrinkage was measured and calculated.

(Comparative Example 1)
0.658 g of the mixture (Bis-GMA / 3G), 0.296 g of silica porous particles (S-3) obtained in the formation of metal oxide porous particles-3, silica filler (Aerosil OX-50 EVONIC) 0.046 g was mixed, 0.003 g of camphor-quinone (CQ) and butoxyethyl N, N-dimethylaminobenzoate were added to prepare a composition (paste), and the same method as in Example 1 was used. The density of the composition and the density of the cured product were measured, and the shrinkage rate was calculated.

(Comparative Example 2)
0.658 g of the mixture (Bis-GMA / 3G), 0.296 g of the silica porous particles (S-4) obtained in Formation of metal oxide porous particles-4, silica filler (Aerosil OX-50 EVONIC) 0.046 g was mixed, 0.003 g of camphor-quinone (CQ) and butoxyethyl N, N-dimethylaminobenzoate were added to prepare a composition (paste), and the same method as in Example 1 was used. The density of the composition and the density of the cured product were measured, and the shrinkage rate was calculated.

(Reference Example 2)
A composition (paste) was prepared by adding 0.3% by weight of camphor-quinone (CQ) and butoxyethyl N, N-dimethylaminobenzoate to 3G only to 3G, and in the same manner as in Example 1. The density of the composition and the density of the cured product were measured, and the shrinkage rate was calculated.

(Example 6)
The density of the composition was the same as in Example 1 except that 3G was changed to 0.700 g, and the silica porous particles (S-1) obtained in the formation of metal oxide porous particles-1 were changed to 0.300 g. The density of the cured product was measured and the shrinkage was calculated.

(Comparative Example 3)
The density and curing of the composition were the same as in Example 1 except that the porous silica particles were not mixed, and 0.73 g of (3G) and 0.300 g of silica filler (Aerosil OX-50 EVONIC) were used. The density of the object was measured and the shrinkage rate was calculated.
As shown in Table 2, it was found that when silica porous particles were blended, a low shrinkage was exhibited. In the state where the silica porous particles are in a paste state, the photopolymerizable monomer is filled in the pores of the metal oxide porous particles, and it is verified whether they function as a host guest compound to be released during polymerization. A description will be given based on the values measured in Example 1.

  First, in Example 1, the photopolymerizable monomer (Bis-GMA / 3G), the porous silica particles (S-1), the silica filler, and the photopolymerization initiator were mixed. The movement will be described.

  Volume before curing of composition (actual value) = 1 g / 1.229 (density before curing: D1) = 0.814 ml. Volume of photopolymerizable monomer only = 0.658 g / 1.128 (density of photopolymerizable monomer) = 0.580 ml. On the other hand, theoretically, the volume of silica porous particles (S-1) alone = 0.296 g / 0.623 (bulk density of S-1) = 0.475 ml. Volume of silica filler = 0.046 g / 2.206 (density of silica filler) = 0.021 ml. Therefore, the volume before curing of the composition (theoretical value) = 0.580 + 0.475 + 0.021 = 1.076 ml. There is a difference of 0.814−1.076 = −0.262 ml between the theoretical value and the actual measured value (VB1−VB2) of the composition before curing. Incidentally, the volume of the pores of the silica porous particles (S-1) is 0.475 ml × 0.717 (porosity) = 0.337 ml. From this, it can be inferred that 0.262 ml of the photopolymerizable monomer penetrates into the S-1 pores during mixing.

Next, the movement of the photopolymerizable monomer during the photopolymerization of the composition will be described.
The volume after photocuring of the composition (actual measured value) = 1 g / 1.2612 (density after curing: D2) = 0.793 ml. On the other hand, only the photopolymerizable monomer is related to the shrinkage, so theoretically the volume after photopolymerization (theoretical value) = (0.580-0.262) x (1-1 x 0.0813) (photopolymerization) Shrinkage rate of the functional monomer: 8.13% Reference Example 1) = 0.292 ml. Therefore, the volume is calculated as 0.292 + 0.475 + 0.021 = 0.788ml.

  There is a difference of 0.005 ml between the theoretical value of the volume after curing and the actually measured value (VA1-VA2), and this difference is due to the release of the photopolymerizable monomer from the S-1 holes during the photopolymerization. I can guess it.

The values obtained in the same manner as in Example 1 for Examples 2 to 6 and Comparative Examples 1 and 2 are listed in Table 2.
From these, it is clear that when silica porous particles (S-1) and (S-2) are added, they act as host guest compounds. On the other hand, when the silica porous particles (S-3) and (S-4) were added, the action of the host guest was not observed. This is presumed to be related to the small pore diameter, the small porosity, and the pore structure.

In Table 1,-indicates that measurement is not possible because the pores are too small or absent.

Claims (8)

It contains a polymerizable monomer (A), metal oxide porous particles (B), and a polymerization initiator and / or sensitizer (C), and the metal oxide porous particles (B) have an average pore diameter. A dental curable composition having a surface area of 10 to 300 nm, a specific surface area of 80 m ² / g or more, and a porosity of 50% by volume or more. The dental curable composition according to claim 1, wherein the pore structure of the metal oxide porous particles (B) is a cubic phase structure, and the pores are connected with a pore diameter of 3 nm or more. object. The dental curable composition according to claim 1 or 2, wherein the metal oxide porous particles (B) contain a metal selected from the group consisting of silicon, titanium, zirconium, yttrium, and aluminum. object. The polymerizable monomer (A) is a radical photopolymerizable substance, and the polymerization initiator and / or sensitizer is a photopolymerization initiator and / or a photosensitizer. The dental curable composition according to any one of 3 above. 5 to 80% by weight of metal oxide particles (B) and 0.001 to 10% by weight of a polymerization initiator and / or a sensitizer (C) are contained with respect to the photopolymerizable monomer (A). The dental curable composition according to claim 1, wherein the dental curable composition is a dental curable composition. The dental curable composition according to any one of claims 1 to 5, further comprising an amine compound as a photopolymerization accelerator. Furthermore, it contains at least one filler selected from the group consisting of inorganic particles other than the metal oxide porous particles (B), organic particles, and organic-inorganic composite particles. The dental curable composition as described. Hardened | cured material obtained by superposing | polymerizing the dental composition in any one of Claims 1-7.