JP2021147386A - Photopolymerization initiator comprising aryl iodonium salt for dental photocurable composition - Google Patents

Abstract

To provide a photopolymerization initiator that exhibits excellent sensitivity to photopolymerization and can secure a sufficient pot life for ambient light, and a dental photocurable composition comprising the photopolymerization initiator.SOLUTION: A photopolymerization initiator and a dental photocurable composition are provided. (c) The photopolymerization initiator used in a dental photocurable composition comprises, (c-1) a photosensitizer, (c-2) polymerization accelerator, and (c-3) an aryliodonium salt represented by Formula (1). In the formula, R1 represents an organic group bonded to I, R2 represents an alkyl group in which one or more of hydrogen atoms is replaced with a fluorine atom, and b indicates the number thereof, which is an integer of 1 to 5.SELECTED DRAWING: None

Description

The present invention relates to dental photocurable compositions and photopolymerization initiators used in dental photocurable compositions.

In the dental field, dental photocurable compositions are used for treatment of the oral cavity, such as dental adhesives, dental composite resins, dental abutment construction materials, dental resin cements, and dental surface coatings. It is applied to materials, dental pit fissure sealing materials, dental manicure materials, etc.

Japanese Patent No. 4093974 Japanese Patent No. 4596786

However, sufficient physical properties could not be obtained with the photopolymerization initiator used in the dental photocurable composition.

Patent Documents 1 and 2 propose photopolymerization initiators containing a photoacid generator (triazine compound or a specific aryliodonium salt), a sensitizer, and an electron donor compound as photopolymerization initiators. However, it was not possible to obtain sufficient physical properties.

There is a demand for a photopolymerization initiator that exhibits excellent sensitivity to photopolymerization and can secure a sufficient pot life with respect to ambient light, and has dental photocurability containing the photopolymerization initiator. The purpose is to provide the composition.

The present invention relates to (c) a photopolymerization initiator used in a dental photocurable composition.
(C-1) Photosensitizer, (c-2) Polymerization accelerator, and (c-3) formula (1):

（式中、Ｒ１はＩに結合している有機基を示し、Ｒ２は水素原子の一部がフッ素原子で置換されたアルキル基を表し、ｂはその個数を示し、１〜５の整数である）で表されるアリールヨードニウム塩
を含む光重合開始剤である。

(In the formula, R1 represents an organic group bonded to I, R2 represents an alkyl group in which a part of a hydrogen atom is substituted with a fluorine atom, and b represents the number thereof, which is an integer of 1 to 5. ) Is a photopolymerization initiator containing an aryliodonium salt.

The photopolymerization initiator of the present invention makes it possible to obtain a dental photocurable composition which exhibits excellent sensitivity to irradiation light and secures a sufficient pot life with respect to ambient light. In addition, the dental photocurable composition containing the photopolymerization initiator of the present invention has excellent bending strength.

In the above-mentioned (c) photopolymerization initiator of the present invention, the formula (1) of (c-3) is that R2 is an aryliodonium salt which is an alkyl group in which 80% or more of hydrogen atoms are substituted with fluorine atoms. May be good.

It may be a dental photocurable composition containing the (c) photopolymerization initiator and (a) polymerizable monomer.
It may be a dental photocurable composition containing (c) a photopolymerization initiator, (a) a polymerizable monomer, and (b) a filler.

(A) Photosensitizer: 0.1 to 5 parts by mass, (c-2) Polymerization accelerator: 0.01 to 10 parts by mass, based on 100 parts by mass of the polymerizable monomer. And an aryliodonium salt represented by the formula (1) (c-3): a dental photocurable composition containing 0.01 to 10 parts by mass of the photopolymerization initiator (c).
(A) The filler may be a dental photocurable composition containing 10 to 1900 parts by weight with respect to 100 parts by mass of the polymerizable monomer.

Dental photocurable composition, which is a dental adhesive, a dental composite resin, a dental abutment construction material, a dental resin cement, a dental surface covering material, a dental pit fissure sealing material, and a dental manicure material. It may be.

Hereinafter, each component in the dental photocurable composition of the present invention will be described in detail.
The present invention relates to a photopolymerization initiator and a dental photocurable composition containing the photopolymerization initiator. The dental photocurable composition of the present invention is a dental adhesive, a dental composite resin, a dental abutment construction material, a dental resin cement, a dental surface covering material, a dental pit fissure sealing material, and a dental. It is applied as a manicure material.

In dental clinics, in order to perform aesthetic and functional recovery for tooth defects caused by caries and fractures, after pretreatment with dental adhesives, direct restoration with dental composite resin and ceramics Treatment is performed by indirect restoration, in which a prosthetic device made of hard resin is attached using dental resin cement. Dental composite resins and dental resin cements are made by mixing various fillers such as resin matrix composed of several kinds of polymerizable monomers, inorganic fillers and organic-inorganic composite fillers, and polymerization initiators to form a uniform paste. Prepared. The composite resin for dental filling is filled in the tooth in the state of an uncured paste, and after giving the anatomical form of the natural tooth with a dental instrument such as an instrument, light is applied by a dental light irradiator or the like. It is used by irradiating and curing. As the irradiation light from the light irradiator, a light source having an output of about ^{100 to 2000 mW / cm 2} in a wavelength range of about 360 to 500 nm is generally used. On the other hand, dental resin cement is used when the prosthetic device is adhered to the tooth cavity or abutment tooth, and the prosthetic device is attached to the tooth cavity or abutment tooth and then irradiated with light to be cured.

As a photopolymerization initiator for dental composite resins and dental resin cements, a system in which a photosensitizer or a photosensitizer combined with an appropriate photopolymerization accelerator is widely used. Acylphosphine oxide compounds and α-diketone compounds are known as photosensitizers, and in particular, the α-diketone compound has an ability to initiate polymerization in the wavelength range of visible light, which has little effect on the human body. Further, a tertiary amine compound is well known as a polymerization accelerator to be combined with a photosensitizer, and a combination of an α-diketone compound and a tertiary amine compound has high polymerization activity with respect to irradiation light. It is used in the field of dental materials. The dental photocurable composition containing the photopolymerization initiator exhibits excellent mechanical properties such as hardness, bending strength, and compressive strength required for dental filling composite resins and dental resin cements.

However, when the combination of the α-diketone compound and the tertiary amine compound is used as the photopolymerization initiator, there arises a problem that the ambient photostability is poor. That is, the operation is performed under white light (ambient light) such as a dental light that illuminates the oral cavity or an indoor light such as a fluorescent lamp, but only the combination of the α-diketone compound and the tertiary amine compound described above. When is used as a photopolymerization initiator, it exhibits high sensitivity not only to irradiation light but also to ambient light, so that curing gradually progresses during operations such as filling, building, and mounting, and the paste There was a problem that the viscosity of the light increased and the operation became difficult.

When the amount of the photopolymerization initiator added is reduced or the amount of the polymerization inhibitor added is increased in order to solve the above problems, the stability to ambient light is improved, but the sensitivity to irradiation light is also increased at the same time. It will drop. Therefore, even if the irradiated light is irradiated for a long time, sufficient curing does not proceed, the mechanical strength of the cured product is lowered, or a large amount of surface unpolymerized layer remains, so that the oral cavity is colored over time. Causes problems such as causing. As another problem, when a tertiary amine compound is blended as a polymerization accelerator, there is a problem that the cured product is easily discolored when exposed to sunlight or the like. When used as a dental adhesive, there are problems that the adhesive strength decreases when a heat load is applied assuming the oral cavity, and that the adhesive layer after curing is discolored. As described above, it has been difficult to coexist each property such as both environmental light stability and high polymerization activity with respect to irradiation light.

As a photopolymerization initiator, a photopolymerization initiator containing a specific aryliodonium salt, a sensitizer and an electron donor compound has been proposed, but sufficient physical properties could not be obtained. Photopolymerization initiators containing aryliodonium salts have the following problems. First, conventional aryliodonium salts have low solubility in polymerizable monomers, and are limited to compounding at extremely low concentrations due to risks such as precipitation, assuming clinical use temperature. Therefore, the photopolymerization activity was insufficient. Furthermore, by using an aryl iodonium salt in combination with a polymerization accelerator such as a tertiary amine compound, the photosensitivity is increased, so that the stability to ambient light is low and the operable time is significantly shortened, and the product is exposed to sunlight. The problem was that the discoloration of the cured product was further promoted.
Although the detailed promoting mechanism for discoloration is unknown, the discoloration occurs when the cation portion contained in the structure of the photoacid generator and the polymerization accelerator such as a tertiary amine compound or an organometallic compound forms a salt or interacts with each other. Is presumed to be promoted.

However, according to the studies by the present inventors, when a photopolymerization initiator containing an aryliodonium salt having a specific structure is used in the dental photocurable composition, the solubility in a polymerizable monomer is used. The present invention has been completed by finding that there is no risk of precipitation and the like, moderate photosensitivity is exhibited, and discoloration when exposed to sunlight or the like is significantly reduced.

As described above, it exhibits high polymerization activity with respect to irradiation light, and when applied to, for example, dental filling composite resin or dental resin cement, it has aesthetic and mechanical properties (hardness, bending strength, compressive strength, etc.). ), And when applied as an adhesive, it provides a dental photocurable composition that has durable adhesive strength, is excellent in long-term storage stability, environmental light stability, and is also excellent in color tone stability.

<(A) Polymerizable monomer>
The (a) polymerizable monomer that can be used in the present invention can be used without any limitation from among known monofunctional and / or polyfunctional polymerizable monomers generally used in the dental field. can do. To give an example of a representative one generally preferably used, it is a (meth) acrylate monomer or a (meth) acryloyl polymerizable monomer having an acryloyl group and / or a methacryloyl group. In the present invention, both the acryloyl group-containing polymerizable monomer and the methacryloyl group-containing polymerizable monomer are comprehensively referred to as (meth) acrylate or (meth) acryloyl.

Specific examples of the (meth) acrylate-polymerizable monomer that can be used as the (a) polymerizable monomer are as follows.
Examples of the monofunctional monomer include methyl (meth) acrylate, ethyl (meth) acrylate, butyl (meth) acrylate (n-butyl (meth) acrylate, i-butyl (meth) acrylate), and hexyl (meth) acrylate. Dicyclopentenyl (meth) acrylate, tetrahydrofurfuryl (meth) acrylate, 2-hydroxyethyl (meth) acrylate, glycidyl (meth) acrylate, lauryl (meth) acrylate, cyclohexyl (meth) acrylate, benzyl (meth) acrylate, allyl (Meta) acrylic acid esters such as (meth) acrylate, 2-ethoxyethyl (meth) acrylate, methoxypolyethylene glycol (meth) acrylate, glycerol (meth) acrylate, isobonyl (meth) acrylate, γ- (meth) acryloyloxy Silane compounds such as propyltrimethoxysilane and γ- (meth) acryloyloxypropyltriethoxysilane, 2- (N, N-dimethylamino) ethyl (meth) acrylate, N-methylol (meth) acrylamide, diacetone (meth) Examples thereof include nitrogen-containing compounds such as acrylamide.

Examples of the aromatic bifunctional monomer include 2,2-bis (4- (meth) acryloyloxyphenyl) propane and 2,2-bis (4- (3- (meth) acryloyloxy-2-hydroxypropoxy). ) Phenyl) propane, 2,2-bis (4- (meth) acryloyloxyethoxyphenyl) propane, 2,2-bis (4- (meth) acryloyloxydiethoxyphenyl) propane, 2,2-bis (4-) (Meta) acryloyloxytetraethoxyphenyl) propane, 2,2-bis (4- (meth) acryloyloxypentaethoxyphenyl) propane, 2,2-bis (4- (meth) acryloyloxydipropoxyphenyl) propane, 2 (4- (Meta) acryloyloxyethoxyphenyl) -2 (4- (meth) acryloyloxydiethoxyphenyl) propane, 2 (4- (meth) acryloyloxydiethoxyphenyl) -2 (4- (meth) acryloyloxy) Triethoxyphenyl) propane, 2 (4- (meth) acryloyloxydipropoxyphenyl) -2 (4- (meth) acryloyloxytriethoxyphenyl) propane, 2,2-bis (4- (meth) acryloyloxydipropoxy) Phenyl) propane, 2,2-bis (4- (meth) acryloyloxyisopropoxyphenyl) propane and the like can be mentioned.

Examples of the aliphatic bifunctional monomer include 2-hydroxy-3-acryloyloxypropyl methacrylate, neopentyl glycol di (meth) acrylate of hydroxypivalate, ethylene glycol di (meth) acrylate, and diethylene glycol di (meth) acrylate. Triethylene glycol di (meth) acrylate, butylene glycol di (meth) acrylate, neopentyl glycol di (meth) acrylate, propylene glycol di (meth) acrylate, polyethylene glycol di (meth) acrylate, 1,3-butanediol di ( Examples thereof include meta) acrylate, 1,4-butanediol di (meth) acrylate, 1,6-hexanediol di (meth) acrylate, and glycerol di (meth) acrylate.

Examples of the trifunctional monomer include trimethylolpropane tri (meth) acrylate, trimethylolethanetri (meth) acrylate, trimethylolmethane tri (meth) acrylate, and pentaerythritol tri (meth) acrylate.

Examples of the tetrafunctional monomer include pentaerythritol tetra (meth) acrylate and ditrimethylolpropane tetra (meth) acrylate.

As the urethane-based polymerizable monomer, a polymerizable single amount having a hydroxyl group such as 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, and 3-chloro-2-hydroxypropyl (meth) acrylate. Derived from adducts from the body and diisocyanate compounds such as methylcyclohexane diisocyanate, methylenebis (4-cyclohexylisocyanate), hexamethylene diisocyanate, trimethylhexamethylene diisocyanate, isophorone diisocyanate, diisocyanate methylmethylbenzene, 4,4-diphenylmethane diisocyanate. Examples thereof include di (meth) acrylate having a bifunctional or trifunctional or higher urethane bond.

In addition to these (meth) acrylate-polymerizable monomers, there is no limitation even if an oligomer or prepolymer having at least one or more polymerizable groups in the molecule is used. Further, there is no problem even if a substituent such as a fluoro group is contained in the same molecule.
The polymerizable monomers described above can be used not only individually but also in combination of two or more.

The (a) polymerizable monomer contained in the dental photocurable composition of the present invention contains a known acidic group-containing polymerizable monomer in order to impart adhesiveness to a dentin or a prosthetic device. be able to. Specific examples of the acidic group contained in the acidic group-containing polymerizable monomer include a phosphoric acid group, a pyrophosphate group, a phosphonic acid group, a carboxylic acid group, a sulfonic acid group, a thiophosphate group, and the like. It refers to a polymerizable monomer having one, preferably 10-methacryloyloxydecyldihydrogen phosphate, or 6-methacryloxyhexylphosphonoacetate or 4-methacryloxyethyl trimellitic acid. From the viewpoint of imparting adhesiveness, the blending amount may be 5 to 60 parts by weight, more preferably 10 to 50 parts by weight, out of 100 parts by weight of the total amount of the polymerizable monomer in the composition.

The dental photocurable composition of the present invention may contain a silane coupling material in order to impart adhesiveness to glass ceramics. Any known silane coupling material can be used without limitation, but 3-methacryloxypropyltrimethoxysilane may be used. From the viewpoint of imparting adhesiveness, the blending amount may be 0.5 to 10 parts by weight out of 100 parts by weight of the total amount of the polymerizable monomer in the composition, for example, 0.5 to 5 parts by weight. good.

<(B) Filler>
As the filler (b) that can be used in the present invention, any known filler that is generally used for dental composite materials can be used.

(B) Examples of the type of filler include inorganic fillers, organic fillers, and organic-inorganic composite fillers, which are used not only individually but also in combination of a plurality of fillers regardless of the type of filler. be able to.

The filler is not particularly limited, and examples thereof include silica glass, fluoroaluminosilicate glass, fluoroaluminoborosilicate glass, other silicate glass, and zirconium silicate glass containing zirconia, and zirconium silicate may be used.

The above-mentioned filler (b) is used as a silane coupling material for the purpose of improving the affinity with the polymerizable monomer, the dispersibility in the polymerizable monomer, the mechanical strength of the cured product, and the water resistance. It can be treated with a typical surface treatment material. The surface treatment material and the surface treatment method are not particularly limited, and known methods can be adopted without limitation. Silane coupling materials used for surface treatment of fillers include methyltrimethoxysilane, methyltriethoxysilane, methyltrichlorosilane, dimethyldichlorosilane, trimethylchlorosilane, vinyltrichlorosilane, vinyltriethoxysilane, and vinyltris (β-methoxy). It may be ethoxy) silane, γ-methacryloyloxypropyltrimethoxysilane, γ-chloropropyltrimethoxysilane, γ-glycidoxypropyltrimethoxysilane, hexamethyldisilazane and the like. In addition to the silane coupling material, the surface treatment of the filler can be performed by a method using a titanate-based coupling material or an aluminate-based coupling material. The amount of the filler treated by the surface treatment material is preferably 0.01 to 30 parts by weight, more preferably 0.5 to 20 parts by weight, based on 100 parts by weight of the filler before treatment.

The shape of the filler is not particularly limited, and amorphous and spherical fillers can be used. The average particle size of the filler is preferably 0.01 μm to 50 μm, more preferably 0.1 μm to 30 μm, still more preferably 0.5 μm to 20 μm, and even more preferably 0.5 μm to 10 μm. Has a particle size.

The blending amount of the filler (b) is preferably 10 to 1900 parts by weight, more preferably 30 to 900 parts by weight, and further preferably 100 to 900 parts by weight with respect to 100 parts by mass of the (a) polymerizable monomer. It may be. When more than 1900 parts by weight is blended, the paste properties of the composition are hard and difficult to handle.

<(C) Photopolymerization initiator>
<(C-1) Photosensitizer>
The photosensitizer (c-1) used in the dental photocurable composition of the present invention is not particularly limited, and known compounds generally used in the dental field can be used without any limitation.

Specific examples of photosensitizers include benzyl, camphorquinone, α-naphthyl, acetnaphthene, p, p'-dimethoxybenzyl, p, p'-dichlorobenzylacetyl, pentandione, 1,2-phenanthrenquinone, 1 , 4-Phenantrenquinone, 3,4-Fenantrenquinone, 9,10-Phenantrenquinone, α-diketones such as naphthoquinone, Benzylalkyl ethers such as benzoin, benzoinmethyl ether, benzoin ethyl ether, thioxanthone, 2-chlorothioxanthone. , 2-Methylthioxanthone, 2-isopropylthioxanthone, 2-methoxythioxanthone, 2-hydroxythioxanthone, 2,4-diethylthioxanthone, 2,4-diisopropylthioxanthone and other thioxanthones, benzophenone, p-chlorobenzophenone, p-methoxybenzophenone. Benzophenones such as 2,4,6-trimethylbenzoyldiphenylphosphine oxide, acylphosphine oxides such as bis (2,6-dimethoxybenzoyl) -2,4,4-trimethylpentylphosphine oxide, 2-benzyl -Dimethylamino-1- (4-morpholinophenyl) -butanone-1, 2-benzyl-diethylamino-1- (4-morpholinophenyl) -propanone-1 and other α-aminoacetophenones, benzyl dimethyl ketal, benzyl Ketals such as diethyl ketal and benzyl (2-methoxyethyl ketal), bis (cyclopentadienyl) -bis [2,6-difluoro-3- (1-pyrrolill) phenyl] -titanium, bis (cyclopentadienyl) )-Benz (pentanfluorophenyl) -titanium, bis (cyclopentadienyl) -bis (2,3,5,6-tetrafluoro-4-disyloxyphenyl) -titanium and the like.

The photosensitizer (c-1) used can be appropriately selected depending on the wavelength and intensity of light used for polymerization, the light irradiation time, the type and amount of other components to be combined. In addition, the photosensitizer may be used alone or in combination of two or more. Among them, an α-diketone compound having a maximum absorption wavelength in the visible light region is preferably used, and in particular, camphorquinone may be used.

Usually, the blending amount of (c-1) photosensitizer is preferably 0.01 to 5 parts by weight, more preferably 0.05 to 3 parts by weight, based on 100 parts by weight of the total amount of (a) polymerizable monomer. It may be by weight, more preferably 0.1 to 1 part by weight. When the blending amount of the photosensitizer is less than 0.01 parts by weight, the polymerization activity with respect to the irradiation light is poor and the curing becomes insufficient. When more than 5 parts by weight is blended, although it has sufficient curability, the ambient light stability is shortened and the yellowness is increased.

<(C-2) Polymerization accelerator>
The (c-2) polymerization accelerator used in the dental adhesive composition of the present invention is not particularly limited as long as it has a polymerization promoting ability, and a known polymerization accelerator generally used in the dental field can be used without any limitation. can do. As the polymerization accelerator, an aromatic tertiary amine compound, a tertiary amine compound such as an aliphatic tertiary amine compound, and an organic metal compound can be used.

Specific examples of the above aromatic tertiary amine compounds include N, N-dimethylaniline, N, N-diethylaniline, N, N-di-n-butylaniline, N, N-dibenzylaniline, p. -N, N-dimethyl-toluidine, m-N, N-dimethyl-toluidine, p-N, N-diethyl-toluidine, p-bromo-N, N-dimethylaniline, m-chloro-N, N-dimethylaniline , P-dimethylaminobenzaldehyde, p-dimethylaminoacetophenone, p-dimethylaminobenzoic acid, p-dimethylaminobenzoic acid ethyl ester, p-dimethylaminobenzoic acid amino ester, N, N-dimethylanthranic acid Methyl ester, N, N-dihydroxyethylaniline, p-N, N-dihydroxyethyl-toluidine, p-dimethylaminophenyl alcohol, p-dimethylaminostyrene, N, N-dimethyl-3,5-xylidine, 4-dimethyl Aminopyridine, N, N-dimethyl-α-naphthylamine, N, N-dimethyl-β-naphthylamine and the like can be mentioned. Further, for example, it may be p-N, N-dimethyl-toluidine, or p-N, N-dihydroxyethyl-toluidine.

Specific examples of the above aliphatic tertiary amine compounds include tributylamine, tripropylamine, triethylamine, triethanolamine, N-methyldiethanolamine, N-ethyldiethanolamine, N, N-dimethylhexylamine, N, N. -Dimethyldodecylamine, N, N-dimethylstearylamine, N, N-dimethylaminoethyl methacrylate, N, N-diethylaminoethyl methacrylate, 2- (N, N-diisopropylamino) ethyl methacrylate, 2,2'-(n) -Butyl imino) diethanol, N- [3- (dimethylamino) propyl] acrylamide and the like can be mentioned. Further, for example, it may be N, N-dimethylaminoethyl methacrylate, N, N-diethylaminoethyl methacrylate or triethanolamine.

The above-mentioned organic metal compounds include scandium (Sc), titanium (Ti), vanadium (V), manganese (Mn), iron (Fe), cobalt (Co), nickel (Ni), copper (Cu), and tin (Sn). ), Zinc (Zn), and zirconia (Zr), preferably an organic metal compound containing tin (Sn), vanadium (V), and copper (Cu). Specifically, as organic metal compounds containing tin (Sn), dibutyl-tin-diacetate, dibutyl-tin-dimaleate, dioctyl-tin-dimaleate, dioctyl-tin-dilaurate, dibutyl-tin-dilaurate, dioctyl-tin- Examples thereof include diversate, dioctyl-tin-S, S'-bis-isooctyl mercaptoacetate, tetramethyl-1,3-diacetoxydistanoxane, and examples of the organic metal compound containing vanadium (V) include acetylacetone vanadium and tetra. Divanadium oxide, vanadylacetylacetonate, vanadium stearate oxide, vanadil oxalate, vanadil sulfate, oxobis (1-phenyl-1,3-butandionate) vanadium, bis (maltlate) oxovanadium, vanadium pentoxide, metavanadic acid Examples of organic metal compounds containing copper (Cu) include acetylacetone copper, copper naphthenate, copper octylate, acetylacetone copper stearate, copper naphthenate, copper octylate, copper stearate, and copper acetate. ..

The type of (c-2) polymerization accelerator used can be appropriately selected according to the type and amount of other components to be combined. In addition, the polymerization accelerator may be used alone or in combination of two or more.

Usually, the blending amount of the (c-2) polymerization accelerator is preferably 0.01 to 10 parts by weight, more preferably 0.05 to 5 parts by weight, based on 100 parts by weight of the total amount of the (a) polymerizable monomer. It may be a department. When the blending amount of the polymerization accelerator is less than 0.01 parts by weight, the polymerization promoting ability is poor and curing tends to be insufficient. When more than 10 parts by weight is blended, although it has sufficient curability, the ambient light stability is shortened and the discoloration of the cured product is increased.

<(C-3) aryl iodonium salt>
The aryl iodonium salt (c-3) used in the dental adhesive composition of the present invention is an aryl iodonium salt represented by the formula (1).

式中の［（R1）₂I］^＋のカチオン部分と、［（R2）_bPF_6−b］⁻がアニオン部分から構成される。「式中のＲ１はＩに結合している有機基を示し、Ｒ２は水素原子の一部がフッ素原子で置換されたアルキル基を表し、ｂはその個数を示し、１〜５の整数であるアリールヨードニウム塩」

In the formula, [(R1) ₂ I] ⁺ cation moiety and [(R2) _b PF _6−b ] ⁻ are composed of anion moiety. "R1 in the formula represents an organic group bonded to I, R2 represents an alkyl group in which a part of a hydrogen atom is replaced with a fluorine atom, and b represents the number thereof, which is an integer of 1 to 5. Aryl iodonium salt "

R1 in the formula (1) represents an organic group bonded to I, and R1 may be the same or different. As R1, an aryl group having 6 to 30 carbon atoms, a heterocyclic group having 4 to 30 carbon atoms, an alkyl group having 1 to 30 carbon atoms, an alkenyl group having 2 to 30 carbon atoms, or an alkynyl group having 2 to 30 carbon atoms can be used. These represent alkyl, hydroxy, alkoxy, alkylcarbonyl, arylcarbonyl, alkoxycarbonyl, aryloxycarbonyl, arylthiocarbonyl, acyloxy, arylthio, alkylthio, aryl, heterocycle, aryloxy, alkylsulfinyl, arylsulfinyl, alkylsulfonyl, It may be substituted with at least one selected from the group consisting of arylsulfonyl, alkyleneoxy, amino, cyano, nitro groups and halogens.

In the above, as the aryl group having 6 to 30 carbon atoms, a monocyclic aryl group such as a phenyl group and a condensation of naphthyl, anthrasenyl, phenanthrenyl, pyrenyl, chrysenyl, naphthacenyl, benzanthrasenyl, anthraquinolyl, fluorenyl, naphthoquinone, anthraquinone and the like Polycyclic aryl groups can be mentioned.

Examples of the heterocyclic group having 4 to 30 carbon atoms include cyclic compounds containing 1 to 3 heteroatoms such as oxygen, nitrogen, and sulfur, which may be the same or different, and as a specific example. Is a monocyclic heterocyclic group such as thienyl, furanyl, pyranyl, pyrrolyl, oxazolyl, thiazolyl, pyridyl, pyrimidyl, pyrazinyl and indrill, benzofuranyl, isobenzofuranyl, benzothienyl, isobenzothienyl, quinolyl, isoquinolyl, quinoxalinyl, quinazolinyl. , Carbazolyl, acridinyl, phenothiazine, phenazinyl, xanthenyl, thiantrenyl, phenoxadinyl, phenoxatinyl, chromanyl, isochromanyl, dibenzothienyl, xanthonyl, thioxanthonyl, dibenzofuranyl and the like.

Alkyl groups having 1 to 30 carbon atoms include linear alkyl groups such as methyl, ethyl, propyl, butyl, hexadecyl and octadecyl, isopropyl, isobutyl, sec-butyl, tert-butyl, isopentyl, neopentyl, tert-pentyl and isohexyl. Branched alkyl groups of, cycloalkyl groups such as cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl and the like can be mentioned. The alkenyl group having 2 to 30 carbon atoms includes a linear or branched form such as vinyl, allyl, 1-propenyl, isopropenyl, 1-butenyl, 2-butenyl, 3-butenyl, 1-methyl-1-propenyl and the like. Can be mentioned. Further, as the alkynyl group having 2 to 30 carbon atoms, ethynyl, 1-propynyl, 2-propynyl, 1-butynyl, 2-butynyl, 3-butynyl, 1-methyl-1-propynyl, 1-methyl-2-propynyl Such as linear or branched ones can be mentioned.

The above-mentioned aryl group having 6 to 30 carbon atoms, heterocyclic group having 4 to 30 carbon atoms, alkyl group having 1 to 30 carbon atoms, alkenyl group having 2 to 30 carbon atoms, or alkynyl group having 2 to 30 carbon atoms is at least one. It may have a species substituent, and examples of the substituent include linear alkyl groups having 1 to 18 carbon atoms such as methyl, ethyl, propyl, butyl, octadecyl; isopropyl, isobutyl, sec-butyl, tert-butyl. Branched alkyl groups with 1 to 18 carbon atoms; cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, etc. Cycloalkyl groups with 3 to 18 carbon atoms; hydroxy groups; methoxy, ethoxy, propoxy, isopropoxy, butoxy, isobutoxy, sec-butoxy, etc. Linear or branched alkoxy groups having 1 to 18 carbon atoms such as tert-butoxy and dodecyloxy; carbonyl groups such as acetyl, propionyl, butanoyl, 2-methylpropionyl, heptanoyle, 2-methylbutanoyl, 3-methylbutanoyl and octanoyl. 2 to 18 linear or branched alkylcarbonyl groups; arylcarbonyl groups with 7 to 11 carbon atoms such as benzoyl and naphthoyl; methoxycarbonyl, ethoxycarbonyl, propoxycarbonyl, isopropoxycarbonyl, butoxycarbonyl, isobutoxycarbonyl, sec-butoxy Linear or branched alkoxycarbonyl groups with 2 to 19 carbon atoms such as carbonyl and tert-butoxycarbonyl; aryloxycarbonyl groups with 7 to 11 carbon atoms such as phenoxycarbonyl and naphthoxycarbonyl; carbons such as phenylthiocarbonyl and naphthoxythiocarbonyl Arylthiocarbonyl group of number 7 to 11; linear or branched with 2 to 19 carbon atoms such as acetoxy, ethylcarbonyloxy, propylcarbonyloxy, isobutylcarbonyloxy, sec-butylcarbonyloxy, tert-butylcarbonyloxy, octadecylcarbonyloxy, etc. Achilloxy groups; phenylthio, biphenylylthio, methylphenylthio, chlorophenylthio, bromophenylthio, fluorophenylthio, hydroxyphenylthio, methoxyphenylthio, naphthylthio, 4- [4- (phenylthio) benzoyl] phenylthio, 4-[ 4- (Phenylthio) phenoxy] phenylthio, 4- [4- (phenylthio) phenyl] phenylthio, 4- (phenylthio) phenylthio, 4-benzoylphenylthio, 4-ben Arylthio groups having 6 to 20 carbon atoms such as zoyl-chlorophenylthio, 4-benzoyl-methylthiophenylthio, 4- (methylthiobenzoyl) phenylthio, 4- (p-tert-butylbenzoyl) phenylthio; methylthio, ethylthio, propylthio, tert- Linear or branched alkylthio groups with 1 to 18 carbon atoms such as butylthio, neopentylthio, dodecylthio; aryl groups with 6 to 10 carbon atoms such as phenyl, tolyl, dimethylphenyl, naphthyl; thienyl, furanyl, pyranyl, xanthenyl, chromanyl, Heterocyclic groups with 4 to 20 carbon atoms such as isochromanyl, xanthonyl, thioxanthonyl and dibenzofuranyl; aryloxy groups with 6 to 10 carbon atoms such as phenoxy and naphthyloxy; methylsulfinyl, ethylsulfinyl, propylsulfinyl, tert-pentylsulfinyl and octyl Linear or branched alkylsulfinyl groups with 1 to 18 carbon atoms such as sulfinyl; arylsulfinyl groups with 6 to 10 carbon atoms such as phenylsulfinyl, trillsulfinyl, naphthylsulfinyl; methylsulfonyl, ethylsulfonyl, propylsulfonyl, isopropylsulfonyl, butylsulfonyl , Octylsulfonyl, etc., linear or branched alkylsulfonyl groups with 1 to 18 carbon atoms; phenylsulfonyl, tolylsulfonyl (tosyl group), naphthylsulfonyl, etc., 6 to 10 carbon atoms arylsulfonyl groups; alkyleneoxy groups; cyano groups; Nitro group; Halogen such as fluorine, chlorine, bromine, iodine and the like can be mentioned.

R2 in the formula (1) represents an alkyl group substituted with a fluorine atom, and may have 1 to 4 carbon atoms. Specific examples of alkyl groups include linear alkyl groups such as methyl, ethyl, propyl, butyl, pentyl and octyl; branched alkyl groups such as isopropyl, isobutyl, sec-butyl and tert-butyl; and cyclopropyl, cyclobutyl and cyclopentyl, Examples thereof include cycloalkyl groups such as cyclohexyl, and R2 may be an alkyl group in which 80% or more of hydrogen atoms are substituted with fluorine atoms. Further, R2 may be an alkyl group in which 90% or more of hydrogen atoms are substituted with fluorine atoms. Further, R2 may be an alkyl group in which 100% or more of hydrogen atoms are substituted with fluorine atoms. If the hydrogen atom in the alkyl group is not replaced by a fluorine atom, discoloration occurs after exposure to sunlight or the like.

By blending the aryliodonium salt represented by the formula (1), discoloration after exposure is suppressed and sufficient pot life under ambient light is secured, but this mechanism is bound by the specific theory of the present invention. Although not done, the following is estimated. The introduction of an alkyl group substituted with a fluorine atom increases the hydrophobicity of the aryliodonium salt. This also applies to the excited state, and since the interaction between the excited aryl iodonium salt and the polymerization accelerator is reduced, the aryl iodonium salt itself is excited or is excited by the energy obtained from the photosensitizer. At this time, energy or electron transfer to the polymerization accelerator is suppressed, which is presumed to lead to suppression of discoloration after exposure to sunlight or the like and securing sufficient pot life under ambient light.

Particularly preferable R2 is a linear or branched alkyl group having 1 to 4 carbon atoms and a hydrogen atom in the alkyl group totally substituted with a fluorine atom, and specific examples thereof include CF ₃ , CF ₃ CF ₂ , (CF). _{3) 2 CF, CF 3 CF} 2 CF 2, CF 3 CF 2 CF 2 CF 2, (CF 3) 2 CFCF 2, CF 3 CF 2 (CF 3) CF, include (CF _{3) 3} C.

In the formula (1), the number b of R2 is an integer of 1 to 5, preferably 2 to 4, and particularly preferably 2 or 3. The b R2s may be the same or different.

Specific examples of the preferred anion moiety include [(CF ₃ CF ₂ ) ₃ PF ₃ ] ⁻ , [(CF ₃ CF ₂ CF ₂ ) ₃ PF ₃ ] ⁻ , [((CF ₃ ) ₂ CF) ₃ PF ₃ ] ^−. , [((CF ₃ ) ₂ CF) ₂ PF ₄ ] ⁻ , [((CF ₃ ) ₂ CFCF ₂ ) ₃ PF ₃ ] ⁻ and [((CF ₃ ) ₂ CFCF ₂ ) ₂ PF ₄ ] − ..

The aryliodonium salt represented by the formula (1) has excellent solubility in a polymerizable monomer and an ability to promote polymerization, and is considered to be diphenyliodonium tris (pentafluoroethyl) trifluorophosphate and ditril iodonium tris (pentafluoroethyl). ) Trifluorophosphate, bis (4-dodecylphenyl) iodonium tris (pentafluoroethyl) trifluorophosphate, bis (4-methoxyphenyl) iodonium, (4-octyloxyphenyl) phenyliodonium tris (pentafluoroethyl) trifluorophosphate , Bis (4-decyloxy) Phenyliodonium Tris (Pentafluoroethyl) Trifluorophosphate, 4- (2-Hydroxytetradecyloxy) Phenylphenyl Iodonium Tris (Pentafluoroethyl) Trifluorophosphate, 4-Isopropylphenyl (p-Trill) ) Iodonium tris (pentafluoroethyl) trifluorophosphate, 4-isobutylphenyl (p-tolyl) iodonium tris (pentafluoroethyl) trifluorophosphate, bis (4-tert-butylphenyl) iodonium tris (pentafluoroethyl) trifluoro Phosphate and bis (4-tert-butylphenyl) iodonium tris (pentafluoropropyl) trifluorophosphate may be used.

Generally, the blending amount of the (c-3) aryliodonium salt is preferably 0.01 to 10 parts by weight, more preferably 0.05 to 5 parts by weight, based on 100 parts by weight of the total amount of the (a) polymerizable monomer. It may be, for example, 0.5 to 3 parts by weight. When the blending amount of the aryl iodonium salt is less than 0.01 parts by weight, the polymerization promoting ability is poor and the curing becomes insufficient. When more than 10 parts by weight is blended, although it has sufficient curability, the ambient light stability becomes short and the cured product becomes brownish and discoloration increases.

These photopolymerization initiators can be used alone or in combination of two or more. Further, these polymerization initiators may be subjected to a secondary treatment such as being encapsulated in microcapsules as necessary, and there is no problem. Further, these various types of photopolymerization initiators can be used alone or in combination of two or more, regardless of the polymerization mode or polymerization method.

In the dental photocurable composition of the present invention, a chemical polymerization initiator may be blended in addition to the (c) photopolymerization initiator, and a known chemical polymerization initiator can be used without limitation. As the chemical polymerization initiator, a thiourea derivative, an organic peroxide having a hydroperoxide group, or a sulfinate can be used alone or in combination.

As the thiourea derivative, any known thiourea derivative can be used without limitation. Specific examples of the thiourea derivative include dimethylthiourea, diethylthiourea, tetramethylthiourea, (2-pyridyl) thiourea, N-methylthiourea, ethylenethiourea, N-allylthiourea, and N-allyl-N'-(2-). Hydroxyethyl) thiourea, N-benzyl thiourea, 1,3-dicyclohexylthiourea, N, N'-diphenylthiourea, 1,3-di (p-tolyl) thiourea, 1-methyl-3-phenylthiourea, Examples thereof include N-acetylthiourea, N-benzoylthiourea, diphenylthiourea and dicyclohexylthiourea. Among these, N-acetylthiourea and N-benzoylthiourea may be used. A plurality of types of these thiourea derivatives may be used in combination, if necessary. The blending amount of the thiourea derivative is preferably 0.1 to 4 parts by weight with respect to the total amount of the total polymerizable monomer, and if it is less than 0.1 part by weight, the polymerization promoting ability is insufficient, and if it exceeds 4 parts by weight. Storage stability may be reduced.

As the organic peroxide having a hydroperoxide group, any known organic peroxide having a hydroperoxide group can be used without limitation. Specific examples of organic peroxides include t-butyl hydroperoxide, cyclohexyl hydroperoxide, cumene hydroperoxide, diisopropylbenzene hydroperoxide, p-menthane hydroperoxide, diisopropylbenzene hydroperoxide, 1,1,3,3-tetramethyl. Examples thereof include butyl hydroperoxide, and cumene hydroperoxide may be used from the viewpoint of reactivity. A plurality of types of these organic peroxides may be used in combination, if necessary. The blending amount of the organic peroxide having a hydroperoxide group is preferably 0.1 to 4 parts by weight with respect to the total amount of the total polymerizable monomer, and if it is less than 0.1 part by weight, the ability as a polymerization accelerator is insufficient. If it exceeds 4 parts by weight, the storage stability may decrease.

Examples of the sulfinic acid derivative include p-toluenesulfinic acid, benzenesulfinic acid, 2,4,6-trimethylbenzenesulfinic acid, 2,4,6-triethylbenzenesulfinic acid, 2,4,6-triisopropylbenzenesulfinic acid and the like. Salts (which may be alkali metals or alkaline earth metals) are mentioned, and specific examples of these sulfinic acid salt compounds include sodium p-toluenesulfinate and sodium benzenesulfinate.

<(D) Solvent>
The solvent (d) that can be used in the present invention can be used without any limitation as long as it is a known solvent used in the dental field. Examples of representative ones that are preferably used include water and organic solvents. Among the organic solvents, water-soluble volatile organic solvents having a boiling point of 100 ° C. or less under normal pressure are preferable, and specific examples thereof. Examples include ethanol, methanol, 1-propanol, isopropyl alcohol, acetone, methyl ethyl ketone, 1,2-dimethoxyethane, 1,2-diethoxyethane and tetrahydrofuran, and water, acetone and ethanol are particularly preferable. (D) The blending amount of the solvent may be 1 to 300 parts by weight, for example, 50 to 300 parts by weight, or 100 to 250 parts by weight with respect to the total amount of the total polymerizable monomer.

<Other ingredients>
Further, the dental photocurable composition of the present invention may contain components other than the above-mentioned components (a) to (d) as long as the effects of the present invention are not impaired. For example, excipients typified by fumed silica, benzophenone-based and benzotriazole-based ultraviolet absorbers, hydroquinones, hydroquinone monomethyl ethers, polymerization inhibitors such as 2,5-diterpinene butyl-4-methylphenol, α- Alkylstyrene compounds, mercaptan compounds such as n-butyl mercaptan, n-octyl mercaptan, terpinene compounds such as limonene, milsen, α-terpinene, β-terpinene, γ-terpinene, terpinene, β-pinene, α-pinene, etc. Chain transfer materials, metal supplements such as aminocarboxylic acid-based chelating agents and phosphonic acid-based chelating agents, discoloration inhibitors, antibacterial materials, coloring pigments, water and solvents that can be mixed with water in any ratio, and others. Ingredients such as conventionally known additives can be arbitrarily added as needed.

The method for preparing the dental photocurable composition of the present invention is not particularly limited. As a general method for producing a dental photocurable composition, a binder resin in which (a) a polymerizable monomer and (c) a photopolymerization initiator is mixed in advance is prepared, and then the binder resin and (b) are filled. A method of kneading the materials and removing air bubbles under vacuum to prepare a uniform paste-like composition, or mixing (a) a polymerizable monomer with (c) a photopolymerization initiator and (d) a solvent. Examples thereof include a method of preparing a homogeneous liquid composition. Also in the present invention, it can be produced by the above-mentioned production method without any problem.

In the dental field, dental photocurable compositions are used for treatment of the oral cavity, such as dental adhesives, dental composite resins, dental abutment construction materials, dental resin cements, and dental surface coatings. Since it is applied to materials, dental pit fissure sealing materials, dental manicure materials, etc., it has potential for industrial use.

Examples of the present invention will be specifically described below, but the present invention is not limited to these examples.

The materials used in Examples and Comparative Examples and their abbreviations are shown below.
[(A) Polymerizable monomer]
-Bis-GMA: 2,2-bis [4- (3-methacryloyloxy-2-hydroxypropoxy) phenyl] propane-2.6E: 2,2-bis having an average addition molar number of 2.6 ethoxy groups (4- (Meta) acryloyloxypolyethoxyphenyl) propane ・ UDMA: N, N- (2,2,4-trimethylhexamethylene) bis [2- (aminocarboxy) ethanol] methacrylate ・ TEGDMA: Triethylene glycol dimethacrylate -GDMA: glycerol dimethacrylate-2-HEMA: 2-hydroxyethyl methacrylate-MDP: 10-methacryloyloxydecyldihydrogen phosphate-6-MHPA: 6-methacryloxyhexylphosphonoacetate-4-MET: 4-methacry Loxyethyl trimellitic acid

[(C) Polymerization Initiator]
(C-1) Photosensitizer ・ CQ: α-camphorquinone

(C-2) Polymerization Accelerator Aromatic Tertiary Amine Compound DMBE: N, N-Dimethylaminoethyl benzoate Aliphatic Tertiary Amine Compound DMAEMA: N, N-dimethylaminoethyl methacrylate Organic Metal Compound SnL : Dioctyl-tin-dilaurate

(C-3) Diaryliodonium salt ・ IPIFP: 4-isopropylphenyl (p-tolyl) iodonium tris (pentafluoroethyl) trifluorophosphate

・ｔＢＩＦＰ： ビス（４−tert−ブチルフェニル）ヨードニウムトリス（ペンタフルオロプロピル）トリフルオロホスフェート

TBIFP: Bis (4-tert-butylphenyl) iodonium tris (pentafluoropropyl) trifluorophosphate

・ＤＰＩＨＰ： ジフェニルヨードニウムヘキサフルオロホスフェート

-DPIHP: Diphenyliodonium hexafluorophosphate

(D) Solvent ・ Water ・ Acetone

[(B) Filler]
The method for producing each filler used in the preparation of the dental photocurable composition is shown below.

50.0 g of water, 35.0 g of ethanol, and 3-methacryloyloxypropyltrimethoxysilane 3 as a silane coupling material with respect to 100.0 g of a zirconium silicate filler (average particle size 2.2 μm: zirconia 90 wt%, silica 10 wt%). .0 g was stirred at room temperature for 2 hours, the obtained silane coupling treatment liquid was added, and the mixture was stirred and mixed for 30 minutes. Then, heat treatment was performed at 140 ° C. for 15 hours to obtain a filler 1.

50.0 g of water, 35.0 g of ethanol, and 3-methacryloyloxypropyltrimethoxysilane 5 as a silane coupling material with respect to 100.0 g of a zirconium silicate filler (average particle size 0.8 μm: zirconia 85 wt%, silica 15 wt%). .0 g was stirred at room temperature for 2 hours, the obtained silane coupling treatment liquid was added, and the mixture was stirred and mixed for 30 minutes. Then, the heat treatment was performed at 140 ° C. for 15 hours to obtain a filler 2.

Chemical polymerization initiator Thiourea derivative ・ BTU: N-benzoylthiourea Organic peroxide having a hydroperoxide group ・ CHP: Cumene hydroperoxide

UV absorber ・ BT: 2- (2-hydroxy-5-methylphenyl) benzotriazole polymerization inhibitor ・ BHT: 2,6-di-t-butyl-4-methylphenol

<Manufacturing method of dental photocurable composition (composite resin for dental filling)>
The polymerizable monomer (a) shown in Table 1, the polymerization initiator (c), and others were mixed using a mix rotor VMRC-5 at 100 rpm for 24 hours to obtain a binder resin in which each material was uniformly dissolved. Obtained. Then, the binder resin and the filler (b) were put into a kneader, stirred uniformly, and then defoamed under vacuum to obtain the dental photocurable compositions of Examples 1 to 12 and Comparative Examples 1 and 2. Prepared.

<Manufacturing method of dental photocurable composition (dental resin cement)>
The polymerizable monomer (a) shown in Table 2, the polymerization initiator (c), and others were mixed using a mix rotor VMRC-5 at 100 rpm for 24 hours to obtain a binder resin in which each material was uniformly dissolved. Obtained. Then, the binder resin and the filler (b) were put into a kneader, stirred uniformly, defoamed under vacuum to obtain pastes 1 and 2, and then filled in a double syringe (5 mL) manufactured by Mixpack. The dental photocurable compositions of Examples 13 to 22 and Comparative Examples 3 to 4 were prepared.

<Manufacturing method of dental photocurable composition>
Example 23 in which the polymerizable monomer (a) shown in Table 3, the polymerization initiator (c), and others were mixed using a mix rotor VMRC-5 at 100 rpm for 24 hours, and each material was uniformly dissolved. The dental photocurable compositions of ~ 28 and Comparative Examples 5-8 were prepared.

<Manufacturing method of dental photocurable composition (dental adhesive)>
(A) Polymerizable monomer shown in Table 4, (c) Photopolymerization initiator and (d) solvent are mixed using a bubbler mixer T2F (Symmal Enterprises), and a homogeneous liquid dental light is used. The curable composition was prepared and filled in a light-shielding plastic container to prepare the dental photocurable compositions of Examples 29 to 36 and Comparative Examples 9 to 10.

The test methods adopted in the examples and comparative examples are as follows. The composite resin for dental filling and the dental resin composition were directly collected, and the dental resin cement was a paste obtained by mixing pastes 1 and 2 using a mixing tip manufactured by Mixpack.

(1) Bending strength After filling the prepared dental photocurable composition in a stainless steel mold, placing cover glasses on both sides and pressing with a glass kneading plate, a photopolymerization irradiator (Blue Shot: made by Matsukaze) It was cured by irradiating light at 5 places for 10 seconds each. After curing, the cured product was taken out from the mold, and then the back surface was also irradiated with light in the same manner, and this was used as a test body (25 × 2 × 2 mm: rectangular parallelepiped type). The test piece was immersed in water at 37 ° C. for 24 hours, and then a bending test was performed.
The bending test was performed using an Instron universal testing machine (manufactured by Instron) at a distance between fulcrums of 20 mm and a crosshead speed of 1 mm / min.

(2) Ambient light stability Adjust the height of the dental lamp (manufactured by Luna-Vue S Morita Manufacturing Co., Ltd.) so that the sample installation part is exposed to light with an illuminance of 8000 ± 1000 lp using an illuminance meter. A slide glass (26 × 16 mm, thickness 2 mm) was placed on a glass paste plate lined with matte black paper, and then a sample of about 30 mg was collected on the slide glass (26 × 16 mm, thickness 2 mm). After exposing the sample to the sample setting section for 60 ± 5 seconds, the sample was taken out from the sample setting section and immediately pressed against another slide glass to form a thin layer. If the state of the sample at this time was not physically uniform, it was determined that curing had started, and the time until curing was evaluated in 5-second increments. The longer this time, the better the ambient light stability.

(3) Discoloration of cured product a) Dental photocurable composition (excluding dental adhesive)
After filling each of the prepared dental photocurable compositions into a stainless steel mold (15φ × 1 mm: disk shape), a cover glass was placed from above and pressure-welded using a glass plate. A photopolymerization irradiator (Grip Light II: manufactured by Matsukaze) is used to irradiate the cover glass with light for 1 minute to cure it. After removing the cured product from the mold, the cover glass is removed and the color tone of this test piece is adjusted. I measured the color.
Color measurement is performed by placing the test piece on the background of a standard white plate (D65 / 10 ° X = 81.07, Y = 86.15, Z = 93.38) and using a spectrocolorimeter (manufactured by BIC Chemie). Under certain conditions (light source: C, viewing angle: 2 °, measurement area: 11 mm). Then, after exposing the test piece to light for 24 hours with a xenon lamp light exposure tester (Suntest CPS +), the color tone of the test piece was measured again, and the difference in discoloration was represented by ΔE calculated from the following formula. ..
ΔE = {(ΔL *) ² + (Δa *) ² + (Δb *) ² } ^1/2
ΔL * = L1 * -L2 *
Δa * = a1 * -a2 *
Δb * = b1 * -b2 *
Here, L1 * is the brightness index before light exposure, L2 * is the brightness index after light exposure, a1 * and b1 * are the color quality indexes before light exposure, and a2 * and b2 * are the color quality indexes after light exposure. Is.
b) Dental photocurable composition (dental adhesive)
A polyethylene frame with a thickness of 50 μm was fixed on a glass plate, the prepared dental photocurable composition was applied into the frame, and air drying was repeated until the liquid level did not move, resulting in a thickness of 50 μm or more. By the way, the glass plate is pressure-welded and irradiated with light for 1 minute using a photopolymerization irradiator (Grip Light II: manufactured by Matsukaze) to cure it. The color tone was measured. Color measurement is performed by placing the test piece on the background of a standard white plate (D65 / 10 ° X = 81.07, Y = 86.15, Z = 93.38) and using a spectrocolorimeter (manufactured by BIC Chemie). Under certain conditions (light source: C, viewing angle: 2 °, measurement area: 11 mm). Then, the test piece was immersed in water at 37 ° C. for 2 months, the color tone of the test piece was measured again, and the difference in discoloration was represented by ΔE calculated from the following formula.
ΔE = {(ΔL *) ² + (Δa *) ² + (Δb *) ² } ^1/2
ΔL * = L1 * -L2 *
Δa * = a1 * -a2 *
Δb * = b1 * -b2 *
Here, L1 * is a brightness index before immersion, L2 * is a brightness index after immersion, a1 * and b1 * are color quality indexes before immersion, and a2 * and b2 * are color quality indexes after immersion.

(4) Evaluation of storage stability The prepared dental photocurable composition is stored under a shield in an incubator set at 50 ° C., and after 90 days, (3) a test equivalent to discoloration of the cured product, aryl iodonium The precipitation of salt was confirmed. Storage stability was evaluated from the changes over time between the initial value and the value after 90 days at 50 ° C. For precipitation, the paste was discharged from the syringe and the presence or absence of precipitation was confirmed. The one with no precipitation was designated as A, the one with slight precipitation was designated as B, and the one with obvious precipitation was designated as C. For each composition, a dental photocurable composition from which the aryliodonium salt was removed was prepared as a reference sample, and it was confirmed that all of them had no precipitate.

(5) Evaluation of Durable Adhesive Strength The crown of the extracted mandibular central incisor is cut, and the cow tooth fragments are embedded with epoxy resin. The embedded cow tooth is poured with water, and the dentin is exposed with # 600 water-resistant abrasive paper, washed with water, and dried.
A double-sided tape with a hole with a diameter of 4 mm is attached to the exposed dentin to define the adhesive surface. A plastic mold (inner diameter 4 mm, height 2 mm or 4 mm) is fixed to the specified surface, a dental curable composition is applied to the adhesive surface, and a photopolymerization irradiator (Grip Light II: manufactured by Matsukaze) is used for 20 seconds. Irradiate with light to cure. After that, the dental composite resin "Beauty Fill Flow Plus" (Shofu Inc.) is filled in the mold, and light irradiation is performed again for 20 seconds to cure. The plastic mold was removed to prepare an adhesion test piece. After immersing this adhesive test piece in distilled water at 37 ° C for 24 hours, using an Instron universal testing machine (Instron 5567, manufactured by Instron), the dentin adhesiveness due to the shear adhesion strength at a crosshead speed of 1 mm / min. A test was conducted and the initial adhesive strength was measured.
Further, an adhesion test piece was prepared and immersed in distilled water at 37 ° C. for 24 hours, and then subjected to a thermal cycle of 10,000 times (immersed alternately at 55 ° C./30 seconds and 5 ° C./30 seconds) to test the dentin adhesion. The result of this was taken as the durable adhesive strength.

[Examples 1 to 12]
The dental photocurable compositions of Examples 1 to 12 exhibited high bending strength, excellent ambient light stability, and high discoloration resistance, and even after 90 days at 50 ° C., deterioration and precipitation of discoloration resistance were almost observed. Excellent storage stability.

[Comparative Examples 1 and 2]
The dental photocurable composition of Comparative Example 1 had low ambient light stability, remarkable discoloration, and precipitation of an aryliodonium salt was observed. It was confirmed that the dental photocurable composition of Comparative Example 2 had low bending strength and large discoloration.

Table 5 shows the evaluation results of the dental photocurable compositions (dental resin cement) of Examples and Comparative Examples.

〔実施例１３〜２２〕
実施例１３〜２２の歯科用光硬化性組成物は高い曲げ強度及び優れた環境光安定性、高い耐変色性を示し、また５０℃９０日後においても耐変色性の低下及び析出はほぼ認められず、保存安定性に優れる。

[Examples 13 to 22]
The dental photocurable compositions of Examples 13 to 22 showed high bending strength, excellent ambient light stability, and high discoloration resistance, and even after 90 days at 50 ° C., deterioration and precipitation of discoloration resistance were almost observed. Excellent storage stability.

[Comparative Examples 3 to 4]
The dental photocurable composition of Comparative Example 3 was markedly discolored, and precipitation of an aryliodonium salt was observed. It was confirmed that the dental photocurable composition of Comparative Example 4 had low bending strength and large discoloration.

Table 6 shows the evaluation results of the dental photocurable compositions of Examples and Comparative Examples.

〔実施例２３〜２８〕
実施例２３〜２８の歯科用光硬化性組成物は高い曲げ強度及び優れた環境光安定性を示し、また５０℃９０日後においてもアリールヨードニウム塩の析出は認められず、保存安定性に優れる。

[Examples 23 to 28]
The dental photocurable compositions of Examples 23 to 28 show high bending strength and excellent ambient light stability, and no precipitation of aryliodonium salt is observed even after 90 days at 50 ° C., and the storage stability is excellent.

[Comparative Examples 5 to 8]
The dental photocurable compositions of Comparative Examples 5 and 6 had low bending strength and ambient light stability, and precipitation of an aryliodonium salt was observed after 90 days at 50 ° C. It was confirmed that the dental photocurable compositions of Comparative Examples 7 and 8 had low bending strength, and that Comparative Example 8 had low ambient light stability.

なお、表７における−は、アリールヨードニウム塩を含まないことを表す。

In Table 7, − indicates that the aryl iodonium salt is not contained.

[Examples 29 to 36]
The dental photocurable compositions of Examples 29 to 36 have high adhesive strength, particularly high durable adhesiveness, no precipitation of aryliodonium salt is observed even after 90 days at 50 ° C., and discoloration after immersion in water is extremely low. Excellent storage stability.

[Comparative Examples 9 and 10]
The dental photocurable compositions of Comparative Examples 9 and 10 had low adhesive strength and color stability, and precipitation of an aryliodonium salt was observed after 90 days at 50 ° C. From these results, the effectiveness of the aryliodonium salt having a specific structure was shown.

In the above examples, the composite resin for dental filling, the dental resin cement and the dental adhesive have been described, but the present invention can be used for other dental photocurable compositions without any limitation.

Claims (7)

In (c) a photopolymerization initiator used in a dental photocurable composition,
(C-1) Photosensitizer, (c-2) Polymerization accelerator, and (c-3) formula (1):

(In the formula, R1 represents an organic group bonded to I, R2 represents an alkyl group in which a part of a hydrogen atom is substituted with a fluorine atom, and b represents the number thereof, which is an integer of 1 to 5. ), A photopolymerization initiator containing an aryliodonium salt. The photopolymerization initiator according to claim 1, wherein R2 is an aryliodonium salt which is an alkyl group in which 80% or more of hydrogen atoms are substituted with fluorine atoms according to the formula (1) of (c-3). A dental photocurable composition comprising (c) a photopolymerization initiator according to claim 1 and (a) a polymerizable monomer. The (c) photopolymerization initiator according to claim 1.
A dental photocurable composition comprising (a) a polymerizable monomer and (b) a filler. (A) With respect to 100 parts by mass of the polymerizable monomer
(C-1) Photosensitizer: 0.1 to 5 parts by mass,
(C-2) Polymerization accelerator: 0.01 to 10 parts by mass, and aryl iodonium salt represented by the formula (1) in (c-3): 0.01 to 10 parts by mass,
(C) The dental photocurable composition according to any one of claims 1 to 4, which contains a photopolymerization initiator. (A) With respect to 100 parts by mass of the polymerizable monomer
(B) The dental photocurable composition according to claim 5, wherein the filler contains 10 to 1900 parts by weight. Any of claims 3 to 6, which are dental adhesives, dental composite resins, dental abutment construction materials, dental resin cements, dental surface covering materials, dental pit fissure sealing materials, and dental nail polish materials. The dental photocurable composition according to.