JP5574945B2 - Photocurable composition - Google Patents

Description

  The present invention relates to a photocurable composition and an acetal derivative of a novel compound camphorquinone which is a component of a photopolymerization initiator suitable for blending with the photocurable composition. The photocurable composition is suitable for a dental composition such as a dental adhesive.

  A photocurable composition that cures when irradiated with light is used in various applications. In the field of dentistry, for example, a dental adhesive, a dental restoration material, and the like are exemplified.

  In the case of a tooth cavity damaged by caries or the like having a relatively small cavity in the first mid-stage, direct restoration by composite resin is often performed from the viewpoint of aesthetics, simplicity of operation, and rapidity. On the other hand, a prosthesis made of metal, ceramics, or dental resin is often used for repairing a relatively large cavity.

Restorative materials such as composite resins and prostheses do not have adhesiveness to the tooth. Therefore, in order to adhere the restorative material to the tooth, a dental adhesive composed of a curable composition containing a polymerizable monomer component and a polymerization initiator component is used in combination. The polymerizable monomer used in such adhesives is usually a (meth) acrylate polymerizable monomer from the viewpoint of availability and safety, but it adheres to the tooth. The power is not enough. For example, in the case of the adhesion of the composite resin to the tooth, the adhesive strength of the adhesive can only overcome the internal stress generated when the composite resin is cured, that is, the tensile stress generated at the interface between the tooth and the composite resin. Often the adhesive strength is not reached.
Furthermore, the adhesive strength is often not sufficient to withstand the force applied by occlusion.

  Therefore, in order to improve the adhesive strength of these dental adhesives, the following pretreatment is applied to the tooth structure during use. That is, 1) Apply a pretreatment material for etching treatment to hard tooth (mainly enamel mainly composed of hydroxyapatite), and 2) As a penetration enhancer called a primer The pretreatment material is applied.

  Here, as the pretreatment material for the former etching treatment, an acid aqueous solution for decalcifying the tooth surface is generally used, and an aqueous solution of phosphoric acid, citric acid, maleic acid or the like is used.

  On the other hand, the latter primer is a sponge exposed on the dentin surface after the demineralization and the demineralized enamel surface with the pretreatment material (acid aqueous solution) for the etching treatment. It must be capable of highly promoting penetration into fine gaps in the shape of collagen fibers. From this requirement, a hydrophilic polymerizable monomer having good affinity with the above-mentioned tooth substance such as hydroxyethyl methacrylate, or a polymerizable monomer composition containing an organic solvent for further increasing permeability is used. .

  The primer itself usually does not contain a polymerization initiator, but the polymerization that is caused by the action of radicals generated in the adhesive during the curing reaction of the adhesive for composite resin applied thereon. The polymerizable monomer is polymerized and cured.

  Furthermore, recently, a polymer containing a polymerizable monomer having an acidic group such as a phosphate ester group or a carboxyl group and having a deashing ability in the primer or the adhesive itself has been widely used.

  As the polymerization initiator blended in the dental adhesive used in this way, a photopolymerization initiator is frequently used (for example, Patent Documents 1 and 2). The photopolymerization initiator hardens the dental adhesive easily in a short time by irradiating the dental adhesive with light having a wavelength in the visible light region when it is desired to initiate polymerization.

  A dental adhesive that can be easily and quickly bonded at an arbitrary timing can greatly reduce patient pain and practitioner fatigue during dental treatment. Therefore, blending a photopolymerization initiator with a dental adhesive can greatly improve the utility value of the dental adhesive.

  Conventionally, a dental adhesive containing a photopolymerization initiator is housed in a light shielding container that shields light. The reason is that the dental adhesive housed in the container is exposed to visible light radiated from the indoor light source or visible light contained in natural light, thereby preventing the adhesive from hardening. Since the dental adhesive in which the conventional photopolymerization initiator is blended is stored in the light shielding container, it is avoided that the dental adhesive is cured before use.

  However, when the light shielding container is used, the remaining amount of the dental adhesive housed in the container cannot be directly visually confirmed. Therefore, every time it is necessary to check the remaining amount, the lid of the light shielding container is removed and the remaining amount is visually confirmed. Or the mass of the light shielding container containing the adhesive is measured, and the remaining amount of the adhesive is estimated.

  However, the presence of visible light is indispensable for visual recognition. Even if the presence of this visible light is weak, if it is exposed to visible light for a long period of time, such as a storage period before use, it will lead to the hardening of the dental adhesive.

  As described above, conventionally, there is no photocurable composition that can be stored in a transparent container.

JP-A-2004-196949 (Claims, Claims 1 and 5) JP 2005-89729 (Claims, Claims 1 and 7)

  In order to solve the above problems, the present inventor has made various studies on photopolymerization initiators. In the course of these studies, it was conceived to use acetal derivatives derived from these carbonyl compounds in place of the carbonyl compounds used as ordinary visible light polymerization initiators. According to the study by the present inventor, these acetal derivatives hardly absorb light in the visible wavelength region. Furthermore, the acetal derivative is rapidly hydrolyzed when an acid coexists, and is derived into a carbonyl compound having the original photopolymerization initiation function.

  Therefore, even if the mixture of an acetal derivative and a polymerizable monomer is stored in a transparent container, polymerization does not occur. In use, by adding an acid component to this mixture, the acetal derivative is hydrolyzed in a short time to be derived into a carbonyl compound having a photopolymerization initiating function. In this state, the polymerizable monomer is polymerized by irradiating the mixture with visible light.

  The present inventor has conceived that the above problems can be solved by utilizing the chemical and physical characteristics unique to these acetal derivatives, and the present invention has been completed.

  Therefore, the present invention can be operated and stored under visible light, for example, a photocurable composition that can be stored and stored in a transparent container, and an acetal derivative of camphorquinone useful as a photopolymerization initiator. The purpose is to provide.

  The present invention for achieving the above object is as follows.

  [1] a) a polymerizable monomer; b) an acidic component; c) a photopolymerization initiator precursor comprising an acetal derivative of a compound having one or more carbonyl groups and having absorption in the visible light region; A photocurable composition comprising an acidic component of b) and a photopolymerization initiator precursor of c).

  [2] The photocurable composition according to claim 1, wherein b) the acidic component contains an acidic group-containing polymerizable monomer.

  [3] c) The photopolymerization initiator precursor comprising an acetal derivative of a compound having one or more carbonyl groups and having absorption in the visible light region is an acetal derivative of an α-diketone compound, [1] or [ 2].

  [4] The photocurable composition according to any one of [1] to [3], further comprising d) water.

  [5] The photocurable composition according to any one of [1] to [4], further comprising a chemical polymerization initiator.

  [6] A dental curable composition comprising the photocurable composition according to any one of [1] to [5].

  [7] The following formula (1) or (2)

(R ^{1 to} R ⁴ are alkyl groups having 1 to 20 carbon atoms which may be the same or different, and the ends of any two alkyl groups of R ^{1 to} R ⁴ are bonded to each other to form a ring. A structure may be formed.)
An acetal derivative of camphorquinone represented by

  The photocurable composition of the present invention contains an acetal derivative. The acetal derivative does not substantially have a light absorption wavelength region in the visible light region and does not function as a visible light polymerization initiator. Therefore, the present photocurable composition containing an acetal derivative is not cured under visible light. On the other hand, an acetal derivative is immediately induced by a carbonyl compound when an acid coexists, and exhibits a visible light polymerization function. The visible light polymerization function in this case refers to the ability to absorb light having a wavelength of 380 nm to 750 nm and function effectively as a polymerization initiator.

  The present photocurable composition can be stored and handled under visible light before use. In use, an acetal derivative and an acidic component are reacted in advance to derive the acetal derivative into a carbonyl compound. Thereby, this photocurable composition exhibits original photopolymerizability, and it hardens | cures by irradiation of visible light.

  Therefore, the present photocurable composition is extremely easy to handle. In particular, it is useful when an acidic compound is contained as in a dental curable composition such as a dental adhesive.

The photocurable composition of the present invention is
a) a photopolymerization initiator (hereinafter simply referred to as “c”) comprising an acetal derivative of a compound having a polymerizable monomer, b) an acidic component, and c) one or more carbonyl groups and having absorption in the visible light region. Sometimes abbreviated as photopolymerization initiator. ), And
The acidic component of b) and the photopolymerization initiator of c) are packaged.
It is a photocurable composition.

[a) Polymerizable monomer
The a) polymerizable monomer used in the present invention is one or more, preferably one unsaturated group such as a styrene monomer or an acrylic monomer, as long as it is a radical polymerizable monomer. Can be arbitrarily used. These monomers can also be mixed and used at an arbitrary ratio.

  The photocurable composition of the present invention is particularly suitable for a dental curable composition. Therefore, a polymerizable monomer suitable for blending in a dental photocurable composition will be described below.

  As a polymerizable monomer suitable for a dental curable composition, particularly a dental adhesive, there is a (meth) acrylic monomer (indicating acrylic and methacrylic). These (meth) acrylic monomers may be used alone or in admixture of two or more.

  A non-acidic (meth) acrylic polymerizable monomer (that is, a (meth) acrylic polymerizable monomer having no acidic group in the molecule) may be a compound having at least a (meth) acrylic group in the molecule. For example, known compounds can be used without any limitation. Specific examples include methyl (meth) acrylate, ethyl (meth) acrylate, glycidyl (meth) acrylate, 2-cyanomethyl (meth) acrylate, benzyl (meth) acrylate, polyethylene glycol mono (meth) acrylate, allyl (meth). Examples include monomethacrylate monomers such as acrylate, 2-hydroxyethyl (meth) acrylate, 3-hydroxypropyl (meth) acrylate, glyceryl mono (meth) acrylate, and 2- (meth) acryloxyethyl acetyl acetate.

  Furthermore, ethylene glycol di (meth) acrylate, diethylene glycol di (meth) acrylate, triethylene glycol di (meth) acrylate, nonaethylene glycol di (meth) acrylate, propylene glycol (meth) acrylate, dipropylene glycol di (meth) acrylate 2,2′-bis [4- (meth) acryloxyethoxyethoxy] propane, 2,2′-bis [4- (meth) acryloxyethoxyethoxyphenyl] propane, 2,2′-bis {4- [ 3- (meth) acryloxy-2-hydroxypropoxy] phenyl} propane, 1,4-butanediol di (meth) acrylate, 1,6-hexanediol di (meth) acrylate, trimethylolpropane tri (meth) acrylate, Urethane (medium ) Acrylates, polyfunctional (meth) acrylate monomers such as epoxy (meth) acrylate.

  The (meth) acrylic monomer may include an acidic group-containing (meth) acrylic monomer having an acidic group. In particular, it is suitable for use in a dental curable composition such as a dental adhesive. As will be described later, in the photocurable composition of the present invention, in addition to a) the polymerizable monomer, b) an acidic component is contained. Thus, when a) an acidic group-containing (meth) acrylic monomer is used as the polymerizable monomer, the acidic group-containing (meth) acrylic monomer also corresponds to b) an acidic component.

  The compounding amount of these acidic group-containing (meth) acrylic monomers is a photopolymerization initiator precursor 1 that is not less than the lower limit amount (the acidic component is c) that sufficiently exhibits the action as b) acidic component described later. The amount is preferably 0.01 mol or more, more preferably 0.1 mol or more). Moreover, you may mix | blend an acidic group containing (meth) acrylic-type monomer as all of a) a polymerizable monomer. If the photocurable composition is used as a dental curable composition such as a dental adhesive, from the viewpoint of adjusting the permeability of the adhesive to the tooth or improving the strength of the cured product. It is preferable to use in combination with a non-acidic (meth) acrylic monomer having no acidic group.

  If a non-acidic (meth) acrylic monomer is used in combination, the blending amount of the acidic group-containing (meth) acrylic monomer is from the viewpoint of improving the adhesive strength to both enamel and dentin. The total polymerizable monomer is more preferably used in an amount of 5% by mass or more, and particularly preferably in the range of 10-80% by mass.

  If the blending amount of the acidic group-containing (meth) acrylic monomer is small, the adhesive strength to enamel tends to decrease, and conversely if it is large, the adhesive strength to dentin tends to decrease.

As an acidic group of an acidic group-containing (meth) acrylic monomer, a phosphinico group {= P (═O) OH}, a phosphono group {—P (═O) (OH) ₂ }, a carboxyl group {—C ( = O) OH}, dihydrogen phosphate monoester group {—O—P (═O) (OH) ₂ }, hydrogen phosphate diester group {(—O—) ₂ P (═O) OH}, sulfo group Examples thereof include a functional group that exhibits acidity in an aqueous solution such as an organic group having (—SO ₃ H) and an acid anhydride skeleton {—C (═O) —O—C (═O) —}.

Among these functional groups, the stability to water is high, and dissolution of the smear layer on the tooth surface and tooth decalcification can be performed mildly, so the carboxyl group, dihydrogen phosphate monoester group, hydrogen phosphate diester group The dihydrogen phosphate monoester group and the hydrogen phosphate diester group are most preferable in that higher adhesive strength can be obtained with respect to the tooth enamel.

Examples of the (meth) acrylic monomer having a dihydrogen phosphate monoester group or a hydrogen phosphate diester group include 2- (meth) acryloyloxyethyl dihydrogen phosphate and bis [2- (meth) acryloyloxyethyl]. Hydrogen phosphate, 2- (meth) acryloyloxyethylphenyl hydrogen phosphate, 6- (meth) acryloyloxyhexyl dihydrogen phosphate, 6- (meth) acryloyloxyhexylphenyl hydrogen phosphate, 10- (meth) acryloyloxy Decyl dihydrogen phosphate, 1,3-di (meth) acryloylpropane-2-dihydrogen phosphate, 1,3-di (meth) acryloylpropane-2-phenyl hydrogen phosphate , Bis [5- {2- (meth) acryloyloxy} heptyl] hydrogen phosphate, and the like.
Examples of the (meth) acrylic monomer having a carboxyl group include 4- (meth) acryloxyethyl trimellitic acid, 11- (meth) acryloyloxy-1,1-undecanedicarboxylic acid, 1,4-di (meth) ) Acryloyloxypyromellitic acid, 2- (meth) acryloyloxyethylmaleic acid, 2- (meth) acryloyloxyethylphthalic acid, 2- (meth) acryloyloxyethylhexahydrophthalic acid and the like.

[b) Acidic component
When the photocurable composition is photocured with visible light, the b) acidic component that is a constituent component of the photocurable composition is converted from a photopolymerization initiator precursor comprising the acetal derivative of c) from a carbonyl compound. It plays a role in inducing to a photopolymerization initiator.

  As long as the acidic component is a compound having a pH of 3 or less when dissolved in 10% by mass in a 50% aqueous ethanol solution, any compound can be used as long as it is not contrary to the object of the present invention.

  As the acidic component, inorganic acids and organic acids can be used.

  Examples of the inorganic acid include phosphoric acid, sulfuric acid, hydrochloric acid, nitric acid and the like. In view of safety to the human body, phosphoric acid is preferable.

  Examples of organic acids include carboxylic acids such as formic acid, acetic acid, citric acid, and maleic acid, sulfonic acids such as methanesulfonic acid and p-toluenesulfonic acid, phosphoric acid monoesters such as phosphoric acid monoethyl ester and phosphoric acid diethyl ester, Illustrative are phosphonic acids such as phosphoric acid diester, methylphosphonic acid, and ethylphosphonic acid. In consideration of safety to the human body, carboxylic acid, phosphoric acid monoester, and phosphoric acid diester are preferable.

  Although the compounding quantity of these acidic components changes with acidic components, generally 0.01-100 mol is preferable with respect to 1 mol of photoinitiator precursors, and 0.1-10 mol is more preferable.

  Further, as the acidic component, the acidic group-containing (meth) acrylic monomer described in the above-mentioned a) polymerizable monomer can also be used. In this case, the compounding amount of the acidic component is preferably 0.01 mol or more, more preferably 0.1 mol or more, more preferably 0.1 mol or more with respect to 1 mol of the photopolymerization initiator precursor. a) Any blending amount up to the total amount of the polymerizable monomer can be employed.

[c) Photopolymerization initiator precursor comprising an acetal derivative of a compound having one or more carbonyl groups and having absorption in the visible light region]
The photopolymerization initiator precursor of c) consists of an acetal derivative. This acetal derivative can be produced using a carbonyl compound (ketone) having one or more, preferably two carbonyl groups in the molecule as a raw material.

  As the carbonyl compound, known photopolymerization initiators that generate radicals upon irradiation with visible light can be used without limitation.

  Examples of such a carbonyl compound include a hydrogen abstraction type photo radical generator. More specifically, the hydrogen abstraction type photoradical generator is not particularly limited as long as it is a compound that is excited by light irradiation to extract a hydrogen atom from a hydrogen donor and generate a radical. Can be used.

  Examples of the hydrogen abstraction type radical generator include diaryl ketone compounds, α-diketone compounds, ketocoumarin compounds, and the like.

  Specific examples of the diaryl ketone compound include 4,4-bis (dimethylamino) benzophenone, 4,4-bis (diethylamino) benzophenone, 9-fluorenone, 3,4-benzo-9-fluorenone, 2-dimethylamino- 9-fluorenone, 2-methoxy-9-fluorenone, 2-chloro-9-fluorenone, 2,7-dichloro-9-fluorenone, 2-bromo-9-fluorenone, 2,7-dibromo-9-fluorenone, 2- Nitro-9-fluorenone, 2-acetoxy-9-fluorenone, benzanthrone, anthraquinone, 1,2-benzanthraquinone, 2-methylanthraquinone, 2-ethylanthraquinone, 1-dimethylaminoanthraquinone, 2,3-di Tyranthraquinone, 2-tert-butylanthraquinone, 1-chloroanthraquinone, 2-chloroanthraquinone, 1,5-dichloroanthraquinone, 1,2-dimethoxyanthraquinone, 1,2-diacetoxy-anthraquinone, 5,12-naphthacenequinone, 6 1,3-pentacenequinone, xanthone, thioxanthone, 2,4-dimethylthioxanthone, 2,4-diethylthioxanthone, 2-chlorothioxanthone, 9 (10H) -acridone, 9-methyl-9 (10H) -acridone And dibenzosuberenone.

  Specific examples of α-diketone compounds include camphorquinone, benzyl, diacetyl, acetylbenzoyl, 2,3-pentadione, 2,3-octadione, 4,4′-dimethoxybenzyl, 4,4′-oxybenzyl, 9,10-phenanthrenequinone, acenaphthenequinone and the like.

  The ketocoumarin compounds include 3-benzoylcoumarin, 3- (4-methoxybenzoyl) coumarin, 3-benzoyl-7-methoxycoumarin, 3- (4-methoxybenzoyl) 7-methoxy-3-coumarin, 3-acetyl-7. -Dimethylaminocoumarin, 3-benzoyl-7-dimethylaminocoumarin, 3,3'-coumarinoketone, 3,3'-bis (7-diethylaminocoumarino) ketone, etc. can be mentioned.

  Moreover, what generate | occur | produces a radical by self-cleavage by light irradiation can also be utilized. Examples of such carbonyl compounds include acylphosphine oxides and trichloroacetophenone.

  Furthermore, a hydrogen abstraction-type photoradical generator is preferable in that the polymerization activity upon irradiation with light is higher than that of other compounds, and among them, a diaryl ketone compound or an α-diketone compound is particularly preferable. Of these, α-diketone compounds are most preferred.

  In addition, as for the hydrogen donor, a polymerizable monomer usually has its function, but amines can be used as a suitable hydrogen donor. Of these, tertiary amines are more preferred. In particular, N, N-dimethylaniline, N, N-dimethyl-p-toluidine, N, N-dimethyl-m-toluidine, p-bromo-N, N-dimethylaniline, m-chloro-N, N-dimethylaniline, Aromatic tertiary amines such as p-dimethylaminobenzaldehyde, p-dimethylaminoacetophenone, p-dimethylaminobenzoic acid, p-dimethylaminobenzoic acid ethyl ester, p-dimethylaminobenzoic acid amyl ester are more preferred. Most preferred are p-dimethylaminobenzoic acid esters such as p-dimethylaminobenzoic acid ethyl ester and p-dimethylaminobenzoic acid amyl ester.

  For the acetalization reaction of the carbonyl group of the ketone compound, any known reaction can be used without any limitation.

  For example, there is a method in which a carbonyl compound and an alcohol compound are reacted under dehydration conditions in the presence of an acid catalyst. In this method, a carbonyl compound and an alcohol compound are reacted in an organic solvent such as methylene chloride, acetonitrile, toluene, dimethylformamide, dimethyl sulfoxide, diethyl ether, tetrahydrofuran in the presence of a dehydrating agent such as molecular sieve. To obtain an acetal compound.

  When the boiling point of the carbonyl compound and the alcohol compound is higher than that of benzene, an acetal compound can also be obtained by attaching a water separator such as Dean Stark and heating and refluxing the carbonyl compound and the alcohol compound in the presence of an acid catalyst. Examples of the acid catalyst include organic acids and inorganic acids. As the organic acid, benzenesulfonic acid, p-toluenesulfonic acid and the like are preferable. Inorganic acids include sulfuric acid, phosphoric acid, nitric acid, solid acids include montmorillonite K10, and Lewis acids include trimethylmethylsilyl triflate, tin (II) triflate, lanthanum (III) triflate, scandium (III ) Triflate and the like are preferable.

  As a method for acetalizing a carbonyl compound, an alkoxytri-lower alkylsilane (tri-lower alkylsilyloxyalkane) such as an alkoxytriethylsilane (triethylsilyloxyalkane) or an alkoxytriethylsilane (triethylsilyloxyalkane) in the presence of an acid catalyst. ) Can also be used. In this case, the reaction proceeds quickly, and the by-product is hexamethyldisiloxane, which is preferable because the reverse reaction does not proceed. In this reaction, dimethylacetal is obtained by reacting a carbonyl compound with methyloxytrimethylsilane. Further, when 1,2-bis (trimethylsilyloxy) ethane is reacted, a cyclic ethylene acetal is obtained. As the acid catalyst that can be used in these reactions, the acid catalysts described above can be used.

  Also, an acetal compound can be obtained by reacting a carbonyl compound and an ortho ester compound in the presence of an acid catalyst. For example, when trimethyl orthoformate is reacted with a carbonyl compound, the carbonyl compound can be converted to dimethyl acetal.

  Among the methods for obtaining the acetal compound described above, a method in which a carbonyl compound and alkoxytrimethylsilane are reacted in the presence of an acid catalyst is more preferable. As the acid catalyst, a Lewis acid catalyst such as trimethylmethylsilyl triflate can be suitably used.

The acetalization of these carbonyl compounds can be confirmed by measuring a nuclear magnetic resonance spectrum ( ¹ H-NMR). That is, the molecular structure of the acetal compound described above can be determined from observation of chemical shift and spin-spin coupling by measurement of ¹ H-NMR spectrum. Specifically, it has a feature that a new peak derived from protons of an acetal structure is observed at 3.1 to 4.3 ppm that was not observed before acetalization.

  Preferred photopolymerization initiator precursors produced by the above production method and the like are represented by the following formulas (1) and (2).

Here, R ^{1 to} R ⁴ are preferably an alkyl group having 1 to 20 carbon atoms which may be the same or different, more preferably an alkyl group having 1 to 5 carbon atoms, and ^{1 to} R ¹ carbon atoms. Most preferred is an alkyl group of 3. The ends of any two alkyl groups of R ^{1 to} R ⁴ may be bonded to each other to form a ring structure. In this case, the alkylene group formed by bonding the ends of the two alkyl groups to each other preferably has 2 to 5 carbon atoms, and particularly preferably 2 to 3 carbon atoms.

  Hereinafter, specific examples of the photopolymerization initiator precursor will be described.

  The blending amount of the photopolymerization initiator precursor of c) is preferably 0.001 to 20 parts by mass, more preferably 0.01 to 10 parts by mass based on 100 parts by mass of the polymerizable monomer a).

  The present photocurable composition comprising the above components a), b), and c) is a state (packaging) in which b) the acidic component and c) the photopolymerization initiator precursor are separated before use. Save with.

  The a) polymerizable monomer may be added to any of b) packaging of acidic components or c) photopolymerization initiator precursor packaging. Or it is good also as a packaging different from these packaging. The packaging container is preferably a visible light transmissive container. By keeping the components a), b), and c) in the above-described packaged state, the components can be stably stored in visible light without curing the photocurable composition before use.

  When using the photocurable composition, each packaging component stored in a packaged state is mixed to prepare a photocurable composition, which is applied and molded according to a desired usage form, and light. By irradiating, the photocurable composition is cured. The mixing ratio of b) acidic component packaging and c) photopolymerization initiator precursor packaging is not particularly limited. For example, b) photopolymerization of c) with respect to 1 part by mass of the acidic component packaging. What is necessary is just to employ | adopt from the range of 0.01-100 mass parts of the packaging of an initiator precursor. Usually, it is desirable to mix in equal amounts. Each of b) acidic component packaging and c) photopolymerization initiator precursor packaging contains the components a), b) and c) described above after mixing them in such a ratio. Each component may be contained so that the amount is reached.

  After mixing each packaging component, the mixture waits for the acetal derivative which is a photopolymerization initiator precursor of c) to be induced by a carbonyl compound, and then used as a photocurable composition. Since the retention time varies somewhat depending on the types of c) photopolymerization initiator precursor, b) acidic component, and other components, it is preferable to determine the retention time by preliminary experiments. Usually, holding for about 5 seconds is sufficient.

  For light irradiation, a light source such as a carbon arc, a xenon lamp, a metal halide lamp, a tungsten lamp, a fluorescent lamp, sunlight, a helium cadmium laser, or an argon laser can be used without any limitation. Since the irradiation time varies depending on the wavelength and intensity of the light source and the shape and material of the cured body, it is preferable to determine in advance by preliminary experiments. In general, it is preferable to adjust the blending ratio of each component so that the irradiation time is in the range of about 5 to 60 seconds.

  The photocurable composition may further contain a chemical polymerization initiator. The chemical polymerization initiator is a compound in which two or more kinds of compounds come into contact with each other to generate radicals. For example, when using this photocurable composition as a dental adhesive, light may not fully reach the entire adhesive depending on the form of use. In this case, the portion becomes poorly cured. However, in the case where a chemical polymerization initiator is blended, the portion where the light has not sufficiently reached is cured by chemical polymerization, so that curing failure of this portion can be avoided.

  Typical chemical polymerization initiators include combinations of organic peroxides and amines, organic peroxides, combinations of amines and sulfinates, combinations of acidic compounds and aryl borates, barbituric acid, alkylboranes. And the like, and the like.

  Examples of compounds suitable for use in the chemical polymerization initiator are as follows. Examples of the organic peroxides include t-butyl hydroperoxide, cumene hydroperoxide, di-t-butyl peroxide, dicumyl peroxide, Examples include acetyl peroxide, lauroyl peroxide, benzoyl peroxide and the like. These can be used alone or in combination of two or more.

  As the amines, secondary or tertiary amines are preferable, and specific examples thereof include N-methylaniline, N-methyl-p-toluidine and the like as secondary amines. N, N-dimethylaniline, N, N-diethylaniline, N, N-di-n-butylaniline, N, N-dibenzylaniline, N, N-dimethyl-p-toluidine, N, N-diethyl -P-toluidine, N, N-dimethyl-m-toluidine, p-bromo-N, N-dimethylaniline, m-chloro-N, N-dimethylaniline, p-dimethylaminobenzaldehyde, p-dimethylaminoacetophenone, p -Dimethylaminobenzoic acid, p-dimethylaminobenzoic acid ethyl ester, p-dimethylaminobenzoic acid amyl ester, N, N-dimethylan Ranilic acid methyl ester, N, N-dihydroxyethylaniline, N, N-dihydroxyethyl-p-toluidine, p-dimethylaminophenethyl alcohol, p-dimethylaminostilbene, N, N-dimethyl-3,5-xylidine, 4-dimethylaminopyridine, N, N-dimethyl-α-naphthylamine, N, N-dimethyl-β-naphthylamine, tributylamine, tripropylamine, triethylamine, N-methyldiethanolamine, N-ethyldiethanolamine, N, N-dimethyl Hexylamine, N, N-dimethyldodecylamine, N, N-dimethylstearylamine, N, N-dimethylaminoethyl (meth) acrylate, N, N-diethylaminoethyl (meth) acrylate, 2,2 '-(n- Butylimino ) Diethanol and the like.

  Any aryl borate can be used as long as it has at least one boron-aryl bond in one molecule, but it has high storage stability, ease of handling, and availability. From the viewpoint of ease of use, aryl borates having four boron-aryl bonds in one molecule are most preferable. Specific examples of aryl borate (aryl borate ion) having four boron-aryl bonds in one molecule include tetraphenyl borate ion, tetrakis (p-chlorophenyl) borate ion, tetrakis (p-fluorophenyl) boric acid. Ion, tetrakis (3,5-bistrifluoromethyl) phenylborate ion, tetrakis [3,5-bis (1,1,1,3,3,3-hexafluoro-2-methoxy-2-propyl) phenyl] boron Acid ion, tetrakis (p-nitrophenyl) borate ion, tetrakis (m-nitrophenyl) borate ion, tetrakis (p-butylphenyl) borate ion, tetrakis (m-butylphenyl) borate ion, tetrakis (p -Butyloxyphenyl) borate ion, tetrakis (m-butyl) Kishifeniru) borate ions include salts of tetrakis (p- octyloxyphenyl) borate, tetrakis (m-octyloxyphenyl) boron compounds such as borate ions. As a cation forming a salt with a boron compound, a metal ion, a tertiary or quaternary ammonium ion, a quaternary pyridinium ion, a quaternary quinolinium ion, or a quaternary phosphonium ion may be used. it can.

  Among the above chemical polymerization initiators, a chemical polymerization initiator obtained by using a combination of an acidic compound and an aryl borate in combination with a + IV and / or + V vanadium compound is particularly suitable because of its high polymerization activity. Furthermore, the combined use of the above organic oxides is most preferable because the polymerization activity can be further enhanced.

  Specific examples of the vanadium compound include divanadium tetraoxide (IV), vanadyl oxalate (IV), vanadyl sulfate (IV), oxobis (1-phenyl-1,3-butanedionate) vanadium (IV), bis (Maltrate) oxo vanadium (IV), vanadium pentoxide (V), sodium metavanadate (V), ammonium metavanadate (V) and the like can be mentioned.

  The compounding amount of the chemical polymerization initiator is preferably 0.001 to 20% by mass, and 0.01 to 10% by mass based on the total mass of a) the polymerizable monomer and the acidic group-containing polymerizable monomer. % Is more preferable.

  The chemical polymerization initiator is usually from the viewpoint of storage stability. C) Packaging of the photopolymerization initiator precursor so that all of the two or more compounds that generate radicals by contact mixing do not coexist in the same package. The inside and b) acidic components are properly divided and mixed.

  The present photocurable composition may further contain water. For example, when the present photocurable composition is used as a dental adhesive, water can give the dental adhesive a decalcification function and a function of penetrating into the tooth, thereby improving the adhesive strength.

  The amount of water is usually preferably from 0.1 to 100 parts by weight, more preferably from 1 to 50 parts by weight, based on 100 parts by weight of the polymerizable monomer (a).

  When water is blended, it is preferable to blend water in the b) acidic component sachet.

  EXAMPLES Hereinafter, although an Example and a comparative example are given and this invention is demonstrated concretely, this invention is not restrict | limited at all by these. Abbreviations and abbreviations shown in the examples are as follows.

Abbreviations and abbreviations [polymerizable monomer having an acidic group derived from phosphoric acid]
PM1: 2-methacryloyloxyethyl dihydrogen phosphate PM2: bis (2-methacryloyloxyethyl) hydrogen phosphate PM: 1: 1 molar ratio mixture of PM1 and PM2

[Polymerizable monomer containing no acidic group]
BisGMA: 2,2′-bis (4- (2-hydroxy-3-methacryloxypropoxy) phenyl) propane 3G: triethylene glycol dimethacrylate HEMA: 2-hydroxyethyl methacrylate

[Volatile water-soluble organic solvent]
IPA: isopropyl alcohol

[Photoinitiator of the present invention]
It was synthesized by the method shown below. The obtained acetal derivative was measured for ¹ H NMR spectrum to confirm whether the carbonyl compound was acetalized. That is, the peak of 3.1 to 4.3 ppm is derived from the proton of the acetal structure, and was confirmed from the observation of this peak and the number of protons analyzed.
CQM: camphorquinone dimethyl acetal

Using acetonitrile as a solvent, camphorquinone and 2.2 equivalents of methoxytrimethylsilane were reacted at room temperature in the presence of trimethylsilyl trifluoromethanesulfonate. The product was isolated and purified by alumina gel column chromatography to obtain CQM (yield 42%).

¹ H NMR δ 1.11 (s, 6H), 1.16 (s, 3H), 1.43 (m, 2H), 1.75 (m, 2H), 2.03 (m, 1H), 3. 24 (s, 6H; derived from acetal structure)

CQDM: camphorquinone bis (dimethylacetal)

  In the same manner as CQM, camphorquinone and 4.4 equivalents of methoxytrimethylsilane were reacted in the presence of trimethylsilyl trifluoromethanesulfonate to obtain CQDM (yield 83%).

¹ H NMR δ 1.11 (s, 6H), 1.16 (s, 3H), 1.36 (m, 2H), 1.40 (m, 2H), 2.06 (m, 1H), 3. 24 (s, 12H; derived from acetal structure)

CQE: camphorquinone ethylene acetal

  In the same manner as CQM, CQE was obtained by reacting camphorquinone with 1.1 equivalents of 1,2-bis (trimethylsilyloxy) ethane in the presence of trimethylsilyl trifluoromethanesulfonate (yield 51%).

¹ H NMR δ 1.11 (s, 6H), 1.16 (s, 3H), 1.43 (m, 2H), 1.75 (m, 2H), 2.03 (m, 1H), 3. 90 (m, 4H; derived from acetal structure)

BNM: 4,4-Dimethoxybenzyldimethylacetal

  By operating in the same manner as CQM, BNM was obtained by reacting 4,4-dimethoxybenzyl with 2.2 equivalents of methoxytrimethylsilane in the presence of trimethylsilyl trifluoromethanesulfonate (yield 41%).

¹ H NMR δ 3.24 (s, 6H), 3.73 (s, 6H; derived from acetal structure), 6.70-7.75 (m, 8H)

AQE: Anthraquinone ethylene acetal

  In the same manner as in CQM, anthraquinone was reacted with 1.1 equivalents of 1,2-bis (trimethylsilyloxy) ethane in the presence of trimethylsilyl trifluoromethanesulfonate to obtain AQE (yield 33%).

¹ H NMR δ 4.02 (m, 4H; derived from acetal structure), 7.29-7.63 (m, 8H)

[Other photopolymerization initiators]
CQ: camphorquinone BN: benzyl AQ: anthraquinone [tertiary amine]
DMBE: ethyl p-N, N-dimethylaminobenzoate [polymerization inhibitor]
BHT: 2,6-di-t-butyl-p-cresol [organic peroxide]
TMBHO: 1,1,3,3-tetramethylbutyl hydroperoxide [vanadium compound]
BMOV: Bis (maltolate) oxovanadium (IV)
[Borate compounds]
PhBTEOA: Triethanolammonium tetraphenylborate

In the following examples and comparative examples, various measurements were performed by the following methods.

(1) Light resistance test The curable composition was put into a transparent screw tube bottle and irradiated with light under a fluorescent lamp of 10,000 lux for 24 hours. After irradiation, it was judged that the fluidity of the curable composition in the screw tube bottle was about the same as that before the light irradiation, and that the fluidity was lost.

(2) Photocuring test Liquid A and B of the curable composition used in the light resistance test are dropped into a mixing dish drop by drop and mixed, and a dental visible light irradiator (Tokuso Power Light, manufactured by Tokuyama Corporation). When irradiated with light for 30 seconds and changed to a solid state, it was evaluated as ◯, and when it was liquid or semi-liquid, it was evaluated as x.

(3) Adhesion test The front teeth of the cow were removed within 24 hours after slaughtering, and the enamel and dentin planes were cut out with a # 600 emery paper so as to be parallel to the labial surface under the water. Next, these surfaces were dried by blowing compressed air for about 10 seconds. After that, a double-sided tape with a hole having a diameter of 3 mm was attached to any surface of enamel and dentin.

  Next, paraffin wax having a hole with a thickness of 0.5 mm and a diameter of 8 mm was fixed on the circular hole so as to have the same center, thereby forming a simulated cavity. Liquid A and liquid B were mixed drop by drop in this simulated cavity and applied after 5 seconds. After leaving for 20 seconds, compressed air was blown for about 10 seconds to dry, and a dental visible light irradiator (Toxo Powerlite, For 30 seconds.

  Furthermore, a dental composite resin (Estellite Σ, manufactured by Tokuyama Dental Co., Ltd.) is filled on it, and irradiated with a visible light irradiator for 30 seconds to prepare an adhesive test piece, which is immersed in water at 37 ° C. overnight. Stored.

  After that, using a tensile tester (Autograph, manufactured by Shimadzu Corporation), it was pulled at a crosshead speed of 2 mm / min, and the tensile bond strength between the enamel or dentin and the composite resin was measured. For each test, four tensile bond strengths were measured by the above method, and the average value was taken as the bond strength after the durability test. The adhesive strength was evaluated using this value.

Example 1
Liquid A was prepared by mixing 1.2 g of BisGMA as a polymerizable monomer, 0.8 g of 3G and 3.0 g of HEMA, and 0.5 g of phosphoric acid as an acidic substance. Further, 5.0 g of HEMA as a polymerizable monomer, 0.2 g of CQM as a photopolymerization initiator, and 0.15 g of DMBE as other components were mixed to prepare a liquid B. About this composition, the light resistance test and the photocuring test were done. The composition of the adhesive and the evaluation results are shown in Table 1.

Examples 2-11
According to the method of Example 1, a composition having the composition shown in Table 1 was prepared using a phosphoric acid monomer as the acidic compound. In Example 11, as a chemical polymerization initiator, BMOV, which is a vanadium compound, was blended into the liquid A, and TMBHO, which is a peroxide, and PhBTEOA, which is a borate compound, were blended into the liquid B. A light resistance test and a photocuring test were performed on the obtained combinations of liquid A and liquid B. The composition of the adhesive and the evaluation results are shown in Table 1.

  In Examples 3, 4, 5 and 11, an adhesion test was performed. Moreover, in Example 3, the compounding quantity of PM which is an acidic component was 0.12 mol with respect to 1 mol of CQM which is a photoinitiator (photoinitiator precursor).

Reference example 1
In Example 5, A liquid and B liquid were prepared in the same manner as in Example 5, except that ordinary CQ was used instead of CQDM. A contact test was performed using each of the obtained liquid A and liquid B. The evaluation results are shown in Table 2. The adhesive strength was the same as in Example 5.

Comparative Examples 1-7
According to the method of Example, the composition of the composition shown in Table 3 was prepared using a phosphoric acid monomer as an acidic compound. A light resistance test and a photocuring test were performed for each combination of the obtained liquid A and liquid B. The composition of the adhesive and the evaluation results are shown in Table 3.

  In Examples 1 to 11, the photopolymerization initiator that is an essential component of the present invention was used. In any case, excellent light resistance and photocurability were exhibited.

  On the other hand, Comparative Examples 1 to 7 are those using a normal photopolymerization initiator that is not an essential component of the present invention. The test was not reached.

Claims (6)

a) a polymerizable monomer, b) an acidic component, and c) a photopolymerization initiator precursor composed of an acetal derivative of a compound having one or more carbonyl groups and absorbing in the visible light region. A dental photocurable composition comprising a photocurable composition comprising b) an acidic component and c) a photopolymerization initiator precursor. The dental photocurable composition according to claim 1, wherein the b) acidic component contains an acidic group-containing polymerizable monomer. c) The photopolymerization initiator precursor comprising an acetal derivative of a compound having one or more carbonyl groups and having absorption in the visible light region is an acetal derivative of an α-diketone compound. Dental photocurable composition. The dental photocurable composition according to any one of claims 1 to 3, further comprising d) water. The dental photocurable composition according to any one of claims 1 to 4, further comprising a chemical polymerization initiator. Following formula (1) or (2)

(R ^{1 to} R ⁴ are the same or different alkyl groups having 1 to 20 carbon atoms . )
An acetal derivative of camphorquinone represented by