JP5300190B2 - Photocationic curable composition - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a photocationically curable composition with no gelatinization even if stored at high temperatures or room temperature for a long period and also having high curing activity. <P>SOLUTION: The photocationically curable composition comprises (a) a cationically polymerizable monomer, (b) a photoacid generator-based photopolymerization initiator, (c) a phenolic antioxidant, preferably a hindered phenol-based antioxidant, and (d) a salt of an organic acid &le;7 in pKa value with no photoacid-generating ability, preferably an iodonium salt-based photopolymerization initiator. <P>COPYRIGHT: (C)2007,JPO&amp;INPIT

Description

  The present invention relates to a photocationic curable composition that does not gel at high temperatures and can be stored stably for a long period of time.

  In recent years, photocurable resin compositions have been frequently used for adhesion of electric / electronic parts or paints. The photo-curing resin composition cures more quickly than the heat-curing adhesive, and does not heat, so it does not cause thermal damage to the adherend, and it does not harden unless irradiated with light. The setting of the working time until curing is arbitrary, and there are many advantages such that there is no volatilization of a solvent or the like at the time of curing.

  Photocurable resin compositions are broadly classified into radical polymerization types and cationic polymerization types, and radical polymerization types using (meth) acrylic polymerizable compounds with good curability are mainly used. Has been developed and used.

  However, radical polymerization has a drawback that it is inhibited from polymerization by oxygen, and there is a problem that an unpolymerized layer remains in a portion that has been exposed to air during curing. Especially for paint applications with a thin cured film thickness, light irradiation in an inert atmosphere such as nitrogen gas is required.

  The photocurable resin composition is also used for dental applications. Examples include photocurable filling restoration materials called composite resins used for restoration of teeth damaged by caries and fractures, denture base lining materials, hybrid ceramics for crown restoration, etc. It is widely used because of its simple operation. Such a photocurable dental material usually comprises a polymerizable monomer and a polymerization initiator, and further, a composite resin or hybrid ceramic contains a filler. As the polymerizable monomer, a (meth) acrylate radical polymerizable monomer is used because of its good photopolymerizability.

  However, as mentioned above, radically polymerizable monomers are subject to inhibition of polymerization by oxygen when cured in an air atmosphere such as a normal dental clinic or dental laboratory. There is a problem that an unpolymerized layer or a layer having a low degree of polymerization remains on the surface, and the unpolymerized layer is colored or discolored over time. Therefore, generally, after photocuring, the unpolymerized layer on the surface must be removed by polishing or the like. Especially for composite resins that require the same aesthetics as natural teeth, conventional dental composite resins using radically polymerizable monomers have a sufficient surface after polymerization and curing in the oral cavity. Must be polished.

  Furthermore, the (meth) acrylate-based radical polymerizable monomer also has a problem that the polymerization shrinkage is large. That is, when filling and curing a filling restorative material such as a composite resin to the cavity of a tooth that requires restoration, the surface of the filled restorative material is irradiated with light. As a result, a stress that tends to rise from the tooth interface acts, and this tends to cause a gap between the tooth and the filling restorative material. Various dental adhesives that exhibit extremely strong adhesive strength have been proposed to counter this polymerization shrinkage stress, but the dental condition varies from individual to individual or even to the same person, so such dental Even if the adhesive is used, it is not always possible to obtain perfect adhesion to every tooth.

  Therefore, there is a need for a dental material that does not require surface unpolymerization due to oxygen, so that it is not necessary to remove the surface unpolymerized layer. In particular, in the case of a dental composite resin, the polymerization shrinkage is as small as possible. There has been a demand for a material that does not easily generate a gap due to polymerization shrinkage even if force cannot be obtained. Furthermore, since such an adhesive requires a complicated technique for obtaining a high adhesive force, and causes an increase in cost, it has been desired to simplify the adhesive.

  Examples of the polymerizable monomer that does not inhibit the polymerization by oxygen and has a small polymerization shrinkage include cationic polymerizable monomers such as epoxide and vinyl ether. However, since photoradical polymerization initiators such as α-diketone compounds and acylphosphine oxide compounds that are generally used for dentistry cannot polymerize cationically polymerizable monomers, photocationic polymerizable initiators are Necessary.

  Examples of such photocationic polymerization initiators include photoacid generator-based photopolymerization initiators using photoacid generators such as iodonium salts, sulfonium salts, and pyridinium salts. In particular, the iodonium salt-based photopolymerization initiator has high cationic polymerization initiating activity, and thus is useful in dental applications that must be rapidly cured in the oral cavity. There have been reports of actually applying an iodonium salt-based photopolymerization initiator in combination with a cationic polymerizable monomer to dental applications (Patent Documents 1 to 3).

  However, according to the study by the present inventors, the cationic polymerizable composition containing the photoacid generator photopolymerization initiator is relatively early under a temperature condition of about 50 ° C. or even at room temperature. It has been found that there is a problem of gelation during long-term storage. This is easily expected to be caused by the fact that the photoacid generator decomposes thermally by light irradiation to generate an acid in the same manner as it decomposes thermally and generates an acid as well. For this reason, a cationic polysynthetic composition containing a photoacid generator photopolymerization initiator often has to be stored at a low temperature. However, since production lines and the like are often exposed to a temperature of room temperature or higher, the occurrence of gelation may not be suppressed after long-term use.

  In addition, dental materials are often transported by ordinary automobiles or the like when transporting to a dental clinic or the like, but it is not uncommon for the temperature inside the vehicle to exceed 50 ° C. in summer. Further, gelation may occur in the same manner during long-term storage even at temperatures lower than 50 ° C.

  Therefore, when using such a photoacid generator-based photopolymerization initiator as a photocationic polymerization initiator, in order to prevent gelation due to decomposition of the photoacid generator during storage, what is a cationic polymerizable monomer? Separately, a photoacid generator based photopolymerization initiator or a solution thereof is often stored separately, and these two are mixed and irradiated with light before use. However, such an operation tends to cause bubbles to enter due to the mixing operation, and further causes a reduction in strength in a dental material that requires high strength that can withstand occlusal pressure. Furthermore, bacteria enter and propagate from the gaps caused by minute bubbles and become unsanitary, and in the case of a composite resin, it can cause secondary caries.

  On the other hand, by adding a phenol-based radical polymerization inhibitor or antioxidant to a composition containing a cationic polymerizable monomer and an iodonium salt, decomposition of the iodonium salt can be suppressed and gelation can be prevented. It has been reported (Patent Document 4). However, in the study by the present inventors, gelation has not been sufficiently suppressed under the relatively high temperature conditions as described above. It has also been reported that gelation can be suppressed by adding hindered amines that are basic substances to similar compositions (Patent Documents 5 to 7). However, in this case as well, gelation cannot be suppressed under the high temperature conditions.

Japanese Patent Laid-Open No. 10-508067 Special Table 2000-520758 JP-T-2001-520759 JP 2002-69269 A JP 2000-516660 A Special Table 2002-2002655 gazette Special table 2003-292606

  In view of the above background, an object of the present invention is to provide a photocationic curable composition that does not gel even when stored at a high temperature or at room temperature for a long period of time and has high curing activity.

  The present inventors have intensively studied to overcome the above problems. As a result, gelation can be prevented by adding a phenolic antioxidant and a salt of a specific organic acid to a photocationic curable composition containing a photoacid generator-based photopolymerization initiator. In the case where the composition can be cured by polymerization, the present invention has been completed by obtaining knowledge that the composition can be imparted with a property of being cured well.

That is, the present invention relates to a) cationic polymerizable monomer (b) photoacid generator photopolymerization initiator in an amount of 0.001 to 10 parts by mass with respect to 100 parts by mass of (a) cationic polymerizable monomer. (C) The amount of the phenolic antioxidant in the amount of 0.001 to 1 mol of the phenol group in the phenolic antioxidant, relative to 1 mol of the (b) photoacid generator photopolymerization initiator , and (d) no photoacid generating ability, the number of carbon atoms in the portion other than the acidic functional group is 8 to 30, wherein the salts of pKa values of 7 or less of an organic acid (b) a photoacid generator photopolymerization A dental material comprising a photocationic curable composition characterized by comprising 0.001 to 1 mol per mol of initiator .

  According to the present invention, by adding (c) a phenolic antioxidant and (d) the organic salt to a cationically polymerizable monomer containing a photoacid generator-based photopolymerization initiator, It is possible to highly prevent gelation during the storage period. In addition, this photocationic curable composition can be cured satisfactorily without causing curing failure during polymerization curing.

  Therefore, among the applications of various photocationic curable compositions such as adhesives and paints for electrical and electronic parts, there is a risk of exposure to high temperature conditions of 50 ° C. or higher, or storage for a long time at room temperature or higher. It can be suitably used as a product with a fear. In particular, dental materials such as composite resins are not subject to polymerization inhibition by oxygen, and the polymerization shrinkage is small, while the advantages of cationic polymerization can be utilized well, as described above, the problem of gelation during transportation is likely to occur, The photocationic curable composition of the present invention is extremely useful.

The greatest feature of the photocationic curable composition of the present invention is that in a liquid or paste-like composition comprising (a) a cationic polymerizable monomer and (b) a photoacid generator photopolymerization initiator,
It is to mix both (c) a phenolic antioxidant and (d) a salt of an organic acid having a pKa value of 7 or less and not having a photoacid generating ability.

  Thereby, the gelation during the storage period can be highly prevented. On the other hand, in the case of polymerizing and curing, it is possible to cure well without causing curing failure. The reason why the gelation during the storage period is prevented in this way is presumed to be as follows.

  That is, as described above, the main factor that the photocationic curable composition gels during the storage period is that (b) the photoacid generator photopolymerization initiator is thermally decomposed during the storage period, and the acid is removed. It is to occur. On the other hand, the (c) phenol-based antioxidant suppresses the decomposition of the (b) photoacid generator-based photopolymerization initiator. In addition, (c) the acid produced by slightly decomposing only by the action of the phenolic antioxidant is (d) a salt of an organic acid having a pKa value of 7 or less and having no photoacid generating ability. Supplemented by As a result, in the present invention, the synergistic action of these components (c) and (d) significantly reduces the amount of acid present during the storage period of the photocationic curable composition, and (a) the cationically polymerizable monomer. It is presumed that unnecessary polymerization of the monomer does not proceed.

  In the composition of the present invention, the cationic component (a) cationic polymerizable monomer is not particularly limited as long as it is a compound that is polymerized by an acid generated by the decomposition of the photoacid generator, and a known compound is used. Can do.

  Examples of typical cationic polymerizable monomers include vinyl ether compounds, epoxy compounds, oxetane compounds, cyclic ether compounds, bicyclic orthoester compounds, cyclic acetal compounds, bicyclic acetal compounds, and cyclic carbonate compounds. In particular, an oxetane compound and / or an epoxy compound is preferably used because they are easily available, have a small volume shrinkage, and have a fast polymerization reaction.

  Specific examples of the oxetane compound include trimethylene oxide, 3-methyl-3-oxetanylmethanol, 3-ethyl-3-oxetanylmethanol, 3-ethyl-3-phenoxymethyloxetane, 3,3-diethyloxetane, Those having one oxetane ring such as 3-ethyl-3- (2-ethylhexyloxy) oxetane, 1,4-bis (3-ethyl-3-oxetanylmethyloxy) benzene, 4,4′-bis (3 -Ethyl-3-oxetanylmethyloxy) biphenyl, 4,4'-bis (3-ethyl-3-oxetanylmethyloxymethyl) biphenyl, ethylene glycol bis (3-ethyl-3-oxetanylmethyl) ether, diethylene glycol bis (3 -Ethyl-3-oxetanylmethyl) ether, bi (3-ethyl-3-oxetanylmethyl) Jifenoeto, trimethylolpropane tris (3-ethyl-3-oxetanylmethyl) ether, pentaerythritol tetrakis (3-ethyl-3-oxetanylmethyl) ether, or a compound shown below

And compounds having two or more oxetane rings.

  Among the oxetane compounds, those having two or more oxetane rings in one molecule are particularly preferably used from the viewpoint of physical properties of the obtained cured product.

  Also, the epoxy compound is not particularly limited as long as it is a compound capable of cationic polymerization, and known compounds can be used. Specific examples of the epoxy compound include 1,2-epoxypropane, 1,2-epoxybutane, 1,2-epoxypentane, 2,3-epoxypentane, 1,2-epoxyhexane, 1,2-epoxy. Octane, 1,2-epoxydecane, 1,2-epoxydodecane, 1,2-epoxytetradecane, 1,2-epoxyhexadecane, 1,2-epoxyoctadecane, butadiene monooxide, 2-methyl-2-vinyloxirane, 1,2-epoxy-5-hexene, 1,2-epoxy-7-octene, 1,2-epoxy-9-decene, epichlorohydrin, epibromohydrin, glycidol, 2-methylglycidol, methylglydidi Ether, ethyl glycidyl ether, glycidyl propyl ether, butyl glycidyl ether , 2-ethylhexyl glycidyl ether, cyclooctene oxide, cyclohexene oxide, cyclooctene oxide, cyclododecane epoxide, exo-2,3-epoxynorbornene, 4-vinyl-1-cyclohexene-1,2-epoxide, limonene oxide, styrene Oxide, (2,3-epoxypropyl) benzene, phenyl glycidyl ether, benzyl glycidyl ether, glycidyl 2-methylphenyl ether, 4-tert-butylphenyl glycidyl ether, 4-chlorophenyl glycidyl ether, glycidyl 4-methoxyphenyl ether, etc. One having an epoxy functional group, 1,3-butadiene dioxide, 1,2,7,8-diepoxyoctane, ethylene glycol jig Sidyl ether, diethylene glycol diglycidyl ether, triethylene glycol diglycidyl ether, tetraethylene glycol diglycidyl ether, neopentyl glycol diglycidyl ether, 1,3-propanediol diglycidyl ether, 1,4-butanediol diglycidyl ether, 1 , 5-pentanediol diglycidyl ether, 1,6-hexanediol diglycidyl ether, 1,4-cyclohexanemethanol diglycidyl ether, diglycidyl glutarate, diglycidyl adipate, diglycidyl pimelate, diglycidyl suberate, di Glycidyl azelate, diglycidyl sebacate, 2,2-bis [4-glycidyloxyphenyl] propane, 2,2-bis [4-glycidyloxyphe Nyl] hexafluoropropane, 4-vinyl-1-cyclohexene diepoxide, limonene diepoxide, 1,2,5,6-diepoxycyclooctane, 3,4-epoxycyclohexylmethyl-3,4-epoxycyclohexanecarboxylate, Bis (3,4-epoxycyclohexylmethyl) glutarate, bis (3,4-epoxycyclohexylmethyl) adipate, bis (3,4-epoxycyclohexylmethyl) pimelate, bis (3,4-epoxycyclohexylmethyl) suberate, bis ( 3,4-epoxycyclohexylmethyl) zelate, bis (3,4-epoxycyclohexylmethyl) sebacate, 1,4-bis (3,4-epoxycyclohexylmethyloxymethyl) benzene, 1,4-bis (3,4) Epoxy (Rohexylmethyloxymethyl) biphenyl, bis (3,4-epoxycyclohexyl) methane, 2,2-bis (3,4-epoxycyclohexyl) propane, bis (3,4-epoxycyclohexyl) sulfone, methylbis [2- ( 7-oxabicyclo [4.1.0] hept-3-yl) ethyl] phenylsilane, dimethylbis [(7-oxabicyclo [4.1.0] hept-3-yl) methyl] silane, methyl [( 7-oxabicyclo [4.1.0] hept-3-yl) methyl] [2- (7-oxabicyclo [4.1.0] hept-3-yl) ethyl] silane, 1,4-phenylenebis [Dimethyl [2- (7-oxabicyclo [4.1.0] hept-3-yl) ethyl]] silane, 1,2-ethylenebis [dimethyl [2- (7-oxa Cyclo [4.1.0] hept-3-yl) ethyl]] silane, dimethyl [2- (7-oxabicyclo [4.1.0] hept-3-yl) ethyl] silane, 1,3-bis [2- (7-Oxabicyclo [4.1.0] hept-3-yl) ethyl] -1,1,3,3-tetramethyldisiloxane, 2,5-bicyclo [2.2.1] heptylene bis [Dimethyl [2- (7-oxabicyclo [4.1.0] hept-3-yl) ethyl]] silane, 1,6-hexylenebis [dimethyl [2- (7-oxabicyclo [4.1. 0] hept-3-yl) ethyl]] silane having two epoxy functional groups, or glycerol triglycidyl ether, trimethylolpropane triglycidyl ether, pentaerythritol triglycidyl ether, Pentaerythritol tetraglycidyl ether, dipentaerythritol hexaglycidyl ether, and

And those having three or more epoxy functional groups.

  Among the above epoxy compounds, those having two or more epoxy functional groups in one molecule are particularly preferably used from the viewpoint of physical properties of the obtained cured product.

Specific examples of the cationically polymerizable monomer other than the oxetane compound and the epoxy compound include tetrahydrofuran, oxepane and the like as the cyclic ether compound, and bicycloorthoester, spiroorthoester as the bicyclic orthoester compound, Examples of the cyclic acetal compounds such as spiro ortho carbonate include 1,3,5-trioxane, 1,3-dioxolane, oxepane, 1,3-dioxepane, 4-methyl-1,3-dioxepane, 1,3,6- Examples of the bicyclic acetal compound such as trioxacyclooctane include 2,6-dioxabicyclo [2.2.1] heptane, 2,7-dioxabicyclo [2.2.1] heptane, 6,8- Dioxabicyclo [3.2.1] octane and the like are cyclic carbonate compounds such as ethylene carbonate. Over DOO, these cationically polymerizable to trimethylene carbonate and the like monomers can be used singly or in combinations of two or more. In particular, A mole of an oxetane compound having an average of a oxetane functional group of 1 molecule and B mole of an epoxy compound having an average of b epoxy functional groups of 1 molecule are mixed, and (a × A): (b × What was prepared so that B) may be in the range of 90:10 to 45:55 is preferable in that the curing rate is high and the polymerization is not easily inhibited by moisture.

  In the curable composition of the present invention, (b) the photoacid generator-based photopolymerization initiator is excited by light irradiation to decompose the photoacid generator, and as a result, generates an acid, which is polymerized. It is a compound that becomes a starting species and initiates cationic polymerization. Examples of such photoacid generator polymerization initiators include iodonium salt photopolymerization initiators, sulfonium salt photopolymerization initiators, pyridinium salt photopolymerization initiators, and trihalomethyl-S-triazine photopolymerization initiators. Is mentioned.

  The compound excited by light irradiation may be a photoacid generator itself that decomposes to generate an acid, but the photoacid generator usually has many compounds that do not absorb in the near-ultraviolet to visible range, and is polymerized. In order to excite the reaction, a special light source is often required. Therefore, it is preferable that it is a photoinitiator which combined as a sensitizer the compound which has absorption in a near ultraviolet-visible region, and is excited by light irradiation, and causes the decomposition | disassembly of a photo-acid generator. Furthermore, in order to increase the efficiency of decomposition of the photoacid generator by light irradiation, a compound other than the sensitizing compound may be used in combination.

  Among these photoacid generator-based polymerization initiators, iodonium salt-based photopolymerization initiators and sulfonium salt-based photopolymerization initiators are preferable because of high polymerization activity, and iodonium salt-based photopolymerization initiators are more preferable. As such an iodonium salt-based photopolymerization initiator, for example, a condensed polycyclic aromatic compound as a sensitizing compound as disclosed in JP-A No. 2004-149487 and JP-A No. 2004-196949 A photopolymerization initiator using an α-dicarbonyl compound as a sensitizing compound as disclosed in JP-A-10-508067, disclosed in JP-A-2004-196775 And a photopolymerization initiator that uses both an oxidized photoradical generator and a condensed polycyclic aromatic compound. Furthermore, JP-A-11-199681, JP-A-2000-7716, JP-A-2001-81290, JP-A-11-322952, JP-A-11-130945, JP-A-2001-520758, etc. The iodonium salt-based photopolymerization initiator described in 1) can be used. Hereinafter, such an iodonium salt-based photopolymerization initiator will be described in more detail.

  As the iodonium salt that is a component of the iodonium salt-based photopolymerization initiator blended in the photocationic curable composition of the present invention, any conventionally known one can be used without any limitation. Specific examples include diphenyliodonium, bis (p-chlorophenyl) iodonium, ditolyliodonium, bis (p-tert-butylphenyl) iodonium, p-isopropylphenyl-p-methylphenyliodonium, bis (m-nitrophenyl). ) Iodonium, p-tert-butylphenylphenyliodonium, p-methoxyphenylphenyliodonium, bis (p-methoxyphenyl) iodonium, p-octyloxyphenylphenyliodonium, p-phenoxyphenylphenyliodonium, bis (p-dodecylphenyl) Cations such as iodonium, chloride, bromide, p-toluenesulfonate, trifluoromethanesulfonate, tetrafluoroborate, tetrakispentafluoropheny Examples thereof include diaryl iodonium salt compounds composed of anions such as ruborate, tetrakispentafluorophenyl gallate, hexafluorophosphate, hexafluoroarsenate and hexafluoroantimonate.

  Among these, p-toluenesulfonate, trifluoromethanesulfonate, tetrafluoroborate, tetrakispentafluorophenylborate, tetrakispentafluorophenylgallate, hexafluorophosphate, from the viewpoint of solubility in the cationic polymerizable monomer, A compound having hexafluoroarsenate or hexafluoroantimonate as an anion can be preferably used, and hexafluoroantimonate, tetrakispentafluorophenylborate, tetrakispenta are from the point of low anion nucleophilicity and high polymerization rate. A compound having fluorophenyl gallate as an anion can be preferably used. Furthermore, tetrakispentafluorophenyl borate can be most suitably used because of its lower toxicity derived from anions.

  Moreover, the sulfonium salt compound which is a component of the sulfonium salt photopolymerization initiator compounded in the photocationic curable composition of the present invention includes, as specific examples, triphenylsulfonium, p-tolyldiphenylsulfonium, p-tert- Chloride such as butylphenyldiphenylsulfonium, diphenyl-4-phenylthiophenylsulfonium, bromide, p-toluenesulfonate, trifluoromethanesulfonate, tetrafluoroborate, tetrakispentafluorophenylborate, tetrakispentafluorophenylgallate, hexafluorophosphate , Hexafluoroarsenate, and hexafluoroantimonate salts.

  These photoacid generators may be used alone or in combination of two or more as required. The amount of these photoacid generators used is not particularly limited as long as the polymerization can be initiated by light irradiation, but an appropriate rate of polymerization progress and various physical properties of the resulting cured product (for example, weather resistance) In general, 0.001 to 10 parts by mass, preferably 0.05 to 5 parts by mass is used with respect to 100 parts by mass of the cationic polymerizable monomer described above. Good.

  Examples of the sensitizer used in combination with the photoacid generator include condensed polycyclic aromatic compounds such as acridine dyes, benzoflavin dyes, anthracene and perylene, phenothiazines, diaryl ketone compounds, α-diketone compounds or A coumarin compound etc. are mentioned. These may be used alone or in appropriate combination of two or more.

  Among the sensitizers, a condensed polycyclic aromatic compound is preferable in terms of good polymerization activity, and a structure in which a saturated carbon atom having at least one hydrogen atom is bonded to the condensed polycyclic aromatic ring. Condensed polycyclic aromatic compounds having are preferred.

  Specific examples of such condensed polycyclic aromatic compounds having a structure in which a saturated carbon atom having at least one hydrogen atom is bonded to a condensed polycyclic aromatic ring include 1-methylnaphthalene and 1-ethylnaphthalene. 1,4-dimethylnaphthalene, acenaphthene, 1,2,3,4-tetrahydrophenanthrene, 1,2,3,4-tetrahydroanthracene, benzo [f] phthalane, benzo [g] chroman, benzo [g] isochroman, N-methylbenzo [f] indoline, N-methylbenzo [f] isoindoline, phenalene, 4,5-dimethylphenanthrene, 1,8-dimethylphenanthrene, acephenanthrene, 1-methylanthracene, 9-methylanthracene, 9-ethylanthracene , 9-cyclohexylanthracene, 9,10-dimethyl Luanthracene, 9,10-diethylanthracene, 9,10-dicyclohexylanthracene, 9-methoxymethylanthracene, 9- (1-methoxyethyl) anthracene, 9-hexyloxymethylanthracene, 9,10-dimethoxymethylanthracene, 9- Dimethoxymethylanthracene, 9-phenylmethylanthracene, 9- (1-naphthyl) methylanthracene, 9-hydroxymethylanthracene, 9- (1-hydroxyethyl) anthracene, 9,10-dihydroxymethylanthracene, 9-acetoxymethylanthracene 9- (1-acetoxyethyl) anthracene, 9,10-diacetoxymethylanthracene, 9-benzoyloxymethylanthracene, 9,10-dibenzoyloxymethylanthracene, 9 -Ethylthiomethylanthracene, 9- (1-ethylthioethyl) anthracene, 9,10-bis (ethylthiomethyl) anthracene, 9-mercaptomethylanthracene, 9- (1-mercaptoethyl) anthracene, 9,10-bis (Mercaptomethyl) anthracene, 9-ethylthiomethyl-10-methylanthracene, 9-methyl-10-phenylanthracene, 9-methyl-10-vinylanthracene, 9-allylanthracene, 9,10-diallylanthracene, 9-chloro Methyl anthracene, 9-bromomethylanthracene, 9-iodomethylanthracene, 9- (1-chloroethyl) anthracene, 9- (1-bromoethyl) anthracene, 9- (1-iodoethyl) anthracene, 9,10-dichloromethylanthracene 9,10-dibromomethylanthracene, 9,10-diiodomethylanthracene, 9-chloro-10-methylanthracene, 9-chloro-10-ethylanthracene, 9-bromo-10-methylanthracene, 9-bromo-10 -Ethylanthracene, 9-iodo-10-methylanthracene, 9-iodo-10-ethylanthracene, 9-methyl-10-dimethylaminoanthracene, acanthrene, 7,12-dimethylbenz (a) anthracene, 7,12- Dimethoxymethylbenz (a) anthracene, 5,12-dimethylnaphthacene, collanthrene, 3-methylcholanthrene, 7-methylbenzo (a) pyrene, 3,4,9,10-tetramethylperylene, 3,4,9, 10-tetrakis (hydroxymethyl) perylene, bio Nsuren, Isoviolanthrone Ren, 5,12-dimethyl-naphthacene, 6,13-dimethyl pentacene, 8,13- dimethyl penta Fen, 5,16- dimethyl hexamethylene Sen, 9,14- dimethyl hexa Fen and the like.

  Examples of condensed polycyclic aromatic compounds other than the above include naphthalene, phenanthrene, anthracene, naphthacene, benz [a] anthracene, pyrene, perylene, chrysene.

  Among these condensed polycyclic aromatic compounds, taking into account the use of the dental curable composition of the present invention in the oral cavity, absorption is visible in the visible range so that polymerization can be excited with visible light. Preferably, the compound has a maximum absorption in the visible range. Further, these condensed polycyclic aromatic compounds may be used in combination with a plurality of compounds as necessary.

  The addition amount of the sensitizer such as the condensed polycyclic aromatic compound also varies depending on the other components to be combined and the type of the polymerizable monomer, but usually the sensitizer is used with respect to 1 mol of the photoacid generator. The compound is 0.001 to 20 mol, preferably 0.005 to 10 mol.

  Further, it is preferable to add an oxidized photoradical generator in addition to the condensed polycyclic aromatic compound as a sensitizer because the polymerization activity is further improved. An oxidized photoradical generator refers to a photoradical generator in which a mechanism for generating active radical species by excitation by light irradiation is based on an oxidizing agent action (reducing itself). For example: • A compound that generates a radical when excited by light irradiation, and generates a radical by extracting hydrogen from the hydrogen donor by excitation. • A so-called hydrogen abstraction type type. A type that generates radicals (self-cleaving radical generator), and then the radicals extract electrons from the electron donor, and those that are excited by light irradiation to directly extract electrons from the electron donor and become radicals, etc. Can be mentioned.

  These oxidation type photo radical generators are not particularly limited, and known compounds may be used. However, in terms of higher polymerization activity when irradiated with light compared to other compounds, hydrogen abstraction type light radical generators may be used. A radical generator is preferred, and among them, a diaryl ketone compound, an α-diketone compound or a ketocoumarin compound is particularly preferred.

  Specific examples of the diaryl ketone compound include 4,4-bis (dimethylamino) benzophenone, 9-fluorenone, 3,4-benzo-9-fluorenone, 2-dimethylamino-9-fluorenone, and 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-dimethylanthraquinone, 2-tert-butylanthraquinone, 1-chloroanthraquinone, 2-chloroanthraquinone 1,5-dichloroanthraquinone, 1,2-dimethoxyanthraquinone, 1,2-diacetoxy-anthraquinone, 5,12-naphthacenequinone, 6,13-pentacenequinone, xanthone, thioxanthone, 2,4-dimethylthioxanthone, 2,4 -Diethylthioxanthone, 2-chlorothioxanthone, 9 (10H) -acridone, 9-methyl-9 (10H) -acridone, dibenzosuberenone and the like can be mentioned.

  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, etc. are mentioned.

  Examples of ketocoumarin compounds include 3-benzoylcoumarin, 3- (4-methoxybenzoyl) coumarin, 3-benzoyl-7-methoxycoumarin, 3- (4-methoxybenzoyl) 7-methoxy-3-coumarin, and 3-acetyl- Examples thereof include 7-dimethylaminocoumarin, 3-benzoyl-7-dimethylaminocoumarin, 3,3′-coumarinoketone, 3,3′-bis (7-diethylaminocoumarino) ketone, and the like.

  These oxidized photoradical generators can be used alone or in admixture of two or more. Moreover, although the addition amount varies depending on the other components to be combined and the kind of the polymerizable monomer, the photoradical generator is usually 0.001 to 20 mol relative to 1 mol of the photoacid generator described above. It is preferable that it is 005-10 mol.

  In addition to the above components, in order to promote the decomposition of the photoacid generator, electron donating compounds such as p-dimethoxybenzene, 1,2,4-trimethoxybenzene, phenylalanine, 4-dimethylaminobenzoic acid ester, etc. May be included.

  Next, in the composition of the present invention, conventionally known (c) phenolic antioxidants can be used without any limitation. For example, 4-methoxyphenol, hydroquinone and the like can also be used favorably.

  Since the effect of preventing gelation is highly exhibited in a small amount, it is more preferable to use one belonging to a hindered phenol antioxidant. Here, the hindered phenolic antioxidant is a compound in which at least one of the two aromatic carbons adjacent to the aromatic carbon to which the phenolic hydroxyl group is bonded is substituted with a secondary alkyl group or a tertiary alkyl group. Say what you are.

  Examples of the secondary alkyl group include 3 to 10 carbon atoms such as isopropyl group, 1-methylethyl group, 1-ethylpropyl group, cyclohexyl group, 1-ethylhexyl group, and 1-ethyloctyl group, and more preferably 3 To 6 are preferable, and as the tertiary alkyl group, t-butyl group, 2,2-dimethylethyl group, 2,2-dimethylbutyl group, 2-methyl-2-ethylpropyl group, 1- Those having 4 to 10 carbon atoms, more preferably 4 to 6 carbon atoms such as methylcyclohexyl group and 2,2-dimethyloctyl group are preferable.

  As the hindered phenol-based antioxidant, those known as antioxidants for resins as described above can be used. Among these, those in which at least one of the two aromatic carbons adjacent to the aromatic carbon to which the phenolic hydroxyl group is bonded are substituted with a tertiary alkyl group are preferable in that a more excellent effect can be obtained. . Specific examples of such hindered phenol antioxidants include 2,6-di-t-butylphenol, 2,4-di-t-butylphenol, 2-t-butyl-4,6-dimethylphenol, 2,6-di-tert-butyl-4-methylphenol, 2,4,6-tri-tert-butylphenol, n-octadecyl-3- (3,5-di-tert-butyl-4-hydroxyphenyl) propionate Or a compound represented by the following formula

Etc. Furthermore, among these hindered phenolic antioxidants, those in which both of the two aromatic carbons adjacent to the aromatic carbon to which the phenolic hydroxyl group is bonded are substituted with a tertiary alkyl group are most preferred. Used.

  These phenolic antioxidants may be used in combination with a plurality of compounds as necessary.

  The addition amount of the phenolic antioxidant also varies depending on the other components to be combined and the type of the cationic polymerizable monomer, but the effect of the present invention can be sufficiently obtained, and the cured product physical properties after curing are hardly adversely affected. In general, the phenol group is 0.001 to 1 mol, and more preferably 0.005 to 0.8 mol, with respect to 1 mol of the photoacid generator.

  Further, in the composition of the present invention, (d) organic acid salts that do not have photoacid generation ability and that originate from an organic acid having a pKa value of 7 or less are used without limitation. Here, having no photoacid generating ability is distinguished from salts belonging to the photoacid generator used in component (b), specifically, when irradiated with light having a wavelength longer than 200 nm. In which the quantum yield of acid generation is less than 0.001. The quantum yield of acid generation can be measured by the method described in J Polym Sci Part A: Polym Chem 2003, 41, 2570, for example.

  Moreover, when the pKa value of the organic acid constituting these organic acid salts is 7 or less, the salts can be stably present in the cationic polymerizable monomer. When the pKa value of this organic acid exceeds 7, the basicity of the corresponding organic acid salt becomes strong and there is a possibility that it reacts with the cationic polymerizable monomer. When it is difficult to measure the pKa value of an organic acid, a 0.1M aqueous solution or dispersion of an organic acid salt is prepared, and if the pH value of the aqueous solution or dispersion is 10 or less, ( d) It is sufficient as a salt of an organic acid.

  In the case where the pKa value is derived from an inorganic acid having a value of 7 or less, the dispersibility in the cationic polymerizable monomer is remarkably lowered, and the physical properties such as the bending strength of the cured product are lowered. It is.

  Examples of such organic acids include trifluoroacetylacetone derivatives, carboxylic acids, sulfonic acids, sulfinic acids, phosphonic acids, alkyl sulfuric acids, monoalkyl phosphoric acids, and dialkyl phosphoric acids. Among these, organic acids having a pKa value of 6 or less are preferable, and organic acids having a pKa value of 5 or less are more preferable.

  When the organic acid constituting the salt of the organic acid is a dibasic acid such as a monoalkyl phosphoric acid or a plurality of basic acids higher than that, the pKa value based on the first dissociation is 7 or less. (D) can be used as salts of organic acids.

  Furthermore, salts of carboxylic acids, alkylsulfuric acids, sulfonic acids, or monoalkylphosphoric acids are preferred and salts of alkylsulfuric acids are more preferred because they are easily available and the effects of the present invention are high. In the salt of alkyl sulfates, the alkyl group may have a substituent such as a hydroxyl group, an alkyl group, an aryloxy group, or a halogen, and further an ester group, a carbonate group, an amide group in the middle of the main chain of the group. , A urethane group, an ether group or the like may be interposed.

  On the other hand, the organic acid ion part of the organic acid and the cation part that forms a salt include metal ions such as alkali metal ions, alkaline earth metal ions, aluminum ions, and zinc ions, or ammonium ions, monoalkylammonium ions, and dialkylammonium ions. Organic cations such as ions, trialkylammonium ions, tetraalkylammonium ions, tetraalkylphosphonium ions, and trialkylsulfonium ions can be used.

  As a more preferable metal ion, an alkali metal ion or an alkaline earth metal ion is more preferable, an alkali metal salt is particularly preferable, and a sodium salt is most preferable because it is easily available and the effect of the present invention is high.

  On the other hand, as a more preferable organic cation, a trialkylammonium ion and a tetraalkylammonium ion are preferable because the effect of the present invention is high, and a tetraalkylammonium having no hydrogen atom on a nitrogen atom, which often shows weak acidity. Ions are particularly preferable because the effects of the present invention can be exhibited to a higher degree. Known tetraalkylammonium ions can be used without any limitation. As the alkyl group, those having 1 to 15 carbon atoms, more preferably those having 3 to 10 carbon atoms are suitable. For example, tetramethylammonium ion, tetraethylammonium ion, tetrapropylammonium ion, tetrabutylammonium ion, tetrapentylammonium ion, tetrahexylammonium ion, dodecyltrimethylammonium ion and the like can be mentioned.

  Among these cation moieties that form salts with organic acid ions, tetraalkylammonium ions are optimal because they can be uniformly dissolved in the polymerizable monomer and the effects of the present invention are particularly prominent. .

  These organic acid salts can fully exert their effects even if they are not uniformly dissolved in the cationic polymerizable monomer described above, but are soluble and dispersible in the cationic polymerizable monomer. In order to improve the above, a salt of an organic acid having 6 or more, more preferably 8 to 30 carbon atoms in a portion other than the acidic functional group in the organic acid is preferable. More preferred are organic acid salts that can be used as an anionic surfactant.

  As specific examples of such organic acid salts, as the carboxylate ion part of the carboxylate,

As alkyl sulfate ion part of alkyl sulfate

As sulfonate ion part of sulfonate

As monoalkyl phosphate ion part of monoalkyl phosphate

Alkali metal salts such as lithium salts, sodium salts and potassium salts, or alkaline earth metal salts such as magnesium salts, calcium salts and barium salts, and tetraalkylammonium salts such as tetraethylammonium salts and tetrabutylammonium salts. It is done.

  These organic acid salts may be used in combination with a plurality of compounds as required.

  The addition amount of the organic acid salt also varies depending on the other components to be combined and the type of the cationic polymerizable monomer, but the effect of the present invention can be sufficiently obtained and the cured product physical properties after curing are hardly adversely affected. Usually, the salt of the organic acid is 0.001 to 1 mol, and more preferably 0.005 to 0.8 mol with respect to 1 mol of the above-described photoacid generator.

  In addition to the above-mentioned components, the photocationic curable composition of the present invention may contain other blends within the range of types and blending amounts that do not impair the effects of the present invention, depending on the use of the composition. Ingredients may be included.

  For example, when using the curable composition of this invention as a dental filling restoration material, it is preferable that the filler (filler) is mix | blended.

As the filler, it is possible to blend any of organic, inorganic or organic-inorganic composite fillers blended into dental restoration materials,
Examples of organic fillers include polymethyl methacrylate, polyethyl methacrylate, methyl methacrylate-ethyl methacrylate copolymer, cross-linked polymethyl methacrylate, cross-linked polyethyl methacrylate, ethylene-vinyl acetate copolymer, styrene-butadiene copolymer, Examples thereof include particles made of an organic polymer such as acrylonitrile-styrene copolymer and acrylonitrile-butadiene-styrene copolymer.

  Specific examples of the inorganic filler include inorganic particles such as quartz, silica, alumina, silica titania, silica zirconia, lanthanum glass, barium glass, and strontium glass. Examples of the organic-inorganic composite filler include granular organic-inorganic composite particles obtained by mixing these inorganic particles and a polymerizable monomer in advance, forming a paste, polymerizing, and pulverizing. In addition, X-ray contrast property can also be provided by using what contains heavy metals, such as a zirconia, as an inorganic filler.

  The particle diameter and shape of these fillers are not particularly limited, and spherical or irregular particles having an average particle diameter of 0.01 μm to 100 μm, which are generally used as dental materials, can be appropriately used depending on the purpose. That's fine. Further, the refractive index of these fillers is not particularly limited, and those in the range of 1.4 to 1.7 which the fillers of general dental curable compositions have can be used without limitation.

  The blending amount when the filler is blended with the photocationic curable composition of the present invention is not particularly limited as long as the composition is in a paste-like range, but when used as a dental filling restorative material, An inorganic and / or organic-inorganic composite filler is employed, and this is preferably 50 to 1500 parts by mass, and preferably 70 to 1000 parts by mass with respect to 100 parts by mass of the cationic polymerizable monomer.

  Furthermore, these fillers such as inorganic fillers and organic-inorganic composite fillers may be used alone, or a plurality of fillers having different materials, particle sizes, shapes, etc. may be used in combination. In terms of excellent mechanical properties after curing, it is particularly preferable to mainly use an inorganic filler when used as a dental filling / restoring material.

  Moreover, it is also possible to mix | blend the addition polymerization type radical polymerizable monomer, such as a (meth) acrylate type monomer, with the photocationic curable composition of this invention as needed. By blending the radically polymerizable monomer, the apparent curing time can be further shortened. However, since addition polymerization type radical polymerization is inhibited by polymerization due to oxygen, it is not preferable to add it in a large amount.

  When the radical polymerizable monomer is blended, the blending amount is preferably 30% by mass or less with respect to a total of 100% by mass of the cationic polymerizable monomer and the radical polymerizable monomer. % Or less is preferable.

  Specific examples of such radical polymerizable monomers include methyl (meth) acrylate, glycidyl (meth) acrylate, 2-cyanomethyl (meth) acrylate, polyethylene glycol mono (meth) acrylate, and allyl (meth) acrylate. 2-hydroxyethyl mono (meth) acrylate, ethylene glycol di (meth) acrylate, diethylene glycol di (meth) acrylate, triethylene glycol di (meth) acrylate, nonaethylene glycol di (meth) acrylate, propylene glycol di (meth) Acrylate, dipropylene glycol di (meth) acrylate, 2,2-bis [4- (meth) acryloyloxyethoxyphenyl] propane, 2,2-bis [4- (meth) acryloyloxyethoxye Xylphenyl] propane, 2,2-bis {4- [3- (meth) acryloyloxy-2-hydroxypropoxy] phenyl} propane, 1,4-butanediol di (meth) acrylate, 1,3-hexanediol di ( And (meth) acrylate monomers such as (meth) acrylate, urethane di (meth) acrylate, and trimethylolpropane di (meth) acrylate.

  When the curable composition of the present invention is used in a dental composition, in addition to the above-mentioned components, other components known as a compounding component of a dental curable composition, particularly a dental filling restorative material, are blended. May be.

  Examples of such components include known additives such as ultraviolet absorbers, dyes, antistatic agents, pigments, fragrances, organic solvents and thickeners.

  The photocationic curable composition of the present invention is not limited to the above-described dental use and can be used as an adhesive, a paint, and the like, but is particularly suitable as a dental filling / restoration material.

  The method for producing the curable composition of the present invention is not particularly limited, and a known method for producing a curable composition may be appropriately employed. Specifically, in a dark place, the cationic polymerizable monomer, photoacid generator photopolymerization initiator, phenolic antioxidant, organic acid salts, and necessary constituting the curable composition of the present invention A predetermined amount of other blending components blended according to the conditions may be weighed and mixed to form a paste. The photocationic curable composition of the present invention thus produced is stored under light shielding until use.

  As a means for curing the photocationic curable composition of the present invention, a known polymerization means may be appropriately employed according to the polymerization initiation mechanism of the photoacid generator-based photopolymerization initiator used. There are no restrictions on arc irradiation, xenon lamps, metal halide lamps, tungsten lamps, fluorescent lamps, irradiation with light sources such as sunlight, helium cadmium lasers, argon lasers, heating using a heating polymerizer, or a combination of these. Used without. In the case of polymerization by light irradiation, the irradiation time varies depending on the wavelength of the light source, the intensity, the shape and material of the cured body, and therefore may be determined in advance by preliminary experiments. It is preferable to adjust the blending ratio of various components so that it is in the range of about 5 to 60 seconds.

  EXAMPLES Hereinafter, the present invention will be specifically described with reference to examples, but the present invention is not limited to the examples. The names and structures of the compounds used in the text and in the examples are shown below.

  1. Cationic polymerizable monomer

2. 2. Photoacid generator photopolymerization initiator 2-1. Iodonium salt

  2-2. Sulfonium salt

  2-3. Sensitizer

2. DMBE ethyl p-dimethylaminobenzoate Phenolic antioxidant

  4). Organic acid salts that are not photoacid generators

  None of the above organic acid salts generated an acid even when irradiated with light having the maximum absorption wavelength of the compound, and the quantum yield could not be measured.

  In addition, the pKa values of the organic acids constituting each are 4 to 5 for SDD and TEDS, -3 to -2 for SDS and TBDS, -4 to -1 for SBS, and the first dissociation for DPDS. The pKa value based on is 0 to 1, and the pKa value based on the second dissociation is 5 to 6.

  5. Other ingredients: Hindered amine stabilizer

６．充填材
球状フィラー：３−グリシジルオキシプロピルトリメトキシシランで処理した球状シリカ（粒径０．２〜２μｍ）を用いた。

6). Filler Spherical filler: Spherical silica (particle size 0.2-2 μm) treated with 3-glycidyloxypropyltrimethoxysilane was used.

  Moreover, the evaluation method of the various physical properties in an Example and a comparative example is shown below.

(1) Curability (1-1) When a filler is not included 0.9 g is placed in a polypropylene container having an inner diameter of 1.6 cm and a depth of 1.1 cm, and the composition prepared in each example and comparative example is cured. The thick film was 4 mm. Next, using a dental light irradiator (TOKUSO POWER LITE, manufactured by Tokuyama Corporation), light irradiation was performed for 1 minute at an irradiation distance of 0.5 cm. At this time, the case where the entire composition after irradiation was sufficiently cured was rated as “◯”, and the cured body was soft, or had an uncured part, or was not lowered at all.

(1-2) Including Filler The compositions prepared in each Example and Comparative Example were taken out on kneaded paper and irradiated with light in the same manner as in the case of not containing the filler. At this time, the composition after light irradiation was sufficiently cured and the cured body was not easily broken by hand, and the case where it was easily cracked or not cured at all was rated as x.

(2) Storage days until gelation (2-1) When filler is not included The compositions prepared in each Example and Comparative Example were stored in a thermostat at 50 ° C. under light shielding conditions. The curable composition was taken out from the thermostatic apparatus every other day, allowed to cool to room temperature in the dark, and then the properties of the curable composition were observed. At this time, compared with a composition consisting only of the same cationically polymerizable monomer (not containing a polymerization initiator), the fluidity is greatly lost and the viscosity is increased, or it does not flow and becomes a jelly. The number of days was defined as the number of days until gelation.

(2-2) When containing a filler The compositions prepared in each Example and Comparative Example were stored in a thermostatic apparatus at 50 ° C. under light shielding conditions. The curable composition was taken out from the thermostatic apparatus every other day, allowed to cool to room temperature in the dark, and then the properties of the curable composition were examined with a metal spatula. The number of days until gelation was defined as the number of days that could not be formed with a metal spatula and the filling material was cracked or hardened and could not be broken with a metal spatula.

Production Example 1 (Synthesis of TBDS)
5.76 g (0.02 mol) of SDS and 5.56 g (0.02 mol) of tetrabutylammonium chloride were dissolved in 100 g of distilled water and stirred for 1 hour. While further stirring, 200 g acetone was added little by little, and then stirred for 1 hour. After stirring, the reaction solution was filtered, the filtrate was concentrated with a rotary evaporator, and water and acetone were distilled off. The obtained concentrate was dissolved in 100 ml of acetone, insoluble matter was removed by filtration, and the obtained filtrate was again concentrated by a rotary evaporator and further dried overnight under vacuum. TBDS (9.7 g, yield 95.5%) was obtained as a viscous liquid. The elemental analysis results and ¹ H-NMR measurement results are shown below.
Elemental analysis value (calculated value in parentheses) C; 65.82 (66.22), H; 12.43 (12.11), N; 2.55 (2.76)
_{^{1 H-NMR (500MHz, CDCl}} 3, ppm) 4.01 (t, 2H, - CH 2 -O -), 3.29 (t, 8H, - CH 2 -N -), 1.68-1. _{62 (m, 8H, - CH} 2 -CH 2 -N -), 1.49-1.41 (m, 8H, - CH 2 -CH 2 -CH 2 -N -), 1.37-1.26 _{(m, 20H, CH 3 -} (CH 2) 10 -CH 2 -O -), 1.01 (t, 12H, CH 3 - (CH 2) 3 -N -), 0.88 (t, 3H, _{CH 3 - (CH 2) 11} -O-)
Example 1
With respect to 100 parts by mass of a cationic polymerizable monomer composed of 60 parts by mass of OX-1 and 40 parts by mass of EP-1, 1.5 parts by mass of IMDPI as a photoacid generator-based photopolymerization initiator, 0. 2 parts by weight of DMBAn and 0.6 parts by weight of CQ were added as phenolic antioxidants, 0.1 part by weight of BHT and 0.1 parts by weight of SDD as organic acid salts were added and stirred for 6 hours. .

  The curability of this composition and the storage days until gelation were evaluated. The results are shown in Table 1.

Examples 2-7, Comparative Examples 1-11
In Example 1, a composition was prepared in the same manner as in Example 1 except that the phenolic antioxidant to be blended and the salt of the organic acid were changed as described in Table 1, until the curability and gelation. The preservation days were evaluated. The results are also shown in Table 1.

  As shown in Table 1 above, when both the phenolic antioxidant and the salt of the organic acid were blended, the curability was excellent, and the storage days until gelation were extremely long even when stored at 50 ° C. . On the other hand, when only one of phenolic antioxidants or organic acid salts is blended (Comparative Examples 2 to 9), the number of storage days until gelation is compared to the case where neither is blended (Comparative Example 1). However, it was much shorter than in each example, and sufficient storage stability was not obtained.

  Comparative Example 10 is a blend of a hindered amine stabilizer, and Comparative Example 11 is a blend of both a phenolic antioxidant and a hindered amine stabilizer. It was difficult to obtain a storage period as long as when both salts were added.

Examples 8 and 9, Comparative Examples 12 and 13
In Example 1, a composition was prepared in the same manner as in Example 1 except that the photoacid generator photopolymerization initiator to be blended was changed as described in Table 2, and the curability and gelation were The preservation days were evaluated. In addition, the same photoacid generator photopolymerization initiator was used, and a composition containing no phenolic antioxidant or organic acid salt was also prepared, and the curability and storage days until gelation were similarly evaluated ( Comparative Examples 12 and 13). The results are also shown in Table 2.

Examples 10-16, Comparative Examples 14-24
Photoacid generator-based photopolymerization composed of 2 parts by weight of TPS and 1 part by weight of DMBAn with respect to 100 parts by weight of cationically polymerizable monomer composed of 60 parts by weight of OX-1 and 40 parts by weight of EP-1. A composition was prepared in the same manner as in Example 1 except that an initiator was used and the phenolic antioxidant, organic acid salts, and other components were changed as described in Table 3, and the curability and gel were changed. The number of days until storage was evaluated. The results are also shown in Table 3.

  As shown in Table 3 above, even when a sulfonium salt polymerization initiator is used as a photoacid generator photopolymerization initiator, by blending both a phenolic antioxidant and an organic acid salt, Excellent storage stability could be obtained.

Example 17
In Example 1, in the ratio shown in Table 4, except that cation polymerizable monomers, iodonium salt photopolymerization initiators, phenolic inhibitors and organic acid salts were used, liquids were obtained in the same manner as in Example 1. A composition was prepared. To this liquid composition, spherical silica is added as a filler so as to have a content of 70% by mass, mixed in an agate mortar, the mixture is degassed under vacuum to remove bubbles, and the filler is contained. A paste-like composition was obtained.

  About this composition, sclerosis | hardenability and the storage days until gelatinization were evaluated. The results are also shown in Table 4.

Comparative Examples 25-29
In Example 17, a paste-like composition containing the filler was prepared in the same manner as in Example 17 except that the filler was blended in the proportions shown in Table 4, and its curability and storage until gelation was achieved. The number of days was evaluated. The results are also shown in Table 4.

  As shown in Table 4 above, even when a filler is included, by blending both the phenolic antioxidant and the salt of the organic acid, only one of them is blended (Comparative Examples 26 and 27). In addition, much better storage stability could be obtained. Comparative Example 28 is a blend of a hindered amine stabilizer, and Comparative Example 29 is a blend of both a phenolic antioxidant and a hindered amine stabilizer. It was difficult to obtain the stability as excellent as when both salts were blended.

Claims (3)

(A) Cationic polymerizable monomer (b) Photoacid generator photopolymerization initiator is 0.001 to 10 parts by mass with respect to 100 parts by mass of ( a) cationic polymerizable monomer. (C) the amount of the phenolic antioxidant in the phenolic antioxidant is 0.001 to 1 mol , and (d) light with respect to 1 mol of the (b) photoacid generator photopolymerization initiator. A salt of an organic acid having no acid generating ability and having a carbon number of 8 to 30 in a portion other than the acidic functional group and having a pKa value of 7 or less is added to 1 mol of the photoacid generator photopolymerization initiator (b). A dental material comprising a photocationic curable composition, characterized in that it comprises 0.001 to 1 mol . (C) Dental material which consists of a photocationic curable composition of Claim 1 whose phenolic antioxidant is a hindered phenolic antioxidant. (B) The photoacid generator photopolymerization initiator is an iodonium salt photopolymerization initiator, The dental material which consists of a photocationic curable composition of Claim 1 or 2.