JP2007015946A - Cationically curable composition for dental use - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a cationically curable composition for dental use, subject to no polymerization inhibition attributable to oxygen, rapidly curable even at room temperature, giving sufficient cured product's physical properties, extremely slight in contraction concomitant with its polymerization, and having high moisture resistance. <P>SOLUTION: The cationically curable composition for dental use comprises (I) an oxetane compound having in the molecule at least two oxetane groups, (II) an epoxy compound of such a specific structure as to be represented by the general formula(a) (wherein, R<SP>3</SP>to R<SP>20</SP>are each H, a halogen atom, alkoxy or alkyl; R<SP>21</SP>and R<SP>22</SP>are each H or a 1-10C hydrocarbon group, wherein the number of the carbon atoms of R<SP>21</SP>and R<SP>22</SP>totals ≥2; and n is an integer of 0 or 1 ) and (III) a cationic polymerization initiator. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a dental curable composition. More preferably, the present invention relates to a cationically curable composition suitably used as a dental filling / restoration material.

  In the restoration of a tooth damaged by caries or fracture, a photocurable composite filling restoration material called a composite resin is generally used because of its easy operation and high aesthetics. Such a composite resin is usually composed of a polymerizable monomer, a filler (filler), and a polymerization initiator, and the polymerizable monomer is a (meth) acrylate radical polymerization due to its good photopolymerizability. Sex monomers are used.

  However, ordinary radical polymerizable monomers are of the addition polymerization type and have a problem that they are inherently high in polymerization shrinkage due to their curing mechanism and are more susceptible to polymerization inhibition by oxygen. .

  When filling and curing a filling restorative material such as a composite resin to the cavity of a tooth that requires restoration, it is necessary to irradiate light from the surface of the filled restorative material, that is, from a position far from the tooth. There is. However, due to the shrinkage accompanying the polymerization described above, a stress that tends to rise from the interface with the tooth substance 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.

  In addition, the composite resin using a (meth) acrylate radical polymerizable monomer is subjected to polymerization inhibition by oxygen as described above, and therefore there is an unpolymerized layer or a low polymerized layer on the surface of the cured body, and after curing, When the surface is not polished, there arises a problem of coloring or discoloration of the cured body over time.

  Accordingly, there is a need for a dental composite resin that has as little polymerization shrinkage as possible, is less likely to cause gaps due to polymerization shrinkage even if sufficient adhesive strength is not obtained depending on the state of the teeth, and is less susceptible to polymerization inhibition by oxygen in the air. It was. Furthermore, since the adhesive as described above requires a complicated procedure for obtaining a high adhesive force, and increases the cost, it has been desired to simplify the adhesive.

  On the other hand, as a general technique for reducing polymerization shrinkage, there is a technique for increasing the mass (functional group equivalent; g / mol) per 1 mol of a polymerizable functional group in a polymerizable monomer. That is, in the case of a monomer having two (meth) acrylate groups in one molecule, the polymerization shrinkage decreases as the monomer molecular weight increases. However, when the functional group of the monomer is remarkably increased, the viscosity of the monomer is increased, which makes it difficult to handle, and the crosslinking density is lowered, resulting in a problem that the physical properties of the cured product are remarkably lowered.

  On the other hand, it is known that the ring-opening polymerization monomer has a smaller polymerization shrinkage than the addition polymerization monomer. Among them, a cationic ring-opening polymerizable monomer that can be polymerized by an acid is known as a monomer that is hardly subject to inhibition of polymerization by oxygen. Examples of such cationic ring-opening polymerizable monomers include epoxy compounds, oxetane compounds, tetrahydrofuran, bicycloorthoester compounds, spiroorthoester compounds, cyclic carbonate compounds, and spiroorthocarbonates. Among these, bicycloorthoester compounds, spiroorthoester compounds, cyclic carbonate compounds, or spiroorthocarbonates are known as polymerizable monomers that do not shrink or expand during polymerization (Non-patent Document 1). However, these non-shrinkable or expandable cationic ring-opening polymerizable monomers are extremely slow to polymerize and require heating conditions to be fully cured, so they must be polymerized and cured in the oral cavity. It is not suitable for dental use, which is often the case.

  On the other hand, although the epoxy compound does not have non-shrinkage or expansibility, polymerization shrinkage can be reduced as compared with a (meth) acrylate monomer. Further, the polymerization rate is higher than that of the non-shrinkable or expandable ring-opening polymerizable monomer, and it is cured even at room temperature. In particular, alicyclic epoxy compounds represented by cyclohexene oxide have high curing activity.

  On the other hand, oxetane compounds have been reported to have a faster polymerization reaction than epoxy compounds. Furthermore, it has been reported that by adding an epoxy compound to oxetane, the polymerization rate is improved as compared with the case where each is used alone (Non-patent Document 2).

  For the above reasons, the use of alicyclic epoxy or oxetane has been proposed as a component of a dental curable composition with less polymerization shrinkage and preferable room temperature curing (Patent Documents 1 to 14).

  However, even when conventional epoxies or oxetane compounds are used, the polymerization shrinkage rate or curing rate is still not at a satisfactory level for dental use. In addition, similar alicyclic epoxies with excellent dimensional stability have been reported (Patent Document 12), and the alicyclic epoxy group is combined with an oxetane compound having only one oxetane group in the molecule. (Patent Document 13), however, in a specific combination thereof, the obtained cured product has a low crosslinking density and the like, and only the cured product properties are greatly inferior. Further, the problem when the functional group equivalent of the epoxy or oxetane compound is increased for the purpose of reducing polymerization shrinkage is also as described above.

Japanese National Patent Publication No. 10-508067 JP-A-11-130945 JP-T-2001-520758 JP-T-2001-520759 Japanese Patent Laid-Open No. 8-245578 JP-T-2001-513117 JP-T-2002-526391 JP-A-48-29899 JP 58-172387 A JP 2004-99467 A JP 2004-285125 A JP 2005-68303 A JP-A-2005-75907 JP-T-2002-526391 Radtech Study Group, “Current Status and Prospects of UV / EV Curing Technology”, CMC Publishing Co., Ltd., December 27, 2002, p. 45-48 J. et al. Polym. Sci. Part A: Polym. Chem. , 31, 199 (1993)

  In the background described above, the present invention is a cationically curable dental composition that is not subject to polymerization inhibition by oxygen, and quickly cures at room temperature, has sufficient cured product properties, and is capable of further polymerization. An object of the present invention is to provide a dental cationic curable composition having extremely low shrinkage and high moisture resistance.

  As a result of diligent research to solve the above-mentioned problems, the present invention combines a specific oxetane compound with an epoxy compound having a specific structure, so that there is no polymerization inhibition due to oxygen, and it can be cured quickly and sufficiently cured. As a result of finding that it has physical properties and the shrinkage caused by polymerization is extremely reduced, and further studies were conducted, the present invention was completed.

That is, the present invention
(I) an oxetane compound having at least two oxetane groups in the molecule,
(II) The carbon atom at the 3-position or 4-position of the cyclohexene oxide group which may have a substituent is represented by the following formula (1):

(Wherein, R ¹ and R ² are a hydrogen atom or a hydrocarbon group which may have a substituent group having a carbon number of 1 to 13, the total number of carbon atoms in R ¹ and R ² is 2 or more .)
An epoxy compound having at least 2 units of a cyclohexene oxide ring-containing unit to which a carbon atom constituting a hydrocarbon ring of a 5-membered ring to 8-membered ring is bonded, or (III) cationic polymerization initiation It is a dental cationic curable composition comprising an agent.

  The dental cation-curable composition of the present invention is not only a conventional dental material using a (meth) acrylate radical polymerizable monomer, but also a conventionally known epoxy compound or oxetane. Compared to the case of using a compound, the polymerization shrinkage is extremely small, and there is no polymerization inhibition by oxygen.

  In addition, the curing time is short, the patient is not burdened even when used in the oral cavity, the mechanical strength is high, and it is extremely useful industrially.

The cationic curable composition of the present invention is a cationic polymerizable monomer.
(I) an oxetane compound having at least two oxetane groups in the molecule;
(II) The carbon atom at the 3-position or 4-position of the cyclohexene oxide group which may have a substituent is represented by the following formula (1):

(Wherein, R ¹ and R ² are a hydrogen atom or a hydrocarbon group which may have a substituent group having a carbon number of 1 to 13, the total number of carbon atoms in R ¹ and R ² is 2 or more .)
Or an epoxy compound having at least 2 units of a cyclohexene oxide ring-containing unit to which a carbon atom constituting a 5- to 8-membered hydrocarbon ring is bonded.

  Here, the oxetane compound (I) is particularly limited as long as it is a compound that has two or more oxetane groups in the molecule, preferably 2 to 8 oxetane groups, and is capable of cationic polymerization. There are no known compounds. Since this oxetane compound has two or more oxetane groups in the molecule, when used in combination with an epoxy compound (II) described later, excellent cured product properties relating to mechanical strength such as high bending strength can be obtained. . When there is only one oxetane group in the molecule, the resulting cationic curable composition is inferior in physical properties of the cured product.

  The oxetane group is represented by the following formula (3)

(In the formula, m is an integer of 1 to 6.)
Is a four-membered ether (oxetane ring) group. In the above formula (3), a hydrogen atom bonded to one or two bonds at the 3-position of the oxetane ring is substituted, and other groups are not substituted, and a group to which a hydrogen atom is bonded is preferable. The oxetane group is represented by the following formula (4)

(In the formula, R ²³ is a hydrogen atom or an alkyl group having 1 to 10 carbon atoms.)
What is contained as group shown by these is preferable. Examples of the alkyl group having 1 to 10 carbon atoms include alkyl groups having 1 to 10 carbon atoms such as methyl group, ethyl group, propyl group, butyl group, pentyl group, hexyl group, heptyl group, octyl group, nonyl group, and decyl group. Among them, an alkyl group having 1 to 3 carbon atoms, particularly an ethyl group is preferable.

  Of these oxetane compounds, a compound having an ester bond in the molecule is obtained by using the acid used as the polymerization initiator when the cation curable composition obtained using the oxetane compound is exposed to wet conditions during the cation curing. As a result, the ester bond may be hydrolyzed to lower the cured product properties. Therefore, it is preferable to use one having no such ester bond.

  Specific examples of the oxetane compound include bis [1-ethyl (3-oxetanyl)] methyl ether, 1,2-bis [(3-ethyloxetane-3-yl) methyloxy] ethane, and 1,3-bis. [(3-ethyloxetane-3-yl) methyloxy] propane, 1,4-bis [(3-ethyloxetane-3-yl) methyloxy] butane, 1,5-bis [(3-ethyloxetane-3 -Yl) methyloxy] pentane, 1,6-bis [(3-ethyloxetane-3-yl) methyloxy] hexane, 1,7-bis [(3-ethyloxetane-3-yl) methyloxy] heptane, 1,8-bis [(3-ethyloxetane-3-yl) methyloxy] octane, 1,4-bis [(3-ethyloxetane-3-yl) methyloxymethyl] benzene, 4,4′-bis [ ( 3-ethyloxetane-3-yl) methyloxymethyl] biphenyl, 2,2′-bis [(3-ethyloxetane-3-yl) methyloxymethyl] biphenyl, diethylene glycol bis [(3-ethyloxetane-3-yl) ) Methyl] ether, tritylene glycol bis [(3-ethyloxetane-3-yl) methyl] ether, tetraethylene glycol bis [(3-ethyloxetane-3-yl) methyl] ether, trimethylolpropane tris [(3 -Ethyloxetane-3-yl) methyl] ether, pentaerythritol tetrakis [(3-ethyloxetane-3-yl) methyl] ether, or a compound shown below

Is mentioned.

  Furthermore, as an oxetane group, following formula (2)

(In the formula, Ar is an aryl group which may have a substituent, and R ²³ is a hydrogen atom or an alkyl group having 1 to 10 carbon atoms.)
When the compound having the oxetane group is used in combination with an epoxy compound (II) described later, the curing rate is higher and the polymerization shrinkage is particularly preferable. Examples of the aryl group include a phenyl group and a naphthyl group. Examples of the substituent include a methyl group, an ethyl group, a propyl group, a butyl group, a pentyl group, a hexyl group, a heptyl group, an octyl group, a nonyl group, a decyl group, etc., an alkyl group having 1 to 10 carbon atoms; a cyclohexyl group, a cyclopentyl group A cyclohexyl group having 3 to 8 carbon atoms such as a halogen atom such as a chlorine atom, a bromine atom, a fluorine atom or an iodine atom; an alkoxy group having 1 to 10 carbon atoms such as a methoxy group, an ethoxy group or a butoxy group; a phenyl group or a naphthyl group An aryl group such as a group; an aralkyl group such as a benzyl group; and the like, among which an alkyl group having 1 to 3 carbon atoms such as a methyl group and an ethyl group is preferable. The number of these substituents substituted on the aryl group is preferably 4 or less, more preferably 2 or less.

  As a compound having such an oxetane group,

Etc. Of these, the following general formula (b)

(Wherein R ²⁴ is an oxygen atom or a divalent hydrocarbon group having 1 to 20 carbon atoms, and n is an integer of 0 or 1)
The compound shown by is especially preferable. Here, as a C1-C20 bivalent hydrocarbon group, the linear or branched divalent aliphatic hydrocarbon which what was illustrated as a compound which has the oxetane group of the said Formula (2) has Groups and aromatic hydrocarbon groups. Preferred R ²⁴ is most preferably an oxygen atom or a divalent alkylene group having 1 to 5 carbon atoms.

  In the present invention, these oxetane compounds may be used in combination.

  In the composition of the present invention for dental use, those having a functional group equivalent of 150 to 500 g / mol are preferably used from the viewpoint of volatility and operability of the composition, and more preferably liquid at room temperature. Available to:

  Next, as the (II) epoxy compound, the carbon atom at the 3-position or 4-position of the cyclohexene oxide group which may have a substituent may be represented by the following formula (1):

(Wherein, R ¹ and R ² are a hydrogen atom or a hydrocarbon group which may have a substituent group having a carbon number of 1 to 13, the total number of carbon atoms in R ¹ and R ² is 2 or more .)
Or a unit having a cyclohexene oxide ring-containing unit to which a carbon atom constituting a 5- to 8-membered hydrocarbon ring is bonded, preferably 2 to 8 units. Can be used without limitation.

  The central carbon atom of the group represented by the above formula (1) as well as the individual carbon atoms constituting the hydrocarbon ring having 5 to 8 members are densely packed in the state of the surrounding linking groups. In this state, one of the bonds of the carbon atom in these states is bonded to the 3- or 4-position carbon atom of the cyclohexene oxide group, so that the cyclohexene oxide ring-containing unit has a configuration of the cyclohexene oxide ring. The seat is fixed. As a result, the volume occupied by the cyclohexene oxide ring-containing unit is smaller than a group containing a normal cyclohexene oxide group.

  On the other hand, when the epoxy ring of the cyclohexene oxide ring is opened, the cyclohexene oxide ring-containing unit can take a relatively free conformation, and thus the occupied volume increases. As a result, the cationic curable composition obtained by combining the epoxy compound having the structural unit with the above-mentioned (I) oxetane compound has a polymerization shrinkage even when the functional group equivalent of the epoxy group is small. The rate is remarkably small, and the cation cures very quickly. Moreover, since these epoxy compounds have two or more cyclohexene oxide ring-containing units in the molecule, like the oxetane compounds described above, they have excellent cured body properties such as mechanical strength.

  In the above epoxy compound, as the other substituent that the cyclohexene oxide group may have, those described as the substituent of the aryl group in the group of the formula (2) can be preferably employed, and in particular, a methyl group Alkyl groups having 1 to 3 carbon atoms such as are suitable. The number of these substituents substituted on the cyclohexene oxide group is preferably 4 or less, more preferably 2 or less.

The hydrocarbon group of the formula (1) R ¹ and carbon atoms of R ² 1 to 13 having a group represented by a methyl group, an ethyl group, a propyl group, a butyl group, a pentyl group, a hexyl group, a heptyl Group, octyl group, nonyl group, decyl group and other alkyl groups; cyclohexyl group, cyclopentyl and other cyclohexyl groups; phenyl group, naphthyl group and other aryl groups; benzyl group and other aralkyl groups. Examples of the substituent include halogen atoms such as chlorine atom, bromine atom, fluorine atom and iodine atom, and oxygen atom. In addition, the hydrocarbon group of R ¹ and R ² is a group having 1 to 13 carbon atoms and having an oxygen atom as a substituent, and may be a cyclohexene oxide group.

The total number of carbon atoms of R ¹ and R ² needs to be 2 or more in order to make the group of formula (1) bulky and exert the effects of the present invention. it is preferred that 2 to 10 in order to remarkably exhibited, the total number of carbon atoms when the either one of R ¹ and R ² are hydrogen atoms is more preferably 3 to 10.

The hydrocarbon groups for R ¹ and R ² may be bonded to each other to form a ring.

  (II) A cyclohexene oxide ring-containing unit in which a group represented by the above formula (1) is bonded to a carbon atom at the 3-position or 4-position of the cyclohexene oxide group which may have such a substituent among epoxy compounds. As a compound having at least 2 units, for example,

Etc.

  On the other hand, the hydrocarbon ring having a carbon atom bonded to the 3- or 4-position carbon atom of the cyclohexene oxide group includes a 5-membered ring to an 8-membered ring, and more preferably 5-membered rings and 6-membered rings. Can be mentioned. These may have two or more, and preferably two, condensed hydrocarbon rings. Specific examples include alicyclic hydrocarbons such as cyclopentane ring, cyclopentene ring, cyclopentene oxide ring, cyclohexane ring, cyclohexene ring, and cyclohexene oxide ring, and aromatic hydrocarbons such as benzene ring and naphthalene ring.

  (II) Among the epoxy compounds, a carbon atom constituting a 5- to 8-membered hydrocarbon ring is bonded to the 3- or 4-position carbon atom of the cyclohexene oxide group which may have such a substituent. Examples of the compound having at least two cyclohexene oxide ring-containing units include:

Is mentioned.

It is more preferable that the carbon atom of the cyclohexene oxide group to which the surrounding carbon atoms are bonded is the 4-position of the cyclohexene oxide group from the viewpoint of ease of production. Further, these epoxy compounds, which do not have an ester bond in the molecule, like the oxetane compound described above, are more preferable because the physical properties of the cured product are not lowered due to moisture absorption during curing.
Etc.

  Among the above epoxy compounds, the following general formula (a)

(In the formula, R ^{3 to} R ²⁰ are each a hydrogen atom, a halogen atom, an alkoxy group, or an alkyl group, which may be the same or different, and R ²¹ and R ²² are a hydrogen atom or a carbon number of 1 to 10). And the total carbon number of R ²¹ and R ²² is 2 or more, and m is an integer of 0 or 1)
The compounds represented by the formula are particularly prominent because they are easily available and have a small effect on polymerization shrinkage, and are particularly preferably used. In particular,

The compound shown by these is mentioned.

  In the present invention, these epoxy compounds may be used in combination.

  In the present invention, the blending ratio of (I) oxetane compound and (II) epoxy compound is not particularly limited, but the influence of moisture on the polymerization reaction can be greatly reduced, even under high humidity conditions such as in the oral cavity. Since the oxetane compound has an average of a oxetane functional group per molecule and the epoxy compound has an average of b epoxy functional groups per molecule because it can be cured, (a × A): (b × B) Is preferably in a range of 90:10 to 45:55 by blending A mole of the oxetane compound and B mole of the epoxy compound. Furthermore, (a × A) :( b × B) is preferable because the curing rate becomes faster by making the ratio of the epoxy functional group smaller than 45:55. Furthermore, in the present invention, since the polymerization shrinkage can be further reduced, (a × A) :( b × B) is preferably in the range of 80:20 to 45:55, more preferably 70:30 to 45: A range of 55.

  The epoxy curable composition of the present invention may be blended with other epoxy compounds as long as the effects of the present invention are not impaired, but the polymerization shrinkage increases as the proportion in the curable composition increases. Therefore, when the total of all cationically polymerizable functional groups in the cationic curable composition is 100 parts by mass, the other epoxy compound is preferably 30 parts by mass or less.

  Among these other epoxy compounds, an epoxy compound having two or more alicyclic epoxy groups is preferable because of its high curing activity. Specific examples of such an epoxy compound include 1,2,5,6-diepoxycyclooctane, 3,4-epoxycyclohexylmethyl-3,4-epoxycyclohexanecarboxylate, and bis (3,4-epoxycyclohexyl). Methyl) 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-epoxycyclohexylmethyloxymethyl) biphenyl, Methyl bis 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-oxabicyclo [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- L) ethyl] -1,1,3,3-tetramethyldisiloxane, 2,5-bicyclo [2.2.1] heptylenebis [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, or a compound shown below

Etc. A plurality of these epoxy compounds may be used in combination.

  Moreover, it is also possible to mix | blend an addition polymerization type radical polymerizable monomer, such as a (meth) acrylate type monomer, as needed. However, addition polymerization type radical polymerizability is inhibited by polymerization due to oxygen, so it is not preferable to add too much. 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.

  Next, the (III) cationic polymerization initiator blended in the cationic curable composition of the present invention will be described.

  The (I) cationic polymerization initiator is not particularly limited, and any known cationic polymerization initiator may be used. As such cationic polymerization initiators, Lewis acids or Bronsted acids, or compounds that generate Lewis acids or Bronsted acids by heating or light irradiation are known. It is particularly preferable to employ a so-called photoacid generator that generates a Lewis acid or a Bronsted acid by light irradiation because it can be polymerized quickly in an environment such as the oral cavity.

  Examples of the photoacid generator include diaryliodonium salt compounds, sulfonium salt compounds, sulfonic acid ester compounds, pyridinium salt compounds, and halomethyl-substituted S-triazine conductors.

  Among these, diaryliodonium salt compounds and sulfonium salt compounds are excellent in that the polymerization activity is particularly high. Specific examples of diaryliodonium salt compounds 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 Cations such as (p-dodecylphenyl) iodonium, chloride, bromide, p-toluenesulfonate, trifluoromethanesulfonate, tetrafluoroborate And diaryl iodonium salt compounds comprising anions such as tetrakispentafluorophenylborate, tetrakispentafluorophenyl gallate, hexafluorophosphate, hexafluoroarsenate, hexafluoroantimonate.

  Among these, p-toluene sulfonate, trifluoromethane sulfonate, tetrafluoroborate, tetrakispentafluorophenylborate, tetrakispentafluorophenyl gallate, hexafluorophosphate, hexagonal from the viewpoint of solubility in polymerizable monomers. A compound having fluoroarsenate or hexafluoroantimonate as an anion can be suitably used, and it has low nucleophilicity, and can be stably stored as a mixture with a polymerizable monomer without light irradiation. A compound having fluoroantimonate, tetrakispentafluorophenylborate or tetrakispentafluorophenylgallate as an anion can be preferably used.

  Examples of the sulfonium salt compounds include dimethylphenacylsulfonium, dimethylbenzylsulfonium, dimethyl-4-hydroxyphenylsulfonium, dimethyl-4-hydroxynaphthylsulfonium, dimethyl-4,7-dihydroxynaphthylsulfonium, dimethyl-4,8- Cations such as dihydroxynaphthylsulfonium, triphenylsulfonium, p-tolyldiphenylsulfonium, p-tert-butylphenyldiphenylsulfonium, diphenyl-4-phenylthiophenylsulfonium, chloride, bromide, p-toluenesulfonate, trifluoromethanesulfonate , Tetrafluoroborate, tetrakispentafluorophenylborate, tetrakispentafluorophenylgallate, hexaful Examples thereof include sulfonium salt compounds composed of anions such as orophosphate, hexafluoroarsenate, hexafluoroantimonate and the like.

  These photoacid generators may be used singly or in combination as needed. 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. .

  The photoacid generator as described above usually has many compounds that do not absorb in the near ultraviolet to visible range, and a special light source is often required to excite the polymerization reaction. Therefore, it is preferable that a compound having absorption in the near ultraviolet to visible region is further added as a sensitizer in addition to the photoacid generator.

  Examples of the compound used as such a sensitizer include acridine dyes, benzoflavine dyes, condensed polycyclic aromatic compounds such as anthracene and perylene, and phenothiazine.

  Among these 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.

  As the condensed polycyclic aromatic compounds other than the above, naphthalene, phenanthrene, anthracene, naphthacene, benz [a] anthracene, pyrene, perylene and the like are preferably used.

  Among these condensed polycyclic aromatic compounds, a compound having absorption in the visible range is preferable and a compound having maximum absorption in the visible range, which can excite polymerization with visible light in consideration of harm to the living body. Is more preferable. Further, these condensed polycyclic aromatic compounds may be used in combination with a plurality of compounds as necessary.

  The addition amount of the condensed polycyclic aromatic compound also varies depending on the other components to be combined and the kind of the polymerizable monomer, but the amount of the condensed polycyclic aromatic compound is usually 0 with respect to 1 mol of the above-mentioned photoacid generator. 0.001 to 20 mol, and preferably 0.005 to 10 mol.

  Furthermore, it is preferable to add an oxidized photoradical generator in addition to the condensed polycyclic aromatic compound because the polymerization activity is further improved. An oxidized photoradical generator is a compound that generates radicals when excited by light irradiation, and is a so-called hydrogen abstraction type radical generator that generates radicals by extracting hydrogen from a hydrogen donor by excitation. Generates radicals by causing self-cleavage (self-cleaving radical generator), and then the radicals withdrawing electrons from the electron donor, and radicals that are excited by light irradiation and withdraw electrons directly from the electron donor. The photoradical generator is a mechanism that generates active radical species by excitation by light irradiation, such as the following. 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 polymerization initiator and the polymerizable monomer, the dental cation curable composition of the present invention can be blended with other components known as a compounding component of the dental curable composition.

  A typical other compounding component is a filler (filler). By blending a filler with the dental cationic curable composition of the present invention, polymerization shrinkage can be further reduced. In addition, by using a filler, it is possible to improve the operability of the curable composition before curing, or to improve the mechanical properties after curing, especially useful as a filling restoration material for dental use. Will be expensive.

  When a filler is blended with the dental cation-curable composition of the present invention, the type and blending amount of the filler may be appropriately set according to the use of the composition. For example, when the dental cation curable composition of the present invention is used as a filling restorative material, a known filler may be blended as a filler for the dental filling restorative material.

  More specifically, inorganic fillers such as amorphous silica, silica-titania, silica-zirconia, silica-titania-barium oxide, quartz, alumina and the like can be mentioned. Furthermore, a small amount of Group I metal oxides are present in the inorganic oxide particles for the purpose of easily obtaining dense inorganic oxide particles when these inorganic oxide particles are fired at a high temperature. It is also possible to use mixed oxide particles. For dental use, an inorganic filler of a composite oxide containing silica and zirconia as main constituents has X-ray contrast properties, so that it is particularly preferably used.

  The particle diameter and shape of these inorganic 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, are appropriately used depending on the purpose. do it. 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 compositions have can be used without limitation. Among them, in order to obtain higher surface smoothness and wear resistance, it is preferable to use a spherical or substantially spherical inorganic powder and / or an aggregate thereof. Note that the term “substantially spherical” as used herein refers to an average homogeneity obtained by taking a photograph of an inorganic filler with a scanning electron microscope and gradually decreasing the particle diameter in the direction perpendicular to the maximum particle diameter observed in the unit field of view at the maximum diameter. Says that the degree is 0.6 or more.

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

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

  Moreover, an organic-inorganic composite filler can be suitably used for the purpose of achieving both a higher filler filling rate and good operability. The organic-inorganic composite filler is obtained by polymerizing and curing a polymerizable monomer and a polymerization curable composition containing an inorganic filler as main components, and is obtained by pulverization. An inorganic composite filler is used without any limitation.

  The blending amount when the filler is blended with the cationic curable composition of the present invention is not particularly limited, but when used as a dental filling restorative material, it is 50 to 100 parts by weight with respect to 100 parts by weight of the polymerizable monomer. 1500 parts by mass, preferably 70 to 1000 parts by mass is preferred. Furthermore, these fillers such as inorganic filler and organic-inorganic composite filler may be used alone or in combination with a plurality of different types of materials, particle sizes, shapes, etc. In view of excellent physical properties, it is particularly preferable to use an inorganic filler alone or in combination with an inorganic filler and an organic-inorganic composite filler.

  Furthermore, the dental cation-curable composition of the present invention includes a polymerization inhibitor, a stabilizer such as an antioxidant and an ultraviolet absorber, other dyes, an antistatic agent, a pigment, as long as the effects of the present invention are not impaired. Known additives such as fragrances, organic solvents and thickeners may be blended.

  In particular, when an iodonium salt-based initiator is blended as a polymerization initiator in the dental curable composition of the present invention, the curable composition can be stored under relatively high conditions of about 50 ° C. or at room temperature for a long period of time. It is preferable that a binderd phenol and a hindered amine are blended because gelation of the product can be suppressed. Here, hindered phenols are those 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 by a secondary alkyl group or a tertiary alkyl group. Show. Among them, the one in which both of the two aromatic carbons adjacent to the aromatic carbon to which the phenolic hydroxyl group is bonded is substituted with a tertiary alkyl group is most preferably used. Such compounds include 2,6-di-t-butylphenol, 2,6-di-t-butyl-4-methylphenol, 2,4,6-tri-t-butylphenol, n-octadecyl-3- ( 3,5-di-t-butyl-4-hydroxyphenyl) propionate, tetrakis [methylene-3- (3,5-di-t-butyl-4-hydroxyphenyl) propionate] methane, tris (3,5-di -T-butyl-4-hydroxybenzyl) isocyanurate and the like. These hindered phenols may be used in combination with a plurality of compounds as necessary. The amount of these hindered phenols to be added varies depending on other components to be combined. Usually, the amount of the hindered phenol group is 0.001 to 1 mol per 1 mol of the diaryl iodonium salt described above, and 0.005 to 0.001. It is preferably 8 moles.

  The hindered amines are secondary or tertiary aliphatic amine compounds, and at least two of the alkyl groups bonded to the nitrogen atom constituting the amine are secondary or tertiary alkyl groups. Indicates. As such hindered amines, known compounds can be used without particular limitation, and for example, hindered amines known as light stabilizers for resins can be used. Among these, pyrrolidines, piperidines, and piperazines that are chemically stable cyclic amines are preferable, and piperidines are more preferable from the viewpoint of easy availability. Specific examples of such hindered amines include 2,6-dimethylpiperidine, N-methyl-2,6-dimethylpiperidine, N-methyl-2,6-dimethylpiperidin-4-one, and N-methyl-4. -Hydroxy-2,6-dimethylpiperidine, 2,2,6,6-tetramethylpiperidine, N-methyl-2,2,6,6-tetramethylpiperidine, N-methyl-2,2,6,6- Tetramethylpiperidin-4-one, N-methyl-4-hydroxy-2,2,6,6-tetramethylpiperidine, bis (2,2,6,6-tetramethyl-4-piperidinyl) sebacate, bis (N -Methyl-2,2,6,6-tetramethyl-4-piperidinyl) sebacate, tetrakis (2,2,6,6-tetramethyl-4-piperidinyl) -1,2,3,4-butanetetraca Ruboxylate, tetrakis (N-methyl-2,2,6,6-tetramethyl-4-piperidinyl) -1,2,3,4-butanetetracarboxylate, tetrakis (2,2,6,6-tetramethyl- 4-piperidinyl) -1,2,3,4-butanetetracarboxylate, poly [(6- (1,1,3,3-tetramethylbutyl) imino-1,3,5-triazi / 2,4- Diyl] [(2,2,6,6-tetramethyl-4-piperidinyl) imino] hexamethylene (2,2,6,6-tetramethyl-4-piperidinyl) iminol, dimethyl-1- (2 -Hydroxyethyl) 4-hydroxy-2,2,6,6-tetramethyl-4-piperidine polycondensate, etc. These hindered amines may be used in combination with a plurality of compounds as required. There.

  Although the amount of hindered amines to be added varies depending on other components to be combined, the hindered amino group is usually 0.001 to 1 mol per 1 mol of the iodonium salt in the previous term in that it hardly affects the physical properties of the cured product after curing. Mol, and preferably 0.005 to 0.8 mol.

  The dental cationic polymerizable composition of the present invention is particularly preferably used as the dental filling / restoration material as described above, but is not limited thereto, and other uses such as a dental adhesive and a denture base material. Can also be used.

  The manufacturing method of the dental cation-curable composition of the present invention is not particularly limited, and a known manufacturing method may be adopted as appropriate. Specifically, a predetermined amount of a cationic polymerization initiator, a cationic polymerizable monomer, and other blending components blended as necessary, which constitute the dental cation-curable composition of the present invention, are weighed out. What is necessary is just to mix.

  The packaging form of the dental cationic curable composition of the present invention is not particularly limited, and may be appropriately determined in consideration of its purpose and storage stability. For example, when a photocationic polymerization initiator is blended as a cationic polymerization initiator, all the components constituting the dental cation-curable composition of the present invention may be made into one package in a light-shielded state. On the other hand, if a component that can start cationic polymerization at room temperature without light irradiation is used as a polymerization initiator, it can be divided into two or more packages to prevent polymerization and curing during storage. A form in which both are mixed immediately before use is preferred.

  As a means for curing the dental cationic curable composition of the present invention, a known polymerization means may be appropriately employed according to the polymerization initiation mechanism of the used cationic polymerization initiator. Specifically, a carbon arc, a xenon lamp, A metal halide lamp, a tungsten lamp, a fluorescent lamp, light irradiation with a light source such as sunlight, helium cadmium laser, and argon laser, heating using a heating polymerizer, or a combination of these is used without any limitation. 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. Similarly, the heating time and heating temperature may be determined in advance by preliminary experiments.

EXAMPLES Hereinafter, the present invention will be specifically described with reference to examples, but the present invention is not limited to the examples. The abbreviations of the compounds used in the text and in the examples are as follows. In addition, the inside of () shows a functional group equivalent.
1. (I) Oxetane compound which is an essential component of the present invention

2. Oxetane compound which is not an essential component of the present invention

3. (Ii) Epoxy compound which is an essential component of the present invention

4). Epoxy compound which is not an essential component of the present invention

5. Radical polymerizable compound

6). Photoacid generator

7). Fused polycyclic aromatic compounds

8). 8. Oxidized photoradical generator CQ: camphorquinone Other DMBE: ethyl 4-dimethylaminoethyl benzoate Further, preparation methods of various compositions and evaluation methods of physical properties in Examples and Comparative Examples are shown below.

(1) Preparation of Matrix In the dark, a polymerization initiator was added to the polymerizable monomer, and the mixture was stirred and dissolved until uniform to prepare the matrices A to O. Table 1 shows the composition.

(2) Surface treatment of inorganic filler 20 g of spherical silica-zirconia (particle diameter 0.2 μm) was suspended in 80 ml of hydrochloric acid adjusted to pH 4.0, and 3-ethyl-3- (3-triethoxysilyl was stirred. Propoxy) methyloxetane 1.2 g was added dropwise. After stirring for 1 hour, water was distilled off with an evaporator, and the obtained solid was pulverized with a mortar and then dried at 80 ° C. under reduced pressure for 15 hours. After drying, the obtained powder was used as an inorganic filler PF1, and stored in a desiccator using silica gel as a desiccant.

  Similarly, an inorganic filler PF2 was treated with 1 g of 3-methacryloxypropyltrimethoxysilane.

(3) Preparation of organic / inorganic composite filler For 100 parts by mass of 60 parts by mass of Bis-GMA and 40 parts by weight of 3G, 0.5 parts by mass of azobisisobutyronitrile (hereinafter referred to as a polymerization initiator) in advance. , AIBN), 25 parts by mass and 75 parts by mass of PF2 were mixed in an agate mortar to form a paste. This was polymerized by heating at 95 ° C. under a nitrogen atmosphere for 1 hour. The polymerized cured product was pulverized using a vibration ball mill, and this was used as an organic-inorganic composite filler HF1 (average particle size: 20 μm).

(4) Preparation of paste The inorganic filler PF1 and the organic-inorganic composite filler HF1 were mixed so that the mass ratio was 40:60, and 82 parts by mass of this mixture and 18 parts by mass of matrix A were mixed in an agate mortar. Under a vacuum, defoaming was performed to remove bubbles, and a paste A was obtained.

  Similarly, paste B was obtained from matrix B, pastes G to I were obtained from matrices G to I, and pastes K and L were obtained from matrices K and L.

(5) Surface Unpolymerization A matrix was applied to the bottom of a polytetrafluoroethylene mold having 6 mmφ × 0.3 mm holes using a Pasteur pipette. Similarly, light irradiation was performed for 60 seconds with a dental visible light irradiator (Tokuyama Dental Co., Powerlight) from a distance of about 5 mm on the upper surface of the composition liquid, and the composition was photocured. An object having a stickiness on the irradiated surface of the cured body was rated as x, and an object having no stickiness was marked as ◯.

(6) Curing time of composition not containing filler (matrix) 0.9 g of the cationic polymerization composition of the present invention was placed in a polypropylene container having an inner diameter of 1.6 cm and a depth of 1.1 cm, and the cured thick film was 4 mm. . Subsequently, light irradiation was performed for 2 minutes from an irradiation distance of 0.5 cm using a dental light irradiator (TOKUSO POWER LITE, manufactured by Tokuyama Corporation). At this time, the time from the start of irradiation until the tweezer tip was not pierced by the polymer even if the polymer surface was strongly pushed vertically with a sharp tweezer tip was defined as the curing time.

(7) Polymerization shrinkage ratio of composition containing no filler The liquid composition before curing was placed in a 10 ml volumetric flask with a known weight, the liquid level was adjusted to the marked line, and then stored overnight in a 23 ° C. incubator. After storage, the liquid level was confirmed to match the marked line, and the weight was measured. The density of the composition was calculated by subtracting the weight of the volumetric flask before putting the composition from the measured weight and further dividing by the volume. The above operation was performed on three or more samples, and the average value was defined as the composition density d1.

A composition similar to that used for the curing time evaluation was placed in a polypropylene resin container having a diameter of 3 cm and a depth of 1 cm to a depth of 0.5 cm, and irradiated with light for 10 minutes with a dental light irradiator α light (manufactured). And cured. After curing, the mixture was allowed to stand at room temperature for 30 minutes, and the density was measured using a digital hydrometer (manufactured by Sartorius) with the buoyancy-generating liquid as water (water temperature 23-24 ° C.). The same operation was performed on three or more samples, and the average value was taken as the cured body density d2. From the obtained d1 and d2, the following formula (d2-d1) / d2 × 100 = shrinkage rate (%)
Was used to calculate the polymerization shrinkage.

(8) Cured product properties of the composition containing no filler When trying to break the cured product used in the above measurement of the polymerization shrinkage rate by hand, no deformation was observed visually, and no cracks were observed. An unbreakable one was designated as S, and an easily broken one was designated as F.

(9) Curing time of filler-containing composition (paste) A paste was built on a glass plate to a diameter of about 6 mm and a height of 3 mm, and light was irradiated from a distance of about 5 mm on the top surface of the built-up structure. At that time, the hardness of the upper surface and the side surface of the built-up structure was examined so as not to block the irradiation light with a needle having a thickness of about 0.4 mm, and the time when the needle stopped sticking to the entire built-up structure was defined as the curing time.

(10) Polymerization Shrinkage of Filler-Containing Composition An SUS plunger having a diameter of 3 mm and a height of 7 mm is filled with a SUS plunger having a diameter of 3 mm and a height of 4 mm so that the hole height is 3 mm. did. This was filled with a curable composition and pressed from above with a slide glass. The film was faced down and placed on a glass table equipped with a dental irradiator, and a short needle capable of measuring the movement of a minute needle was brought into contact with the SUS plunger. Polymerization and curing were performed with a dental irradiator, and the shrinkage (%) 10 minutes after the start of irradiation was calculated from the movement distance of the short needle in the vertical direction.

(11) Bending strength before immersion in water The curable composition was filled in a 2 × 2 × 25 mm mold, covered with a polypropylene film, and cured by light irradiation with a light irradiator for 1.5 minutes. After storing the cured product in air at 37 ° C. for 7 days, using an autograph (manufactured by Shimadzu Corporation), the distance between the fulcrums is 20 mm, and the crosshead speed is 0.5 mm / min. It measured about hardened | cured material and computed the average value.

(12) Bending strength after immersion in water Similarly, a cured product was prepared, and the cured product was stored in water at 37 ° C. for 7 days. Then, each of the five cured products was measured in the same manner, and the average value was calculated. .

(13) Bending strength retention after immersion in water The value calculated from the following formula was used as the bending strength retention after immersion in water.

(Bending strength retention after immersion in water / bending strength before immersion in water) × 100
= Bending strength retention after immersion in water /%
Example 1
As an essential component of the present invention, (I) oxetane compound is 70 parts by mass of OX-1 and similarly (II) 30 parts by mass of EP-1 as an epoxy compound, and 1 mass of IMDPI as a polymerization initiator. Part, DMAn 0.1 parts by mass, and camphorquinone 0.6 parts by mass were dissolved in a matrix A, and the curing time, cured product properties, polymerization shrinkage, and surface unpolymerization were evaluated. The results are shown in Table 2.

It hardened | cured in 3 second and the hard hardening body was obtained. Further, there was no surface unpolymerization and the polymerization shrinkage was 2.8%.
Examples 2-6
In the same manner as in Example 1, the curing time, cured product properties, polymerization shrinkage rate, and surface unpolymerization were evaluated for the matrices B to F. The results are shown in Table 2.

  All cured within 3 seconds, and a hard cured body was obtained. Further, there was no surface unpolymerization, and the polymerization shrinkage was 2.8% or less.

Comparative Examples 1-3
In the same manner as in Example 1, 70 parts by mass of OX-1 as a polymerizable monomer and 30 parts by weight of EP-3, EP-4, or EP-5 which is an epoxy compound that is not an essential component of the present invention. Using the matrices G, H, and I, the curing time, cured product properties, polymerization shrinkage rate, and surface unpolymerization were evaluated. The results are shown in Table 2.

  All of them required 6 seconds or more for curing, and further exhibited a polymerization shrinkage of 3.5% or more.

Comparative Example 4
As in Example 1, 70 parts by mass of an oxetane compound (OX-3) which is not an essential component of the present invention and a matrix J comprising 30 parts by weight of EP-1 are used as a polymerizable monomer. Properties, polymerization shrinkage, and surface unpolymerization were evaluated. The results are shown in Table 2.

  Although there was no surface unpolymerization, the properties of the obtained cured product were soft and easily deformed.

Comparative Example 5
In the same manner as in Example 1, the matrix K consisting only of OX-1 was used as the polymerizable monomer, and the curing time, cured product properties, polymerization shrinkage rate, and surface unpolymerization were evaluated. The results are shown in Table 2.

  Curing required 10 seconds and the polymerization shrinkage was 3.8%.

Comparative Examples 6 and 7
In the same manner as in Example 1, matrixes L and M consisting of EP-1 alone or EP-2 alone were used as polymerizable monomers, and the respective curing times, cured product properties, polymerization shrinkage rates, and surface unpolymerization were used. Evaluated. The results are shown in Table 2.

  The polymerization shrinkage was as small as less than 1%, but the curing time was long, and the obtained cured product was very brittle.

Comparative Example 8
In the same manner as in Example 1, the matrix N consisting only of EP-3 was used as the polymerizable monomer, and the curing time, cured product properties, polymerization shrinkage rate, and surface unpolymerization were evaluated. The results are shown in Table 2.

  It took 16 seconds to cure and the polymerization shrinkage was 4.1%.

Comparative Example 9
Using a matrix O composed of a radical polymerizable monomer, the curing time, cured product properties, polymerization shrinkage rate, and surface unpolymerization were evaluated. The results are shown in Table 2.

  Polymerization shrinkage was as large as 7.8%, and surface unpolymerization occurred.

Examples 7 and 8
The pastes A and B were evaluated for curing time, polymerization shrinkage, bending strength before and after immersion in water, and bending strength retention. The results are shown in Table 3.

The cured bodies of the prepared pastes A and B exhibit a low polymerization shrinkage ratio of 0.7% or less, and further exhibit high curability and bending strength. Even after immersion in water, 96% or more of the bending strength before immersion is obtained. Maintaining Comparative Examples 10-14
Using each of pastes G, H, I, J, K, L, and M, pastes were prepared according to the above method, and curing time, polymerization shrinkage, bending strength before and after immersion in water, and bending strength retention rate were evaluated for each paste. did. The results are shown in Table 3.

  The cured bodies of pastes G and H using EP-3 and 4 which are not essential components of the present invention had a bending strength after immersion in water decreased to 77% or less before immersion (Comparative Examples 10 and 11). Moreover, the hardening body of the paste I using EP-5 which is not an essential component of the present invention had a polymerization shrinkage ratio as large as 1.1 as compared with the pastes A and B (Comparative Example 12). Similarly, the cured product of paste J using OX-3, which is not an essential component of the present invention, had a remarkably low bending strength (Comparative Example 13). On the other hand, the paste K using only OX-1 among the essential components of the present invention as a monomer required a time of 15 seconds to cure (Comparative Example 14). Similarly, the cured bodies of pastes L and M consisting only of EP-3 or EP-4 had low bending strength (Comparative Examples 15 and 16).

Claims (4)

(I) an oxetane compound having at least two oxetane groups in the molecule,
(II) The carbon atom at the 3-position or 4-position of the cyclohexene oxide group which may have a substituent is represented by the following formula (1):

(Wherein, R ¹ and R ² are a hydrogen atom or a hydrocarbon group which may have a substituent group having a carbon number of 1 to 13, the total number of carbon atoms in R ¹ and R ² is 2 or more .)
An epoxy compound having at least 2 units of a cyclohexene oxide ring-containing unit to which a carbon atom constituting a hydrocarbon ring of a 5-membered ring to 8-membered ring is bonded, or (III) cationic polymerization initiation Dental curable composition comprising an agent. (II) The epoxy compound is represented by the following general formula (a)

(In the formula, R ^{3 to} R ²⁰ are each a hydrogen atom, a halogen atom, an alkoxy group, or an alkyl group, which may be the same or different, and R ²¹ and R ²² are a hydrogen atom or a carbon number of 1 to 10). The total carbon number of R ²¹ and R ²² is 2 or more, and m is an integer of 0 or 1.)
The dental curable composition according to claim 1, which is a compound represented by the formula: (I) The oxetane compound is represented by the following formula (2)

(In the formula, Ar is an aryl group which may have a substituent, and R ²³ is a hydrogen atom or an alkyl group having 1 to 10 carbon atoms.)
The dental cation-curable composition according to claim 1 or 2, which is a compound having at least two groups represented by (I) The compounding ratio of the oxetane compound and the (II) epoxy compound has 1 molecule average a number of oxetane functional groups. (I) The oxetane compound has A mole, and the molecule has an average b number of epoxy functional groups ( II) The cationic cationic curing according to any one of claims 1 to 3, wherein (a × A) :( b × B) is in a range of 90:10 to 45:55, based on B mole of the epoxy compound. Sex composition.