JP4585208B2 - Dental curable composition - Google Patents

Description

  The present invention relates to a dental curable composition. More specifically, the present invention relates to a curable composition that can be suitably used as a denture base lining material.

  Compositions composed of monomers, organic peroxides and tertiary amine compounds that can be polymerized in the presence of radicals such as (meth) acrylic acid esters are rapidly polymerized at room temperature to oral temperature. It has been widely applied as a denture base lining material by utilizing the properties of the cured product.

  Denture base lining material is a material for modifying a denture that has become incompatible with the patient's palate due to long-term use and modifying it so that it can be used again. It is a paste that polymerizes and cures from room temperature to the oral cavity temperature. This is a material that is placed on the denture base, inserted directly into the patient's oral cavity, and adapted to the oral mucosal surface, and then cured and polymerized while being held in the oral cavity for correction. In the lining method, the above combination of compositions is widely used as a material for curing near room temperature. Conventionally, as such a lining material, generally, a powdery component obtained by mixing a powdery synthetic resin such as polymethyl methacrylate, polyethyl methacrylate, a copolymer of methyl methacrylate and ethyl methacrylate, and an organic peroxide; Two-component materials composed of a liquid component obtained by mixing a monomer such as a radical polymerizable compound and a tertiary amine compound are used.

  With such two-component materials, when both components are mixed, the powdered synthetic resin dissolves in the radical polymerizable monomer, thickens into a paste, and can be placed in dentures and shaped in the oral cavity At the same time, by mixing the organic peroxide and the tertiary amine, radicals are easily generated from room temperature to the temperature in the oral cavity, and after a predetermined time has elapsed from the mixing, the function of polymerization hardening proceeds Have

  However, the chemical polymerization initiator (room temperature polymerization initiator) contains a tertiary amine as an essential component, and the tertiary amine remaining in a cured body (hereinafter referred to as a cured backing material) obtained by curing the backing material. In addition, there is a problem that the reaction product of the tertiary amine and the organic peroxide undergoes a chemical change over time, and the cured backing material changes to yellow or brown over time, giving it a dirty impression. There is a need for chemical polymerization initiators that replace organic peroxide-tertiary amine polymerization initiators.

  Various dental chemical polymerization initiators and chemical polymerization curable compositions that do not use tertiary amines have already been proposed. For example, as a system comprising an aryl borate compound as a component thereof, an aryl borate compound and a transition A polymerization initiator system comprising a metal compound (for example, Patent Document 1), an adhesive composition comprising an acidic group-containing polymerizable monomer and an aryl borate compound and a filler (for example, Patent Document 2), an aryl borate compound, Polymerization comprising an acidic compound and an organic peroxide and a polymerization initiator system not containing an amine compound (for example, Patent Document 3), an aryl borate compound, an acidic compound, and a + IV and / or + V vanadium compound There are initiator systems (for example, Patent Document 4).

JP 09-227325 A JP 09-309811 A JP 2002-187907 A JP 2003-096122 A

  However, the chemical polymerization initiator system as described above still has room for improvement in the following points. That is, when a transition metal compound such as vanadium is blended, the transition metal compound itself may be colored, or may be discolored due to an oxidation / reduction reaction over time. Such a coloring problem is hardly a problem when the use site is small, such as when the dental composition is an adhesive or a pretreatment material, but the denture base material and denture base lining material When it is used to obtain a relatively large cured product such as the above, there is room for improvement from the viewpoint of aesthetics.

  In addition, in acidic compounds that dissolve in other compounding components (polymerizable monomer and solvent), such as acidic group-containing polymerizable monomers, the contact area in the oral cavity of denture base materials and denture base lining materials Large materials often cause irritation and sourness and cause discomfort to the wearer.

  When organic peroxides are used, depending on the type, organic peroxides with relatively high activity tend to have a low decomposition temperature, so that a balance between polymerization activity and long-term storage stability is achieved. There is room for improvement in this respect.

  Therefore, there is no discoloration over time so as to cause aesthetic problems, and there is no discomfort to the patient due to irritation, sourness, etc. Furthermore, the curable composition is highly active and excellent in stability. Things were sought.

  As a result of intensive studies to achieve the above object, the present inventors have found that a solid acid that does not dissolve in a radical polymerizable monomer or water as an acid in a polymerization initiator system comprising an aryl borate compound and an acid. By adopting the composition, the composition containing the polymerization initiator was found to be hardly irritating even when it comes into contact with the living tissue in the oral cavity, and further studies were conducted. As the solid acid, the pKa is 2 or less. By adopting those having acidic groups, it was found that sufficient polymerization activity was expressed as a denture base lining material without blending a transition metal compound or an organic peroxide, and the present invention was completed. .

That is, the present invention provides a dental curable composition comprising (A) a radical polymerizable monomer, (B) an aryl borate compound, and (C) a solid acid, wherein the (C) solid acid is a sulfonic acid group. A dental curable composition characterized in that it is a crosslinkable polymer having a particle , or silica-based particles coated or adsorbed with the crosslinkable polymer .

  Even if the dental curable composition of the present invention is inserted into the oral cavity, there is almost no acidity or irritation caused by the acid. Therefore, the patient does not feel uncomfortable due to stimulation or acidity. Further, there is no discoloration of the cured body over time, and aesthetic problems are less likely to occur. Therefore, it is a material that can be particularly suitably used as a direct denture base lining material.

The dental curable composition of the present invention is coated with (A) a radically polymerizable monomer, (B) an aryl borate compound, and (C) a crosslinked polymer having a sulfonic acid group, or the crosslinked polymer. Alternatively, it comprises adsorbed silica-based particles .

  The radical polymerizable monomer used in the present invention is not particularly limited as long as a known radical polymerizable monomer is used as a component of a dental curable composition, in particular, a denture base lining material. .

  As such a radically polymerizable monomer, a (meth) acrylate monomer is mainly used because of its good polymerizability. Specific examples of the (meth) acrylate monomer include the following (1) to (4).

(1) Monofunctional radical polymerizable monomer (meth) acryl such as ethylhexyl (meth) acrylate, isodecyl (meth) acrylate, n-lauryl (meth) acrylate, tridecyl (meth) acrylate, n-stearyl (meth) acrylate Alkyl ester of acid, cyclohexyl (meth) acrylate, benzyl (meth) acrylate, phenoxyethyl (meth) acrylate, isobornyl (meth) acrylate, 2-hydroxyethyl (meth) acrylate, 3-hydroxypropyl (meth) acrylate, tetrahydrofur Furyl (meth) acrylate, glycidyl (meth) acrylate, 1H, 1H, 3H-hexafluorobutyl methacrylate, 1H, 1H, 5H-octafluoropentyl methacrylate, 1H, 1H, 6 Examples include fluorine-containing (meth) acrylates such as H-decafluorohexyl methacrylate and 1H, 1H, 7H-dodecafluoroheptyl methacrylate, and (meth) acrylates represented by the following formulas (a) to (g).

In the above formulas, R ¹ is a hydrogen atom or a methyl group, R ² and R ³ are each an independent alkylene group, R ⁴ is an alkyl group, and m is an integer of 0 or 1-10. And n is an integer of 1 to 10 (provided that m + n is an integer of 2 to 10). The alkylene group as R ² or R ³ is not particularly limited. However, when a synthetic resin powder as described below is used, the above formulas (a) to (e) are considered in consideration of solubility or swelling in the synthetic resin powder. ), The number of carbon atoms is 1 such as methylene group, ethylene group, ethylidene group, trimethylene group, propylene group, tetramethylene group, 1-methyltrimethylene group, 1,2-dimethylethylene group and hexamethylene group. Is an alkylene group having 1 to 6 carbon atoms, and among these, an alkylene group having 1 to 4 carbon atoms is particularly preferable. Moreover, as the alkyl group of R ^{4 in} the compounds represented by the formulas (a) to (g), for the same reason, an alkyl group having 1 to 4 carbon atoms such as a methyl group, an ethyl group, a propyl group, and a butyl group, these Among these, a methyl group or an ethyl group is preferable. For the same reason, the sum of m and n in the formula (f) is preferably 10 or less, more preferably 5 or less, and n in the formula (g) is 10 or less, further 5 or less. preferable.

(2) Bifunctional radical polymerizable monomer Ethylene glycol dimethacrylate, diethylene glycol dimethacrylate, triethylene glycol dimethacrylate, butylene glycol dimethacrylate, neopentyl glycol dimethacrylate, propylene glycol dimethacrylate, 1,3-butanediol dimethacrylate 1,4-butanediol dimethacrylate, 1,6-hexanediol dimethacrylate, 1,9-nonanediol dimethacrylate, 1,10-decanediol dimethacrylate, 2,2-bis (methacryloxyphenyl) propane, 2 , 2-bis [4- (3-methacryloxy) -2-hydroxypropoxyphenyl] propane, 2,2-bis (4-methacryloxyethoxyphenyl) propane, 2,2- Bis (4-methacryloxydiethoxyphenyl) propane, 2,2-bis (4-methacryloxytetraethoxyphenyl) propane, 2,2-bis (4-methacryloxypentaethoxyphenyl) propane, 2,2-bis ( 4-methacryloxydipropoxyphenylpropane, 2- (4-methacryloxyethoxyphenyl) -2- (4-methacryloxydiethoxyphenyl) propane, 2- (4-methacryloxydiethoxyphenyl) -2- (4- Methacryloxytriethoxyphenyl) propane, 2- (4-methacryloxydipropoxyphenyl-2- (4-methacryloxytriethoxyphenyl) propane, 2,2-bis (4-methacryloxypropoxyphenyl) propane, 2,2 -Bis (4-methacryloxyisopropoxyphenyl) Propane, and these acrylate.

(3) Trifunctional radically polymerizable monomer Examples include trimethylolpropane tri (meth) acrylate, trimethylolethane tri (meth) acrylate, pentaerythritol tri (meth) acrylate, and trimethylolmethane tri (meth) acrylate.

(4) Tetrafunctional radically polymerizable monomer Examples include pentaerythritol tetramethacrylate and pentaerythritol tetraacrylate.

  In the present invention, such a radical polymerizable monomer may be used alone, or two or more kinds of radical polymerizable monomers may be used in combination. Further, a plurality of combinations having different numbers of functional groups having radical polymerizability can be freely selected.

  In particular, when the curable composition of the present invention is used as a denture base lining material, it is preferable to use a combination of a monofunctional radical polymerizable monomer and a bifunctional radical polymerizable monomer. , Ethyl methacrylate and the following compounds AE-1 to AE-3

Monofunctional radical polymerizable monomers such as 1,4-butanediol dimethacrylate, 1,6-hexanediol dimethacrylate, 1,9-nonanediol dimethacrylate, 1,10-decanediol dimethacrylate, etc. It is more preferable to select one from each of the functional radical polymerizable monomers and combine them at a mass ratio of 20/80 to 80/20.

  In addition, as the polymerizable monomer used in the dental curable composition, radically polymerizable monomers having an acidic group in the molecule such as phosphinico group, phosphono group, sulfo group and carboxyl group are also widely used. Has been. However, when the dental curable composition of the present invention is a material having a large contact area in the oral cavity, such as a denture base material and a denture base lining material, a radical polymerizable monomer having such an acidic group is used. If added in a large amount, the irritation and sourness become strong, which is not preferable. Therefore, it is preferable that the dental curability of the present invention is made as small as possible even if such a radical polymerizable monomer having an acidic group is blended. Generally, it is preferably 10% by mass or less, more preferably 5% by mass or less, further preferably 3% by mass or less, and substantially contained in all polymerizable monomers. It is particularly preferred that

  The aryl borate compound used in the dental curable composition of the present invention is not particularly limited as long as it is a tetracoordinate boron compound having at least one boron-aryl bond in the molecule, and a known compound can be used. A borate compound having no boron-aryl bond is extremely unstable and is practically impossible to use because it easily decomposes by reacting with oxygen in the air.

  The aryl borate compound used in the present invention is represented by the following general formula (1) from the viewpoint of storage stability and polymerization activity.

(In the above formula, R ⁵ , R ⁶ and R ⁷ are each independently an alkyl group, an aryl group or an alkenyl group, and any of these groups may have a substituent; R ⁸ and R 7 ⁹ is independently a hydrogen atom, a halogen atom, a nitro group, an optionally substituted alkyl group or alkoxy group, or an optionally substituted phenyl group; L ⁺ is a metal cation , A tertiary or quaternary ammonium ion, a quaternary pyridinium ion, a quaternary quinolinium ion, or a quaternary phosphonium ion.).

In the general formula (1), R ⁵ , R ⁶ and R ⁷ each independently represents an alkyl group, an aryl group or an alkenyl group, and these groups may have a substituent.

  The alkyl group is not particularly limited and may be linear or branched, but is preferably an alkyl group having 3 to 30 carbon atoms, more preferably a linear alkyl group having 4 to 20 carbon atoms, Specific examples include an n-butyl group, an n-octyl group, an n-dodecyl group, and an n-hexadecyl group. In addition, as the substituent of the alkyl group, a halogen atom such as a fluorine atom, a chlorine atom or a bromine atom, a hydroxyl group, a nitro group, a cyano group, or a phenyl group, a nitrophenyl group, a chlorophenyl group or the like having 6 to 10 carbon atoms. Examples include C1-C5 alkoxy groups such as aryl groups, methoxy groups, ethoxy groups, and propyl groups, and C2-C5 acyl groups such as acetyl groups. Further, the number and position of the substituents are not particularly limited.

  The aryl group is not particularly limited, and may be a known aryl group, but is preferably a substituted or unsubstituted aryl group in which a single ring or two or three rings are condensed. Examples thereof include groups exemplified as substituents for alkyl groups, and alkyl groups having 1 to 5 carbon atoms such as methyl, ethyl and butyl groups.

  Specifically, the substituted or unsubstituted aryl group is a phenyl group, 1- or 2-naphthyl group, 1-, 2- or 9-anthryl group, 1-, 2-, 3-, 4- or 9-. Phenanthryl group, p-fluorophenyl group, p-chlorophenyl group, (3,5-bistrifluoromethyl) phenyl group, 3,5-bis (1,1,1,3,3,3-hexafluoro-2-methoxy -2-propyl) phenyl group, p-nitrophenyl group, m-nitrophenyl group, p-butylphenyl group, m-butylphenyl group, p-butyloxyphenyl group, m-butyloxyphenyl group, p-octyloxy Examples thereof include a phenyl group and an m-octyloxyphenyl group.

  The alkenyl group is not particularly limited, but is preferably an alkenyl group having 4 to 20 carbon atoms, and examples of the substituent include those exemplified as the substituent of the alkyl group.

In the general formula (1), R ⁸ and R ⁹ may each independently have a hydrogen atom, a halogen atom, a nitro group, an alkyl group or an alkoxy group which may have a substituent, or a substituent. Good phenyl group.

The alkyl group or alkoxy group which may have the substituent is not particularly limited, and may be linear or branched, but is preferably an alkyl group or alkoxy group having 1 to 10 carbon atoms. Yes, and examples of the substituent include those exemplified as the substituent of the alkyl group represented by R ^{5 to} R ⁷ . Specific examples of the alkyl group which may have the substituent include methyl group, ethyl group, n- or i-propyl group, n-, i- or t-butyl group, chloromethyl group, trifluoro group. Examples include a methyl group, a methoxymethyl group, a 1,1,1,3,3,3-hexafluoro-2-methoxy-2-propyl group, and the like, specifically an alkoxy group that may have a substituent. Illustrative examples include methoxy, ethoxy, 1- or 2-propoxy, 1- or 2-butoxy, 1-, 2- or 3-octyloxy, chloromethoxy and the like.

Moreover, the substituent which the phenyl group which may have a substituent also does not specifically limit, Specifically, what was illustrated as a substituent of the aryl group shown by said R < ⁵ > -R < ⁷ > is mentioned.

In the general formula (1), L ⁺ represents a metal cation, a tertiary or quaternary ammonium ion, a quaternary pyridinium ion, a quaternary quinolinium ion, or a quaternary phosphonium ion.

  Examples of the metal cation include alkali metal cations such as sodium ion, lithium ion, and potassium ion, and alkaline earth metal cations such as magnesium ion. Preferred metal cations include tertiary or quaternary ammonium. Examples of ions include tetrabutylammonium ion, tetramethylammonium ion, tetraethylammonium ion, tributylammonium ion, triethanolammonium ion, etc., and quaternary pyridinium ions include methylquinolinium ion, ethylquinolinium ion, and butyl. Examples of quaternary phosphonium ions such as quinolium ions include tetrabutylphosphonium ions and methyltriphenylphosphonium ions.

  Among the aryl borate compounds represented by the above formula (1), an aryl borate compound having three or four boron-aryl bonds is preferable from the viewpoint of stability, and further four from the viewpoint of easy handling, synthesis, and availability. An aryl borate compound having a boron-aryl bond (tetraaryl borate compound) is particularly preferred.

  Specific examples of the borate compound having three boron-aryl bonds in one molecule include monoalkyl triphenyl boron, monoalkyl tris (p-chlorophenyl) boron, monoalkyl tris (p-fluorophenyl) boron, mono Alkyltris (3,5-bistrifluoromethyl) phenylboron, monoalkyltris [3,5-bis (1,1,1,3,3,3-hexafluoro-2-methoxy-2-propyl) phenyl] boron Monoalkyltris (p-nitrophenyl) boron, monoalkyltris (m-nitrophenyl) boron, monoalkyltris (p-butylphenyl) boron, monoalkyltris (m-butylphenyl) boron, monoalkyltris (p -Butyloxyphenyl) boron, monoalkyltris (m Butyloxyphenyl) boron, monoalkyltris (p-octyloxyphenyl) boron, monoalkyltris (m-octyloxyphenyl) boron (wherein alkyl is n-butyl, n-octyl or n-dodecyl in any compound) Sodium salt, lithium salt, potassium salt, magnesium salt, tetrabutylammonium salt, tetramethylammonium salt, tetraethylammonium salt, tributylamine salt, triethanolamine salt, methylpyridinium salt, ethylpyridinium salt Butylpyridinium salt, methylquinolinium salt, ethylquinolinium salt or butylquinolinium salt.

  Examples of the borate compound having four boron-aryl bonds in one molecule include tetraphenyl boron, tetrakis (p-chlorophenyl) boron, tetrakis (p-fluorophenyl) boron, tetrakis (3,5-bistrifluoromethyl). ) Phenyl boron, tetrakis [3,5-bis (1,1,1,3,3,3-hexafluoro-2-methoxy-2-propyl) phenyl] boron, tetrakis (p-nitrophenyl) boron, tetrakis ( m-nitrophenyl) boron, tetrakis (p-butylphenyl) boron, tetrakis (m-butylphenyl) boron, tetrakis (p-butyloxyphenyl) boron, tetrakis (m-butyloxyphenyl) boron, tetrakis (p-octyl) Oxyphenyl) boron, tetrakis (m- Octyloxyphenyl) boron (wherein alkyl represents any of n-butyl, n-octyl or n-dodecyl in any compound), sodium salt, lithium salt, potassium salt, magnesium salt, tetrabutylammonium salt Tetramethylammonium salt, tetraethylammonium salt, tributylamine salt, triethanolamine salt, methylpyridinium salt, ethylpyridinium salt, butylpyridinium salt, methylquinolinium salt, ethylquinolinium salt, butylquinolinium salt, etc. Can be mentioned.

Among these, particularly preferably, in the above formula, R ⁵ , R ⁶ , R ⁷ and

Are aryl borate compounds in which all the groups represented by are the same, that is, the boron atom is substituted with four identical aryl groups.

Further, as L ⁺ , a tertiary or quaternary ammonium ion is preferable, and a tertiary ammonium ion is more preferable.

  These aryl borate compounds can be used alone or in combination.

  The amount ratio of the radical polymerizable monomer and the aryl borate compound in the dental curable composition of the present invention is not particularly limited as long as the ratio is sufficient to cure the radical polymerizable monomer, but the curing rate is not limited. In general, from the viewpoint of physical properties such as mechanical strength of the obtained cured product, the aryl borate compound is generally 0.01 to 20 parts by mass, particularly 0.1 to 10 parts by mass with respect to 100 parts by mass of the radical polymerizable monomer. An amount ratio of mass parts is preferred.

The solid acid in the dental curable composition of the present invention must be a solid acid having an acidic group with a pKa of 2 or less and not soluble in any of water and radical polymerizable monomers. The acidity strength of the solid acid surface correlates with the curability of the dental curable composition of the present invention. The strength of the acidity can be evaluated by a pKa value which means -logKa (Ka: equilibrium constant of proton dissociation), but a solid acid having a pKa greater than 2, for example, a carboxylic acid group having a pKa of about 4 to 5 When a solid acid having an acidic group is used, the curable composition is not cured at all or insufficiently cured, and a cured product having sufficient hardness cannot be obtained. Therefore, it is essential that the pKa of the solid acid has an acid group of 2 or less. It should be noted that even if the acidic group is a compound having a pKa greater than 2 such as a carboxylic acid group as described above, the acid compound is an acidic group-containing polymerizable monomer as described above. When the compound is soluble in the ionic monomer, it is sufficiently cured in about several minutes to several tens of minutes. That is, the pKa of the acidic group is 2 or less, which is necessary only when a solid acid is used for the purpose of reducing irritation and sourness. In the present invention, from the viewpoint of curability and ease of availability, as the solid acid, it is preferable that the pKa value of the acidic group with its is of 1.5 or less, Ru der those having a sulfonic acid group .

  On the other hand, the solid acid may further have another acidic group, that is, an acidic group having a pKa larger than 2 as long as the pKa has an acidic group of 2 or less.

  The pKa value of the solid acid can be measured by a Hammett indicator (dye), and also in the present invention, the pKa of the acidic group possessed by the solid acid is determined using the coloring reaction of the dye. Specifically, when a solid acid to be evaluated is immersed in a toluene solution of 2-amino-5-azotoluene, if the pKa has an acidic group of 2 or less, the solid acid is colored red, and conversely, the pKa is When it has only an acidic group greater than 2, it is colored yellow, so it can be determined whether the pKa of the acidic group of the solid acid is 2 or less or greater than 2.

  Further, the solid acid must not be dissolved in any of the polymerizable monomer (A) and water. When the solid acid is dissolved in water or a radical polymerizable monomer, it tends to feel sour when the dental curable composition is inserted into the oral cavity. The cause is not necessarily clear, but when a solid acid that dissolves in water is selected, when the dental curable composition is inserted into the oral cavity, the solid acid dissolves into saliva and spreads sourness in the mouth. It is estimated that. Further, when the solid acid is dissolved in the radical polymerizable monomer, the curable composition and the taste receptor organ of the tongue are compared with the case where the solid acid is present in the dental curable composition in the form of particles. It is presumed that the contact ratio increases and it becomes easier to feel the taste.

The solid acid to be blended in the dental curable composition of the present invention, cross-linking polymer (powder) having a scan sulfonic acid group or, or coated with such a crosslinked polymeric, or or adsorbed And silica-based particles. In addition, since many non-crosslinked polymers having an acidic group are dissolved in water, it is generally not equivalent to the solid acid in the present invention.

  Examples of the cross-linked polymer having an acidic group having a pKa of 2 or less include an acidic group having a pKa of 2 or less, such as styrenesulfonic acid, vinylsulfonic acid, 2- (meth) acrylamido-2-methylpropanesulfonic acid, etc. A cross-linked polymer obtained by copolymerizing a polymerizable monomer and a polyfunctional polymerizable monomer such as divinylbenzene, divinylsulfone, or N, N-methylenebisacrylamide is preferable.

  As the solid acid in the present invention, a powder obtained by pulverizing a crosslinked polymer having an acidic group having a pKa of 2 or less as described above into a desired size or shape (hereinafter also referred to as acidic polymer powder) may be used. However, those coated with silica particles with such a polymer or those adsorbed on silica particles are more preferred (hereinafter also referred to as acidic polymer-coated powder).

  Such an acidic polymer-coated powder is usually presumed to be due to the localized acidic groups on the surface, but tends to be excellent in curability as compared with the case where an acidic polymer powder is used. From this, when the acid equivalent contained in a solid acid is the same, there exists an advantage that an addition amount can be reduced compared with acidic polymer powder. Furthermore, when an acidic polymer-coated powder is produced by a method as described later, an acidic polymer-coated powder according to the particle size and particle size distribution of the silica-based particles used as a raw material can be produced. Its particle size and particle size distribution are easier to control than molecular powder.

  In the present invention, it is preferable to use a solid acid as described above. More preferably, it is a powder with a particle size of 0.01-100 micrometers, More preferably, it is a powder with 0.01-50 micrometers. The smaller the particle size, the less the roughness when mixed with the polymerizable monomer (A), and the better the curability. Needless to say, powder is a property in the state of the solid acid alone. For example, when mixed with a polymerizable monomer, it usually becomes a slurry or a paste.

  The method for obtaining the solid acid as described above is not particularly limited, but can be preferably produced by the following method. That is, in the case of acidic polymer powder, a general cross-linked strong acidic ion exchange resin may be pulverized to a required size. When the obtained ion exchange resin is in a salt form, it may be converted into an acid form with hydrochloric acid before or after pulverization. As such a strongly acidic ion exchange resin, there is typically a styrene sulfonic acid / divinylbenzene copolymer. As an industrial material, a particle having a diameter of about 300 μm to about 2 mm or a film having a thickness of about 0.1 mm to 1 mm. It is available in the form. Of course, there is no problem even if it is synthesized by a known method, and other than the styrene sulfonic acid / divinylbenzene copolymer may be used. The pulverization method is not particularly limited as long as it is a commonly used pulverization method, but there are mechanical pulverization methods such as a lump lump machine, ball mill, vibration ball mill, pulpelizer, ACM pulperizer, roller mill, Victory mill, feather mill jet mill, etc. Preferably used. The pulverization is roughly classified into a wet pulverization method using water or an organic solvent and a dry pulverization method not using them, and any of these methods can be suitably used. When wet pulverization is performed, the dispersion medium may be appropriately removed and then used in the dental curable composition of the present invention.

  A method for producing silica-based particles coated with a cross-linked polymer having an acidic group having a pKa of 2 or less, or silica-based particles adsorbing such a cross-linked polymer is not particularly limited. Since the particle size and particle size distribution of the system particles are hardly changed, solid acid powders with various particle sizes and particle size distributions can be obtained, and the thickness and acid equivalent of the coating layer can be easily controlled. What was manufactured with the following method is suitable.

  That is, the surface of silica-based particles is treated with a cyclic siloxane, a polymerizable monomer is adsorbed on the treated silica-based particles, and the polymerizable monomer is polymerized, and then the polymer has an acidic group having a pKa of 2 or less. It is a method to introduce. This method can be efficiently carried out dry (without using a solvent), and therefore the particles hardly aggregate as in the case of using a solvent.

  The silica-based particles are not particularly limited, and may be appropriately selected according to a desired material, shape, or the like when blended as a solid acid in the curable composition of the present invention. For example, silicas such as quartz, precipitated silica, fumed silica, sol-gel silica; composite oxides such as silica-alumina, silica-titania, silica-zirconia; silicates such as calcium silicate and talc; silica such as System particles. Among these, silicas are particularly preferable because they are chemically stable, have no toxicity, have excellent coating uniformity, and can easily obtain various particles having different particle size distributions, shapes, and the like.

  The average particle size and particle size distribution of such silica-based particles may be appropriately selected as necessary, and are not particularly limited. As described above, the solid acid has a particle size of 100 μm or less. It is preferable that the silica-based particles used have an average primary particle size of preferably 0.005 to 50 μm, and more preferably 0.005 to 10 μm. The shape is not particularly limited, and may be spherical, irregular, or irregular.

  The method for treating such silica-based particles with cyclic siloxane is not particularly limited, and may be performed according to a known method. Specific examples of the cyclic siloxane used include octamethylcyclotetrasiloxane, hexamethylcyclotrisiloxane, tetramethyltetraphenylcyclotetrasiloxane, trimethyltriphenylcyclotrisiloxane, tetramethyltetravinylcyclotrisiloxane, and trimethyltrisiloxane. Examples thereof include cyclic siloxanes such as vinylcyclotrisiloxane, tetramethylcyclotetrasiloxane, and trimethylcyclotrisiloxane.

  Specifically, the method of treating with such a cyclic siloxane is described below. While stirring silica-based particles with a high-speed stirring device such as a Henschel mixer in an inert gas atmosphere such as nitrogen or argon, the cyclic siloxane is gaseous. Alternatively, it can be produced by adding it in liquid form and heating it to a predetermined temperature in a sealed reaction system. The method of adding the cyclic siloxane to the silica-based particles may be either liquid or gaseous, and when added in liquid form, it may be added dropwise or by spraying. It is particularly preferable to add it in the form of a gas from the viewpoint that it can be uniformly processed. The amount of cyclic siloxane to be used cannot be generally specified depending on the particle size, specific surface area, pore volume, and the like of the silica-based particles, but is generally about 10 to 80 g with respect to 100 g of the silica-based particles. The heating temperature is not particularly limited as long as the surface of the silica-based particles can be hydrophobized by cyclic siloxane, but in general, the heating temperature is preferably equal to or higher than the boiling point of the cyclic siloxane used, and is usually 100 to 300. It is about ℃. Further, the stirring speed at the time of stirring is not particularly limited, and cannot be generally specified depending on the stirring device used, but is generally about 200 to 3000 rpm.

  By adopting such a dry treatment, it is possible to prevent agglomeration of silica-based particles, and if necessary, coating with the vinyl-based polymer described below in the same reaction vessel is also possible. It is advantageous. Of course, a known wet process may be employed as necessary.

  As a method of adsorbing the polymerizable monomer to the thus obtained cyclic siloxane-treated silica-based particles, a method in which the polymerizable monomer is sprayed onto the cyclic siloxane-treated silica-based particles while stirring the cyclic siloxane-treated particles is particularly preferable. Is preferred. As the polymerizable monomer, an acidic group having a pKa of 2 or less can be introduced into a polymer obtained by polymerization, and after introducing the acidic group, the component (A) in the present invention is also used. Any polymer that is insoluble in water can be used. Specifically, a polymerizable monomer capable of introducing a sulfonic acid group such as styrene, α-methylstyrene, vinyl naphthalene, divinylbenzene, divinylsulfone, ethylene glycol di (meth) acrylate, diethylene glycol (meth) acrylate, A mixture with a polyfunctional polymerizable monomer such as hexamethylene di (meth) acrylate, nonamethylene di (meth) acrylate or trimethylolpropane tri (meth) acrylate is preferred. By blending such a polyfunctional polymerizable monomer, the resulting polymer becomes a cross-linked type, and therefore it is very easy to make it insoluble in the component (A) and water. The blending ratio of the polyfunctional polymerizable monomer is not particularly limited, but is generally about 0.1 to 10% by mass in the total polymerizable monomer used for coating the silica-based particles.

The amount of the polymerizable monomer used in this production method is not particularly limited, and may be appropriately set depending on a desired coating thickness. The greater the amount used, the greater the coating amount (thickness of the coating), but if it is too large, it becomes a bulky polymer, and the silica particles are scattered in the polymer. Although it depends on the particle diameter of the silica-based particles used, it is common to use 2 × 10 ⁻⁵ to 2 × 10 ⁻¹ g of monomer per 1 m ² of specific surface area of the silica-based particles used as a raw material. .

  Moreover, it is preferable to dissolve a thermal polymerization initiator in the polymerizable monomer used for coating the silica-based particles in that the polymerization after being adsorbed on the silica-based particles becomes easy. Specific examples of the thermal polymerization initiator include octanoyl peroxide, lauroyl peroxide, t-butylperoxy-2-ethylhexanoate, benzoyl peroxide, t-butylperoxyisobutyrate, and t-butylperoxide. Organic peroxides such as oxylaurate, t-hexylperoxybenzoate, di-t-butyl peroxide, 2,2-azobisisobutyronitrile, 2,2-azobis- (2,4-dimer) Azobis-based polymerization initiators such as valeronitrile). These polymerization initiators are generally used in an amount of 0.1 to 20 parts by weight, preferably 0.5 to 10 parts by weight, based on 100 parts by weight of the polymerizable monomer used for coating the silica-based particles. is there.

  By stirring the cyclic siloxane-treated silica-based particles and spraying the polymerizable monomer (and polymerization initiator) onto the silica-based particles, a substantially uniform polymerizable monomer coating is formed on the silica-based particles. Formed on top. The spraying speed is preferably 1 to 20 ml / min per 100 g of silica-based particles. The temperature condition is not particularly limited and may be under cooling or under heating. However, since the polymerizable monomer is polymerized before coating at an excessively high temperature, generally about −10 to 40 ° C. is preferable. Further, the stirring speed at the time of stirring is not particularly limited, and cannot be generally specified depending on the stirring device used, but is generally about 200 to 3000 rpm.

  After adding a predetermined amount of the polymerizable monomer, the polymerizable monomer is polymerized. The method of polymerizing is not particularly limited, but if a thermal polymerization initiator is mixed in the polymerizable monomer as described above, it is easily polymerized by heating. The heating temperature is not particularly limited as long as the polymerization reaction occurs, and may be appropriately set depending on the decomposition temperature of the used polymerization initiator, but is generally 40 to 230 ° C., preferably 50 to 180. It is about ℃. The polymerization time may be appropriately set according to the activity of the polymerization initiator, and is generally 30 to 180 minutes.

Subsequently, an acidic group having a pKa of 2 or less is introduced into the polymer of the polymer-coated silica particles thus obtained. Acidic groups are pKa of that always 2 or less, it is also easy scan sulfonic acid group-introduced. A method for introducing a sulfonic acid group may be a known method depending on the type (chemical structure) of the polymer. For example, when a polymerizable monomer having an aromatic ring such as styrene is used, sulfuric acid is used. It is easily sulfonated by contact with fuming sulfuric acid, sulfur trioxide, chlorosulfonic acid and the like. In order to prevent the particles from aggregating, the sulfonation is also preferably performed by a dry method. Specifically, a method of contacting the polymer-coated silica-based particles with a sulfur trioxide gas while stirring is particularly preferable.

  The amount of acidic groups contained in the acidic polymer-coated silica-based particles obtained by such a production method can be easily controlled by the coating thickness of the polymer and the action amount of the sulfonating agent.

  As a solid acid in this invention, it is preferable to use that whose acid amount is 0.005-4 meq / g-solid acid, More preferably, it is 0.1-3 meq / g-solid acid.

  The amount of the solid acid used in the dental curable composition of the present invention is not particularly limited, but is 0.05 to 200 mass with respect to the radical polymerizable monomer constituting the dental curable composition. Parts, preferably 0.1-100 parts by mass. Generally, the larger the amount of acidic groups having a pKa of 2 or less, the smaller the amount of solid acid to be blended.

  As described above, the dental curable composition of the present invention has excellent properties such as less irritation and discoloration. Such properties are useful in various dental curable compositions, but are particularly suitable as denture base lining materials.

  When the dental curable composition of the present invention is used as a denture base lining material, it is known as a component of a denture base lining material in addition to the polymerizable monomer, aryl borate compound and solid acid described above. It is preferable to blend other components. Examples of such components include synthetic resin powders; inorganic fillers; alcohols or plasticizers such as ethanol, dibutyl phthalate and dioctyl phthalate; polymerization inhibitors such as butylhydroxytoluene and methoxyhydroquinone; dyes, pigments and fragrances.

  For example, as the synthetic resin powder, a powdery synthetic resin such as polymethyl methacrylate, polyethyl methacrylate, or a copolymer of methyl methacrylate and ethyl methacrylate can be suitably used.

  In the dental curable composition of the present invention, when all the components are mixed, the aryl borate compound is decomposed by the action of the solid acid to generate radicals, and the polymerizable monomer starts to polymerize by the action of the radicals. And harden. Therefore, the components are usually packaged and stored in several portions so that polymerization does not start, and they are generally mixed at the time of use. The separation and storage form at this time is not particularly limited as long as polymerization does not start, but when used as a denture base lining material containing synthetic resin powder, each component is easily measured and handled easily. From this point of view, it is divided into a powder material mainly composed of synthetic resin powder and a liquid material mainly composed of a polymerizable monomer, and an aryl borate compound is specified in one of them and a solid acid is specified in the other. What is necessary is just to mix | blend in the ratio.

  Also, in order to obtain a two-paste denture base lining material, a paste composed of a radically polymerizable monomer, a solid acid and a filler and a paste composed of a radically polymerizable monomer, an aryl borate compound and a filler are separated from each other. A method in which the container is stored in a container and used as a kit is also suitable.

  In the case of such a kit, a predetermined amount of powder and liquid combination or two kinds of pastes are taken out from each container and mixed at the time of use, mixed and placed in a predetermined mold or arranged in shape. It can be cured at room temperature or in the oral cavity.

  Further, the dental curable composition of the present invention is not limited to the direct denture base lining material as described above, but is used as an indirect method material for performing the lining operation on a gypsum model outside the oral cavity. Further, the dental curable composition may be applied to a dental adhesive, a pretreatment material, a restoration material, and the like.

  EXAMPLES The present invention will be specifically described below with reference to examples, but the present invention is not limited to these examples. In addition, the compounds other than the solid acid used in Examples and Comparative Examples and their abbreviations are shown in (1), and the evaluation method of the composition or composition cured product is shown in (2) to (5). The method is shown in (6).

(1) Abbreviation
[Borate compounds]
PhBNa; tetraphenyl boron sodium salt PhBTEOA; tetraphenyl boron triethanolamine salt
[Radically polymerizable monomer]
AE-1; acetoacetoxyethyl methacrylate HPr; propionoxyethyl methacrylate HD; hexamethylenediol dimethacrylate ND; nonamethylenediol dimethacrylate PM; 2-methacryloyloxyethyl dihydrogen phosphate and bis (2-methacryloyloxy) Ethyl) hydrogen phosphate mixture (molar ratio 1: 4)
MMPS; 2-methacrylamide-2-methylpropanesulfonic acid
[Other ingredients]
EMA-1; polyethyl methacrylate (manufactured by Sekisui Plastics Co., Ltd .: EMA-35)
MMA-1; cross-linked polymethyl methacrylate (manufactured by Sekisui Plastics Co., Ltd .: MB30X-5)
(2) Evaluation of taste of denture base lining material paste 2g of paste mixed with powder or mixed with 2 pastes was inserted into the oral cavity to evaluate the taste. The test was conducted with five subjects, scored according to the evaluation criteria shown below, and evaluated by the average value.
Score 3 Extremely strong score 2 Strong score 1 Slightly taste score 0 Feel no taste (3) Evaluation of curability The curability of the composition is 20 × the paste after mixing powder or 2 pastes. Poured into a 20 × 2 mm mold and cured at 37 ° C. for 1 hour. Among the cured bodies, a sample cured to such a hardness that the hardness could be measured was measured for Knoop hardness under a condition of applying a load of 100 g for 20 seconds with a micro hardness meter manufactured by Matsuzawa Seiki. Samples that did not cure to such an extent that the hardness could be measured or those that did not cure at all were marked with x.

(4) Discoloration test The obtained cured product was stored in 80 ° C. water for 30 days, and the degree of discoloration of the cured product before and after storage was evaluated according to the evaluation criteria shown below.
Score 4 Brown color change score 3 Yellow color change score 2 Slight yellow color change score 1 White turbidity only score 0 No change (5) pKa evaluation method of solid acid The pKa evaluation of solid acid was performed by coloration of Hammett reagent. Hammett's reagent is a group of organic dyes. When a solid acid is added to each reagent solution, color is developed according to the pKa value of the solid acid. Since the pKa value at which each Hammett reagent changes color is already known, the range of the pKa value of the solid acid can be known by putting a solid acid into each reagent solution and observing the color development.

  Here, the evaluation was performed using a toluene solution (0.2 wt%) of eight kinds of Hammett reagents that change color at pKa 0.8 to 4.8. Eight types of dispersions in which 0.1 g of solid acid to be evaluated was dispersed in 5 ml of toluene were prepared in advance. Then, each of the above Hammett reagents was dropped with a dropper, and after waiting for the solid acid to settle, the color of the solid part was examined. The Hammett reagents used were methyl red (MR, pKa 4.8; Wako Pure Chemical), bromophenol blue (BPB, pKa 4.1; Wako Pure Chemical), benzene-1-naphthylamine (BNA, pKa 4.0; Wako Pure Chemical). ), P-dimethylaminoazobenzene (MMAB, pKa3.3; Wako Pure Chemical Industries), 2-amino-5-azotoluene (AAT, pKa 2.0; Wako Pure Chemical Industries), thymol blue (TB, pKa1.7; Wako Pure Chemical Industries, Ltd.) ), Benzeneazodiphenylamine (BAP, pKa1.5; Wako Pure Chemical), crystal violet (CV, pKa0.8; Wako Pure Chemical).

(6) Production method of solid acid Production Example 1 (SA-1)
A strongly acidic cation exchange resin (Mitsubishi Chemical Co., Ltd .: Diaion PK228) was packed in a column and washed with 1 mol / liter hydrochloric acid aqueous solution to remove metal ions contained in the resin. Subsequently, excess hydrochloric acid was removed by washing with distilled water. The washed resin was dried to a constant weight at 60 ° C. under reduced pressure and used for pulverization. The resin was first pulverized in a magnetic mortar, and then further pulverized using an agate mortar until the average particle size of the powder obtained by pulverization became 10 μm (hereinafter, this powder was SA-1). When the pKa of this powder was evaluated, the pKa was less than 0.8. Table 1 shows the color tone of each Hammett reagent. The acid equivalent of this solid acid SA-1 was 4.3 meq / g.

Production Example 2 (SA-2)
50 g of silica powder (product name, QS102, specific surface area 200 m 2 / g, average secondary particle diameter 2 μm, average primary particle diameter 16 nm, manufactured by Tokuyama) was charged into a stainless steel autoclave having an internal volume of 1000 ml. After the inside of the autoclave was replaced with nitrogen gas, 20 g of cyclic siloxane (octamethylcyclotetrasiloxane: hereinafter referred to as D4) was atomized with a two-fluid nozzle while rotating the stirring blade attached to the autoclave at 400 rpm. Sprayed uniformly. After stirring for 30 minutes with nitrogen gas flowing, the autoclave was sealed and heated at 275 ° C. for 1 hour. Subsequently, the system was decompressed while being heated to remove unreacted cyclic siloxane.

  50 g of silica powder surface-treated with the above cyclic siloxane (having a specific surface area of 160 m <2> / g) was charged into a stainless steel autoclave having an internal volume of 1000 ml. After the interior of the autoclave was replaced with nitrogen gas in advance, the stirring blade attached to the autoclave was rotated at 400 rpm, and a mixed solution of 5 g of styrene, 0.6 g of divinylbenzene, and 0.3 g of t-butylperoxy-2-ethylhexanoate. Was atomized with a two-fluid nozzle and sprayed uniformly onto the silica powder to wet the surface. After stirring for 30 minutes while flowing nitrogen gas, the autoclave cock is closed and sealed, the temperature is raised from 20 ° C. to 80 ° C., and maintained at the same temperature for 1 hour to form a crosslinkable vinyl polymer coating layer. Formed.

  The obtained coated silica is transferred to a polytetrafluoroethylene container, liquid sulfur trioxide is put into a flask directly connected to the container, and vaporized sulfur trioxide is fed into the container containing silica with nitrogen gas. The sulfur oxide gas concentration was set to 30 vol% or more, and the mixture was heated to 80 ° C. for 1 hour with stirring in a sealed state for sulfonation.

Subsequently, the system was depressurized to completely remove unreacted sulfur trioxide gas in silica, and silica powder was recovered (hereinafter, this powder is SA-2). The average primary particle diameter of the obtained styrene sulfonic acid polymer-coated silica powder was 0.021 μm, specific surface area 130 m ² / g, and acid equivalent 0.8 meq / g. Moreover, when pKa was evaluated, it was 0.8 or less.

Production Example 3 (SA-3)
A powder (SA-3) was obtained in the same manner as in Production Example 2, except that a weakly acidic cation exchange resin (manufactured by Mitsubishi Chemical Corporation: Diaion WK20) was used instead of the strongly acidic cation exchange resin. When the pKa of this powder was evaluated, it was in the range of 3.3 to 4.0. The acid equivalent of the solid acid SA-3 was 8.7 meq / g.

Production Example 4 (SA-4)
A powder (SA-4) was obtained in the same manner as in Production Example 2, except that a chelate ion exchange resin (manufactured by Mitsubishi Chemical Corporation: Diaion CR11) was used instead of the strongly acidic cation exchange resin. When the pKa of this powder was evaluated, it was in the range of 3.3 to 4.0. The acid equivalent of the solid acid SA-4 was 3.4 meq / g.

Production Example 5 (SA-5)
50 g of silica powder surface-treated with cyclic siloxane by the same method as in Production Example 1 was charged into a stainless steel autoclave having an internal volume of 1000 ml. After the inside of the autoclave was replaced internally with nitrogen gas in advance, the stirring blade attached to the autoclave was rotated at 400 rpm, 5 g of methacrylic acid, 0.6 g of divinylbenzene, and 0.3 g of t-butylperoxy-2-ethylhexanoate. The mixed solution was atomized with a two-fluid nozzle and sprayed uniformly onto the silica powder to wet the surface. After stirring for 30 minutes while flowing nitrogen gas, the autoclave cock is closed and sealed, the temperature is raised from 20 ° C. to 80 ° C., and maintained at the same temperature for 1 hour to form a crosslinkable vinyl polymer coating layer. Formed.

The average primary particle diameter of the obtained methacrylic acid polymer-coated silica powder (hereinafter, SA-5) was 0.023 μm, specific surface area 130 m ² / g, and acid equivalent 0.8 meq / g. Moreover, when pKa of this powder was evaluated, it was in the range of 3.3-4.0.

  Further, synthetic spherical silica “Excelica SE-1” manufactured by Tokuyama Corporation was used as it was. Hereinafter, it is abbreviated as SA-6. Moreover, when pKa of this powder was evaluated, it was in the range of 4.1-4.8.

  Note that none of the above SA-1 to SA-6 was dissolved in water and any of the polymerizable monomers used in Examples or Comparative Examples.

Examples 1-5, Comparative Examples 1-6
A liquid material composed of a polymerizable monomer and an aryl borate compound with a composition shown in Table 2 and a powder material composed of polyethyl methacrylate and a solid acid were prepared, and the ratio of the powder material to the liquid material was 2: 1 by mass ratio. The paste mixed so that the taste, curability, and discoloration of the cured product were evaluated. The evaluation results are shown in Table 5.

Example 6 and Comparative Examples 7 and 8
A liquid material composed of a polymerizable monomer and a solid acid and a powder material composed of polyethyl methacrylate and an aryl borate compound with the composition shown in Table 3 were prepared, and the ratio of the powder material to the liquid material was 2: 1 by mass ratio. Table 5 shows the results of the same evaluation as in Example 1 for the paste thus mixed. PM used in Comparative Example 7 was completely dissolved in other polymerizable monomers. The MMPS used in Comparative Example 8 is an acid compound that dissolves very easily in water.

Examples 7 and 8
A paste 1 composed of a radically polymerizable monomer, an aryl borate compound and a filler and a paste 2 composed of a radically polymerizable monomer, a solid acid and a filler having the composition shown in Table 4 were prepared. The paste obtained by mixing both pastes at a volume ratio of 1: 1 was evaluated in the same manner as in Example 1, and the results are shown in Table 5.

Comparative Example 9
A liquid material obtained by dissolving 1 part by mass of diethanol-p-toluidine (manufactured by Tokyo Chemical Industry Co., Ltd.) in a radical polymerizable monomer composed of 60 parts by mass of AE-1 and 40 parts by mass of ND, and 100 parts by mass of EMA-1. The same evaluation as in Example 1 was performed on a paste in which 1 part by mass of benzoyl peroxide (manufactured by Kawaguchi Pharmaceutical Co., Ltd.) was mixed at a mass ratio of 1: 2. The results are shown in Table 5.

Claims (3)

A dental curable composition comprising (A) a radical polymerizable monomer, (B) an aryl borate compound, and (C) a solid acid, wherein the (C) solid acid is a cross-linked polymer having a sulfonic acid group A dental curable composition comprising silica particles coated or adsorbed with molecules or the cross-linked polymer The dental curable composition according to claim 1, wherein (C) the solid acid is silica-based particles coated with a cross-linked polymer having a sulfonic acid group . A denture base lining material comprising the dental curable composition according to claim 1 or 2.