JP2010018565A - Curable material for dental use - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a curable material for dental use which has high impact resistance and coloring resistance and which is excellent in operationality. <P>SOLUTION: The curable material for dental use includes: (A) a core shell type particle which has a core portion consisting of a crosslinked silicone and a shell portion consisting of a (meth)acrylate based polymer forming a surface layer and which preferably has an average particle size of 10-500 nm and thickness of the shell portion of 5-40 nm, (B) a (meth)acrylate based monomer and (C) a polymerization initiator, and preferably further includes (D) a filler other than the (A) core shell type particles. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a dental curable material, and more specifically, a denture base comprising a core part made of silicone and core / shell type particles having a shell part made of a (meth) acrylic acid polymer forming a surface layer. The present invention relates to a dental curable material suitable for use.

  In dental treatment, curable materials mainly composed of (meth) acrylic acid monomers represented by composite resins, denture bases, denture base lining materials, orthodontic materials, artificial teeth, dental normal temperature polymerization resins, etc. Widely used. However, it is known that (meth) acrylic acid polymers have low mechanical strength such as impact resistance.

  Examples of methods for improving impact resistance include elastomer particles such as urethane rubber, polybutadiene rubber, butyl rubber, nitrile rubber, natural rubber, colorobrene rubber, and fluorine rubber; graft polymer particles of diene rubber and hard resin; olefin rubber Methyl methacrylate polymer particles containing a core / shell type particle comprising at least one hard layer and at least one soft layer and having an outermost hard layer, etc., is blended in the (meth) acrylic acid polymer. Methods have been proposed (see Patent Documents 1 to 4). However, many of these cannot be satisfied with the effect of improving the impact resistance, and dental materials containing these soft resin particles have a problem that they are easily discolored by long-term use in the oral cavity. This is because the soft resin particles blended to improve the impact resistance are easily dyed by coloring components of foods and beverages. In dental materials where aesthetics are commercial value, the commercial value is greatly reduced. I was letting.

  On the other hand, since silicone rubber particles have good properties such as elasticity, water resistance, thermal stability and transparency, they are widely used industrially as impact resistance modifiers. The silicone rubber particles are excellent in coloring resistance and tasteless and odorless. Therefore, when the silicone rubber particles are blended with the dental material, improvement of the problem of deterioration in aesthetics due to coloring can be strongly expected. However, silicone rubber particles have extremely low compatibility with organic materials, and therefore, even when blended with a curable material containing the (meth) acrylic acid monomer as a main component, it is difficult to uniformly disperse. It was not effective.

  In addition, core-shell type particles composed of a core portion made of silicone and a shell layer made of a (meth) acrylic acid-based polymer covering the core portion have also been proposed as an impact modifier for organic materials ( For example, see Non-Patent Document 1.) However, nothing is described about using an organic material containing the core-shell type particles as a dental material, and if this material is used in the dental material, the impact resistance can be improved. Although it can be expected to be effective to some extent, other properties were unknown. In particular, in the core-shell type particles whose surface is composed of a methacrylic acid polymer, nothing has been studied about the colorability of the particles, and the dental use has the problem of severe discoloration due to the speciality used in the oral cavity. No attempt has been made to use the particles in the hope of improving this problem for materials.

JP-A-1-275509 Japanese Laid-Open Patent Publication No. 3-63205 JP-A-6-57157 Japanese Laid-Open Patent Publication No. 11-310508 Published by Hideo Nishio, “Weekly Nanotech” No. 1291, Sangyo Times, Inc., March 5, 2007, p. 9

  In the above background, the present invention is excellent in impact resistance and operability, and further, due to long-term use in the oral cavity, it is difficult to discolor even when exposed to coloring components of foods and beverages for a long time. It is an object to develop an excellent dental curable composition.

  As a result of intensive studies to solve the above-mentioned problems, the inventors of the present invention have a dental curable material containing a (meth) acrylic acid monomer and a polymerization initiator, a core portion made of the silicone, and a surface layer. It has been found that the above-mentioned problems can be solved by blending core-shell type particles having a shell portion made of a (meth) acrylic acid-based polymer that forms the present invention, and the present invention has been completed.

That is, the present invention provides (A) a core part made of silicone and a core-shell type particle (B) (meth) acrylic acid monomer having a shell part made of a (meth) acrylic acid polymer forming a surface layer, and (C) A dental curable material comprising a polymerization initiator.

  The dental curable composition in the present invention contains core-shell type particles having a core part made of silicone and a shell part made of a (meth) acrylic acid polymer forming a surface layer. Since the surfaces of the particles are coated with a shell portion made of a (meth) acrylic acid polymer, the particles have excellent compatibility with the (meth) acrylic acid monomer and can be uniformly dispersed. And since the core part which consists of silicone is soft and rich in elasticity, the outstanding impact resistance improvement effect can be provided with respect to the hardening body of the said curable composition.

  Furthermore, since the shell portion made of a (meth) acrylic acid-based polymer that is easily colored is held only on the surface layer, and the silicone that forms the core portion is difficult to be colored, the coloring component of foods and beverages as a dental material Even when used in the oral cavity exposed to the above, the coloring component does not penetrate into the inside, is excellent in coloration resistance, and can exert a remarkable effect in this application.

  The dental curable composition of the present invention contains, as component (A), core / shell type particles having a core portion made of silicone and a shell portion made of a (meth) acrylic acid polymer forming a surface layer. Let As a result, a dental curable composition having excellent impact resistance and operability, and also excellent in coloration resistance can be obtained. When the core part made of silicone comes out on the surface layer, the dispersibility and operability of the particles are lowered, so the shell part made of a (meth) acrylic acid-based polymer substantially completely covers the particle surface. It is necessary to cover 95% or more, more preferably 98% or more of the particle surface.

  The shell part made of the (meth) acrylic acid-based polymer only needs to cover the surface layer of the core part made of the crosslinked silicone, but the shell is not peeled off from the core part when dispersed in the curable composition. The core portion and the shell portion are preferably chemically bonded.

In this core-shell type particle, the silicone forming the core portion is a crosslinked polymer having a three-dimensional structure having a Si—O—Si bond as a skeleton. Such silicones are not particularly limited and known ones can be applied. Usually, diorganosiloxane units (R ₂ SiO ₂ ) are the main units, and monoorganosiloxane units (RSiO ₃ ) or siloxanes are used. by units (SiO ₄₎ is interwoven, or the like is applied which is crosslinked. Further, a triorganosiloxane unit (R ₃ SiO) may be contained. These are generally introduced using the corresponding organochlorosilanes, organopolysiloxanes, alkoxysilanes, cyclic siloxanes, etc., from which the above siloxane units are obtained.

  In each of the above organosiloxane units, R represents an organic group. The organic group is not particularly limited, and is preferably an alkyl group having 1 to 8 carbon atoms such as a methyl group, an ethyl group, a propyl group, a butyl group, or an octyl group; An aryl group; a hydrocarbon group such as a cycloalkyl group having 3 to 8 carbon atoms such as a cyclopropyl group and a cyclohexyl group is preferable. Moreover, these hydrocarbon groups may have a substituent such as a halogen atom, and for example, a substituted alkyl group such as a chloromethyl group and a 3,3,3-trifluoropropyl group can be preferably used. Furthermore, the organic group of R is a hydrocarbon group having a polymerizable group such as a vinyl group, a propyl group, an allyl group, or a styryl group in order to function as a functional group for chemically bonding the core part and the shell part. Alternatively, it may be a substituted hydrocarbon group into which a polymerizable substituent such as a (meth) acryloxy group is introduced. Of these organic groups represented by R, a methyl group is particularly preferred because of its ease of synthesis.

  Since these silicones are less likely to exhibit an impact resistance effect at a temperature below the softening point, the softening point is preferably 20 ° C. or lower, more preferably −10 to −150 ° C.

  On the other hand, the (meth) acrylic acid polymer forms the shell portion. Here, the (meth) acrylic acid-based polymer is a general term for polymers obtained by polymerizing a polymerizable simple substance derived from the monomer in addition to acrylic acid and methacrylic acid. As such a (meth) acrylic acid polymer, a polymer obtained by polymerizing a (meth) acrylic acid monomer or the like of the component (B) described later can be used without limitation, but in general, methyl methacrylate, ethyl methacrylate, Methacrylic acid esters such as butyl methacrylate, pentyl methacrylate and cyclohexyl methacrylate; Acrylic acid esters such as methyl acrylate, ethyl acrylate, butyl acrylate, 2-ethylhexyl acrylate, cyclohexyl acrylate and benzyl acrylate; An acid; a single polymer such as acrylic acid or two or more kinds of copolymers are preferably used.

  Such a (meth) acrylic acid polymer may be a copolymer of the main monomer of the above (meth) acrylic monomer and another polymerizable monomer copolymerizable therewith. Examples of such other polymerizable monomers include diene compounds such as 1,3-butadiene, 2,3-dimethylbutadiene, and isoprene; aromatic vinyl compounds such as styrene and α-methylstyrene; acrylonitrile, methacrylonitrile, and the like. And vinyl cyanide compounds.

  These (meth) acrylic acid-based polymers preferably have a softening point of 0 ° C. or higher, more preferably 25 to 140 ° C. because if the softening point is too low, particles aggregate and lead to a decrease in dispersibility. It preferably has a softening point.

  In the core-shell type particles, the core part is generally formed of a single kind of silicone, but may be provided as a laminated part of two or more layers by changing the kind of silicone. Similarly, the entire shell portion may be formed of a single (meth) acrylic acid polymer, or may be provided as a laminate of two or more layers by changing the type of the (meth) acrylic acid polymer. good. Furthermore, if it is a thin layer that does not affect the effect, an intermediate layer made of another material different from these is provided between the core made of silicone and the shell made of a (meth) acrylic acid polymer. May be. Examples of the intermediate layer include non-crosslinked silicone, a polymer of the diene compound, a polymer of the aromatic vinyl compound, and the like.

  The shape of the core-shell type particle is not particularly limited, but is usually spherical or substantially spherical. The particle diameter is not particularly limited, but in order to more effectively express the effects of the present invention, the average particle diameter is preferably in the range of 10 to 500 nm, more preferably 50 to 300 nm. Here, the average particle size is an enlarged image using a scanning electron microscope (SEM), and measures the longest diameter and the shortest system of particles. 30 or more, and more precisely, a value obtained as an average value of particle diameters of 100 or more.

  In such a core-shell type particle, the thickness of the shell portion is not particularly limited, but from the viewpoint of imparting both impact resistance and coloring resistance to the curable material in a balanced manner, the thickness is 5 to 40 nm. It is preferably 15 to 35 nm, and most preferably 25 to 32 nm.

  In the present invention, the method for producing the core-shell type particles is not particularly limited, and may be produced by any method, but generally, as described above, the surface of the silicone particles forming the core part is made polymerizable. After treatment with a silane coupling agent having a heavy bond, a method of polymerizing by adding a (meth) acrylic monomer, or a polymer particle such as a (meth) acrylic group on the particle surface as a silicone particle serving as a core part. Examples include a method in which a side chain having a saturated group is bonded, and then a (meth) acrylic acid monomer is polymerized while reacting with the polymerizable unsaturated group. The latter method is more preferred, and specific examples of such a method include, for example, producing a core of silicone particles by emulsion polymerization from octamethylcyclotetrasiloxane, methyltrimethoxysiloxane, and methacryloxypropyltrimethoxysilane, A method of polymerizing methyl methacrylate while reacting with methacryloxy group derived from methacryloxypropyltrimethoxysilane is mentioned. Details of such a method are as disclosed in JP-A-4-277507. Further, core-shell type particles that satisfy these requirements are already commercially available, such as “Genio Pearl” (manufactured by Asahi Kasei Wacker Silicone), and can be easily obtained.

  In the curable material of the present invention, the content of the core / shell type particles as the component (A) depends on the physical properties of dental materials such as denture bases, denture lining materials and composite resins made by the curable material. There is no limitation as long as it is not impaired, but for the effect of the present invention more effectively, the component (B) (meth) acrylic acid monomer is 100 parts by weight with respect to 100 parts by weight. The amount is preferably 10 to 50 parts by weight, more preferably 13 to 35 parts by weight.

As the (meth) acrylic acid monomer of the component (B) in the present invention, known ones that can be generally used for dental materials can be used without any limitation. Specific examples include the monomers shown in the following a) to d).
A) Monofunctional (meth) acrylic acid monomers Methacrylates such as methyl methacrylate, ethyl methacrylate, isopropyl methacrylate, hydroxyethyl methacrylate, tetrahydrofurfuryl methacrylate, glycidyl methacrylate, and acrylates corresponding to these methacrylates; or acrylic acid, methacrylic acid Acid, p-methacryloyloxybenzoic acid, N-2-hydroxy-3-methacryloyloxypropyl-N-phenylglycine, 4-methacryloyloxyethyl trimellitic acid and its anhydride, 6-methacryloyloxyhexamethylenemalonic acid, 10 -Methacryloyloxydecamethylenemalonic acid, 2-methacryloyloxyethyl dihydrogen phosphate, 10-methacryloyloxy Sidecamethylene dihydrogen phosphate, etc. b) Bifunctional (meth) acrylic acid monomers (I) Aromatic compounds 2,2-bis (methacryloyloxyphenyl) propane, 2,2-bis [4- ( 3-methacryloyloxy) -2-hydroxypropoxyphenyl] propane (hereinafter abbreviated as bis-GMA), 2,2-bis (4-methacryloyloxyphenyl) propane, 2,2-bis (4-methacryloyloxypolyethoxy) Phenyl) propane, 2,2-bis (4-methacryloyloxydiethoxyphenyl) propane), 2,2-bis (4-methacryloyloxytetraethoxyphenyl) propane, 2,2-bis (4-methacryloyloxypentaethoxyphenyl) ) Propane, 2,2-bis (4-methacryloyl) Oxydipropoxyphenyl) propane, 2 (4-methacryloyloxydiethoxyphenyl) -2 (4-methacryloyloxydiethoxyphenyl) propane, 2 (4-methacryloyloxydiethoxyphenyl) -2 (4-methacryloyloxyditriethoxyphenyl) ) Propane, 2 (4-methacryloyloxydipropoxyphenyl) -2- (4-methacryloyloxytriethoxyphenyl) propane, 2,2-bis (4-methacryloyloxypropoxyphenyl) propane, 2,2-bis (4- Methacryloyloxyisopropoxyphenyl) propane and acrylates corresponding to these methacrylates; 2-hydroxyethyl methacrylate, 2-hydroxypropyl methacrylate, 3-chloro-2-hydroxypro (II) Aliphatic compounds based on methacrylates such as methacrylates or vinyl monomers having —OH groups such as acrylates corresponding to these methacrylates. Ethylene glycol dimethacrylate, diethylene glycol dimethacrylate, triethylene glycol dimethacrylate (hereinafter, 3G), butylene glycol dimethacrylate, neopentyl glycol dimethacrylate, propylene glycol dimethacrylate, 1,3-butanediol dimethacrylate, 1,4-butanediol dimethacrylate, 1,6-hexanediol dimethacrylate and these Acrylates corresponding to other methacrylates; 2-hydroxyethyl methacrylate, 2-hydroxypropyl methacrylate, 3-chloro-2 Methacrylates such as hydroxypropyl methacrylate or vinyl monomers having —OH groups such as acrylates corresponding to these methacrylates, acrylic anhydride, methacrylic anhydride, 1,2-bis (3-methacryloyloxy-2-hydroxypropoxy) ethyl , Di (2-methacryloyloxypropyl) phosphate, etc.) trifunctional (meth) acrylic acid monomers, such as trimethylolpropane trimethacrylate, trimethylolethane trimethacrylate, pentaerythritol trimethacrylate, trimethylolmethane trimethacrylate, and the like, and Acrylates corresponding to these methacrylates d) Tetrafunctional (meth) acrylic acid monomers Tetramethylol methane tetramethacrylate, penta Risuri tall tetramethacrylate, acrylates corresponding to pentaerythritol tetraacrylate and their methacrylate.

  These (meth) acrylic acid monomers can be used alone or in combination of two or more. In particular, when using a combination of a monofunctional compound and a bifunctional compound or a trifunctional compound or more, mechanical properties such as strength and durability of the cured product obtained by blending a large amount of the bifunctional compound or the trifunctional compound or more. Is also preferable because it can be improved.

  The polymerization initiator for component (C) used in the present invention can be used without any limitation as long as it generates radicals by heating or light irradiation, and an effective amount is used for proceeding polymerization. Further, an effective amount of those capable of generating radicals under room temperature conditions upon contact with a tertiary amine or the like may be used.

  An organic peroxide is illustrated as a substance which generates a radical by heating or contact with a tertiary amine. Specific examples of typical organic peroxides include benzoyl peroxide (hereinafter abbreviated as BPO), 2,4-dichlorobenzoyl peroxide, dilauroyl peroxide, and the like.

  Suitable amount of these organic peroxides varies depending on the type of organic peroxide to be used, and thus cannot be unconditionally limited, but is preferably 0.05 to 5 parts by weight relative to 100 parts by weight of component (B) More preferably, it is the range of 0.1-3 weight part.

  Further, known compounds are not particularly limited and used as the tertiary amine for generating radicals upon contact with these organic peroxides. Specific examples of suitably used tertiary amine compounds include N, N-dimethylaniline, N, N-diethylaniline, N, N-dipropylaniline, N, N-dibutylaniline, N-methyl, Anilines such as N-β-hydroxyethylaniline, N, N-dimethyl-p-toluidine, N, N-diethyl-p-toluidine, N, N-dipropyl-p-toluidine, N, N-dibutyl-p- Toluidines such as toluidine, p-tolyldiethanolamine, p-tolyldipropanolamine, N, N-dimethyl-anisidine, N, N-diethyl-p-anisidine, N, N-dipropyl-p-anisidine, N, N- Anisidines such as dibutyl-p-anisidine, morpholines such as N-phenylmorpholine and N-tolylmorpholine, bis (N, N-dimethylaminophenyl) methane, bis (N, N-dimethylaminophenyl) ether and the like. These amine compounds may be used as salts with organic acids such as hydrochloric acid, phosphoric acid, acetic acid and propionic acid. Among the above tertiary amine compounds, N, N-diethyl-p-toluidine, N, N-dipropyl-p-toluidine, p-tolyldiethanolamine, p from the viewpoint of high polymerization activity and low irritation and low odor. -Tolyldipropanolamine is preferably used.

  The amount of the tertiary amine compound used is preferably 0.1% by weight relative to 100 parts by weight of component (B). The range is from 05 to 5 parts by weight, more preferably from 0.1 to 3 parts by weight.

  Specific examples of the combination of the organic peroxide and the tertiary amine compound include BPO / N, N-diethyl-p-toluidine, BPO / N, N-dipropyl-p-toluidine. , BPO / p-tolyldiethanolamine, BPO / p-tolyldipropanolamine and the like. In particular, when long-term storage is required in a state where a tertiary amine compound is mixed with a radical polymerizable monomer, BPO / N, N-diethyl-p-toluidine, BPO / N, N are used from the viewpoint of storage stability. The combination of -dipropyl-p-toluidine is most preferred.

  As the photopolymerization initiator, a known initiator system such as α-diketone-reducing agent, ketal-reducing agent, thioxanthone-reducing agent and the like is preferably used. Examples of A-diketones include camphorquinone, benzyl, 2,3-pentadione, and 3,4-heptadione. Examples of the ketal include benzyl dimethyl ketal, benzyl diethyl ketal, and benzyl (2-methoxyethyl ketal). Examples of thioxanthone include thioxanthone, 2,4-dimethylthioxanthone, 2,4-diethylthioxanthone, and 2-chlorothioxanthone. The reducing agent as one component of the photopolymerization initiator includes tertiary amines such as 2- (dimethylamino) ethyl methacrylate, ethyl 4-dimethylaminobenzoate and N-methyldiethanolamine, lauryl aldehyde, dimethylaminobenzaldehyde, terephthalate Examples include aldehydes such as aldehyde, 2-mercaptobenzoxazole, 1-decanethiol, thiosalicylic acid, and thiobenzoic acid.

  Suitable amount of these photopolymerization initiators varies depending on the type of photopolymerization initiator used, and thus cannot be generally limited, but is preferably 0.05 to 5 parts by weight relative to 100 parts by weight of component (B) More preferably, it is the range of 0.1-3 weight part.

  Further, the curable material of the present invention is used as a dental material used in the oral cavity, specifically, denture base curing such as denture base resin and denture base lining material. Materials, temporary sealing materials, composite resins, dental room temperature polymerization resins, orthodontic materials, artificial teeth, and the like. Optimum applications include denture base resins. Here, the denture base means a portion that holds the artificial tooth in the denture and is in direct contact with the oral mucosa. In the denture itself, not only the part directly in contact with the oral mucosa, but also a repair material lining the denture base for dentures that are incompatible in the oral cavity during use, such as denture base lining materials and mucous membranes An adjustment material is also included in the denture base.

  When the curable material of the present invention is used as a resin or a denture base lining material, the composition of the curable material includes a reinforcing material, in addition to the core-shell type particles, in order to improve the strength. It is preferable to contain the filler (component (D)) which becomes. As the filler, known materials that can be generally used for dental materials can be used. The filler may be an organic filler or an inorganic filler. As long as it is made of a rigid organic material that can be used as a reinforcing agent, it may be made of a (meth) acrylic acid-based polymer. Even if it is an acrylic acid-type polymer, the above-mentioned problem of coloring resistance does not appear so much. An inorganic filler is preferably used as the filler if the effect of coloring resistance is more fully exhibited.

  As the organic filler used in the present invention, generally available resin polymers such as poly (meth) acrylate, polycarbonate, and polyester are used without limitation. In general, powders of polymethyl methacrylate, polyethyl methacrylate, polybutyl methacrylate, polystyrene and copolymers thereof are preferably used in terms of chemical stability, transparency and the like. Among these, polymethyl methacrylate and ethyl methacrylate are particularly preferable because they are inexpensive and easy to handle.

  The kind of the inorganic filler used in the present invention is not particularly limited, and can be selected from reinforcing materials and fillers added to general resin compositions. Specifically, calcium carbonate, calcium sulfate, magnesium oxide, barium carbonate, barium sulfate, titanium oxide, potassium titanate, barium titanate, aluminum hydroxide, magnesium hydroxide, meteorite powder, glass powder, diatomaceous earth, silica, Examples include calcium silicate, talc, alumina, bentonite, zeolite, kaolin clay, mica, and quartz glass. Silica and alumina are preferably used from the viewpoints of ease of handling, compatibility with liquid materials, solubility in saliva (elution), and the like.

  The particle size of such a filler is not particularly limited, but preferably has a volume average particle size of 100 μm or less, and more preferably 0.01 to 40 μm from the viewpoint of kneadability. Of course, you may use together 2 or more types of organic or inorganic fillers from which a material, an average particle diameter, etc. differ.

  The filler can be added without particular limitation as long as it does not interfere with the effect of the present invention, but if it is too small, the prepared denture base, the strength of the lining material may be low, and if too much, Since it may become difficult to mix uniformly when producing, it is preferable that it is 1-300 weight part with respect to 100 weight part of component (B), and it is more preferable that it is 10-250 weight part.

In the present invention, the packaging form of the dental curable material is not particularly limited,
All components may be kneaded to form a single paste type, a powder material containing core / shell type particles, a liquid material containing a (meth) acrylic acid monomer, and a polymerization initiator is at least one of the above powder material and liquid material It may be packaged in a powder type or a paste / paste type contained in either one. Since the core-shell type particle of component (A) is a (meth) acrylic acid polymer, the shell part is familiar with the (meth) acrylic acid monomer of component (B), and kneading operability is improved. Since it is extremely excellent, in the case of the powder type, a remarkable effect of improving operability is exhibited.

  When the curable material of the present invention is used as a denture base resin, a powder liquid type is preferable from the viewpoint of storage stability, and the components (A), (C), and (D) are the main components. It is preferable to comprise with the powder component made into and the liquid component which has a component (B) as a main component. These are used by mixing and kneading a predetermined amount of a powder component and a liquid component at the time of use.

  In addition, additives, such as a pigment and a fragrance | flavor, can also be added to the dental curable composition of this invention within the range which does not inhibit the effect of this invention.

EXAMPLES The present invention will be specifically described below with reference to examples, but the present invention is not limited to these examples. The materials used in each example and comparative example are as follows.
(A) Core-shell type particles ・ Geniopearl P52 (average particle size 150 nm, core part: silicone, softening point −130 ° C., shell part: polymethyl methacrylate, softening point 120 ° C., thickness 30 nm, manufactured by Asahi Kasei Wacker Silicone)
・ Geniopearl P22 (High purity product of core / shell type particles with the same properties as Geniopearl P52)
(B) (Meth) acrylic acid monomer ・ Methyl methacrylate monomer (abbreviated as “MMA”, manufactured by Wako Pure Chemical Industries, Ltd.)
・ 1,9-nonanediol dimethacrylate (abbreviated as “ND”, manufactured by Aldrich)
Β-methacryloyloxyethyl propionate (abbreviated as “HPr”; manufactured by Shin-Nakamura Chemical)
2,2-bis [4- (3-methacryloyloxy) -2-hydroxypropoxyphenyl] propane (abbreviated as “Bis-GMA”)
・ Triethylene glycol dimethacrylate (abbreviated as “3G”, manufactured by Wako Pure Chemical Industries, Ltd.)
(C) Polymerization initiator • Benzoyl peroxide (abbreviated as “BPO”; manufactured by Kawaguchi Chemical)
・ Diethyl-p-toluidine (abbreviated as “PEAT”)
・ Camphorquinone (abbreviated as “CQ”, manufactured by Wako Pure Chemical Industries, Ltd.)
N, N-dimethyl-P-toluidine (abbreviated as “DMPT”, manufactured by Wako Pure Chemical Industries, Ltd.)
(D) Filler Polymethylmethacrylate (abbreviated as “PMMA”, average particle size 25 μm, manufactured by Negami Industrial Co., Ltd.)
Polyethyl methacrylate (abbreviated as “PEMA”. Average particle size 35 μm, manufactured by Negami Kogyo)
・ Spherical silica-zirconia filler (3-glycidyloxypropyltrimethoxysilane treatment, average particle size 0.4 μm)
Furthermore, in Examples 1-8 and Comparative Examples 1-4, evaluation of the dental curable material was performed by the following method, and the average value was recorded by measuring or evaluating the same sample three times.

  (1) Fracture toughness: A prismatic cured body of 2 mm × 4 mm × 20 mm is produced, a crack of about 2 mm is made with a cutter, and a three-point bending sample piece with a notch on one side is produced. This specimen is mounted on a testing machine (manufactured by Shimadzu Corp., Autograph AG-1), and a three-point bending test is performed at a distance between supporting points of 16 mm and a crosshead speed of 1.0 mm / min. Calculated.

(2) Color resistance: A test piece of 10 mm × 10 mm × 2 mm was produced. The obtained cured product was measured for L ^* , a ^* , and b ^* before coloring with a color difference meter (TC-1800MKII, manufactured by Tokyo Denshoku). Thereafter, the test pieces were each immersed in 100 ml of 5.0 wt% aqueous coffee solution and immersed at 40 ° C. for 24 hours. After immersion, washing with water, dried, L ^* again a color difference meter, ^a *, measured b ^*, the ^{difference, △ L *, △ a *} , △ b * than, coloring amount using the following equation (△ E ^* )

△ E ^* = (△ L ^{* 2} + △ a ^{* 2} + △ b ^{* 2} ) ^1/2
(3) Operability: In the case of a powder liquid type, a necessary amount of each of powder and liquid was taken, and a total of 6 g was kneaded until uniform, and the kneadability was evaluated from A to X according to the following criteria.
○: 10 seconds or less until uniform Δ: Strong force is required for kneading, 10 seconds or more until uniform ×: Powder and liquid do not mix and become uniform Note that (1) Fracture toughness and (2) In the test for resistance to coloration, the method for producing a cured product is, in the case of heat polymerization (Examples 1 to 4, Comparative Examples 1 and 3 to 6), after mixing a predetermined amount of powder and liquid, The paste was poured into a mold of a predetermined size, the upper and lower sides were pressed with a plastic sheet, polymerized in 100 ° C. water for 60 minutes, and then immersed in 37 ° C. water for 24 hours to obtain a test piece. In the case of room temperature polymerization (Examples 5 to 6, Comparative Examples 2 and 7), after mixing a predetermined amount of powder and liquid, the paste is poured into a mold of a predetermined size, and the upper and lower sides are sandwiched between plastic sheets and pressed. Then, after curing, it was immersed in water at 37 ° C. for 24 hours to obtain a test piece. In the case of photopolymerization (Examples 7 to 8), after mixing a predetermined amount of powder and liquid, the paste is poured into a mold of a predetermined size, and the upper and lower sides are pressed with a plastic sheet, and a light irradiator ( After curing by irradiating with light for 10 minutes in Tokuyama (TOKUSO B-L), the specimen was immersed in water at 37 ° C. for 24 hours.

Example 1
Powder components and liquid components were prepared with the compositions shown in Table 1. This powder and liquid were kneaded at equal weights, and the above physical properties were evaluated. The results are shown in Table 3.

As shown in Table 3, the fracture toughness was 2.1 MPa / m ^1/2 , ΔE ^* in the coffee coloring test was 2.9, and the operability was also good. From the above results, by adding core-shell type particles having a core portion made of silicone and a shell portion made of a (meth) acrylic acid-based polymer that forms a surface layer to the dental curable material, high resistance to resistance is obtained. It was found that impact resistance, color resistance, and good operability can be obtained.

Examples 2-6
In the same manner as in Example 1, powders and liquids having the respective compositions shown in Table 1 were prepared and evaluated. These evaluation results are shown in Table 3, respectively.

  As shown in Table 3, it was found that the dental curable material of the present invention has high impact resistance and coloring resistance, and is excellent in operability.

Example 7
Pastes having the compositions shown in Table 2 were prepared, and fracture toughness and coloring resistance were evaluated. Since it is a paste type, operability evaluation was excluded. These evaluation results are shown in Table 3, respectively.

As shown in Table 3, the fracture toughness was 2.7 MPa / m ^1/2 , and ΔE ^* in the coffee coloring test was 1.1, and the dental curable material of the present invention was a paste type. It was found to have high impact resistance and color resistance.

Example 8
As in Example 7, pastes having the compositions shown in Table 2 were prepared and evaluated. These evaluation results are shown in Table 3, respectively.

  As shown in Table 3, it was found that the dental curable material of the present invention has high impact resistance and coloring resistance, and is excellent in operability.

Comparative Example 1
In the same manner as in Example 1, powders and liquids having the respective compositions shown in Table 1 were prepared and evaluated. These evaluation results are shown in Table 3, respectively.

  As shown in Table 3, sufficient impact resistance, coloring resistance, and excellent operability were not obtained.

Comparative Example 2
According to the example shown in Example 1 of JP-A-2005-60712, the core part is a (meth) acrylic acid polymer obtained by polymerizing monomers of methyl methacrylate and n-butyl methacrylate, and the shell part is methyl methacrylate. The core-shell type comparative particle which is the (meth) acrylic acid type polymer which superposed | polymerized n-butylmethacrylate and methacrylic acid and whose average particle diameter is 350 nm was manufactured.

  Using the obtained core-shell type comparative particles, the powders and liquids of the respective compositions shown in Table 1 were prepared and evaluated in the same manner as in Example 1. These evaluation results are shown in Table 3, respectively.

  As shown in Table 3, the impact resistance is improved by adding the core-shell type comparative particles, and the shell part is a (meth) acrylic acid polymer, so the operability is excellent. Since it is a (meth) acrylic acid polymer, color resistance was not sufficient.

Comparative Example 3
In the same manner as in Example 1, powders and liquids having respective compositions shown in Table 1 were prepared and evaluated. These evaluation results are shown in Table 3, respectively.

  As shown in Table 3, sufficient impact resistance, coloring resistance, and excellent operability were not obtained.

Comparative Example 4
Pastes having the compositions shown in Table 2 were prepared, and fracture toughness and coloring resistance were evaluated. Since it is a paste type, operability evaluation was excluded. These evaluation results are shown in Table 3, respectively.

  As shown in Table 3, sufficient impact resistance and coloring resistance were not obtained.

Claims (4)

(A) Core / shell type particles (B) (meth) acrylic acid monomer having a core part made of crosslinked silicone and a shell part made of a (meth) acrylic acid polymer forming a surface layer, and (C) polymerization A dental curable material comprising an initiator. The dental curable material according to claim 1, wherein the average particle diameter of the core-shell type particles is 10 to 500 nm and the thickness of the shell portion is 5 to 40 nm. The dental curable material according to claim 1 or 2, further comprising (D) a filler other than (A) the core-shell type particles. It is for denture base manufacture, The dental curable material as described in any one of Claims 1-3.