JP2019116431A - Water-resistant mill blank - Google Patents

Abstract

To provide a dental mill blank having excellent water resistance, that can suppress a deterioration of its mechanical strength, even in an environment where water is present, e.g. in the mouth, and a method of producing the same.SOLUTION: A dental mill blank has a drop rate of three point bending strength of 20% or less when immersed in water at 37°C for one week.SELECTED DRAWING: None

Description

  The present invention relates to a dental mill blank and a method of manufacturing the dental mill blank. More specifically, inlays, onlays, veneers, crowns, bridges, abutments, dental posts, dentures, dentures, implant members (fixtures, abutments), for example, by cutting with a dental CAD / CAM system. And a method of manufacturing the dental mill blank.

  In recent years, CAD / CAM systems in which dental prostheses such as inlays and crowns are designed by a computer and cut and manufactured by a milling apparatus have become widespread. In general, a dental mill blank, which is a material to be cut used in a CAD / CAM system, is a mill blank portion to be subjected to cutting, and a support portion which protrudes from the mill blank portion and fixes the mill blank portion to a milling apparatus. And.

  A ceramic material has been generally used as a material of the mill blank from the viewpoint of aesthetics. However, since dental prostheses made from ceramic mill blanks are brittle materials with high hardness, they not only cause damage to the mating teeth, but also have problems such as chipping caused by impact of cutting or occlusion The

  In order to solve such a subject, examination of the mill blank part which consists of a composite material containing a polymer and an inorganic filler is performed recently. The mill blank has a moderate hardness that does not damage the opposing teeth, and is excellent in impact resistance even in a crown shape, and is being processed into a dental prosthesis and is beginning to be used clinically.

  As a method for producing a mill blank portion composed of the composite material, Patent Documents 1 to 5 disclose uniform paste-like compositions (composite resin) obtained by mixing and kneading an inorganic filler and a polymerizable monomer. (4) is poured into a mold and subjected to polymerization such as heat polymerization or photopolymerization in the mold to obtain a method of obtaining a mill blank portion which is a cured product. In the method of obtaining the mill blank portion from the composite resin, the composite resin before polymerization needs to have a somewhat high fluidity, and it is difficult to increase the blending ratio of the inorganic filler. Therefore, the dental prosthesis obtained from the mill blank portion described in the patent document has insufficient mechanical strength, abrasion resistance and surface lubricity.

  On the other hand, according to Patent Document 6, after the molded body of the inorganic filler and the composition containing the polymerizable monomer are brought into contact with each other to impregnate the molded body with the polymerizable monomer, the polymerizable unit amount is obtained. A method of producing a mill blank by polymerizing the body is disclosed. From the mill blank portion obtained by such a method, it is possible to obtain a dental prosthesis which is excellent in mechanical strength, abrasion resistance, surface lubricity, and abrasion resistance of mating teeth.

  On the other hand, in recent years, higher mechanical strength is desired for dental prostheses used in areas to which strong occlusal force is applied, such as, for example, molars and premolars, but generally, composite resins have strength due to water absorption. Is known to be reduced, and those excellent in water resistance are required.

  As an attempt among them, a coating agent containing as a active ingredient a silicone oligomer containing a fluoroalkyl group at both ends of the main chain in order to suppress discoloration and accumulation of plaque on the surface of resin-based dental restorative materials ( For example, see Patent Document 7), denture base lining material and coating composition (see, eg, Patent Documents 8 to 9) containing fluorine-containing (meth) acrylate as part of monomers, polar groups such as acrylic acid, etc. A dental material to which a fluorine-based material such as a coating composition containing a fluorine-containing polymer obtained by copolymerizing a monomer having a fluorine atom and a monomer having a fluorine atom (see, for example, Patent Document 10) is proposed . However, although these dental materials are effective with materials that function as monomers as main components (for example, an adhesive, a coating agent), resin-based materials in which the inorganic filler is mainly and the amount of monomers is limited. The problem was that the effect was small.

Japanese Patent Publication No. 2003-529386 Japanese Patent Application Laid-Open No. 10-323353 JP 2012-87204 A International Publication No. 2012/042911 International Publication No. 2009/154301 International Publication No. 2014/021343 JP-A-5-155730 JP 2000-312689 A JP 2003-95838 Japanese Patent Publication No. 10-510531

  Therefore, the present invention provides a dental mill blank excellent in water resistance that can suppress a decrease in mechanical strength even in an environment where water is present, such as in the oral cavity, and a simple manufacturing method thereof. With the goal.

The present invention includes the following inventions.
[1] A dental mill blank, wherein the reduction rate of three-point bending strength when immersed in water at 37 ° C. for one week is 20% or less.
[2] The dental mill blank according to the above [1], which has a contact angle to water of 60 ° or more [3] inorganic surface-treated with a silane coupling agent (b-1) having a fluorine-containing organic group The dental mill blank according to the above [1] or [2], which comprises a filler.
[4] The silane coupling agent (b-1) is represented by the following general formula (I)
R ¹ _n -SiX _4-n (I)
[Wherein, R ¹ is a C ¹ to C 12 perfluorohydrocarbon group or a C ¹ to C 12 hydrocarbon group having a C ¹ to C 6 perfluoroalkyl group, and X is a C ¹ to C ¹ carbon atom] 4 represents an alkoxy group, an acetoxy group, a hydroxyl group, a halogen atom, or a hydrogen atom, and n is an integer of 0 to 3, provided that R ¹ and X each may be the same or different . ]
The dental mill blank as described in said [3] which is a silane coupling agent represented by these.
[5] The above-mentioned [3], wherein the inorganic filler is further surface-treated with a silane coupling agent (b-2) having a functional group capable of copolymerizing with the polymerizable monomer. Or dental mill blank in any one of [4].
[6] a step of press-forming an inorganic filler to obtain an inorganic filler compact,
A step of bringing the inorganic filler molding into contact with the polymerizable monomer (c) and the polymerization initiator (d) for polymerization and curing, and the inorganic filler and / or the inorganic filler molding, Including the step of surface treatment with a silane coupling agent (b-1) having a group
The manufacturing method of dental mill blanks.
[7] A step of surface-treating an inorganic filler with a silane coupling agent (b-1) having a fluorine-containing organic group,
Kneading the inorganic filler and the polymerizable monomer (c) to obtain a paste, and filling the paste into a mold, pressing and compressing, and then polymerizing and curing.
The manufacturing method of dental mill blanks.
[8] The silane coupling agent (b-1) is represented by the following general formula (I)
R ¹ _n -SiX _4-n (I)
[Wherein, R ¹ is a C ¹ to C 12 perfluorohydrocarbon group or a C ¹ to C 12 hydrocarbon group having a C ¹ to C 6 perfluoroalkyl group, and X is a C ¹ to C ¹ carbon atom] 4 represents an alkoxy group, an acetoxy group, a hydroxyl group, a halogen atom, or a hydrogen atom, and n is an integer of 0 to 3, provided that R ¹ and X each may be the same or different . ]
The manufacturing method of the dental mill blank as described in said [6] or [7] which is a silane coupling agent represented by these.

  ADVANTAGE OF THE INVENTION According to this invention, the dental mill blank which has water repellency can be provided, and it becomes possible to suppress the reduction rate of 3 point | piece bending strength at the time of making it immersed in water of 37 degreeC for 1 week to 20% or less. In addition, the dental mill blank of the present invention is excellent in the density of the obtained inorganic filler compact and the initial bending strength because the slipperiness of the inorganic filler is improved.

  The dental mill blank of the present invention has a decrease in three-point bending strength of 20% or less when immersed in water at 37 ° C. for one week.

  The dental mill blank of the present invention has water repellency and can suppress the decrease in mechanical strength due to the penetration of water, so the rate of decrease in three-point bending strength when immersed in water at 37 ° C. for one week is It is 20% or less, preferably 15% or less, more preferably 10% or less, and still more preferably 8% or less. The method of measuring the reduction rate of the three-point bending strength will be described in detail in the following examples.

  The dental mill blank of the present invention preferably has a contact angle to water of 60 ° or more. Thereby, the fall of mechanical strength can be suppressed. The contact angle is more preferably 65 ° or more, further preferably 90 ° or more. The contact angle to water may be 170 ° or less, 150 ° or less, or 130 ° or less. In addition, the measuring method of this contact angle is demonstrated in detail in the below-mentioned Example.

  The dental mill blank of the present invention comprises an inorganic filler which is surface-treated with a silane coupling agent (b-1) having a fluorine-containing organic group (hereinafter referred to as a silane coupling agent (b-1)). Is preferred. Thereby, a dental mill blank is excellent in water resistance, and can suppress the fall of the mechanical strength in the environment where water exists like an intraoral area. Furthermore, since the slipperiness of the inorganic filler can be improved by surface-treating the inorganic filler with the silane coupling agent (b-1), inorganic filler molding obtained by press-molding the inorganic filler When a body is used, the density of the inorganic filler compact can be increased, and a dental mill blank excellent in initial bending strength can be obtained.

As the silane coupling agent (b-1), it is possible to further suppress the decrease in mechanical strength in the presence of water as in the oral cavity, and to further improve the slipperiness of the inorganic filler. From the point of view, the following general formula (I)
R ¹ _n -SiX _4-n (I)
[Wherein, R ¹ is a C ¹ to C 12 perfluorohydrocarbon group or a C ¹ to C 12 hydrocarbon group having a C ¹ to C 6 perfluoroalkyl group, and X is a C ¹ to C ¹ carbon atom] 4 represents an alkoxy group, an acetoxy group, a hydroxyl group, a halogen atom, or a hydrogen atom, and n is an integer of 0 to 3, provided that when R ¹ and X are plural, they may be the same or different. ]
It is preferred to use one represented by

Examples of the perfluorohydrocarbon group having 1 to 12 carbon atoms of R ¹ include a perfluoroalkyl group, a perfluoroalkenyl group, a perfluoroalkynyl group, a perfluorocycloalkyl group, a perfluoroaryl group, a perfluoroaralkyl group and the like. Perfluoroalkyl and perfluoroaryl groups are preferred. The perfluoroalkyl group may be linear or branched. The carbon number of the perfluoroalkyl group is not particularly limited, and may be 1 to 10, or 1 to 6. As a perfluoroalkyl group, for example, perfluoromethyl group, perfluoroethyl group, perfluoropropyl group, perfluorobutyl group, perfluoropentyl group, perfluorohexyl group, perfluoroheptyl group, perfluorooctyl group, perfluorooctyl group Fluorononyl group, perfluorodecyl group, perfluoroundecyl group, perfluorododecyl group and the like can be mentioned. As a perfluoro aryl group, a pentafluoro phenyl group, a hepta fluoro 1-naphthyl group, and a hepta fluoro 2-naphthyl group are mentioned.

Hydrocarbon group having 1 to 12 carbon atoms having a perfluoroalkyl group having 1 to 6 carbon atoms of R ¹ may be linear, may be branched. Among the foregoing perfluoroalkyl groups, those having 1 to 6 carbon atoms can be mentioned. It does not specifically limit as carbon number of the said hydrocarbon group part, It may be 1-10, and may be 1-6. As said hydrocarbon group, an alkyl group, an alkenyl group, an alkynyl group, a cycloalkyl group, an aryl group, an aralkyl group etc. are mentioned, An alkyl group is preferable. As an alkyl group of the said hydrocarbon group part, a methyl group, an ethyl group, n-propyl group, isopropyl group, n-butyl group, an isobutyl group, a sec-butyl group, 2-methylpropyl group, a tert- butyl group is mentioned, for example N-pentyl, isopentyl, sec-pentyl, neopentyl, 1-ethylpropyl, 1,1-dimethylpropyl, 1,2-dimethylpropyl, n-hexyl, 1-methylpentyl, 2-methylpentyl group, 3-methylpentyl group, 4-methylpentyl group (isohexyl group), 1-ethylbutyl group, 2-ethylbutyl group, 1,1-dimethylbutyl group, 1,2-dimethylbutyl group, 1, 3-dimethylbutyl group, 1,4-dimethylbutyl group, 2,2-dimethylbutyl group, 2,3-dimethylbutyl group, 3,3-dimethylbutyl group, 1 -Ethyl-2-methyl-propyl group, 1,1,2-trimethylpropyl group, n-heptyl group, 2-methylhexyl group, n-octyl group, isooctyl group, tert-octyl group, 2-ethylhexyl group, 3 -A methyl heptyl group etc. are mentioned. The alkoxy group having 1 to 4 carbon atoms of X may be linear or branched, and examples thereof include a methoxy group, an ethoxy group, an n-propoxy group, an isopropoxy group, and an n-group. A butoxy group, a sec-butoxy group, a tert-butoxy group etc. are mentioned. As X, a C1-C4 alkoxy group is preferable.

  As the silane coupling agent (b-1), for example, 1,1,1-trifluoro-3- [dimethoxy (methyl) silyl] propane, dimethoxy (methyl) (3,3,3-trifluoropropyl) silane Trimethoxy (1H, 1H, 2H, 2H-nonafluorohexyl) silane, trimethoxy (1H, 1H, 2H, 2H-heptadecafluorodecyl) silane, trimethoxy (1H, 1H, 2H, 2H-tridecafluoro-n-) Octyl) silane, trimethoxy (11-pentafluorophenoxyundecyl) silane, triethoxy (pentafluorophenyl) silane, trimethoxy (pentafluorophenyl) silane, trichloro [3- (pentafluorophenyl) propyl] silane, trichloro (1H, 1H , 2H, 2H-heptadecaful Rodeshiru) silane, trichloro (1H, 1H, 2H, 2H- tridecafluoro -n- octyl) silane. Among them, dimethoxy (methyl) (3,3,3-trifluoropropyl) silane, trimethoxy (1H, 1H, 2H, 2H-heptadecafluorodecyl) silane, trimethoxy (11-pentafluorophenoxyundecyl) silane, 1 Preferred are 1,1,1-trifluoro-3- [dimethoxy (methyl) silyl] propane, trimethoxy (1H, 1H, 2H, 2H-tridecafluoro-n-octyl) silane, and trimethoxy (pentafluorophenyl) silane.

  In the present invention, the inorganic filler is a silane coupling agent (b-2) (hereinafter referred to as a silane cup) having a functional group capable of copolymerizing with the polymerizable monomer together with the silane coupling agent (b-1). It is preferable to surface-treat with a ring agent (b-2). As a functional group which can be copolymerized with a polymerizable monomer, a (meth) acroyloxy group, a vinyl group, and a glycidoxy group are preferable, and a (meth) acroyloxy group is more preferable. As the silane coupling agent (b-2), for example, ω- (meth) acryloyloxyalkyltrimethoxysilane [the number of carbons between a (meth) acryloyloxy group and a silicon atom: 3 to 12], ω- (Meth) acryloyloxyalkyltriethoxysilane [C3 to C12 between (meth) acryloyloxy group and silicon atom], vinyltrimethoxysilane, vinyltriethoxysilane, vinyltriacetoxysilane, γ-glycid And xylpropyltrimethoxysilane and the like. Among these, γ-methacryloyloxypropyltrimethoxysilane is more preferably used. In addition, when using together two types of silane coupling agents (b-1) and (b-2), both may be simultaneously put into a reaction system, and even if it carries out the process of surface treatment separately Good.

  The content of each of the silane coupling agents (b-1) and (b-2) can be adjusted according to the specific surface area of the inorganic particles (a), and is not particularly limited. From the viewpoint of water repellency and the like, it is preferable to use 0.010 to 0.035 parts by mass with respect to 100 parts by mass of the inorganic particles (a). Furthermore, when content of a silane coupling agent (b-1) is 0.015 mass part or more with respect to 100 mass parts of inorganic particles (a), water repellency can fully be provided to an inorganic particle, and water It is preferable because the decrease in mechanical strength in the presence can be sufficiently suppressed, and more preferably 0.020 parts by mass or more. On the other hand, when the content of the silane coupling agent (b-1) is 0.035 parts by mass or less with respect to 100 parts by mass of the inorganic particles (a), a functional group capable of copolymerizing with the polymerizable monomer Since the room for reaction of the coupling agent (b-2) which has these remains sufficiently, it is preferable at the point which sufficient mechanical strength is obtained.

  The shape of the dental mill blank of the present invention is not particularly limited, and examples thereof include rectangular prisms such as rectangular parallelepiped, cube, regular pentagonal prism, regular hexagonal prism, regular octagonal prism, and cylindrical.

  The dental mill blank of the present invention is a pH adjuster, an ultraviolet absorber, an antioxidant, a polymerization inhibitor, a colorant, a pigment, an antibacterial agent, an X-ray contrast agent, a thickener, a fluorescent agent, etc. according to the purpose. And additives of the following. As the pigment, known pigments used in dental compositions are used without any limitation. Such pigments may be either inorganic pigments and / or organic pigments, and examples of inorganic pigments include chromate salts such as yellow lead, zinc yellow and barium yellow; ferrocyanides such as bitumen; silver tin, cadmium yellow, Sulfides such as zinc sulfide, antimony white, cadmium red, sulfates such as barium sulfate, zinc sulfate, strontium sulfate, etc .; zinc oxide, titanium oxide, iron oxide (bengal), iron oxide black, iron oxide yellow, chromium oxide etc Oxides such as aluminum hydroxide; silicates such as calcium silicate and ultramarine blue; and carbons such as carbon black and graphite. Examples of organic pigments include nitroso-based pigments such as naphthol green B and naphthol green Y; nitro-based pigments such as naphthol S and lisol fast yellow 2G, permanent red 4R, brilliant fast scarlet, Hansa yellow and benzidine yellow Based pigments; sparingly soluble azo pigments such as lisole red, lake red C, lake red D; soluble azo pigments such as brilliant carmine 6B, permanent red F5R, pigment scarlet 3B, Bordeaux 10B; phthalocyanine blue, phthalocyanine green, sky blue Phthalocyanine-based pigments such as rhodamine lake; basic dye-based pigments such as malachite green lake and methyl violet lake; peacock blue lake; eosin lake; Acidic dye-based pigments such as yellow lake and the like. These pigments may be used alone or in combination of two or more, and are appropriately selected according to the intended color tone of the dental mill blank. Among these pigments, preferred are inorganic pigments which are excellent in heat resistance, light resistance and the like, such as titanium oxide, red iron oxide, iron oxide black and iron oxide yellow.

  The dental mill blank of the present invention includes various dental prostheses, for example, dental restorations such as inlays, onlays, veneers, crowns, bridges, etc., abutment teeth, dental posts, dentures, denture beds, It can be used for applications such as implant members (fixtures, abutments). In addition, cutting of a dental mill blank can be performed using, for example, a commercially available dental CAD / CAM system.

  In the method for producing a dental mill blank of the present invention, an inorganic filler is press-formed to obtain an inorganic filler molded body, and then a polymerizable monomer (c) and a polymerization initiator (d) are brought into contact to polymerize The paste may be cured (press-impregnation method), and the paste before polymerization may be filled into a mold, and may be pressurized and heated to polymerize and cure (paste method).

  In one embodiment, the method for producing a dental mill blank (press-impregnation method) according to the present invention comprises the steps of press-molding an inorganic filler to obtain an inorganic filler compact, the inorganic filler compact and the polymerizable monomer. A step of bringing the monomer (c) and the polymerization initiator (d) into contact with each other for polymerization and curing, and the inorganic filler and / or the inorganic filler molded product, a fluorine-containing organic group silane coupling agent (b-1) Surface-treating with. The details of each step will be described below. Moreover, the said inorganic filler and / or the said inorganic filler molded object are the silane coupling agents (b-2) which have a functional group copolymerizable with a polymerizable monomer with a silane coupling agent (b-1). May be surface treated.

  The inorganic filler in the present invention is not particularly limited as long as it can be surface-treated with the silane coupling agent (b-1), and known inorganic particles can be used, and it is known to be used as a filler for composite resin Inorganic particles (a) are preferred. As the inorganic particles (a), for example, various glasses (containing silicon dioxide (quartz, quartz glass, silica gel, etc.) or silicon as the main component and containing boron and / or aluminum together with various heavy metals), alumina, various ceramics And diatomaceous earth, kaolin, clay minerals (such as montmorillonite), activated clay, synthetic zeolite, mica, silica and the like. In addition, the inorganic filler may contain an organic-inorganic composite particle (organic-inorganic composite filler) obtained by adding a polymerizable monomer to the inorganic particle (a), polymerizing and curing it, and then grinding it. Furthermore, the inorganic filler may contain two or more types of inorganic particles (a).

  In the present invention, the inorganic filler compact can be obtained by press-molding the inorganic filler. The press molding method is not particularly limited as long as the effects of the present invention can be obtained. For example, a powder is prepared which contains the inorganic particles (a) alone or is mixed with other components such as a pigment, Among them, a method of press molding using a punch can be used. When the dental mill blank to be produced has a laminated structure, a plurality of powders prepared by changing the amount of inorganic particles (a) and other components such as pigments are prepared, filled in a mold in order, and pressed. By carrying out, it is possible to obtain a multi-layered inorganic filler compact.

  In order to produce the dental mill blank of the present invention, it is necessary to surface-treat the inorganic filler and / or the inorganic filler molded body with a silane coupling agent (b-1). Preferably, the inorganic filler is surface-treated with a silane coupling agent (b-1), and more preferably, inorganic particles (a) which have been surface-treated with a silane coupling agent (b-1) in advance Is used as an inorganic filler. By these surface treatments, it is possible to impart water repellency to the dental mill blank and to suppress a decrease in mechanical strength. Moreover, since the slipperiness of an inorganic filler can be improved by these surface treatment, when using the inorganic filler molded object obtained by press-molding an inorganic filler, the density of an inorganic filler molded object is high. Thus, a dental mill blank excellent in initial bending strength can be obtained. Further, as long as the effects of the present invention are exhibited, at least a part of the inorganic filler and / or the inorganic filler molded body may be surface-treated with the silane coupling agent (b-1).

  In order to produce the dental mill blank of the present invention, it is necessary to polymerize and harden the inorganic filler compact after contacting the polymerizable monomer. For example, a polymerizable monomer (A) may be added to an inorganic filler in which inorganic particles (a) are surface-treated with the silane coupling agent (b-1) and, if necessary, the silane coupling agent (b-2) c) and a method of bringing a polymerization initiator (d) into contact with each other for polymerization and curing.

  As the polymerizable monomer (c), known polymerizable monomers used for dental composite resins etc. may be used without any restriction, but in general, radical polymerizable monomers are suitably used. . Specific examples of the radical polymerizable monomer include esters of α-cyanoacrylic acid, (meth) acrylic acid, α-halogenated acrylic acid, crotonic acid, cinnamic acid, sorbic acid, maleic acid, itaconic acid, etc. (Meth) acrylamide, (meth) acrylamide derivatives, vinyl esters, vinyl ethers, mono-N-vinyl derivatives, styrene derivatives and the like can be mentioned. Among these, (meth) acrylic acid esters and (meth) acrylamide derivatives are preferable, and (meth) acrylic acid esters are more preferable. In the present invention, the expression "(meth) acrylic" is used in the meaning including both methacrylic and acrylic. Examples of the (meth) acrylate type polymerizable monomer and the (meth) acrylamide derivative type polymerizable monomer are shown below.

(C-1) Monofunctional (meth) acrylate and (meth) acrylamide derivative methyl (meth) acrylate, isobutyl (meth) acrylate, benzyl (meth) acrylate, lauryl (meth) acrylate, 2- (N, N-dimethyl) Amino) ethyl (meth) acrylate, 2,3-dibromopropyl (meth) acrylate, 2-hydroxyethyl (meth) acrylate, 6-hydroxyhexyl (meth) acrylate, 10-hydroxydecyl (meth) acrylate, propylene glycol mono ( Meta) acrylate, glycerol mono (meth) acrylate, erythritol mono (meth) acrylate, N-methylol (meth) acrylamide, N-hydroxyethyl (meth) acrylamide, N- (dihydroxyethyl) (meth) acrylate Llyl amide, (meth) acryloyloxy dodecyl pyridinium bromide, (meth) acryloyl oxy dodecyl pyridinium chloride, (meth) acryloyl oxy hexadecyl pyridinium chloride, (meth) acryloyl oxy decyl ammonium chloride, 10-mercaptodecyl (meth) acrylate, etc. Be

(C-2) Difunctional (meth) acrylate ethylene glycol di (meth) acrylate, triethylene glycol di (meth) acrylate, propylene glycol di (meth) acrylate, neopentyl glycol di (meth) acrylate, 1,6- Hexanediol di (meth) acrylate, 1,10-decanediol di (meth) acrylate, 2,2-bis [4- (3-acryloyloxy-2-hydroxypropoxy) phenyl] propane, 2,2-bis [4 -[3-Methacryloyloxy-2-hydroxypropoxy] phenyl] propane (generally known as Bis-GMA), 2,2-bis [4- (meth) acryloyloxyethoxyphenyl] propane, 2,2-bis [4- (meth) ) Acryloyloxypolyethoxyphenyl] propane, 1 , 2-Bis [3- (meth) acryloyloxy 2-hydroxypropoxy] ethane, pentaerythritol di (meth) acrylate, [2,2,4-trimethylhexamethylene bis (2-carbamoyloxyethyl)] dimethacrylate (common name) UDMA), 2,2,3,3,4,4-hexafluoro-1,5-pentyl di (meth) acrylate and the like.

(C-3) Trifunctional or higher (meth) acrylate trimethylolpropane tri (meth) acrylate, trimethylolethane tri (meth) acrylate, tetramethylolmethane tri (meth) acrylate, pentaerythritol tetra (meth) acrylate, di- Pentaerythritol hexa (meth) acrylate, N, N '-(2,2,4-trimethylhexamethylene) bis [2- (aminocarboxy) propane-1,3-diol] tetra (meth) acrylate, 1,7- Diacryloyloxy-2,2,6,6-tetraacryloyloxymethyl-4-oxyheptane and the like can be mentioned.

  In addition to the polymerizable monomers of (meth) acrylic acid ester type and (meth) acrylamide derivative type, cationically polymerizable oxirane compounds and oxetane compounds are also suitably used.

  Each of the polymerizable monomers (c) may be used alone or in combination of two or more. The polymerizable monomer used in the present invention is preferably in the form of liquid, but is not necessarily in the form of liquid at normal temperature, and even in the case of a solid polymerizable monomer, it is in the form of liquid It can be used by mixing and dissolving with other polymerizable monomers.

  10 Pa.s or less is preferable, as for the preferable viscosity range (25 degreeC) of a polymerizable monomer (c), 5 Pa.s or less is more preferable, and 2 Pa.s or less is still more preferable. On the other hand, when two or more types of polymerizable monomers are mixed and dissolved, or when used after solvent dilution, the viscosity of each of the polymerizable monomers (c) is the same as that of the individual polymerizable monomers. The viscosity range is not necessary, and in the state of the composition used by mixing and dissolving, the viscosity range is preferable.

  As said polymerization initiator (d), it can be used selecting from the polymerization initiators used by the general industrial industry, and the polymerization initiator currently used for the dental use is preferable, and a heat-polymerization initiator and a photopolymerization start are preferable. The agent and the chemical polymerization initiator may be used alone or in combination of two or more.

  As a heat polymerization initiator used for a polymerization initiator (d), an organic peroxide, an azo compound, etc. are mentioned.

  The organic peroxides include ketone peroxides, hydroperoxides, diacyl peroxides, dialkyl peroxides, peroxyketals, peroxy esters, peroxy dicarbonates and the like.

  Examples of the ketone peroxide include methyl ethyl ketone peroxide, methyl isobutyl ketone peroxide, methyl cyclohexanone peroxide, cyclohexanone peroxide and the like.

  Examples of the hydroperoxide include 2,5-dimethylhexane-2,5-dihydroperoxide, diisopropylbenzene hydroperoxide, cumene hydroperoxide, t-butyl hydroperoxide, 1,1,3,3-tetramethylbutyl hydroperoxide and the like. It can be mentioned.

  Examples of the diacyl peroxide include acetyl peroxide, isobutyryl peroxide, benzoyl peroxide, decanoyl peroxide, 3,5,5-trimethylhexanoyl peroxide, 2,4-dichlorobenzoyl peroxide, lauroyl peroxide and the like.

  Examples of the dialkyl peroxide include di-t-butyl peroxide, dicumyl peroxide, t-butyl cumyl peroxide, 2,5-dimethyl-2,5-di (t-butylperoxy) hexane, 1,3-bis (t -Butylperoxyisopropyl) benzene, 2,5-dimethyl-2,5-di (t-butylperoxy) -3-hexyne and the like.

  Examples of the peroxyketal include 1,1-bis (t-butylperoxy) -3,3,5-trimethylcyclohexane, 1,1-bis (t-butylperoxy) cyclohexane, 2,2-bis (t-butylperoxy) And the like) butane, 2,2-bis (t-butylperoxy) octane, 4,4-bis (t-butylperoxy) valeric acid n-butyl ester and the like.

  Examples of the peroxy ester include α-cumylperoxyneodecanoate, t-butylperoxyneodecanoate, t-butylperoxypivalate, 2,2,4-trimethylpentylperoxy-2-ethylhexanoate, t -Amyl peroxy-2-ethylhexanoate, t-butylperoxy-2-ethylhexanoate, di-t-butylperoxyisophthalate, di-t-butylperoxyhexahydroterephthalate, t-butylperoxy-3, Examples include 3,5-trimethylhexanoate, t-butyl peroxyacetate, t-butyl peroxybenzoate, t-butyl peroxymaleic acid and the like.

  Examples of the peroxydicarbonate include di-3-methoxyperoxydicarbonate, di-2-ethylhexylperoxydicarbonate, bis (4-t-butylcyclohexyl) peroxydicarbonate, diisopropylperoxydicarbonate, di-n-propylperoxydicarbonate Carbonate, di-2-ethoxyethylperoxydicarbonate, diallylperoxydicarbonate and the like can be mentioned.

  Among these organic peroxides, diacyl peroxides are preferable, and benzoyl peroxide is more preferable among them, from the comprehensive balance of safety, storage stability and radical formation ability.

  As the azo compound, 2,2'-azobis (isobutyronitrile), 2,2'-azobis (2,4-dimethylvaleronitrile), 4,4'-azobis (4-cyanovaleric acid), 1,1′-azobis (1-cyclohexanecarbonitrile), dimethyl-2,2′-azobis (isobutyrate), 2,2′-azobis (2-amidinopropane) dihydrochloride and the like.

  Examples of the photopolymerization initiator used for the polymerization initiator (d) include (bis) acyl phosphine oxides, α-diketones, coumarins and the like.

  Among the (bis) acyl phosphine oxides, as the acyl phosphine oxides, 2,4,6-trimethyl benzoyl diphenyl phosphine oxide, 2,6-dimethoxy benzoyl diphenyl phosphine oxide, 2,6-dichloro benzoyl diphenyl phosphine oxide, 2,4,6-trimethylbenzoyl methoxyphenyl phosphine oxide, 2,4,6-trimethyl benzoyl ethoxy phenyl phosphine oxide, 2,3,5,6- tetramethyl benzoyl diphenyl phosphine oxide, benzoyl di- (2, 6- dimethyl phenyl And phosphonates, and salts thereof (sodium salt, potassium salt, ammonium salt and the like) and the like. As bisacyl phosphine oxides, bis (2,6-dichlorobenzoyl) phenyl phosphine oxide, bis (2,6 dichlorobenzoyl) -2,5-dimethylphenyl phosphine oxide, bis (2,6-dichlorobenzoyl) -4 -Propylphenyl phosphine oxide, bis (2,6-dichlorobenzoyl) -1-naphthyl phosphine oxide, bis (2,6-dimethoxybenzoyl) phenyl phosphine oxide, bis (2,6-dimethoxybenzoyl) -2,4,4 -Trimethylpentyl phosphine oxide, bis (2,6-dimethoxybenzoyl) -2,5-dimethylphenyl phosphine oxide, bis (2,4,6-trimethyl benzoyl) phenyl phosphine oxide, (2,5,6-trimethyl benzoyl) -2 4,4-trimethyl pentyl phosphine oxide, and salts thereof (sodium salts, potassium salts, ammonium salts, etc.) and the like.

  Among these (bis) acyl phosphine oxides, 2,4,6-trimethyl benzoyl diphenyl phosphine oxide, 2,4,6- trimethyl benzoyl methoxy phenyl phosphine oxide, bis (2,4,6- trimethyl benzoyl) phenyl phosphine oxide And 2,4,6-trimethyl benzoyl phenyl phosphine oxide sodium salt is preferred.

  Examples of the α-diketones include diacetyl, dibenzyl, camphorquinone, 2,3-pentadione, 2,3-octadione, 9,10-phenanthrenequinone, 4,4′-oxybenzyl, acenaphthenequinone and the like. Can be mentioned. Among these, camphor quinone is preferable.

  Examples of the coumarins include 3,3′-carbonylbis (7-diethylamino) coumarin, 3- (4-methoxybenzoyl) coumarin, 3-thienoyl coumarin, 3-benzoyl-5,7-dimethoxycoumarin, 3-benzoyl -7-methoxycoumarin, 3-benzoyl-6-methoxycoumarin, 3-benzoyl-8-methoxycoumarin, 3-benzoylcoumarin, 7-methoxy-3- (p-nitrobenzoyl) coumarin, 3- (p-nitrobenzoyl) ) Coumarin, 3,5-carbonylbis (7-methoxycoumarin), 3-benzoyl-6-bromocoumarin, 3,3'-carbonylbiscoumarin, 3-benzoyl-7-dimethylaminocoumarin, 3-benzoylbenzo [f ] Coumarin, 3-carboxy coumarin, 3-carboxy-7-methoxy Marine, 3-ethoxycarbonyl-6-methoxycoumarin, 3-ethoxycarbonyl-8-methoxycoumarin, 3-acetylbenzo [f] coumarin, 3-benzoyl-6-nitrocoumarin, 3-benzoyl-7-diethylaminocoumarin, 7 -Dimethylamino-3- (4-methoxybenzoyl) coumarin, 7-diethylamino-3- (4-methoxybenzoyl) coumarin, 7-diethylamino-3- (4-diethylamino) coumarin, 7-methoxy-3 (4-methoxy) Benzoyl) coumarin, 3- (4-nitrobenzoyl) benzo [f] coumarin, 3- (4-ethoxycinnamoyl) -7-methoxycoumarin, 3- (4-dimethylaminocinnamoyl) coumarin, 3- (4- (4-dimethylaminocinnamoyl) coumarin, Diphenylaminocinnamoyl) coumarin, 3-[(3-dimeth Benzothiazol-2-ylidene) acetyl] coumarin, 3-[(1-methylnaphtho [1,2-d] thiazol-2-ylidene) acetyl] coumarin, 3,3'-carbonylbis (6-methoxycoumarin), 3 , 3'-carbonylbis (7-acetoxycoumarin), 3,3'-carbonylbis (7-dimethylaminocoumarin), 3- (2-benzothiazoyl) -7- (diethylamino) coumarin, 3- (2-) Benzothiazoyl) -7- (dibutylamino) coumarin, 3- (2-benzimidazoyl) -7- (diethylamino) coumarin, 3- (2-benzothiazoyl) -7- (dioctylamino) coumarin, 3- Acetyl-7- (dimethylamino) coumarin, 3,3'-carbonylbis (7-dibutylaminocoumarin), 3,3'-carbonyl -7-diethylaminocoumarin-7'-bis (butoxyethyl) aminocoumarin, 10- [3- [4- (dimethylamino) phenyl] -1-oxo-2-propenyl] -2,3,6,7- Tetrahydro-1,1,7,7-tetramethyl-1H, 5H, 11H- [1] benzopyrano [6,7,8-ij] quinolizine-11-one, 10- (2-benzothiazoyl) -2,3 JP-A-9-3109 such as 6,7,7-tetrahydro-1,1,7,7-tetramethyl-1H, 5H, 11H- [1] benzopyrano [6,7,8-ij] quinolizine-11-one, etc. The compound described in the gazette and Unexamined-Japanese-Patent No. 10-245525 is mentioned.

  Among the above-mentioned coumarins, 3,3'-carbonylbis (7-diethylaminocoumarin) and 3,3'-carbonylbis (7-dibutylaminocoumarin) are preferred.

  Among these photopolymerization initiators, at least one selected from the group consisting of (bis) acylphosphine oxides, α-diketones, and coumarins widely used in dental curable compositions. Is preferred.

  In addition, such a photopolymerization initiator may be able to efficiently carry out photopolymerization in a shorter time by further combining with a polymerization accelerator as necessary.

  As a polymerization accelerator suitable for the photopolymerization initiator, mainly, tertiary amines, aldehydes, compounds having a thiol group, sulfinic acid and salts thereof and the like can be mentioned.

  Examples of tertiary amines include N, N-dimethylaniline, N, N-dimethyl p-toluidine, N, N-dimethyl-m-toluidine, N, N-diethyl-p-toluidine, N, N-dimethyl 3,5-Dimethylaniline, N, N-dimethyl-3,4-dimethylaniline, N, N-dimethyl-4-ethylaniline, N, N-dimethyl-4-isopropylaniline, N, N-dimethyl-4 -T-Butylaniline, N, N-dimethyl-3,5-di-t-butylaniline, N, N-bis (2-hydroxyethyl) -3,5-dimethylaniline, N, N-bis (2- Hydroxyethyl) -p-toluidine, N, N-bis (2-hydroxyethyl) -3,4-dimethylaniline, N, N-bis (2-hydroxyethyl) -4-ethylaniline, N, N- (2-hydroxyethyl) -4-isopropylaniline, N, N-bis (2-hydroxyethyl) -4-tert-butylaniline, N, N-bis (2-hydroxyethyl) -3,5-diisopropylaniline N, N-bis (2-hydroxyethyl) -3,5-di-t-butylaniline, n-butoxyethyl 4- (N, N-dimethylamino) benzoate, 4- (N, N-dimethylamino) ) Ethyl (2-methacryloyloxy) benzoate, ethyl 4- (N, N-dimethylamino) benzoate, butyl 4- (N, N-dimethylamino) benzoate, N-methyldiethanolamine, 4- (N, N) -Dimethylamino) benzophenone, trimethylamine, triethylamine, N-methyldiethanolamine, N-ethyldiethanolamine, Nn-butyl Diethanolamine, N-lauryldiethanolamine, triethanolamine, 2- (dimethylamino) ethyl methacrylate, N-methyldiethanolamine dimethacrylate, N-ethyldiethanolamine dimethacrylate, triethanolamine monomethacrylate, triethanolamine dimethacrylate, triethanolamine trimethacrylate Methacrylate etc. are mentioned.

  Examples of aldehydes include dimethylamino benzaldehyde and terephthalaldehyde. Examples of the compound having a thiol group include 2-mercaptobenzoxazole, decanethiol, 3-mercaptopropyltrimethoxysilane, thiobenzoic acid and the like.

  Examples of sulfinic acid and salts thereof include benzenesulfinic acid, sodium benzenesulfinate, potassium benzenesulfinate, calcium benzenesulfinate, lithium benzenesulfinate, p-toluenesulfinic acid, sodium p-toluenesulfinate, p-toluene Potassium sulfinate, calcium p-toluenesulfinate, lithium p-toluenesulfinate, 2,4,6-trimethylbenzenesulfinic acid, sodium 2,4,6-trimethylbenzenesulfinate, 2,4,6-trimethylbenzenesulfin Acid potassium, calcium 2,4,6-trimethylbenzenesulfinate, lithium 2,4,6-trimethylbenzenesulfinate, 2,4,6-triethylbenzenesulfinic acid, 2,4,6-to Sodium ethylbenzenesulfinate, potassium 2,4,6-triethylbenzenesulfinate, calcium 2,4,6-triethylbenzenesulfinate, 2,4,6-triisopropylbenzenesulfinate, 2,4,6-triisopropylbenzene Sodium sulfinate, potassium 2,4,6-triisopropylbenzenesulfinate, calcium 2,4,6-triisopropylbenzenesulfinate and the like can be mentioned.

  As a chemical polymerization initiator to be used for the polymerization initiator (d), redox polymerization initiators such as organic peroxides and amines; organic peroxides, amines and sulfinic acids (and / or their salts) are preferable. When using a redox type polymerization initiator, it is necessary to take the packaging form which the oxidizing agent and the reducing agent were packaged separately, and to mix both just before using. Examples of the oxidizing agent of the redox polymerization initiator include organic peroxides. The organic peroxide is not particularly limited as an oxidizing agent of the redox type polymerization initiator, and known ones can be used. Specifically, the organic peroxide exemplified as the heat polymerization initiator may be mentioned.

  Among these organic peroxides, diacyl peroxides are preferable, and benzoyl peroxide is more preferable among them, from the comprehensive balance of safety, storage stability and radical formation ability.

  As a reducing agent for the redox polymerization initiator, usually, a tertiary aromatic amine having no electron withdrawing group on the aromatic ring is used. Examples of tertiary aromatic amines having no electron withdrawing group in the aromatic ring include N, N-dimethylaniline, N, N-dimethyl-p-toluidine, N, N-dimethyl-m-toluidine, N, N-diethyl-p-toluidine, N, N-dimethyl-3,5-dimethylaniline, N, N-dimethyl-3,4-dimethylaniline, N, N-dimethyl-4-ethylaniline, N, N-dimethyl -4-isopropylaniline, N, N-dimethyl-4-tert-butylaniline, N, N-dimethyl-3,5-di-tert-butylaniline, N, N-bis (2-hydroxyethyl) -3, 5-dimethylaniline, N, N-bis (2-hydroxyethyl) -p-toluidine, N, N-bis (2-hydroxyethyl) -3,4-dimethylaniline, N, N-bis (2-hydroxy) (Tyl) -4-ethylaniline, N, N-bis (2-hydroxyethyl) -4-isopropylaniline, N, N-bis (2-hydroxyethyl) -4-tert-butylaniline, N, N-bis ( 2-hydroxyethyl) -3,5-diisopropylaniline, N, N-bis (2-hydroxyethyl) -3,5-di-t-butylaniline.

  The chemical polymerization initiator may be used in combination with a polymerization accelerator, if necessary. The polymerization accelerator of the chemical polymerization initiator may be selected from polymerization accelerators used in general industries, and among them, polymerization accelerators used for dental use are preferred. Moreover, a polymerization accelerator is used individually by 1 type or in combination of 2 or more types suitably. Specifically, amines, sulfinic acid and salts thereof, copper compounds, tin compounds and the like can be mentioned.

  Amines used as a polymerization accelerator for chemical polymerization initiators are divided into aliphatic amines and aromatic amines having an electron withdrawing group in the aromatic ring. Examples of aliphatic amines include primary aliphatic amines such as n-butylamine, n-hexylamine and n-octylamine; and secondary aliphatic amines such as diisopropylamine, dibutylamine and N-methylethanolamine; N-methyldiethanolamine, N-ethyldiethanolamine, Nn-butyldiethanolamine, N-lauryldiethanolamine, 2- (dimethylamino) ethyl methacrylate, N-methyldiethanolamine dimethacrylate, N-ethyldiethanolamine dimethacrylate, triethanolamine monomethacrylate Tertiary fats such as triethanolamine dimethacrylate, triethanolamine trimethacrylate, triethanolamine, trimethylamine, triethylamine and tributylamine Amine, and the like. Among these, tertiary aliphatic amines are preferable from the viewpoint of curability and storage stability, and among them, N-methyldiethanolamine and triethanolamine are more preferable.

  In addition, as a tertiary aromatic amine having an electron withdrawing group on the aromatic ring used as a polymerization accelerator for a chemical polymerization initiator, for example, ethyl 4- (N, N-dimethylamino) benzoate, Methyl N, N-dimethylamino) benzoate, n-butoxyethyl 4- (N, N-dimethylamino) benzoate, 2- (methacryloyloxy) ethyl 4- (N, N-dimethylamino) benzoate, 4- Examples include (N, N-dimethylamino) benzophenone, butyl 4- (N, N-dimethylamino) benzoate and the like. Among these, N, N-bis (2-hydroxyethyl) -p-toluidine, ethyl 4- (N, N-dimethylamino) benzoate, 4- (N, N) from the viewpoint of being able to impart excellent curability. At least one selected from the group consisting of n-butoxyethyl benzoate and 4- (N, N-dimethylamino) benzophenone.

  As the sulfinic acid and its salt used as the polymerization accelerator, those exemplified as the polymerization accelerator of the above-mentioned photopolymerization initiator can be mentioned, and sodium benzenesulfinate, sodium p-toluenesulfinate, 2,4,6- Sodium triisopropylbenzenesulfinate is preferred.

  As a copper compound used as a polymerization accelerator, for example, acetylacetone copper, cupric acetate, copper oleate, cupric chloride, cupric bromide and the like are suitably used.

  Examples of tin compounds used as a polymerization accelerator include di-n-butyltin dimaleate, di-n-octyltin dimaleate, di-n-octyltin dilaurate, di-n-butyltin dilaurate and the like. Particularly preferred tin compounds are di-n-octyltin dilaurate and di-n-butyltin dilaurate.

  Among these, it is preferable to use a photopolymerization initiator and a heat polymerization initiator in combination, and a combination of (bis) acyl phosphine oxides and diacyl peroxide is more preferable.

  The content of the polymerization initiator (d) is not particularly limited, but from the viewpoint of the curability of the composition to be obtained, etc., 0.001 to 30 parts by mass with respect to 100 parts by mass of the polymerizable monomer (c) It is preferred to use. When the content of the polymerization initiator (d) is 0.001 parts by mass or more based on 100 parts by mass of the polymerizable monomer (c), the polymerization may proceed sufficiently to cause a decrease in mechanical strength. It is more preferably 0.05 parts by mass or more, and still more preferably 0.1 parts by mass or more. On the other hand, when the content of the polymerization initiator (d) is 30 parts by mass or less with respect to 100 parts by mass of the polymerizable monomer (c), sufficient even when the polymerization performance of the polymerization initiator itself is low Mechanical strength is obtained, and furthermore, there is no possibility of causing precipitation from the composition, and it is more preferably 20 parts by mass or less.

  In another embodiment, the method for producing a dental mill blank (paste method) according to the present invention includes the step of surface-treating an inorganic filler with a silane coupling agent (b-1) having a fluorine-containing organic group, the inorganic The steps of kneading the filler and the polymerizable monomer (c) to obtain a paste, and filling the above-mentioned paste into a mold, pressing and compressing, and then polymerizing and curing it are included. The inorganic filler, the silane coupling agent (b-1), and the polymerizable monomer (c) are the same as in the above-described embodiment (press-impregnation method). Also, the paste contains the above-mentioned polymerization initiator (d). The polymerization initiator (d) and the polymerization accelerator are also the same as in the embodiment (press-impregnation method) described above. In the production method, the inorganic filler is surface-treated with a silane coupling agent (b-1) and a silane coupling agent (b-2) having a functional group copolymerizable with the polymerizable monomer. May be

  From the viewpoint of increasing the proportion of the inorganic filler in the dental mill blank, the press-impregnation method is more preferable as a method for producing the dental mill blank than the paste method. In addition, the inorganic filler surface-treated with the silane coupling agent (b-1) in the press-impregnation method has a feature that the friction with the mold is reduced when a dry press is selected as press molding (slip property In the same load (surface pressure), the density of the resulting inorganic filler compact and the initial bending strength of the mill blank are improved.

  EXAMPLES The present invention will be specifically described below by way of Examples, but the present invention is not limited by these Examples.

[Production example of polymerizable monomer-containing composition (C-1)]
Benzoyl peroxide which is a thermal polymerization initiator in 70 parts by mass of [2,2,4-trimethylhexamethylene bis (2-carbamoyloxyethyl)] dimethacrylate (UDMA) and 30 parts by mass of triethylene glycol dimethacrylate (TEGDMA) The polymerizable monomer-containing composition (C-1) was prepared by dissolving parts by mass.

[Production Example of Polymerizable Monomer-Containing Composition (C-2)]
100 parts by mass of [2,2,4-trimethylhexamethylene bis (2-carbamoyloxyethyl)] dimethacrylate (UDMA) with 1 part by mass of 1,1,3,3-tetramethylbutyl hydroperoxide as a heat polymerization initiator The polymerizable monomer-containing composition (C-2) was prepared by dissolving parts.

[Production Example of Inorganic Particles (A-1)]
100 g of commercially available inorganic ultrafine particles (manufactured by Nippon Aerosil Co., Ltd., Aerosil OX-50, average primary particle diameter 40 nm, BET specific surface area 50 m ² / g) are dispersed in 500 mL of water, 1,1,1-trifluoro-3- 2.0 g of [dimethoxy (methyl) silyl] propane were added and stirred at room temperature (about 25 ° C.) for 2 hours. Thereafter, 3.5 g of γ-methacryloyloxypropyltrimethoxysilane (hereinafter, may be referred to as γ-MPS), and a trace amount of pigment (manufactured by Wako Pure Chemical Industries, Ltd., titanium oxide (Nippon Bureau), manufactured by Toda Kogyo Co., Ltd. , Iron oxide black, iron oxide red, iron oxide yellow) were added, and the mixture was further stirred at room temperature for 2 hours. After spray-drying using a spray drier (model B290 manufactured by Buchi), drying was carried out at 90 ° C. for 3 hours to obtain surface-treated powdery inorganic particles (A-1).

[Production Example of Inorganic Particles (A-2), (A-3)]
100 g of commercially available inorganic ultrafine particles (manufactured by Nippon Aerosil Co., Ltd., Aerosil OX-50, average primary particle diameter 40 nm, BET specific surface area 50 m ² / g) are dispersed in 500 mL of water, and inorganic particles (A-2) In the inorganic particles (A-3), 3.5 g of 1H, 1H, 2H, 2H-tridecafluoro-n-octyl) silane and 3.5 g of trimethoxy (pentafluorophenyl) silane were added, and each of them was added to room temperature (approximately 25 Stir for 2 hours at. Thereafter, in both production examples, 3.5 g of γ-MPS and a trace amount of pigment were added and the mixture was further stirred at room temperature for 2 hours. After spray-drying using a spray dryer (Buchi B290) and drying at 90 ° C. for 3 hours, surface-treated powdery inorganic particles (A-2) and (A-3) were obtained. .

[Production Example of Inorganic Particles (A-4)]
100 g of commercially available inorganic ultrafine particles (Aerosil OX-50, average primary particle diameter 40 nm, BET specific surface area 50 m ² / g, manufactured by Nippon Aerosil Co., Ltd.) are dispersed in 500 mL of water, and 7.0 g of γ-MPS, a trace amount of pigment is added The mixture was further stirred at room temperature (about 25 ° C.) for 2 hours. After spray-drying using a spray drier (model B290 manufactured by Buchi), the resultant was dried at 90 ° C. for 3 hours to obtain surface-treated powdery inorganic particles (A-4).

[Production Example of Inorganic Particles (A-5) to (A-8)]
100 g of a commercially available inorganic ultrafine particle (manufactured by Sakai Chemical Industry Co., Ltd., Sciqas, average primary particle diameter 100 nm, BET specific surface area 21.5 m ² / g) is dispersed in 500 mL of water, and the above inorganic particles (A-1) to (A) Inorganic particles (A-5) to (A-8) were obtained by surface treatment in the same manner as -4).

[Production Example of Inorganic Particles (A-9) to (A-12)]
100 g of a commercially available barium boroaluminosilicate glass powder (GM27884 manufactured by Schott Co., NF 180, average particle diameter 180 nm, crushed) is dispersed in 500 mL of water, and each of them is the same as the above inorganic particles (A-1) to (A-4). Inorganic particles (A-9) to (A-12) were obtained by surface treatment by a method.

[Production Example of Inorganic Particles (A-13), (A-14)]
100 g of commercially available barium boroaluminosilicate glass powder (GM27884 manufactured by Schott, UF 2.0, average particle size 2.0 μm, crushed) is dispersed in 500 mL of water, and the above inorganic particles (A-1) and (A-4) are dispersed. The inorganic particles (A-13) and (A-14) were obtained by surface treatment in the same manner as in the above.

  The inorganic particles (A-1) to (A-14) obtained in each of the above production examples are summarized in Table 1.

[Examples 1-1, 1-2]
30.0 g of the surface-treated powdery inorganic particles (A-1) was placed on the lower punch rod of a press die having a rectangular hole of 35 mm × 25 mm. After the inorganic particles were smoothed by tapping, the upper punch rod was set on top, and uniaxial pressing (surface pressure 68.6 MPa (load 60.0 kN), time 1 minute) was performed using a press. The upper punch bar and the lower punch bar were removed from the mold, and the inorganic filler compact (the press compact) in which the powder of the inorganic particles was aggregated was taken out. The size of the pressed body was a prism of 35 mm × 25 mm × 29.8 mm, and the density of the formed body was 1.15 g / cm ³ . The press-formed product is placed inside a polyethylene bag, and in the case of Example 1-1, the polymerizable monomer-containing composition (C-1), in the case of Example 1-2, The polymerizable monomer-containing composition is introduced into the press-molded product by introducing the polymerizable monomer-containing composition (C-2) into the inside of the bag and reducing the pressure inside the bag (0.001 kPa or less). (C-1) or (C-2) was impregnated. Then, after heating these 2 types of press-formed products impregnated with each polymerizable monomer-containing composition at 55 ° C. for 18 hours using a hot air drier, the resulting mixture is further heated at 110 ° C. for 3 hours, Each obtained a polymerizable cured product.

[Example 2-1, 2-2]
Using 30.0 g of the surface-treated powdery inorganic particles (A-2), a press-molded product having a density of 1.18 g / cm ³ is produced with a prismatic shape of 35 mm × 25 mm × 29.1 mm. A polymerizable cured product was obtained in the same manner as in Examples 1-1 and 1-2, respectively, except for the above.

[Examples 3-1 and 3-2]
Using 30.0 g of surface-treated powdery inorganic particles (A-3), a press-molded product having a density of 1.10 g / cm ³ is produced with a prismatic shape of 35 mm × 25 mm × 31.2 mm. A polymerizable cured product was obtained in the same manner as in Examples 1-1 and 1-2, respectively, except for the above.

Comparative Examples 1-1 and 1-2
Using 30.0 g of surface-treated powdery inorganic particles (A-4), a press-molded product having a density of 1.05 g / cm ³ is produced with a prismatic shape of 35 mm × 25 mm × 32.7 mm. A polymerizable cured product was obtained in the same manner as in Examples 1-1 and 1-2, respectively, except for the above.

Examples 4-1 and 4-2
Using 30.0 g of surface-treated powdery inorganic particles (A-5), a press-molded product having a density of 1.18 g / cm ³ is produced with a prismatic shape of 35 mm × 25 mm × 29.1 mm. A polymerizable cured product was obtained in the same manner as in Examples 1-1 and 1-2, respectively, except for the above.

[Examples 5-1 and 5-2]
Using 30.0 g of surface-treated powdery inorganic particles (A-6), a press-molded product having a density of 1.20 g / cm ³ is produced with a prismatic shape of 35 mm × 25 mm × 28.6 mm. A polymerizable cured product was obtained in the same manner as in Examples 1-1 and 1-2, respectively, except for the above.

[Examples 6-1, 6-2]
Using 30.0 g of surface-treated powdery inorganic particles (A-7), a press-molded product having a density of 1.15 g / cm ³ is produced with a prismatic shape of 35 mm × 25 mm × 29.8 mm. A polymerizable cured product was obtained in the same manner as in Examples 1-1 and 1-2, respectively, except for the above.

[Comparative example 2-1, 2-2]
Using 30.0 g of surface-treated powdery inorganic particles (A-8), a press-molded product having a density of 1.06 g / cm ³ is produced in a prismatic shape of 35 mm × 25 mm × 32.3 mm. A polymerizable cured product was obtained in the same manner as in Examples 1-1 and 1-2, respectively, except for the above.

[Examples 7-1 and 7-2]
Using 30.0 g of surface-treated powdery inorganic particles (A-9), a press-molded product having a density of 1.35 g / cm ³ is produced with a prismatic shape of 35 mm × 25 mm × 25.4 mm. A polymerizable cured product was obtained in the same manner as in Examples 1-1 and 1-2, respectively, except for the above.

[Examples 8-1 and 8-2]
Using 30.0 g of surface-treated powdery inorganic particles (A-10), a press-molded product having a density of 1.39 g / cm ³ is produced in a prismatic shape of 35 mm × 25 mm × 24.7 mm. A polymerizable cured product was obtained in the same manner as in Examples 1-1 and 1-2, respectively, except for the above.

[Examples 9-1 and 9-2]
Using 30.0 g of surface-treated powdery inorganic particles (A-11), a press-molded product having a density of 1.32 g / cm ³ is produced in a prismatic shape of 35 mm × 25 mm × 26.0 mm. A polymerizable cured product was obtained in the same manner as in Examples 1-1 and 1-2, respectively, except for the above.

Comparative Examples 3-1 and 3-2
Using 30.0 g of surface-treated powdery inorganic particles (A-12), a press-molded product having a density of 1.27 g / cm ³ is produced in a prismatic shape of 35 mm × 25 mm × 27.0 mm. A polymerizable cured product was obtained in the same manner as in Examples 1-1 and 1-2, respectively, except for the above.

[Examples 10-1 and 10-2]
Using 30.0 g of surface-treated powdery inorganic particles (A-13), a press-molded product having a density of 1.55 g / cm ³ is produced with a prismatic shape of 35 mm × 25 mm × 22.1 mm. A polymerizable cured product was obtained in the same manner as in Examples 1-1 and 1-2, respectively, except for the above.

Comparative Examples 4-1 and 4-2
Using 30.0 g of surface-treated powdery inorganic particles (A-14), a press-molded product having a density of 1.45 g / cm ³ is produced in a prismatic shape of 35 mm × 25 mm × 23.6 mm. A polymerizable cured product was obtained in the same manner as in Examples 1-1 and 1-2, respectively, except for the above.

[Test example]
Measurement of Contact Angle The polymerizable cured product prepared in each Example and Comparative Example is cut using a diamond cutter (Isomet 1000, manufactured by Buehler), and a test piece of 12.00 mm × 12.00 mm × 1.40 mm in size And finished with 1.20 mm thickness using three sheets of water resistant abrasive paper (# 1000, # 2000, # 3000). Using a contact angle meter (DMo-1101, Kyowa Interface Chemical Co., Ltd.), 1 μL of water droplets were dropped on each of the test pieces, and the contact angle was measured.

Three-Point Bending Strength Measurement The three-point bending strength of the polymerizable cured product prepared in each example and comparative example was measured by the following method. That is, a test piece (1.2 mm × 4.0 mm × 14.0 mm) was produced from the manufactured dental mill blank using a diamond cutter. Later, it finished to thickness 1.20 mm using two sheets of water resistant abrasive paper (# 1000, # 2000). These test pieces were prepared in 20 pieces per sample, and 10 pieces were immersed in water for one week in a constant temperature of 37 ° C. without immersion in water, and used for measurement. These are set in a universal testing machine (manufactured by Shimadzu Corporation), and each test is conducted according to the three-point bending test method (JDMAS 245: 2017 applies mutatis mutandis) under the conditions of cross head speed 1 mm / min and support point distance 12 mm. The three-point bending strength of the piece was measured. The decrease rate of 3-point bending strength is calculated according to the following formula, assuming that the product not immersed in water is "initial bending strength" and the product immersed in water in a constant temperature of 37 ° C for 1 week as "bending strength after water immersion". did.
Decrease rate of 3-point bending strength (%) = {(bending strength after water immersion)-(initial bending strength) / (initial bending strength) x 100

  The measurement result of each physical property measured by the method as described in a test example was put together in Table 2 about the polymeric cured material obtained by each above Example and the comparative example.

  As shown in Table 2, the polymerizable cured product of each example corresponding to the dental mill blank of the present invention does not include the step of treating with a silane coupling agent (b-1) having a fluorine-containing organic group. As compared with the polymerizable cured products of the respective comparative examples manufactured in the above, it can be seen that the reduction rate of the three-point bending strength after immersion in water is smaller and the water resistance is very excellent. In addition, although the polymerizable cured product of each example had a higher density of the press-formed body and higher initial bending strength as compared with each of the comparative examples, the result was that the silane coupling agent (b-1) It is inferred that the slipperiness of the inorganic filler was improved by surface treatment with

  ADVANTAGE OF THE INVENTION According to this invention, the dental mill blank which is excellent in water resistance which can suppress the fall of mechanical strength in the environment where water exists like an intraoral area, and its simple manufacturing method can be provided. Further, according to the present invention, it is possible to obtain a dental prosthesis which is excellent in mechanical strength even in the presence of water as in the oral cavity. Furthermore, according to the present invention, the slipperiness of the inorganic filler is improved, and a dental mill blank excellent in initial bending strength can be obtained.

Claims (8)

  A dental mill blank having a reduction rate of three-point bending strength of 20% or less when immersed in water at 37 ° C. for one week.   The dental mill blank according to claim 1, wherein the contact angle to water is 60 ° or more.   The dental mill blank according to claim 1, further comprising an inorganic filler surface-treated with a silane coupling agent (b-1) having a fluorine-containing organic group. The silane coupling agent (b-1) is represented by the following general formula (I)
R ¹ _n -SiX _4-n (I)
[Wherein, R ¹ is a C ¹ to C 12 perfluorohydrocarbon group or a C ¹ to C 12 hydrocarbon group having a C ¹ to C 6 perfluoroalkyl group, and X is a C ¹ to C ¹ carbon atom] 4 represents an alkoxy group, an acetoxy group, a hydroxyl group, a halogen atom, or a hydrogen atom, and n is an integer of 0 to 3, provided that R ¹ and X each may be the same or different . ]
The dental mill blank according to claim 3, which is a silane coupling agent represented by   The inorganic filler according to claim 3 or 4, wherein the inorganic filler is an inorganic filler which is further surface-treated with a silane coupling agent (b-2) having a functional group copolymerizable with the polymerizable monomer. Dental mill blanks. A step of press-forming the inorganic filler to obtain an inorganic filler compact,
A step of bringing the inorganic filler molding into contact with the polymerizable monomer (c) and the polymerization initiator (d) for polymerization and curing, and the inorganic filler and / or the inorganic filler molding, Including the step of surface treatment with a silane coupling agent (b-1) having a group
The manufacturing method of dental mill blanks. Treating the inorganic filler with a silane coupling agent (b-1) having a fluorine-containing organic group,
Kneading the inorganic filler and the polymerizable monomer (c) to obtain a paste, and filling the paste into a mold, pressing and compressing, and then polymerizing and curing.
The manufacturing method of dental mill blanks. The silane coupling agent (b-1) is represented by the following general formula (I)
R ¹ _n -SiX _4-n (I)
[Wherein, R ¹ is a C ¹ to C 12 perfluorohydrocarbon group or a C ¹ to C 12 hydrocarbon group having a C ¹ to C 6 perfluoroalkyl group, and X is a C ¹ to C ¹ carbon atom] 4 represents an alkoxy group, an acetoxy group, a hydroxyl group, a halogen atom, or a hydrogen atom, and n is an integer of 0 to 3, provided that R ¹ and X each may be the same or different . ]
The manufacturing method of the dental mill blank of Claim 6 or 7 which is a silane coupling agent represented by these.