JP2016210710A - Block for cutting work - Google Patents

Abstract

There is provided a block for cutting which is free from cracks and excellent in machinability at the time of cutting, but has excellent impact resistance, wear resistance and aesthetics when used in the oral cavity. The present invention relates to a (meth) acrylic acid ester polymer (a), a monofunctional (meth) acrylic acid ester polymerizable monomer (b-1), and a polyfunctional (meth) acrylic. A polymerizable monomer (b) containing an acid ester polymerizable monomer (b-2) and a polymerization initiator (c), and containing the (meth) acrylic acid ester polymer (a) The amount is 1 to 50 parts by weight with respect to 100 parts by weight of the polymerizable monomer (b), and the (meth) acrylate polymer (a) is the polymerizable monomer (b). It is a block for cutting process obtained by hardening | curing the composition melt | dissolved in this. [Selection figure] None

Description

  TECHNICAL FIELD The present invention relates to a dental prosthesis used for a denture base and the like in dental treatment, and relates to a block used by cutting with a CAD / CAM system.

  As a material used to make a prosthesis such as a denture base for dentistry, a composition containing a (meth) acrylate-based polymerizable monomer, a polymerization initiator, an inorganic filler, etc. is cured. These materials are widely used.

  Conventionally, these denture bases are generally manufactured by taking a mold in the oral cavity of a patient, filling a resin or a polymerizable composition in accordance with the mold, pouring and then curing the mold. However, this method requires not only a large number of manufacturing steps, but also requires a very high dimensional accuracy of several μm for denture bases, requiring not only a great deal of time but also the skill of an engineer.

  In recent years, as a method for stably supplying a denture base of a certain quality in a short time, the denture base is designed on the screen using a computer, and the denture base is manufactured by cutting from a resin material or a ceramic block. CAD / CAM systems are attracting attention, and denture base design and production systems such as the SEREC system are widely used.

  As a material for dental cutting for such a CAD / CAM system, for example, Patent Document 1 includes an acrylic material containing 20 to 70% by weight of an inorganic filler having an average particle size of 0.01 to 0.04 μm. A resin material for cutting which is made of a resin polymer and has excellent mechanical performance is described. Patent Document 2 describes a cutting resin material containing a specific proportion of polyethylene glycol dimethacrylate having a molecular weight of 300 or more and 780 or less, in which generation of cracks is suppressed during curing. Furthermore, in Patent Document 3, a methyl methacrylate polymer powder having a weight ratio of about 2 to 3 times is mixed with a monomer comprising a mixture of methyl methacrylate and ethylene glycol dimethacrylate, and the powder is dissolved in the monomer. An example of a denture base preparation block produced by press-molding a rod-like material simply swollen in a monomer without being described is described.

JP-A-10-323353 JP 2012-214398 A International Publication 2011/136163

  One of the advantages of the CAD / CAM system is that it can be manufactured in a short time and at a low cost. Therefore, the cutting material requires a good machinability. Although it describes that it is excellent in machinability, the Example which demonstrates it is not described. Patent Documents 2 and 3 do not mention machinability.

  Therefore, the present invention has an object to provide a block for cutting which has no cracks and is excellent in machinability at the time of cutting, but has excellent impact resistance, wear resistance and aesthetics when used in the oral cavity. And

  The present invention relates to a (meth) acrylic acid ester polymer (a), a monofunctional (meth) acrylic acid ester polymerizable monomer (b-1), and a polyfunctional (meth) acrylic acid ester polymerization. The polymerizable monomer (b) containing the polymerizable monomer (b-2) and the polymerization initiator (c) are contained, and the content of the (meth) acrylic acid ester polymer (a) is the polymerization 1 to 50 parts by weight with respect to 100 parts by weight of the polymerizable monomer (b), and the (meth) acrylic acid ester polymer (a) is dissolved in the polymerizable monomer (b). There is provided a cutting block obtained by curing a composition.

  In the cutting block, the glass transition temperature of the homopolymer of the monofunctional (meth) acrylic acid ester polymerizable monomer (b-1) is preferably 60 ° C. or higher.

  In the cutting block, the polyfunctional (meth) acrylic acid ester polymerizable monomer (b-2) preferably contains a (meth) acrylic acid ester polymerizable monomer having a urethane bond. .

  The cutting block preferably contains an inorganic filler (d) having an average particle size of 0.001 to 0.10 μm.

In the cutting block, it is preferable that a volume is 15cm ³ or more 500 cm ³ or less.

  The cutting block is preferably for a denture base.

  Moreover, this invention provides the dental prosthesis produced from the said block for cutting.

  Furthermore, this invention provides the denture base obtained by cutting the said block for cutting.

  The block for cutting according to the present invention is free from cracks and has excellent cutting properties at the time of cutting, but also has excellent impact resistance, wear resistance, and aesthetics when used in the oral cavity. Further, the cutting block of the present invention is excellent in mechanical strength in addition to the above characteristics. In particular, the denture base is large, and the cutting ability and impact resistance are strongly required. Therefore, the cutting block of the present invention is useful.

  The cutting block of the present invention comprises a (meth) acrylic acid ester polymer (a), a monofunctional (meth) acrylic acid ester polymerizable monomer (b-1), and a polyfunctional (meth). A polymerizable monomer (b) containing an acrylate-based polymerizable monomer (b-2) and a polymerization initiator (c), the (meth) acrylate-based polymer (a) The content is 1 to 50 parts by weight with respect to 100 parts by weight of the polymerizable monomer (b), and the (meth) acrylic acid ester polymer (a) is the polymerizable monomer (b). It is obtained by curing the composition dissolved in (1). In this specification, (meth) acryl is a general term for methacryl and acryl, and the same applies to similar expressions.

(Meth) acrylic acid ester polymer (a)
The (meth) acrylic acid ester-based polymer (a) is used in the cutting block of the present invention to impart cutting workability and to suppress the occurrence of cracks. The (meth) acrylic acid ester polymer (a) is a polymer in which no (meth) acrylic group remains, and is usually a (meth) acrylic polymer or copolymer classified as a plastic.

  The higher the glass transition temperature (Tg) of the (meth) acrylic acid ester polymer (a), the more the cutting performance of the cutting block of the present invention is not impaired. For this reason, the Tg of the (meth) acrylic acid ester polymer (a) is preferably 60 ° C. or higher, more preferably 80 ° C. or higher.

  The monomer (meth) acrylate ester constituting the (meth) acrylate polymer (a) is preferably a (meth) acrylate ester having a homopolymer Tg of 60 ° C. or higher.

  The (meth) acrylic acid ester polymer (a) monomer (meth) acrylic acid ester has a homopolymer Tg of 60 ° C. or higher. , Branched, radial, or a combination of two or more of them. Among these, linear or branched homopolymers are preferably used because of the ease of production of the (meth) acrylic acid ester polymer (a).

  Examples of the (meth) acrylic acid ester having a homopolymer Tg of 60 ° C. or higher include, for example, methyl (meth) acrylate, ethyl (meth) acrylate, tert-butyl (meth) acrylate, and cyclohexyl (meth) acrylate. , Adamantyl (meth) acrylate, 2-methyl-2-adamantyl (meth) acrylate, 2-ethyl-2-adamantyl (meth) acrylate, isobornyl (meth) acrylate, phenyl (meth) acrylate, etc. It is done. Among these, from the fact that the resulting block for cutting work has good impact resistance and availability, methyl methacrylate (MMA), tert-butyl methacrylate (TBM), adamantyl methacrylate, isobornyl methacrylate (IBM) is preferred, methyl methacrylate and isobornyl methacrylate are more preferred, and methyl methacrylate is most preferred.

  The (meth) acrylic acid ester polymer (a) is preferably a non-crosslinked (meth) acrylic acid ester polymer (a) from the viewpoint of excellent solubility in the polymerizable monomer (b). "Non-crosslinked" means that the polymers are not crosslinked with each other and dissolved in an organic solvent such as (meth) acrylic acid ester or chloroform, methylene chloride, ethanol, isopropanol, acetone, ethyl acetate. Alternatively, it can be confirmed that it is not crosslinked by melting when heated to 200 ° C. to 300 ° C.

  The (meth) acrylic acid ester polymer (a) may contain (meth) acrylic acid ester polymerizable monomers other than those described above as long as the effects of the present invention are not impaired. Monomer units may be included. Other monomers include, for example, vinyl monomers having a carboxyl group such as (meth) acrylic acid ester, (meth) acrylic acid, maleic acid, maleic anhydride, etc. whose Tg of the homopolymer is lower than 60 ° C .; (meth) acrylamide Aromatic vinyl monomers such as styrene, α-methylstyrene and p-methylstyrene; conjugated diene monomers such as butadiene and isoprene; and olefin monomers such as ethylene and propylene.

  The weight average molecular weight (Mw) of the (meth) acrylic acid ester polymer (a) is from 10,000 to 2,000,000 from the viewpoint of the solubility in the polymerizable monomer (b) and the impact resistance of the resulting block for machining. Is preferably in the range of 20000 to 1000000, more preferably in the range of 30000 to 500000. In addition, a weight average molecular weight here means the weight average molecular weight of polystyrene conversion calculated | required by gel permeation chromatography (GPC).

  The method for producing the (meth) acrylic acid ester polymer (a) is not particularly limited as long as a polymer satisfying the conditions of the present invention concerning the chemical structure is obtained, and is a method according to a known method. Can be adopted. Moreover, a commercial item can be used for the (meth) acrylic acid ester polymer (a). Examples of commercially available products include Hyperl (registered trademark) series manufactured by Negami Kogyo Co., Ltd., M-4003 (Tg: 105 ° C), M-4006 (Tg: 105 ° C), M-4501 (Tg: 84 ° C). ), M-5000 (Tg: 65 ° C.), M-5001 (Tg: 65 ° C.) and the like.

  The content of the (meth) acrylic acid ester polymer (a) is 1 to 50 parts by weight with respect to 100 parts by weight of the total amount of the polymerizable monomer (b) described later, and the generation of cracks can be further suppressed. From the viewpoint that the (meth) acrylic acid ester polymer (a) can be satisfactorily dissolved in the polymerizable monomer (b), 2.5 to 40 parts by weight is preferable, and 5 to 30 parts by weight is more preferable.

Polymerizable monomer (b)
As the polymerizable monomer (b), a monofunctional (meth) acrylic acid ester polymerizable monomer (b-1) having one (meth) acryloyl group (hereinafter referred to as “monofunctional (meth)”. Acrylic ester-based polymerizable monomer (b-1) ”) and polyfunctional (meth) acrylic ester-based polymerizable monomer (b-2) having a plurality of (meth) acryloyl groups (hereinafter, "Multifunctional (meth) acrylic acid ester-based polymerizable monomer (b-2)").

  The monofunctional (meth) acrylic acid ester polymerizable monomer (b-1) is a glass transition temperature of a homopolymer of the monofunctional (meth) acrylic acid ester polymerizable monomer (b-1) ( The higher the Tg), the better the machinability and impact resistance of the cutting block of the present invention. For this reason, the Tg of the homopolymer of the monofunctional (meth) acrylic acid ester-based polymerizable monomer (b-1) is preferably 60 ° C. or higher, and more preferably 80 ° C.

  In the monofunctional (meth) acrylic acid ester-based polymerizable monomer (b-1), for example, in the (meth) acrylic acid ester-based polymer (a), the Tg of the homopolymer is 60 ° C. or more ( The same as those mentioned as the (meth) acrylic acid ester.

  From the viewpoint of impact resistance and transparency, the content of the monofunctional (meth) acrylic acid ester-based polymerizable monomer (b-1) is 100% by weight based on the total amount of the polymerizable monomer (b). 45 to 99% by weight, preferably 55 to 98% by weight, and more preferably 60 to 95% by weight.

  Moreover, the block for cutting according to the present invention may contain a fluorine-containing methacrylic ester polymerizable monomer as the polymerizable monomer (b-1) for the purpose of adjusting coloring resistance to a pigment or the like. . Examples of such fluorine-containing methacrylate ester polymerizable monomers include 2,2,2-trifluoroethyl methacrylate, 2,2,3,3,3-pentafluoropropyl methacrylate, 2- (perfluoro Butyl) ethyl methacrylate, 3- (perfluorobutyl) -2-hydroxypropyl methacrylate, 2- (perfluorohexyl) ethyl methacrylate, 3-perfluorohexyl-2-hydroxypropyl methacrylate, 3- (perfluoro-3-methylbutyl)- 2-hydroxypropyl methacrylate, 1H, 1H, 3H-tetrafluoropropyl methacrylate, 1H, 1H, 5H-octafluoropentyl methacrylate, 1H, 1H, 7H-dodecafluoroheptyl methacrylate, 1H-1- (tri Ruoromechiru) trifluoroethyl methacrylate, and IH, IH, 3H-hexafluorobutyl methacrylate. Among these, 2- (perfluorobutyl) ethyl methacrylate, 2- (perfluorohexyl) ethyl methacrylate, 1H, 1H, 5H-octafluoropentyl methacrylate, 1H, 1H, 7H-dodeca are excellent in coloration resistance. Fluoroheptyl methacrylate, 1H-1- (trifluoromethyl) trifluoroethyl methacrylate, 1H, 1H, 3H-hexafluorobutyl methacrylate are preferred, 1H, 1H, 5H-octafluoropentyl methacrylate, 1H, 1H, 7H-dodecafluoro More preferred is heptyl methacrylate.

  The content of the fluorine-containing methacrylate ester polymerizable monomer is not particularly limited, but from the viewpoint of coloring resistance and machinability, 10 to 90% by weight is preferable in the polymerizable monomer (b-1), 20 to 70% by weight is more preferable, and 30 to 50% by weight is more preferable.

  Examples of the polyfunctional (meth) acrylic acid ester-based polymerizable monomer (b-2) include an aromatic compound-based bifunctional (meth) acrylic acid ester-based polymerizable monomer and an aliphatic compound-based monomer. Examples thereof include a functional (meth) acrylic acid ester polymerizable monomer and a trifunctional or higher (meth) acrylic acid ester polymerizable monomer.

  Examples of the aromatic compound-based bifunctional (meth) acrylic acid ester-based polymerizable monomer include 2,2-bis ((meth) acryloyloxyphenyl) propane, 2,2-bis [4- (3 -Acryloyloxy-2-hydroxypropoxy) phenyl] propane, 2,2-bis [4- (3-methacryloyloxy-2-hydroxypropoxy) phenyl] propane (commonly referred to as “Bis-GMA”), 2,2-bis ( 4- (meth) acryloyloxyethoxyphenyl) propane, 2,2-bis (4- (meth) acryloyloxypolyethoxyphenyl) propane, 2,2-bis (4- (meth) acryloyloxydiethoxyphenyl) propane, 2,2-bis (4- (meth) acryloyloxytetraethoxyphenyl) propane, 2,2-bis (4 (Meth) acryloyloxypentaethoxyphenyl) propane, 2,2-bis (4- (meth) acryloyloxydipropoxyphenyl) propane, 2- (4- (meth) acryloyloxydiethoxyphenyl) -2- (4- (Meth) acryloyloxyethoxyphenyl) propane, 2- (4- (meth) acryloyloxydiethoxyphenyl) -2- (4- (meth) acryloyloxyditriethoxyphenyl) propane, 2- (4- (meth) acryloyl Oxydipropoxyphenyl) -2- (4- (meth) acryloyloxytriethoxyphenyl) propane, 2,2-bis (4- (meth) acryloyloxypropoxyphenyl) propane, 2,2-bis (4- (meta ) Acryloyloxyisopropoxyphenyl) propane And 1,4-bis (2- (meth) acryloyloxyethyl) pyromellitate, and the like. These may be used alone or in combination of two or more. Among these, 2,2-bis (4- (meth) acryloyloxypoly) is good in that it is miscible with the (meth) acrylic acid ester polymer (a) and has excellent machinability of the block for machining. Ethoxyphenyl) propane is preferred.

  Examples of aliphatic compound-based bifunctional (meth) acrylic acid ester-based polymerizable monomers include glycerol di (meth) acrylate, ethylene glycol di (meth) acrylate, diethylene glycol di (meth) acrylate, and triethylene glycol. Di (meth) acrylate, propylene glycol di (meth) acrylate, butylene glycol di (meth) acrylate, neopentyl glycol di (meth) acrylate, polyethylene glycol di (meth) acrylate, 1,3-butanediol di (meth) acrylate 1,4-butanediol di (meth) acrylate, 1,6-hexanediol di (meth) acrylate, 2-ethyl-1,6-hexanediol di (meth) acrylate, 1,9-nonanediol di (meth) Acry 1,10-decanediol di (meth) acrylate, 1,2-bis (3-methacryloyloxy-2-hydroxypropoxy) ethane, and 2,2,4-trimethylhexamethylenebis (2-carbamoyloxyethyl) ) Dimethacrylate (commonly known as “UDMA”). Among these, glycerol di (meta) is preferred because of its good miscibility with the (meth) acrylic acid ester polymer (a) and the excellent machinability, impact resistance and wear resistance of the resulting machining block. ) Acrylate, triethylene glycol di (meth) acrylate, 1,6-hexanediol di (meth) acrylate and 2,2,4-trimethylhexamethylenebis (2-carbamoyloxyethyl) dimethacrylate are preferred. These may be used alone or in combination of two or more.

  Examples of trifunctional or higher (meth) acrylic acid ester polymerizable monomers or (meth) acrylamide polymerizable monomers include, for example, trimethylolpropane tri (meth) acrylate and trimethylolethane tri (meth) acrylate. , Trimethylolmethane tri (meth) acrylate, pentaerythritol tri (meth) acrylate, N, N ′-(2,2,4-trimethylhexamethylene) bis [2- (aminocarboxy) propane-1,3-diol] Tetra (meth) acrylate, pentaerythritol tetra (meth) acrylate, dipentaerythritol penta (meth) acrylate, 1,7-diaacryloyloxy-2,2,6,6-tetraacryloyloxymethyl-4-oxyheptane, and These (meth) acrylamides It is below. Among these, trimethylolpropane tri (meth) acrylate is preferable in terms of excellent miscibility with the (meth) acrylic acid ester polymer (a).

  The content of the polyfunctional (meth) acrylic acid ester polymerizable monomer (b-2) is such that the total amount of the polymerizable monomer (b) is 100% by weight. The amount of the acrylate-based polymerizable monomer (b-2) is preferably 1 to 55% by weight, more preferably 2 to 45% by weight, and still more preferably 5 to 40% by weight. When the blending amount of the polyfunctional (meth) acrylic acid ester-based polymerizable monomer (b-2) is 55% by weight or less, the cutting workability and the wear resistance of the cutting block are improved. In the present specification, the “total amount of the polymerizable monomer (b)” means the total amount of the (meth) acrylate-based polymerizable monomer contained in the entire cutting block. . In addition, in the polymerizable monomer (b) of the block for machining according to the present invention, other (meth) acrylic acid ester-based polymerizable monomers are polymerizable monomers (unless the effect of the present invention is impaired). Although less than 3% by weight (preferably less than about 1% by weight) may be blended with respect to the total amount of b), it is acidic when used for denture base applications, artificial tooth integrated denture base applications, and the like. The group-containing (meth) acrylic acid ester-based polymerizable monomer may be less than 1% by weight or less than 0.5% by weight in the polymerizable composition for a cutting block, It may be less than 0.1% by weight.

  In addition, the polyfunctional (meth) acrylic acid ester polymerizable monomer (b-2) used in the present invention is at least one (meta) having a urethane bond from the viewpoint of machinability and wear resistance. ) Acrylic acid ester (sometimes simply referred to as a (meth) acrylic acid ester having a urethane bond).

  The (meth) acrylic acid ester-based polymerizable monomer having a urethane bond, for example, is an addition reaction of a compound having an isocyanate group (—NCO) described later and a (meth) acrylate compound having a hydroxyl group (—OH). Can be easily synthesized.

  Examples of the compound having an isocyanate group include hexamethylene diisocyanate (HDI), tolylene diisocyanate (TDI), xylylene diisocyanate (XDI), diphenylmethane diisocyanate (MDI), isophorone diisocyanate (IPDI), trimethylhexamethylene diisocyanate (TMHMDI). , Tricyclodecane diisocyanate (TCDDI), adamantane diisocyanate (ADI), and the like.

  Examples of the (meth) acrylate compound having a hydroxyl group include 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 2-hydroxybutyl (meth) acrylate, 6-hydroxyhexyl (meth) acrylate, 10 -Hydroxydecyl (meth) acrylate, 3-chloro-2-hydroxypropyl (meth) acrylate, 2-hydroxy-3-phenoxypropyl (meth) acrylate, glycerin mono (meth) acrylate, N-hydroxyethyl (meth) acrylamide, N, N- (dihydroxyethyl) (meth) acrylamide, 2-hydroxy-3acryloyloxypropyl (meth) acrylate, 2,2-bis [4- [3- (meth) acryloyloxy-2-hydroxypropoxy Hydroxy (meth) such as phenyl] propane, 1,2-bis [3- (meth) acryloyloxy-2-hydroxypropoxy] ethane, pentaerythritol tri (meth) acrylate, dipentaerythritol tri- or tetra (meth) acrylate An acrylate compound etc. are mentioned.

  The addition reaction between the compound having an isocyanate group and the (meth) acrylate compound having a hydroxyl group can be carried out according to a known method, and is not particularly limited.

  As the (meth) acrylic acid ester having a urethane bond to be obtained, for example, as the polyfunctional (meth) acrylic acid ester having a urethane bond, one or more kinds selected from the aforementioned compounds having an isocyanate group Examples of the reaction product include any combination of one or more compounds selected from a compound and a (meth) acrylic acid ester having a hydroxyl group.

  Among these, 2,2,4-trimethylhexamethylenebis (2-carbamoyloxyethyl) dimethacrylate (commonly known as “UDMA”), N, N′— from the viewpoint of excellent machinability and impact resistance of the cured product. (2,2,4-trimethylhexamethylene) bis [2- (aminocarboxy) propane-1,3-diol] tetramethacrylate (commonly called “U4TH”), and alicyclic diisocyanate and 2-hydroxyethyl (meth) acrylate (E.g., a reaction product of IPD and 2-hydroxyethyl (meth) acrylate, a reaction product of TCDDI and 2-hydroxyethyl (meth) acrylate, and a reaction product of ADI and 2-hydroxyethyl (meth) acrylate). preferable. These may be used alone or in combination of two or more.

  In addition, a macromonomer having a (meth) acryl group at both ends of a polyurethane obtained by reacting a diol and a diisocyanate can also be used.

  The content of the (meth) acrylic acid ester having a urethane bond is preferably 20 to 100% by weight in the component (b-2) from the viewpoint of machinability and impact resistance, and is 40 to 100% by weight. More preferably, it is more preferably 60 to 100% by weight.

  The polymerizable monomer (b) can contain a polymerizable monomer other than the (meth) acrylic acid ester-based polymerizable monomer as long as the gist of the present invention is not impaired. Examples of such polymerizable monomers include esters such as α-cyanoacrylic acid, (meth) acrylic acid, α-halogenated acrylic acid, crotonic acid, cinnamic acid, sorbic acid, maleic acid, and itaconic acid. , (Meth) acrylamide, (meth) acrylamide derivatives, vinyl esters, vinyl ethers, mono-N-vinyl derivatives, styrene derivatives, and the like.

  Preferred embodiments of the block for machining according to the present invention include a (meth) acrylic acid ester polymer (a), a monofunctional (meth) acrylic acid ester polymerizable monomer (b-1), and A polymerizable monomer (b) containing a polyfunctional (meth) acrylic acid ester-based polymerizable monomer (b-2) and a polymerization initiator (c), and the (meth) acrylic acid ester-based The polymer (a) is a polymer having a Tg of 60 ° C. or higher, and the Tg of the polymer when the monofunctional (meth) acrylic acid ester polymerizable monomer (b-1) is a homopolymer is (Meth) acrylic acid ester monomer having a temperature of 60 ° C. or higher, and the polyfunctional (meth) acrylic acid ester-based monomer (b-2) has a urethane bond. A polymerizable monomer, the (meth) acrylic acid The content of the stealth polymer (a) is 2.5 to 40 parts by weight with respect to 100 parts by weight of the polymerizable monomer (b), and the monofunctional (meth) acrylic acid ester polymerizable monomer The content of the monomer (b-1) is 55 to 98% by weight when the total amount of the polymerizable monomer (b) is 100% by weight, and the polyfunctional (meth) acrylic acid ester-based polymerizability. The content of the monomer (b-2) is 2 to 45% by weight when the total amount of the polymerizable monomer (b) is 100% by weight, and the (meth) acrylic acid ester polymer. Examples thereof include a cutting block obtained by curing the composition in which (a) is dissolved in the polymerizable monomer (b).

  As a more preferable embodiment of the block for cutting according to the present invention, a (meth) acrylic acid ester polymer (a) and a monofunctional (meth) acrylic acid ester polymerizable monomer (b-1) are used. And a polymerizable monomer (b) containing a polyfunctional (meth) acrylic acid ester-based polymerizable monomer (b-2) and a polymerization initiator (c), and the (meth) acrylic acid ester The polymer in which the polymer (a) is a non-crosslinked polymer having a Tg of 60 ° C. or higher, and the monofunctional (meth) acrylic acid ester polymerizable monomer (b-1) is a homopolymer. Is a (meth) acrylate monomer having a Tg of 60 ° C. or higher, and the polyfunctional (meth) acrylate polymerizable monomer (b-2) has a urethane bond (meth) Acrylic acid ester-based polymerizable monomer, the (meth) The content of the crylate ester polymer (a) is 5 to 30 parts by weight with respect to 100 parts by weight of the polymerizable monomer (b), and the monofunctional (meth) acrylate ester polymerizable monomer The content of the monomer (b-1) is 60 to 95% by weight when the total amount of the polymerizable monomer (b) is 100% by weight, and the polyfunctional (meth) acrylic acid ester-based polymerizability. The content of the monomer (b-2) is 5 to 40% by weight when the total amount of the polymerizable monomer (b) is 100% by weight, and the (meth) acrylic acid ester polymer. Examples thereof include a cutting block obtained by curing the composition in which (a) is dissolved in the polymerizable monomer (b).

  The kind and content of each component in the cutting block according to the preferred embodiment can be appropriately selected and changed within a range separately described in the present specification.

Polymerization initiator (c)
The polymerization initiator (c) used in the present invention can be selected from polymerization initiators used in the general industry, and among them, polymerization initiators used for dental use are preferably used. In particular, the chemical polymerization initiator (c-1) and the photopolymerization initiator (c-2) can be used alone or in combination of two or more.

  Among the polymerization initiators (c), organic peroxides and azo compounds are preferably used as the chemical polymerization initiator (c-1). The organic peroxide and azo compound used as the chemical polymerization initiator (c-1) are not particularly limited, and known ones can be used. Typical organic peroxides include ketone peroxide, hydroperoxide, diacyl peroxide, dialkyl peroxide, peroxyketal, peroxyester, peroxydicarbonate, and the like.

  Examples of the ketone peroxide used as the chemical polymerization initiator (c-1) include methyl ethyl ketone peroxide, methyl isobutyl ketone peroxide, methyl cyclohexanone peroxide, and cyclohexanone peroxide.

  Examples of the hydroperoxide used as the chemical polymerization initiator (c-1) include 2,5-dimethylhexane-2,5-dihydroperoxide, diisopropylbenzene hydroperoxide, cumene hydroperoxide, and t-butyl. Examples include hydroperoxide and 1,1,3,3-tetramethylbutyl hydroperoxide.

  Examples of the diacyl peroxide used as the chemical polymerization initiator (c-1) include acetyl peroxide, isobutyryl peroxide, benzoyl peroxide, decanoyl peroxide, 3,5,5-trimethylhexanoyl peroxide, 2,4-dichlorobenzoyl peroxide, lauroyl peroxide, etc. are mentioned.

  Examples of the dialkyl peroxide used as the chemical polymerization initiator (c-1) include di-t-butyl peroxide, dicumyl peroxide, t-butylcumyl 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 Can be mentioned.

  Examples of the peroxyketal used as the chemical polymerization initiator (c-1) include 1,1-bis (t-butylperoxy) -3,3,5-trimethylcyclohexane, 1,1-bis (t- Butylperoxy) cyclohexane, 2,2-bis (t-butylperoxy) butane, 2,2-bis (t-butylperoxy) octane, and 4,4-bis (t-butylperoxy) valeric acid -N-butyl ester etc. are mentioned.

  Examples of the peroxy ester used as the chemical polymerization initiator (c-1) include α-cumyl peroxyneodecanoate, t-butyl peroxyneodecanoate, t-butyl peroxypivalate, 2, 2,4-trimethylpentylperoxy-2-ethylhexanoate, t-amylperoxy-2-ethylhexanoate, t-butylperoxy-2-ethylhexanoate, di-t-butylperoxyiso Phthalate, di-t-butylperoxyhexahydroterephthalate, t-butylperoxy-3,3,5-trimethylhexanoate, t-butylperoxyacetate, t-butylperoxybenzoate, and t-butylper Examples include oxyvaleric acid.

  Examples of the peroxydicarbonate used as the chemical polymerization initiator (c-1) include di-3-methoxyperoxydicarbonate, di-2-ethylhexylperoxydicarbonate, and bis (4-t-butylcyclohexyl). Examples include peroxydicarbonate, diisopropyl peroxydicarbonate, di-n-propyl peroxydicarbonate, di-2-ethoxyethyl peroxydicarbonate, and diallyl peroxydicarbonate.

  Examples of the azo compound used as the chemical polymerization initiator (c-1) include 2,2′-azobis (isobutyronitrile), 2,2′-azobis (2-methylbutyronitrile), 2,2 '-Azobis (2,4-dimethylvaleronitrile), 2,2'-azobis (4-methoxy-2,4-dimethylvaleronitrile), 1,1'-azobis (cyclohexane-1-carbonitrile), 4, 4′-azobis (4-cyanovaleric acid), 2,2-azobis [2- (2-imidazolin-2-yl) propane], 2,2′-azobis {2-methyl-N- [1,1- Bis (hydroxymethyl) -2-hydroxyethyl] propionamide} and the like.

  Among these organic peroxides and azo compounds, diacyl peroxides, hydroperoxides, and azo compounds are chemical polymerization initiators (c) because of the ability to generate radicals in the presence of the (meth) acrylic acid ester polymer (a). Hydroperoxide is more preferable because it is preferably used as -1) and the discoloration of the cured product and the generation of bubbles are suppressed. Among them, benzoyl peroxide, cumene hydroperoxide, t-butyl hydroperoxide, 1,1,3,3-tetramethylbutyl hydroperoxide and 2,2′-azobis (isobutyronitrile), 2,2 ′ -Azobis (2-methylbutyronitrile) is preferably used as the chemical polymerization initiator (c-1), and 1,1,3,3-tetramethylbutyl hydroperoxide is more preferably used.

  As the photopolymerization initiator (c-2), (bis) acylphosphine oxides, thioxanthones or quaternary ammonium salts of thioxanthones, ketals, α-diketones, coumarins, anthraquinones, benzophenone, benzoin, Examples thereof include benzoin alkyl ether compounds, benzoin phenyl ether compounds, and α-aminoketone compounds. These may be used alone or in combination of two or more.

  Although the compounding quantity of the polymerization initiator (c) in this invention is not specifically limited, From a polymeric viewpoint, the (meth) acrylic acid ester type | system | group polymerizable monomer (b) (meth) acrylic acid ester total amount 100 weight It is preferable that 0.001-30 weight part of polymerization initiators (c) are contained with respect to parts. When the compounding quantity of a polymerization initiator (c) is less than 0.001 weight part, superposition | polymerization may not fully advance and there exists a possibility that machinability may fall. The amount of the polymerization initiator (c) is more preferably 0.05 parts by weight or more, and further preferably 0.1 parts by weight or more. On the other hand, when the blending amount of the polymerization initiator (c) exceeds 30 parts by weight, there is a risk of causing precipitation from the cutting block if the polymerization performance of the polymerization initiator itself is low. The amount of the polymerization initiator (c) is more preferably 20 parts by weight or less, further preferably 15 parts by weight or less, and particularly preferably 10 parts by weight or less.

Inorganic filler (d)
In order to improve the machinability, the cutting block of the present invention preferably contains an inorganic filler (d).

  Examples of the inorganic filler (d) include quartz, silica, alumina, silica-titania, silica-titania-barium oxide, silica-zirconia, silica-alumina, lanthanum glass, borosilicate glass, soda glass, barium glass, Strontium glass, glass ceramic, aluminosilicate glass, barium boroaluminosilicate glass, strontium boroaluminosilicate glass, fluoroaluminosilicate glass, calcium fluoroaluminosilicate glass, strontium fluoroaluminosilicate glass, barium fluoroaluminosilicate glass, and strontium calcium fluoroalumino Examples thereof include silicate glass. These can also be used individually or in mixture of 2 or more types. The shape of the inorganic filler (d) is not particularly limited, and an amorphous filler or a spherical filler can be appropriately selected and used. Among these, quartz and silica are preferably used from the viewpoint of machinability and transparency.

  The inorganic filler (d) is surface-treated with a known surface treatment agent such as a silane coupling agent in advance as necessary in order to adjust the miscibility with the (meth) acrylic acid ester polymerizable monomer (b). It may be used after that. Examples of the surface treatment agent include dimethyldichlorosilane, vinyltrimethoxysilane, vinyltriethoxysilane, vinyltrichlorosilane, vinyltri (β-methoxyethoxy) silane, 3-methacryloyloxypropyltrimethoxysilane, and 11-methacryloyloxyun. Examples include decyltrimethoxysilane, 3-glycidoxypropyltrimethoxysilane, 3-mercaptopropyltrimethoxysilane, and 3-aminopropyltriethoxysilane.

  As the surface treatment method, a known method can be used without any particular limitation. For example, the surface treatment agent is spray-added while vigorously stirring the inorganic filler, the inorganic filler and the above-mentioned solvent in a suitable solvent, and the like. After dispersing or dissolving the surface treatment agent, the solvent is removed, or the alkoxy group of the surface treatment agent is hydrolyzed with an acid catalyst in an aqueous solution to convert it to a silanol group, and the inorganic filler in the aqueous solution There is a method of removing water after adhering to the surface. In any method, heating is usually performed in the range of 50 ° C. to 150 ° C., whereby the reaction between the surface of the inorganic filler and the surface treatment agent is completed, and the surface treatment can be performed.

  The average particle diameter of the inorganic filler (d) is preferably 0.001 to 0.10 μm, more preferably 0.002 to 0.09 μm, from the viewpoint of machinability and transparency of the cutting block. 0.05 μm is more preferable, and 0.005 to 0.04 μm is particularly preferable.

  In the present specification, the average particle diameter of the filler can be determined by a laser diffraction scattering method or observation of particles by an electron microscope. Specifically, the laser diffraction scattering method is convenient for measuring the particle size of particles of 0.10 μm or more, and the electron microscope observation is simple for measuring the particle system of ultrafine particles of 0.10 μm or less. 0.10 μm is a value measured by a laser diffraction scattering method.

  The laser diffraction scattering method can be measured by, for example, a 0.2% sodium hexametaphosphate aqueous solution as a dispersion medium using a laser diffraction particle size distribution analyzer (SALD-2100: manufactured by Shimadzu Corporation).

  The electron microscope observation is, for example, taking a scanning electron microscope (Hitachi, S-4000 type) photograph of particles, and analyzing the particle diameter of particles (200 or more) observed in the unit field of view of the photograph. It can obtain | require by measuring using a type | formula particle size distribution measurement software (Macview (Mounttech Co., Ltd.)). At this time, the particle diameter of the particles is obtained as an arithmetic average value of the longest length and the shortest length of the particles, and the average primary particle diameter is calculated from the number of particles and the particle diameter.

  The blending amount of the inorganic filler (d) is not particularly limited, but from the viewpoint of the handleability of the composition before curing and the mechanical strength of the block for cutting, the total amount of the component (a) and the component (b) is 100 parts by weight. On the other hand, it is preferably 0.1 to 30 parts by weight or less, more preferably 0.5 to 20 parts by weight or less, and further preferably 1.0 to 15 parts by weight or less. When the content of the filler (d) is 30 parts by weight or less, the handleability of the composition before curing and the impact resistance of the block are kept good. Further, the amount of the inorganic filler (d) is preferably 18% by weight or less, more preferably 15% by weight or less, further preferably 10% by weight or less, and particularly preferably 9.5% by weight or less based on the entire composition. .

  In the cutting block of the present invention, a filler other than the inorganic filler (d) may be blended for the purpose of adjusting mechanical performance and the like. Examples of fillers other than the inorganic filler (d) include organic fillers and organic-inorganic composite fillers. On the other hand, the cutting block of the present invention may be an embodiment containing only the inorganic filler (d) as the inorganic filler, or an embodiment containing only the inorganic filler (d) as the filler.

  Examples of the organic filler material include polymethyl methacrylate, polyethyl methacrylate, methyl methacrylate-ethyl methacrylate copolymer, cross-linked polymethyl methacrylate, cross-linked polyethyl methacrylate, polyester, polyamide, polycarbonate, Polyphenylene ether, polyoxymethylene, polyvinyl chloride, polystyrene, polyethylene, polypropylene, chloroprene rubber, nitrile rubber, ethylene-vinyl acetate copolymer, styrene-butadiene copolymer, acrylonitrile-styrene copolymer, and acrylonitrile-styrene- A butadiene copolymer is mentioned, These can be used individually or in mixture of 2 or more types. The shape of the organic filler is not particularly limited, and the particle size of the filler can be appropriately selected and used.

  The organic-inorganic composite filler can be obtained, for example, by adding a monomer to the inorganic filler in advance, forming a paste, polymerizing, and pulverizing. As the organic-inorganic composite filler, for example, TMPT filler (filler obtained by mixing and polymerizing trimethylolpropane methacrylate and silica filler and then pulverizing) can be used. The shape of the organic-inorganic composite filler is not particularly limited, and the particle diameter of the filler can be appropriately selected.

Polymerization accelerator (e)
The composition used for the block for cutting according to the present invention can contain a polymerization accelerator (e) for the purpose of adjusting the polymerizability. Examples of the polymerization accelerator (e) include thiourea compounds, amines, transition metal compounds, tin compounds, aldehydes, organophosphorus compounds, borate compounds, barbituric acid derivatives, and triazine compounds. These may be used alone or in combination of two or more.

  Examples of the thiourea compound used as the polymerization accelerator (e) include 1- (2-pyridyl) -2-thiourea, thiourea, methylthiourea, ethylthiourea, N, N′-dimethylthiourea, N, N. '-Diethylthiourea, N, N'-di-n-propylthiourea, N, N'-dicyclohexylthiourea, trimethylthiourea, triethylthiourea, tri-n-propylthiourea, tricyclohexylthiourea, tetramethylthiourea, Examples include tetraethylthiourea, tetra-n-propylthiourea, tetracyclohexylthiourea, 3,3-dimethylethylenethiourea, and 4,4-dimethyl-2-imidazolidinethione. Among these, 1- (2-pyridyl) -2-thiourea from the viewpoint of moderate curability of the composition used for the block for machining in the presence of the (meth) acrylic acid ester polymer (a) Alternatively, 4,4-dimethyl-2-imidazolidinethione is preferably used as the polymerization accelerator (e).

  Examples of amines used as the polymerization accelerator (e) include primary aliphatic amines such as n-butylamine, n-hexylamine, and n-octylamine; diisopropylamine, dibutylamine, N-methylethanolamine, and the like. Secondary aliphatic amine: N-methyldiethanolamine, N-ethyldiethanolamine, Nn-butyldiethanolamine, N-lauryldiethanolamine, 2- (dimethylamino) ethyl methacrylate, N-methyldiethanolamine dimethacrylate, N-ethyldiethanolamine di Methacrylate, triethanolamine monomethacrylate, triethanolamine dimethacrylate, triethanolamine trimethacrylate, triethanolamine, trimethylamine, triethylamine, tributy Tertiary aliphatic amines such as amines. N, N-bis (2-hydroxyethyl) -3,5-dimethylaniline, N, N-di (2-hydroxyethyl) -p-toluidine, N, N-bis (2-hydroxyethyl) -3,4 -Dimethylaniline, N, N-bis (2-hydroxyethyl) -4-ethylaniline, N, N-bis (2-hydroxyethyl) -4-isopropylaniline, N, N-bis (2-hydroxyethyl)- 4-t-butylaniline, N, N-bis (2-hydroxyethyl) -3,5-di-isopropylaniline, N, N-bis (2-hydroxyethyl) -3,5-di-t-butylaniline N, N-dimethylaniline, N, N-dimethyl-p-toluidine, N, N-dimethyl-m-toluidine, N, N-diethyl-p-toluidine, N, N-dimethyl-3,5-dimethyl Aniline, 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, ethyl 4- (N, N-dimethylamino) benzoate, methyl 4- (N, N-dimethylamino) benzoate, 4- (N, N-dimethylamino) benzoic acid n-butoxyethyl, 4- (N, N-dimethylamino) benzoic acid 2-[(meth) acryloyloxy] ethyl, 4-N, N-dimethylaminobenzophenone, and 4-dimethylamino And aromatic amines such as butyl benzoate. Among these, from the viewpoint of imparting excellent curability to the composition used for the block for cutting, 4- (N, N-dimethylamino) benzoate, 4- (N, N-dimethylamino) benzoic acid At least one selected from the group consisting of n-butoxyethyl and 4-N, N-dimethylaminobenzophenone is preferably used.

  Examples of the transition metal compound used as the polymerization accelerator (e) include vanadium compounds, copper compounds, and cobalt compounds. Examples of vanadium compounds include vanadium tetroxide (IV), vanadyl acetylacetonate (IV), vanadyl oxalate (IV), vanadyl sulfate (IV), and oxobis (1-phenyl-1,3-butanedionate). Examples include vanadium (IV), bis (maltolate) oxovanadium (IV), vanadium pentoxide (V), and sodium metavanadate (V). Examples of the copper compound include acetylacetone copper, cupric acetate, copper oleate, cupric chloride, and cupric bromide. Examples of the cobalt compound include acetylacetone cobalt, cobalt acetate, cobalt oleate, cobalt chloride, and cobalt bromide.

  Examples of the tin compound include di-n-butyltin dimaleate, di-n-octyltin dimaleate, di-n-octyltin dilaurate, and di-n-butyltin dilaurate.

  Examples of aldehydes used as the polymerization accelerator (e) include terephthalaldehyde and benzaldehyde derivatives. Examples of the benzaldehyde derivative include dimethylaminobenzaldehyde, p-methyloxybenzaldehyde, p-ethyloxybenzaldehyde, pn-octyloxybenzaldehyde, and the like.

  Among these polymerization accelerators (e), a thiourea compound is particularly preferably used from the viewpoint of easy adjustment of curability and moldability of a block for cutting, and among these, 1- (2-pyridyl) 2-thiourea and 4,4-dimethyl-2-imidazolidinethione are most preferably used as the polymerization accelerator (e).

  Although the compounding quantity in the composition used for the block for cutting of a polymerization accelerator (e) is not specifically limited, From viewpoints of sclerosis | hardenability etc. of the composition obtained, 100 weight part of total amounts of a polymerizable monomer (b) are obtained. In contrast, the polymerization accelerator (e) is preferably contained in an amount of 0.001 to 10 parts by weight. When the compounding quantity of a polymerization accelerator (e) is less than 0.001 weight part, superposition | polymerization may not fully advance and there exists a possibility that a molded object may not be obtained. The blending amount of the polymerization accelerator (e) is preferably 0.01 parts by weight or more. On the other hand, when the blending amount of the polymerization accelerator (e) exceeds 10 parts by weight, there is a possibility that a molded body free from bubbles or shrinkage cannot be obtained because the polymerization is too early. As for the compounding quantity of a polymerization accelerator (e), 1.0 weight part or less is more preferable.

  Moreover, a well-known additive can be mix | blended with the polymeric composition for dental cutting blocks of this invention in the range which does not reduce performance. Examples of such additives include polymerization inhibitors, antioxidants, colorants (pigments, dyes, fibers, etc.), ultraviolet absorbers, organic solvents, and thickeners. In the present invention, for example, a denture base having a transparent feeling can be obtained by using a polymerizable composition containing a colorant.

  Examples of the polymerization inhibitor include hydroquinone, hydroquinone monomethyl ether, dibutyl hydroquinone, dibutyl hydroquinone monomethyl ether, t-butylcatechol, 2-t-butyl-4,6-dimethylphenol, 2,6-di-t-butylphenol, And 3,5-di-t-butyl-4-hydroxytoluene. The content of the polymerization inhibitor is preferably 0.001 to 1.0 part by weight with respect to 100 parts by weight of the total amount of the (meth) acrylic acid ester polymer (a) and the polymerizable monomer (b).

By mixing the above components, a polymerizable composition for a block for cutting is prepared. Usually, after the (meth) acrylic acid ester polymer (a) is dissolved in the polymerizable monomer (b), other components are mixed with this solution at room temperature to prepare a polymerizable composition. To do. Dissolution of (meth) acrylate polymer (a) in polymerizable monomer (b) depending on the type of (meth) acrylate polymer (a) and polymerizable monomer (b) used In general, in order to dissolve the (meth) acrylate polymer (a) in the polymerizable monomer (b), it is necessary to stir the mixture at room temperature for a long time. Therefore, the stirring time for dissolving the mixture can be shortened by heating the mixture to such an extent that the polymerizable monomer (b) does not volatilize (for example, about 40 ° C.). In the present invention, the (meth) acrylic acid ester polymer (a) is excellent in the cutting block obtained by curing the polymerizable composition in which the polymerizable monomer (b) is dissolved. Machinability is developed. In this specification, the (meth) acrylic acid ester polymer (a) is dissolved in the polymerizable monomer (b) means that it is polymerized with the (meth) acrylic acid ester polymer (a). When the mixture of the monomer (b) is passed through a nylon mesh (110 pieces / 2.54 cm ² , fiber diameter 70 μm) at room temperature, the insoluble matter (gel content) remaining without passing on the nylon mesh ) Is less than 1% by weight relative to the weight of the mixture.

  The polymerizable composition thus prepared is molded into a block shape, and further cured by light irradiation or heating to obtain a cutting block. For molding the polymerizable composition, for example, a metal, glass, or resin mold and lid are prepared. The mold has a cavity. The cavity is formed, for example, in a prismatic shape, a cylindrical shape, a square plate shape, or a disc shape. After the cavity of the mold is filled with the composition, the inside of the cavity is decompressed to remove bubbles from the composition. Next, the composition is polymerized by light irradiation or heating under pressure or normal pressure in a state where the mold is covered and the cavity is closed. Thereby, a block is obtained from a prismatic, columnar, prismatic, or disk-shaped cavity. In the case of light irradiation, a light source at the time of molding can be appropriately selected, and examples thereof include visible light and ultraviolet light. In the case of heating, the heating temperature at the time of molding can be adjusted as appropriate, and is, for example, in the range of 50 to 150 ° C. Although a pressure can be suitably adjusted at the time of shaping | molding, it is the range of a normal pressure-200 MPa, for example. The light amount, temperature, and pressure at the time of molding may be changed over time as necessary. Also, instead of forming a mold, a resin or rubber packing hollowed out in a prismatic shape, a cylindrical shape, a square plate shape, or a disc shape, or a resin or rubber tube is deformed into a square shape or a circular shape to form a metal. After being sandwiched between plates made of glass, glass, or resin, the composition is filled into a packing or tube and treated in the same manner as in the case of using the above-described mold to obtain a block.

In the present invention, cutting block its volume is formed in such a way that the range of 15cm ³ or 500 cm ³ or less. Therefore, mold comprising a cavity having a 15cm ³ or more 500 cm ³ or less of the volume is used. Further, the packing tube is machined to have a 15cm ³ or more 500 cm ³ or less volume. The volume of the cutting block, from the viewpoint of machinability and cracking occurs is preferably in the range of 15cm ³ or 500 cm ³ or less, more preferably in the range of 20 cm ³ or more 450 cm ³ or less, 50 cm ³ More preferably, it is in the range of 400 cm ³ or less.

  The cutting block is cut by a CAD / CAM system (CAD / CAM device) to produce a denture base and an artificial tooth integrated denture base. When the cutting block is cut by the CAD / CAM system, a uniform denture base and an artificial tooth-integrated denture base can be obtained as compared with the case of manual work.

A range for cutting blocks in volume of 15cm ³ or 500 cm ³ or less of the present invention, it becomes possible to manufacture the cutting block of large size, it is possible to form a denture. Moreover, in this invention, generation | occurrence | production of a crack is suppressed at the time of superposition | polymerization, although it is a large size as mentioned above. Furthermore, since it is excellent in cutting workability, it is possible to cut in a short time while having a large size.

  The bending strength of the cutting block of the present invention is preferably 80 MPa or more, and more preferably 100 MPa or more. The method for measuring the bending strength is as described in Examples described later.

The Charpy impact strength of the cutting block of the present invention, a value of greater than 20 kJ / m ^2, preferably 25 kJ / m ² or more, 30 kJ / m ² or more is more preferable. The measuring method of Charpy impact strength is as described in the examples described later.

  The present invention includes embodiments in which the above-described configurations are variously combined within the technical scope of the present invention as long as the effects of the present invention are exhibited.

  Hereinafter, the present invention will be described in detail with reference to examples. The present invention is not limited to these examples.

  Next, each component used for the polymerizable composition which concerns on an Example or a comparative example is demonstrated below with an abbreviation and abbreviation.

[(Meth) acrylic acid ester polymer (a)]
PMMA: non-crosslinked polymethyl methacrylate powder, “Hyperl M4003” manufactured by Negami Kogyo Co., Ltd., Mw 1000000, glass transition temperature 105 ° C.
PMMA-PEMA: non-crosslinked polymethyl methacrylate-polyethyl methacrylate copolymer powder, “Hyperl M4501” manufactured by Negami Kogyo Co., Ltd., Mw 1000000, glass transition temperature 84 ° C.
PEMA: non-crosslinked polyethyl methacrylate polymer powder, “Hyperl M5001” manufactured by Negami Kogyo Co., Ltd., Mw 300000, glass transition temperature 65 ° C.

[Monofunctional (meth) acrylic ester polymerizable monomer (b-1)]
MMA: methyl methacrylate homopolymer glass transition temperature 105 ° C.
TBM: glass transition temperature of t-butyl methacrylate homopolymer 107 ° C.
IBM: Glass transition temperature of isobornyl methacrylate homopolymer 180 ° C

[Polyfunctional (meth) acrylic acid ester-based polymerizable monomer (b-2)]
UDMA: 2,2,4-trimethylhexamethylene bis (2-carbamoyloxyethyl) dimethacrylate U4TH: N, N ′-(2,2,4-trimethylhexamethylene) bis [2- (aminocarboxy) propane-1 , 3-diol] tetramethacrylate TCDDM: reaction product of tricyclodecane diisocyanate and 2-hydroxyethyl methacrylate HD: 1,6-hexanediol dimethacrylate

[Chemical polymerization initiator (c-1)]
THP: 1,1,3,3-tetramethylbutyl hydroperoxide CHP: cumene hydroperoxide

[Inorganic filler (d)]
(D) -1: Dimethyldichlorosilane surface-treated colloidal silica powder (“R972” manufactured by Nippon Aerosil Co., Ltd.) Average particle size 0.016 μm
(D) -2: Colloidal silica powder (“Aerosil 380” manufactured by Nippon Aerosil Co., Ltd.) Average particle size 0.008 μm

[Polymerization accelerator (e)]
DMETU: 4,4-dimethyl-2-imidazolidinethione PTU: 1- (2-pyridyl) -2-thiourea

[Polymerization inhibitor]
BHT: 3,5-di-tert-butyl-4-hydroxytoluene

[Examples 1 to 11 and Comparative Examples 1 to 4]
Each component shown in Table 1 and Table 2 is mixed under normal temperature (20 ° C. ± 15 ° C., JIS (Japanese Industrial Standards) Z 8703-1983), and each cutting according to Examples 1 to 11 and Comparative Examples 1 to 4 is performed. A composition for a processing block was prepared. About Examples 1-11 and 2-3, it is the method described in the evaluation method of the solubility of the below-mentioned (meth) acrylic acid ester type polymer (a), (meth) acrylic acid ester type polymer (a ) Was dissolved in the polymerizable monomer (b) (insoluble in Comparative Example 3), and the resulting mixture was mixed with the remaining components at room temperature to prepare a composition. Next, for each of the compositions of Examples 1 to 7 and Comparative Examples 1 to 4, a 3.3 cm thick silicon tube was rolled into a circular shape having a diameter of 8 cm, and sandwiched between glass plates having a length and width of 25 cm and a thickness of 0.5 cm, After fixing and tightening with a fastening metal fitting and adjusting the clearance of the glass plate to 3.0 cm, a notch was previously provided in the silicon tube, the composition was poured from there, and the water was poured into water at 30 ° C. for 12 hours, 120 It heated for 2 hours with the oven at 0 degreeC, and produced the disk shaped block of diameter 8cm which concerns on Examples 1-7 and Comparative Examples 1-4, thickness 3.0cm, and volume 150cm < ³ >. In Examples 8 and 10, the treatment was performed in the same manner as in Examples 1 to 7, except that the silicon tube was made into a circle having a diameter of 10 cm. In Examples 9 and 11, the treatment was performed in the same manner as in Examples 1 to 7, except that the silicon tube was circular with a diameter of 12 cm.

<Solubility of (meth) acrylic acid ester polymer (a) in polymerizable monomer (b)>
Among the components shown in Examples 1 to 11 in Table 1 and Comparative Examples 2 and 3 in Table 2, the (meth) acrylic acid ester polymer (a) and the polymerizable monomer (b) are listed in the table. After stirring the mixture at 40 ° C. for 12 hours, the mixture was passed through a nylon mesh (110 pieces / 2.54 cm ² , fiber diameter 70 μm, N-NO.110S manufactured by Meshtec) at room temperature, and the nylon mesh was passed through. The weight of the insoluble matter (gel content) remaining without passing above was measured. In the case of the mixtures of Examples 1 to 11 and Comparative Example 2, the weight of the insoluble matter (gel content) remaining on the nylon mesh was less than 1% by weight based on the weight of the mixture, both of which were (meth) acrylic acid. It was confirmed that the ester polymer (a) was dissolved in the polymerizable monomer (b). On the other hand, the mixture of Comparative Example 3 cannot pass through the nylon mesh, and the (meth) acrylic acid ester polymer (a) is only swelled in the polymerizable monomer (b) but not dissolved. I was able to confirm.

<Crack evaluation>
In each of the examples and comparative examples, five cutting blocks were obtained by repeating molding of the composition five times. The appearance of these blocks was visually observed, and when one of the five blocks had cracks, it was evaluated as “Yes”, and when no crack was observed in all the blocks, it was evaluated as “None”. .

<Machinability evaluation (polishing depth, cutting waste)>
Using ULTIMATE500 (manufactured by Nakanishi) equipped with diamond point HP model number 25 (manufactured by Matsukaze), the diamond point HP was pressed perpendicularly to the plane of the block with a load of 500 g in the air at a load of 500 g, and the grinding depth after 5 seconds Was measured. In addition, the shape of the cutting waste and the presence or absence of winding of the cutting waste around the diamond point HP are visually observed. If the cutting waste is powdery and has no winding, it is “good”, and the cutting waste is wound in a string or hook shape. An item with a defect was defined as “bad”.

<Impact resistance evaluation (Charpy impact strength)>
A test piece having a thickness of 4 mm, a length of 80 mm, and a width of 10 mm was cut out from each block obtained in the examples and comparative examples. About the obtained test piece, it evaluated by the Charpy impact test (there is no notch and a flatwise method) based on JISK7111: 2012 1st part (non-instrumentation test). The test piece was five pieces, and the average was made Charpy impact strength. Excellent impact resistance as long as the value of Charpy impact strength greater than 20 kJ / m ^2, preferably 25 kJ / m ² or more, 30 kJ / m ² or more is more preferable.

<Abrasion resistance test (sliding durability)>
A test piece having a thickness of 2 mm, a length of 30 mm, and a width of 20 mm was cut out from each block obtained in the examples and comparative examples. The surface of the test piece was polished with No. 1500 water-resistant abrasive paper, and this polished surface was buffed at 3000 rpm for 20 seconds using a technical polishing box (KAW Corporation, EWL80) to prepare a test piece. As an abrasive material, POHSENY HYDON (manufactured by Tokyo Teeth Co., Ltd.) was used. The glossiness (G1) of the test piece before the abrasion test was shown by using a gloss meter (VG-107 manufactured by Nippon Denshoku Industries Co., Ltd.) as a ratio when the mirror was 100%. The measurement angle was 60 °. Using a toothbrush wear tester (manufactured by Daiei Kagaku Seiki Co., Ltd.), the test piece was subjected to a commercial toothpaste / distilled water = 60/40 parts by weight suspension and a commercially available denture brush under a load of 250 g. , A 40,000 cycle wear test was conducted. The glossiness (G2) of the surface of the test piece after the wear test was shown by the same method as before the wear test. Lubricating durability (%) was expressed as {(G2) × 100} / (G1) from the glossiness of the surface of the test piece before and after the abrasion test. Lubrication durability of 70% or more is preferred.

<Bending strength evaluation>
A test piece having a height of 2.0 mm, a width of 2.0 mm and a length of 25 mm was cut out from each of the blocks obtained in Examples and Comparative Examples. About the obtained test piece, it evaluated by the bending test based on ISO4049: 2000. That is, a bending test was performed at a crosshead speed of 1 mm / min using a universal testing machine (manufactured by Shimadzu Corporation, Autograph AG-100kNI). The bending strength of the block is preferably 80 MPa or more, and more preferably 100 MPa or more.

<Transparency test>
A test piece having a thickness of 1.0 mm and a diameter of 15 mm was cut out from each block obtained in the examples and comparative examples. About the obtained test piece, transparency (DELTA) L was measured using the spectral color difference meter (The Nippon Denshoku Industries Co., Ltd. make, SE2000, D65 light source). Transparency ΔL is defined by the following equation. In addition, in order to ensure high aesthetics, the transparency (ΔL) needs to be 50 or more. The results are shown in Table 1 and Table 2, respectively.
ΔL = L * W-L * B
L * W represents the lightness index L * in the L * a * b * color system measured with a white background, and L * B represents the lightness in the L * a * b * color system measured with a black background. Represents the index L *.

  As shown in Tables 1 and 2, the cutting blocks in Examples 1 to 11 were free from cracks, and the test pieces obtained therefrom had cutting properties, impact resistance, wear resistance, mechanical strength and Excellent transparency. In particular, the tooth cutting blocks according to Examples 1 to 11 were able to suppress the occurrence of cracks as compared with the cutting blocks according to Comparative Examples 1 and 4. The cutting workability of the cutting blocks according to Examples 1 to 11 was superior to the cutting workability of the cutting blocks according to Comparative Examples 2 to 3. The impact resistance of the cutting blocks according to Examples 1 to 11 was superior to the impact resistance of the cutting blocks according to Comparative Examples 1 to 4. The wear resistance of the cutting blocks according to Examples 1 to 11 was superior to the wear resistance of the cutting blocks according to Comparative Examples 1 to 4. The mechanical strength of the cutting blocks according to Examples 1 to 11 was superior to the mechanical strength of the cutting block according to Comparative Example 2. The cutting blocks according to Examples 1 to 11 showed higher transparency than the cutting block according to Comparative Example 4, and were excellent in aesthetics.

  The block for cutting according to the present invention is free from cracks and excellent in machinability at the time of cutting, and also excellent in impact resistance, wear resistance, and aesthetics when used in the oral cavity. Further, the cutting block of the present invention is excellent in mechanical strength in addition to the above characteristics. Therefore, it is particularly suitable for a denture base block in dental treatment used by cutting with a CAD / CAM system.

Claims (8)

  (Meth) acrylic acid ester polymer (a), monofunctional (meth) acrylic acid ester polymerizable monomer (b-1) and polyfunctional (meth) acrylic acid ester polymerizable monomer A polymerizable monomer (b) containing (b-2) and a polymerization initiator (c) are contained, and the content of the (meth) acrylic acid ester polymer (a) is the polymerizable monomer. (B) 1 to 50 parts by weight with respect to 100 parts by weight and a composition in which the (meth) acrylic acid ester polymer (a) is dissolved in the polymerizable monomer (b) Cutting block obtained by curing.   The block for cutting according to claim 1, wherein a glass transition temperature of the homopolymer of the monofunctional (meth) acrylic acid ester-based polymerizable monomer (b-1) is 60 ° C or higher.   The said polyfunctional (meth) acrylic-ester type | system | group polymeric monomer (b-2) contains the (meth) acrylic-ester type | system | group polymeric monomer which has a urethane bond, The Claim 1 or 2 Block for cutting.   The block for cutting according to any one of claims 1 to 3, further comprising an inorganic filler (d) having an average particle diameter of 0.001 to 0.10 µm. Volume is 15cm ³ or more 500 cm ³ or less, for cutting blocks according to any one of claims 1-4.   The cutting block according to any one of claims 1 to 5, which is for a denture base.   A dental prosthesis produced from the cutting block according to any one of claims 1 to 5.   A denture base obtained by cutting the block for cutting according to any one of claims 1 to 5.