Dental polymerizable composition

Abstract

The present invention provides a dental polymerizable composition which is excellent in terms of toughness and water resistance of a cured product, and a cured product of which has little eluate. The present invention relates to a dental polymerizable composition which contains a polyfunctional (meth)acrylic polymerizable compound (A) and a photopolymerization initiator (B) that does not contain a phosphine oxide skeleton. It is preferable that the photopolymerization initiator (B) that does not contain a phosphine oxide skeleton contains a Norrish type II photopolymerization initiator. It is preferable that the polyfunctional (meth)acrylic polymerizable compound (A) contains a polyfunctional (meth)acrylic polymerizable compound (A)-I that has a molecular weight of less than 1000 and / or a polyfunctional (meth)acrylic polymerizable compound (A)-II that has a molecular weight of 1,000 or more.

Description

Dental polymerizable composition

[0001] The present invention relates to a dental polymerizable composition, particularly to a dental polymerizable composition for stereolithography containing a large amount of a photopolymerization initiator. More specifically, the composition can provide cured products that are excellent in strength, toughness, water resistance, and color tone, and have minimal elution from the cured product, resulting in excellent biological safety. The composition is ideal for dental stereolithography materials, particularly dental occlusal splints, denture base materials, and treatment devices for sleep apnea syndrome.

[0002] Dental polymerizable compositions are used as filling and restorative materials for tooth defects and carious cavities, as adhesives for fixing the filling and restorative materials to teeth, as restorative materials for metal or ceramic crowns called inlays or crowns, as luting agents for fixing the restorative materials for crowns to teeth, and as dental materials such as dental occlusal splint materials and denture base materials. Dental polymerizable compositions generally contain a (meth)acrylic polymerizable monomer, a polymerization initiator, and, if necessary, a filler such as an inorganic compound, and other additives.

[0003] Photopolymerization initiators and chemical polymerization initiators are used as polymerization initiators, and dental polymerizable compositions are broadly classified into photopolymerizable compositions containing a photopolymerization initiator, chemically polymerizable compositions containing a chemical polymerization initiator, and compositions having both photopolymerizability and chemical polymerizability containing both initiators, but photopolymerization initiators are an essential component of most dental materials.

[0004] In recent years, many proposals have been made regarding a method for producing a three-dimensional object by repeating the steps of supplying a required amount of controlled light energy to a liquid photocurable resin composition containing a photopolymerization initiator to cure it into a thin layer, supplying another liquid photocurable composition on top of it, and then irradiating it with light under control to cure the layer into a thin layer, known as an optical three-dimensional modeling method (stereolithography).

[0005] A typical method for optically producing a three-dimensional object is liquid vat stereolithography, in which the liquid surface of a liquid photocurable composition placed in a container is selectively irradiated with a computer-controlled ultraviolet laser to obtain a desired pattern, curing the composition to a predetermined thickness and forming a cured layer, and then a layer of liquid photocurable composition is supplied on top of the cured layer, irradiated with an ultraviolet laser in the same manner as above and cured in the same manner to form successive cured layers, repeating this lamination process to produce a three-dimensional object of the final shape. This method has attracted considerable attention in recent years because it can produce the desired three-dimensional object easily, in a relatively short time, and with high accuracy, even if the shape of the object is quite complex.

[0006] The applications of three-dimensional objects obtained by stereolithography have expanded from mere concept models to test models, prototypes, and final products. In particular, in the field of dental materials, applications of stereolithography are expected to be expanded for dental occlusal splints, denture bases, and mouthpiece-shaped materials for treating sleep disorders, such as devices to prevent teeth grinding and treat sleep apnea syndrome, because the shapes vary from patient to patient and are complex.

[0007] Dental occlusal splints are devices worn to correct the alignment of teeth and jaw position, such as orthodontic mouthpieces and aligners, devices worn on the teeth to prevent tooth wear due to teeth grinding, and mouthguards worn in the oral cavity to reduce trauma caused by large external forces applied to the teeth and jawbone during contact sports and to protect the stomatognathic system and brain. In recent years, the use of orthodontic devices has rapidly expanded due to their aesthetic appeal and the ability to be removed whenever desired.

[0008] Denture base materials are materials used in the gum area when wearing dentures due to tooth loss. In recent years, the demand for dentures has increased dramatically due to the increase in the elderly population.

[0009] A device for treating sleep apnea syndrome is an apparatus (oral appliance: OA) that is attached to the teeth while sleeping at night to treat obstructive sleep apnea syndrome (OSAS), and its use is rapidly increasing.

[0010] Dental materials, particularly dental occlusal splints, denture base materials, and OAs, are commonly required to have strength, toughness, water resistance, and color tone. Low strength leads to significant deflection and deformation during use, resulting in an uncomfortable fit. Loss of toughness leads to problems such as increased susceptibility to breakage due to occlusal loads and deformation during use, necessitating frequent remaking. Loss of water resistance also leads to problems such as a decline in mechanical properties during use, resulting in increased susceptibility to deformation and breakage during use, making the material unsuitable for practical use.

[0011] Furthermore, oral impressions are typically required when producing dental occlusal splints, denture base materials, and sleep apnea treatment devices. However, these procedures pose challenges, such as the discomfort they cause to patients and the need for skilled technicians. In recent years, advances in digital technology have led to the application of optical intraoral scanning for impression taking and the use of optical 3D modeling for molding. Photocurable resin compositions are typically used in modeling, but the stronger a resin composition is, the more brittle it tends to become. On the other hand, attempts to impart toughness (i.e., flexibility) to a resin composition result in a flexible molecular structure that allows for moisture penetration, leading to not only a decrease in strength but also the significant problem of photopolymerization initiator degradation products leaching. In particular, dental materials using materials for stereolithography require the incorporation of large amounts of photopolymerization initiator due to the extremely short light exposure time compared to dental materials not designed for stereolithography. Consequently, the large amount of photopolymerization initiator can sometimes cause yellowing. The problems of elution from the cured product and color tone such as discoloration and yellowing are particularly important, and it has been difficult to fully satisfy these properties, including toughness and water resistance.

[0012] Against this background, Patent Document 1, for example, discloses a photopolymerizable resin composition containing a hydrogen abstraction photopolymerization initiator having an ethylenically unsaturated group, as a technology for obtaining a cured product that is excellent in mechanical properties and transparency, does not bleed out, and is highly safe.

[0013] International Publication No. 2023 / 074620

[0014] However, the photopolymerization initiator described in Patent Document 1 is difficult to obtain, and there are concerns about storage stability because it contains a polymerizable group. Furthermore, Patent Document 1 does not describe the strength and toughness of the cured product of the photopolymerizable resin composition, and the inventors have conducted research and found that there is room for improvement.

[0015] Therefore, an object of the present invention is to provide a dental polymerizable composition that is excellent in toughness and water resistance and produces little eluate, and a stereolithography material comprising the dental polymerizable composition.

[0016] The present invention encompasses the following inventions. [1] A dental polymerizable composition comprising a polyfunctional (meth)acrylic polymerizable compound (A) and a photopolymerization initiator (B) that does not contain a phosphine oxide skeleton. [2] The dental polymerizable composition according to [1], wherein the photopolymerization initiator (B) that does not contain a phosphine oxide skeleton contains a Norrish II type photopolymerization initiator. [3] The dental polymerizable composition according to [1] or [2], wherein the polyfunctional (meth)acrylic polymerizable compound (A) contains a polyfunctional (meth)acrylic polymerizable compound (A)-I having a molecular weight of less than 1,000 and / or a polyfunctional (meth)acrylic polymerizable compound (A)-II having a molecular weight of 1,000 or more. [4] The dental polymerizable composition according to [3], wherein the polyfunctional (meth)acrylic polymerizable compound (A) contains a polyfunctional urethane-modified (meth)acrylic polymerizable compound (A)-I-1 containing a urethane bond and a molecular weight of less than 1,000, and / or a polyfunctional urethane-modified (meth)acrylic polymerizable compound (A)-II-1 containing a urethane bond and a molecular weight of 1,000 or more. [5] The dental polymerizable composition according to [4], wherein the polyfunctional (meth)acrylic polymerizable compound (A)-I-1 contains a (meth)acrylate that does not contain a polymer structure in one molecule. [6] The dental polymerizable composition according to [4] or [5], wherein the polyfunctional urethane-modified (meth)acrylic polymerizable compound (A)-II-1 contains a (meth)acrylate that contains, in one molecule, at least one structure selected from the group consisting of polyester, polycarbonate, polyurethane, polyether, polyconjugated diene, and hydrogenated polyconjugated diene. [7] The dental polymerizable composition according to any one of [4] to [6], wherein the polyfunctional urethane-modified (meth)acrylic polymerizable compound (A)-II-1 contains a (meth)acrylate containing at least one polyol moiety selected from the group consisting of polyesters, polycarbonates, polyurethanes, polyethers, polyconjugated dienes, and hydrogenated polyconjugated dienes, each molecule of which has a structure derived from an aliphatic chain diol unit having 4 to 18 carbon atoms and a branched structure.[8] The dental polymerizable composition according to any one of [1] to [7], wherein the photopolymerization initiator (B) not containing a phosphine oxide skeleton contains at least one selected from the group consisting of α-aminoketone compounds, oxime ester compounds, and thioxanthones. [9] The dental polymerizable composition according to any one of [1] to [8], further containing a monofunctional (meth)acrylic polymerizable compound (C).

[10] The dental polymerizable composition according to [9], wherein the monofunctional (meth)acrylic polymerizable compound (C) contains a monofunctional (meth)acrylic polymerizable compound (C)-I containing a cyclic structure.

[11] The dental polymerizable composition according to

[10] , wherein the monofunctional (meth)acrylic polymerizable compound (C)-I contains one or more aromatic rings.

[12] The dental polymerizable composition according to

[10] or

[11] , wherein the monofunctional (meth)acrylic polymerizable compound (C)-I contains multiple aromatic rings.

[13] A material for stereolithography, comprising the dental polymerizable composition according to any one of [1] to

[12] .

[14] A denture base material, comprising a cured product of the stereolithography material according to

[13] .

[15] A dental occlusal splint, comprising a cured product of the stereolithography material according to

[13] .

[16] A material for treating sleep disorders, comprising a cured product of the stereolithography material according to

[13] .

[17] A method for producing a three-dimensional object by a stereolithography method using the dental polymerizable composition according to any one of [1] to

[12] .

[0017] The dental polymerizable composition of the present invention has excellent toughness and water resistance in a cured product, and produces little eluate. Therefore, the dental polymerizable composition of the present invention is suitable for use as a stereolithography material for dental applications, particularly as a dental material (dental occlusal splint and denture base material), and is also suitable as a material for use in a treatment device for sleep apnea syndrome. Furthermore, the dental polymerizable composition of the present invention also has excellent mechanical strength in a cured product.

[0018] The present invention will be described in detail below using embodiments. In this specification, the upper and lower limits of numerical ranges (such as the content of each component, values ​​calculated from each component, and physical properties) can be combined as appropriate. For example, in this specification, the lower and upper limits of numerical ranges described in stages can be independently combined. For example, a description of the same item as "preferably 0.2 to 8.0 mass%, more preferably 0.5 to 5.0 mass%" can be combined with the "preferable lower limit (0.2 mass%)" and the "more preferable upper limit (5.0 mass%)" to yield "0.2 to 5.0 mass%" or 0.5 to 8.0 mass%. Furthermore, regarding a numerical range, for example, based on the description "more preferably 12 to 28 mass%, and even more preferably 12.5 to 25 mass%, " the upper limit can be specified without any particular upper limit, and only the lower limit can be specified as "12 mass% or more" or "12.5 mass% or more". Similarly, the lower limit can be specified without any particular lower limit, and only the upper limit can be specified as "28 mass% or less" or "25 mass% or less". Unless otherwise specified, when a numerical range is simply described as "30 to 70", it represents a range of 30 to 70. Furthermore, for example, when the numerical range is "25 mass% or more and 75 mass% or less", the boundary of the numerical range can be selected from any of "more than 25 mass%, "25 mass% or more", "75 mass% or less", and "less than 75 mass%". As above, for example, from the description "more preferably 0.05 parts by mass or more, even more preferably 0.1 parts by mass or more" and the description "more preferably 15 parts by mass or less, even more preferably 10 parts by mass or less" for the same item, the "more preferable lower limit (0.05 parts by mass or more)" and the "more preferable upper limit (10 parts by mass or less)" can be combined to form "0.05 parts by mass or more and 10 parts by mass or less." Also, as above, only the lower limit can be specified as "0.05 parts by mass or more" or "0.1 parts by mass or more," and similarly, only the upper limit can be specified as "15 parts by mass or less" or "10 parts by mass or less." The numerical ranges described above are merely examples of % by mass and parts by mass, and the same applies to molecular weight, etc.

[0019] In this specification, the term "polymerizable compound" refers to a polymerizable compound that is polymerized by a photopolymerization initiator, as described below. In this specification, the term "(meth)acrylic" encompasses both "methacrylic" and "acrylic." The same applies to similar terms such as "(meth)acrylate," "(meth)acrylic acid ester," "(meth)acrylamide," and "(meth)acryloyloxy." In this specification, the term "(meth)acrylic polymerizable compound" encompasses both a polymerizable compound having a "(meth)acryloxy group" as a polymerizable group and a polymerizable compound having a "(meth)acrylamide group" as a polymerizable group. In this specification, the term "multifunctional" refers to a compound having more than one polymerizable group. In this specification, the term "molecular weight" refers to a single value calculated from atomic weights when an oligomeric or polymeric structure is not included. In this specification, the term "molecular weight" refers to a weight average molecular weight, unless otherwise specified, when an oligomeric or polymeric structure is included, and refers to a weight average molecular weight calculated in terms of polystyrene equivalents by gel permeation chromatography (GPC).

[0020] The dental polymerizable composition of the present invention contains a polyfunctional (meth)acrylic polymerizable compound (A) and a photopolymerization initiator (B) that does not contain a phosphine oxide skeleton.

[0021] [Polyfunctional (meth)acrylic polymerizable compound (A)] In the dental polymerizable composition of the present invention, the polyfunctional (meth)acrylic polymerizable compound (A) is used to impart curability to the dental polymerizable composition by combining it with the photopolymerization initiator (B), thereby imparting strength and toughness to the cured product. The polyfunctional (meth)acrylic polymerizable compound (A) preferably contains a polyfunctional (meth)acrylic polymerizable compound (A)-I having a molecular weight of less than 1,000 (also simply referred to as the "polyfunctional (meth)acrylic polymerizable compound (A)-I") and / or a polyfunctional (meth)acrylic polymerizable compound (A)-II having a molecular weight of 1,000 or more (also simply referred to as the "polyfunctional (meth)acrylic polymerizable compound (A)-II"). The polyfunctional (meth)acrylic polymerizable compound (A)-I is used to impart particular strength to the cured product of the dental polymerizable composition. On the other hand, the polyfunctional (meth)acrylic polymerizable compound (A)-II is used to impart particularly toughness to the cured product of the dental polymerizable composition.

[0022] From the viewpoint of excellent water resistance, the polyfunctional (meth)acrylic polymerizable compound (A)-I having a molecular weight of less than 1000 preferably does not contain a polymer structure in one molecule, and more preferably is a (meth)acrylate that does not contain a polymer structure in one molecule. When a polymer structure is not contained in one molecule, the content of repeating units of polar functional groups per molecule becomes small, and therefore water resistance tends to be excellent. Examples of polymer structures include polyester, polycarbonate, polyurethane, polyether, polyamide, polyimide, polyarylate, polyacrylate, etc.

[0023] Examples of the polyfunctional (meth)acrylic polymerizable compound (A)-I include a polyfunctional urethane-modified (meth)acrylic polymerizable compound (A)-I-1 containing a urethane bond (hereinafter also simply referred to as "polyfunctional urethane-modified (meth)acrylic polymerizable compound (A)-I-1") and a polyfunctional (meth)acrylic polymerizable compound (A)-I-2 not containing a urethane bond (hereinafter also simply referred to as "polyfunctional (meth)acrylic polymerizable compound (A)-I-2"). From the viewpoint of excellent toughness of the cured product and the fact that the urethane bond also functions as a hydrogen-donor structure, further improving curability and reducing leachable matter from the cured product, it is preferable to contain the polyfunctional urethane-modified (meth)acrylic polymerizable compound (A)-I-1, and it is more preferable that the polyfunctional urethane-modified (meth)acrylic polymerizable compound (A)-I-1 is a (meth)acrylate not containing a polymer structure in one molecule. In a preferred embodiment, from the viewpoint of providing a cured product with excellent toughness and water resistance, and from the viewpoint of further improving curability and reducing leachable materials from the cured product due to the urethane bond also functioning as a hydrogen-donating structure, the dental polymerizable composition includes a polyfunctional (meth)acrylic polymerizable compound (A)-I containing a polyfunctional urethane-modified (meth)acrylic polymerizable compound (A)-I-1, and the polyfunctional urethane-modified (meth)acrylic polymerizable compound (A)-I-1 being a (meth)acrylate that does not contain a polymer structure and a ring structure within one molecule. In this specification, examples of the ring structure include an aromatic ring, an alicyclic ring (a saturated or unsaturated carbon ring having no aromaticity), a heterocyclic ring, and the like. Examples of the alicyclic ring and the heterocyclic ring include, but are not limited to, a five-membered ring and a six-membered ring.

[0024] The polyfunctional urethane-modified (meth)acrylic polymerizable compound (A)-I-1 can be easily synthesized, for example, by addition reaction of a compound having an isocyanate group containing an alkylene skeleton or a phenylene skeleton with a (meth)acrylic compound having a hydroxyl group (—OH). Examples of the compound having an isocyanate group and the (meth)acrylic compound having a hydroxyl group (—OH) include the same compounds as those exemplified in the production of the polyfunctional urethane-modified (meth)acrylic polymerizable compound (A)-II-1 described below. The addition reaction can be carried out using known methods and conditions, and is not particularly limited.

[0025] Examples of the polyfunctional (meth)acrylic polymerizable compound (A)-I-1 include bifunctional (meth)acrylic polymerizable compounds and trifunctional or higher functional (meth)acrylic polymerizable compounds, but from the viewpoint of the toughness of the cured product, bifunctional (meth)acrylic polymerizable compounds are preferred. In a preferred embodiment (X-1), from the viewpoint of the excellent toughness and water resistance of the cured product and the fact that the urethane bond also functions as a hydrogen-donating structure, thereby further improving the curability and reducing the amount of elution from the cured product, the polyfunctional (meth)acrylic polymerizable compound (A)-I contains a polyfunctional urethane-modified (meth)acrylic polymerizable compound (A)-I-1, and the polyfunctional urethane-modified (meth)acrylic polymerizable compound (A)-I-1 is a di(meth)acrylate that does not contain a polymer structure and a ring structure in one molecule.

[0023] Another preferred embodiment (X-2) of the dental polymerizable composition includes a polyfunctional (meth)acrylic polymerizable compound (A) containing a urethane bond and a polyfunctional urethane-modified (meth)acrylic polymerizable compound (A)-I-1 having a molecular weight of less than 1,000, and a polyfunctional urethane-modified (meth)acrylic polymerizable compound (A)-II-1 having a molecular weight of 1,000 or more, and the polyfunctional urethane-modified (meth)acrylic polymerizable compound (A)-I-1 is a di(meth)acrylate that does not contain a polymer structure and a ring structure in one molecule.

[0024] Another preferred embodiment (X-3) of the dental polymerizable composition includes a polyfunctional urethane-modified (meth)acrylic polymerizable compound (A)-II-1 having a molecular weight of 1,000 or more and a urethane bond in the dental polymerizable composition of the above-mentioned embodiment (X-2), wherein the polyfunctional urethane-modified (meth)acrylic polymerizable compound (A)-II-1 does not contain a ring structure. In the above-described embodiment (X-2) and embodiment (X-3), the polyfunctional urethane-modified (meth)acrylic polymerizable compound (A)-I-1 containing a urethane bond and having a molecular weight of less than 1000 and the polyfunctional urethane-modified (meth)acrylic polymerizable compound (A)-II-1 containing a urethane bond and having a molecular weight of 1000 or more act together with other components, and from the viewpoint of providing a cured product with excellent toughness and water resistance, and the urethane bond also acting as a hydrogen-donor structure, the curability is further improved and the amount of elution from the cured product can be reduced.In any of the above-described embodiments, the ring structure may be any of those described above.

[0026] Examples of the polyfunctional urethane-modified (meth)acrylic polymerizable compound (A)-I-1 include 2,2,4-trimethylhexamethylenebis(2-carbamoyloxyethyl)dimethacrylate (commonly known as UDMA), 2,4-tolylenebis(2-carbamoyloxyethyl)di(meth)acrylate, N,N-(2,2,4-trimethylhexamethylene)bis[2-(aminocarboxy)propane-1,3-diol]tetra(meth)acrylate, bishydroxyethyl methacrylate-isophorone diurethane, 2,4-tolylenebis(2 Examples of the polyfunctional (meth)acrylic polymerizable compound (A)-I include polyfunctional urethane-modified (meth)acrylate of (meth-carbamoyloxyethyl) dimethacrylate, phenyl glycidyl ether (meth)acrylate hexamethylene diisocyanate urethane prepolymer, pentaerythritol tri(meth)acrylate hexamethylene diisocyanate urethane prepolymer, pentaerythritol tri(meth)acrylate toluene diisocyanate urethane prepolymer, and pentaerythritol tri(meth)acrylate isophorone diisocyanate urethane prepolymer. One type of polyfunctional (meth)acrylic polymerizable compound (A)-I may be used alone, or two or more types may be used in combination. Among these, from the viewpoint of strength and toughness of the shaped product, 2,2,4-trimethylhexamethylenebis(2-carbamoyloxyethyl)dimethacrylate and phenylglycidyl ether acrylate hexamethylene diisocyanate urethane prepolymer are preferred, and 2,2,4-trimethylhexamethylenebis(2-carbamoyloxyethyl)dimethacrylate is more preferred.

[0027] The content of the polyfunctional (meth)acrylic polymerizable compound (A)-I is preferably 10 to 70% by mass, more preferably 20 to 65% by mass, even more preferably 25 to 60% by mass, and particularly preferably 30 to 55% by mass, based on 100% by mass of the total amount of the polymerizable compounds, from the viewpoint of achieving superior strength, toughness, and water resistance of the shaped object when combined with other components. In another preferred embodiment, the content of the polyfunctional (meth)acrylic polymerizable compound (A)-I is preferably 20 to 80% by mass, more preferably 30 to 75% by mass, even more preferably 35 to 75% by mass, and particularly preferably 40 to 70% by mass, based on 100% by mass of the total amount of the polyfunctional (meth)acrylic polymerizable compound (A), from the viewpoint of achieving superior strength of the shaped object. In another preferred embodiment, the content of the polyfunctional (meth)acrylic polymerizable compound (A)-I is preferably 10 to 70 mass%, more preferably 20 to 65 mass%, even more preferably 25 to 60 mass%, and particularly preferably 30 to 55 mass%, based on the total amount (100 mass%) of the dental polymerizable composition, from the viewpoint of achieving superior strength, toughness, and water resistance of a shaped object when combined with other components. In any of the above-mentioned embodiments, the content of the polyfunctional (meth)acrylic polymerizable compound (A)-I can be read as the content of the polyfunctional urethane-modified (meth)acrylic polymerizable compound (A)-I-1, from the viewpoint of further reducing leachable substances from the cured product.

[0028] In another preferred embodiment, the content of the polyfunctional urethane-modified (meth)acrylic polymerizable compound (A)-I-1 in the polyfunctional (meth)acrylic polymerizable compound (A)-I is preferably 20% by mass or more, more preferably 40% by mass or more, even more preferably 60% by mass or more, and particularly preferably 80% by mass or more, based on the viewpoint of superior strength of the shaped object, the urethane bond also acting as a hydrogen donor structure, further improving curability, and reducing elution from the cured product, relative to the total amount of the polyfunctional (meth)acrylic polymerizable compound (A)-I (100% by mass).

[0029] Examples of the polyfunctional (meth)acrylic polymerizable compound (A)-I-2 include bifunctional (meth)acrylic polymerizable compounds and trifunctional or higher functional (meth)acrylic polymerizable compounds. From the viewpoint of toughness of the cured product, bifunctional (meth)acrylic polymerizable compounds are preferred.

[0030] Examples of the polyfunctional (meth)acrylic polymerizable compound (A)-I-2 include 2,2-bis((meth)acryloyloxyphenyl)propane, 2,2-bis(4-(meth)acryloyloxyethoxyphenyl)propane, 2,2-bis(4-(meth)acryloyloxydiethoxyphenyl)propane, 2,2-bis(4-(meth)acryloyloxypropoxyphenyl)propane, 2,2-bis[4-(2-hydroxy-3-methacryloyloxypropoxy)phenyl]propane (commonly known as "Bis-GMA") ... -3-acryloyloxypropoxy)phenyl]propane, 2,2-bis(4-(meth)acryloyloxytetraethoxyphenyl)propane, 2,2-bis(4-(meth)acryloyloxypentaethoxyphenyl)propane, 2-(4-(meth)acryloyloxydiethoxyphenyl)-2-(4-(meth)acryloyloxyethoxyphenyl)propane, 2-(4-(meth)acryloyloxydiethoxyphenyl)-2-(4-(meth)acryloyloxytriethoxyphenyl)propane, 2-(4-(meth)acryloyloxydiphenyl)-2-(4-(meth)acryloyloxytriethoxyphenyl)propane, 2,2-bis(4-(meth)acryloyloxyisopropoxyphenyl)propane, 2,2-bis(4-(meth)acryloyloxypolyethoxyphenyl)propane (for example, average number of moles of ethoxy groups added: 2.6), 1,4-bis(2-(meth)acryloyloxyethyl)pyromellitate, glycerol di(meth)acrylate, ethylene glycol di(meth)acrylate, diethylene glycol di(meth)acrylate, 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)acrylate, 1,10-decanediol di(meth)acrylate, 1,Examples include 2-bis(3-methacryloyloxy-2-hydroxypropoxy)ethane and tricyclodecane dimethanol di(meth)acrylate.

[0031] Examples of the tri- or higher functional polymerizable compound include trimethylolpropane tri(meth)acrylate, trimethylolethane tri(meth)acrylate, trimethylolmethane tri(meth)acrylate, pentaerythritol tri(meth)acrylate, pentaerythritol tetra(meth)acrylate, dipentaerythritol penta(meth)acrylate, and 1,7-di(meth)acryloyloxy-2,2,6,6-tetra(meth)acryloyloxymethyl-4-oxaheptane.

[0032] The molecular weight of the polyfunctional urethane-modified (meth)acrylic polymerizable compound (A)-I must be less than 1,000, and from the viewpoint of strength and toughness, it is preferably 250 to 900, more preferably 300 to 800.

[0033] The polyfunctional (meth)acrylic polymerizable compound (A)-II having a molecular weight of 1,000 or more (hereinafter, also simply referred to as "polyfunctional (meth)acrylic polymerizable compound (A)-II") is used in the dental polymerizable composition of the present invention to impart toughness to the cured product.

[0034] The polyfunctional (meth)acrylic polymerizable compound (A)-II is classified into polyfunctional (meth)acrylic polymerizable compounds containing an oligomer or polymer structure in one molecule and polyfunctional (meth)acrylic polymerizable compounds not containing an oligomer or polymer structure in one molecule. From the viewpoint of achieving excellent strength and toughness of a shaped product when combined with other components, it is preferable to contain a polyfunctional (meth)acrylic polymerizable compound containing an oligomer or polymer structure in one molecule. Furthermore, examples of the polyfunctional (meth)acrylic polymerizable compound (A)-II include a polyfunctional urethane-modified (meth)acrylic polymerizable compound (A)-II-1 containing a urethane bond (hereinafter also simply referred to as "polyfunctional urethane-modified (meth)acrylic polymerizable compound (A)-II-1") and a polyfunctional (meth)acrylic polymerizable compound (A)-II-2 containing no urethane bond. From the viewpoint of excellent toughness of the cured product and the fact that the urethane bond also functions as a hydrogen-donor structure, thereby further improving curability and reducing leachable matter from the cured product, it is preferable to contain the polyfunctional urethane-modified (meth)acrylic polymerizable compound (A)-II-1, and it is more preferable to contain a polyfunctional urethane-modified (meth)acrylic polymerizable compound (A)-II-1 containing an oligomer or polymer structure in one molecule. In a preferred embodiment, from the viewpoint of excellent toughness of the cured product, and from the viewpoint of further improving curability and reducing elution from the cured product due to the urethane bond also functioning as a hydrogen-donating structure, a dental polymerizable composition containing the polyfunctional urethane-substituted (meth)acrylic polymerizable compound (A)-I-1 and / or the polyfunctional urethane-substituted (meth)acrylic polymerizable compound (A)-II-1 is mentioned.

[0035] The polyfunctional urethane-modified (meth)acrylic polymerizable compound (A)-II-1 containing an oligomer or polymer structure in one molecule can be easily synthesized by addition reaction of a polyol having a polymer skeleton such as a polymer structure of polyester, polycarbonate, polyurethane, polyether, polydiene, or hydrogenated polydiene, a compound having an isocyanate group (-NCO), and a (meth)acrylic compound having a hydroxyl group (-OH). Alternatively, the compound can be easily synthesized by ring-opening addition reaction of a lactone or alkylene oxide with a (meth)acrylic compound having a hydroxyl group, followed by addition reaction of the resulting compound having a hydroxyl group at one end with a compound having an isocyanate group.

[0036] The polyfunctional urethane-modified (meth)acrylic polymerizable compound (A)-II-1 is preferably a (meth)acrylate containing, in one molecule, at least one structure selected from the group consisting of polyester, polycarbonate, polyurethane, polyether, polyconjugated diene, and hydrogenated polyconjugated diene.

[0037] In the above structure, examples of the polyester include copolymers of dicarboxylic acids (e.g., aromatic dicarboxylic acids such as phthalic acid and isophthalic acid; unsaturated aliphatic dicarboxylic acids such as maleic acid) and aliphatic diols having 2 to 18 carbon atoms, copolymers of dicarboxylic acids (e.g., saturated aliphatic dicarboxylic acids such as adipic acid and sebacic acid) and aliphatic diols having 2 to 18 carbon atoms, β-propiolactone polymers, γ-butyrolactone polymers, δ-valerolactone polymers, ε-caprolactone polymers, and copolymers thereof, and preferred are copolymers of dicarboxylic acids (preferably aromatic dicarboxylic acids, unsaturated aliphatic dicarboxylic acids) and aliphatic diols having 2 to 12 carbon atoms, and copolymers of dicarboxylic acids (preferably saturated aliphatic dicarboxylic acids) and aliphatic glycols having 2 to 12 carbon atoms. Examples of polycarbonates include polycarbonates derived from aliphatic diols having 2 to 18 carbon atoms, polycarbonates derived from bisphenol A, and polycarbonates derived from aliphatic diols having 2 to 18 carbon atoms and bisphenol A, with polycarbonates derived from aliphatic diols having 2 to 12 carbon atoms, polycarbonates derived from bisphenol A, and polycarbonates derived from aliphatic diols having 2 to 12 carbon atoms and bisphenol A being preferred. Examples of polyurethanes include polymers of aliphatic diols having 2 to 18 carbon atoms and diisocyanates having 1 to 18 carbon atoms, with polymers of aliphatic diols having 2 to 12 carbon atoms and diisocyanates having 1 to 12 carbon atoms being preferred. Examples of polyethers include polyethylene glycol, polypropylene glycol, polybutylene glycol, and poly(1-methylbutylene glycol). Examples of polyconjugated dienes and hydrogenated polyconjugated dienes include 1,4-polybutadiene, 1,2-polybutadiene, polyisoprene, poly(butadiene-isoprene), poly(butadiene-styrene), poly(isoprene-styrene), polyfarnesene, and hydrogenated products thereof. Among these, polyester structures are preferred because of their excellent toughness and water resistance.

[0038] In view of superior toughness and water resistance, the polyfunctional urethane-modified (meth)acrylic polymerizable compound (A)-II-1 is preferably a (meth)acrylate containing, in one molecule, at least one polyol moiety selected from the group consisting of polyesters, polycarbonates, polyurethanes, polyethers, polyconjugated dienes, and hydrogenated polyconjugated dienes, each having a structure derived from a branched aliphatic chain diol unit having 4 to 18 carbon atoms. Examples of the polyester include copolymers having a structure derived from a branched aliphatic chain diol unit having 4 to 18 carbon atoms and a structure derived from an unbranched aliphatic chain dicarboxylic acid and / or aromatic dicarboxylic acid unit having 4 to 18 carbon atoms. Examples of the polycarbonate include copolymers having a structure derived from a branched aliphatic chain diol unit having 4 to 18 carbon atoms and a structure derived from an unbranched aliphatic chain diol unit having 4 to 18 carbon atoms. Examples of the polyurethane include a polycondensate of a structure derived from a branched aliphatic chain diol unit having 4 to 18 carbon atoms and a diisocyanate compound. Examples of the polyether include a polyether having a structure derived from a branched aliphatic chain diol unit having 4 to 18 carbon atoms, and a polyether having a structure derived from a non-branched aliphatic chain diol unit having 4 to 18 carbon atoms. Examples of the polyconjugated diene include a homopolymer or copolymer of a conjugated diene monomer. Examples of the conjugated diene monomer include 1,3-butadiene, isoprene, 2,3-dimethyl-1,3-butadiene, 1,3-pentadiene, and 1,3-hexadiene. Examples of the hydrogenated polyconjugated diene include hydrogenated polybutadiene, hydrogenated polyisoprene, and hydrogenated polyisobutylene.Among these, in terms of excellent toughness and water resistance, it is preferable that the polymer skeleton contains at least one structure selected from the group consisting of polyesters, polycarbonates, polyethers, and hydrogenated polyconjugated dienes, it is more preferable that the polymer skeleton contains at least one structure selected from the group consisting of polyesters and polycarbonates, and it is even more preferable that the polymer skeleton contains at least one structure selected from the group consisting of polyesters.

[0039] Examples of diols constituting the aliphatic chain diol unit having 4 to 18 carbon atoms and a branched structure include 2-methyl-1,3-propanediol, 2,2-diethyl-1,3-propanediol, 1,3-butanediol, 2-methyl-1,4-butanediol, neopentyl glycol, 3-methyl-1,5-pentanediol, 2-methyl-1,8-octanediol, 2,7-dimethyl-1,8-octanediol, 2-methyl-1,9-nonanediol, 2,8-dimethyl-1,9-nonanediol, 2-methyl-1,10-decanediol, 2,9-dimethyl-1,10-decanediol, 2-methyl-1,1 Examples of the diol include 1-undecanediol, 2,10-dimethyl-1,11-undecanediol, 2-methyl-1,12-dodecanediol, 2,11-dimethyl-1,12-dodecanediol, 2-methyl-1,13-tridecanediol, 2,12-dimethyl-1,13-tridecanediol, 2-methyl-1,14-tetradecanediol, 2,13-dimethyl-1,14-tetradecanediol, 2-methyl-1,15-pentadecanediol, 2,14-dimethyl-1,15-pentadecanediol, 2-methyl-1,16-hexadecanediol, and 2,15-dimethyl-1,16-hexadecanediol. Among these, from the viewpoint of providing a dental polymerizable composition with excellent curability and low viscosity, it is preferable to use, as the polyol, an aliphatic diol having 5 to 12 carbon atoms and a methyl group in the side chain, such as 2-methyl-1,4-butanediol, 3-methyl-1,5-pentanediol, 2-methyl-1,8-octanediol, 2,7-dimethyl-1,8-octanediol, 2-methyl-1,9-nonanediol, or 2,8-dimethyl-1,9-nonanediol, more preferably 2-methyl-1,4-butanediol, 3-methyl-1,5-pentanediol, 2-methyl-1,8-octanediol, or 2,7-dimethyl-1,8-octanediol, and even more preferably 3-methyl-1,5-pentanediol or 2-methyl-1,8-octanediol.

[0040] Examples of compounds 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), and adamantane diisocyanate (ADI).

[0041] Examples of the (meth)acrylic 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, and 2-hydroxy-3-acryloyloxypropyl (meth)acrylate. hydroxy(meth)acrylate compounds such as dipentaerythritol, 2,2-bis[4-(2-hydroxy-3-(meth)acryloyloxypropoxy)phenyl]propane, 1,2-bis[3-(meth)acryloyloxy-2-hydroxypropoxy]ethane, pentaerythritol tri(meth)acrylate, and dipentaerythritol tri- or tetra(meth)acrylate; and hydroxy(meth)acrylamide compounds such as N-hydroxyethyl(meth)acrylamide and N,N-bis(2-hydroxyethyl)(meth)acrylamide. When the desired polyfunctional urethane-type (meth)acrylic polymerizable compound (A)-II-1 is a (meth)acrylate compound, it can be produced by selecting a hydroxy(meth)acrylate compound.

[0042] The addition reaction between a compound having an isocyanate group and a (meth)acrylic compound having a hydroxyl group can be carried out using known methods and conditions, and is not particularly limited.

[0043] Examples of the polyfunctional urethane-modified (meth)acrylic polymerizable compound (A)-II-1 that does not contain a polymer structure in one molecule include dipentaerythritol penta(meth)acrylate hexamethylene diisocyanate urethane prepolymer.

[0044] The molecular weight of the polyfunctional urethane-modified (meth)acrylic polymerizable compound (A)-II-1 must be 1,000 or more, and from the viewpoint of strength and toughness, it is preferably 1,500 to 5,000, more preferably 2,000 to 3,000.

[0045] Examples of the polyfunctional urethane-modified (meth)acrylic polymerizable compound (A)-II include bifunctional (meth)acrylic polymerizable compounds and trifunctional or higher functional (meth)acrylic polymerizable compounds.

[0046] In a preferred embodiment, the content of the polyfunctional urethanized (meth)acrylic polymerizable compound (A)-II-1 is preferably 1 to 70% by mass, more preferably 5 to 60% by mass, even more preferably 10 to 50% by mass, and particularly preferably 20 to 40% by mass, based on 100% by mass of the total amount of the polymerizable compounds, from the viewpoints that when combined with other components, the shaped object will have better strength, toughness, and water resistance, and that the urethane bond also functions as a hydrogen-donor structure, further improving curability and reducing elution from the cured object. In another preferred embodiment, the content of the polyfunctional urethane-type (meth)acrylic polymerizable compound (A)-II-1 is preferably 10 to 75% by mass, more preferably 15 to 70% by mass, even more preferably 20 to 65% by mass, and particularly preferably 25 to 60% by mass, based on 100% by mass of the total amount of the polyfunctional (meth)acrylic polymerizable compound (A), from the viewpoints that when the compound is combined with other components, the strength, toughness, and water resistance of a shaped object will be superior, and that the urethane bond also functions as a hydrogen-donor structure, thereby further improving curability and reducing elution from the cured product. In another preferred embodiment, the content of the polyfunctional urethanized (meth)acrylic polymerizable compound (A)-II-1 is preferably 1 to 70% by mass, more preferably 5 to 60% by mass, even more preferably 10 to 50% by mass, and particularly preferably 20 to 40% by mass, based on 100% by mass of the total amount of the dental polymerizable composition, from the viewpoints that when the compound is combined with other components, a shaped object will have better strength, toughness, and water resistance, and that the urethane bond also functions as a hydrogen-donor structure, thereby further improving curability and reducing elution from the cured product.

[0047] The content of the polyfunctional urethane-modified (meth)acrylic polymerizable compound (A)-II-1 is preferably 20% by mass or more, more preferably 40% by mass or more, even more preferably 60% by mass or more, and particularly preferably 80% by mass or more, based on the viewpoint that when combined with other components, the strength, toughness, and water resistance of the cured product are superior, and the urethane bond also functions as a hydrogen-donating structure, further improving curability and reducing elution from the cured product. Furthermore, the content of the polyfunctional urethane-modified (meth)acrylic polymerizable compound (A)-II-1 in the polyfunctional (meth)acrylic polymerizable compound (A)-II may be 100% by mass.

[0048] Examples of the polyfunctional (meth)acrylic polymerizable compound (A)-II-2 that does not contain a urethane bond include bifunctional (meth)acrylic polymerizable compounds and trifunctional or higher functional (meth)acrylic polymerizable compounds.

[0049] Examples of the polyfunctional (meth)acrylic polymerizable compound (A)-II-2 not containing a urethane bond include 2,2-bis(4-(meth)acryloyloxypolyethoxyphenyl)propane (for example, average number of moles of ethoxy groups added: 25 or more), polyethylene glycol di(meth)acrylate, and the like.

[0050] The content of the polyfunctional (meth)acrylic polymerizable compound (A)-II in the dental polymerizable composition of the present invention is preferably 1 to 80% by mass, more preferably 5 to 70% by mass, even more preferably 10 to 60% by mass, and particularly preferably 20 to 50% by mass, based on 100% by mass of the total amount of polymerizable compounds, in order to provide a cured product having excellent strength, toughness, and water resistance when combined with other components. The polyfunctional (meth)acrylic polymerizable compound (A)-II may be used alone, or two or more types may be used in combination. Furthermore, the content of the polyfunctional (meth)acrylic polymerizable compound (A)-II in the dental polymerizable composition of the present invention is preferably 10 to 60% by mass, more preferably 15 to 65% by mass, even more preferably 20 to 50% by mass, and particularly preferably 25 to 45% by mass, based on 100% by mass of the total amount of the dental polymerizable composition, in order to provide a cured product having excellent strength, toughness, and water resistance when combined with other components.

[0051] In the dental polymerizable composition of the present invention, the mass ratio of the polyfunctional (meth)acrylic polymerizable compound (A)-I to the polyfunctional (meth)acrylic polymerizable compound (A)-II is preferably (A)-I:(A)-II=5:95 to 95:5, more preferably 10:90 to 90:10, and even more preferably 20:80 to 80:20, in terms of achieving better strength, toughness, and water resistance of the cured product.

[0052] The content of the polyfunctional (meth)acrylic polymerizable compound (A) in the dental polymerizable composition of the present invention is preferably 10 to 95% by mass, based on 100% by mass of the total amount of polymerizable compounds. From the viewpoint of achieving superior strength, toughness, water resistance, and impact resistance of a shaped object when combined with other components, the content is more preferably 20 to 92% by mass, even more preferably 30 to 90% by mass, and particularly preferably 40 to 85% by mass. The polyfunctional (meth)acrylic polymerizable compound (A) may be used alone, or two or more types may be used in combination. Furthermore, the content of the polyfunctional (meth)acrylic polymerizable compound (A) in the dental polymerizable composition of the present invention is preferably 10 to 95% by mass, more preferably 20 to 92% by mass, even more preferably 30 to 90% by mass, and particularly preferably 40 to 85% by mass, based on 100% by mass of the total amount of the dental polymerizable composition, from the viewpoint of achieving superior strength, toughness, and water resistance of a shaped object when combined with other components.

[0053] [Monofunctional (meth)acrylic polymerizable compound (C)] A preferred embodiment includes a dental polymerizable composition further containing a monofunctional (meth)acrylic polymerizable compound (C). The monofunctional (meth)acrylic polymerizable compound (C) is used in the dental polymerizable composition of the present invention to reduce the viscosity of the dental polymerizable composition and impart higher water resistance to the cured product. Examples of the monofunctional (meth)acrylic polymerizable compound (C) include a monofunctional (meth)acrylic polymerizable compound (C)-I containing a cyclic structure and a monofunctional (meth)acrylic polymerizable compound (C)-II not containing a cyclic structure. From the viewpoint of achieving superior curability of the dental polymerizable composition and water resistance of the cured product, the monofunctional (meth)acrylic polymerizable compound (C)-I containing a cyclic structure is preferred. Examples of the ring constituting the cyclic structure include an aromatic ring, an alicyclic ring, and a heterocyclic ring (e.g., a nitrogen-containing heterocyclic ring). The number of rings (e.g., aromatic rings) possessed by the monofunctional (meth)acrylic polymerizable compound (C)-I containing a cyclic structure is one or more, and preferably two or more (two or more). Examples of the monofunctional (meth)acrylic polymerizable compound (C)-I include (meth)acrylic acid ester compounds containing an aromatic ring, alicyclic (meth)acrylic acid ester compounds, nitrogen atom-containing cyclic (meth)acrylic acid ester compounds, and cyclic (meth)acrylamide compounds. Examples of the monofunctional (meth)acrylic polymerizable compound (C)-II not containing a cyclic structure include chain (meth)acrylic acid ester compounds. As the monofunctional (meth)acrylic polymerizable compound (C)-I containing a cyclic structure, from the viewpoints of the curability of the dental polymerizable composition and the water resistance of the cured product, preferred are (meth)acrylic acid ester compounds containing an aromatic ring and alicyclic (meth)acrylic acid ester compounds, from the viewpoint of being less likely to generate an odor, more preferred are (meth)acrylic acid ester compounds containing one or more aromatic rings, and from the viewpoints of being more excellent in the curability of the dental polymerizable composition and the water resistance of the cured product, still more preferred are (meth)acrylic acid ester compounds containing multiple aromatic rings.

[0054] Examples of the (meth)acrylic acid ester compound containing one aromatic ring include phenyl (meth)acrylate, benzyl (meth)acrylate, phenoxyethyl (meth)acrylate, phenoxybutyl (meth)acrylate, phenoxydiethylene glycol (meth)acrylate, phenoxypolyethylene glycol (meth)acrylate, 4-methylphenyl (meth)acrylate, 4-n-butylphenyl (meth)acrylate, 4-t-butylphenyl (meth)acrylate, 4-nonylphenyl (meth)acrylate, o-2-propenylphenyl (meth)acrylate, benzhydrol (meth)acrylate, and cumylphenol (meth)acrylate.

[0055] Examples of the (meth)acrylic acid ester compound containing two aromatic rings include o-phenylphenol (meth)acrylate, m-phenylphenol (meth)acrylate, p-phenylphenol (meth)acrylate, methoxylated o-phenylphenol (meth)acrylate, methoxylated m-phenylphenol (meth)acrylate, methoxylated p-phenylphenol (meth)acrylate, ethoxylated o-phenylphenol (meth)acrylate, ethoxylated m-phenylphenol (meth)acrylate, ethoxylated p-phenylphenol (meth)acrylate, propoxylated o-phenylphenol (meth)acrylate, propoxylated m-phenylphenol (meth)acrylate, propoxylated p-phenylphenol (meth)acrylate, butoxylated o-phenylphenol (meth)acrylate, butoxylated m-phenylphenol (meth)acrylate, butoxylated p-phenylphenol (meth)acrylate, o-phenoxybenzyl (meth)acrylate, m-phenoxybenzyl (meth)acrylate, p-phenoxybenzyl (meth)acrylate, 2-(o-phenoxyphenyl)ethyl (meth)acrylate, 2-(m-phenoxyphenyl)ethyl (meth)acrylate, 2-(p-phenoxyphenyl)ethyl (meth)acrylate, 3-(o-phenoxyphenyl)propyl (meth)acrylate, 3-(m-phenoxyphenyl)propyl (meth)acrylate, 3-(p-phenoxyphenyl)propyl

[0033] Examples of the acrylates include 4-(o-phenoxyphenyl)propyl (meth)acrylate, 4-(o-phenoxyphenyl)butyl (meth)acrylate, 4-(m-phenoxyphenyl)butyl (meth)acrylate, 4-(p-phenoxyphenyl)butyl (meth)acrylate, 4-biphenylyl (meth)acrylate, 1-naphthyl (meth)acrylate, 2-naphthyl (meth)acrylate, anthryl (meth)acrylate, fluorenyl (meth)acrylate, and fluorenylmethyl (meth)acrylate.

[0056] Examples of the alicyclic (meth)acrylic acid ester compound include 2-(1-adamantyl)propyl (meth)acrylate, 2-methyladamantyl-2-yl (meth)acrylate, 2-ethyladamantyl-2-yl (meth)acrylate, 2-n-propyladamantyl-2-yl (meth)acrylate, 2-isopropyladamantyl-2-yl (meth)acrylate, 1-(adamantan-1-yl)-1-methylethyl (meth)acrylate, 1-(adamantan-1-yl)-1-ethylethyl (meth)acrylate, 1-(adamantan-1-yl)-1-methylpropyl (meth)acrylate, and 1-(adamantan-1-yl)-1-ethylpropyl (meth)acrylate.

[0057] Examples of nitrogen atom-containing cyclic (meth)acrylic acid ester compounds include pentamethylpiperidinyl (meth)acrylate, tetramethylpiperidinyl (meth)acrylate, and 4-(pyrimidin-2-yl)piperazin-1-yl (meth)acrylate.

[0058] Examples of cyclic (meth)acrylamide compounds include N-(meth)acryloylmorpholine, N-(meth)acryloylpyrrolidine, N-(meth)acryloylpiperidine, N-(meth)acryloyl-2-methylpiperidine, and N-(meth)acryloyl-2,2,6,6-tetramethylpiperidine.

[0059] Among these, the monofunctional (meth)acrylic polymerizable compound (C) may be, from the viewpoint of excellent toughness and water resistance of the cured product of the dental polymerizable composition of the present invention, o-phenoxybenzyl acrylate, m-phenoxybenzyl acrylate, p-phenoxybenzyl acrylate, 2-(o-phenoxyphenyl)ethyl acrylate, 2-(m-phenoxyphenyl)ethyl acrylate, 2-(p-phenoxyphenyl)ethyl acrylate, 4-biphenylyl (meth)acrylate, 1-naphthyl (meth)acrylate, (meth)acrylic acid 2-Naphthyl is preferred, o-phenoxybenzyl acrylate, m-phenoxybenzyl acrylate, p-phenoxybenzyl acrylate, 2-(o-phenoxyphenyl)ethyl acrylate, 2-(m-phenoxyphenyl)ethyl acrylate, and 2-(p-phenoxyphenyl)ethyl acrylate are more preferred, and o-phenoxybenzyl acrylate, m-phenoxybenzyl acrylate, 2-(o-phenoxyphenyl)ethyl acrylate, and 2-(m-phenoxyphenyl)ethyl acrylate are even more preferred.

[0060] The content of the monofunctional (meth)acrylic polymerizable compound (C) in the dental polymerizable composition of the present invention is preferably 1.0 to 60% by mass, based on 100% by mass of the total amount of the polymerizable compounds, and is more preferably 5.0 to 50% by mass, even more preferably 10 to 40% by mass, and particularly preferably 15 to 30% by mass, from the viewpoints of being able to reduce the viscosity of the dental polymerizable composition without impairing the strength, toughness, and water resistance when combined with other components, and of achieving excellent toughness and water resistance of the cured product. The monofunctional (meth)acrylic polymerizable compound (C) may be used alone or in combination of two or more types.

[0061] In some embodiments, the content of the monofunctional (meth)acrylic polymerizable compound (C) is preferably 1.0 to 60% by mass, more preferably 5.0 to 50% by mass, even more preferably 10 to 40% by mass, and particularly preferably 15 to 30% by mass, relative to the total amount (100% by mass) of the dental polymerizable composition, from the viewpoint of achieving better toughness and water resistance of a cured product when combined with other components.

[0062] In another preferred embodiment, the mass ratio of the content of the monofunctional (meth)acrylic polymerizable compound (C) to the content of the polyfunctional (meth)acrylic polymerizable compound (A) is preferably (A) / (C) > 1. When the content of the polyfunctional (meth)acrylic polymerizable compound (A) is greater than the content of the monofunctional (meth)acrylic polymerizable compound (C), the strength, toughness, and water resistance of a shaped object are improved when combined with other components. In another preferred embodiment, the mass ratio of the content of the monofunctional (meth)acrylic polymerizable compound (C) to the total content of the polyfunctional (meth)acrylic polymerizable compound (A)-I and the polyfunctional (meth)acrylic polymerizable compound (A)-II is preferably ((A)-I + (A)-II) / (C) > 1. When the total content of the polyfunctional (meth)acrylic polymerizable compound (A)-I and the polyfunctional (meth)acrylic polymerizable compound (A)-II is greater than the content of the functional (meth)acrylic polymerizable compound (C), the strength, toughness, and water resistance of the cured product are superior. The mass ratio ((A)-I + (A)-II) / (C) is more preferably 1.2 or more, even more preferably 2 or more, and particularly preferably 3 or more. The mass ratio ((A)-I + (A)-II) / (C) is preferably 20 or less, more preferably 15 or less, even more preferably 10 or less, and particularly preferably 6 or less.

[0063] In one embodiment, the dental polymerizable composition of the present invention may be substantially free of (meth)acrylamide group-containing compounds as polymerizable compounds. "Substantially free of (meth)acrylamide group-containing compounds" means that the content of (meth)acrylamide group-containing compounds in the dental polymerizable composition is less than 1% by mass, preferably less than 0.1% by mass, more preferably less than 0.01% by mass, and even more preferably 0% by mass.

[0064] [Photopolymerization initiator (B) not containing a phosphine oxide skeleton] The photopolymerization initiator (B) not containing a phosphine oxide skeleton (also simply referred to as "photopolymerization initiator (B)") is used in the dental polymerizable composition of the present invention to impart the desired curability to the dental polymerizable composition, and must not contain a phosphine oxide skeleton from the viewpoint of preventing leachable substances from the cured product. The photopolymerization initiator (B) can be selected from polymerization initiators commonly used in industry, and preferably contains a Norrish II photopolymerization initiator from the viewpoint of preventing leachable substances from the cured product. In this specification, "Norrish II photopolymerization initiator" refers to a photopolymerization initiator capable of generating radicals by a hydrogen abstraction type radical mechanism.

[0065] Examples of the photopolymerization initiator (B) include α-aminoketone compounds, oxime ester compounds, thioxanthones or quaternary ammonium salts of thioxanthones, benzophenones, oxyphenylacetic acid ester compounds, α-diketones, ketals, coumarins, anthraquinones, benzoin alkyl ether compounds, etc. One type of photopolymerization initiator (B) may be used alone, or two or more types may be used in combination.

[0066] From the viewpoint of minimizing leachable materials from the cured product, these photopolymerization initiators (B) preferably contain at least one selected from the group consisting of α-aminoketone compounds, oxime ester compounds, thioxanthones, and quaternary ammonium salts of thioxanthones, more preferably at least one selected from the group consisting of α-aminoketone compounds, oxime ester compounds, and thioxanthones, and even more preferably contain α-aminoketone compounds and / or oxime ester compounds. The photopolymerization initiator (B) provides a dental polymerizable composition that exhibits excellent photocurability in the ultraviolet and visible light regions and sufficient photocurability using any light source, including lasers, halogen lamps, light-emitting diodes (LEDs), and xenon lamps, and can suppress leachable materials from the cured product due to decomposition of the photopolymerization initiator. Furthermore, in some embodiments, among the photopolymerization initiators (B), compounds having one or more aromatic rings are preferred, and compounds having two or more aromatic rings are more preferred, from the viewpoint of excellent curability. In another preferred embodiment, the dental polymerizable composition includes a photopolymerization initiator (B) that does not contain a polymerizable group at the end of its structure. Examples of the polymerizable group include a vinyl group, an allyl group, a (meth)acryloyl group, a vinylcycloalkyl group (e.g., a vinylcyclopropyl group), and the like.

[0067] Examples of the α-aminoketone compound used as the photopolymerization initiator include 2-benzyl-2-(dimethylamino)-4'-morpholinobutyrophenone, 2-methyl-1-[4-(methylthio)phenyl]-2-morpholinopropan-1-one, and the like.

[0068] Examples of the oxime ester compound used as the photopolymerization initiator include 1,2-octanedione, 1-[4-(phenylthio)phenyl]-, 2-(o-benzoyloxime) (also known as 1-[4-(phenylthio)phenyl]octane-1,2-dione = 2-(O-benzoyloxime)), ethanone, 1-[9-ethyl-6-(2-methylbenzoyl)-9H-carbazol-3-yl]-, 1-(o-acetyloxime) (also known as Irgacure OXE-02), and the like.

[0069] Examples of thioxanthones or quaternary ammonium salts of thioxanthones used as the photopolymerization initiator include thioxanthone, 2-chlorothioxanthone, 2-hydroxy-3-(9-oxo-9H-thioxanthen-4-yloxy)-N,N,N-trimethyl-1-propanaminium chloride, 2-hydroxy-3-(1-methyl-9-oxo-9H-thioxanthen-4-yloxy)-N,N,N-trimethyl-1-propanaminium chloride, 2-hydroxy-3-(9-oxo-9H-thioxanthen-2-yloxy)-N,N , N-trimethyl-propanaminium chloride, 2-hydroxy-3-(3,4-dimethyl-9-oxo-9H-thioxanthen-2-yloxy)-N,N,N-trimethyl-1-propanaminium chloride, 2-hydroxy-3-(3,4-dimethyl-9H-thioxanthen-2-yloxy)-N,N,N-trimethyl-1-propanaminium chloride, 2-hydroxy-3-(1,3,4-trimethyl-9-oxo-9H-thioxanthen-2-yloxy)-N,N,N-trimethyl-1-propanaminium chloride, and the like can be used.

[0070] Among the thioxanthones or quaternary ammonium salts of thioxanthones, a particularly preferred thioxanthone is 2-chlorothioxanthone, from the viewpoint of reducing leachable substances from the cured product. A particularly preferred quaternary ammonium salt of thioxanthones is 2-hydroxy-3-(3,4-dimethyl-9H-thioxanthen-2-yloxy)-N,N,N-trimethyl-1-propanaminium chloride.

[0071] Examples of the α-diketones used as the photopolymerization initiator include diacetyl, dibenzyl, camphorquinone, 2,3-pentadione, 2,3-octadione, 9,10-phenanthrenequinone, 4,4'-oxybenzyl, and acenaphthenequinone.

[0072] Examples of the ketals used as the photopolymerization initiator include benzyl dimethyl ketal and benzyl diethyl ketal.

[0073] Examples of the coumarin compound used as the photopolymerization initiator include 3,3'-carbonylbis(7-diethylaminocoumarin), 3-(4-methoxybenzoyl)coumarin, 3-thienoylcoumarin, 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), phosphorus), 3-benzoyl-6-bromocoumarin, 3,3'-carbonylbiscoumarin, 3-benzoyl-7-dimethylaminocoumarin, 3-benzoylbenzo[f]coumarin, 3-carboxycoumarin, 3-carboxy-7-methoxycoumarin, 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-di Ethylamino-3-(4-methoxybenzoyl)coumarin, 7-diethylamino-3-(4-diethylamino)coumarin, 7-methoxy-3-(4-methoxybenzoyl)coumarin, 3-(4-nitrobenzoyl)benzo[f]coumarin, 3-(4-ethoxycinnamoyl)-7-methoxycoumarin, 3-(4-dimethylaminocinnamoyl)coumarin, 3-(4-diphenylaminocinnamoyl)coumarin, 3-[(3-dimethylbenzothiazol-2-ylidene)acetyl]coumarin, 3-[(1-methylnaphtho[1,2-d]thiazole-2 -ylidene)acetyl]coumarin, 3,3'-carbonylbis(6-methoxycoumarin), 3,3'-carbonylbis(7-acetoxycoumarin), 3,3'-carbonylbis(7-dimethylaminocoumarin), 3-(2-benzothiazolyl)-7-(diethylamino)coumarin, 3-(2-benzothiazolyl)-7-(dibutylamino)coumarin, 3-(2-benzimidazolyl)-7-(diethylamino)coumarin, 3-(2-benzothiazolyl)-7-(dioctylamino)coumarin, 3-acetyl-7-(dimethylamino)coumarin, 3,Examples of compounds include those described in JP-A-9-3109 and JP-A-10-245525, such as 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]quinolizin-11-one, and 10-(2-benzothiazolyl)-2,3,6,7-tetrahydro-1,1,7,7-tetramethyl-1H,5H,11H-[1]benzopyrano[6,7,8-ij]quinolizin-11-one.

[0074] Examples of anthraquinones used as the photopolymerization initiator include anthraquinone, 1-chloroanthraquinone, 2-chloroanthraquinone, 1-bromoanthraquinone, 1,2-benzanthraquinone, 1-methylanthraquinone, 2-ethylanthraquinone, and 1-hydroxyanthraquinone.

[0075] Examples of the benzoin alkyl ethers used as the photopolymerization initiator include benzoin methyl ether, benzoin ethyl ether, benzoin isopropyl ether, and benzoin isobutyl ether.

[0076] Among these, from the viewpoint of being able to further reduce elution from the cured product, 2-benzyl-2- (dimethylamino) -4'-morpholinobutyrophenone, 2-methyl-1- [4- (methylthio) phenyl] -2-morpholinopropan-1-one, 1,2-octanedione, 1- [4- (phenylthio) phenyl] -, 2- (o-benzoyloxime), ethanone, 1- [9-ethyl-6- (2-methylbenzoyl) -9H-carbazol-3-yl] -, 1- (o-acetyloxime), 2-chlorothioxanthone, 2-hydroxy-3- (3,4-dimethyl-9H-thioxanthen-2-yloxy) -N, N, N-trimethyl-1-propaneaminium chloride is preferred.

[0077] The content of the photopolymerization initiator (B) in the dental polymerizable composition of the present invention is not particularly limited. However, from the viewpoint of the curability of the resulting dental polymerizable composition, the content of the photopolymerization initiator (B) is preferably 0.01 to 20 parts by mass per 100 parts by mass of the total polymerizable compounds. If the content of the photopolymerization initiator (B) is less than 0.01 parts by mass, polymerization may not proceed sufficiently, and a molded product may not be obtained. The content of the photopolymerization initiator (B) is more preferably 0.05 parts by mass or more, even more preferably 0.1 parts by mass or more, and particularly preferably 0.5 parts by mass or more, per 100 parts by mass of the total. On the other hand, if the content of the photopolymerization initiator (B) exceeds 20 parts by mass, the polymerization initiator itself may block light, resulting in insufficient curability of the dental polymerizable composition. The content of the photopolymerization initiator (B) is more preferably 15 parts by mass or less, even more preferably 10 parts by mass or less, and particularly preferably 5.0 parts by mass or less, per 100 parts by mass of the total.

[0078] The dental polymerizable composition of the present invention may contain a photopolymerization initiator containing a phosphine oxide skeleton for the purpose of adjusting photocurability, etc. From the viewpoint of elution from the cured product, the content of the photopolymerization initiator containing a phosphine oxide skeleton is preferably 0.5% by mass or less, more preferably 0.3% by mass or less, even more preferably 0.1% by mass or less, and particularly preferably 0% by mass (no photopolymerization initiator) relative to 100% by mass of the total amount of the dental polymerizable composition.

[0079] The dental polymerizable composition of the present invention may contain a Norrish I type photopolymerization initiator for the purpose of adjusting photocurability, etc. From the viewpoint of elution from the cured product, the content of the Norrish I type (intramolecular cleavage type) photopolymerization initiator in the dental polymerizable composition is preferably 0.5% by mass or less, more preferably 0.3% by mass or less, even more preferably 0.1% by mass or less, and particularly preferably 0% by mass (no content).

[0080] The dental polymerizable composition of the present invention is not particularly limited as long as it contains the above-mentioned polyfunctional (meth)acrylic polymerizable compound (A) and photopolymerization initiator (B), and may contain, for example, other components. The method for producing the dental polymerizable composition of the present invention is not particularly limited, and the dental polymerizable composition of the present invention can be produced in accordance with known methods for producing dental polymerizable compositions.

[0081] The dental polymerizable composition of the present invention may contain a polymerization accelerator for the purpose of improving photocurability, within the scope of the present invention. Examples of polymerization accelerators include ethyl 4-(N,N-dimethylamino)benzoate, methyl 4-(N,N-dimethylamino)benzoate, n-butoxyethyl 4-(N,N-dimethylamino)benzoate, 2-(methacryloyloxy)ethyl 4-(N,N-dimethylamino)benzoate, 4-(N,N-dimethylamino)benzophenone, and butyl 4-(N,N-dimethylamino)benzoate. Among these, at least one selected from the group consisting of ethyl 4-(N,N-dimethylamino)benzoate, n-butoxyethyl 4-(N,N-dimethylamino)benzoate, and 4-(N,N-dimethylamino)benzophenone is preferred from the viewpoints of imparting excellent curability to the dental polymerizable composition and reducing leachable substances from the cured product.

[0082] The dental polymerizable composition of the present invention may further contain a filler in order to adjust the paste properties or to increase the mechanical strength of an object shaped from the dental polymerizable composition. Examples of the filler include organic fillers, inorganic fillers, and organic-inorganic composite fillers. One type of filler may be used alone, or two or more types may be used in combination.

[0083] Examples of organic filler materials 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-butadiene copolymer. These may be used alone or in combination of two or more. The shape of the organic filler is not particularly limited, and the particle size of the filler can be appropriately selected and used.

[0084] Examples of inorganic filler materials 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 fluoroaluminosilicate glass. These may also be used alone or in combination of two or more. The shape of the inorganic filler is not particularly limited, and amorphous fillers, spherical fillers, etc. can be appropriately selected and used. Organic-inorganic composite fillers produced by known methods using the above-mentioned organic fillers and inorganic fillers can be used.

[0085] To the dental polymerizable composition of the present invention, a polymer can be added for the purpose of improving flexibility, flowability, etc., within the scope of the present invention. For example, natural rubber, synthetic polyisoprene rubber, liquid polyisoprene rubber and its hydrogenated products, polybutadiene rubber, liquid polybutadiene rubber and its hydrogenated products, styrene-butadiene rubber, chloroprene rubber, ethylene-propylene rubber, acrylic rubber, isoprene-isobutylene rubber, acrylonitrile-butadiene rubber, or a styrene-based elastomer can be added. Specific examples of other polymers that can be added include polystyrene-polyisoprene-polystyrene block copolymers, polystyrene-polybutadiene-polystyrene block copolymers, poly(α-methylstyrene)-polybutadiene-poly(α-methylstyrene) block copolymers, poly(p-methylstyrene)-polybutadiene-poly(p-methylstyrene) block copolymers, and hydrogenated products thereof.

[0086] The dental polymerizable composition of the present invention may optionally contain a softener. Examples of softeners include petroleum-based softeners such as paraffinic, naphthenic, and aromatic process oils, and vegetable oil-based softeners such as paraffin, peanut oil, and rosin. These softeners may be used alone or in combination. The content of the softener is not particularly limited as long as it does not impair the spirit of the present invention, but is typically 200 parts by mass or less, preferably 100 parts by mass or less, per 100 parts by mass of the total polymerizable compound. The content of the polymer and softener is not particularly limited as long as it does not impair the spirit of the present invention, but may be less than 5% by mass, less than 1% by mass, less than 0.1% by mass, or 0% by mass relative to 100% by mass of the total dental polymerizable composition.

[0087] The dental polymerizable composition of the present invention may contain a known stabilizer to inhibit deterioration or adjust photocurability. Examples of the stabilizer include a polymerization inhibitor, an ultraviolet absorber, and an antioxidant. One type of the stabilizer may be used alone, or two or more types may be used in combination.

[0088] Examples of the polymerization inhibitor include hydroquinone, hydroquinone monomethyl ether, dibutylhydroquinone, dibutylhydroquinone monomethyl ether, 4-t-butylcatechol, 2-t-butyl-4,6-dimethylphenol, 2,6-di-t-butylphenol, and 3,5-di-t-butyl-4-hydroxytoluene. From the viewpoints of color tone and curability, the content of the polymerization inhibitor is preferably 0.001 to 5.0 parts by mass, and more preferably 0.01 to 1.0 part by mass, per 100 parts by mass of the total amount of the polymerizable compounds.

[0089] The dental polymerizable composition of the present invention may contain known additives for adjusting the color tone or paste properties. Examples of such additives include colorants (pigments, dyes), organic solvents, and thickeners. One type of additive may be used alone, or two or more types may be used in combination. The content of the additive (e.g., organic solvent) is not particularly limited as long as it does not impair the spirit of the present invention, and may be less than 5% by mass, less than 1% by mass, less than 0.1% by mass, or 0% by mass relative to the total amount (100% by mass) of the dental polymerizable composition.

[0090] The dental polymerizable composition of the present invention is not only easily curable, but also exhibits excellent strength, toughness, and water resistance of the cured product, and produces little leachable material. Therefore, the dental polymerizable composition of the present invention can be used in applications that utilize these advantages, such as intraoral applications. Examples of intraoral applications include dental materials such as dental adhesives, dental cements, dental filling and restorative materials, denture base materials, and dental occlusal splints; and materials for treating sleep disorders (particularly, devices for treating sleep apnea syndrome). The dental polymerizable composition of the present invention is suitable as a material for stereolithography, and is particularly suitable for dental occlusal splints, denture base materials, and devices for treating sleep apnea syndrome, which are fabricated by stereolithography. An example of a preferred embodiment of a dental adhesive is shown below. An example of a preferred embodiment of a dental adhesive is a dental polymerizable composition containing a polyfunctional (meth)acrylic polymerizable compound (A), a photopolymerization initiator (B), a monofunctional (meth)acrylic polymerizable compound (C), and, as optional components, water, a water-soluble organic solvent such as ethanol or acetone, a polymerization accelerator, and an inorganic filler. Examples of the polyfunctional (meth)acrylic polymerizable compound (A) include 2,2-bis[4-(2-hydroxy-3-methacryloyloxypropoxy)phenyl]propane (commonly known as "Bis-GMA"), glycerol di(meth)acrylate, etc. Examples of the monofunctional (meth)acrylic polymerizable compound (C) include monofunctional (meth)acrylic polymerizable monomers containing an acidic group and monofunctional (meth)acrylic polymerizable monomers containing a hydroxyl group.The dental adhesive preferably contains, based on the total amount of the dental adhesive, 10 to 90% by mass of a polyfunctional (meth)acrylic polymerizable compound (A), 0.001 to 10% by mass of a photopolymerization initiator (B), 1.0 to 50% by mass of a monofunctional (meth)acrylic polymerizable compound (C), 0 to 50% by mass of water, and 0 to 50% by mass of a water-soluble organic solvent, and more preferably contains 20 to 80% by mass of a polyfunctional (meth)acrylic polymerizable compound (A) and 0.01 to 5.0% by mass of a photopolymerization initiator (B). %, 5.0 to 40 mass% of the monofunctional (meth)acrylic polymerizable compound (C), 5 to 40 mass% of water, and 5 to 40 mass% of a water-soluble organic solvent are more preferred, and those containing 30 to 70 mass% of the polyfunctional (meth)acrylic polymerizable compound (A), 0.1 to 1.0 mass% of the photopolymerization initiator (B), 10 to 30 mass% of the monofunctional (meth)acrylic polymerizable compound (C), 10 to 30 mass% of water, and 10 to 30 mass% of a water-soluble organic solvent are even more preferred.

[0091] The shape of a cured product obtained using the dental polymerizable composition of the present invention can be changed depending on the intended use. Furthermore, the types and contents of the polyfunctional (meth)acrylic polymerizable compound (A), the photopolymerization initiator (B), and various optional components (monofunctional (meth)acrylic polymerizable compound (C), polymerization accelerator, filler, polymer, softener, stabilizer, additive, etc.) can be adjusted as needed for each intended use, such as a dental occlusal splint, a denture base material, or a treatment device for sleep apnea syndrome.

[0092] The dental polymerizable composition of the present invention can be used in a variety of applications by taking advantage of its properties, such as the fact that when cured by light, it can give molded articles or three-dimensional objects, as well as other shaped articles, which have a small volumetric shrinkage rate and excellent dimensional accuracy, and which have excellent strength, toughness, and water resistance when cured. For example, it can be used in the production of three-dimensional objects by optical three-dimensional modeling, the production of various molded articles such as film-like articles or molded articles by casting or casting, and molds for coating and vacuum forming.

[0093] Among these, the dental polymerizable composition of the present invention is suitable for use in the above-mentioned three-dimensional modeling method, and in this case, a three-dimensional model that has excellent dimensional accuracy, toughness, and mechanical properties can be smoothly produced while maintaining a small volumetric shrinkage rate upon photocuring.

[0094] The dental polymerizable composition of the present invention is excellent in strength, toughness, and water resistance, has not too high mechanical properties, has appropriate flexibility, and produces little eluate. Therefore, among intraoral uses, the dental polymerizable composition is particularly suitable for use as an orthodontic mouthpiece or aligner for the purpose of correcting the dentition and / or jaw position, or a dental soft splint such as a sports mouthguard.

[0095] Another embodiment of the present invention is a method for producing a three-dimensional object by photolithography using any of the dental polymerizable compositions described above. The photolithography method is not particularly limited, and a liquid vat photopolymerization method such as a laser-based stereolithography apparatus (SLA) or a digital light processing (DLP)-based SLA can be used. Low Force Stereolithography (LFS) can also be used as the SLA.

[0096] When performing stereolithography using the dental polymerizable composition of the present invention, any known stereolithography method and device (e.g., a stereolithography machine such as DIGITALWAX (registered trademark) 028J-Plus manufactured by DWS) can be used. Among these, in the present invention, it is preferable to use active energy rays as the light energy for curing the resin. "Active energy rays" refers to energy rays capable of curing the dental polymerizable composition, such as ultraviolet rays, electron beams, X-rays, radioactive rays, and high frequency rays. For example, active energy rays may be ultraviolet rays having a wavelength of 300 to 400 nm. Examples of light sources for active energy rays include lasers such as Ar lasers and He—Cd lasers; and lighting such as halogen lamps, xenon lamps, metal halide lamps, LEDs, mercury lamps, and fluorescent lamps. Lasers are particularly preferred. When a laser is used as a light source, it is possible to increase the energy level and shorten the modeling time, and the excellent focusing properties of the laser beam can be utilized to obtain a three-dimensional object with high modeling accuracy.

[0097] As described above, when performing optical three-dimensional modeling using the dental polymerizable composition of the present invention, any known method and known optical modeling system may be used, and there are no particular limitations. However, a representative example of an optical three-dimensional modeling method preferably used in the present invention is a method in which a step of selectively irradiating a dental polymerizable composition with an active energy ray to form a cured layer having a desired pattern, followed by a lamination step of supplying an uncured liquid dental polymerizable composition to the cured layer and similarly irradiating it with an active energy ray to form a new cured layer continuous with the cured layer, is repeated to finally obtain the desired three-dimensional object. The three-dimensional object obtained thereby may be used as is, or, in some cases, may be further post-cured by light irradiation or heat to further improve its mechanical properties or shape stability, etc., before use.

[0098] The structure, shape, size, etc. of a three-dimensional object obtained by the optical three-dimensional modeling method are not particularly limited and can be determined depending on the respective applications. Typical applications of the optical three-dimensional modeling method of the present invention include the production of models for verifying the appearance design during the design process, models for checking the functionality of parts, resin molds for producing casting molds, base models for producing metal molds, and direct molds for prototype molds. More specifically, examples include the production of models or processing models for precision parts, electrical parts, electronic parts, furniture, architectural structures, automotive parts, various containers, castings, metal molds, master molds, etc. In particular, the excellent strength and toughness of the molded objects of the dental polymerizable composition can be utilized to extremely effectively use them in applications such as cushioning materials with complex shapes in structures (e.g., architectural structures), vacuum forming molds, etc.

[0099] Next, the present invention will be explained in more detail by way of examples, but the present invention is not limited to these examples in any way, and many modifications can be made by a person having ordinary skill in the art within the scope of the technical idea of ​​the present invention.

[0100] Each component used in the dental polymerizable compositions according to the Examples and Comparative Examples will be explained below together with its abbreviation.

[0101] [Polyfunctional urethane-modified (meth)acrylic polymerizable compound (A)-I-1] UDMA: 2,2,4-trimethylhexamethylenebis(2-carbamoyloxyethyl)dimethacrylate (manufactured by Kyoeisha Chemical Co., Ltd., molecular weight: 471) U4TH: N,N'-(2,2,4-trimethylhexamethylene)bis[2-(aminocarboxy)propane-1,3-diol]tetramethacrylate (manufactured by Kyoeisha Chemical Co., Ltd., molecular weight: 673)

[0102] [Polyfunctional (meth)acrylic polymerizable compound (A)-I-2) not containing a urethane bond] D2.6E: 2,2-bis(4-methacryloyloxypolyethoxyphenyl)propane (average number of moles of ethoxy groups added: 2.6, "BPE-100" manufactured by Shin-Nakamura Chemical Co., Ltd., molecular weight: approximately 478)

[0103] [Polyfunctional urethanized (meth)acrylic polymerizable compound (A)-II-1] <Synthesis Example 1> [Production of polyfunctional urethanized (meth)acrylic polymerizable compound (A)-II-1-a] (1) 250 g of isophorone diisocyanate and 0.15 g of di-n-butyltin dilaurate were placed in a 5 L four-neck flask equipped with a stirrer, a temperature controller, a thermometer, and a condenser, and the mixture was heated to 70° C. with stirring. (2) Meanwhile, 2500 g of polyester polyol ("Kuraray Polyol (registered trademark) P-2050" manufactured by Kuraray Co., Ltd.; a polyol composed of sebacic acid and 3-methyl-1,5-pentanediol, weight average molecular weight Mw: 2000) was placed in a dropping funnel equipped with a side tube, and the liquid in the dropping funnel was added dropwise to the flask (1) above. The solution in the flask (1) was added dropwise at a constant rate over 4 hours while stirring and maintaining the internal temperature of the flask at 65-75°C. After the addition was completed, the mixture was stirred at the same temperature for 2 hours to allow the reaction to proceed. (3) Next, a solution prepared by uniformly dissolving 150 g of 2-hydroxyethyl acrylate and 0.4 g of hydroquinone monomethyl ether in a separate dropping funnel was added dropwise at a constant rate over 2 hours to the flask (2) while maintaining the internal temperature of the flask at 55-65°C. The reaction was then continued for 4 hours while maintaining the temperature of the solution in the flask at 70-80°C, yielding a urethane-modified (meth)acrylic polymerizable compound (A)-II-1-a. The weight-average molecular weight Mw of the polyfunctional urethane-modified (meth)acrylic polymerizable compound (A)-II-1-a was determined by GPC analysis to be 2600.

[0104] The weight average molecular weight Mw of the compound synthesized above means the weight average molecular weight in terms of polystyrene determined by gel permeation chromatography (GPC).

[0105] Multifunctional urethane-modified (meth)acrylic polymerizable compound (A)-II-1-b: polyether-based urethane acrylate, molecular weight: 1600, "NK Oligo UA-160™" manufactured by Shin-Nakamura Chemical Co., Ltd.

[0106] [Polyfunctional (meth)acrylic polymerizable compound (A)-II-2) not containing a urethane bond] A-BPE-30: 2,2-bis(4-methacryloyloxypolyethoxyphenyl)propane (average number of moles of ethoxy groups added: 30, "A-BPE-30" manufactured by Shin-Nakamura Chemical Co., Ltd., molecular weight: approximately 1656)

[0107] [Monofunctional (meth)acrylic polymerizable compound (C)] POBA: m-phenoxybenzyl acrylate (manufactured by Kyoeisha Chemical Co., Ltd.) A-LEN-10: ethoxylated o-phenylphenol acrylate (manufactured by Shin-Nakamura Chemical Co., Ltd.)

[0108] [Photopolymerization initiators (B) not containing a phosphine oxide skeleton] AK1: 2-benzyl-2-(dimethylamino)-4'-morpholinobutyrophenone (manufactured by IGM Resin B.V. (NL) Omnirad 369) OX1: 1,2-octanedione, 1-[4-(phenylthio)phenyl]-, 2-(o-benzoyloxime) (manufactured by BASF Japan Ltd. Irgacure OXE-01) CT1: 2-chlorothioxanthone (manufactured by Tokyo Chemical Industry Co., Ltd.)

[0109] [Photopolymerization initiators containing a phosphine oxide skeleton] TPO: diphenyl(2,4,6-trimethylbenzoyl)phosphine oxide BAPO: phenylbis(2,4,6-trimethylbenzoyl)phosphine oxide

[0110] [Polymerization inhibitor] BHT: 3,5-di-t-butyl-4-hydroxytoluene

[0111] [Examples 1 to 13 and Comparative Examples 1 and 2] Dental polymerizable compositions according to Examples 1 to 13 and Comparative Examples 1 and 2 were prepared by mixing the components in the amounts (parts by mass) shown in Tables 1 and 2 at room temperature (20°C ± 15°C, JIS (Japanese Industrial Standards) Z 8703:1983).

[0112] The resulting dental polymerizable composition was used to fabricate a test piece (length 64.0 mm, width 10.0 mm, thickness 3.3 mm) having the dimensions described in 6.4 of JDMAS 253:2020 (Photopolymerizable resin for 3D printers for dental hard splints) using a stereolithography machine (DIGITALWAX® 020D manufactured by DWS). Various tests were performed on this test piece as a cured product of the dental polymerizable composition.

[0113] <Strength (Flexural Modulus, Flexural Strength), Toughness (Flexural Displacement at Break)> For the cured products of the dental polymerizable compositions according to each Example and Comparative Example, after storage in air for one day, strength (flexural modulus, flexural strength) and toughness (flexural displacement at break) were measured. Measurements were performed using a universal testing machine (Shimadzu Corporation, Autograph AG-I 100kN) at a fulcrum distance of 50 mm and a crosshead speed of 5 mm / min (n=5) in accordance with JDMAS 253:2020 (Photopolymerizable Resins for 3D Printers for Dental Hard Splints). The flexural strength test was performed in accordance with 6.4. The measurements were performed using a universal testing machine (Shimadzu Corporation, Autograph AG-I 100kN) at a fulcrum distance of 50 mm and a crosshead speed of 5 mm / min (n=5). The average values ​​of the measured values ​​are shown in Tables 1 and 2. The flexural modulus is preferably in the range of 300 MPa to less than 2000 MPa, more preferably 400 MPa to 1500 MPa, and even more preferably 500 MPa to 1000 MPa, because these compositions are particularly suitable for use as dental occlusal splints. The bending strength (three-point bending strength) is preferably 10 MPa or more, more preferably 15 MPa or more, and even more preferably 20 MPa or more. As for the displacement at break, it is preferable that no break occurs. The displacement at break is evaluated according to the following criteria, with "A" (good toughness) and "B" (moderate toughness) being considered acceptable. <Evaluation criteria> A: The cured product broke with a displacement of 15 mm or more. B: The cured product broke with a displacement of more than 10 mm but less than 15 mm. C: The cured product broke with a displacement of 10 mm or less.

[0114] <Water Resistance> The cured products of the dental polymerizable compositions according to each Example and Comparative Example were immersed in water at 37°C for 168 hours, and then the flexural strength was measured in the same manner as in the flexural strength test (n=5). The average values ​​of the measured values ​​are shown in Tables 1 and 2. When the flexural strength measurement result (unit: MPa) in the flexural strength test above is taken as the "initial flexural strength," the flexural strength after storage in air for one day and then immersion in water at 37°C for 168 hours is considered to be excellent in water resistance if the change rate (decrease rate) in flexural strength shown below is 20% or less. In Tables 1 and 2, the flexural strength after immersion in water at 37°C for 168 hours is referred to as the "flexural strength after immersion." Change rate (decrease rate) in flexural strength (%) = [{initial flexural strength (MPa) - flexural strength after immersion in water at 37°C for 168 hours (MPa)} / initial flexural strength (MPa)] × 100

[0115] <Dissolution Properties> The obtained dental polymerizable composition was used to form disks with a diameter of 15 mm and a thickness of 1.0 mm using a stereolithography machine (DIGITALWAX (registered trademark) 020D, manufactured by DWS). One of the obtained disks was immersed in 2.0 ml of ethanol at 50°C for 72 hours in a 10 ml glass bottle, after which the disk was removed, the ethanol was distilled off, and the mass of the extract was measured (n = 1). The obtained extract was dissolved in THF, and the main components were identified using GC-MS (apparatus: GCMS-QP2010 Ultra, manufactured by Shimadzu Corporation; column: Ultra ALLOY-1, inner diameter 0.25 mm, length 15 m, film thickness 0.15 μm, manufactured by Frontier Labs).

[0116]

[0117]

[0118] As shown in Tables 1 and 2, the objects formed using the dental polymerizable compositions of Examples 1 to 13 were excellent in strength, toughness, and water resistance, and had lower levels of eluted substances than the objects formed using the dental polymerizable compositions of Comparative Examples 1 and 2. Furthermore, when the eluted substances from the objects formed using the dental polymerizable compositions of Examples 1 to 13 were analyzed by GC-MS, the detected amounts were small, making it difficult to identify the components. Meanwhile, trimethylbenzaldehyde, trimethylbenzoic acid, and diphenylphosphine derivatives were detected as eluted substances from the objects formed using the dental polymerizable compositions of Comparative Examples 1 and 2. This confirms that the dental polymerizable compositions of Examples 1 to 13 had significantly lower levels of eluted substances and were therefore safer than the dental polymerizable compositions of Comparative Examples 1 and 2.

[0119] The dental polymerizable composition of the present invention has excellent strength, toughness, and water resistance when cured, and produces little elution from the cured product, and is therefore ideal for intraoral applications such as various dental materials (particularly dental occlusal splints and denture base materials produced by stereolithography) or various sleep disorder treatment materials (particularly treatment devices for sleep apnea syndrome).

Claims

1. A dental polymerizable composition comprising a polyfunctional (meth)acrylic polymerizable compound (A) and a photopolymerization initiator (B) not containing a phosphine oxide skeleton.

2. The dental polymerizable composition according to claim 1, wherein the photopolymerization initiator (B) not containing a phosphine oxide skeleton contains a Norrish type II photopolymerization initiator.

3. The dental polymerizable composition according to claim 1 or 2, wherein the polyfunctional (meth)acrylic polymerizable compound (A) contains a polyfunctional (meth)acrylic polymerizable compound (A)-I having a molecular weight of less than 1,000, and / or a polyfunctional (meth)acrylic polymerizable compound (A)-II having a molecular weight of 1,000 or more.

4. The dental polymerizable composition according to claim 3, wherein the polyfunctional (meth)acrylic polymerizable compound (A) contains a polyfunctional urethane-modified (meth)acrylic polymerizable compound (A)-I-1 having a molecular weight of less than 1,000 and containing a urethane bond, and / or a polyfunctional urethane-modified (meth)acrylic polymerizable compound (A)-II-1 having a molecular weight of 1,000 or more and containing a urethane bond.

5. The dental polymerizable composition according to claim 4, wherein the polyfunctional (meth)acrylic polymerizable compound (A)-I-1 contains a (meth)acrylate that does not contain a polymer structure in one molecule.

6. The dental polymerizable composition according to claim 4, wherein the polyfunctional urethane-modified (meth)acrylic polymerizable compound (A)-II-1 contains a (meth)acrylate containing, in one molecule, at least one structure selected from the group consisting of polyester, polycarbonate, polyurethane, polyether, polyconjugated diene, and hydrogenated polyconjugated diene.

7. The dental polymerizable composition according to claim 4, wherein the polyfunctional urethane-type (meth)acrylic polymerizable compound (A)-II-1 contains a (meth)acrylate containing at least one polyol moiety selected from the group consisting of polyesters, polycarbonates, polyurethanes, polyethers, polyconjugated dienes, and hydrogenated polyconjugated dienes, each of which has a structure derived from an aliphatic chain diol unit having 4 to 18 carbon atoms and a branched structure in one molecule.

8. The dental polymerizable composition according to claim 1 or 2, wherein the photopolymerization initiator (B) not containing a phosphine oxide skeleton contains at least one member selected from the group consisting of α-aminoketone compounds, oxime ester compounds, and thioxanthones.

9. The dental polymerizable composition according to claim 1 or 2, further comprising a monofunctional (meth)acrylic polymerizable compound (C).

10. The dental polymerizable composition according to claim 9, wherein the monofunctional (meth)acrylic polymerizable compound (C) contains a monofunctional (meth)acrylic polymerizable compound (C)-I containing a cyclic structure.

11. The dental polymerizable composition according to claim 10, wherein the monofunctional (meth)acrylic polymerizable compound (C)-I contains one or more aromatic rings.

12. The dental polymerizable composition according to claim 10, wherein the monofunctional (meth)acrylic polymerizable compound (C)-I contains a plurality of aromatic rings.

13. A material for stereolithography, comprising the dental polymerizable composition according to claim 1 or 2.

14. A denture base material comprising the cured product of the material for photopolymerization according to claim 13.

15. A dental occlusal splint comprising a cured product of the material for photopolymerization according to claim 13.

16. A material for treating sleep disorders, comprising a cured product of the photopolymerization material according to claim 13.

17. A method for producing a three-dimensional object by optical three-dimensional modeling using the dental polymerizable composition according to claim 1 or 2.