Dental curable composition capable of obtaining high mechanical strength

Abstract

Provided are a dental curable composition and an inorganic filler with which high mechanical strength can be obtained after curing. The present invention provides a dental curable composition containing a silane coupling material represented by formula (1) and / or an inorganic filler surface-treated with a silane coupling material represented by formula (1).

Description

Technical Field

[0001] This invention relates to a dental curing composition containing a free radical polymerizable coupling agent having a methacrylamide structure. Background Technology

[0002] In dental medicine, dental curing compositions consisting of polymeric monomers, inorganic fillers, and polymerization initiators are widely used. These are commonly referred to as dental composite resins and are used for various purposes, including direct restoration of tooth defects caused by cavities, inlays, crowns, bridges, abutment tooth construction for crown defects, and bulk materials for dental CAD / CAM (computer-aided design / computer-aided manufacturing).

[0003] Dental composite resins typically use (meth)acrylic acid derivative monomers such as methyl methacrylate, triethylene glycol dimethacrylate, and urethane-based dimethacrylate. In the free radical polymerization (hereinafter referred to as free radical polymerization) of these vinyl monomers, carbon-carbon double bonds break, becoming single bonds, thereby forming a high molecular weight polymer that cures. In addition to vinyl monomers, inorganic fillers are added to composite resins to improve mechanical strength. Typically, these inorganic fillers are surface-treated with silane coupling materials containing polymerizable groups to improve wettability and mechanical strength.

[0004] In the dental field, γ-methacryloyloxypropyltrimethoxysilane (hereinafter referred to as KBM-503) has historically been widely used as a silane coupling material. However, when using inorganic fillers with surface treatments based on this compound, the low hydrophobicity leads to easy hydrolysis and low material durability. Consequently, it suffers from insufficient mechanical strength.

[0005] Therefore, in order to improve the durability and filling rate of materials, the following methods have been proposed: a method using a free radical polymerizable silane coupling material with a cyclic compound as the backbone (Japanese Patent No. 7118549); a method using a silane coupling material having multiple polymerizable groups (Japanese Patent No. 5416447); a method using a silane coupling material with a long alkyl chain (Japanese Patent No. 6220723); a method using a silane coupling material having hydroxyl and urethane groups (Japanese Patent No. 7104490); and a method using a silane having an epoxy ring and urethane groups. Methods for coupling materials (Japanese Patent No. 7104489), methods for using silane coupling materials having fluorinated organic groups (Japanese Patent No. 7093628), methods for using two silane coupling materials (Japanese Patent No. 6220723 and Japanese Patent No. 6793241), and methods for using free radical polymerizable silane coupling materials having urethane bonds (Japanese Patent No. 6841915, Japanese Patent No. 7104488, Japanese Patent No. 7104487, and Japanese Patent No. 7104486). Summary of the Invention

[0006] However, when the methods described in the above literature are applied to resin-cured bodies for dental cutting, there is room for improvement in mechanical strength.

[0007] The object of the present invention is to provide a dental curable composition that can achieve high mechanical strength after curing.

[0008] The inventors conducted in-depth research and discovered that by surface-treating inorganic fillers with a silane coupling material represented by the chemical structural formula (1) below, high affinity for free radical polymerizable monomers, particularly free radical polymerizable monomers containing urethane bonds and hydrogen bonds, and high dispersibility of the inorganic filler are imparted. Consequently, high mechanical strength can be imparted when used in dental curable compositions. This invention is based on the above insights.

[0009]

[0010] The present invention provides a dental curable composition comprising a silane coupling material represented by formula (1) and / or an inorganic filler surface-treated with a silane coupling material represented by formula (1) below.

[0011]

[0012] The dental curable composition according to the present invention can achieve high mechanical strength after curing. Detailed Implementation

[0013] The dental curable composition of the present invention comprises a silane coupling material represented by formula (1) and / or an inorganic filler that has been surface-treated with a silane coupling material represented by formula (1).

[0014] By surface-treating inorganic fillers with silane coupling materials represented by formula (1), high affinity for polymerizable monomers, especially free radical polymerizable monomers with urethane bonds and hydrogen bonds, and high dispersibility of inorganic fillers are exhibited. As a result, the cured body of the dental curable composition is endowed with high mechanical strength and flexibility.

[0015] This high affinity effect is particularly pronounced in free radical polymerizable monomers containing urethane bonds and hydrogen bonds. This can be attributed to the presence of nitrogen atoms and amide bonds in formula (1).

[0016]

[0017] It can be assumed that the inorganic filler, which has been surface-treated with the silane coupling material represented by formula (1), introduces nitrogen atoms and amide bonds on its surface, and exhibits high affinity with free radical polymerizable monomers with urethane bonds and hydrogen bonds.

[0018] Furthermore, it is believed that the presence of amide bonds leads to the formation of inter-amide group hydrogen bonds, resulting in a strong bond between the inorganic fillers that have undergone surface treatment with silane coupling materials. In this invention, high filler content of inorganic fillers can be achieved, resulting in high mechanical strength.

[0019] The dental curing composition of the present invention may contain an inorganic filler that has been surface-treated using a silane coupling material represented by formula (1).

[0020] In the dental curing composition of the present invention, the amount of silane coupling material treated relative to 100 parts by weight of the inorganic filler during surface treatment can be 0.1 to 20 parts by weight.

[0021] In the dental curing composition of the present invention, the amount of inorganic filler surface-treated with a silane coupling material represented by formula (1) may be 1 to 90 parts by weight relative to 100 parts by weight of the dental curing composition as a whole.

[0022] The dental curing composition of the present invention may further comprise a free radical polymerizable monomer and a polymerization initiator.

[0023] The dental curing composition of the present invention may also contain an inorganic filler that has been surface-treated with a surface treatment agent other than the silane coupling material represented by formula (1).

[0024] In the dental curable composition of the present invention, the free radical polymerizable monomer may have urethane bonds.

[0025] In the dental curable composition of the present invention, the free radical polymerizable monomer may have one or more hydroxyl groups and more than one difunctional polymerizable group.

[0026] The dental curing composition of the present invention may have a monomer represented by formula (2) as a free radical polymerizable monomer.

[0027]

[0028] In the dental curing composition of the present invention, the amount of free radical polymerizable monomer having the compound represented by formula (2) may be 1 to 10 parts by weight relative to 100 parts by weight of the dental curing composition as a whole.

[0029] In the dental curing composition of the present invention, the weight ratio of the silane coupling material represented by formula (1) to the free radical polymerizable monomer having the compound represented by formula (2) may be in the range of 1:0.5 to 1:20.

[0030] In the dental curable composition of the present invention, the inorganic filler that has been surface-treated with a silane coupling material represented by formula (1) can be a spherical nanofiller with an average particle size of 0.01 to 1 μm.

[0031] In the dental curing composition of the present invention, the inorganic filler that has been surface-treated with a silane coupling material represented by formula (1) can be a fragmented inorganic filler with an average particle size of 0.01 to 10 μm.

[0032] In the dental curable composition of the present invention, the inorganic filler that has been surface-treated with a silane coupling material represented by formula (1) can be an aggregated inorganic filler with an average particle size of 0.01 to 10 μm.

[0033] In the dental curable composition of the present invention, the aggregated inorganic filler may be composed of SiO2: 50-99% by weight and ZrO2: 1-50% by weight.

[0034] The polymerization initiator of the dental curing composition of the present invention has a 10-hour half-life temperature between 70°C and 170°C.

[0035] In the dental curing composition of the present invention, the flexural strength of the cured dental curing composition after being stored in water at 37°C for 1 week can be 300 MPa or more.

[0036] In the dental curing composition of the present invention, the flexural modulus of the cured dental curing composition after being stored in water at 37°C for 1 week can be 20 GPa or higher.

[0037] The dental curing composition of the present invention can be used in the manufacture of resin-cured bodies for dental cutting.

[0038] The dental curing composition of the present invention can be used in the manufacture of dental composite resins.

[0039] The dental curing composition of the present invention can be used as a dental curing composition for three-dimensional (3D) printing.

[0040] The present invention provides an inorganic filler that has undergone surface treatment using a silane coupling material represented by formula (1).

[0041]

[0042] [Silane coupling material represented by formula (1)]

[0043] The silane coupling material used in this invention has a methacrylamide structure, specifically the structure represented by formula (1). In this invention, the silane coupling material represented by formula (1) can be used alone or in combination with a plurality of other surface treatment agents for surface treatment. Other surface treatment agents are not particularly limited and can be listed as follows: 3-methacryloyloxypropyltrimethoxysilane, 8-methacryloyloxyoctyltrimethoxysilane, titanium acetylacetonate, zirconium acetoacetate, etc.

[0044]

[0045] Regarding the silane coupling material represented by formula (1), the dental curing composition of the present invention may be contained in the form of the silane coupling material represented by formula (1) itself before surface treatment, or in the form of an inorganic filler that has been surface-treated using the silane coupling material represented by formula (1). The dental curing composition of the present invention may contain both the silane coupling material represented by formula (1) itself and an inorganic filler that has been surface-treated using the silane coupling material represented by formula (1). The dental curing composition of the present invention may contain an inorganic filler that has been surface-treated using the silane coupling material represented by formula (1) but not the silane coupling material represented by formula (1) itself. The dental curing composition of the present invention may contain the silane coupling material represented by formula (1) itself but not the inorganic filler that has been surface-treated using the silane coupling material represented by formula (1).

[0046] In this invention, when the dental curing composition contains the silane coupling material represented by formula (1), the composition ratio of the silane coupling material represented by formula (1) can be set to 0.05 to 5.0% by weight of the total dental curing composition when the dental curing composition does not contain a polymerization initiator, and to 0.05 to 5.0% by weight of the dental curing composition after removing the polymerization initiator when the dental curing composition contains a polymerization initiator. In other words, when the dental curing composition does not contain a polymerization initiator, it can be set to 0.05 to 5.0 parts by weight relative to 100 parts by weight of the total dental curing composition, and when the dental curing composition contains a polymerization initiator, it can be set to 0.05 to 5.0 parts by weight relative to 100 parts by weight of the dental curing composition after removing the polymerization initiator. At a content below 0.05% by weight, the silane coupling material may not be sufficiently introduced. In addition, when the content is greater than 5.0% by weight, condensates of only silane coupling materials are sometimes formed, which affects the mechanical strength of the cured material.

[0047] In this invention, when the dental curable composition includes an inorganic filler that has been surface-treated using a silane coupling material represented by formula (1), the treatment concentration of the inorganic filler using the silane coupling material represented by formula (1) during surface treatment can be set to 0.1 to 20% by weight of the inorganic filler. In other words, the treatment amount of the silane coupling material relative to 100 parts by weight of the inorganic filler during surface treatment can be set to 0.1 to 20 parts by weight. At treatment amounts below 0.1% by weight, the silane coupling material may not be sufficiently introduced. Furthermore, at amounts greater than 20% by weight, a condensate of only the silane coupling material may be formed, affecting the mechanical strength of the cured product.

[0048] [Inorganic filler]

[0049] There are no particular limitations on the inorganic fillers that can be used in this invention, and examples include: silica, alumina, silica-titanium oxide, silica-zirconia, silica-alumina, borosilicate glass, sodium glass, barium glass, strontium glass, glass ceramics, aluminosilicate glass, barium borosilicate glass, strontium borosilicate glass, fluoroaluminosilicate glass, strontium calcium fluoroaluminosilicate glass, etc. The dental curing composition of this invention may contain these inorganic fillers in a state after surface treatment using a silane coupling material represented by formula (1). The dental curing composition of this invention may contain these inorganic fillers in a state before surface treatment using a silane coupling material represented by formula (1). In the case where the dental curing composition of this invention contains the silane coupling material represented by formula (1) itself, only inorganic fillers that have not been surface treated using the silane coupling material represented by formula (1) may be included as inorganic fillers.

[0050] When the dental curing composition of the present invention contains the silane coupling material represented by formula (1) itself, the composition ratio of the inorganic filler in the dental curing composition of the present invention prior to surface treatment using the silane coupling material represented by formula (1) is not particularly limited. When the dental curing composition does not contain a polymerization initiator, it can be set to 0.95 to 85% by weight of the total dental curing composition, or 50 to 85% by weight. When the dental curing composition contains a polymerization initiator, it can be set to 0.95 to 85% by weight of the dental curing composition after removing the polymerization initiator, or 50 to 85% by weight of the dental curing composition after removing the polymerization initiator. That is, when the dental curing composition does not contain a polymerization initiator, the content can be set to 0.95 to 85 parts by weight, or 50 to 85 parts by weight, relative to 100 parts by weight of the total dental curing composition. When the dental curing composition contains a polymerization initiator, the content can be set to 0.95 to 85 parts by weight, or 50 to 85 parts by weight, relative to 100 parts by weight of the dental curing composition after removing the polymerization initiator. At content below 0.95% by weight, the mechanical strength of the cured product may sometimes decrease. Furthermore, at content above 85% by weight, the workability may sometimes deteriorate due to excessively high viscosity of the adjusted paste.

[0051] The composition ratio of the inorganic filler, which has undergone surface treatment using the silane coupling material represented by formula (1), in the dental curing composition of the present invention is not particularly limited. When the dental curing composition does not contain a polymerization initiator, it can be set to 1-90% by weight of the total dental curing composition, or 70-85% by weight. When the dental curing composition contains a polymerization initiator, it can be set to 1-90% by weight of the dental curing composition after removing the polymerization initiator, or 70-85% by weight. That is, when the dental curing composition does not contain a polymerization initiator, it can be set to 1-90 parts by weight, or 70-85 parts by weight, relative to 100 parts by weight of the total dental curing composition; when the dental curing composition contains a polymerization initiator, it can be set to 1-90 parts by weight, or 70-85 parts by weight, relative to 100 parts by weight of the dental curing composition after removing the polymerization initiator. At a content of less than 1% by weight, the mechanical strength of the cured product may sometimes decrease. Furthermore, at concentrations greater than 90 g / L, the adjusted paste sometimes becomes less workable due to excessive viscosity. In the case where the dental curing composition of the present invention comprises both the silane coupling material itself represented by formula (1) and an inorganic filler that has been surface-treated using the silane coupling material represented by formula (1), the composition ratio after surface treatment using the silane coupling material represented by formula (1) refers to the composition ratio after surface treatment using the silane coupling material itself contained in the dental curing composition. That is, it refers to the total composition ratio based on the surface-treated material, such as the inorganic filler, which has been surface-treated using the silane coupling material itself represented by formula (1) contained in the dental curing composition, and the surface-treated material, such as the inorganic filler, which has been surface-treated using the silane coupling material represented by formula (1) before mixing with the silane coupling material itself represented by formula (1).

[0052] Examples of shapes for inorganic fillers used in this invention include spherical and amorphous fillers. Spherical inorganic fillers refer to inorganic fillers whose particles, as observed in electron microscopy, exhibit roundness or lack arbitrary angles. By being spherical, a sliding effect and mitigation of interference between fillers are expected. Amorphous inorganic fillers refer to amorphous particles obtained through mechanical pulverization. Amorphous particles refer to shapes with arbitrary angles. By being amorphous, the effects of suppressing flowability and maintaining the shapeability of the paste are expected. In the dental curing composition of this invention, from the viewpoint of balancing the flowability and shapeability of the paste, spherical fillers and amorphous fillers can be used together. Furthermore, two or more fillers with different shapes and / or average particle sizes can be mixed or combined. By combining two or more fillers, the fillers are densely packed, and the interaction points between the fillers and polymerizable monomers or between the fillers themselves increase.

[0053] Furthermore, the average particle size of the inorganic filler used in this invention can be set to 0.01–100 μm, 0.01–20 μm, or 0.01–10 μm. Additionally, in this invention, the average particle size of the inorganic filler surface-treated with the silane coupling material represented by formula (1) can be set to 0.01–100 μm, 0.01–20 μm, or 0.01–10 μm. When the average particle size of the inorganic filler is less than 0.01 μm, the dental curing composition becomes viscous, and sometimes the workability of the paste deteriorates. On the other hand, when the average particle size of the inorganic filler is greater than 100 μm, it sometimes leads to a decrease in the mechanical strength of the cured product. By using an average particle size of the inorganic filler in the range of 0.01–10 μm, appropriate paste dispersibility can be obtained, and high mechanical strength after curing can be achieved. In this invention, the average particle size of the inorganic filler can be measured using, for example, a particle size analyzer, a laser diffraction particle size analyzer, or an electron microscope. It should be noted that the average particle size of the inorganic filler is substantially unaffected by surface treatment with a surface treatment agent. Therefore, the average particle size of the inorganic filler can be either a state without surface treatment with a surface treatment agent or a state with surface treatment with a surface treatment agent.

[0054] The shape of the inorganic filler is not particularly limited and can be spherical nanofillers. Being spherical improves the workability of the paste and increases the filling rate of the dental curing composition. Spherical nanofillers refer to nanoscale fillers with spherical particles, as observed in electron microscopy photographs. Their spherical shape allows for sliding effects and reduces interference between fillers. The average particle size of the spherical nanofillers can be set to 0.01–1 μm, 0.02–0.5 μm, or 0.05–0.1 μm. When the average particle size is less than 0.01 μm, the specific surface area increases, thickening the paste, sometimes preventing the addition of sufficient filler and reducing the mechanical strength of the cured product. On the other hand, when the average particle size is greater than 1 μm, the surface area of ​​the spherical filler decreases, sometimes making it impossible to obtain a cured product with high formability in the dental curing composition. It should be noted that the average particle size of the spherical nanofillers is substantially unaffected by surface treatment using surface treatment agents. Therefore, the average particle size of the spherical nanofiller can be either the state of not having undergone surface treatment with a surface treatment agent or the state of having undergone surface treatment with a surface treatment agent.

[0055] The spherical nanofiller used in this invention can be a spherical nanofiller that has undergone hydrophobic treatment using a surface treatment agent. The hydrophobic treatment can be performed before or after surface treatment using a silane coupling material represented by formula (1). Alternatively, the hydrophobicated spherical nanofiller can be a spherical nanofiller that has not undergone surface treatment using a silane coupling material represented by formula (1). By including the hydrophobicated spherical nanofiller, in addition to the sliding effect generated when an external force is applied, the hydrophilic interaction between the polymerizable monomer and the filler can be weakened, preventing damage to the fluidity of the paste when an external force is applied, and improving the fluidity of the paste.

[0056] The dental curing composition of the present invention may contain spherical nanofillers as inorganic fillers that have been surface-treated with a silane coupling material represented by formula (1). The compositional ratio of the surface-treated spherical nanofillers treated with the silane coupling material represented by formula (1) in the dental curing composition of the present invention is not particularly limited. When the dental curing composition does not contain a polymerization initiator, it may be set to 1-15% by weight of the total dental curing composition, or 1-5% by weight. When the dental curing composition contains a polymerization initiator, it may be set to 1-15% by weight of the dental curing composition after removing the polymerization initiator, or 1-5% by weight. That is, when the dental curing composition does not contain a polymerization initiator, it may be set to 1-15 parts by weight, or 1-5 parts by weight, relative to 100 parts by weight of the total dental curing composition; when the dental curing composition contains a polymerization initiator, it may be set to 1-15 parts by weight, or 1-5 parts by weight, relative to 100 parts by weight of the dental curing composition after removing the polymerization initiator. At concentrations less than 1% by weight, the fluidity of the paste sometimes deteriorates. Additionally, at concentrations greater than 15% by weight, the excipient properties of the paste sometimes deteriorate.

[0057] When the dental curing composition of the present invention contains the silane coupling material represented by formula (1) itself, the composition ratio of the spherical nanofiller in the dental curing composition of the present invention that has not been surface-treated with the silane coupling material represented by formula (1) is not particularly limited. When the dental curing composition does not contain a polymerization initiator, it can be set to 1 to 14% by weight of the total dental curing composition, or 1 to 5% by weight. When the dental curing composition contains a polymerization initiator, it can be set to 1 to 14% by weight of the dental curing composition after removing the polymerization initiator, or 1 to 5% by weight. That is, when the dental curing composition does not contain a polymerization initiator, it can be set to 1 to 14 parts by weight or 1 to 5 parts by weight relative to 100 parts by weight of the total dental curing composition. When the dental curing composition contains a polymerization initiator, it can be set to 1 to 14 parts by weight or 1 to 5 parts by weight relative to 100 parts by weight of the dental curing composition after removing the polymerization initiator. At concentrations less than 1% by weight, the fluidity of the paste sometimes deteriorates. Additionally, at concentrations greater than 14% by weight, the excipient properties of the paste sometimes deteriorate.

[0058] Spherical nanofillers do not necessarily have to be manufactured or obtained in the form of single particles. As long as their average particle size and composition ratio are within the above range, they can also be obtained by mixing two or more spherical nanofillers with different average particle sizes and / or composition ratios.

[0059] In particular, spherical nanofillers that have been surface-treated using both the silane coupling material represented by formula (1) and a surface treatment agent other than the silane coupling material represented by formula (1) are also effective.

[0060] The dental curing composition of the present invention may, in addition to comprising an inorganic filler surface-treated with a silane coupling material represented by formula (1), also comprise spherical nanofillers not surface-treated with a silane coupling material represented by formula (1) as other fillers described later. In the case where the dental curing composition of the present invention does not contain the silane coupling material represented by formula (1) itself, it may, in addition to comprising an inorganic filler surface-treated with a silane coupling material represented by formula (1), also comprise spherical nanofillers not surface-treated with a silane coupling material represented by formula (1) as other fillers described later.

[0061] There are no particular restrictions on the shape of inorganic fillers; they can be pulverized inorganic fillers. Being pulverized allows for the imparting of shape-enhancing properties to the paste. Pulverized inorganic fillers are mechanically pulverized inorganic fillers and can have shapes with arbitrary angles.

[0062] The average particle size of the fragmented inorganic filler used in this invention can be set to 0.01–100 μm, and from the viewpoint of mechanical strength, it can be set to 0.01–20 μm or 0.01–10 μm. When the average particle size is less than 0.01 μm, the specific surface area of ​​the fragmented inorganic filler increases, and sometimes the fluidity of the paste decreases. On the other hand, when the average particle size is greater than 100 μm, the dispersibility of the fragmented inorganic filler in the dental curing composition deteriorates, and sometimes it is impossible to produce a uniform paste.

[0063] The fragmented inorganic filler used in this invention can be a fragmented inorganic filler that has undergone hydrophobic treatment using a surface treatment agent. The hydrophobic treatment can be performed before or after surface treatment using a silane coupling material represented by formula (1). Alternatively, the hydrophobicated fragmented inorganic filler can be a fragmented inorganic filler that has not undergone surface treatment using a silane coupling material represented by formula (1). By including a hydrophobicated fragmented inorganic filler, the formability of the paste can be improved, and the mechanical strength of the cured dental curing composition can be improved.

[0064] The dental curing composition of the present invention may contain a fragmented inorganic filler as an inorganic filler that has been surface-treated with a silane coupling material represented by formula (1). The composition ratio of the surface-treated fragmented inorganic filler treated with a silane coupling material represented by formula (1) in the dental curing composition of the present invention is not particularly limited. When the dental curing composition does not contain a polymerization initiator, it may be set to 10-60% by weight of the total dental curing composition, or 20-50% by weight. When the dental curing composition contains a polymerization initiator, it may be set to 10-60% by weight of the dental curing composition after removing the polymerization initiator, or 20-50% by weight. That is, when the dental curing composition does not contain a polymerization initiator, the content can be set to 10-60 parts by weight or 20-50 parts by weight relative to 100 parts by weight of the total dental curing composition. When the dental curing composition contains a polymerization initiator, the content can be set to 10-60 parts by weight or 20-50 parts by weight relative to 100 parts by weight of the dental curing composition after removing the polymerization initiator. At a content of less than 10% by weight, the mechanical strength of the cured product may sometimes decrease. Furthermore, at a content of more than 60% by weight, the workability may sometimes deteriorate due to the excessively high viscosity of the adjusted paste.

[0065] When the dental curing composition of the present invention contains the silane coupling material represented by formula (1) itself, the composition ratio of the fragmented inorganic filler in the dental curing composition of the present invention that has not been surface-treated using the silane coupling material represented by formula (1) is not particularly limited. When the dental curing composition does not contain a polymerization initiator, it can be set to 10 to 50% by weight of the total dental curing composition, or 20 to 40% by weight. When the dental curing composition contains a polymerization initiator, it can be set to 10 to 50% by weight of the dental curing composition after removing the polymerization initiator, or 20 to 40% by weight. That is, when the dental curing composition does not contain a polymerization initiator, it can be set to 10 to 50 parts by weight or 20 to 40 parts by weight relative to 100 parts by weight of the total dental curing composition. When the dental curing composition contains a polymerization initiator, it can be set to 10 to 50 parts by weight or 20 to 40 parts by weight relative to 100 parts by weight of the dental curing composition after removing the polymerization initiator. At concentrations below 10% by weight, the mechanical strength of the cured product sometimes decreases. Additionally, at concentrations above 50% by weight, the paste becomes too viscous, sometimes resulting in poor workability.

[0066] Crushed inorganic fillers do not necessarily have to be manufactured or obtained in the form of single particles. As long as their average particle size and composition ratio are within the above range, they can also be obtained by mixing two or more crushed inorganic fillers with different average particle sizes and / or composition ratios.

[0067] In particular, it is also effective to use silane coupling materials represented by formula (1) and surface treatment agents other than silane coupling materials represented by formula (1) for surface treatment.

[0068] By incorporating fragmented inorganic fillers, the cured product exhibits excellent mechanical strength and excellent shapeability. Furthermore, by combining fragmented inorganic fillers with spherical nanofillers, the dental curing composition of the present invention also achieves excellent flowability. For pastes with high inorganic filler filling rates, for example, when using a large amount of fragmented inorganic fillers, the fragmented inorganic fillers hook and interfere with each other when force is applied to the paste, thus increasing the paste's viscosity and impairing its flowability.

[0069] The dental curing composition of the present invention may, in addition to comprising an inorganic filler surface-treated with a silane coupling material represented by formula (1), also include a fragmented inorganic filler not surface-treated with a silane coupling material represented by formula (1) as other fillers described later. In the case where the dental curing composition of the present invention does not contain the silane coupling material represented by formula (1) itself, it may, in addition to comprising an inorganic filler surface-treated with a silane coupling material represented by formula (1), also include a fragmented inorganic filler not surface-treated with a silane coupling material represented by formula (1) as other fillers described later.

[0070] The shape of the inorganic filler is not particularly limited, and it can be an aggregated inorganic filler. When the inorganic filler is an aggregate, the average particle size described later refers to the average particle size of the aggregate. Aggregated inorganic fillers refer to fillers obtained by granulating nano-sized inorganic fillers through processes such as spray drying. The agglomeration force of the granulated fillers can be expected to improve the mechanical strength of the cured dental composition.

[0071] The average particle size of the agglomerated inorganic filler used in this invention can be set to 0.01–100 μm, and from the viewpoint of mechanical strength, it can be set to 0.01–20 μm or 0.01–10 μm. When the average particle size is less than 0.01 μm, the specific surface area of ​​the agglomerated inorganic filler sometimes increases, and the fluidity of the paste decreases. On the other hand, when the average particle size is greater than 100 μm, the dispersibility of the agglomerated inorganic filler in the dental curing composition deteriorates, and sometimes it is impossible to produce a uniform paste.

[0072] The aggregated inorganic filler used in this invention can be an aggregated inorganic filler that has undergone hydrophobic treatment using a surface treatment agent. The hydrophobic treatment can be performed before or after surface treatment using a silane coupling material represented by formula (1). Alternatively, the hydrophobicated aggregated inorganic filler can be an aggregated inorganic filler that has not undergone surface treatment using a silane coupling material represented by formula (1). By including a hydrophobicated aggregated inorganic filler, the formability can be improved, and the mechanical strength of the cured dental curing composition can be increased.

[0073] The dental curing composition of the present invention may contain aggregated inorganic filler as an inorganic filler that has been surface-treated with a silane coupling material represented by formula (1). The composition ratio of the surface-treated aggregated inorganic filler treated with a silane coupling material represented by formula (1) in the dental curing composition of the present invention is not particularly limited. When the dental curing composition does not contain a polymerization initiator, it may be set to 10-60% by weight of the total dental curing composition, or 20-50% by weight. When the dental curing composition contains a polymerization initiator, it may be set to 10-60% by weight of the dental curing composition after removing the polymerization initiator, or 20-50% by weight. That is, when the dental curing composition does not contain a polymerization initiator, the content can be set to 10-60 parts by weight or 20-50 parts by weight relative to 100 parts by weight of the total dental curing composition. When the dental curing composition contains a polymerization initiator, the content can be set to 10-60 parts by weight or 20-50 parts by weight relative to 100 parts by weight of the dental curing composition after removing the polymerization initiator. At a content of less than 10% by weight, the mechanical strength of the cured product may sometimes decrease. Furthermore, at a content of more than 60% by weight, the workability may sometimes deteriorate due to the excessively high viscosity of the adjusted paste.

[0074] The aggregated inorganic filler of the present invention is a zirconium silicate composed of "SiO2 / ZrO2". Its composition ratio is not particularly limited and can be set to "SiO2 / ZrO2 = 50 / 50 to 99 / 1" or "SiO2 / ZrO2 = 70 / 30 to 90 / 10". When the ZrO2 content is below 1, the mechanical strength of the cured product sometimes decreases. Furthermore, when the ZrO2 content is above 50, the transparency of the dental curing composition is sometimes unattainable.

[0075] When the dental curing composition of the present invention contains the silane coupling material represented by formula (1) itself, the composition ratio of the aggregated inorganic filler in the dental curing composition of the present invention that has not been surface-treated using the silane coupling material represented by formula (1) is not particularly limited. When the dental curing composition does not contain a polymerization initiator, it can be set to 9 to 55% by weight of the total dental curing composition, or 19 to 47% by weight. When the dental curing composition contains a polymerization initiator, it can be set to 9 to 55% by weight of the dental curing composition after removing the polymerization initiator, or 19 to 47% by weight of the dental curing composition after removing the polymerization initiator. That is, when the dental curing composition does not contain a polymerization initiator, the content can be set to 9 to 55 parts by weight or 19 to 47 parts by weight relative to 100 parts by weight of the total dental curing composition. When the dental curing composition contains a polymerization initiator, the content can be set to 9 to 55 parts by weight or 19 to 47 parts by weight relative to 100 parts by weight of the dental curing composition after removing the polymerization initiator. At a content of less than 9% by weight, the mechanical strength of the cured product may sometimes decrease. Furthermore, at a content greater than 55% by weight, the workability may sometimes deteriorate due to excessively high viscosity of the paste.

[0076] Aggregated inorganic fillers do not necessarily have to be manufactured or obtained in the form of single particles. As long as their average particle size and composition ratio are within the above range, they can also be aggregated inorganic fillers obtained by mixing two or more inorganic fillers with different average particle sizes and / or compositions.

[0077] In particular, it is also effective to use agglomerated inorganic fillers that have been surface-treated with silane coupling materials represented by formula (1) and surface treatment agents other than silane coupling materials represented by formula (1).

[0078] By incorporating aggregated inorganic fillers, dental curable compositions with excellent mechanical strength and excellent paste-like properties can be produced. Furthermore, by combining aggregated inorganic fillers with spherical nanofillers, excellent paste-like flowability of the dental curable compositions of the present invention can also be obtained. For pastes with high inorganic filler filling rates, for example, when using a large amount of aggregated inorganic fillers, the aggregated inorganic fillers hook and interfere with each other when force is applied to the paste, thus increasing the paste's viscosity and sometimes impairing its flowability.

[0079] The dental curing composition of the present invention may, in addition to comprising an inorganic filler surface-treated with a silane coupling material represented by formula (1), also comprise an aggregated inorganic filler not surface-treated with a silane coupling material represented by formula (1) as other fillers described later. In the case where the dental curing composition of the present invention does not comprise the silane coupling material represented by formula (1) itself, it may, in addition to comprising an inorganic filler surface-treated with a silane coupling material represented by formula (1), also comprise an aggregated inorganic filler not surface-treated with a silane coupling material represented by formula (1) as other fillers described later.

[0080] [Other fillers]

[0081] The dental curing composition of the present invention can be combined with various known fillers other than inorganic fillers that have been surface-treated using silane coupling materials represented by formula (1) as needed. Other fillers used in the present invention include: the aforementioned inorganic fillers without surface treatment, the aforementioned inorganic fillers without surface treatment using silane coupling materials represented by the chemical structural formula of formula (1), the aforementioned inorganic fillers that have been surface-treated using surface treatment agents other than silane coupling materials represented by formula (1), organic fillers, organic-inorganic composite fillers, etc.

[0082] In the case where the dental curing composition contains the silane coupling material represented by formula (1) itself, other fillers may be incorporated into the dental curing composition after the surface treatment using the silane coupling material represented by formula (1) is completed.

[0083] Inorganic fillers that have undergone surface treatment using a surface treatment agent other than the silane coupling material represented by formula (1) can be inorganic fillers that have undergone surface treatment using only a surface treatment agent other than the silane coupling material represented by formula (1). Examples of such surface treatments include surface treatment using 3-methacryloyloxypropyltrimethoxysilane, surface treatment using 8-methacryloyloxyoctyltrimethoxysilane, and surface treatment using titanium acetylacetonate. By using two or more surface treatment agents, including both surface treatment agents other than the silane coupling material represented by formula (1) and surface treatment agents other than the silane coupling material represented by formula (1), the polymerizability of the polymerizable monomers, the dispersibility of the fillers, the workability and excipient properties of the paste, the stability of the paste, and the mechanical strength after curing, etc., of the dental curable composition as a whole, can be freely adjusted.

[0084] For inorganic fillers that have been surface-treated with a surface treatment agent other than the silane coupling material represented by formula (1), when the dental curing composition does not contain a polymerization initiator, it can be set to 1 to 50% by weight of the total dental curing composition, or 10 to 40% by weight. That is, relative to 100 parts by weight of the total dental curing composition, it can be set to 1 to 50 parts by weight, or 10 to 40 parts by weight. If it is less than 1% by weight, the workability of the paste may deteriorate, and when it is greater than 50% by weight, the mechanical strength after curing may decrease. In addition, when the dental curing composition contains a polymerization initiator, it can be set to 20 to 40% by weight of the dental curing composition after removing the polymerization initiator. That is, relative to 100 parts by weight of the dental curing composition after removing the polymerization initiator, it can be set to 20 to 40 parts by weight. If it is less than 20% by weight, the workability of the paste may deteriorate, and when it is greater than 40% by weight, the mechanical strength after curing may decrease.

[0085] Examples of organic fillers include: elastomers such as polyvinyl acetate, polyvinyl alcohol, and styrene-butadiene rubber; non-crosslinked (meth)acrylate polymers, such as polymethyl methacrylate (PMMA), polyethyl methacrylate, polypropyl methacrylate, and polybutyl methacrylate, which are homopolymers of monofunctional (meth)acrylate polymeric monomers; crosslinked (meth)acrylate polymers obtained by copolymerizing monofunctional (meth)acrylate polymeric monomers with polymeric monomers having two or more functional groups; polyvinyl acetate; polyethylene glycol; polypropylene glycol; polyvinyl alcohol, etc., but not limited to these.

[0086] As organic-inorganic composite fillers, examples include fillers obtained by surface polymerization coating of fillers using polymerizable monomers, fillers obtained by mixing / polymerizing fillers with polymerizable monomers and then pulverizing them into appropriate particle sizes, or fillers obtained by pre-dispersing fillers in polymerizable monomers for emulsion polymerization or suspension polymerization. There are no limitations on these.

[0087] These organic fillers and organic-inorganic composite fillers can be surface-treated organic fillers and organic-inorganic composite fillers, or they can be untreated organic fillers and organic-inorganic composite fillers.

[0088] The dental curing composition of the present invention may be a dental curing composition that does not contain inorganic fillers that have not been surface-treated using a silane coupling material represented by formula (1). The dental curing composition of the present invention may not contain fillers other than inorganic fillers that have been surface-treated using a silane coupling material represented by formula (1). The dental curing composition of the present invention may not contain untreated inorganic fillers. The dental curing composition of the present invention may not contain untreated fillers.

[0089] [Free radical polymerizable monomers]

[0090] For the free radical polymerizable monomer incorporated into a specific dental curing composition containing the inorganic filler of the present invention, when the dental curing composition does not contain a polymerization initiator, it can be set to 10-60% by weight of the total dental curing composition, or 15-30% by weight; when the dental curing composition contains a polymerization initiator, it can be set to 10-60% by weight of the dental curing composition after removing the polymerization initiator, or 15-30% by weight. That is, when the dental curing composition does not contain a polymerization initiator, it can be set to 10-60 parts by weight or 15-30 parts by weight relative to 100 parts by weight of the total dental curing composition; when the dental curing composition contains a polymerization initiator, it can be set to 10-60 parts by weight or 15-30 parts by weight relative to 100 parts by weight of the dental curing composition after removing the polymerization initiator. If less than 10% by weight, the dental curing composition is too viscous and may impair the workability of the paste; when greater than 60% by weight, the mechanical strength of the cured dental curing composition may decrease.

[0091] The free radical polymerizable monomers used in the dental curing compositions of the present invention can be freely used free radical polymerizable monomers commonly used in the dental field, and can have urethane bonds and hydrogen bonds on their molecular backbone. This is to effectively form hydrogen bonds with the silane coupling materials used in the present invention. Examples of monomers that do not have urethane bonds and hydrogen bonds include: phenoxyethyl acrylate, methyl methacrylate, tetrahydrofurfuryl acrylate, triethylene glycol diacrylate, trimethylolpropane triacrylate, dipentaerythritol hexaacrylate, bisphenol A diethoxylated diacrylate, etc.

[0092] The number of functional groups in the free radical polymerizable monomers used in this invention can be 2 to 9. In the case of monofunctionality, cross-linked structures cannot be formed, and sometimes sufficient mechanical strength cannot be imparted to the dental curing composition. On the other hand, in the case of 10 or more functional groups, the density of the cross-linked structure becomes too high, sometimes causing the dental curing composition to become brittle. In this invention, the functionality of the free radical polymerizable monomer refers to the number of polymerizable groups such as (meth)acryloyl groups.

[0093] The free radical polymerizable monomer can be a monomer containing a urethane bond. Regarding the specific amount of the free radical polymerizable monomer containing a urethane bond, when the dental curing composition does not contain a polymerization initiator, it can be set to 10-50% by weight of the total dental curing composition, or 15-30% by weight. When the dental curing composition contains a polymerization initiator, it can be set to 10-50% by weight of the dental curing composition after removing the polymerization initiator, or 15-30% by weight. That is, when the dental curing composition does not contain a polymerization initiator, relative to 100 parts by weight of the total dental curing composition, it can be set to 10-50 parts by weight, or 15-30 parts by weight; when the dental curing composition contains a polymerization initiator, relative to 100 parts by weight of the dental curing composition after removing the polymerization initiator, it can be set to 10-50 parts by weight, or 15-30 parts by weight. If the percentage is less than 10% by weight, the mechanical strength of the cured dental curing composition may decrease. If the percentage is greater than 50% by weight, the dental curing composition becomes too viscous, potentially impairing the workability of the paste. In this invention, a urethane bond refers to a bond having a -NH-C(=O)-O- group. Examples of such free radical polymerizable monomers include di(meth)acrylates with urethane bonds that are difunctional or higher, derived from adducts of hydroxyl-containing polymerizable monomers such as 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, and 3-chloro-2-hydroxypropyl (meth)acrylate with diisocyanate compounds such as methylcyclohexane diisocyanate, methylene bis(4-cyclohexyl)isocyanate, hexamethylene diisocyanate, trimethylhexamethylene diisocyanate, isophorone diisocyanate, methyl methylbenzene diisocyanate, and 4,4-diphenylmethane diisocyanate.

[0094] The free radical polymerizable monomer can be a monomer containing hydrogen bonds. Regarding the specific amount of a free radical polymerizable monomer containing hydrogen bonds, if the dental curing composition does not contain a polymerization initiator, it can be set to 1-20% by weight of the total dental curing composition, or 1-10% by weight. If the dental curing composition contains a polymerization initiator, it can be set to 1-20% by weight of the dental curing composition after removing the polymerization initiator, or 1-10% by weight. That is, if the dental curing composition does not contain a polymerization initiator, it can be set to 1-20 parts by weight, or 1-10 parts by weight, relative to 100 parts by weight of the total dental curing composition; if the dental curing composition contains a polymerization initiator, it can be set to 1-20 parts by weight, or 1-10 parts by weight, relative to 100 parts by weight of the dental curing composition after removing the polymerization initiator. If it is less than 1% by weight, the dental curing composition will have excessive viscosity, which may impair the workability of the paste. When the content exceeds 20% by weight, the mechanical strength of the cured dental curing composition may decrease. Examples of such free radical polymerizable monomers include: 2-hydroxy-1,3-dimethacryloyloxypropane, 4-hydroxybutyl acrylate, 2-hydroxyethyl acrylate, 2-hydroxypropyl acrylate, 2-hydroxyethyl methacrylate, 2-hydroxypropyl methacrylate, 2-hydroxy-3-phenoxypropyl acrylate, 2-acryloyloxyethyl-2-hydroxyethyl phthalate, and 2-acryloyloxyethyl hexahydrophthalate.

[0095] Free radical polymerizable monomers can be monomers having one or more hydroxyl groups and more than two functional polymerizable groups. In this invention, more than two functional polymerizable groups refer to the number of polymerizable groups such as (meth)acryloyl groups. Examples of such free radical polymerizable monomers include: 2-hydroxy-1,3-dimethacryloyloxypropane, 2-hydroxy-1,3-diacryloyloxypropane, 2-hydroxy-3-acryloyloxypropyl methacrylate, 2-acryloyloxyethyl phthalate, tetrahydrophthalate acryloyloxyethyl monomethyl ester, etc. By having one or more hydroxyl groups and more than two functional polymerizable groups, suitable dispersibility of the paste can be obtained, and high mechanical strength after curing can be achieved.

[0096] As a free radical polymerizable monomer having one or more hydroxyl groups and more than one difunctional polymerizable group, it can be a monomer represented by formula (2). For the monomer represented by formula (2), when the dental curing composition does not contain a polymerization initiator, it can be set to 1 to 20% by weight of the total dental curing composition, or 1 to 10% by weight; when the dental curing composition contains a polymerization initiator, it can be set to 1 to 20% by weight of the dental curing composition after removing the polymerization initiator, or 1 to 10% by weight of the dental curing composition after removing the polymerization initiator. That is, when the dental curing composition does not contain a polymerization initiator, it can be set to 1 to 20 parts by weight, or 1 to 10 parts by weight, relative to 100 parts by weight of the total dental curing composition; when the dental curing composition contains a polymerization initiator, it can be set to 1 to 20 parts by weight, or 1 to 10 parts by weight of the dental curing composition after removing the polymerization initiator. If the content is less than 1% by weight, the dental curing composition will have excessive viscosity, which may impair the workability of the paste. When it is greater than 20% by weight, the mechanical strength of the dental curing composition may decrease. By using the optimal content, hydrogen bonds are formed with the amide bonds contained in the silane coupling material, thereby improving the mechanical strength of the cured body.

[0097]

[0098] When the dental curing composition of the present invention comprises the silane coupling material represented by formula (1) itself, the weight ratio of the silane coupling material represented by formula (1) to the free radical polymerizable monomer having the compound represented by formula (2) can be set in the range of 1:0.5 to 1:20. When the weight ratio of the free radical polymerizable monomer having the compound represented by formula (2) to the silane coupling material represented by formula (1) is less than 1:0.5, the dental curing composition has excessive viscosity, which may impair the workability of the paste; when it is greater than 1:20, the mechanical strength of the dental curing composition may decrease.

[0099] [Polymerization initiator]

[0100] There are no particular limitations on the polymerization initiator used in this invention, and any known free radical generating material can be used without restriction. Polymerization initiators are generally classified into: polymerization initiators that initiate polymerization by heating (thermal polymerization initiators), polymerization initiators that initiate polymerization by light irradiation (photopolymerization initiators), and polymerization initiators that initiate polymerization by mixing a composition of two forms (chemical polymerization initiators). From the viewpoint of the mechanical strength after curing, a thermal polymerization initiator is preferred as the polymerization initiator of this invention.

[0101] Organic peroxides are preferred as thermal polymerization initiators. Examples include: benzoyl peroxide, p-chlorobenzoyl peroxide, 1,1-bis(tert-butylperoxy)cyclohexane, 2,4-dichlorobenzoyl peroxide, acetyl peroxide, lauroyl peroxide, tert-butyl peroxide, cumene hydroperoxide, 2,5-dimethylhexane, 2,5-dihydroperoxide, methyl ethyl ketone peroxide, and tert-butyl peroxide.

[0102] The thermal polymerization initiator of the present invention can be selected from, for example, thermal polymerization initiators commonly used in industry that have a specific 10-hour half-life temperature.

[0103] The 10-hour half-life temperature of the thermal polymerization initiator of the present invention is 50–200°C, and from the viewpoint of mechanical strength, it can be set to 90–170°C. By setting an appropriate range of 10-hour half-life temperature, even when using high-viscosity free-radical polymerizable monomers, the polymerization rate can be increased, and the mechanical strength of the resulting cured product is improved. When the 10-hour half-life temperature is below 50°C, a sufficient polymerization rate cannot be obtained when using high-viscosity polymerizable monomers, and the mechanical strength may decrease. When the temperature is above 200°C, due to heat-induced deterioration, a decrease in the mechanical strength of the cured product and yellowing may occur. The 10-hour half-life temperature of the present invention refers to the temperature at which the half-life of the thermal polymerization initiator is 10 hours, and the half-life refers to the time it takes for the concentration of the thermal polymerization initiator to decrease to half of its initial value. Examples of thermal polymerization initiators with a 10-hour half-life temperature between 70°C and 170°C include: 1,1-bis(tert-butylperoxy)cyclohexane, 2,2-bis[4,4-bis(isobutylperoxy)cyclohexyl]propane, tert-butylperoxyisopropyl carbonate, tert-butyl dodecanoate peroxy, tert-butylperoxy(2-ethylhexyl) carbonate, bis(1-phenyl-1-methylethyl) peroxide, di-tert-butyl peroxide, and 2,5-dimethyl-2,5-di-(tert-butylperoxy)-hexyne-3.

[0104] Examples of photopolymerization initiators include: camphorquinone, diphenyl(2,4,6-trimethylbenzoyl)phosphine oxide, phenylbis(2,4,6-trimethylbenzoyl)phosphine oxide, naphthyl ethyl ketone, p-dimethoxybenzyl, p-dichlorobenzylacetyl, pentanedione, 1,2-phenanthrenequinone, 1,4-phenanthrenequinone, 3,4-phenanthrenequinone, 9,10-phenanthrenequinone, naphthylquinone, and other α-diketones; benzoin, benzoin methyl ether, benzoin ethyl ether, and other benzoin alkyl ethers; thioxanone, 2-chlorothioxanone, 2-methylthioxanone, 2-isopropylthioxanone, 2-methoxythioxanone, 2-hydroxythioxanone, 2,4-diethylthioxanone, etc.

[0105] Examples of chemical polymerization initiators include: redox polymerization catalyst systems composed of organic peroxides / amines or organic peroxides / amines / sulfinates, organic peroxides / amines / borates; polymerization catalyst systems such as organoboron compounds, perborates, permanganates, and persulfates that initiate polymerization by reacting with oxygen and water; and sulfinates, borates, and barbiturates can also initiate polymerization by coexisting with water and / or polymerizable monomers with acidic groups.

[0106] When specifically exemplifying organic peroxides, examples may include: benzoyl peroxide, p-chlorobenzoyl peroxide, 2,4-dichlorobenzoyl peroxide, acetyl peroxide, lauroyl peroxide, tert-butyl peroxide, cumene hydroperoxide, 2,5-dimethylhexane, 2,5-dihydroperoxide, methyl ethyl ketone peroxide, tert-butyl peroxide, etc., but are not limited to these. Furthermore, the above-mentioned organic peroxides may be used alone or in combination of several.

[0107] As amine compounds, secondary or tertiary amines in which the amino group is attached to an aryl group are preferred. Examples include, but are not limited to, N,N-dimethyl-p-toluidine, N,N-dimethylaniline, N-β-hydroxyethylaniline, N,N-di(β-hydroxyethyl)-aniline, N,N-di(β-hydroxyethyl)-p-toluidine, N-methylaniline, and N-methyl-p-toluidine. Furthermore, the above-mentioned amine compounds may be used alone or in combination of several.

[0108] As sulfinates, examples include sodium benzenesulfinate, lithium benzenesulfinate, and sodium p-toluenesulfinate, but these are not limited to. Furthermore, the above-mentioned sulfinates may be used alone or in combination of several.

[0109] Examples of borate compounds, when specifically exemplified, include sodium, lithium, potassium, and magnesium salts of trialkylphenylboron and trialkyl(p-fluorophenyl)boron (where the alkyl group is n-butyl, n-octyl, n-dodecyl, etc.), but are not limited to these. Furthermore, the above-mentioned borate compounds can be used alone or in combination of several. As barbiturates, specific examples include: barbituric acid, 1,3-dimethylbarbituric acid, 1,3-diphenylbarbituric acid, 1,5-dimethylbarbituric acid, 5-butylbarbituric acid, 5-ethylbarbituric acid, 5-isopropylbarbituric acid, 5-cyclohexylbarbituric acid, 1,3,5-trimethylbarbituric acid, 1,3-dimethyl-5-ethylbarbituric acid, 1,3-dimethyl-n-butylbarbituric acid, 1,3-dimethyl-5-isobutylbarbituric acid, 1,3-dimethylbarbituric acid, 1 3-Dimethyl-5-cyclopentylbarbituric acid, 1,3-dimethyl-5-cyclohexylbarbituric acid, 1,3-dimethyl-5-phenylbarbituric acid, 1-cyclohexyl-5-ethylbarbituric acid, 1-benzyl-5-phenylbarbituric acid, and thiobarbituric acids and their salts (especially alkali metal or alkaline earth metal salts), such as sodium 5-butylbarbiturate, sodium 1,3,5-trimethylbarbiturate, calcium 1,3,5-trimethylbarbiturate, and sodium 1-cyclohexyl-5-ethylbarbiturate, etc., but not limited thereto. Furthermore, the above-mentioned barbiturates can be used alone or in combination of several.

[0110] Among these chemical polymerization initiators, a combination of organic peroxides and tertiary amines can be used.

[0111] These polymerization initiating materials, regardless of the polymerization method, can be used alone or in combination of two or more. Furthermore, even if these polymerization initiating materials undergo secondary processing such as encapsulation into microcapsules as needed, there are no problems. The dental curing composition of the present invention may contain only a thermal polymerization initiating material as the polymerization initiating material. The dental curing composition of the present invention may contain only a photopolymerization initiating material as the polymerization initiating material.

[0112] The content of the polymerization initiator material used in this invention can be appropriately selected according to the application. It can be set to a range of 0.01 to 10 parts by weight relative to 100 parts by weight of the free radical polymerizable monomer, or a range of 0.1 to 5 parts by weight. When there is too much polymerization initiator, cracks are easily generated during the manufacture of the cured resin for dental cutting, sometimes making manufacturing difficult. When there is too little polymerization initiator, sufficient effect cannot be obtained, and mechanical strength is reduced.

[0113] The dental curing composition of the present invention can be formulated with various known additives as needed. Examples of additives used in the present invention include: polymerization inhibitors, chain transfer materials, coloring materials, anti-discoloration materials, fluorescent materials, ultraviolet-absorbing materials, and antibacterial materials. The dental curing composition of the present invention may contain only one or more additives selected from polymerization inhibitors, chain transfer materials, coloring materials, anti-discoloration materials, fluorescent materials, ultraviolet-absorbing materials, and antibacterial materials.

[0114] For the cured body of the dental curing composition of the present invention, the flexural strength after being stored in water at 37°C for one week can be 300 MPa or more. By achieving a flexural strength of 300 MPa or more after being stored in water at 37°C for one week, a dental curing composition with excellent processability and durability for complex shapes can be provided. As a method for determining the flexural strength, it can be measured using a universal testing machine (manufactured by Instron Corporation) according to ISO 6872 at a crosshead speed of 1 mm / min.

[0115] For the cured body of the dental curing composition of the present invention, the flexural modulus after storage in water at 37°C for one week can be 20 GPa or higher. By achieving a flexural modulus of 20 GPa or higher after storage in water at 37°C for one week, a dental curing composition with excellent processability and durability for complex shapes can be provided. The flexural modulus can be determined using a universal testing machine (manufactured by Instron Corporation) according to ISO 6872 at a crosshead speed of 1 mm / min.

[0116] The dental curing composition of the present invention can be used, for example, in the manufacture of resin cured bodies for dental cutting, the manufacture of dental composite resins, and dental curing compositions for 3D printing.

[0117] [Example]

[0118] The embodiments of the present invention will be described in detail below, but the present invention is not limited to these embodiments. The abbreviations, physical properties, and test methods of the components in the embodiments and comparative examples are as follows.

[0119] [Inorganic packing]

[0120] ZSF: Aggregated zirconium silicate (d 50 (2μm).

[0121] GM32087: Fragmented Strontium Aluminum Borosilicate Glass (d 50 (0.4μm, manufactured by SCHOTT company).

[0122] Aerosil R-7200: Amorphous, non-crystalline silica (primary particle size: 12nm, manufactured by Aerosil company, Japan).

[0123] Aerosil OX-50: Amorphous, non-crystalline silica (primary particle size: 40 nm, manufactured by Aerosil company, Japan).

[0124] Admanano YC100C-SM2: Spherical amorphous silica (primary particle size: 100nm, manufactured by Admatechs company).

[0125] [Surface treatment agent]

[0126] <Silane coupling materials represented by formula (1)>

[0127] X-12-1370: N-(3-trimethoxysilyl)propyl)methacrylamide (molecular weight 247, manufactured by Shin-Etsu Chemical Co., Ltd.).

[0128] <Silane coupling materials other than those represented by formula (1)>

[0129] KBM-503: 3-Methacryloxypropyltrimethoxysilane (molecular weight 248, manufactured by Shin-Etsu Chemical Co., Ltd.)

[0130] KBM-502: 3-Methacryloxypropylmethyldimethoxysilane (molecular weight 232, manufactured by Shin-Etsu Chemical Industry Co., Ltd.)

[0131] KBM-5803: 8-Methacryloxyoctyltrimethoxysilane (molecular weight 319, manufactured by Shin-Etsu Chemical Co., Ltd.)

[0132] TC-100: Titanium acetylacetonate (manufactured by Matsumoto Fine Chemical Co., Ltd.).

[0133] TC-401: Titanium tetraacetylacetone (manufactured by Matsumoto Fine Chemical Co., Ltd.).

[0134] TC-750: Ethyl acetoacetate titanium (manufactured by Matsumoto Fine Chemical Co., Ltd.).

[0135] ZC-200: Zirconium octanoate compound (manufactured by Matsumoto Fine Chemical Co., Ltd.).

[0136] ZC-580: Ethyl acetozirconium (manufactured by Matsumoto Fine Chemical Co., Ltd.).

[0137] KBE-9103P: 3-[(1,3-dimethylbutylene)amino]propyltriethoxysilane (molecular weight 304, manufactured by Shin-Etsu Chemical Co., Ltd.).

[0138] X-12-1135: An organosiloxane containing a carboxyl group (manufactured by Shin-Etsu Chemical Co., Ltd.).

[0139] [Free radical polymerizable monomers]

[0140] <Free radical polymerizable monomers with carbamate bonds>

[0141] GENOMER 4267: Aliphatic urethane acrylate (viscosity 16000 mPa·s @ 60℃, Rahn company)

[0142] GENOMER 4247: Aliphatic carbamate methacrylate (viscosity 10000 mPa·s @ 25℃, Rahn company).

[0143] GENOMER 4425: Aliphatic urethane acrylate (viscosity 4500 mPa·s @ 25℃, Rahn company).

[0144] <Free radical polymerizable monomers with hydrogen bonds>

[0145] HEMA: 2-Hydroxyethyl methacrylate (viscosity: 7 mPa·s (20°C), manufactured by Mitsubishi Chemical Corporation).

[0146] M-600A: 2-Hydroxy-3-phenoxypropyl acrylate (viscosity: 150 mPa·s (25°C), manufactured by Kyoei Chemical Co., Ltd.).

[0147] Polymerizable monomers having one or more hydroxyl groups and more than one difunctional polymerizable group.

[0148] G-201P: 2-Hydroxy-3-Acryloyloxypropyl Methacrylate (Viscosity: 50 mPa·s, manufactured by Kyoei Chemical Co., Ltd.).

[0149] <Polymers represented by equation (2)>

[0150] NK Ester 701: 2-hydroxy-1,3-dimethylacryloyloxypropane (viscosity: 37 mPa·s (25°C), manufactured by Shin-Nakamura Chemical Industry Co., Ltd.).

[0151] <Other free radical polymerizable monomers>

[0152] 14EG: Polyethylene glycol dimethacrylate (viscosity: 60 mPa·s (25°C), manufactured by Kyoei Chemical Co., Ltd.).

[0153] BP-2EM: Bisphenol A EO (ethylene oxide) adduct dimethacrylate (viscosity: 1400 mPa·s (25°C), manufactured by Kyoei Chemical Co., Ltd.).

[0154] 3G: Triethylene glycol dimethacrylate (viscosity: 9 mPa·s (25°C), manufactured by Shin-Nakamura Chemical Industry Co., Ltd.).

[0155] [Polymerization initiator]

[0156] <Thermal polymerization initiator>

[0157] Perhexa C: 1,1-bis(tert-butylperoxy)cyclohexane (10-hour half-life temperature: 90.7°C, manufactured by Nippon Oil Co., Ltd.).

[0158] Perhexa V: n-Butyl-4,4-bis(tert-butylperoxy)valerate (10-hour half-life temperature: 104.5°C, manufactured by Nippon Oil Co., Ltd.).

[0159] Perhexyl D: Di-tert-hexyl peroxide (10-hour half-life temperature: 116.4°C, manufactured by Nippon Oil Co., Ltd.).

[0160] [other]

[0161] γ-Terpinene: γ-Terpinene (molecular weight: 136.4, manufactured by Tokyo Chemical Industry Co., Ltd.).

[0162] (Preparation of various surface-treatment inorganic fillers)

[0163] Surface treatment was performed using a surface treatment agent in the combination shown in Table 1, relative to 100g of untreated inorganic filler. Specifically, a surface treatment liquid (a substance obtained by pre-stirring the surface treatment agent, 6g of water, 6g of ethanol, and 0.1g of phosphoric acid in the amounts specified in Table 1) was added to 100g of untreated inorganic filler and stirred and mixed for 15 minutes. Subsequently, a heat treatment was performed at 115°C for 3 hours to obtain the heat-treated product.

[0164] The processing capacity of each inorganic packing is as follows.

[0165] [Table 1]

[0166]

[0167] (Preparation of resin-cured bodies for dental cutting)

[0168] The proportions of each component in each embodiment and comparative example are shown in Tables 2 and 3. The components shown in Tables 2 and 3 were mixed and degassed under reduced pressure to obtain a mixture (a dental curable composition). The mixture was filled into an aluminum mold, clamped with an aluminum plate, and subjected to vacuum decompression. It was then cured by hot pressing at 130°C for 3.5 minutes. Subsequently, a resin-cured body obtained by further heat treatment at 150°C for 8 hours was used as the dental cutting resin-cured body in mechanical strength tests.

[0169] (Method for determining the mechanical strength of resin-cured bodies for dental cutting)

[0170] Test pieces (19.0 × 4.0 × 1.2 mm) were cut from a dental cutting resin cured body, and their surfaces were smoothed using water-resistant abrasive paper (#2000). These pieces were then used as test specimens. The prepared test pieces were immersed in deionized water and stored at 37°C for 7 days. Subsequently, the flexural strength and flexural modulus were determined using a universal testing machine (Instron 5967, manufactured by Instron Corporation) according to ISO 6872 at a crosshead speed of 1 mm / min.

[0171] The test results of the prepared dental curing compositions are shown in Tables 2 to 7.

[0172] [Table 2]

[0173] (parts by weight)

[0174] [Table 3]

[0175] (parts by weight)

[0176]

[0177] [Table 4]

[0178] (parts by weight)

[0179]

[0180] [Table 5]

[0181] (parts by weight)

[0182]

[0183] [Table 6]

[0184] (parts by weight)

[0185]

[0186] [Table 7]

[0187] (parts by weight)

[0188] [Examples 1-52]

[0189] The dental curable compositions of Examples 1-52 were observed to exhibit high flexural strength and flexural modulus, and also demonstrated excellent mechanical strength.

[0190] [Comparative Examples 1-22]

[0191] The dental curing compositions of Comparative Examples 1 to 22 showed reduced mechanical strength because they did not contain inorganic fillers that had been surface-treated with X-12-1370.

[0192] Thus, compared to conventionally used dental curing compositions (Comparative Examples 1-22) employing silane coupling materials (such as KBM-503), the dental curing compositions prepared according to the present invention exhibit significantly higher flexural strength. According to the present invention, it is possible to provide dental curing compositions with high mechanical strength after curing, which is not achievable through existing technologies.

[0193] In this specification, even when a disclosed constituent element is described as either singular or plural, or as not limited to either singular or plural, the constituent element may be either singular or plural, unless otherwise interpreted in the context.

[0194] Although this disclosure has been described with reference to detailed embodiments, those skilled in the art will understand that various changes or modifications can be made based on the matters disclosed in this specification. Therefore, the scope of embodiments of this disclosure is intended to include any changes or modifications.

[0195] According to the present invention, a dental curable composition that can be obtained with high mechanical strength after curing can be provided.

Claims

1. A dental curing composition, wherein, The dental curable composition comprises a silane coupling material represented by formula (1) and / or an inorganic filler surface-treated with a silane coupling material represented by formula (1).

2. The dental curing composition according to claim 1, wherein, The dental curing composition comprises an inorganic filler that has been surface-treated using a silane coupling material represented by formula (1).

3. The dental curing composition according to claim 2, wherein, In the surface-treated inorganic filler, the amount of silane coupling material treated is 0.1 to 20 parts by weight relative to 100 parts by weight of the inorganic filler during surface treatment.

4. The dental curing composition according to claim 2, wherein, The amount of inorganic filler surface-treated with the silane coupling material represented by formula (1) is 1 to 90 parts by weight relative to 100 parts by weight of the dental curing composition as a whole.

5. The dental curing composition according to any one of claims 1 to 4, wherein, The dental curing composition further comprises a free radical polymerizable monomer and a polymerization initiator.

6. The dental curing composition according to claim 5, wherein, The dental curing composition further comprises an inorganic filler that has been surface-treated with a surface treatment agent other than the silane coupling material represented by formula (1).

7. The dental curing composition according to claim 5, wherein, Free radical polymerizable monomers have urethane bonds.

8. The dental curing composition according to claim 5, wherein, Free radical polymerizable monomers have one or more hydroxyl groups and more than one difunctional polymerizable group.

9. The dental curing composition according to claim 8, wherein, The dental curable composition has a monomer represented by formula (2) as a free radical polymerizable monomer.

10. The dental curing composition according to claim 9, wherein, The amount of free radical polymerizable monomer having the compound represented by formula (2) is 1 to 10 parts by weight relative to 100 parts by weight of the dental curing composition as a whole.

11. The dental curing composition according to claim 9, wherein, The weight ratio of the silane coupling material represented by formula (1) to the free radical polymerizable monomer having the compound represented by formula (2) is in the range of 1:0.5 to 1:

20.

12. The dental curing composition according to claim 2, wherein, The average particle size of the inorganic filler that has been surface-treated using the silane coupling material represented by formula (1) is 0.01 to 1 μm, and the inorganic filler that has been surface-treated using the silane coupling material represented by formula (1) is selected from one or more of the group consisting of spherical nanofillers, fragmented inorganic fillers and aggregated inorganic fillers.

13. The dental curing composition according to claim 12, wherein, The dental curing composition comprises an aggregated inorganic filler, wherein the aggregated inorganic filler is composed of SiO2: 50-99 wt% and ZrO2: 1-50 wt%.

14. The dental curing composition according to claim 5, wherein, The 10-hour half-life temperature of the polymerization initiator is between 70°C and 170°C.

15. The dental curing composition according to claim 5, wherein, The cured dental curing composition has a flexural strength of over 300 MPa after being stored in water at 37°C for one week.

16. The dental curing composition according to claim 5, wherein, The flexural modulus of the cured dental curing composition is above 20 GPa after being stored in water at 37°C for one week.

17. The dental curing composition according to claim 5, wherein, The dental curing composition is used in the manufacture of one or more of the following: dental cutting resin curing bodies, dental composite resins, and dental curing compositions for 3D printing.

18. An inorganic filler, wherein, The inorganic filler is an inorganic filler that has undergone surface treatment using a silane coupling material represented by formula (1).

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