JP2012087204A - Resin cured product, curable composition, and method for manufacturing resin cured product - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a resin cured product that still has a high transparency even with inorganic particles included therein, and is suitable for use as a dental material.SOLUTION: The resin cured product includes: a mother phase composed of an acrylic polymer that does not contain fluorine; a coating phase composed of an acrylic polymer that contains fluorine; and the inorganic particles. The coating phase and the inorganic particles are dispersed in the mother phase. The coating phase lies between the mother phase and at least a part of the whole of the inorganic particles.

Description

  The present invention relates to a cured resin, a curable composition used for the production of a cured resin, and a method for producing a cured resin.

  Silica (silicon dioxide), etc., as a material (dental material) used for the preparation of dental crown materials such as crowns and inlays, prosthetic materials, provisional restoration, and superstructures in implant treatment Resin cured products obtained by curing compositions containing inorganic particles, (meth) acrylate polymerizable monomers, polymerization initiators, and the like are widely used.

  Such resin cured products are required to have aesthetics, strength, durability and the like in order to replace natural teeth, and various materials have been proposed.

  For example, Patent Document 1 contains 20 to 70% by weight of an inorganic filler having an average particle size of 0.01 to 0.04 μm, or 1 to 40% by weight of glass powder having an average particle size of 0.1 to 5 μm. It is disclosed that a dental prosthesis such as an inlay and a crown can be obtained by cutting a dental resin material made of an acrylic resin polymer.

JP-A-10-323353

  However, the transparency of the conventional dental prosthesis as described in Patent Document 1 is insufficient. This is presumably because light is refracted at the interface between the acrylic resin polymer and the glass powder in the dental prosthesis. In particular, when a large amount of glass particles having a large particle size is used to improve the strength of a dental prosthesis, the transparency is greatly impaired.

  The present invention has been made in view of the above-mentioned reasons, and has a high transparency while containing inorganic particles, and is a cured resin suitable as a dental material, and a curing used for the production of the cured resin. It aims at providing the manufacturing method of an adhesive composition and resin hardened | cured material.

  The cured resin according to the present invention comprises a matrix composed of an acrylic polymer containing no fluorine, a coating phase composed of an acrylic polymer containing fluorine, and inorganic particles. The covering phase and the inorganic particles are dispersed in the phase, and the covering phase is interposed between at least a part of the entire inorganic particles and the matrix phase.

  In the cured resin according to the present invention, the first inorganic particles having an average particle diameter in the range of 0.2 to 50 μm and the average particle diameter in the range of 0.005 to 0.1 μm in the entire inorganic particles. It is preferable that the 2nd inorganic particle in exists.

  In the cured resin according to the present invention, the inorganic particles are preferably spherical.

  The cured resin according to the present invention is preferably a dental material.

  The curable composition according to the present invention contains an acrylic polymerizable monomer that does not contain fluorine, and composite particles, and the composite particles include inorganic particles and a coating covering the surfaces of the inorganic particles, The coating is made of an acrylic polymer containing fluorine.

The first method for producing a cured resin according to the present invention is as follows.
A step of preparing an intermediate composition containing an acrylic polymerizable monomer containing fluorine, an acrylic polymerizable monomer not containing fluorine, and inorganic particles;
A step of curing the intermediate composition and pulverizing the intermediate cured product thereby to produce composite particles;
A step of preparing a curable composition containing an acrylic polymerizable monomer not containing fluorine and the composite particles; and a step of curing the curable composition.

The method for producing the second cured resin according to the present invention is as follows.
A step of preparing an intermediate composition containing an acrylic polymerizable monomer containing fluorine, an acrylic polymerizable monomer containing no fluorine, and first inorganic particles having an average particle size in the range of 0.2 to 50 μm. ,
A step of curing the intermediate composition and pulverizing the intermediate cured product thereby to produce composite particles;
Preparing a curable composition containing a fluorine-free acrylic polymerizable monomer, the composite particles, and second inorganic particles having an average particle diameter in the range of 0.005 to 0.1 μm; and A step of curing the curable composition.

  In the method for producing a cured resin according to the present invention, the maximum particle size of the composite particles is preferably 250 μm or less.

  According to the present invention, a resin cured product having high transparency while containing inorganic particles and suitable as a dental material can be obtained.

  The cured resin product according to the present embodiment includes a matrix phase, a coating phase, and inorganic particles. The coating phase and the inorganic particles are dispersed in the matrix phase, and the coating phase is interposed between at least a part of the entire inorganic particles and the matrix phase.

  The parent phase is composed of an acrylic polymer that does not contain fluorine. Examples of the acrylic polymer not containing fluorine include a polymer of an appropriate acrylic polymerizable monomer not containing fluorine. Known acrylic polymerizable monomers that do not contain fluorine include (meth) acrylate monomers, urethane (meth) acrylate monomers, and (meth) acrylate monomers containing a bisphenol A skeleton, which are generally used for dental applications. The compound of this is mentioned. Specific examples of the acrylic polymerizable monomer not containing fluorine include methyl (meth) acrylate, 2-hydroxyethyl (meth) acrylate, triethylene glycol di (meth) acrylate, di (phenylglycidyl ether (meth) acrylate)- Hexamethylene diurethane, di-2-methacryloxyethyl-2,2,4-trimethylhexamethylene diurethane (UDMA), 2,2-bis (4- (3-methacryloyloxy-2-hydroxypropoxy) phenyl) propane And compounds such as (Bis-GMA) and trimethylolpropane tri (meth) acrylate. Among these compounds, only one type may be used or a plurality of types may be used in combination.

  The inorganic particles (inorganic filler) may be particles made of an appropriate inorganic material that can be used as a dental material. Specific examples of the inorganic particles include silica particles, alumina particles, zirconia particles, and particles made of a composite ceramic in which at least one of alumina and zirconia is combined with silica.

  The content of the entire inorganic particles in the cured resin is not particularly limited, but is preferably 20% by mass or more based on the total amount of the cured resin from the viewpoint of sufficiently improving the mechanical strength of the cured resin. If it is more than mass%, it is still more preferable, and it is most preferable if it is 60 mass% or more. From the viewpoint of improving the dispersibility of the inorganic particles in the cured resin, the content is preferably 95% by mass or less, and more preferably 90% by mass or less.

  It is preferable that the first inorganic particles having an average particle diameter in the range of 0.2 to 50 μm are contained in the entire inorganic particles in the cured resin. When such first inorganic particles are contained in the cured resin, mechanical strength such as bending strength of the cured resin is particularly high. The mechanical strength of the cured resin is particularly high when the average particle size of the first inorganic particles is 0.2 μm or more, and the high processability of the cured resin is ensured when the average particle size is 50 μm or less. Is done. In order to improve the mechanical strength of the cured resin, the average particle size of the first inorganic particles is preferably 0.3 μm or more, and more preferably 0.4 μm or more. In order to improve the processability of the cured resin, the average particle size of the first inorganic particles is preferably 30 μm or less, and particularly preferably 20 μm or less.

  It is also preferable that the second inorganic particles having an average particle diameter in the range of 0.005 to 0.1 μm are contained in the entire inorganic particles in the resin cured product. In order to improve the mechanical strength of the cured resin, the particle size of the inorganic particles is preferably larger as the first inorganic particles, but the average particle size of the second inorganic particles is 0.005 μm or more. Thus, the mechanical strength of the cured resin is also increased by the second inorganic particles. If the average particle size of the second inorganic particles is 0.005 μm or more, the aggregation of the second inorganic particles is suppressed, and there is an advantage that the second inorganic particles are easily dispersed in the matrix. Furthermore, if the average particle size of the second inorganic particles is 0.1 μm or less, the particle size of the second inorganic particles becomes smaller than the wavelength of light. The impact on is small. For this reason, when the second inorganic particles are contained in the cured resin, the mechanical strength of the cured resin is increased without impairing the transparency of the cured resin. In order to improve the mechanical strength of the cured resin, the average particle size of the second inorganic particles is preferably 0.01 μm or more, and particularly preferably 0.015 μm or more. In order to improve the transparency of the cured resin, the average particle size of the second inorganic particles is more preferably 0.08 μm or less, and particularly preferably 0.07 μm or less.

  The average particle diameter is D50 (medium particle diameter in which the cumulative volume is 50% of the total cumulative volume) measured by a laser diffraction / scattering method.

  It is preferable that both the first inorganic particles and the second inorganic particles are contained in the entire inorganic particles in the cured resin. In this case, the mechanical strength of the cured resin is improved by the first inorganic particles, the mechanical strength of the cured resin is further increased by the second inorganic particles, and the cured resin is further improved by the second inorganic particles. Increases transparency. If the first inorganic particles and the second inorganic particles are dispersed in the matrix phase, the refractive index of the matrix phase is apparently reduced due to the influence of the second inorganic particles. The difference in refractive index from the inorganic particles is considered to be small, and this is considered to contribute to further improvement in the transparency of the cured resin. Thereby, the mechanical strength and transparency of the cured resin are very high.

  Furthermore, when both the first inorganic particles and the second inorganic particles are contained in the entire inorganic particles, the gloss of the surface of the cured resin is less likely to be lost, and the cured resin is less likely to be colored. Become. This is considered to be because the frequency of the removal of the inorganic particles having a large particle size from the cured resin is reduced, and therefore the surface of the cured resin is less likely to be uneven and the surface of the cured resin is less likely to be rough. . In other words, if the surface of the cured resin is rough, dirt easily accumulates on the surface of the cured resin and coloration tends to occur, but if the surface of the cured resin is not rough, the dirt is less likely to accumulate and the gloss is further lost. It becomes hard to be broken. Furthermore, if the surface of the cured resin is rough, the surface area becomes large, and the amount of dirt attached per apparent surface area increases with respect to the amount of dirt attached per actual surface area. Although it becomes easy to occur, such a situation will be lost if the surface of the cured resin is hardly roughened.

  The ratio of the first inorganic particles and the second inorganic particles in the entire inorganic particles is not particularly limited, but the first inorganic particles may be 20% by mass to 90% by mass with respect to the entire resin cured product. More preferably, it is 40 mass% or more and 85 mass% or less. The second inorganic particles are preferably 1% by mass or more and 30% by mass or less, more preferably 2% by mass or more and 25% by mass or less, based on the entire cured resin.

  The shape of the inorganic particles is preferably spherical. In this case, the smoothness of the surface of the cured resin becomes high, and when the cured resin is fixed in the oral cavity, the oral cavity is not easily damaged by the cured resin, and the counter teeth engaged with the cured resin are worn. It becomes difficult. Furthermore, since the smoothness of the surface of the cured resin is increased, the cured resin is less likely to be colored. Further, when the cured resin is subjected to cutting with a cutting tool such as a drill bit, wear of the cutting tool is suppressed. Furthermore, when a resin cured product is formed from the curable composition as will be described later, the fluidity of the curable composition is increased, thereby increasing the moldability of the curable composition.

  The shape of the spherical inorganic particles may not be a strict sphere as long as the surface is substantially curved, but the sphericity of the inorganic particles is preferably 0.95 or more. The sphericity is more preferably 0.96 or more, and further preferably 0.97 or more. In measuring the sphericity of inorganic particles, first, microscopic images of 50 particles arbitrarily selected from the entire inorganic particles are taken. From the area of the projected cross section of each particle appearing in this microscope image and the perimeter of this cross section, the [circumferential length of a perfect circle having the same area as the area of the projected particle cross section] / [measured value of the perimeter of the projected particle section] A value is derived. The average value of the values derived for the 50 particles is the sphericity of the inorganic particles.

  The inorganic particles are preferably subjected to a surface treatment with a coupling agent. In this case, it is preferable to use a coupling agent generally used for dentistry. Examples of the coupling agent include known coupling agents such as γ-methacryloxypropyltrimethoxysilane and vinyltrimethoxysilane.

  The covering phase is composed of an acrylic polymer containing fluorine. Examples of the acrylic polymer containing fluorine include a copolymer of an appropriate acrylic polymerizable monomer not containing fluorine and an acrylic polymerizable monomer containing fluorine. Examples of the acrylic polymerizable monomer that does not contain fluorine include the same compounds as those mentioned in the description relating to the parent phase. The acrylic polymerizable monomer containing fluorine is not particularly limited, but trifluoroethyl methacrylate, perfluorooctyl ethyl methacrylate, trifluoroethyl acrylate, tetrafluoropropyl methacrylate, octafluoropentyl acrylate, octafluoropentyl methacrylate, heptadeca Examples include fluorodecyl acrylate and heptadecafluorodecyl methacrylate. Among these compounds, only one kind may be used or two or more kinds may be used in combination.

  The ratio of the fluorine-containing acrylic polymerizable monomer constituting the fluorine-containing acrylic polymer and the fluorine-containing acrylic polymerizable monomer is appropriately adjusted according to the degree of refractive index required for the coating phase. However, for example, the mass ratio of the former to the latter is in the range of 99: 1 to 70:30.

  Since the coating phase is composed of an acrylic polymer containing fluorine, the refractive index of the coating phase is smaller than the refractive index of the parent phase composed of an acrylic polymer that does not contain fluorine. The coating phase and the refractive index of the inorganic particles are sequentially reduced in this order. For this reason, when a coating phase intervenes between an inorganic particle and a parent phase, the interface between different phases with a large refractive index difference in the cured resin is reduced, thereby increasing the transparency of the cured resin.

  Furthermore, although the coating phase composed of an acrylic polymer containing fluorine is included in the cured resin, the matrix is composed of an acrylic polymer that does not contain fluorine. It becomes easy to adhere to natural teeth and metal bases. This is because an acrylic polymer that does not contain fluorine is more easily bonded to natural teeth, a metal base, or the like than an acrylic polymer that contains fluorine. For this reason, the cured resin can be firmly bonded to natural teeth, a metal base, or the like.

  The coating phase is in contact with at least some of the inorganic particles in the entire resin cured product, and at least a part of the surface of the inorganic particles in contact with the coating phase is covered with the coating phase. Thereby, the interface between different phases having a large refractive index difference in the cured resin is reduced, and the transparency of the cured resin is increased. In particular, the coating phase is preferably in contact with all inorganic particles in the cured resin. It is also preferable that the entire surface of the inorganic particles in contact with the coating phase is covered with the coating phase. In these cases, the transparency of the cured resin is particularly high.

  When the first inorganic particles and the second inorganic particles are both contained in the entire inorganic particles, the first inorganic particles having a larger average particle size have a greater influence on the transparency of the cured resin. Effect. For this reason, it is preferable that the coating phase intervenes between the first inorganic particles and the parent phase. In this case, the first inorganic particles increase the mechanical strength of the cured resin and increase the transparency of the cured resin. The coating phase is in contact with at least some of the first inorganic particles as a whole, and at least a part of the surface of the first inorganic particles in contact with the coating phase is covered with the coating phase. ing. Thereby, the interface between different phases having a large refractive index difference in the cured resin is reduced, and the transparency of the cured resin is increased. In particular, it is preferable that the coating phase is in contact with all the first inorganic particles. It is also preferred that the entire surface of the first inorganic particles in contact with the coating phase is entirely covered with the coating phase. A coating phase may or may not be interposed between the second inorganic particles and the parent phase. Even if the coating phase is not interposed between the second inorganic particles and the matrix phase, the transparency of the resin cured product is improved by the second inorganic particles as described above.

  The content of the coating phase in the cured resin is not particularly limited, but from the viewpoint of sufficiently reducing the interface between the different phases having a large refractive index difference in the cured resin, it is 1% by mass or more based on the entire cured resin. Preferably, it is more preferably 5% by mass or more. In addition, this content is 20% by mass or less from the viewpoint of securing high adhesiveness of the cured resin and suppressing the amount of fluorine-containing acrylic polymer to achieve cost reduction. Preferably, it is more preferably 10% by mass or less.

  An example of a method for producing a cured resin will be described.

  First, an intermediate composition containing an acrylic polymerizable monomer containing fluorine, an acrylic polymerizable monomer containing no fluorine, and inorganic particles is prepared.

  The acrylic polymerizable monomer containing fluorine and the acrylic polymerizable monomer not containing fluorine in the intermediate composition are raw materials of the coating phase, and the ratio of both is the acrylic polymerizable monomer containing fluorine constituting the coating phase; It adjusts so that it may correspond with the ratio with the acrylic polymerizable monomer which does not contain a fluorine.

  The ratio of the inorganic particles in the intermediate composition is determined according to the ratio between the coating phase and the inorganic particles in the resin cured product. When the entire inorganic particles in the cured resin contain the first inorganic particles and the second inorganic particles, the intermediate composition contains only the first inorganic particles out of the entire inorganic particles, and the second inorganic particles It does not have to contain particles. The inorganic particles to be blended in the intermediate composition are preferably subjected to a surface treatment with a coupling agent in advance.

  The intermediate composition preferably contains a polymerization initiator. Examples of the polymerization initiator include known polymerization initiators such as a heat polymerization initiator and a photopolymerization initiator that are generally used for dental use. Specific examples of the polymerization initiator include heat polymerization initiators such as benzoyl peroxide, tertiary butyl peroxide and methyl ethyl ketone peroxide, and photopolymerization initiators such as camphorquinone, benzoin and benzophenone. Among these compounds, only one kind may be used or two or more kinds may be used in combination.

  An intermediate composition is prepared by mixing the above components.

  An intermediate cured product is formed by curing the intermediate composition after it is formed into an appropriate shape. The intermediate composition is cured by an appropriate method according to its curing characteristics. For example, when the intermediate composition contains a thermal polymerization initiator, the intermediate composition is cured by heating, and when the intermediate composition contains a photopolymerization initiator, the intermediate composition has energy such as ultraviolet rays. It is cured by irradiating the line. This intermediate cured product has a structure in which inorganic particles are dispersed in an acrylic polymer containing fluorine. The fluorine-containing acrylic polymer is formed by copolymerization of the fluorine-containing acrylic polymerizable monomer and the fluorine-free acrylic polymerizable monomer in the intermediate composition.

  The intermediate cured product is pulverized to obtain composite particles. The composite particles include inorganic particles and a coating made of an acrylic polymer. The coating is in contact with at least some of the inorganic particles in the entire composite particle, and at least a part of the surface of the inorganic particles with which the coating is in contact is covered with the coating. In particular, the coating is preferably in contact with all the inorganic particles in the entire composite particle. Moreover, it is preferable that the entire surface of the inorganic particles in contact with the coating is covered with the coating. The entire composite particle may contain a coating that is not in contact with the inorganic particles. A plurality of inorganic particles may be in contact with one coating. The particle size of the composite particles is not particularly limited, but the maximum particle size of the composite particles is preferably 250 μm or less. That is, it is preferable that the composite particles have a particle size that passes through a sieve having an opening of 250 μm or less. In this case, the dispersibility of the inorganic particles and the coating phase in the cured resin becomes very good.

  Subsequently, a curable composition containing an acrylic polymerizable monomer not containing fluorine and composite particles is prepared.

  The acrylic polymerizable monomer which does not contain fluorine in the curable composition is a raw material for the mother phase. The ratio of the fluorine-containing acrylic polymerizable monomer and the composite particles in the curable composition is determined according to the ratio of the matrix, the coating phase, and the inorganic particles in the resin cured product.

  In the curable composition, inorganic particles different from the inorganic particles in the composite particles may be blended. In the case where the entire inorganic particles in the resin cured product include the first inorganic particles and the second inorganic particles, when the intermediate composition contains only the first inorganic particles among the entire inorganic particles, the curable composition Second inorganic particles are blended into the product. It is preferable that the inorganic particles to be blended with the molding material have been subjected to surface treatment with a coupling agent in advance.

  As in the case of the intermediate composition, the curable composition preferably contains a polymerization initiator. Further, the curable composition may be a solvent, a polymerization inhibitor, an antioxidant, an ultraviolet absorber, a light stabilizer, an antibacterial agent, a fluorine sustained-release agent, a color pigment, and other conventionally known additives as necessary. It may contain. In particular, as an additive contained in a curable composition for dental use, an appropriate compound generally used for dental care is used.

  A curable composition is prepared by mixing the above components. The content of the entire inorganic particles of the curable composition is not particularly limited, but is 20% by mass or more based on the total solid content in the curable composition from the viewpoint of sufficiently improving the mechanical strength of the resin cured product. More preferably, it is more preferably 40% by mass or more, and most preferably 60% by mass or more. This content is preferably 95% by mass or less from the viewpoint of improving the dispersibility of the inorganic particles in the cured resin. The content of the coating phase in the curable composition is not particularly limited, but from the viewpoint of sufficiently reducing the interface between different phases having a large refractive index difference in the cured resin, it is 1% by mass or more based on the entire cured resin. Preferably, it is more preferably 5% by mass or more. In addition, this content is 20% by mass or less from the viewpoint of securing high adhesiveness of the cured resin and suppressing the amount of fluorine-containing acrylic polymer to achieve cost reduction. Preferably, it is more preferably 10% by mass or less. The solid content in the curable composition is a component (nonvolatile content) excluding substances that are removed from the curable composition or the resin cured product by volatilization in the process of forming the resin cured product from the curable composition. That is.

  A cured resin is formed by curing the curable composition after it is formed into an appropriate shape. The curable composition is cured by an appropriate method according to its curing characteristics. For example, when the curable composition contains a thermal polymerization initiator, the curable composition is cured by heating, and when the curable composition contains a photopolymerization initiator, the curable composition is It is cured by irradiation with energy rays such as ultraviolet rays. In the process of curing the curable composition, an acrylic polymerizable monomer containing no fluorine in the curable composition is polymerized to form a matrix composed of an acrylic polymer containing no fluorine. . The composite particles are dispersed in the matrix phase, and the coating on the composite particles becomes the coating phase, and the coating phase is chemically bonded to the matrix phase. Thereby, a resin cured product is obtained.

  As described above, the cured resin has high durability because of its high mechanical strength, and also has high aesthetics because of its high transparency. For this reason, the resin cured product is preferably used as a dental material. This resin cured product is suitable for cutting.

  The curable composition is particularly suitable as a dental material. In this case, the curable composition is formed into an appropriate shape such as a prismatic shape, a columnar shape, a square plate shape, a disc shape, or a prosthetic shape such as a denture, an inlay, or a crown. Resin cured products having shapes such as prismatic, cylindrical, square plate, and disk are cut by a CAD / CAM device to produce dental prostheses such as dentures, inlays, and crowns. Is done. When the cured resin is cut by a CAD / CAM device, a uniform dental prosthesis can be obtained as compared with the case of manual work. In addition, when a problem such as partial missing of the dental prosthesis fixed in the oral cavity occurs, it becomes easy to repair and regenerate the dental prosthesis based on the CAD data. In addition, if a dental prosthesis fixed in the oral cavity is chipped, if it is very small, the chip is filled with a dental resin material such as a paste-like resin that is commonly used for dental treatment. Can be easily repaired. In this case, since both the dental prosthesis and the dental resin material are resin materials, the adhesion between them is good.

  Hereinafter, a method for forming a cured resin, particularly when the curable composition is a dental material, will be described.

  The curable composition is polymerized and cured by irradiating or heating light corresponding to the composition, or by irradiating and heating the light. Thereby, a dental material is obtained.

  For example, when the curable composition contains a heat polymerization type initiator, a mold and a lid are prepared. The mold has a cavity. The shape of the cavity is, for example, a prismatic shape, a cylindrical shape, a square plate shape, a disc shape, or a dental prosthesis shape such as a denture, an inlay, or a crown. After the cavity of the mold is filled with the curable composition, the inside of the cavity is decompressed to remove bubbles from the curable composition. Next, the curable composition is polymerized and cured by heating under pressure or normal pressure in a state where the lid is attached to the mold and the cavity is closed. Thereby, a dental material is obtained. The applied pressure and heating temperature at the time of polymerization and curing may be changed with time as necessary.

  When the curable composition contains a photopolymerization type initiator, for example, first, a mold having a portion that can transmit light and a lid are prepared. The mold has a cavity. The shape of the cavity is, for example, a prismatic shape, a cylindrical shape, a square plate shape, a disc shape, or a dental prosthesis shape such as a denture, an inlay, or a crown. After the mold cavity is filled with the curable composition, the inside of the cavity is decompressed to remove bubbles from the curable composition. Next, in a state where the lid is attached to the mold and the cavity is closed, the curable composition is irradiated with light under pressure or normal pressure. Thereby, the curable composition is polymerized and cured, and a dental material is obtained. At the time of polymerization curing, the curable composition after light irradiation may be subjected to a heat treatment as a post-curing treatment as necessary.

  The material of the mold and the lid having a portion that can transmit light is not particularly limited, and examples thereof include stainless steel, Teflon (registered trademark), silicone, glass, PET, and polycarbonate. It is preferable to perform a treatment such as attaching a release agent to the surfaces of the mold and the lid.

  The curable composition is suitable for forming a dental material as described above, but can also be applied to electronic material applications such as a sealing material, an adhesive, and a laminate forming material.

[Production of composite particles]
In Examples 1 to 13 and Comparative Examples 2 and 3, the components shown in the “Composition” column of “Composite Particles” in Tables 1 to 3 below were blended and further mixed by stirring to obtain an intermediate composition. It was. An intermediate cured product was obtained by curing the intermediate composition by heating. The intermediate cured product was pulverized and further sieved with a sieve having openings shown in Tables 1 to 3 to obtain composite particles.

[Preparation of curable resin and production of cured resin]
In Examples 1-13 and Comparative Examples 1-4, the component shown by the column of "the composition of a curable composition" of the following Tables 1-3 is mix | blended, and also a curable composition is obtained by stirring and mixing. It was.

  In Examples 1, 2, 4 to 13 and Comparative Examples 1 to 4, the curable composition was made of a stainless steel mold (cavity size 50 mm × 40 mm × 5 mm, 50 mm × 40 mm × 2 mm and 50 mm × 40 mm × 1 mm 3 The curable composition in the cavity was degassed under reduced pressure, and a stainless steel lid was attached to the mold. In this state, the curable composition was heated at 80 ° C. for 1 hour and then heated at 120 ° C. for 1 hour to cure the curable composition. Thereby, a resin cured product was obtained.

In Example 3, a molding die (three types of cavity size 50 mm × 40 mm × 5 mm, 50 mm × 40 mm × 2 mm and 50 mm × 40 mm × 1 mm) made from a glass plate and a stainless steel frame was filled with a curable resin, After the curable composition in the cavity was degassed under reduced pressure, a glass lid was attached to the mold. In this state, ultraviolet light having a wavelength of 365 nm and an intensity of 100 mW / cm ² is irradiated from the dental medical photopolymerization device to the curable resin through the glass surface on one side of the mold for 5 minutes, and then under the same conditions. Ultraviolet light was irradiated for 5 minutes toward the curable resin through the glass surface on the opposite side of the mold. Thereby, the curable composition was cured to obtain a cured resin.

[Evaluation test]
The following evaluation tests were performed on the cured resin obtained in Examples and Comparative Examples. The results are shown in Tables 1-3.

(Measurement of refractive index)
Mother phase: A composition having a composition obtained by removing inorganic particles and composite particles from the curable composition was prepared, and the composition was cured to obtain a cured product. The refractive index of this cured product was determined by Method A (measurement method using an Abbe refractometer) in JIS K7142 “Method for measuring refractive index of plastic”.

  Coating phase: A composition having a composition obtained by removing inorganic particles from the intermediate composition was prepared, and this composition was cured to obtain a cured product. The refractive index of this cured product was determined by Method A (measurement method using an Abbe refractometer) in JIS K7142 “Method for measuring refractive index of plastic”.

  Inorganic particles: The refractive index of the inorganic particles was determined by the method B (immersion method using a microscope (Becke's line method)) in JIS K7142 “Method for measuring refractive index of plastics”.

(Adhesion evaluation test)
A test piece having a size of 10 mm × 10 mm × 5 mm was cut out from the cured resin, and the surface of the test piece was polished with # 600 water-resistant abrasive paper. An adhesive (curable composition in Example 2) was applied to a 3 mm diameter region (adhesion surface) on the tip surface of a circular stainless steel rod (SUS304, diameter 6 mm, length 20 mm). The test piece was pressed. In this state, the adhesive was heated at 80 ° C. for 1 hour, and then heated at 120 ° C. for 1 hour, thereby bonding the test piece to the stainless steel bar.

  By carrying out a tensile test with a tensile tester on the stainless steel bar to which this test piece is bonded, under the condition of a crosshead speed of 1 mm / min, the breaking strength between the test piece and the stainless bar on the bonded surface can be increased. It was measured. This test was performed 5 times, and the average value of the obtained breaking strength values was used as an index of adhesion.

(Bending strength test (normal))
A test piece having a size of 25 mm × 2 mm × 2 mm was cut out from the cured resin. The strength at break of the test piece was measured using a bending tester under the condition of a crosshead speed of 1 mm / min. The same test was performed on five test pieces, and the average value of the strength at break obtained was used as an index of bending strength. This value is a representative value of the strength of the cured resin.

(Bending strength test (after water immersion))
A test piece having a size of 25 mm × 2 mm × 2 mm was cut out from the cured resin. This test piece was first immersed in water at 37 ° C. for 24 hours. Next, the strength at break of this test piece was measured using a bending tester under the condition of a crosshead speed of 1 mm / min. The same test was performed on five test pieces, and the average value of the strength at break obtained was used as an index of bending strength. This value is a representative value of the durability of the cured product.

(Transparency test)
A test piece having a size of 13 mm × 13 mm × 1 mm was cut out from the cured resin. This test piece was buffed until the thickness became 0.8 mm. The total light transmittance of this test piece was measured with a haze meter. The total light transmittance of the air layer was 100%. The same test was performed on three test pieces, and the average value of the obtained values was used as an index of transparency. This value is a representative value of the aesthetics of the cured product.

The details of the components shown in Tables 1 to 3 are as follows.
* 1: Spherical fused silica, average particle size 0.6 μm, sphericity 0.98.
* 2: Spherical fused silica, average particle size 1.5 μm, sphericity 0.98.
* 3: Spherical fused silica, average particle size 0.3 μm, sphericity 0.98.
* 4: Spherical fused silica, average particle size 48 μm, sphericity 0.96.
* 5: Spherical fused silica, average particle size 0.050 μm, sphericity 0.99.
* 6: Spherical fused silica, average particle size 0.015 μm, sphericity 0.99.
* 7: Spherical fused silica, average particle size 0.007 μm, sphericity 0.99.
* 8: Spherical fused silica, average particle size 0.080 μm, sphericity 0.99.
* 9: γ-methacryloxypropyltrimethoxysilane.
* 10: Triethylene glycol dimethacrylate.
* 11: Di (phenylglycidyl ether acrylate) -hexamethylene diurethane.
* 12: trifluoroethyl methacrylate.
* 13: Perfluorooctyl ethyl methacrylate.
* 14: Benzoyl peroxide.
* 15: Trimethylolpropane trimethacrylate.

  The average particle size of the inorganic particles was determined by measuring the D50 of the inorganic particles obtained by measuring with a laser diffraction / scattering method using model number LA-920 manufactured by Horiba Ltd. (the cumulative volume is 50% of the total cumulative volume). Medium particle size). In the measurement, inorganic particles were dispersed in the ion-exchanged water while applying ultrasonic waves to the ion-exchanged water, and the average particle diameter was measured in a state where the transmittance of the resulting dispersion was 80 to 90%. In the measurement, the relative refractive index was not used.

  In measuring the sphericity of the inorganic particles, first, the inorganic particles were observed with a real surface view microscope (model number VF-7800) manufactured by Keyence Corporation. From the image obtained by this, about 50 arbitrary particles, The area of the particle projection cross section (the apparent area appearing in the image) and the perimeter of this particle projection cross section (the apparent perimeter appearing in the image) were measured. Next, the value of [circumferential length of a perfect circle having the same area as that of the particle projected cross section] / [measured value of the peripheral length of the particle projected cross section] was derived for each of 50 particles, and the average of the obtained values. The value was defined as sphericity.

Claims (8)

  A matrix comprising an acrylic polymer containing no fluorine, a coating phase consisting of an acrylic polymer containing fluorine, and inorganic particles, and the coating phase and the inorganic in the matrix A cured resin, in which particles are dispersed, and the coating phase is interposed between at least a part of the whole inorganic particles and the matrix phase.   The first inorganic particles having an average particle diameter in the range of 0.2 to 50 μm and the second inorganic particles having an average particle diameter in the range of 0.005 to 0.1 μm are included in the entire inorganic particles. The cured resin product according to claim 1.   The cured resin product according to claim 1, wherein the inorganic particles are spherical.   The cured resin product according to any one of claims 1 to 3, which is a dental material.   An acrylic polymerizable monomer containing no fluorine and composite particles, wherein the composite particles include inorganic particles and a coating covering the surfaces of the inorganic particles, and the coating includes an acrylic heavy polymer containing fluorine. A curable composition composed of a coalescence. A step of preparing an intermediate composition containing an acrylic polymerizable monomer containing fluorine, an acrylic polymerizable monomer not containing fluorine, and inorganic particles;
A step of curing the intermediate composition and pulverizing the intermediate cured product thereby to produce composite particles;
A method for producing a cured resin comprising a step of preparing a curable composition containing an acrylic polymerizable monomer containing no fluorine and the composite particles, and a step of curing the curable composition. A step of preparing an intermediate composition containing an acrylic polymerizable monomer containing fluorine, an acrylic polymerizable monomer containing no fluorine, and first inorganic particles having an average particle size in the range of 0.2 to 50 μm. ,
A step of curing the intermediate composition and pulverizing the intermediate cured product thereby to produce composite particles;
Preparing a curable composition containing a fluorine-free acrylic polymerizable monomer, the composite particles, and second inorganic particles having an average particle diameter in the range of 0.005 to 0.1 μm; and A method for producing a cured resin comprising a step of curing the curable composition.   The method for producing a cured resin product according to claim 6 or 7, wherein the maximum particle size of the composite particles is 250 µm or less.