JP2018062490A - Dental resin composite material and production method thereof - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide dental resin composite materials in which air bubbles, the change of color/uneven coloring, and the like are hardly generated, and which contain a thermoplastic resin having a high melting point or fluidization temperature and a metal oxide subjected to surface treatment with a coupling agent, and to provide production methods of the dental composite materials.SOLUTION: A dental resin composite material contains a thermoplastic resin whose melting point or fluidization temperature is 300°C or more, and a metal oxide subjected to a surface treatment with a coupling agent, the metal oxide subjected to a surface treatment having a weight-loss rate of 0.5% or less from 120°C to 800°C when a thermogravimetric analysis is conducted at heating-rate of 10°C/minute under an air atmosphere.SELECTED DRAWING: None

Description

  The present invention relates to a dental resin composite material and a method for producing the same.

  Thermoplastic resins have mechanical and electrical characteristics, light weight and excellent workability, and are important materials that can be used in a wide range of fields, from electrical components, building materials, agricultural materials, and household goods. It has become. Although there are many examples of using the resin alone for the above applications, fillers are widely used to improve the mechanical properties, particularly performance such as strength and heat resistance.

  These resin materials are spreading to applications as substitute materials for various metal parts by taking advantage of their characteristics such as contribution to weight reduction while maintaining strength, excellent chemical resistance, and high productivity. The amount of use continues to increase, and in recent years, in particular, it has been actively used in the medical material field.

  However, in general, resin materials have lower heat-resistant temperatures and mechanical strength than metal materials, and it is not easy to simply replace all previous applications with resin parts. In order to solve the above-mentioned problems, resins with high heat resistance and strength such as engineering plastics and super engineering plastics have been developed, and composites that contain inorganic particles as fillers to further improve the function depending on the purpose. Technology has also been proposed (Patent Document 1).

  For example, techniques for adding fillers to super engineering plastics and using them as dental materials have been proposed (Patent Documents 2 to 5).

  As the filler, metal oxides such as silica, titania, alumina and zirconia are widely used. When using metal oxide as a filler, surface treatment is performed with a coupling agent such as a silane coupling agent, thereby improving the dispersibility of the filler in the resin and improving the physical properties such as mechanical strength. Often it is possible.

  The coupling agent usually has a functional group that reacts and interacts with an inorganic compound such as a metal oxide and a functional group that reacts and interacts with an organic compound such as a resin. Here, the functional group that reacts and interacts with the organic compound is usually an organic functional group. When a metal oxide surface-treated with a coupling agent having an organic functional group is compounded with a thermoplastic resin, a melt-kneading is performed to melt the thermoplastic resin by applying heat that is normally performed. Some or all of the organic functional groups of the agent may decompose, or the coupling agent remaining on the surface as a reaction residue may volatilize. In particular, when a resin having a high melting point or fluidization temperature such as super engineering plastic is used, the influence is remarkable.

  Examples of dental materials in which a resin having a high melting point or fluidization temperature of 300 ° C. or higher and a metal oxide surface-treated with a coupling agent as a filler are combined include the aforementioned Patent Documents 2 to 5. .

  In Patent Document 2, alumina fiber (or zirconia fiber) is surface-treated with a weight ratio of silane (coupling agent) to ceramic of approximately 1: 100, and is blended with polyether ether ketone resin or polyether ketone ketone resin. Dental materials are described. The influence of the amount of the surface treatment agent on the filler surface treatment, the amount of the surface treatment agent on the filler surface after the surface treatment and the influence thereof are not specifically shown.

  Patent Document 3 proposes a technique for using an organic-inorganic composite, in which an inorganic particle mixture is blended in a thermoplastic resin containing at least one selected from polyaryl ether ketone resins and polysulfone resins as a main component, as a dental material. It is described that the inorganic particles are preferably surface-treated with a silane coupling agent or the like, and the coupling agent is preferably in the range of 1 to 10 parts by mass per 100 parts by mass of the inorganic particles.

  In Patent Document 4, there is a technique of using, as a dental material, a resin composite material composed of a thermoplastic resin having a melting point or fluidization temperature in a range of 200 ° C. to 500 ° C. and inorganic particles surface-treated with a surface treatment agent. Proposed. In the surface treatment of inorganic particles, the amount of the surface treatment agent is calculated by dividing the product of the weight of the inorganic particles and the specific surface area of the inorganic particles by the minimum surface area of the surface treatment agent. It is described that it is preferable to be in the range of 0.7 to 1.2 with respect to (theoretical value). Specifically, a resin composite material is described that uses inorganic particles that have been surface-treated under a condition of 1.0 with respect to the optimum surface treatment agent amount (theoretical value).

  Patent Document 5 proposes a dental resin composite material including a polyaryl ether ketone resin and amorphous silica particles. It is described that the amount of the surface treatment agent used when the amorphous silica particles are surface-treated is preferably 1 to 10 parts by mass per 100 parts by mass of the amorphous silica particles. Specifically, an example is described in which surface treatment is performed with 2.4 parts by mass of a surface treatment agent per 100 parts by mass of amorphous silica.

  In any of the documents, the weight loss rate in the optimum thermogravimetric analysis of the inorganic particles used for the composite material is not described.

JP 2005-330378 A Special table 2008-541874 gazette JP 2013-144778 A JP 2013-144783 A JP 2014-152150 A

  As described above, a composite material containing a thermoplastic resin having a high melting point or fluidization temperature such as a polyaryl ether ketone resin and a filler (particularly a metal oxide) surface-treated with a coupling agent for dental use. Use is proposed. By treating the surface of the metal oxide used as the filler with a coupling agent, the affinity between the resin and the metal oxide can be improved, and it is easy to improve the color tone and improve the strength. It becomes.

  The composite of the thermoplastic resin and the metal oxide is usually performed by plasticizing the thermoplastic resin with heat. When a thermoplastic resin having a high melting point or fluidization temperature as described above is used, since the plasticization temperature is high, a high temperature is usually required at the time of compounding.

  A composite material comprising a thermoplastic resin having a high melting point or fluidization temperature as described above (particularly a thermoplastic resin having a melting point or fluidization temperature of 300 ° C. or higher) and a metal oxide surface-treated with a coupling agent. When it is used to mold into a dental member, discoloration / color unevenness may occur in addition to poor appearance and reduced strength due to the generation of bubbles in the dental member.

  The present invention has been made to solve the above-mentioned problems, and is a metal oxide surface-treated with a thermoplastic resin having a high melting point or fluidization temperature and a coupling agent, which is less likely to cause bubbles and discoloration / color unevenness. And a method for producing the dental composite material.

  In order to solve the above problems, the inventors have conducted intensive studies, and as a result, have a melting point or a fluidization temperature of 300 ° C. or higher, and a dental resin that includes a metal oxide surface-treated with a coupling agent. The weight loss rate from 120 ° C. to 800 ° C. in a thermogravimetric analysis of a metal oxide, which is a composite material and surface-treated with a coupling agent, is 10 ° C./min in an air atmosphere is 0.1. The present inventors have found that the above problem can be solved by being 5% or less, and have reached the present invention.

  That is, the present invention relates to a composite material comprising a thermoplastic resin having a melting point or fluidization temperature of 300 ° C. or higher and a metal oxide surface-treated with a coupling agent, wherein the surface-treated metal oxide is It is a surface-treated metal oxide having a weight reduction rate from 120 ° C. to 800 ° C. of 0.5% or less by thermogravimetric analysis performed at a heating rate of 10 ° C./min in an atmosphere. It is a dental resin composite material.

  The average volume particle size of the metal oxide is preferably in the range of 0.1 μm to 3 μm, and the content of the metal oxide is preferably in the range of 20 to 60% by mass of the dental resin composite material.

  In addition, the dental resin composite material of the present invention is subjected to a surface treatment using a metal oxide as a coupling agent under the conditions satisfying the following formula (1), and the surface-treated metal oxide has a melting point or fluidization temperature. It can manufacture by knead | mixing the composition containing a 300 degreeC or more thermoplastic resin on 350-450 degreeC conditions.

X [g] = (A / B) × C (1)
(Wherein, X is the amount of coupling agent added per gram of metal oxide, A is the specific surface area of the metal oxide [m ² / g], B is the minimum coating area of the coupling agent [m ² / g], The coefficient C is 0.05 to 0.6)

  A dental prosthesis can be produced by hot press molding the dental composite material. In addition, a dental treatment material having a thickness of 10 mm or more can be produced by injection molding or extrusion molding of the dental composite material.

  ADVANTAGE OF THE INVENTION According to this invention, the dental resin composite material which can produce the dental member by which the bubble and discoloration / color nonuniformity were suppressed can be provided. Further, in the dental prosthesis and the dental treatment material manufactured using the dental resin composite material, bubbles and discoloration / color unevenness are suppressed.

  Thermogravimetric analysis performed at a heating rate of 10 ° C./min in an air atmosphere for a composite material containing a thermoplastic resin having a melting point or fluidization temperature of 300 ° C. or higher and a metal oxide surface-treated with a coupling agent A dental member in which bubbles and discoloration / color unevenness are suppressed by using a metal oxide surface-treated with a coupling agent having a weight reduction rate from 120 ° C. to 800 ° C. of 0.5% or less. A dental resin composite material that can be produced can be obtained.

  The cause of this is not necessarily clear, but the present inventors speculate as follows.

  When a metal oxide surface-treated with a coupling agent is compounded with a thermoplastic resin having a melting point or fluidization temperature of 300 ° C. or higher to produce a resin composite material, the thermoplastic resin is usually treated with the melting point or fluidity. It is carried out by plasticizing at a temperature equal to or higher than the crystallization temperature (hereinafter also referred to as the melting temperature) and melt-kneading. At that time, in consideration of handleability, a granular (pellet-shaped) resin composite material is usually obtained. Then, as a method for producing a dental member from the resin composite material thus composited, a method of plasticizing the resin composite material again at a melting temperature and pouring or pushing into a mold having a desired shape, resin The main method is, for example, a method in which a composite material is formed into a block shape and then cut into a desired shape. When the resin composite material is manufactured, if it is directly formed into a block shape, the block-shaped resin composite material can be cut into a desired shape. Generally, a suitable melting temperature for melt kneading is selected from a range of a melting point or fluidization temperature to a temperature 100 ° C. higher than the melting point or fluidization temperature.

  Here, since the coupling agent usually has a low molecular weight and an organic functional group, when a thermoplastic resin having a high melting point or fluidization temperature and a metal oxide surface-treated with the coupling agent are melt-kneaded, metal oxidation is performed. Coupling agent reaction residue on the surface of the object or one part (mainly organic functional group) of the coupling agent bonded to the surface of the metal oxide may partially vaporize or decompose to generate gas. . As a result, the above-mentioned gas may be contained in the pellets of the resin composite material obtained by melt-kneading and may exist as bubbles.

  When plastic material pellets having such bubbles are plasticized and poured into a mold or pressed into a dental member to form the dental member, it is difficult to remove the bubbles, Air bubbles are likely to be generated. In addition, even when the bubbles can be removed, the part where the bubbles existed is longer in contact with a highly reactive gas such as oxygen at a higher temperature than the other parts, so the discoloration It tends to occur, and overall discoloration and uneven color are likely to occur. This is because, even in the method of molding a resin composite material into a large lump such as a block shape and then cutting it into a desired shape, the technique for molding into a large lump is made by plasticizing the pellets of the resin composite material into a mold The same problem occurs with the pouring and pushing technique

  Here, by using a metal oxide whose weight reduction rate from 120 ° C. to 800 ° C. is 0.5% or less in a thermogravimetric analysis performed at a heating rate of 10 ° C./min in an air atmosphere, Gas components generated during kneading can be reduced, and bubbles in the pellet can be easily suppressed. As a result, the dental resin composite material is plasticized and poured into a mold or pushed into it, so that when a dental member is molded into a desired shape, the occurrence of bubbles and discoloration / color unevenness is suppressed, and dental It becomes easy to finish in a preferable state as a working member.

  In addition, when the block is shaped into a large lump such as a block shape and then cut into a desired shape as a dental member, if the large lump is molded using a screw such as injection molding or extrusion molding, the screw is sufficiently stirred. By doing so, it is possible to suppress the generation of bubbles in the molded body due to the bubbles remaining in the pellets as a material to some extent. However, even when plasticizing with a screw, if there are a large amount of bubbles, it may be difficult to remove sufficiently, and the part where the bubbles were present is compared with other parts As a result, the time spent in contact with a highly reactive gas such as oxygen becomes longer, so discoloration is likely to occur, which may cause overall discoloration and uneven color.

  Here, by using a metal oxide whose weight reduction rate from 120 ° C. to 800 ° C. is 0.5% or less in a thermogravimetric analysis performed at a heating rate of 10 ° C./min in an air atmosphere, Gas components generated during kneading can be reduced, and bubbles in the pellet can be easily suppressed. As a result, when a dental resin composite material is molded into a desired shape as a dental member by injection molding or extrusion molding, the occurrence of bubbles and discoloration / color unevenness in the dental member is suppressed. It becomes easy to finish in a more preferable state as a member.

  There are also cases where dental members are molded by plasticizing a mass (ingot) of a certain size and then pouring into or pushing into a mold, but similar problems occur when the ingot contains bubbles. To do. When producing an ingot from a pellet, it becomes easy to suppress the bubble in an ingot by producing from the pellet which suppressed the bubble as mentioned above.

<A thermoplastic resin having a melting point or fluidization temperature of 300° C. or higher>
As the thermoplastic resin having a melting point or fluidization temperature of 300 ° C. or higher used for the dental resin composite material of the present invention, a known thermoplastic resin can be used without any particular limitation. In the case of a resin having a high melting point or fluidization temperature of 300 ° C. or higher, as described above, a high melting temperature of 300 ° C. or higher (melting point or fluidization temperature or higher) is usually used when melt-kneading a composite with a metal oxide. Therefore, in the metal oxide surface-treated with the coupling agent, volatilization and decomposition of the coupling agent reaction residue on the surface and one part of the coupling agent bonded to the surface of the metal oxide may occur. It tends to occur. In the metal oxide surface-treated with a coupling agent, the volatilization and decomposition of the coupling agent reaction residue on the surface and a part of the coupling agent bonded to the surface of the metal oxide are those with higher temperatures during melt kneading. Therefore, the higher the melting point or fluidization temperature of the thermoplastic resin, the greater the effect of the present invention, which is preferable. Therefore, the melting point or fluidization temperature of the thermoplastic resin is preferably 320 ° C. or higher, more preferably 340 ° C. or higher. The melting point or fluidization temperature of the thermoplastic resin may be 500 ° C. or less, preferably 430 ° C. or less, and more preferably 400 ° C. or less, from the viewpoint of material selection and availability.

  Examples of such thermoplastic resins include polyphenylsulfone (PES, PESU: fluidization temperature around 360 ° C., suitable melting temperature 360-390 ° C.), polyamideimide (PAI: melting point 300 ° C., suitable melting temperature). 320 to 370 ° C), polyetherimide (PEI: fluidization temperature around 340 ° C, suitable melting temperature 340 to 430 ° C), liquid crystal polymer (LCP: fluidization temperature around 320 ° C, suitable melting temperature 320 to 400 ° C) Polyaryl ether ketone (PAEK: melting point 340 to 390 ° C., suitable melting temperature 340 to 400 ° C.).

  Among these thermoplastic resins having a melting point or fluidization temperature of 300 ° C. or higher, a polyaryl ether ketone resin is particularly preferable. The polyaryletherketone resin is mentioned as a preferred thermoplastic resin from the viewpoint of having favorable physical properties for use in dental applications such as high strength and good moldability.

  The polyaryl ether ketone resin is a thermoplastic resin containing at least an aromatic group, an ether group (ether bond) and a ketone group (ketone bond) as its structural unit. In many cases, a phenylene group has an ether group and a ketone group. It has a linear polymer structure bonded through each other. Typical examples of the polyaryl ether ketone resin include polyether ketone (PEK, melting point 370 ° C.), polyether ether ketone (PEEK, melting point 340 ° C.), polyether ketone ketone (PEKK, melting point 360 ° C.) as described above. And polyether ketone ether ketone ketone (PEKEKK, melting point 390 ° C.). The aromatic group constituting the structural unit of the polyaryl ether ketone resin may have a structure having two or more benzene rings such as a biphenyl structure. In addition, the structural unit of the polyaryl ether ketone resin may contain a sulfonyl group or another monomer unit that can be copolymerized.

  Among these polyaryl ether ketone resins, from the viewpoint of color tone and physical properties, a polyether ether ketone having a repeating unit in which an ether group and a ketone group constituting a main chain are arranged in the order of ether, ether, and ketone, It is preferable to use a polyether ketone ketone having repeating units arranged in the order of ether, ketone and ketone.

<Metal oxide surface-treated with a coupling agent>
The dental resin composite material of the present invention contains a metal oxide surface-treated with a coupling agent. By performing the surface treatment with the coupling agent, the affinity between the resin and the metal oxide can be improved, and it becomes easy to improve the color tone and the strength. The metal oxide surface-treated with the coupling agent used in the present invention has a weight reduction rate of 0 to 120 ° C. in a thermogravimetric analysis performed at a temperature rising rate of 10 ° C./min in an air atmosphere. .5% or less. Dental component in which bubbles and discoloration / color unevenness are suppressed by using a metal oxide surface-treated with a coupling agent having a weight loss rate of 120% to 800 ° C. in thermogravimetric analysis of 0.5% or less Can be easily produced.

  Examples of the metal oxide include silica, titania, zirconia, and alumina, or composite inorganic oxides such as silica-zirconia, silica-titania, and silica-alumina, or group 1 metal oxides to these composite inorganic oxides. Examples include added oxides. Among these, silica-based metals selected from metal composite oxides mainly composed of silica, such as silica or silica-zirconia, silica-titania, silica-alumina, etc., particularly because good color tone can be easily obtained as a dental material. Oxides are preferred, and silica is most preferred. Here, having silica as the main component means that the metal oxide contains 50 mass% or more of the silica component, and preferably 80 mass% or more.

  Further, the metal oxide before the surface treatment with the coupling agent is preferably one having high thermal stability, and is 120 ° C. by thermogravimetric analysis performed at a temperature rising rate of 10 ° C./min in an air atmosphere. Is preferably 0.1% or less, more preferably 0.05% or less.

  The shape / internal structure of the metal oxide is not particularly limited and may have any shape and internal structure. Preferred shapes include spherical shapes, indefinite shapes, whisker shapes, and the like. Is a solid structure.

The specific surface area of the metal oxide is not particularly limited. As will be described later, a metal oxide surface-treated with a coupling agent having a thermal weight reduction rate of 0.5% or less after surface treatment is used as a composite material. In this case, the specific surface area of the metal oxide is preferably 3 m ² / g or more, and more preferably 10 m ² / g or more, from the viewpoint that the effect of the present invention is easily obtained. The specific surface area is preferably 50 m ² / g or less, more preferably 25 g / m ² or less. In the present invention, the specific surface area of the metal oxide is measured by a nitrogen adsorption BET method.

  The particle size of the metal oxide is not particularly limited. As will be described later, a metal oxide surface-treated with a coupling agent having a thermal weight reduction rate of 0.5% or less after surface treatment is used to obtain a composite material. In this case, the volume average particle diameter (D50) is preferably 3 μm or less, and more preferably 1.5 μm or less, from the viewpoint that the effect of the present invention is easily obtained. The volume average particle size (D50) is preferably 100 nm or more, more preferably 200 nm or more, and further preferably 500 nm or more.

  In the present invention, the volume average particle diameter (D50) is measured by a laser scattering method (for example, using LS230 manufactured by Beckman Coulter as a measuring device and using ethanol as a dispersion medium). In the measurement, 0.01 to 1 g of a measurement sample was added to 5 ml of ethanol as a dispersion medium, and then the liquid in which the sample was suspended was subjected to dispersion treatment with an ultrasonic disperser for about 1 to 5 minutes. What is necessary is just to measure the particle size distribution of the particle of the particle size of the range. For the particle size range (channel) divided based on the particle size distribution measured in this manner, the volume is drawn from the small diameter side to the cumulative distribution, and the particle size that becomes 50% cumulative is the volume average particle size (D50). ).

  Any known coupling agent can be used without any particular limitation, and examples thereof include silane coupling agents, zirconate coupling agents, aluminate coupling agents, titanate coupling agents, and the like. Among these coupling agents, a silane coupling agent is preferable from the viewpoint of reactivity with a silica-based metal oxide which is a preferable metal oxide.

  The following general formula (I) is mentioned as a suitable silane coupling agent.

R ¹ —SiR ² mBn (I)
In the general formula (I), R ¹ is an organic group having 2 to 30 atoms constituting the straight chain portion, having an ethylenically unsaturated group, a methyl group, or an aromatic group at the terminal, and R ² is It is a C1-C6 hydrocarbon group, B is an alkoxy group, a halogeno group, or an isocyanate group which has a C1-C6 hydrocarbon group. Here, m and n are integers, the sum of m and n is 3, and m is an integer in the range of 0-2.

  Examples of ethylenically unsaturated groups include i) unsaturated aliphatic groups including vinyl groups, (meth) acryloxy groups, (meth) acrylamide groups, and ii) phenyl groups, phenoxy groups, phenylamino groups, and benzophenones. An aromatic group including a vinyl group, a (meth) acryloyl group, and a (meth) acrylamide group as a substituent of an aromatic group such as a group, a hydroxybenzophenone group, a biphenyl group, and a naphthyl group.

As the organic group having 2 to 30 atoms constituting the straight-chain part, having an ethylenically unsaturated group, methyl group, or aromatic group at the terminal in R ¹ , typically, an ethylenically unsaturated group , A methyl group, an aromatic group, or a group in which a linear alkylene group having 1 to 28 carbon atoms is bonded to these functional groups. In addition, in R ¹ , the atoms constituting the linear portion The number includes the number of atoms of the ethylenically unsaturated group, methyl group, or aromatic group indicated as the terminal. When the terminal is an aromatic ring, the number of atoms constituting the straight-chain part in this part is counted by the minimum number of atoms connecting the atoms that form the ring farthest from the carbon atom directly bonded to Si. And For example, in the case of a benzene ring, the minimum number of atoms that connect from the carbon atom directly bonded to Si to the atom that forms the ring farthest is directly bonded to Si to the carbon atom 4 that forms the benzene ring. A hydrogen atom bonded to the carbon atom constituting the ring farthest from the carbon atom is added and counted as 5.

By making the number of atoms of the straight chain portion of R ¹ 2-30, the affinity between the thermoplastic resin having a melting point or fluidization temperature of 300 ° C. or higher and the metal oxide surface-treated with the coupling agent is improved. It becomes easy. The number of atoms of the linear portion of R ¹ is more preferably 3-20, and further preferably 4-10.

Examples of the hydrocarbon group having 1 to 6 carbon atoms of R ² include hydrocarbon groups such as a methyl group, an ethyl group, and a propyl group.

  B is an alkoxy group having 1 to 6 carbon atoms, a halogeno group, or an isocyanate group, and examples of the alkoxy group having 1 to 6 carbon atoms include a methoxy group and an ethoxy group. Examples of the halogeno group include a chloro group and a bromo group. Among the alkoxy groups having 1 to 6 hydrocarbon groups, halogeno groups, or isocyanate groups represented by B, an alkoxy group is preferable from the viewpoint of easy reaction control.

  Preferable silane coupling agents include 11-methacryloyloxyundecylmethyldimethoxysilane, 10-methacryloyloxydecyltrimethoxysilane, 10-methacryloyloxydecylmethyldimethoxysilane, 10-methacryloyloxydecyltrichlorosilane, 8-methacryloyloxyoctyltri Methoxysilane, 8-methacryloyloxyoctylmethyldimethoxysilane, 8-methacryloyloxyoctyldimethylmethoxysilane, 8-methacryloyloxyoctyltrichlorosilane, 6-methacryloyloxyhexylmethyldimethoxysilane, 4-methacryloyloxybutyltrimethoxysilane, γ-methacryloyl Oxypropyltrimethoxysilane, γ-methacryloyloxypropylmethyldi Methoxysilane, γ-methacryloyloxypropyldimethylmethoxysilane, γ-methacryloyloxypropyltrichlorosilane, γ-methacryloyloxypropyltriisocyanatosilane, γ-methacryloyloxypropyldimethylisocyanatosilane, γ-methacryloyloxypropyltriethoxysilane, 3 -(4-Methacryloyloxyphenyl) propyltrimethoxysilane, 3- (4-methacryloyloxyphenyl) propyltrichlorosilane, 3- (4-methacryloyloxyphenyl) propyltriisocyanatosilane, styrylpropyltrimethoxysilane, 3- ( N-styrylmethyl-2-aminoethylamino) -propyltrimethoxysilane, (methacryloyloxymethyl) phenylbutyltrimethoxysilane Lan, O- (methacryloyloxyethyl) -N- (triethoxysilylpropyl) carbamate, N- (3-methacryloyloxy-2-hydroxypropyl) -3-aminopropyltriethoxysilane, acrylates of these methacrylate compounds, Butyltriethoxysilane, butyltrimethoxysilane, pentyltrimethoxysilane, hexyltrimethoxysilane, octyltrimethoxysilane, phenyltrimethoxysilane, phenoxypropyltrichlorosilane, phenoxypropylmethyldichlorosilane, phenoxypropyldimethylchlorosilane, benzoylpropyltrimethoxy Silane, phenylaminopropyltrimethoxysilane, 3-phenylpropylmethyldichlorosilane, 4-phenylbutyltrichlorosila 4-phenylbutylmethyldichlorosilane, 11-phenoxyundecyltrichlorosilane, 2-hydroxy-4- (3-triethoxysilylpropoxy) diphenylketone, 6-phenylhexyldimethylchlorosilane, N-1-phenylethyl-N ′ -Triethoxysilylpropylurea, 3- (4-methacryloyloxyphenyl) propyltrimethoxysilane, 3- (4-methacryloyloxyphenyl) propyltrichlorosilane, 3- (4-methacryloyloxyphenyl) propyltriisocyanatosilane, styryl Mention of propyltrimethoxysilane, 3- (N-styrylmethyl-2-aminoethylamino) -propyltrimethoxysilane, (methacryloyloxymethyl) phenylbutyltrimethoxysilane, etc. Can.

  The metal oxide surface-treated with the coupling agent used in the present invention is a weight loss rate from 120 ° C. to 800 ° C. (hereinafter referred to as “thermogravimetric analysis” performed at a heating rate of 10 ° C./min. , Which may be referred to as “thermal weight loss rate”) is 0.5% or less. By using a dental resin composite material containing a metal oxide surface-treated with a coupling agent having a thermal weight reduction rate of 0.5% or less, a dental member in which bubbles and discoloration / color unevenness are suppressed is produced. It becomes easy. For thermogravimetric analysis, any method can be used as long as the weight at 120 ° C. and the weight at 800 ° C. can be measured, but the weight of the sample at each temperature is continued while changing the sample temperature according to the program. Preferably, the measurement is performed using a thermogravimetric apparatus that can be measured automatically. It should be noted that the thermogravimetric measuring device can be used even if a differential thermal / thermogravimetric simultaneous measuring device (TG / DTA) that can measure simultaneously with the differential heat is used. By using a thermogravimetric measuring device, it is easy to perform thermogravimetric measurement starting from a specific temperature (120 ° C.) and to adjust the temperature rising rate.

  The thermogravimetric reduction rate was measured with a thermogravimetric apparatus by using 15 μg ± 5 μg of metal oxide surface-treated with a coupling agent, raising the temperature from room temperature (25 ° C.) to 800 ° C. at 10 ° C./min. And measuring the thermogravimetry at each temperature. Thereafter, the difference between the weight at 800 ° C. and the weight at 120 ° C. is calculated. From these measurement results, the thermal weight loss rate can be determined according to the following equation (2).

Thermal weight loss rate [%] = (Y−Z) / Z × 100 Formula (2)
Here, Y is the weight [μg] of the metal oxide surface-treated with the coupling agent at 800 ° C., and Z is the weight [μg] of the metal oxide surface-treated with the coupling agent at 120 ° C. .

  The thermal weight reduction rate of the metal oxide surface-treated with the coupling agent is more preferably 0.4% or less because the effect of improving bubbles is high.

  When the thermal weight reduction of the metal oxide surface-treated with the coupling agent is small, it means that the surface treatment with the coupling agent is not sufficiently performed, and the affinity between the resin and the metal oxide is improved. The thermal weight reduction rate is preferably 0.03% or more, more preferably 0.07% or more, and more preferably 0.1% or more. More preferably it is.

When treating the surface of the metal oxide with a coupling agent, the amount of coupling agent added during the surface treatment reaction is determined from the specific surface area of the metal oxide and the minimum coating area of the coupling agent (theoretical value). ) Is widely used. This is a method of calculating the optimum surface treatment agent amount (theoretical value) by dividing the product of the mass of the inorganic particles and the specific surface area of the inorganic particles by the minimum coating area of the surface treatment agent. That is, the addition amount of the coupling agent per 1 g of the metal oxide is X [g], the specific surface area of the metal oxide is A [m ² / g], and the minimum coating area of the coupling agent is B [m ² / g]. In general, the addition amount X of the coupling agent per 1 g of the metal oxide, which is the optimum surface treatment agent amount, is calculated as X = A / B. However, when a dental resin composite material is manufactured using a metal oxide that has been surface-treated with the addition amount of the coupling agent according to the above calculation method, the metal oxide surface-treated with the coupling agent The thermal weight reduction rate tends to exceed 0.5%, and when a dental member is produced using the dental resin composite material, bubbles and discoloration / color unevenness are likely to occur in the obtained dental member. Since it becomes easy to obtain a metal oxide surface-treated with a coupling agent having a thermal weight loss rate of 0.5% or less, the coupling agent per 1 g of metal oxide during the surface treatment of the metal oxide Assuming that X is added by X = (A / B) × C, the coefficient C is preferably 0.6 or less, and more preferably 0.5 or less. When the amount of the coupling agent is too small, it is difficult to obtain the advantage of performing the surface treatment that the affinity between the resin and the metal oxide can be improved, so that C is 0.05 or more. Is more preferable and 0.1 or more is more preferable.

When a metal oxide having a large specific surface area is used, the amount of metal oxide is determined according to the amount of coupling agent added during the surface treatment calculated from the specific surface area of the metal oxide and the minimum coating area of the coupling agent. As the amount of coupling agent increases, the thermal weight loss rate tends to increase. Therefore, in the case of a metal oxide that has been surface-treated by a commonly practiced method, the larger the specific surface area of the metal oxide, the more easily the bubbles and discoloration / color unevenness that are the problems of the present invention. Therefore, when the specific surface area of the metal oxide is large, in the composite material including the thermoplastic resin having a melting point or fluidization temperature of 300 ° C. or more and the metal oxide surface-treated with a coupling agent, the thermal weight reduction rate The effect of using a metal oxide that has been surface-treated with a coupling agent having an N of 0.5% or less is more pronounced. Therefore, the specific surface area of the metal oxide is preferably 3 m ² / g or more, and more preferably 10 m ² / g or more, from the viewpoint that the effect of the present invention is easily obtained. In addition, when the specific surface area is too large, the amount of the coupling agent required increases, so that the effect of the present invention may be limited. Therefore, the specific surface area is preferably 50 m ² / g or less, and 25 g / m ^2. The following is more preferable.

  As a method for surface-treating a metal oxide with a coupling agent, a known method can be used without any particular limitation. For example, a method of spraying a coupling agent while vigorously stirring the metal oxide with a stirring blade, a method of dispersing the metal oxide in an appropriate solvent, dissolving the coupling agent, and then removing the solvent, or The coupling agent is hydrolyzed with an acid catalyst in an aqueous solution to generate a functional group that reacts with a metal oxide such as a silanol group. After the coupling agent is attached to the surface of the metal oxide in the aqueous solution, spraying is performed. A method of removing water by a method such as drying, a method of dispersing a metal oxide in an appropriate dispersion medium, dissolving a coupling agent, performing a reflux, and then filtering and classifying and collecting inorganic particles. Can be mentioned. In any method, the reaction between the metal oxide and the coupling agent is usually promoted by heating preferably in the range of 50 ° C to 200 ° C, more preferably in the range of 100 ° C to 150 ° C. Can do.

  The particle size of the metal oxide surface-treated with the coupling agent is not particularly limited. However, since the specific surface area usually increases when the particle size is small, the above specific surface area of the metal oxide and the minimum coating of the coupling agent When the amount of the coupling agent added during the surface treatment calculated from the area is followed, the amount of the coupling agent relative to the metal oxide tends to increase, and the thermal weight loss rate tends to increase. That is, in the case of a metal oxide that has been surface-treated by a commonly practiced method, bubbles and discoloration / color unevenness, which are the problems of the present invention, are more likely to appear when the particle size of the metal oxide is smaller. Therefore, when the particle size of the metal oxide is small, in the composite material containing the thermoplastic resin having a melting point or fluidization temperature of 300 ° C. or more and the metal oxide surface-treated with a coupling agent, the thermal weight reduction rate The effect of using a metal oxide that has been surface-treated with a coupling agent having an N of 0.5% or less is more pronounced. Therefore, the particle diameter of the surface-treated metal oxide is preferably 3 μm or less, and preferably 1.5 μm or less, from the viewpoint that the effect of the present invention is easily obtained. Is more preferable. On the other hand, when the particle diameter of the surface-treated metal oxide is small, the viscosity of the metal oxide surface-treated with a coupling agent is blended with a thermoplastic resin having a melting point or fluidization temperature of 300 ° C. or higher. Since the increase tends to occur easily, it tends to be difficult to increase the blending amount. Therefore, the volume average particle diameter (D50) of the surface-treated metal oxide is preferably 100 nm or more, and preferably 200 nm or more. More preferably, it is more preferably 500 nm or more.

<Composition>
In the composite material of the present invention, the compounding amount of the metal oxide surface-treated with a coupling agent having a thermogravimetric reduction rate of 0.5% or less is not particularly limited, and metal oxidation usually added to the composite material as a filler Similar to the product, it may be appropriately determined depending on the application in consideration of the mechanical characteristics. Since it is easy to obtain physical properties such as mechanical properties suitable for dental use, it is preferably 10 parts by mass or more and 70 parts by mass or less, and 20 parts by mass or more and 50 parts by mass or less per 100 parts by mass of the composite material. It is more preferable that In addition, when the amount of the metal oxide surface-treated with the coupling agent is large, the amount of gas generated at the time of melt-kneading tends to increase. The effect of the present invention that a member can be produced is remarkably obtained. Therefore, the metal oxide surface-treated with a coupling agent having a thermal weight reduction rate of 0.5% or less is preferably blended in an amount of 10 parts by mass or more, preferably 15 parts by mass or more per 100 parts by mass of the composite material. It is more preferable that 20 parts by mass or more is further blended.

  In addition to the metal oxide surface-treated with a coupling agent, the composite material of the present invention contains inorganic particles such as pigments, antistatic agents, X-ray contrast materials, ultraviolet absorbers, and fluorescent agents. Also good. The blending amount of all inorganic fillers (hereinafter also simply referred to as inorganic fillers), which are a combination of the metal oxide surface-treated with these coupling agents and other inorganic particles, is a viewpoint that makes it easy to obtain appropriate physical properties as a dental material. From 100 parts by mass of the composite material, it is preferably in the range of 10 parts by mass to 70 parts by mass, more preferably in the range of 15 parts by mass to 60 parts by mass, and in the range of 20 parts by mass to 50 parts by mass. More preferably it is. By setting the blending amount of the inorganic filler to 10 parts by mass or more, it becomes easy to obtain physical properties such as mechanical properties suitable for dental use. Further, by setting the blending amount to 70 parts by mass or less, when melt-kneading a thermoplastic resin having a melting point or fluidization temperature of 300 ° C. or more and an inorganic filler, an increase in viscosity is suppressed and handling becomes easy. At the same time, it becomes easy to improve the dispersibility of the particle component.

  A metal oxide surface-treated with a coupling agent having a thermal weight reduction rate exceeding 0.5% may be blended, but if the amount is blended in a large amount, the effect of the present invention is limited. 10 parts by mass or less per part, preferably 5 parts by mass or less, more preferably 1 part by mass or less.

<Manufacturing method>
If the melting point or fluidization temperature is 300 ° C. or higher and the inorganic filler such as a metal oxide surface-treated with a coupling agent can be uniformly mixed, the method for producing the composite material can be used. Any method may be used, but it is usually carried out by melt kneading, in which an inorganic filler is blended into a melted thermoplastic resin and kneaded. The melt-kneading can easily combine a thermoplastic resin having a melting point or fluidization temperature of 300 ° C. or more with an inorganic filler, and a metal oxide having a thermal weight reduction rate of 0.5% or less. Since a composite material that can easily obtain the effect of the present invention that the generation of bubbles and discoloration / color unevenness can be obtained by using it can be mentioned as a preferred production method.

  As a technique for performing melt kneading, a known technique can be used without particular limitation. For example, melt kneading with a mixer equipped with a heating device, an extruder (single-axis melt kneading apparatus, biaxial melt kneading apparatus, triaxial melting) Melt kneading using a kneading apparatus, a four-axis melt kneading apparatus, or the like). Among these, melt kneading by an extruder which can be continuously manufactured and easy to obtain a granular (pellet-shaped) composite material that can be easily handled in the next process is preferable, and melt kneading by a biaxial melt kneading apparatus is most preferred. preferable.

  What is necessary is just to determine suitably the conditions which melt-knead according to each sample. When the kneading temperature is too low, it is difficult to uniformly mix the inorganic filler with a high viscosity of the thermoplastic resin, and overloading at the time of kneading may cause a failure of the apparatus or deterioration of the sample. The above is preferable. On the other hand, when the kneading temperature is too high, deterioration of the thermoplastic resin due to high temperature may occur. In addition, the organic component of the coupling agent of the metal oxide surface-treated with the coupling agent is excessively volatilized or lost, and the dispersibility due to the surface treatment of the metal oxide with the coupling agent is reduced. While the improvement effect is difficult to obtain, bubbles may be generated in the composite material, and the effect of the present invention may be limited. Therefore, the kneading temperature is preferably 500 ° C. or less, and more preferably 450 ° C. or less.

  The shape of the composite material of the present invention after the melt-kneading can be any shape such as a strand shape, a pellet shape, a powder shape, a block shape, an ingot shape, and a sheet shape, as long as a dental member having a desired shape can be produced. However, it is preferably a pellet shape (particularly a cylindrical shape having a diameter of about 0.5 mm to 5 mm and a length of about 1 mm to 10 mm) from the viewpoint of ease of handling. The pellet-shaped composite material is obtained by extruding a composite material extruded in a strand form from an extruder (single-axis melt kneader, biaxial melt kneader, triaxial melt kneader, four-axis melt kneader, etc.) at a desired interval. It can be easily obtained by cutting.

<Application>
The composite material of the present invention can be used as a dental member. The use is not particularly limited, and for example, it can be suitably used for dentures, artificial teeth, denture bases, dental implants (fixtures, abutments, superstructures), crown restoration materials, abutment building materials, etc. .

  When a composite material obtained by melt kneading is used for dental applications, a method for forming a dental member having a desired shape includes hot press molding, injection molding, extrusion molding, additive manufacturing, cutting, and adhesive. A known method such as bonding can be used without particular limitation.

  Among these molding methods, hot press molding is mentioned as one of preferable methods because the effect of the present invention can be easily obtained and a dental member having a desired shape can be easily obtained. In hot press molding, a mold of a dental member having a desired shape is prepared, a composite material that has been melted or semi-molten by heating is placed therein, and the composite material is filled into the mold by applying pressure. Then, after cooling and hardening a composite material, it can take out and can obtain the dental member of a desired shape. Usually, a pellet-shaped composite material is often used from the viewpoint of ease of handling, but when the composite material before heating and melting contains a large amount of air bubbles, the dental member after molding has air bubbles. It tends to remain, or discoloration / color unevenness is likely to occur. Therefore, it is particularly preferable to use the composite material of the present invention with few bubbles as the composite material before heating and melting. The same applies to the case where the ingot-shaped composite material is molded into a desired shape by hot press molding. It is possible to manufacture any dental member by making it into a desired shape by hot press molding. However, by using the composite material of the present invention, highly irregular dentistry with highly suppressed color unevenness. Since it is easy to manufacture a dental member, it is preferable to manufacture a dental member for use in a dental prosthesis (such as a denture, artificial tooth, and crown restoration material) that requires particularly high aesthetics.

  Also, a molding method such as injection molding or extrusion molding, in which a composite material heated and melted is transferred with a screw, then filled in a mold, and cooled to obtain a predetermined shape is also provided by the present invention. It is mentioned as one of the preferable methods from the point of being easy to acquire the effect of this, and the point of handleability. When a screw is used, normally, bubbles are easily removed because the molten material is agitated. However, when a large amount of composite material is used, a large amount of bubbles are present in the composite material before heating and melting. When it is contained, it becomes difficult to sufficiently remove the bubbles, and the bubbles are likely to remain in the dental member after molding or discoloration / color unevenness is likely to occur. This method can be used to form dental parts of desired shapes such as dentures, artificial teeth, denture bases, dental implants, crown restoration materials, and abutment building materials, and can be used for cutting with CAD / CAM systems. It is possible to produce a dental treatment material for producing the dental member such as a block disk. Among these moldings, in particular, in the case of a thick molded body having a thickness of 10 mm or more, bubbles are not easily removed when filling the mold, and bubbles and discoloration / color unevenness are likely to occur in the molded body. Become. Therefore, it is particularly preferable to use the composite material of the present invention when molding a dental treatment material having a portion having a thickness of 10 mm or more, for example, a block disk used for cutting by a CAD / CAM system.

When molding using the composite material of the present invention, if the viscosity of the composite material is high, it is relatively difficult to remove bubbles remaining in the composite material before melting during molding. When using a material, the effect of using the composite material of the present invention is more remarkable. Therefore, based on the ISO1133, temperature 380 ° C., is a melt volume rate of the composite material, measured with a load 5 kgf ^(MVR), preferably at 50 cm 3 / 10min or ^less, more preferably at most 40 cm 3 / 10min, still more preferably 30 cm ³ / 10min or ^less, still more preferably less 20 cm 3 / 10min.

  When the whiteness of the color tone of the composite material is high, it is preferable from an aesthetic point of view in dental use, particularly in restoration of a crown, but it becomes conspicuous when color unevenness occurs. Therefore, it is preferable that the whiteness of the composite material is high because the effects of the present invention are more likely to appear. The color tone of the composite material when measured under a black background using a color difference meter and expressed in the CIELab color system is preferably L * of 65 or more, more preferably 70 or more, and 75 or more. More preferably it is.

  EXAMPLES Hereinafter, although an Example demonstrates this invention concretely, this invention is not restrict | limited to these Examples. The abbreviations and titles shown in the examples are as follows.

[A thermoplastic resin having a melting point or fluidization temperature of 300 ° C. or higher]
PEEK: Polyetheretherketone (Daicel Evonik Co., Ltd .: VESTAKEEEP2000G, melting point 340 ° C.)

[Metal oxide]
F1: Silica (spherical, average volume particle size 1 μm, BET specific surface area 11 m ² / g)
F2: Silica (spherical, average volume particle size 0.5 μm, BET specific surface area 13.5 m ² / g)
F3: Silica (spherical, average volume particle size 5 μm, BET specific surface area 3 m ² / g)

[Coupling agent]
MPS: γ-methacryloyloxypropyltrimethoxysilane (minimum covering area 299 m ² / g)
OTS: Octyltrimethoxysilane (minimum covering area 333 m ² / g)
FTS: phenyltrimethoxysilane (minimum covering area 394 m ² / g)

  Each test method is as follows.

(Thermogravimetric analysis of metal oxide surface-treated with a coupling agent)
15 μg of the metal oxide surface-treated with the coupling agent was heated to 10 ° C./min in the atmosphere by using a differential thermothermal gravimetric simultaneous measurement apparatus (SII Nano Technology Co., Ltd .: EXSTAR TG / DTA6300). The temperature was raised, and the weight at each temperature in the range of 50 ° C. to 800 ° C. was measured. The thermal weight loss rate was calculated from the obtained weight at each temperature.

(Evaluation of bubbles in dental parts (or molded resin composite materials))
The cut surface obtained by cutting the formed composite material near the center was visually observed, and the state of bubbles was evaluated according to the following criteria.
A: Five samples were evaluated, and no bubbles were observed in all samples.
B: Five samples were evaluated, and no bubbles were observed in three or more samples.
C: Five samples are evaluated, and there are less than two samples in which bubbles are not observed.
D: Five samples are evaluated, and bubbles are observed in all samples.
E: Evaluating 5 samples, all samples show a greater number of bubbles than D.

(Evaluation of discoloration of dental material (or molded resin composite material))
The color tone of the appearance of the composite material molded by injection molding was visually compared with the color tone of the pellet state, and evaluated according to the following criteria.
A: A molded product in which a large change in color tone was not seen as compared with the pellet state was obtained.
B: Compared to the pellet state, molded bodies having greatly different color tones were obtained.

(Metal oxide surface treatment method)
After 300 g of metal oxide and 500 g of toluene were weighed and mixed, a slurry dispersed using a homogenizer was prepared. Next, after the slurry was put into a three-necked flask equipped with a reflux condenser, a predetermined amount of a coupling agent was further added. The predetermined amount was determined by the product of the value X = (A / B) × C and the amount (300 g) of the surface-treated metal oxide. Subsequently, the solution in the three-necked flask was heated to reflux for 2 hours while stirring. Subsequently, the solid content was separated from the heated and refluxed solution using a centrifuge. Then, this solid content was washed twice with toluene, and then dried at 90 ° C. for 10 hours in a vacuum dryer. Thereby, the metal oxide surface-treated with the coupling agent was obtained.

(Method for preparing a composite material comprising a thermoplastic resin having a melting point or fluidization temperature of 300 ° C. or higher and a metal oxide surface-treated with a coupling agent)
A predetermined amount of melting point or fluidizing temperature of 300 ° C. or higher thermoplastic resin and a metal oxide surface-treated with a coupling agent are charged into a biaxial melt kneader and melted at a barrel temperature of 360 ° C. and a rotation speed of 500 rpm. Kneading was performed. The strand discharged from the nozzle was cooled in a water tank, and then a pelletizer was used to obtain a cylindrical pellet having a diameter of about 1 to 3 mm and a length of about 2 to 4 mm.

(Molding of composite material by hot press molding)
A mold was obtained by burying molar crown-shaped wax in gypsum and burning the wax by heat treatment. The composite material pellets were put into the mold, heated to about 400 ° C. and held for 20 minutes to plasticize the composite material. Pressing was performed at 400 ° C. with a heat and pressure molding machine (hot press machine: TD-PF1 manufactured by Tokuyama Dental Co., Ltd.), the composite material was pressed into the mold, held for 5 minutes, and then cooled to room temperature. After cooling, the molded composite material was taken out from the gypsum.

(Molding of composite material by injection molding)
A mold unit provided with a 12 × 14 × 18 mm cavity was installed in an injection molding machine SE18DUZ (manufactured by Sumitomo Heavy Industries, Ltd.). The composite material is put into a hopper with a pre-dryer, the molding temperature (cylinder temperature) is set to 360 to 400 ° C., the fluidization temperature is 360 ° C., the mold temperature is set to 180 ° C., the injection pressure is 180 MPa, and the injection speed is 50 mm / sec. Injection filling was performed under the conditions. A pressure holding pressure of 180 MPa was maintained for 40 seconds. After 300 seconds of cooling time by the mold, the mold unit was opened and the resin block was taken out.

<Example 1>
A surface treatment was performed using 3002 g of the coupling agent MPS (calculated as C = 0.6 in the formula (1)) with respect to 300 g of the metal oxide F1, and the thermal weight reduction rate was 0.48. A metal oxide surface-treated with a ring agent was prepared. 200 g of the metal oxide and 300 g of PEEK were melt-kneaded with a biaxial melt kneader, and the sample discharged in a strand shape was cut with a pelletizer to obtain a pellet of the composite material M1.

  The composite material M1 pellets are press-fitted into a molar crown mold by melting the composite material at 380 ° C. using a hot press molding machine (heat press) TD-PF1 (manufactured by Tokuyama Dental Co., Ltd.). The composite material thus formed was taken out after being kept for 1 hour in a room temperature environment with pressure applied.

  After observing the bubble and discoloration of the appearance of the molded composite material, cut it, observe the internal bubbles, and evaluate the bubbles (A to E) of the hot press-molded product from both the external and internal observation results. Were determined.

  Further, the pellets of the composite material M1 were molded into a block shape of 12 mm × 14 mm × 18 mm by injection molding, and the color tone of the appearance color tone (A, B) was compared with that of the pellets.

  Table 1 shows the composition of the composite material and each parameter of the metal oxide surface-treated with the coupling agent used, and Table 2 shows the evaluation results of bubbles and discoloration.

<Examples 2 and 3, Comparative Example 1>
Except having changed the value of C at the time of surface treatment into what was shown in Table 1, after obtaining the composite material according to Example 1, it shape | molded and evaluated the bubble and discoloration of a molded object.

<Examples 4 and 5, Comparative Examples 2 and 3>
Except for changing the type of filler used and the value of C when performing the surface treatment to those shown in Table 1, molding was performed after obtaining the composite material according to Example 1, and the evaluation of bubbles and discoloration of the molded body was performed. went.

<Examples 6 and 7>
Except for changing the type of coupling agent to be used and the value of C when performing surface treatment to those shown in Table 1, molding was performed after obtaining the composite material according to Example 1, and bubbles and discoloration of the molded body were obtained. Evaluation was performed.

<Examples 8 and 9>
Except that the composition of the composite material was as shown in Table 1, molding was performed after obtaining the composite material according to Example 1, and bubbles and discoloration of the molded body were evaluated.

  From the evaluation results, Examples 1 to 9 using metal oxides surface-treated with a coupling agent having a thermal weight reduction rate of 0.5% or less are couplings having a thermal weight reduction rate exceeding 0.5%. Compared with Comparative Examples 1 to 3 using a metal oxide surface-treated with an agent, a dental member with less bubbles during hot press molding and a dental treatment material with less discoloration during injection molding are obtained. It was. Moreover, Examples 2-7 using the metal oxide surface-treated with the coupling agent whose thermal weight reduction rate is 0.4% or less are coupling agents whose thermal weight reduction rate exceeds 0.4%. Compared with Examples 1, 8, and 9 using the surface-treated metal oxide, a dental member having fewer bubbles during hot press molding was obtained.

  Examples 2, 4 and 5 and Comparative Examples 1 to 3 have the same C value but different average volume particle sizes of the metal oxides. That is, in Examples 2, 4, and 5, the value of C is 0.5, and the average volume particle diameter of the metal oxide is 1 μm, 0.5 μm, and 5 μm, respectively. Is 1.0, and the average volume particle diameter of the metal oxide is 1 μm, 0.5 μm, and 5 μm, respectively. In Examples 2, 4, and 5 in which the value of C is 0.6 or less, the thermal weight reduction rate of the surface-treated metal oxide is 0.5% or less, and the state of bubbles in hot press molding was also excellent. Thing (A evaluation). On the other hand, in Comparative Examples 1 to 3 in which the value of C exceeds 0.6, the thermal weight reduction rate of the surface-treated metal oxide is more than 0.5%, and the state of bubbles in the hot press molding is also inferior. (E or D evaluation). Further, from Comparative Examples 1 to 3, even when surface treatment is performed under the same conditions with the same C value, if the average weight particle size is 3 μm or less when the thermal weight reduction rate is more than 0.5%, hot press molding In comparison with the case where the average volume particle size is more than 3 μm, Comparative Example 1 and 2 in which the average volume particle size is 3 μm or less are evaluated as E, and Comparative Example 3 larger than 3 μm is evaluated as D. ) On the other hand, from Examples 2, 4 and 5, when the thermal weight reduction rate is 0.5%, all are excellent (A evaluation) regardless of the average volume particle diameter. Thus, when the average volume particle size of the metal oxide is 3 μm or less, the metal oxide surfaced with a coupling agent having a thermogravimetric reduction rate of 0.5% or less as compared with the case of exceeding 3 μm. The degree to which the state of the bubbles can be improved by using is great, and the advantages of the present invention are great.

  Examples 1 to 3 and Comparative Example 1 differ only in the amount (C value) of the coupling agent used for the surface treatment of the metal oxide, and as a result, the thermal weight loss rate differs. When these are compared, in Comparative Example 1 in which the value of C exceeds 0.6, the thermal weight reduction rate of the surface-treated metal oxide exceeds 0.5%, and there are many bubbles in hot press molding. In Examples 1 to 3 having a value of 0.6 or less, the thermal weight reduction rate of the surface-treated metal oxide was 0.5% or less, and there were few bubbles. In Examples 2 and 3 in which the value of C was 0.5 or less, the thermal weight reduction rate of the surface-treated metal oxide was 0.4% or less, and no bubbles were observed. From this, by performing the surface treatment with the C value of 0.6 or less, the thermal weight reduction rate of the surface-treated metal oxide can be made 0.5% or less, and the dental member with few bubbles Further, by performing the surface treatment with the value of C being 0.5 or less, the thermal weight reduction rate of the surface-treated metal oxide can be 0.4% or less. It can be said that it is easy to obtain a dental member with few bubbles.

Claims (6)

  A composite material comprising a thermoplastic resin having a melting point or fluidization temperature of 300 ° C. or higher and a metal oxide surface-treated with a coupling agent, the surface-treated metal oxide rising in an air atmosphere. A dental resin composite characterized in that it is a surface-treated metal oxide having a weight reduction rate of 120% to 800 ° C by thermogravimetric analysis performed at a temperature rate of 10 ° C / min. .   The dental resin composite material according to claim 1, wherein the average volume particle diameter of the metal oxide is in the range of 0.1 µm to 3 µm.   The dental resin composite material according to claim 1 or 2, wherein the content of the metal oxide is in the range of 20 to 60% by mass of the dental resin composite material. A composition comprising a metal oxide subjected to surface treatment with a coupling agent under conditions satisfying the following formula (1), and the surface-treated metal oxide and a thermoplastic resin having a melting point or fluidization temperature of 300 ° C. or higher. 2. The method for producing a dental resin composite material according to claim 1, wherein kneading is carried out under conditions of 350 to 450 ° C.
X [g] = (A / B) × C (1)
(Wherein X is the amount of coupling agent added per gram of metal oxide, A is the specific surface area of the metal oxide [m ² / g], B is the minimum coating area of the coupling agent [m ² / g], The coefficient C is 0.05 to 0.6)   The manufacturing method of a dental prosthesis which produces a dental prosthesis by heat-press-molding the dental resin composite material in any one of Claims 1-3.   The manufacturing method of the dental treatment material which manufactures the dental treatment material of thickness 10mm or more by injection-molding or extrusion-molding the dental resin composite material in any one of Claims 1-3.