JP2021147360A - Production method of inorganic organic composite medical science material - Google Patents

Abstract

To provide a production method of an inorganic organic composite medical science material capable of forming an inorganic material into a desired shape, and improving production efficiency of the inorganic organic composite medical science material.SOLUTION: A production method of a nano composite resin 1 is configured so that, after dispersing inorganic nano particles 23 into a liquid material 20 including a hydroxy group-containing photo-polymerizable monomer, a polyoxyalkylene group-containing photo-polymerizable monomer, and alcohol, then the hydroxy group-containing photo-polymerizable monomer and polyoxyalkylene group-containing photo-polymerizable monomer are subjected to photo polymerization, for preparing a particle dispersion 24 in which the inorganic nano particles 23 are dispersed in a polymer matrix 25. Then, the alcohol 27 is removed from the particle dispersion 24, then the particle dispersion 24 is burned, for forming an inorganic material 2 including a communication hole 22. An organic polymer 3 is filled in the communication hole 22, for producing a nano composite resin 1.SELECTED DRAWING: Figure 2

Description

The present invention relates to a method for producing an inorganic-organic composite medical material.

In medical treatment, it is known to supplement the morphology and function of a defective part of the human body with an artificial object (prosthodontics). For example, in dental treatment, a crown missing due to tooth decay or the like is repaired with a dental material. As such a dental material, a composite material of an inorganic material and an organic material is being studied in order to secure the required mechanical properties.

However, the dental material that restores the crown comes into contact with the enamel of the opposing tooth (natural human enamel) in occlusion. At this time, if the hardness of the dental material is smaller than the enamel, the dental material is worn (attrition), and if the hardness of the dental material is larger than the enamel, the enamel of the opposing tooth is worn (attrition). )do. Therefore, a composite material having a hardness comparable to that of enamel is desired.

As such a composite material, for example, an inorganic-organic composite medical material having a two-phase co-continuous structure of an inorganic substance having a communication hole and an organic polymer filled in the communication hole has been proposed (for example, an inorganic-organic composite medical material). See Patent Document 1).

In such an inorganic-organic composite medical material, inorganic nanoparticles and a water-soluble polymer are blended in a dispersion medium, and the inorganic nanoparticles are dispersed in the dispersion medium to prepare an inorganic particle dispersion liquid, and then the inorganic particle dispersion liquid is prepared. To prepare a gel-like porous precursor, and then the porous precursor is fired to form an inorganic fired body having communication holes, and then an organic polymer is formed in the communication holes of the inorganic fired body. Manufactured by filling.

International Publication No. 2018/212321

However, the method for producing an inorganic-organic composite medical material described in Patent Document 1 has a limit in improving the production efficiency of the inorganic-organic composite medical material, and the inorganic-organic composite medical material has a desired shape. Is difficult to form.

Therefore, the present invention provides a method for producing an inorganic-organic composite medical material, which can improve the production efficiency of the inorganic-organic composite medical material while forming an inorganic substance in a desired shape.

The present invention [1] is a method for producing an inorganic-organic composite medical material having a two-phase co-continuous structure of an inorganic substance having communication holes and an organic polymer filled in the communication holes, wherein the hydroxyl group-containing light A step of preparing a liquid material containing a polymerizable monomer, a polyoxyalkylene group-containing photopolymerizable monomer, and alcohols, a step of dispersing inorganic nanoparticles in the liquid material, and the hydroxyl group-containing photopolymerizable monomer. And the polyoxyalkylene group-containing photopolymerizable monomer are photopolymerized, and the inorganic nanoparticles are dispersed in a polymer matrix of the hydroxyl group-containing photopolymerizable monomer and the polyoxyalkylene group-containing photopolymerizable monomer. A step of preparing a dispersion, a step of removing the alcohols from the particle dispersion, a step of firing the particle dispersion from which the alcohols have been removed to form an inorganic substance having communication holes, and the above-mentioned It includes a method for producing an inorganic-organic composite medical material, which comprises a step of filling the communication holes of an inorganic substance with an organic polymer.

According to such a method, inorganic nanoparticles are dispersed in a liquid material containing a hydroxyl group-containing photopolymerizable monomer, a polyoxyalkylene group-containing photopolymerizable monomer (hereinafter referred to as a monomer component), and alcohols. Let me. Then, the monomer components are photopolymerized to prepare a particle dispersion in which the inorganic nanoparticles are dispersed in the polymer matrix. Therefore, the particle dispersion can be formed into a desired shape by photopolymerization of the monomer component.

Then, alcohols are removed from the particle dispersion having a desired shape, and the particle dispersion is calcined to form an inorganic substance having communication holes. Therefore, the inorganic material has the same desired shape as the particle dispersion. Then, the communication holes of the inorganic substance are filled with an organic polymer to produce an inorganic-organic composite medical material.

As a result, it is possible to improve the production efficiency of the inorganic-organic composite medical material while forming the inorganic substance into a desired shape.

According to the present invention [2], in the step of dispersing the inorganic nanoparticles in the liquid material, the dispersion ratio of the inorganic nanoparticles is 20% by mass or more with respect to the total of the liquid material and the inorganic nanoparticles. The method for producing an inorganic-organic composite medical material according to the above [1] is included.

According to such a method, since the dispersion ratio of the inorganic nanoparticles is equal to or higher than the above lower limit, poor formation of the inorganic substance can be stably suppressed.

According to the present invention [3], in the step of dispersing the inorganic nanoparticles in the liquid material, the dispersion ratio of the inorganic nanoparticles is 60% by mass or less with respect to the total of the liquid material and the inorganic nanoparticles. The method for producing an inorganic-organic composite medical material according to the above [1] or [2] is included.

According to such a method, since the dispersion ratio of the inorganic nanoparticles is not more than the above upper limit, the particle dispersion can be stably formed into a desired shape, and the defective formation of the inorganic substance can be suppressed more stably.

The present invention [4] includes the method for producing an inorganic-organic composite medical material according to any one of the above [1] to [3], wherein the average primary particle size of the inorganic nanoparticles is 40 nm or more. I'm out.

According to such a method, since the average primary particle diameter of the inorganic nanoparticles is at least the above lower limit, the inorganic nanoparticles can be stably dispersed in the liquid material, and the dispersion ratio of the inorganic nanoparticles is at least the above lower limit. Can be adjusted stably.

The present invention [5] includes the method for producing an inorganic-organic composite medical material according to any one of the above [1] to [4], wherein the inorganic nanoparticles have a spherical shape.

According to such a method, since the inorganic nanoparticles have a spherical shape, the moldability of the particle dispersion can be improved.

In the present invention [6], the content ratio of the hydroxyl group-containing photopolymerizable monomer in the liquid material is 75% by mass with respect to the total of the hydroxyl group-containing photopolymerizable monomer and the polyoxyalkylene group-containing photopolymerizable monomer. The method for producing an inorganic-organic composite medical material according to any one of the above [1] to [5], which is 98% by mass or less.

According to such a method, since the content ratio of the hydroxyl group-containing photopolymerizable monomer is at least the above lower limit, poor formation of inorganic substances can be suppressed more stably. Further, since the content ratio of the hydroxyl group-containing photopolymerizable monomer is not more than the above upper limit, the hardness of the inorganic-organic composite medical material can be stably adjusted within a desired range.

According to the method for producing an inorganic-organic composite medical material of the present invention, it is possible to improve the production efficiency of the inorganic-organic composite medical material while forming an inorganic substance in a desired shape.

FIG. 1 shows a schematic plan view of a nanocomposite resin as an embodiment of an inorganic-organic composite medical material produced by the method for producing an inorganic-organic composite medical material of the present invention. FIG. 2A is an explanatory diagram for explaining the method for producing the nanocomposite resin shown in FIG. 1, and shows a step of dispersing inorganic nanoparticles in a liquid material. FIG. 2B shows a step of photopolymerizing a monomer component to prepare a particle dispersion in which inorganic nanoparticles are dispersed in a polymer matrix, following FIG. 2A. FIG. 2C shows a step of firing the particle dispersion to form an inorganic substance, following FIG. 2B. FIG. 2D shows a step of filling the communication holes of the inorganic substance with the organic polymer, following FIG. 2C.

<Manufacturing method of inorganic-organic composite medical material>
A method for producing a nanocomposite resin 1 as an embodiment of a method for producing an inorganic-organic composite medical material of the present invention will be described with reference to FIGS. 1 to 2D.

As shown in FIG. 1, the nanocomposite resin 1 has a two-phase co-continuous structure of an inorganic substance 2 having a communication hole 22 and an organic polymer 3 filled in the communication hole 22. In the nanocomposite resin 1, the inorganic substance 2 and the organic polymer 3 are three-dimensionally continuous, respectively. The inorganic substance 2 and the organic polymer 3 may be phase-separated from each other, or may be chemically bonded to each other by a grafting treatment or the like.

As shown in FIGS. 2A to 2D, the method for producing the nanocomposite resin 1 includes a step of preparing a liquid material 20 containing a monomer component and alcohols, and an inorganic particle 23 in which the inorganic nanoparticles 23 are dispersed in the liquid material 20. A step of preparing the dispersion liquid 26, a step of photopolymerizing the monomer components to prepare a particle dispersion 24 in which the inorganic nanoparticles 23 are dispersed in the polymer matrix 25, and a step of removing alcohols from the particle dispersion 24. , A step of firing the particle dispersion 24 to form the inorganic substance 2 and a step of filling the communication holes 22 of the inorganic substance 2 with the organic polymer 3 are included in order.

(1) Step of preparing liquid material As shown in FIG. 2A, in order to prepare the liquid material 20, the monomer component and alcohols are mixed.

The monomer component contains at least a hydroxyl group-containing photopolymerizable monomer and a polyoxyalkylene group-containing photopolymerizable monomer.

When the monomer component contains a hydroxyl group-containing photopolymerizable monomer, the viscosity of the inorganic particle dispersion 26 can be adjusted within a suitable range, and the particle dispersion 24 can be formed into a desired shape. When the monomer component contains a polyoxyalkylene group-containing photopolymerizable monomer, poor formation of the inorganic substance 2 (for example, cracks) can be suppressed.

The hydroxyl group-containing photopolymerizable monomer has a photopolymerizable group and a hydroxyl group in the molecule.

The photopolymerizable group is located at one end in the molecule of the hydroxyl group-containing photopolymerizable monomer, for example.

The photopolymerizable group contains an ethylenically unsaturated double bond. Examples of the photopolymerizable group include (meth) acryloyloxy group, (meth) acryloylamide group, vinyl group, vinyl cyanide group and the like, and (meth) acryloyloxy group is preferable. That is, the hydroxyl group-containing photopolymerizable monomer preferably contains a (meth) acryloyloxy group. The (meth) acryloyl includes methacryloyl and / or acryloyl.

The number of functional groups of the photopolymerizable group in the hydroxyl group-containing photopolymerizable monomer is, for example, 1 or more, for example, 4 or less, preferably 2 or less.

The hydroxyl group is located, for example, in the molecule of the hydroxyl group-containing photopolymerizable monomer at the end opposite to the hydroxyl group (the other end). The number of functional groups of a hydroxyl group in a hydroxyl group-containing photopolymerizable monomer is, for example, 1 or more, for example, 4 or less, preferably 2 or less.

The molecular weight of the hydroxyl group-containing photopolymerizable monomer is, for example, 70 or more, preferably 120 or more, for example, 500 or less, preferably 300 or less.

As the hydroxyl group-containing photopolymerizable monomer, for example, a hydroxyl group-containing mono (meth) acrylate (for example, 2-hydroxyethyl (meth) acrylate, 6-hydroxyhexyl (meth) acrylate, 10-hydroxydecyl (meth) acrylate, propylene glycol mono). (Meta) acrylate, dihydroxypropyl mono (meth) acrylate, glycerin mono (meth) acrylate, erythritol mono (meth) acrylate, etc.), hydroxyl group-containing di (meth) acrylate (for example, 2,2-bis [4- (3- (3-) 3-) (Meta) acryloyloxy-2-hydroxypropoxy) phenyl] propane, 1,2-bis [3- (meth) acryloyloxy-2-hydroxypropoxy] ethane, pentaerythritol di (meth) acrylate, 2-hydroxy 1,3 -Dimethacryloxypropane, etc.), hydroxyl group-containing (meth) acrylamide (for example, N-hydroxyethyl (meth) acrylamide, N, N- (dihydroxyethyl) (meth) acrylamide, etc.) and the like.

The hydroxyl group-containing photopolymerizable monomer can be used alone or in combination of two or more.

Among such hydroxyl group-containing photopolymerizable monomers, hydroxyl group-containing mono (meth) acrylate is preferable, 2-hydroxyethyl (meth) acrylate is more preferable, and 2-hydroxyl (meth) acrylate is more preferable. Ethyl methacrylate (HEMA) can be mentioned.

The content ratio of the hydroxyl group-containing photopolymerizable monomer is, for example, 50.0% by mass or more, preferably 70.0% by mass, based on the total of the hydroxyl group-containing photopolymerizable monomer and the polyoxyalkylene group-containing photopolymerizable monomer. As described above, more preferably 75.0% by mass or more, further preferably 80.0% by mass or more, for example, 99.5% by mass or less, preferably 99.0% by mass or less, more preferably 98. It is 0% by mass or less.

When the content ratio of the hydroxyl group-containing photopolymerizable monomer is at least the above lower limit, the poor formation of the inorganic substance 2 can be suppressed more stably. Further, when the content ratio of the hydroxyl group-containing photopolymerizable monomer is not more than the above upper limit, the hardness of the nanocomposite resin 1 can be stably adjusted within a desired range (described later).

The polyoxyalkylene group-containing photopolymerizable monomer has the above-mentioned photopolymerizable group and a polyoxyalkylene group in the molecule.

The above-mentioned photopolymerizable group is located, for example, at at least one of both ends of the molecule of the hydroxyl group-containing photopolymerizable monomer, and preferably located at both ends of the molecule of the hydroxyl group-containing photopolymerizable monomer. The number of functional groups of the photopolymerizable group in the polyoxyalkylene group-containing photopolymerizable monomer is, for example, 1 or more, preferably 2 or more, for example, 4 or less, preferably 3 or less.

When the polyoxyalkylene group-containing photopolymerizable monomer has a plurality of photopolymerizable groups, the plurality of photopolymerizable groups may have only one type of photopolymerizable group and two or more types of photopolymerizable groups. It may have a group. The plurality of photopolymerizable groups preferably have only one type of photopolymerizable group.

The photopolymerizable group of the polyoxyalkylene group-containing photopolymerizable monomer is preferably the same as the photopolymerizable group of the hydroxyl group-containing photopolymerizable monomer. Among the above-mentioned photopolymerizable groups, a (meth) acryloyloxy group is preferable.

The polyoxyalkylene group is at least two consecutive oxyalkylene groups. The polyoxyalkylene group is continuous with the photopolymerizable group, for example, in the molecule of the hydroxyl group-containing photopolymerizable monomer. When the photopolymerizable group is located at both ends of the molecule of the hydroxyl group-containing photopolymerizable monomer, the polyoxyalkylene group is located between the two photopolymerizable groups.

The number of oxyalkylene groups contained in the polyoxyalkylene group is, for example, 2 or more, preferably 3 or more, for example, 9 or less, preferably 4 or less.

Examples of the oxyalkylene group include an oxyalkylene group having 1 to 4 carbon atoms, preferably an oxyethylene group and an oxypropylene group, and more preferably an oxyethylene group.

The polyoxyalkylene group may have only one kind of oxyalkylene group or may have two or more kinds of oxyalkylene groups. The polyoxyalkylene group preferably has only one type of oxyalkylene group.

The molecular weight of the polyoxyalkylene group-containing photopolymerizable monomer is, for example, 100 or more, preferably 200 or more, for example, 600 or less, preferably 400 or less.

Examples of the polyoxyalkylene group-containing photopolymerizable monomer include polyoxyethylene group-containing di (meth) acrylate (for example, triethylene glycol di (meth) acrylate, tetraethylene glycol di (meth) acrylate, and nonaethylene glycol di (meth). ) Acrylate, etc.), polyoxyethylene group-containing (meth) acrylamide, polyoxypropylene group-containing di (meth) acrylate, and the like.

The polyoxyalkylene group-containing photopolymerizable monomer can be used alone or in combination of two or more.

Among the polyoxyalkylene group-containing photopolymerizable monomers, polyoxyethylene group-containing di (meth) acrylate is preferable, and triethylene glycol di (meth) acrylate is more preferable.

The content ratio of the polyoxyalkylene group-containing photopolymerizable monomer is, for example, 0.5% by mass or more, preferably 1.% by mass, based on the total of the hydroxyl group-containing photopolymerizable monomer and the polyoxyalkylene group-containing photopolymerizable monomer. 0% by mass or more, more preferably 2.0% by mass or more, for example, 50.0% by mass or less, preferably 30.0% by mass or less, more preferably 25.0% by mass or less, still more preferably. It is 20.0% by mass or less.

Further, the monomer component may contain, as an optional component, another photopolymerizable monomer (for example, (meth) acrylate containing no hydroxyl group and polyoxyethylene group) as long as the effect of the present invention is not impaired. ..

The content ratio of the other photopolymerizable monomers is, for example, 0 parts by mass or more, for example, 5 parts by mass or less, based on 100 parts by mass of the total of the hydroxyl group-containing photopolymerizable monomer and the polyoxyalkylene group-containing photopolymerizable monomer. Preferably, it is 1 part by mass or less.

Further, the monomer component more preferably does not contain other photopolymerizable monomers and is composed of a hydroxyl group-containing photopolymerizable monomer and a polyoxyalkylene group-containing photopolymerizable monomer.

Examples of the alcohols include primary to tertiary monohydric alcohols, and more specifically, aromatic alcohols, aliphatic alcohols and the like.

The aromatic alcohol is a monohydric alcohol containing an aromatic ring, and examples thereof include phenol, hydroxytoluene, biphenyl alcohol, phenoxyethanol, and benzyl alcohol.

The aliphatic alcohol is a monohydric alcohol having a linear or branched alkyl group, and is, for example, a linear aliphatic alcohol (for example, methanol, ethanol, 1-propanol, 1-butanol, 1). -Pentanol, 1-hexanol, 1-heptanol, etc.), branched fatty alcohols (eg, iso-propanol, iso-butanol, sec-butanol, tert-butanol, iso-pentanol, sec-pentanol, 2 -Ethylhexanol, etc.) and the like.

Alcohols can be used alone or in combination of two or more.

The alcohols preferably contain at least aromatic alcohols, more preferably contain aromatic alcohols and aliphatic alcohols, and even more preferably composed of aromatic alcohols and fatty alcohols. Further, as the aromatic alcohol, phenoxyethanol is preferable. The aliphatic alcohol preferably includes 1-propanol.

When the alcohols contain aromatic alcohol and aliphatic alcohol, the inorganic nanoparticles 23 can be more stably dispersed in the liquid material 20, and the dispersion ratio of the inorganic nanoparticles 23 (described later) can be improved. .. Therefore, the poor formation of the inorganic substance 2 can be stably suppressed.

When the alcohols contain aromatic alcohol and fatty alcohol, the content ratio of the aromatic alcohol in the alcohol is, for example, 5.0% by mass or more, preferably 10.0% by mass or more, for example, 40.0% by mass. % Or less, preferably 30.0% by mass or less, and the content ratio of the aliphatic alcohol in the alcohols is, for example, 60.0% by mass or more, preferably 70.0% by mass or more, for example, 95.0. It is mass% or less, preferably 90.0 mass% or less.

Then, the alcohols are mixed with the monomer component so as to have the following mixing ratio.

The mixing ratio of the alcohols is, for example, 80 parts by mass or more, preferably 90 parts by mass or more, for example, 120 parts by mass or less, preferably 110 parts by mass or less, based on 100 parts by mass of the monomer component.

As a result, the liquid material 20 is prepared.

The content ratio of the monomer component in the liquid material 20 is, for example, 15.0% by mass or more, preferably 25.0% by mass or more, for example, 75.0% by mass or less, preferably 65.0% by mass or less. ..

The content ratio of the hydroxyl group-containing photopolymerizable monomer in the liquid material 20 is, for example, 20.0% by mass or more, preferably 30.0% by mass or more, more preferably 40.0% by mass or more, for example, 70.0. It is mass% or less, preferably 60.0 mass% or less.

The content ratio of the polyoxyalkylene group-containing photopolymerizable monomer in the liquid material 20 is, for example, 0.1% by mass or more, preferably 0.5% by mass or more, more preferably 2.0% by mass or more, for example. It is 30.0% by mass or less, preferably 20.0% by mass or less, and more preferably 10.0% by mass or less.

The content ratio of alcohols in the liquid material 20 is, for example, 25.0% by mass or more, preferably 35.0% by mass or more, for example, 85.0% by mass or less, preferably 75.0% by mass or less. ..

(2) Step of Dispersing Inorganic Nanoparticles 23 in Liquid Material 20 Next, inorganic nanoparticles 23 are dispersed in liquid material 20 to prepare an inorganic particle dispersion liquid 26.

The inorganic nanoparticles 23 are raw materials for the inorganic substance 2 and are particles formed from the inorganic material.

The inorganic material is not particularly limited, and examples thereof include known inorganic substances used for medical materials. Examples of the inorganic material include metallic materials and non-metallic materials (ceramics).

Examples of the metal material include gold, silver, platinum, palladium, cobalt, chromium, titanium, aluminum, iron, and alloys thereof.

Examples of the non-metal material (ceramics) include metal oxides, carbides, nitrides, phosphates, sulfates, fluorides and the like.

Metal oxides include single metal oxides containing only one of metal elements (eg, Al, Ti, Zr, etc.) and semi-metal elements (eg, Si, B, Ge, etc.), and metal elements and semi-metal oxides. Includes composite metal oxides containing two or more of the metal elements.

Examples of the single metal oxide include silica (SiO ₂ ), titania (TiO ₂ ), alumina (Al ₂ O ₃ ), and zirconia (ZrO ₂ ). Examples of the composite metal oxide include silica-zirconia, silica-titania, silica-alumina, and alumina-zirconia.

Examples of the carbide include silicon carbide and the like. Examples of the nitride include silicon nitride and the like. Examples of the phosphate include calcium phosphate and hydroxyapatite. Examples of the sulfate include barium sulfate and the like. Examples of the fluoride include calcium fluoride, ytterbium fluoride, yttrium fluoride and the like.

The inorganic materials can be used alone or in combination of two or more.

Among the inorganic materials, a non-metal material is preferable, a metal oxide is more preferable, a single metal oxide is more preferable, and silica is particularly preferable.

Examples of the shape of the inorganic nanoparticles 23 include a spherical shape and an indefinite shape, and preferably a spherical shape.

When the inorganic nanoparticles 23 have a spherical shape, the moldability of the particle dispersion can be improved.

The inorganic nanoparticles 23 have a nano-order primary particle size. Specifically, the range (particle size distribution) of the primary particle size of the inorganic nanoparticles 23 is, for example, 5 nm or more, preferably 10 nm or more, for example, 120 nm or less, preferably 100 nm or less. The primary particle size of the inorganic nanoparticles 23 can be measured with a transmission electron microscope (TEM).

The average primary particle size of the inorganic nanoparticles 23 is, for example, 5 nm or more, preferably 10 nm or more, preferably 40 nm or more, for example, 150 nm or less, preferably 50 nm or less. The average primary particle diameter of the inorganic nanoparticles 23 can be measured by a transmission electron microscope (TEM).

When the average primary particle diameter of the inorganic nanoparticles 23 is at least the above lower limit, the inorganic nanoparticles 23 can be stably dispersed in the liquid material 20, and the dispersion ratio of the inorganic nanoparticles described later can be improved. .. Therefore, the poor formation of the inorganic substance 2 can be suppressed more stably. When the average primary particle diameter of the inorganic nanoparticles 23 is not more than the above upper limit, the thixotropy of the particle dispersion can be further improved, and the moldability of the particle dispersion can be improved.

The method for dispersing the inorganic nanoparticles 23 in the liquid material 20 is not particularly limited, and examples thereof include ultrasonic dispersion, a rotating revolution stirrer, a vacuum stirring defoamer, and dispersion with a stirrer. From the viewpoint of suppressing aggregation, ultrasonic dispersion is preferable.

As a result, the inorganic nanoparticles 23 are uniformly dispersed in the liquid material 20 without agglutinating with each other, and the inorganic particle dispersion liquid 26 is prepared.

The dispersion ratio of the inorganic nanoparticles 23 is, for example, 10% by mass or more, preferably 20% by mass or more, more preferably 40% by mass or more, still more preferably 40% by mass or more, based on the total of the liquid material 20 and the inorganic nanoparticles 23. , 50% by mass or more, particularly preferably 55% by mass or more, for example, 80% by mass or less, preferably 70% by mass or less, more preferably 60% by mass or less.

When the dispersion ratio of the inorganic nanoparticles 23 is not less than the above lower limit, poor formation of the inorganic substance 2 can be suppressed. When the dispersion ratio of the inorganic nanoparticles 23 is not more than the above upper limit, the particle dispersion 24 can be stably formed into a desired shape, and the poor formation of the inorganic substance 2 can be stably suppressed.

The viscosity (@ 25 ° C.) of the inorganic particle dispersion liquid 26 is, for example, 10 cP or more, preferably 1000 cP or more, for example, 30,000 cP or less, preferably 15,000 cP or less. The viscosity of the inorganic particle dispersion liquid 26 can be measured with a cone plate type viscometer.

When the viscosity of the inorganic particle dispersion liquid 26 is in the above range, the particle dispersion 24 can be stably formed in a desired shape by the forming method described later.

Further, the inorganic particle dispersion liquid 26 preferably contains a photopolymerization initiator together with the inorganic nanoparticles 23.

The photopolymerization initiator is a compound that is sensitized by light (for example, ultraviolet rays, visible light, etc.), and examples thereof include α-ketocarbonyl compounds and acylphosphine oxide compounds.

Examples of the α-ketocarbonyl compound include α-diketone (eg, diacetyl, benzyl, camphorquinone, etc.), α-ketoaldehyde (eg, methylglyoxal, phenylglyoxal, etc.), pyruvic acid, and the like.

Examples of the acylphosphine oxide compound include phenylbis (2,4,6-trimethylbenzoyl) phosphine oxide, 2,4,6-trimethylbenzoyldiphenylphosphine oxide, 2,6-dimethoxybenzoyldiphenylphosphine oxide, and 2,6-dichloro. Benzoyldiphenylphosphine oxide, 2,4,6-trimethylbenzoylmethoxyphenylphosphine oxide, 2,4,6-trimethylbenzoylethoxyphenylphosphine oxide, 2,3,5,6-tetramethylbenzoyldiphenylphosphine oxide, benzoyldi- (2) , 6-Dimethylphenyl) phosphonate and the like.

The photopolymerization initiator can be used alone or in combination of two or more.

Among the photopolymerization initiators, an acylphosphine oxide compound is preferable, and phenylbis (2,4,6-trimethylbenzoyl) phosphine oxide (BAPO) is more preferable.

The addition ratio of the photopolymerization initiator is, for example, 0.1 part by mass or more, preferably 0.5 part by mass or more, for example, 5.0, based on 100 parts by mass of the total of the liquid material 20 and the inorganic nanoparticles 23. It is less than or equal to parts by mass, preferably less than or less than 2.0 parts by mass.

(3) Step of Preparing Particle Dispersion Then, as shown in FIG. 2B, the inorganic particle dispersion liquid 26 is irradiated with light to photopolymerize the monomer components, and the inorganic nanoparticles 23 are dispersed in the polymer matrix 25. The particle dispersion 24 is prepared. At this time, the particle dispersion 24 is formed into a desired shape.

In order to form the particle dispersion 24 into a desired shape, for example, after injecting the inorganic particle dispersion liquid 26 into a predetermined mold, a monomer component (hydroxyl hydroxyl-containing photopolymerizable monomer and polyoxyalkylene) is used by a known light irradiation device. The inorganic particle dispersion 26 is irradiated with light (for example, ultraviolet light, visible light, etc.) until the photopolymerization of the group-containing photopolymerizable monomer) is completed.

As a result, the particle dispersion 24 having a desired shape is prepared. In FIG. 2B, the particle dispersion 24 has a crown shape for convenience, but the desired shape is not particularly limited.

The particle dispersion 24 includes a polymer matrix 25, inorganic nanoparticles 23, and alcohols 27.

The polymer matrix 25 is a photopolymer of a monomer component (a hydroxyl group-containing photopolymerizable monomer and a polyoxyalkylene group-containing photopolymerizable monomer). The polymer matrix 25 has a desired outer shape. The polymer matrix 25 has a gap 25A inside it.

The inorganic nanoparticles 23 are dispersed in the polymer matrix 25.

Such a particle dispersion 24 can also be prepared by a three-dimensional modeling apparatus (for example, a 3D printer) by a stereolithography method (for example, a laser method or the like).

(4) Step of removing alcohols from the particle dispersion Next, as shown in FIG. 2C, alcohols 27 are removed from the particle dispersion 24. Specifically, the particle dispersion 24 is heated and dried.

The drying temperature of the particle dispersion 24 is not particularly limited as long as the alcohols 27 can be removed, and is, for example, 20 ° C. or higher, preferably 60 ° C. or higher, for example, 150 ° C. or lower, preferably 100 ° C. or lower. The drying time of the particle dispersion 24 is, for example, 7 hours or more, preferably 12 hours or more, for example, 168 hours or less, preferably 36 hours or less.

As a result, the alcohols 27 are removed from the gap 25A of the polymer matrix 25. The step of removing alcohols from the particle dispersion may be carried out under atmospheric pressure or under reduced pressure.

(5) Step of firing the particle dispersion to form an inorganic substance Next, the particle dispersion 24 is fired in the air, for example, to form an inorganic substance 2 having communication holes 22. The inorganic substance 2 has the same desired shape as the particle dispersion 24.

The firing conditions for the particle dispersion 24 are, for example, milder than the conditions under which the inorganic substance 2 becomes a dense inorganic substance 2 having no communication holes 22. Under such relaxed firing conditions, the average pore diameter of the communication holes 22 of the inorganic substance 2 is adjusted to the range described later.

Specifically, the firing temperature of the particle dispersion 24 is, for example, 200 ° C. or higher, preferably 600 ° C. or higher, more preferably 1000 ° C. or higher, still more preferably 1100 ° C. or higher, for example, 1700 ° C. or lower. Is 1200 ° C. or lower. The firing time of the particle dispersion 24 is, for example, 1 hour or more, preferably 2 hours or more, more preferably 3 hours or more, still more preferably 4 hours or more, for example, 20 hours or less, preferably 15 hours or less. Is.

The firing of the particle dispersion 24 may be carried out only once under the above conditions, or may be carried out a plurality of times. For example, when firing the particle dispersion 24 three times, the primary firing is performed at 200 ° C. or higher and 400 ° C. or lower, the secondary firing is performed at 500 ° C. or higher and 700 ° C. or lower, and the tertiary firing is performed at 900 ° C. or higher and 1200 ° C. or lower.

As a result, the polymer matrix 25 is burned, and the plurality of inorganic nanoparticles 23 are sintered against each other by firing to prepare an inorganic substance 2 (inorganic sintered body) having communication holes 22.

Such an inorganic substance 2 is a sintered body in which a plurality of inorganic nanoparticles 23 are bonded to each other by firing. The inorganic substance 2 is a porous body having a monolithic structure, and includes a skeleton 21 that is continuous in a three-dimensional network and a communication hole 22 that is partitioned by the skeleton 21.

The skeleton 21 is formed from the above-mentioned inorganic material. The crystalline state of the inorganic material in the skeleton 21 may be any of a single crystal body, a polycrystalline body and an amorphous body, and is preferably a polycrystalline body or an amorphous body.

The skeleton 21 of the inorganic substance 2 is more preferably made of an amorphous body of a non-metal material, further preferably made of an amorphous body of a metal oxide, and particularly preferably an amorphous body of silica (silica glass). ) Consists of.

The communication hole 22 is a space portion of the inorganic substance 2 other than the skeleton 21. The communication holes 22 are formed by communicating a plurality of pores with each other in a three-dimensional network, and spread over the entire inorganic substance 2. Further, the communication hole 22 is opened on the surface of the inorganic substance 2 so as to communicate with the external space of the inorganic substance 2.

Further, the communication hole 22 has a hole diameter on the nano-order. The hole diameter is the diameter of the cross section in the direction orthogonal to the extending direction of the communication hole 22. The range of the pore diameter (pore distribution) of the communication hole 22 is, for example, 0.5 nm or more, preferably 1 nm or more, for example, 300 nm or less, preferably 200 nm or less, and more preferably 150 nm or less.

The average pore diameter of the communication holes 22 is, for example, 1 nm or more, preferably 5 nm or more, more preferably 10 nm or more, for example, 100 nm or less, preferably 50 nm or less, more preferably 30 nm or less, still more preferably 20 nm or less. Is. The pore distribution and average pore diameter of the communication holes 22 can be calculated by analyzing the measurement results of the nitrogen gas adsorption method by the BJH (Barrett-Joiner-Halenda) method.

Also, the volume of the communicating hole 22 in the inorganic 2, per unit mass of the inorganic 2, for example, 0.01 cm ³ / g or more, preferably, 0.03 cm ³ / g or more, more preferably, 0.05 cm ³ / g As mentioned above, for example, it is 1.00 cm ³ / g or less, preferably 0.40 cm ³ / g or less, and more preferably 0.20 cm ³ / g or less. The volume of the communication hole 22 can be calculated by analyzing the measurement result of the nitrogen gas adsorption method by the BJH method.

The specific surface area of the inorganic substance 2 is, for example, 0.1 m ² / g or more, preferably 1 m ² / g or more, more preferably 10 m ² / g or more, 100 m ² / g or less, per unit mass of the inorganic substance 2. , Preferably 50 m ² / g or less. The specific surface area of the inorganic substance 2 can be calculated by analyzing the measurement result of the nitrogen gas adsorption method by the BET method.

The inorganic substance 2 preferably has only communication holes 22 as pores, and does not have closed pores isolated in the skeleton 21 without communicating with the outside. Further, even if the inorganic substance 2 has closed pores, the volume ratio of the closed pores is 50% or less with respect to the total volume of the communicating holes 22 and the closed pores. The communication rate of the inorganic substance 2 is, for example, 50% or more, preferably 90% or more.

(6) Step of Filling the Communication Hole with the Organic Polymer Next, as shown in FIG. 2D, the communication hole 22 of the inorganic substance 2 is filled with the organic polymer 3.

To fill the communication hole 22 with the organic polymer 3, for example, the raw material monomer 31 of the organic polymer 3 is introduced into the communication hole 22, and then the raw material monomer 31 introduced into the communication hole 22 is polymerized to form the organic polymer. 3 is formed (see FIG. 1).

Further, prior to the introduction of the raw material monomer 31 into the communication hole 22, the surface of the inorganic substance 2 (inner surface of the communication hole 22) is preferably subjected to a silane coupling treatment.

For example, a solution in which a silane coupling agent is dissolved in a solvent is prepared, and the inorganic substance 2 is immersed in the solution of the silane coupling agent. At this time, an acid may be added in order to promote the hydrolysis of the silane coupling agent. Acids include, for example, inorganic and organic acids. Alternatively, a silane coupling agent and an acid may be mixed in advance to prepare a hydrolyzed aqueous solution of the silane coupling agent, and a solution obtained by dissolving the silane coupling agent in a solvent may be used.

Examples of the silane coupling agent include a methacryloxy-based silane coupling agent (for example, γ-methacryloxypropyltrimethoxysilane, 8-methacryloxyoctyltrimethoxysilane, etc.), and an amine-based silane coupling agent (for example, γ-aminopropyl). Triethoxysilane, etc.) and the like.

The silane coupling agent can be used alone or in combination of two or more.

Among the silane coupling agents, a methacryloxy-based silane coupling agent is preferable, and γ-methacryloxypropyltrimethoxysilane (γ-MPTS) is more preferable.

The solvent is not particularly limited as long as it can dissolve the silane coupling agent. Examples of the solvent include the above-mentioned aliphatic alcohols, preferably linear aliphatic alcohols, and more preferably ethanol.

The concentration of the solution of the silane coupling agent is, for example, 1.0% by mass or more, preferably 3.0% by mass or more, for example, 10.0% by mass or less, preferably 8.0% by mass or less.

The immersion temperature of the inorganic substance 2 is, for example, 10 ° C. or higher and 40 ° C. or lower. The immersion time of the inorganic substance 2 is, for example, 10 minutes or more and 24 hours or less.

After that, the inorganic substance 2 is dried as needed. As a result, the inorganic substance 2 is subjected to a silane coupling treatment. After that, the raw material monomer 31 is introduced into the communication hole 22.

The raw material monomer 31 is not particularly limited, and examples thereof include known polymerizable monomers used for medical materials. Examples of the raw material monomer 31 include a photopolymerizable monomer, and preferably a photopolymerizable monomer having an ethylenically unsaturated double bond.

Examples of the photopolymerizable monomer include α, β-unsaturated carboxylic acid, aromatic vinyl, (meth) acrylamide, (meth) acrylate and the like.

Examples of α and β-unsaturated carboxylic acids include acrylic acid, methacrylic acid, α-halogenated acrylic acid, crotonic acid, cinnamic acid, sorbic acid, maleic acid, and itaconic acid. Examples of aromatic vinyl include styrene. Examples of (meth) acrylamide include acrylamide and methacrylamide.

As the (meth) acrylate, for example, a monofunctional (meth) acrylate having one (meth) acryloyl group, a bifunctional (meth) acrylate having two (meth) acryloyl groups, and three having three (meth) acryloyl groups. Examples include functional (meth) acrylate. The (meth) acrylate includes methacrylate and / or acrylate.

As the monofunctional (meth) acrylate, for example, alkyl mono (meth) acrylate (for example, methyl (meth) acrylate, ethyl (meth) acrylate, butyl (meth) acrylate, isobutyl (meth) acrylate, octyl (meth) acrylate, 2 -Ethylhexyl (meth) acrylate, lauryl (meth) acrylate, etc.), aryl mono (meth) acrylate (eg, benzyl (meth) acrylate, etc.), amino group-containing mono (meth) acrylate (eg, 2- (N, N-) (Dimethylamino) ethyl (meth) acrylate, etc.), alkyl halide-containing mono (meth) acrylate (eg, 2,3-dibromopropyl (meth) acrylate, etc.), quaternary ammonium base-containing mono (meth) acrylate (eg, (eg, Meta) Acryloyloxide decylpyridinium bromide, (Meta) Acryloyloxide decylpyridinium chloride, (Meta) Acryloyloxyhexadecylpyridinium chloride, (Meta) Acryloyloxydecylammonium chloride, etc.), Carboxy group-containing mono (meth) acrylate (eg, 2) − Methacryloyloxyethyl phthalic acid, 2-methacryloyloxypropylphthalic acid, etc.), phosphate group-containing mono (meth) acrylate (for example, EO-modified phosphoric acid mono (meth) acrylate, etc.), the above-mentioned hydroxyl group-containing mono (meth) acrylate. And so on.

As the bifunctional (meth) acrylate, for example, alkylene di (meth) acrylate (for example, ethylene glycol di (meth) acrylate, propylene glycol di (meth) acrylate, butanediol di (meth) acrylate, neopentyl glycol di (meth)) Acrylate, 1,6-hexanediol di (meth) acrylate, 1,10-decanediol di (meth) acrylate, etc.), the above-mentioned polyethylene group-containing di (meth) acrylate, aromatic ring-containing di (meth) acrylate (for example, Bisphenol A di (meth) acrylate acrylate, Bisphenol A diglycidyl (meth) acrylate (2,2-bis [4- [3- (meth) acryloyloxy-2-hydroxypropoxy] phenyl] propane), 2,2-bis [4- (Meta) acryloyloxyethoxyphenyl] propane, etc.), urethane dimethacrylate (for example, [2,2,4-trimethylhexamethylenebis (2-carbamoyloxyethyl)] dimethacrylate, etc.), phosphate group-containing dimethacrylate, etc. (Meta) acrylates (eg, EO-modified di (meth) acrylates), phosphate ester-containing di (meth) acrylates (eg, bis (eg, 2- (meth) acryloyloxyethyl) phosphates, etc.), described above. Examples thereof include hydroxyl group-containing di (meth) acrylate.

Examples of the trifunctional (meth) acrylate include trimethylolpropane tri (meth) acrylate, trimethylolethanetri (meth) acrylate, and tetramethylolmethanetri (meth) acrylate.

The raw material monomer 31 can be used alone or in combination of two or more.

Among the raw material monomers 31, (meth) acrylate is preferably mentioned, monofunctional (meth) acrylate is more preferably mentioned, and alkyl mono (meth) acrylate is more preferably mentioned, and particularly preferably, alkyl mono (meth) acrylate is mentioned. Methyl (meth) acrylate can be mentioned.

The viscosity (@ 25 ° C.) of the raw material monomer 31 is, for example, 0.1 cP or more, for example, 40,000 cP or less, preferably 15,000 cP or less. The viscosity of the raw material monomer 31 can be measured with an E-type viscometer.

Further, a polymerization initiator is added to the raw material monomer 31 as needed.

Examples of the polymerization initiator include the above-mentioned photopolymerization initiator and organic peroxides (for example, benzoyl peroxide, cumene hydroperoxide, etc.), and preferably organic peroxides. The polymerization initiator can be used alone or in combination of two or more. The addition ratio of the polymerization initiator is, for example, 0.1 part by mass or more and 20 parts by mass or less with respect to 100 parts by mass of the raw material monomer.

Then, in order to introduce the raw material monomer 31 into the communication hole 22, for example, the inorganic substance 2 is immersed in the raw material monomer 31.

The immersion pressure is, for example, 10 kPa or more, preferably 50 kPa or more, for example, 10,000 kPa or less, preferably 1,000 kPa or less, and more preferably atmospheric pressure (101 kPa).

The immersion temperature is, for example, 1 ° C. or higher, preferably 10 ° C. or higher, for example, 50 ° C. or lower, preferably 30 ° C. or lower, and more preferably room temperature (25 ° C.).

The immersion time is, for example, 1 hour or more, preferably 10 hours or more, for example, 50 hours or less, preferably 30 hours or less.

As a result, the raw material monomer 31 is introduced into the communication hole 22.

Next, the raw material monomer 31 introduced into the communication hole 22 is polymerized by heating, for example.

The heating temperature is, for example, 40 ° C. or higher, preferably 50 ° C. or higher, for example, 100 ° C. or lower, preferably 70 ° C. or lower. The heating time is, for example, 1 hour or more, preferably 40 hours or more, for example, 100 hours or less, preferably 60 hours or less.

As a result, as shown in FIG. 1, the organic polymer 3 is formed.

The organic polymer 3 is densely filled in the communication hole 22 so that no void is generated in the communication hole 22. The organic polymer 3 is continuous in a three-dimensional network and is intertwined with the skeleton 21 of the inorganic substance 2.

In the above, the raw material monomer is polymerized by heating, but the present invention is not limited to this, and the raw material monomer can be polymerized by light irradiation without heating, or can be polymerized by heating and light irradiation. Further, in the present embodiment, the raw material monomer is a radically polymerizable monomer, but the raw material monomer is not limited to this, and the raw material monomer may be a condensing monomer. For example, polycarboxylic acids and polyols, which are condensable monomers, can be introduced into the communication pores and then polymerized.

Further, in the present embodiment, after the raw material monomer is introduced into the communication hole, the raw material monomer is polymerized to form an organic polymer, but the present invention is not limited to this, and the organic polymer is directly introduced into the communication hole. You can also.

As described above, the communication hole 22 of the inorganic substance 2 is filled with the organic polymer 3, and the nano has a two-phase co-continuous structure of the inorganic substance 2 having the communication hole 22 and the organic polymer 3 filled in the communication hole 22. Composite resin 1 is manufactured.

Such a nanocomposite resin 1 has a hardness suitable for a prosthesis.

The Vickers hardness of the nanocomposite resin 1 is, for example, 100 Hv or more, preferably 200 Hv or more, for example, 800 Hv or less, preferably 650 Hv or less, more preferably 600 HV or less, and further preferably 500 Hv or less. The Vickers hardness can be measured according to the Vickers hardness test of JIS Z 2244: 2009.

The Vickers hardness of the nanocomposite resin 1 is preferably about the same as the Vickers hardness of the tooth enamel. The Vickers hardness of tooth enamel varies depending on the age of the patient and the part of the tooth, and is, for example, 200 HV or more and 500 HV or less. The Vickers hardness range of the nanocomposite resin 1 is preferably ± 50 HV with respect to the Vickers hardness of the enamel.

The density of the nano-composite resin 1, for example, 1.70 g / cm ³ or more, preferably, 1.76 g / cm ³ or more, e.g., 2.20 g / cm ³ or less, preferably, 2.20 g / cm ³ Less than, more preferably 2.00 g / cm ³ or less. The density of the nanocomposite resin 1 can be measured by the dry automatic densitometer Accupic II 1340.

<Use of nanocomposite resin>
Such a nanocomposite resin 1 can be suitably used as a prosthesis in various medical fields. Examples of the use of the nanocomposite resin 1 include medical artificial bones, bone restoration agents, dental materials, medical teaching materials, and the like, preferably dental materials (inorganic-organic composite dental materials), and more preferably. , CAD / CAM dental restoration materials.

<Effect>
As shown in FIGS. 2A to 2D, in the method for producing the nanocomposite resin 1 described above, first, a monomer component (hydroxyl hydroxyl group-containing photopolymerizable monomer and polyoxyalkylene group-containing photopolymerizable monomer) and alcohols are contained. The inorganic particle dispersion liquid 26 is prepared by dispersing the inorganic nanoparticles 23 in the liquid material 20 to be used. Then, the monomer component of the inorganic particle dispersion liquid 26 is photopolymerized to form the particle dispersion 24.

However, when the liquid material 20 does not contain the hydroxyl group-containing photopolymerizable monomer, the viscosity of the inorganic particle dispersion liquid 26 may be excessively increased, and the particle dispersion 24 may not be formed into a desired shape by the above-mentioned forming method. be.

On the other hand, in the above method, since the liquid material 20 contains the hydroxyl group-containing photopolymerizable monomer, the viscosity of the inorganic particle dispersion liquid 26 can be adjusted within a suitable range, and the particles from the inorganic particle dispersion liquid 26 can be adjusted by the above-mentioned forming method. The dispersion 24 can be stably formed into a desired shape.

Then, after removing the alcohols 27 from the particle dispersion 24 having a desired shape, the particle dispersion 24 is fired to form the inorganic substance 2 having the communication holes 22.

However, when the liquid material 20 described above does not contain a polyoxyalkylene group-containing photopolymerizable monomer or alcohols, when the particle dispersion 24 is fired to form the inorganic substance 2, the inorganic substance 2 is poorly formed (for example, cracks). Etc.) may occur, and the inorganic substance 2 may not be maintained in a desired shape.

On the other hand, in the above method, since the liquid material 20 contains the polyoxyalkylene group-containing photopolymerizable monomer and alcohols, it is possible to suppress the occurrence of poor formation (for example, cracks) in the inorganic substance 2, and the inorganic substance 2 can be separated. It can be maintained in the same desired shape as the particle dispersion 24.

Then, the communication hole 22 of the inorganic substance 2 is filled with the organic polymer 3 to produce the nanocomposite resin 1.

As a result, the production efficiency of the nanocomposite resin 1 can be improved while the inorganic substance 2 can be molded into a desired shape.

Further, as shown in FIG. 2A, in the inorganic particle dispersion liquid 26, the dispersion ratio of the inorganic nanoparticles 23 is equal to or higher than the above lower limit. Therefore, the poor formation of the inorganic substance 2 can be stably suppressed.

Further, as shown in FIG. 2A, in the inorganic particle dispersion liquid 26, the dispersion ratio of the inorganic nanoparticles 23 is not more than the above upper limit. Therefore, when the monomer component is photopolymerized, the particle dispersion 24 can be stably formed into a desired shape, and the poor formation of the inorganic substance 2 can be suppressed more stably.

The average primary particle size of the inorganic nanoparticles 23 is at least the above lower limit. Therefore, the inorganic nanoparticles 23 can be stably dispersed in the liquid material 20, and the dispersion ratio of the inorganic nanoparticles 23 in the inorganic particle dispersion liquid 26 can be improved. Therefore, the poor formation of the inorganic substance 2 can be suppressed more stably.

Further, the inorganic nanoparticles 23 preferably have a spherical shape. Therefore, the moldability of the particle dispersion can be improved.

Further, the content ratio of the hydroxyl group-containing photopolymerizable monomer in the liquid material 20 is at least the above lower limit. Therefore, the poor formation of the inorganic substance 2 can be suppressed more stably. Further, the content ratio of the hydroxyl group-containing photopolymerizable monomer in the liquid material 20 is not more than the above upper limit. Therefore, the hardness of the nanocomposite resin 1 can be stably adjusted within a desired range.

Examples are shown below, and the present invention will be described in more detail, but the present invention is not limited thereto. Specific numerical values such as the compounding ratio (content ratio), physical property values, and parameters used in the following description are the compounding ratios (content ratio) corresponding to those described in the above-mentioned "Form for carrying out the invention". ), Physical property values, parameters, etc., can be replaced with the corresponding upper limit value (numerical value defined as "less than or equal to" or "less than") or lower limit value (numerical value defined as "greater than or equal to" or "excess"). can.

(Examples 1-3, 5-8 and 10)
2-Hydroxyethyl methacrylate (HEMA, hydroxyl group-containing photopolymerizable monomer) and triethylene glycol dimethacrylate (trade name 3G, manufactured by Shin-Nakamura Chemical Industry Co., Ltd., polyoxyalkylene group-containing light) according to the formulations shown in Table 1. A liquid material was prepared by mixing (polymerizable monomer), phenoxyethanol (POE, alcohols), and 1-propanol (PrOH, alcohols).

Next, while irradiating the liquid material with ultrasonic waves, silica particles (trade name OX50, manufactured by Nippon Aerosil Co., Ltd., average primary particle diameter 40 nm, spherical) were added in a plurality of times so as to have the formulation shown in Table 1. And mixed. Then, the ultrasonic irradiation was continued until the lumps of the silica particles disappeared, the silica particles were dispersed in the liquid material, and then the ultrasonic irradiation was stopped. Then, phenylbis (2,4,6-trimethylbenzoyl) phosphine oxide (BAPO, photopolymerization initiator) was added to the liquid material (inorganic particle dispersion) in which silica particles were dispersed so as to be as shown in Table 1. It was added and dissolved.

Next, after injecting the inorganic particle dispersion liquid containing BAPO into a columnar mold (diameter 20 mm, height 20 mm), light irradiation is performed for 15 minutes by a light irradiation device (trade name α-light V, manufactured by Morita Manufacturing Co., Ltd.). HEMA and 3G were then photopolymerized and cured.

As a result, a particle dispersion in which silica particles were dispersed was prepared in a polymer matrix of HEMA and 3G.

The moldability of the particle dispersion was evaluated according to the following criteria. The results are shown in Table 1.
〇: The cylindrical mold can be easily filled with the inorganic particle dispersion liquid.
Δ: It is difficult to fill the cylindrical mold with the inorganic particle dispersion liquid, but it can be filled by pushing it with a finger or the like.
X: It is difficult to fill the cylindrical mold even by pushing it with a finger or the like.

Then, the particle dispersion was allowed to stand at room temperature (25 ° C.) for 24 hours to dry, then heated to 80 ° C. in an oven and dried for 24 hours to remove POE and PrOH from the particle dispersion. As a result, the entire particle dispersion became cloudy.

Then, the dried particle dispersion was calcined. Specifically, the particle dispersion was placed in the firing furnace, and the temperature inside the firing furnace was raised from room temperature (25 ° C.) to 220 ° C. at a heating rate of 100 ° C./h, and then maintained for 4 hours. Then, the temperature was further raised to 600 ° C. and maintained for 3 hours, and then the temperature was further raised to 1150 ° C. and maintained for 3 hours.

As a result, the polymer matrix was burned and a plurality of silica particles were bonded to each other to obtain silica glass (porous silica) having communication holes. Then, the temperature inside the calcination furnace was lowered to room temperature (25 ° C.), and the porous silica was taken out from the calcination furnace.

The state of the porous silica was evaluated according to the following criteria. The results are shown in Table 1.
◯: No cracks (poor formation) have occurred in the porous silica, and the porous silica can maintain a desired shape similar to that of the particle dispersion.
Δ: Although cracks (poor formation) have occurred in a part of the porous silica, the porous silica can maintain the same shape as the particle dispersion.
X: A large number of cracks (poor formation) occur in the porous silica, and the porous silica cannot maintain the same shape as the particle dispersion.

Then, the porous silica was immersed in an ethanol solution of 5% by mass of γ-methacryloxypropyltrimethoxysilane (γ-MPTS) at room temperature (25 ° C.) for 3 hours. Then, the porous silica was taken out from the ethanol solution of γ-MPTS and dried at 80 ° C. for 3 hours. As a result, the surface of the porous silica was subjected to a silane coupling treatment.

Next, 10 g of methyl methacrylate (MMA, a raw material monomer) was prepared, and 0.05 g of benzoyl peroxide (BPO, a polymerization initiator) was dissolved in the MMA.

The porous silica was then immersed in MMA in which BPO was dissolved at room temperature (25 ° C.) for 12 hours under atmospheric pressure. This introduced MMA into the communication holes of the porous silica.

Then, the porous silica into which MMA was introduced was heated to 60 ° C. and held for 48 hours. As a result, MMA was polymerized to form polymethylmethacrylate (PMMA, organic polymer).

As described above, a nanocomposite resin having a two-phase co-continuous structure of porous silica (a sintered body of silica glass having communication holes) and PMMA filled in the communication holes was produced.

(Example 4)
Except for changing the silica particles (trade name OX50, manufactured by Nippon Aerosil Co., Ltd., average primary particle diameter 40 nm, spherical) to silica particles (trade name Aerosil 200, manufactured by Nippon Aerosil Co., Ltd., average primary particle diameter 12 nm, spherical). A nanocomposite resin was produced in the same manner as in Example 1. In Example 4, the silica particles were not dispersed unless they were 40 parts by mass or less with respect to 40 parts by mass of the liquid material. Therefore, the addition ratio of silica particles was set to 40 parts by mass. Further, in the same manner as described above, the moldability of the particle dispersion and the state of the porous silica were evaluated. The results are shown in Table 1.

(Example 9)
A nanocomposite resin was produced in the same manner as in Example 1 except that PrOH was not used. In Example 9, the silica particles were not dispersed unless they were 50 parts by mass or less with respect to 40 parts by mass of the liquid material. Therefore, the addition ratio of silica particles was set to 50 parts by mass. Further, in the same manner as described above, the moldability of the particle dispersion and the state of the porous silica were evaluated. The results are shown in Table 1.

(Comparative Example 1)
An inorganic particle dispersion containing BAPO was prepared in the same manner as in Example 1 except that HEMA was not used. In Comparative Example 1, the inorganic particle dispersion liquid containing BAPO could not be injected into the mold, and the particle dispersion could not be molded (moldability: ×).

(Comparative Example 2)
Porous silica was produced in the same manner as in Example 1 except that 3G was not used. In Comparative Example 2, a large number of cracks (poor formation) occurred in the porous silica, and the porous silica could not maintain the same shape as the particle dispersion (state: ×).

(Comparative Example 3)
Porous silica was produced in the same manner as in Example 1 except that POE and PrOH were not used. In Comparative Example 3, a large number of cracks (poor formation) occurred in the porous silica, and the porous silica could not maintain the same shape as the particle dispersion (state: ×).

<Evaluation>
<< Vickers hardness >>
The Vickers hardness (Hv) of the nanocomposite resin of each example and each comparative example was measured according to JIS Z 2244: 2009. Then, the Vickers hardness of each nanocomposite resin was evaluated according to the following criteria. The results are shown in Table 1.
〇: Vickers hardness (Hv) is 200 or more and 500 or less,
Δ: Vickers hardness (Hv) is 100 or more and less than 200, or Vickers hardness (Hv) is more than 500 and 800 or less.
X: Vickers hardness (Hv) is less than 100, or Vickers hardness (Hv) exceeds 800.

1 Nanocomposite resin 2 Inorganic 3 Organic polymer 20 Liquid material 22 Communication hole 23 Inorganic nanoparticles 24 Particle dispersion 25 Polymer matrix

Claims (6)

A method for producing an inorganic-organic composite medical material having a two-phase co-continuous structure of an inorganic substance having a communication hole and an organic polymer filled in the communication hole.
A step of preparing a liquid material containing a hydroxyl group-containing photopolymerizable monomer, a polyoxyalkylene group-containing photopolymerizable monomer, and alcohols.
The step of dispersing inorganic nanoparticles in the liquid material and
The hydroxyl group-containing photopolymerizable monomer and the polyoxyalkylene group-containing photopolymerizable monomer are photopolymerized to form a polymer matrix of the hydroxyl group-containing photopolymerizable monomer and the polyoxyalkylene group-containing photopolymerizable monomer. The process of preparing a particle dispersion in which inorganic nanoparticles are dispersed, and
The step of removing the alcohols from the particle dispersion and
A step of calcining the particle dispersion from which the alcohols have been removed to form an inorganic substance having communication holes, and
A method for producing an inorganic-organic composite medical material, which comprises a step of filling the communication holes of the inorganic substance with an organic polymer. The claim is characterized in that, in the step of dispersing the inorganic nanoparticles in the liquid material, the dispersion ratio of the inorganic nanoparticles is 20% by mass or more with respect to the total of the liquid material and the inorganic nanoparticles. The method for producing an inorganic-organic composite medical material according to 1. The claim is characterized in that, in the step of dispersing the inorganic nanoparticles in the liquid material, the dispersion ratio of the inorganic nanoparticles is 60% by mass or less with respect to the total of the liquid material and the inorganic nanoparticles. The method for producing an inorganic-organic composite medical material according to 1 or 2. The method for producing an inorganic-organic composite medical material according to any one of claims 1 to 3, wherein the average primary particle size of the inorganic nanoparticles is 40 nm or more. The method for producing an inorganic-organic composite medical material according to any one of claims 1 to 4, wherein the inorganic nanoparticles have a spherical shape. The content ratio of the hydroxyl group-containing photopolymerizable monomer in the liquid material is 75% by mass or more and 98% by mass or less with respect to the total of the hydroxyl group-containing photopolymerizable monomer and the polyoxyalkylene group-containing photopolymerizable monomer. The method for producing an inorganic-organic composite medical material according to any one of claims 1 to 5, wherein the method for producing an inorganic-organic composite medical material.

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