JPS6289701A - composite material - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention provides a novel spherical material whose main components are silica and a metal oxide of group Ⅰ of the periodic table (hereinafter abbreviated as group Ⅲ). and a polymerizable vinyl monomer.

[Problems to be solved by conventional technology and invention]

Conventionally, inorganic oxides whose main constituents are silica and group (I) metal oxides have been known, but their shapes are amorphous, and spherical ones are not known. Also,
A known manufacturing method is to mix silica and a Group I metal oxide, melt the mixture at a high temperature above the melting point to obtain a glassy material, and then crush the glassy material. As a result, the shape is not only irregular as described above, but also the particle size distribution is extremely wide, so that it can only be used for limited purposes. Another manufacturing method is to mix an alkoxysilane and an alcoholade of group (III) metal, hydrolyze this to obtain an agar-like gel, and then sinter the agar-like substance to produce silica and group It is known that metal oxides can be obtained. This method is superior to the above-mentioned methods in that the agar-like gel can be changed into a limited shape by forming it into a plate or a fiber. However, even if such a production method is employed, it has not been possible to obtain an inorganic oxide having a spherical shape, particularly a small particle size, for example, a uniform particle size of 0.1 to 1.0 μm.

Therefore, it has been a major technical challenge to obtain an inorganic oxide consisting of silica and a Group I metal oxide with spherical particle sizes of uniform size.

On the other hand, an object of the present invention is to obtain a composite material that provides a cured product not only in mechanical strength and surface hardness of 9, but also in transparency and surface smoothness.

[Means for solving problems]

The present inventors have succeeded in developing an inorganic oxide consisting of the above-mentioned spherical silica having a uniform particle size and a Group Ⅰ metal oxide. The inventors have also discovered that a composite material composed of the inorganic oxide and a polymerizable vinyl monomer becomes a cured product exhibiting the excellent properties described above, and has completed the present invention.

That is, the present invention consists of a spherical inorganic oxide (hereinafter simply referred to as a spherical inorganic oxide) whose main constituents are a polymerizable vinyl monomer, silica, and an oxide of a metal of Group I of the periodic table. It is a composite material characterized by the following.

In the present invention, the spherical inorganic oxide is composed of a silicon atom of silica and an ilV group metal oxide, such as titanium oxide, zirconium oxide, norphnium oxide, tin oxide, lead oxide, etc., bonded through oxygen, and mainly silica and Group Ⅰ metal oxide; its constituent components. Therefore, the composition ratio of the metal oxide of the above group (III) (hereinafter simply expressed by the general formula M02 (where M is a metal of group (III)) has a large influence on the shape of the obtained spherical inorganic oxide. Give me. Of course, the type of M02 and the manufacturing method! The influence of the composition ratio on the shape varies depending on J3 manufacturing conditions, etc., but in general, when trying to obtain a spherical inorganic oxide, it is best to keep the composition ratio of Mn2 below 30 mol%, and even below 20 mol%. Preferably Mn2, especially in the range 0#01 to 15 mol%
When selecting the composition ratio, the particles will be close to perfect spheres with uniform particle diameters. The composition ratio of MO2 can be confirmed by chemical analysis, but depending on the type of Mn2, it may also be confirmed by fluorescent X-ray analysis. However, it is usually not much different from what is calculated theoretically from the raw material ratio, so if the manufacturing raw material ratio is clear, it can also be calculated from the raw material ratio.

In such a spherical inorganic oxide, the constituent components of silica and Mn2 generally exist chemically bonded, and these constituent components cannot be physically separated. Further, whether the two components are chemically bonded can usually be confirmed by measuring the infrared spectrum and refractive index of the inorganic oxide. For example, for the infrared spectrum, Mn2 is TlO
2, an I￥f absorption can be observed at 950(-rn-', and the refractive index of the spherical inorganic oxide is between the refractive index of each of its constituent components, and the Mn2 component, for example, T
iO2.

This can be confirmed from the fact that as ZrO2 increases, the refractive index becomes higher than that of silica alone.

In the present invention, the shape, particle size, particle size distribution, etc. of the spherical inorganic oxide can be measured by taking scanning or transmission electron micrographs. Generally, the inorganic oxide of the present invention has a small particle size, for example, in the range of 0.01 to 1.0 μm, and its size distribution is extremely uniform. For example, the standard deviation value of particle diameter is 1.
It is also possible to set it to 30 or less.

According to the present invention, spherical inorganic oxides containing silica and Mn2 as main constituents have a specific surface area of 100 m''/Ji' or more, generally in the range of 100 to 200-/I; It is less than 100 m'/I, generally in the range of 1 to 50 I/9.As will be described in detail later, it is a spherical inorganic oxide obtained by reacting and hydrolyzing the raw materials of both components in an alkaline solvent. Generally, the specific surface area is 10On?
/1 or more. 50% of such inorganic oxide
If it is fired at a temperature of 0℃ or higher, generally about 500 to 1300℃, the specific surface area of the inorganic oxide becomes smaller.
r3rr? It becomes less than /f/. However, all spherical inorganic oxides have the same composition ratio and spherical shape.

In the present invention, the spherical inorganic oxide is mostly amorphous or a mixture of amorphous and partially crystalline, but 1M0
Depending on the type of the two, they may be produced as a crystalline mixture.

Generally, these determinations can be confirmed by analysis using means such as X@diffraction or refractive index measurement.

Further, the spherical inorganic oxide used in the present invention has 10H groups bonded to its surface, and the amount of the OH groups can be confirmed by measurement using an alkali neutralization method. Generally, the specific surface area is large, that is, the one before firing is 1-0 to 2-Ommol.
/g, and those with a small specific surface area, that is, those after firing, often have OH groups in the range of 0.01 to n, 10 amol/.9.

Furthermore, in the present invention, the specific gravity and refractive index of the spherical inorganic oxide are different depending on the type and composition ratio of MO2, so it is not possible to partially display them. Most commonly, the specific gravity is 1.20-6.00 and the refractive index is 1.35-1.
Many are in the 70 range.

In the present invention, the method for producing the spherical inorganic oxide is not particularly limited as long as it provides the above properties. The most typical method will be explained in detail below.

(1) A mixed solution containing a hydrolyzable low condensate of an organosilicon compound and a hydrolyzable organic compound of a group (III) metal is mixed with a mixed solution containing a low condensate of a hydrolyzable organosilicon compound and an organic compound of a group There is a method in which the reaction product is added to an alkaline solvent in which the reaction product is dissolved but not substantially dissolved therein, hydrolysis is performed, and the reaction product is precipitated.

There are various low condensates of the above-mentioned hydrolyzable organosilicon compounds, and examples of the ones that are industrially easily available include the general formula S
A low condensate obtained by partially hydrolyzing an alkoxysilane represented by i (OR) 4 is used without particular limitation. R in the general formula is an alkyl group, and lower alkyl groups such as methyl, ethyl, inpropyl and butyl are preferably used. These low condensates of alkoxysilanes may be obtained by partially hydrolyzing alkoxysilanes, or commercially available products may be used as they are or after being purified by distillation.

Further, another raw material, a hydrolyzable organic compound of Group Ⅰ metal, is represented by the general formula M(OR')a (where R' is an alkyl group). A metal alkoxide compound or a compound in which one or two alkoxide groups (OR') in the above general formula is substituted with a carboxyl group or a β-dicarbonyl group is preferred. Here, M is a group Ⅰ metal, specifically, for example, titanium or zirconium.

Germanium, hafnium, tin or lead are preferably used. Specific examples of the above-mentioned compounds that are generally preferably used in the present invention include Tl(○-1so(4H7)4
．． Ti(0-nc4H7)4゜Ti(0-CH2CH
(C2H5)C4H9)4, Ti(0-CI7H5
5) 4゜Ti(0-i,5oC5H7)2[C0(CH
s) CHCOCH5]2°Tl (0-nc4H9)2
[1”) C2H4N (C2H40H) 2 ] 2
.

Ti(O)()2[QCH(OH5)COOH)2
.

Ti(OCR2CH(C2H5)CHrOH)(4H7
)4゜Ti(0-nc4H9)2(OCOC17H55
) and Zr instead of the above T1.

These include organometallic compounds substituted with Ge, Hf a Sn, and pb.

In the present invention, the alkoxysilane low condensate and the organometallic compound are mixed in advance to prepare a mixed solution. The solvent for the above mixed solution is not particularly limited and can be used as long as it dissolves the raw materials, but methanol,
Alcohol solvents such as ethanol, impropatol, butanol, ethylene glycol, and propylene gellicol are preferably used. Further, organic solvents such as ether solvents such as dioxane and diethyl ether, and ester solvents such as ethyl acetate may be used by partially mixing them with the above alcoholic solvent. In addition, although it is common to dissolve each of the raw materials separately in a solvent and then mix the solvents, it is also possible to add and dissolve one raw material in the solvent to form a mixed solution. I can do it. Furthermore, it is generally preferable for the concentration of the solution in which the raw materials are dissolved to be low, but if it is too low, the amount of solvent used will increase significantly, and if the concentration is too high, it will be difficult to control the reaction and it will be inconvenient to handle. Taking these into consideration, if appropriate decisions are made, the raw material e
Most preferably, it is used at a concentration of less than 50% by weight, preferably in the range of 5 to 50% by weight.

In order to obtain the spherical inorganic oxide used in the present invention, silicon (Sl) and group
) and the amount of water used for partial hydrolysis of the hydrolyzable organosilicon compound.

For example, water in a solution containing a hydrolyzable organosilicon compound is contained in the solvent, or is actively added to hydrolyze the raw material organosilicon compound, but the amount of water If there is too much, it is generally difficult to make the inorganic oxide spherical, and the shape of the obtained inorganic oxide tends to be amorphous. Therefore, in order to obtain a spherical inorganic oxide, the amount of water in the solution containing the hydrolyzable organosilicon compound should be selected to be as small as possible.

It is also preferable to control the mixing ratio of 81 and M as well as the amount of water added to the solution containing the hydrolyzable organosilicon compound. 1″-preferred.

It is currently unclear how the above conditions affect the formation of spherical inorganic oxides, but it is believed that an alkoxysilane oligomer must be present as an intermediate during the formation of the inorganic oxides. I'm guessing.

This phenomenon can also be inferred from the following facts. That is, for example, when tetraethylsilicate (5i(Oεt)4) is hydrolyzed by adding water, analysis means such as gas chromatography reveals that immediately after the hydrolysis, the following intermediate having a silanol group is present. You can check it with.

The above-mentioned intermediates are highly reactive and react with each other or with other ethyl silicate to form a high condensate through a dealcoholization reaction and disappear.

When the amount of the intermediate produced is appropriate, the final reaction product, the inorganic oxide, has a spherical shape. When using distilled commercially available tetraethyl silicate as a starting material, the desired intermediate can be obtained after adding a predetermined amount of water, for example, at 25°C for 2 to 3 hours, or at 60°C for several minutes to 10 minutes. However, in the case of raw materials that are difficult to hydrolyze, hydrolysis can be promoted by adding a hydrolysis promoter such as a mineral acid such as hydrochloric acid or nitric acid, or an ion exchange resin. When adding the above-mentioned hydrolysis accelerator, since the rate of hydrolysis varies depending on the amount of the hydrolysis accelerator added, it is sufficient to determine in advance reaction conditions that will allow suitable hydrolysis. Therefore, the amount of water in the solution in which the hydrolyzable organosilicon compound is dissolved, that is, the amount of water for hydrolyzing tetraethylsilicate, has a large influence on the shape of the obtained inorganic oxide, that is, whether it is spherical or not. This is clear from the above results.

The abundance ratio of M and 81 in the raw material mixture solution influences the refractive index of the obtained spherical inorganic oxide. Therefore, if it is necessary to change the refractive index, the above ratio may be controlled.

It is believed that when the raw material mixture is stirred or left to stand still, a part of the organosilicon compound is further hydrolyzed and reacts with the organic compound of the Group I metal. This is because a solution of an organosilicon compound dissolved in an alkaline solvent, which will be described later, and
A spherical inorganic oxide cannot be obtained even if a solution containing a group metal organic compound is added and reacted separately without mixing and preparing the solution in advance. Therefore, in producing the spherical inorganic oxide of the present invention, it is necessary to prepare a solution in which the same raw materials are mixed in advance. The conditions for preparing the mixed solution are not particularly limited, but it is generally preferable to prepare the mixed solution under stirring or by standing at 0 to 80° C. for several minutes to several hours in order to uniformly disperse and react the raw materials.

The raw material mixture solution prepared as above is then added to an alkaline solvent in which the raw materials are dissolved but the constituent inorganic oxides are not substantially dissolved. This is to precipitate a spherical inorganic oxide which is a constituent component. The solvent that dissolves the raw material but does not substantially dissolve the produced spherical inorganic oxide is not particularly limited, and known organic solvents may be used. The solvents that are generally preferably used are the same alcoholic solvents as those described above as the solvents for the low condensates of organosilicon compounds and the organic compounds of Group Ⅰ metals;
Alternatively, it is a water-containing solvent consisting of water and a mixed solvent obtained by adding a portion of an organic solvent such as an ether solvent or an ester solvent to the alcoholic solvent. As mentioned above, the water-containing solvent needs to be alkaline. Although known compounds can be used to make the mixture alkaline, ammonia is generally most preferably used.

Since the particle size of the spherical inorganic oxide of the present invention is influenced by factors such as the type of organic solvent, the amount of water, and the alkali concentration, it is preferable to appropriately determine these conditions in advance.

In general, the alkaline concentration of alkaline solvents is 1.0 to 10
It is preferable to select within the range of mole/L, and the higher the alkali Q 6 degree, the larger the particle size of the obtained spherical inorganic oxide tends to be. The amount of water in the alkaline solvent is required to further promote hydrolysis and produce spherical inorganic oxides, and is generally 0.5 to 50.
It is preferable to select from the range of mole/L. Generally, the higher the concentration of water is, the larger the particle size of the obtained spherical inorganic oxide tends to be. Furthermore, another factor that influences the particle size of the spherical inorganic oxide is the type of organic solvent, and generally speaking, the particle size of the obtained spherical inorganic oxide tends to increase as the number of carbon atoms increases. be.

The method of adding the raw material mixture solution to the alkaline solvent is not particularly limited, but it is generally preferable to add the raw material mixture solution in small amounts over a long period of time, and it is usually sufficient to carry out the addition in a range of several minutes to several hours. In addition, the reaction temperature varies depending on various conditions and cannot be limited to a specific temperature, but it is usually 0°C to 0°C under atmospheric pressure.
What is necessary is just to carry out at 40 degreeC, preferably about 10-30 degreeC.

The above reaction can also be carried out under reduced pressure or increased pressure, but since it proceeds satisfactorily under atmospheric pressure, it may be carried out at normal pressure.

The product precipitated by the above reaction operation may be separated and then dried. As described above, the spherical inorganic oxide thus obtained contains 7 Lika and Mn2 as main constituents, and has a specific surface area of 100 ffIs/g or more.

By selecting various materials as mentioned above, the particles are spherical and have an excellent particle size distribution with a particle size generally in the range of 0.1 to 1.0μ and a standard deviation value of particle size of 1.30 or less. It is an inorganic oxide.

(2) In method 2 of above (1), seeds made of silica polymer that serve as nuclei for precipitation are pre-existing in an alkaline solvent, and then a reaction similar to that of above (1) is carried out. There is a method for obtaining spherical inorganic oxides.

The seeds used in the above method 2 are not particularly limited and can be used as long as they are particles made of silica polymer. The method of making such seeds exist is not particularly limited, but for example, a method of dispersing particles that have already been separated into particles in an alkaline solvent, or a method of producing them in an alkaline solvent and using them as seeds without separating them is possible. Suitably adopted. To explain the latter method in more detail, seeds made of silica polymer are first generated by further hydrolyzing alkoxysilane or a low condensate thereof, and the above (1) is prepared in the presence of the silica polymer. ) to obtain spherical inorganic oxides. The alkoxysilane or its low condensate is hydrolyzed into a silica polymer in a solvent that dissolves the alkoxysilane or its low condensate but does not dissolve the silica polymer. The silica polymer serves as the core of the inorganic oxide that will eventually be produced, and it does not necessarily have to be large enough to be visible to the naked eye as a precipitate in the above solvent. The particles may be so small that they cannot be detected. Further, the method for producing a silica polymer from alkoxylan or its low condensate is not particularly limited, and any known hydrolysis method can be employed. For example, a specific amount of water as explained in (1) above may be present in the same alkaline solvent as explained in (1) above, and alkoxysilane or a low condensate thereof may be added. The alkoxysilane or its low condensate may be added as is, but generally it is dissolved in soluble G as explained in (1) above, and 1 to 5
It is preferable to adjust the concentration to 0% by weight.

After producing the silica polymer, spherical inorganic oxides may be precipitated in the same manner as in (1) above, and separated and dried.

The spherical inorganic oxide thus obtained is a spherical inorganic oxide having silica as the core and silica and Mn2 as the main components, so that the resulting particle size distribution is particularly good. Also, the specific surface area of the obtained spherical inorganic oxide is 100rr? /g
The above particles have a particle size of about 3.1 to 1.0 μm.

'3) A mixed solution containing a hydrolyzable low condensate of an organosilicon compound and a hydrolyzable organic compound of a metal of group Ⅰ of the periodic table is mixed with a low condensate of the organosilicon compound and a hydrolyzable organic compound of a metal of group Ⅰ of the periodic table. The organic compound of group metal is dissolved but the reaction product is not dissolved in an alkaline solvent to perform hydrolysis and precipitate the reaction product, and then a hydrolyzable organosilicon compound is added to the reaction system and hydrolyzed. There is a way to get it.

The method (3) above is used up to the step of precipitating a spherical inorganic oxide whose main constituents are silica and Mn2.
), but in one method, after forming a precipitate of the inorganic oxide, an organic silicon compound is added and reacted. The organosilicon compound to be reacted at the end is not particularly limited, and may be an alkoxysilane represented by the general formula 5i(OR)i (where R is an alkyl group) or a lower condensate thereof used as the raw material. The method of reacting the alkoxysilane or its low condensate with the precipitate is not particularly limited and can be carried out by any known method. For example, if a solution in which alkoxysilane or its low condensate is dissolved is added to an alkaline solvent containing the precipitate, or to a slurry solution prepared by redispersing the precipitate in an insoluble solvent after separation, and the reaction is caused. good. As the solution for dissolving the insoluble solvent for the precipitate and the alkoxysilane, the same type of solvent as the solvent used for dissolving the raw materials is preferably used.

Furthermore, in order to cause the alkoxysilane or its low condensate to react with the precipitate, the alkoxysilane needs to be hydrolyzed, so water must be present in the reaction solvent. The amount of water applied is the same as the conditions for precipitating the reaction product containing silica and M(')2 as main components in (1) above. In addition, when the solvent in which the alkoxysilane or its low condensate is dissolved is added to the solution in which the precipitate is present, the alkoxysilane 4 degree is preferably lower, and is generally 50% by weight or less, preferably 1 to 30% by weight. It is best to use it as a percentage. Further, the addition time of the alkoxysilane solution varies depending on the amount of the solvent to be added, but may generally be selected from a range of several minutes to several hours. Of course, when adding the alkoxysilane, it is also possible to directly add the alkoxysilane to the solvent in which the alkoxysilane 11 precipitate is present without dissolving it in the solvent, but this method is difficult to control the reaction industrially. It is better to avoid it if possible.

The precipitate of spherical inorganic oxide obtained by the above method may be separated and then dried. Furthermore, the above-mentioned inorganic oxide has silica and MO2 as its main constituents, and has a specific surface area of 10 (lt'/,
9 or higher. However, due to the manufacturing method, it is presumed that the particle surface layer of the inorganic oxide is covered with only silica or a layer with a high silica content, and the inside of the particle has a structure in which silica and MO2 are combined. The inorganic oxide obtained as described above has chemical properties similar to silica.

(4) In the method (3) above, seeds made of silica polymer are pre-existing in an alkaline solvent as in the method (2) above, and then the same reaction as in (3) above is carried out to form spherical particles. This is a method for obtaining inorganic oxides.

The method (4) above is a combination of the above (1), (2) and (3), and the conditions explained for these reactions can be used as they are. The inorganic oxide obtained by this method has a layer mainly composed of silica and Group I metal oxide around the silica polymer seeds, and the surface is covered with a layer mainly composed of silica. Spherical inorganic oxides are present. Further, the specific surface area of the inorganic oxide is 100ff+1/
, 9 or more, and in the case of spherical particles, the particle size is in the range of 0.1 to 1.0, and the standard deviation value of the particle size is 1.30 or less. .

The spherical inorganic oxides obtained by the above methods (1), (2), (:s) and (4) are all mainly composed of white or yellowish white amorphous powder, and are particularly spherical. Those obtained as particles are useful.

The inorganic oxide thus obtained generally has a large specific surface area of 100 m''/Ji+ or more, as described above.

In the present invention, spherical inorganic oxides obtained by calcining the products obtained by the above methods (1) to (4) to have an extremely reduced number of 10H groups on their surfaces are also suitably used. The firing method is not particularly limited and may be any known method.
It may be fired at a temperature of 300°C or higher.

By firing, the specific surface area of the spherical inorganic oxide becomes smaller, and when fired at a temperature of 500°C or higher, it becomes 100 m''/
, the specific surface area is less than 9.

Furthermore, when the spherical inorganic oxide is fired at a temperature of about 500° C. or higher, the specific surface area is often almost the same as that theoretically calculated from the particle diameter as a true sphere.

The above firing temperature may change the structure of the powder. For example, when the amorphous inorganic oxide is fired, it may remain amorphous, become amorphous with some crystalline material, or even become mixed with crystalline substances. Even.

As mentioned above, the spherical inorganic oxide used in the present invention has the most characteristic use in that it is spherical in shape. That is, when the composite material of the present invention obtained by using such an inorganic oxide together with a polymerizable vinyl monomer as a dental filler is used as a restorative material, it is possible to significantly increase the powder filling rate, and as a result, Not only can the mechanical strength and surface hardness of the molded product obtained by polymerizing the vinyl monomer be increased, but also the transparency and surface smoothness are significantly improved, which is a very useful effect in practical use.

In particular, polymerizable polymer monomers and particle sizes of 0.1 to 1.
When made into a composite material comprising the above-mentioned fired spherical particles having a particle size in the range of 0μ, it exhibits excellent properties.

One component of the composite of the present invention is a polymerizable vinyl monomer. The vinyl monomer is not particularly limited, and known ones commonly used as dental restorative materials can be used. The most typical vinyl monomer is a polymerizable vinyl monomer having an acrylic group and/or a methacrylic group. Specific examples of vinyl monomers having acrylic and/or methacrylic groups include bisphenol A diglycidyl methacrylate, methyl methacrylate, bismethacryloethoxyphenylpropane, triethylene glycol dimethacrylate, diethylene glycol dimethacrylate,
Preferred are tetramethylol triacrylate, tetramethylolmethane trimethacrylate, trimethylolethane trimethacrylate, and the like.

Also preferably used is a vinyl monomer having a urethane structure represented by the following structural formula.

C=O H Not ten' H C=O CH2=CC-0-CH2-CH-CH2-0-CC=
CH2 However, in the above formula, R, , R2, R5 and R4 are the same or different H or C) (5, and ÷A is preferable.

Since these vinyl monomers are known as materials for dental restorative materials, they may be used alone or in combination as required.

The other component constituting the composite material of the present invention is the above-mentioned spherical inorganic oxide. The inorganic oxide has a particle size of 0.1 to 1.0μ
It is preferable to use spherical particles within the range of 1.30 and the standard deviation value of the particle size distribution within 1.30.

Particle size 9 Particle shape and particle size distribution are both very important factors as long as they are used in dental composite materials. For example, if the above particle size is smaller than 0.1μ, the viscosity will increase significantly when it is kneaded with a polymerizable vinyl monomer to form a paste mixture, and it is necessary to increase the blending ratio to prevent the viscosity increase. Otherwise, the operability deteriorates, so that it cannot be used as a material for practical use. In addition, if the particle size is larger than 1.0 μ and %A, there are defects such as the abrasion resistance or surface smoothness of the resin after polymerization of monovinyl monomer is reduced, and the surface hardness is also reduced. Undesirable.

Furthermore, if the standard deviation value of the particle size distribution is larger than 1.30, the operability of the composite material decreases, so that the composite material cannot be used for practical use. Furthermore, even if the above-mentioned spherical inorganic oxide has a particle size in the range of 0.1 to 1.0μ and the standard deviation value of the particle size distribution is within 1.30, the shape of the particle is spherical. Otherwise, the wear resistance, surface smoothness, surface hardness, etc. will not be satisfactory. For example, when using the above composite material as a dental restorative material, not only is operability an important factor, but also the mechanical strength, abrasion resistance, and surface smoothness of the resulting cured composite resin must be sufficiently maintained. must be kept in good condition. Therefore, it is generally preferable to select the amount of the inorganic oxide to be added in the range of 70 to 90% by weight.

In addition, when used as the above-mentioned dental composite restorative material, a paste-like mixture consisting of the inorganic oxide, a polymerizable vinyl monomer, and a polymerization accelerator (for example, a tertiary amine compound), an inorganic oxide, a vinyl monomer, and A method is preferably used in which a paste-like mixture consisting of a polymerization initiator (for example, an organic peroxide such as benzoyl peroxide) is prepared in advance, and the two are kneaded and cured immediately before the repair operation.

〔effect〕

The composite resin obtained by curing the composite material of the present invention has mechanical strength such as compressive strength that is comparable to conventional ones, and has excellent abrasion resistance and surface smoothness, as well as high surface hardness ( It has many excellent features such as being very easy to polish the surface and improving transparency.However, the reason for these features is currently not clear, but this book The inventors are thinking as follows: First, the inorganic oxide particles are spherical in shape and the standard deviation of the particle size distribution is within 1.30. Compared to conventional fillers with a wide particle size distribution and irregular shapes, the inorganic oxide is more uniformly and densely packed into the composite resin obtained by curing. Second, by using particles with a particle size in the range of 0.1 to 1.0 μm, the particles after curing are more The polished surface of the composite resin becomes smooth, and on the other hand, the total specific surface area of the filler is smaller than when using ultrafine particles and child fillers whose main components are microscopic particles of several tens of microns. Possible reasons include the fact that a large amount of filler can be filled under conditions where

In addition to the characteristics due to the shape as described above, the filler according to the present invention can easily match the refractive index of the filler itself with that of the vinyl monomer polymer, so that by matching the refractive index, it is extremely A composite resin with excellent transparency can be obtained.

By blending the specific spherical inorganic oxide and a polymerizable vinyl monomer, the above composite material exhibits a number of previously unanticipated advantages as described above.

The above-mentioned composite material exhibits the above-mentioned advantages by blending two components, a polymerizable vinyl monomer component and a specific spherical inorganic oxide component, but in addition to these components, there is also a compound that is generally used as a dental restorative material. Additional components can also be added as needed. Typical of these additive components are as follows. For example, a colored face for matching one color of radical polymerization inhibitor.

There are UV absorbers, etc.

〔Example〕

The present invention will be described in more detail with reference to Examples below. Measurements of various properties used in the Examples below were carried out as follows, without particular mention.

(1) Refractive index A solvent having the same refractive index as the inorganic oxide of the sample was prepared, and the refractive index of the solvent was used as the refractive index of the sample. The method for preparing the solvent was to suspend the sample in the solvent and prepare the composition of the solvent at a constant temperature so that it would appear more transparent when observed with the naked eye. The solvents used were pentane, hexane, cyclohexane, toluene, styrene, methylene iodide, etc., and the refractive index of the solvent was measured with an Ape refractometer.

(2) Weigh several samples of inorganic oxides with surface OH groups by 2.00 Wg) 10
The mixture was placed in a 0- Erlenmeyer flask, 80 m of 0.05 N NaOH aqueous solution was added thereto, the flask was sealed with a rubber stopper, and the flask was left stirring for 12 hours. Thereafter, the inorganic oxide and the solution were separated using a centrifuge, and 10- was pipetted from this solution, and 0.05 N
Neutralization titration was carried out with an aqueous HCl solution. The HC2 aqueous solution required for neutralization is referred to as Aug. Note that the same operation is performed without adding the sample, and the HC1 aqueous solution required for neutralization is designated as Bd. il of surface -OH groups per unit weight of inorganic oxide
(x mmoLe/, 9) is calculated by the following formula.

(B-A)XO105X8 X= (3) Specific gravity Specific gravity was measured according to the pyranometer method.

(4) Standard deviation value of particle size and particle size distribution Take a scanning electron microscope photo of the powder, and calculate the number of electrons (n) observed within the unit field of view of the photo and the particle size (diameter It is calculated using the following formula.

However, X = -(a average diameter) (5) Specific surface areaShibata Kagaku Kiki Kogyo ■Rapid surface measuring device ff! tSA-10
00 was used. The measurement principle is the BET method.

(6) Composite paste preparation and curing method
-Amorphous silica surface-treated with methacryloxypropyltrimethoxysilane and vinyl monomer were placed in an agate mortar at a predetermined ratio and thoroughly kneaded until a uniform paste was obtained. Next, the paste was divided into three equal parts, and a polymerization accelerator was further added to one paste and thoroughly mixed (this was referred to as paste A). In addition, an organic peroxide catalyst was sufficiently mixed into the other paste (this is referred to as paste B).
. Next, equal amounts of Paste A and Paste H were kneaded for about 30 seconds, filled into a mold, and hardened.

(7) Compressive strength Paste A and paste) B were mixed and polymerized at room temperature for 30 minutes, and then immersed in water at 37° C. for 24 hours to prepare a test piece.

Its size and shape are cylindrical with a diameter of 6 degrees and a height of 121 mm. This test piece was attached to the testing machine (UTM-5T manufactured by Toyo Gate Win) L, and the crosshead speed was 10.
Compressive strength was measured at +++ m /min.

(8) Bending strength Paste A and paste B were mixed and polymerized at room temperature for 30 minutes, and then immersed in water at 37° C. for 24 hours to prepare a test piece. Its size and shape are prismatic, measuring 2 x 2 x 25 m. The bending test was carried out using a bending test fixture with a distance between fulcrums of 20 mm attached to Toyo Baudwin's UTM-5T, and a crosshead speed of 0-5 wm/min.

(9) Toothbrush wear depth and surface roughness After mixing paste A and paste B and polymerizing at room temperature for 60 minutes,
A test piece was immersed in water at 37°C for 24 hours. Its size and shape are 1.5x10x10 board-like. After abrading the test piece with a toothbrush for 1500 m under a load of 400 g, the average roughness was sufficiently determined using a surface roughness meter (Surfcom A-100). Further, the wear depth was determined by dividing the wear weight by the total composite resin density.

(10) Surface Hardness Pace) A and Pase) B were mixed and polymerized at room temperature for 30 minutes, and then immersed in water at 37° C. for 24 hours to prepare a test piece. Its size and shape are 2.5 x 10 discs. The measurement used a micropurinelle hardness test.

Furthermore, the abbreviations used in the examples are as follows unless otherwise specified.

Ct450 0C) (3Ill
Il+1111-4H; CH2
-CC-C-CH2("H("H2-0-CC-CE-T
2zekyou U (r+(2+-NH slO 彎(J(2-C-C-0-CH2CHCH2-0-C-C
-CH2C-(')N)(CH2-C-C-o-CH2C'HC'H2()-C-
C-CH2CT-1500CH5 Ill II+C-〇ξ ■〇-0 Station production example 1 5.4I water and tetraethylsilicate C5i (OC2H5) 4-manufactured by Nippon Colcoat Chemical Co., Ltd. Product name: Ethylsilicate 2812081/l-To 1.2t of methanol This solution was hydrolyzed with stirring at room temperature for about 2 hours, and then dissolved in tetrabutyl titanate (
T1(0-nC4H9)4JapanMdatsuM) 54.01
was added to a solution dissolved in 0.5 t of Improper Tool while stirring to prepare a mixed solution of tetraethyl silicate hydrolyzate and tetrabutyl titanate.

Next, a glass reaction vessel with an internal volume of 10 tons equipped with a stirrer is filled with 2.5 tons of methanol, and an ammonia aqueous solution of 5oo II (Cm degree 25 wt%) is added to this to prepare an ammoniacal methanol solution, and this solution is added to the previously prepared ammonia solution. A mixed solution of the hydrolyzate of tetraethyl silicate and tetrabutyl titanate was added over about 2 hours while maintaining the temperature of the reaction vessel at 20°C. The reaction solution became milky white within a few minutes after the addition started. After the addition was complete, stirring was continued for one hour, and the solvent was removed from the milky white reaction solution using an evaporator.
A milky white powder was obtained by further drying at 80° C. under reduced pressure.

As a result of observation using a scanning electron microscope, the shape of the powder was spherical, the particle size was in the range of 0.10 to 0.20 μm, and the standard deviation value of the particle size was 1.20. Also B
The specific surface area determined by the E', T method was 120/I.

According to X-ray analysis, a gentle mountain-shaped absorption centered around 2θ=25 was observed, and it was confirmed that the material had an amorphous structure.

Furthermore, thermal changes and weight changes were measured using a differential thermal analyzer and a thermobalance. As a result, there was an endotherm at around 100℃, which seems to be due to dehydration, and a decrease of 1.
A decrease in exothermic weight was observed at around 600°C. then 10
No thermal change or weight change was observed up to 00°C.

The specific surface area of the powder after firing at 1000℃ for 4 hours is 3
0rr? /'1. The number of surface −〇H groups is 0.08 mmo
le/# *Specific gravity is 2.30 and refractive index is 1.53~
1.54, and X-ray analysis shows a gentle mountain-shaped absorption centered at 2θ = 22° and a small absorption based on anatase-type titanium oxide, indicating that it is a mixture of amorphous and crystalline materials. Something was predicted. As a result of measuring the infrared absorption spectrum, an absorption band based on 81-〇-Ti was observed at 950cIn-', and TlO was determined by fluorescent X-ray analysis.
The content of 2 was in agreement with the calculated value from the amount of preparation, and the yield was also in agreement with the value calculated from the amount of preparation. The actual value of the TlO2 content of the powder is 15.0 mole% (the calculated value is 13.0 to
ole%), and the actual value of the powder yield was 70.0 g (calculated value was 70.8.9).

The powder obtained from the above results is anatase type TiO2
TiO213,0mo1%, 5i0 containing crab
It was confirmed that this was a spherical inorganic oxide having an amorphous structure with a composition of 287.0 mo1%.

Production Example 2 1.2 x 10-5 mole/t of aqueous hydrochloric acid solution 5.4- and a solution of 208.9 tetraethyl silicate dissolved in 1.2 t of methanol were mixed and stirred for 1 hour. Tetraptyl titanium used in
54.0! ! was added to a solution dissolved in 1.5 t of Improper Tool while stirring to prepare a mixed solution of tetraethyl silicate hydrolyzate and tetrabutyl titanate.

Next, Improper Tool 2.56 was introduced into a glass reaction vessel with an internal volume of 10/2 and equipped with a stirrer, and 500. !
An ammonia aqueous solution (concentration 25 wt%) of i+ was added to prepare an ammonia impropat tool solution. Next, a solution of 4.0 N of tetraethyl silica dissolved in 100% methanol was added to the ammoniacal impropatul solution as an organosilicon compound solution for making silica seeds over a period of about 5 minutes, and 5 minutes after completion of addition. When the post-reaction solution became slightly milky white, the above mixed solution was added over a period of about 2 hours while maintaining the temperature of the reaction vessel at 20°C. As the mixed solution was added, it became a milky white suspension. After the addition was completed, stirring was continued for 1 hour, the solvent was removed from the milky white reaction solution using an evaporator, and the mixture was further stirred for 8 hours.
A milky white powder was obtained by drying under reduced pressure at 0°C.

As a result of observation using a scanning electron micrograph, the shape of the powder was spherical, the particle size was 0.30 to CL40 μm, and the standard deviation value of the particle size was 1.12. Further, the specific surface area determined by the BET method was 110-7 g. According to X-ray analysis, a gentle mountain-shaped absorption centered around 2θ=25° was observed, and it was confirmed that the material had an amorphous structure.

Thermal changes and weight changes measured by a differential thermal analyzer and thermobalance showed similar trends to those of the powder of Example 1.

The specific surface area of the powder after firing at 1000℃ for 4 hours is 1
1rr? /1. The number of surface −〇H groups is 0.09 mmol
e/JF + specific gravity is 1.25 and refractive index is 1.5
3 to 1.54, and in X-ray analysis 2θ = 22'
A gentle chevron-shaped absorption centered on , and a small absorption thought to be based on anatase-type titanium oxide are observed.
It was confirmed that it was a mixture of amorphous and crystalline materials.

As a result of measuring the infrared absorption spectrum, 5i-
An absorption band based on 0-Ti was observed. Furthermore, the content of TlO2 determined by fluorescent X-ray analysis agreed with the calculated value from the charging amount, and the yield also agreed with the calculated value from the charging amount. Powdered TiO
The actual value of the content of 2 is 13.5 mole% (the calculated value is 13.5 mole%), and the actual value of the powder yield is 73.1.
9 (calculated value was 73.9.9).

The powder obtained from the above results is TiO215.5mol
It was confirmed that the oxide was a spherical inorganic oxide having an amorphous structure with a composition of e% and 5i02 and 86.5 mole%.

Production Example 3 5.4 g of water and the same tetraethyl silica (208II) used in Example 1 were dissolved in methanol (t2t), and this solution was hydrolyzed with stirring at room temperature for about 2 hours, and this was used in Example 1. Same as tetrabutyl titanate 5
A mixed solution of tetraethyl silicate hydrolyzate and tetrabutyl titanate was prepared by adding 0.54 Vc of 4.011t Iapropatol to a solution with stirring. Next, a glass reaction vessel with an internal volume of 10 tons equipped with a stirrer was filled with methanol and 2.51 g of methanol, and 1 csooy of an ammonia aqueous solution (Ca content: 25 wt%) was added thereto to prepare an ammoniacal methanol solution. The previously prepared mixed solution was added to this solution over about 2 hours while keeping the temperature of the reaction vessel at 20°C to precipitate the reaction product, and then a solution consisting of 0.5 t of methanol containing 104 g of tetraethyl silicate was added. was added over about 2 hours. After the addition was completed, stirring was continued for 1 hour, the solvent was removed from the milky white reaction liquid using an evaporator, and the mixture was further dried at 80° C. under reduced pressure to obtain a milky white powder.

As a result of observation using a scanning electron microscope photograph, the shape of the powder was spherical, the particle size was in the range of 0.12 to 0.22 μm, and the standard deviation value of the particle size was 1.10. According to X-ray analysis, a gentle mountain-shaped absorption centered around 2θ = 25° was observed, indicating that the material had an amorphous structure. Further, the specific surface area determined by the BET method was 110/9. Furthermore, thermal changes and weight changes were measured using a differential thermal analyzer and a thermobalance. The results showed the same tendency as in Example 1. After firing this powder at 1000°C for 4 hours, the specific surface area of the powder is 19n? /I-The number of -OH groups on the surface is 0.08 mmole/g, the specific gravity is 1.28 and the refractive index is 1.53-1.54, and the X-ray analysis shows that 2θ = 2
A gentle mountain-shaped absorption centered at 2° and a small absorption that was thought to be based on anatase-type titanium oxide were observed, confirming that the material was a mixture of an amorphous and crystalline material. As a result of measuring the infrared absorption spectrum, S
An absorption band based on i-〇-Ti was observed. Also, fluorescent X
The content of TlO2 determined by line analysis agreed with the value calculated from the amount of feed, and the yield also agreed with the value calculated from the amount of feed. The actual value of the content of 'ri02 in the powder is 9.1 mole% (the calculated value is 9.1 mole%), and the actual value of the yield of the powder is 9.
951 (calculated value is 99.9.9).

The powder obtained from the above results is TiO29.1mo1%
, consisting of a composition of 5t02 90.9 mole%,
It was confirmed that it was a spherical inorganic oxide having an amorphous structure containing a slight amount of anatase-type TiO2.

Production Example 4 5.41 liters of water and 208I of the same tetraethyl silicate used in Example 1 were dissolved in 1.2 AVc of methanol.
This solution was hydrolyzed at room temperature with stirring for about 2 hours.

Then, add 0.5 t of Improper Tool (54.0.9) to the same tetrabutyl titanium as used in Example IK.
was added to a solution of tetraethyl silicate with stirring to prepare a mixed solution of tetraethyl silicate hydrolyzate and tetrabutyl titanate. Next, 2.5 tons of methanol was introduced into a glass reaction solution with an internal volume of 10 tons equipped with a stirrer, and a 5001 ammonia aqueous solution (concentration 25 wt%) was added to prepare an ammoniacal methanol solution, and silica seeds were added to this. 4. Tetraethyl silicate as an organosilicon compound solution for making. A solution of Oy dissolved in methanol 100- was added over a period of about 5 minutes, and 5 minutes after the addition was completed, when the reaction liquid was slightly milky, the above mixed solution was added again while maintaining the temperature of the reaction vessel at 20 °C. The reaction product was added over about 2 hours to precipitate the reaction product. Then continue with Tetraethyl (1) 208. Methanol containing F1. A solution consisting of OL was added to the system in which the reaction product was precipitated over a period of about 2 hours. After the addition was completed, stirring was continued for 1 hour, the solvent was removed from the milky white reaction solution using an evaporator, and the temperature was further heated to 80°C.

A milky white powder was obtained by drying under reduced pressure.

Observation results using a scanning electron microscope B.

The shape of the powder is spherical, and its particle size is 0.615 to 0.25μ.
m range, and the standard deviation value of the particle size is 1.15
Met. According to X-ray analysis, a gentle mountain-shaped absorption centered at 2θ=25.5° was observed, indicating that the material had an amorphous structure. Also, the specific surface area according to the BET method is 120
It was I/11. Furthermore, thermal changes and weight changes were measured using a differential thermal analyzer and a thermobalance. The results showed the same tendency as in Example 1. The specific surface area of the powder after firing at 1000℃ for 4 hours is 20tt? /11. The number of surface -〇H groups is 0.08 mmole/g, and the specific gravity is 2.4.
0° and a refractive index of 1.53 to 1.54, and X-ray analysis shows a gentle mountain-shaped absorption centered at 2θ = 22° and a small absorption based on anatase-type titanium oxide, indicating that it is an amorphous material. It was confirmed that it was a mixture of Infrared absorption spectrum measurement result: 950/7F
! An absorption band based on 8i-0-Ti was observed at -'. Furthermore, the ratio of Sl and T1 determined by fluorescent X-ray analysis was consistent with the ratio of amounts used in the preparation, and the yield was also consistent with the value calculated from the amounts used in the preparation. From the above results, TiO27.3m01%, 5i0292.7r, containing a small amount of anatase-type TlO2.
It was confirmed from the composition of nole% that it was a spherical inorganic oxide with an amorphous structure.

Example 1 A spherical inorganic compound synthesized in the same manner as in Production Example 4 and calcined at 1000° C. for 4 hours was further surface-treated with r-methacryloxypropyltrimethoxysilane. In the treatment, 6 wt% of r-methacryloxypropyltrimethoxysilane was added to the spherical inorganic oxide, and after refluxing in a water-ethanol solvent at 80°C for 2 hours, the solvent was removed with an evaporator. A vacuum drying method was used.

Next, bisphenol A diglycidyl methacrylate (hereinafter referred to as B15-G ki A) was used as a monomer.

) and triethylene glycol dimethacrylate (hereinafter referred to as T
It's called EGDMA. ) mixture (mixing ratio is Bis-G
MA/TEGDMA-3/7 molar ratio. ) was blended with the above inorganic oxide and sufficiently kneaded to obtain a paste-like composite material. At this time, the filling of the spherical inorganic oxide in the composite material
The viscosity of the paste was 72.8 wt%, which was appropriate for operation. Next, divide the paste into two equal parts, add N,N-dimethyl-p-)luidine as a polymerization accelerator to one side, and add 1wt% of benzoyl peroxide as a polymerization initiator to the other side, based on the vinyl monomer, and paste. AC former) and PACE) B (latter) were prepared.

Check the above paste A and paste B for 30 seconds.
As a result of measuring the physical properties of the product kneaded and hardened at room temperature, the compressive strength was 3800Kl/d-bending strength was 750K.
f/i, surface roughness 0.5 μm2 surface hardness 60.0. The toothbrush wear depth was 5.0μ. When the surface was polished using Nflex (manufactured by 3M), a smooth surface was easily obtained without excessively abrading the surface of the composite resin. Moreover, transparency was good.

Examples 2 to 4 Production Example 18 Using the spherical inorganic oxides obtained in Production Examples 2 and 3 (calcined at 1000°C for 4 hours), the same method as in Example 1 was carried out using the same monomer. A paste-like composite material was prepared, further cured, and the physical properties of the composite resin were measured. The results are also summarized in Table 1.

Examples 5 to 7 Using the spherical inorganic oxide used in Example 1, U-4HMA, U-4TM, and U-48M were used as vinyl monomer components.
A, tetramethylolmethane triacrylate (hereinafter referred to as T
It's called MMT. ) and methyl methacrylate (hereinafter referred to as MMA) were used, but a paste-like composite material was prepared in the same manner as in Example 1.

The mixing ratios of the and nil monomer components are shown in Table 2. The paste-like composite material was further cured in the same manner as in Example 1, and the physical properties of the composite resin were measured. The results are also shown in Table 2.

Claims (1)

[Claims] (1) A composite material comprising a spherical inorganic oxide whose main components are a polymerizable vinyl monomer, silica, and an oxide of a Group IV metal of the periodic table.