JPH0138044B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention provides at least one metal oxide selected from the group consisting of novel metal oxides of Groups 1, 2, 3, and 3 (hereinafter abbreviated as Group 1, Group 3, Group 3, and Group 3, respectively) of the periodic table. The present invention relates to a spherical inorganic oxide whose main constituents are two types of metal oxides and silica, and a method for producing the same. Inorganic oxides whose main constituents are silica and group metal oxides, group metal oxides, or group metal oxides have been known, but their shapes are amorphous and spherical. unknown. Also, a known manufacturing method is to mix silica and group metal oxides, group metal oxides, group metal oxides, and/or group metal oxides, and melt the mixture at a high temperature above the melting point to obtain a glass-like material. It was a method of crushing solid materials. 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. In addition, as another manufacturing method, alkoxysilane and group
By mixing alcoholates of group metals and/or group metals and hydrolyzing this, an agar-like gel is obtained, and by calcining the agar-like substance, silica and group metals, It is known to obtain group metal oxides. 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, and particularly having 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 composed of silica having a spherical shape with uniform particle diameter and a group metal oxide, group group metal oxide, group group metal oxide, group group metal oxide, group group metal oxide, group group metal oxide. Therefore, the object of the present invention is to produce a spherical inorganic material whose main constituents are at least two metal oxides selected from the group consisting of Group 3, Group 3, Group 3 metal oxides, and Group 3 metal oxides, and silica. An object of the present invention is to provide an oxide and a method for producing the same. Another object of the present invention is to provide an inorganic oxide having a particle size in the range of 0.1 to 1.0 μm and a very uniform particle size distribution, and a method for producing the same. Furthermore, another object of the present invention is to improve the mechanical strength and surface hardening of a composite material when used as a reinforcing material for a composite material, and to impart good properties such as transparency and surface smoothness. To provide a spherical inorganic oxide whose main constituents are silica and at least two metal oxides selected from the group consisting of oxides of metals of Group 3, Group 3, and Group 3, and a method for producing the same. be. Further objects of the invention will become apparent from the detailed description below. As a result of intensive research aimed at solving many of these technical problems, the present inventors have discovered that at least two metals selected from the group consisting of Group 3, Group 3, Group 3 metal oxides, and Group 3 metal oxides. We have succeeded in producing an inorganic oxide with a spherical shape, which consists of oxide and silica as the main components, and we have now proposed it here. The inorganic oxide of the present invention is an oxide of a silicon atom of silica and a group metal, group group, group group or group metal such as lithium oxide, sodium oxide, potassium oxide, magnesium oxide, calcium oxide, strontium oxide, barium oxide, Aluminum oxide, titanium oxide, zirconium oxide, hafnium oxide, tin oxide, lead oxide, etc. are bonded through oxygen, and are mainly from the group consisting of oxides of group metals, The constituent components are at least two selected metal oxides and silica. ^and oxides of metals of the above- ^mentioned groups, groups ^, _groups , _groups , etc. , M ² is a group metal, M ³ is a group metal, and M ₄ is a group metal). Of course, the influence of the composition ratio on the shape will vary depending on the type of M1/ ^2O , M2O, M3/ ₂ , and ^M4O2 , manufacturing method, manufacturing conditions, etc., but in general, it is a spherical inorganic oxide. When trying to obtain the desired amount, it is preferable to suppress the total composition ratio of M1/2O, ^M2O , _M3 / _2O3 , and ^M4O2 to 20 mol% or less, especially in the range of 0.01 to 15 mol%. When selecting the total composition ratio of M1/2O, M ² O, M3/2O ₃ and M ⁴ O ₂ , the particles are close to perfect spheres with uniform particle diameters. The composition ratios of M1/ ^2O , M2O, M3/ _{2O3 and} ^M4O2 can be confirmed by chemical analysis, but M1/ ^2O , M2O, M3 _{/ 2O3} and ^M4O2 Some types can 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 known, it can also be calculated from the raw material ratio. In the inorganic oxide of the present invention, the constituent components of silica and M1/2O, ^M2O , _M3 / _2O3 , and ^M4O2 generally exist chemically bonded, and these constituents are physically bonded. cannot be separated into 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, in the infrared spectrum, when M ⁴ O ₂ is TiO ₂ , a unique absorption can be observed at 950 cm ^-1 , and the refractive index of the inorganic oxide is between the refractive index of each of its constituent components; This can be confirmed from the fact that as the components of ⁴ O ₂ , such as TiO ₂ and ZrO ₂ , increase, the refractive index becomes higher than that of silica alone. The shape, particle size, particle size distribution, etc. of the inorganic oxide of the present invention can be measured by taking a scanning or transmission electron micrograph. Generally, the inorganic oxide of the present invention has a small particle size, for example, in the range of 0.1 to 1.0 μm, and its particle size distribution is extremely uniform. For example, the standard deviation value of the particle diameter can be set to 1.30 or less. At least two selected from the group consisting of M1/2O, M ² O, M3/2O ₃ and M ⁴ O ₂ provided in the present invention.
Inorganic oxides whose main constituents are metal oxides and silica have a specific surface area of 100 m ² /g or more, generally in the range of 100 to 200 m ² /g;
It may be less than 100 m ² /g, generally in the range of 1 to 50 m ² /g. Although the details will be described later, the inorganic oxide obtained by reacting and hydrolyzing the raw materials of both components in an alkaline solvent generally has a specific surface area of
It is large, 100m ² /g or more. If such an inorganic oxide is calcined at a temperature of 500°C or higher, generally from 500 to 1300°C, the specific surface area of the inorganic oxide will be reduced to less than 100 m ² /g. However, except for crystalline constituents of silica/periodic table group oxides/titanium, all inorganic oxides have almost the same composition ratio and spherical shape. . Most of the inorganic oxides of the present invention are essentially crystalline or a mixture of amorphous and partially crystalline, but M
Some types of 1/2O, M ² O, M3/2O ₃ and M ⁴ O ₂ are produced as a crystalline mixture. Generally, these determinations can be confirmed by analyzing the inorganic oxide of the present invention by means such as X-ray diffraction or refractive index measurement. In addition, on the surface of the inorganic oxide of the present invention -
Since some have OH groups bonded to them, the amount of OH groups can be confirmed by measurement using an alkali neutralization method. In general, those with a large specific surface area, i.e. before firing, are in the range of 1.0 to 2.0 mmol/g, and those with a small specific surface area, i.e., after firing, are in the range of 0.01 to 0.10 mmol/g.
It often has an OH group in the range of mol/g. Furthermore, the specific gravity and refractive index of the inorganic oxide of the present invention cannot be generally indicated because they differ depending on the type and composition ratio of the metal oxide.
Most commonly specific gravity 1.20-3.00 and refractive index 1.35
Many are in the range of ~1.70. As described above, the inorganic oxide of the present invention has the most characteristic use in that it is spherical in shape.
For example, when the inorganic filler of the present invention is used as a dental filler, the powder filling rate can be significantly increased, and as a result, not only can the mechanical strength and surface hardness of the dental filler be increased, It exhibits extremely useful effects in practical use, such as significantly improved transparency and surface smoothness. In addition to the above, the inorganic oxide of the present invention is suitably used in a wide range of applications such as catalysts, catalyst carriers, sintered materials, pigments, inorganic ion exchangers, and adsorbents. Since the inorganic oxide of the present invention has the various properties described above, it can be used for various purposes, but the method for producing it is not particularly limited as long as it provides the above-mentioned properties. The most typical method will be explained in detail below. (1) A mixed solution containing a hydrolyzable organosilicon compound and at least two metal organic compounds selected from the group consisting of hydrolyzable organic compounds of Group 3, Group 3, and Group 3 metals. of,
The organosilicon compound and the metal compound of Group 1, Group 3, Group 3, and Group 3 are dissolved in an alkaline solvent in which the reaction product is not substantially dissolved, and hydrolysis is performed to precipitate the reaction product. There is a way. There are various types of hydrolyzable organosilicon compounds, but examples of which are industrially easily available include alkoxysilanes represented by the general formula Si(OR) ₄ or low condensates obtained by partially hydrolyzing alkoxysilanes. may be used without particular limitation.
R in the general formula is an alkyl group, and lower alkyl groups such as methyl, ethyl, isopropyl, and butyl are preferably used. These alkoxysilanes and their low condensates may be used as commercially available products as they are or after being purified by distillation. Further, the hydrolyzable group metal compound, which is another raw material, is not particularly limited and any known compound can be used, but in general, the general formula M ¹ (OR'), M ₂ (OR′) ₂ ,
M ³ (OR′) ₃ , M ⁴ (OR′) ₄ (R′ is an alkyl group)
A metal alkoxide compound represented by the formula 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. where M ¹ is a group metal, M ² is a group metal M ³
is a Group metal, ^M4 is a Group metal, such as lithium, sodium, potassium, magnesium, calcium, strontium, barium, aluminum, titanium, zirconium, germanium, hafnium, tin or lead. used. Specific examples of the above-mentioned compounds that are generally suitably used in the present invention include organic sodium compounds such as NaOCH ₃ , NaOC ₂ H ₅ , NaOC ₃ H ₇ , and instead of the above-mentioned Na,
Compounds of group metals substituted with Li, K, etc., Mg
( _{OCH3 ) 2} , Mg( _OC2H5 ) ₂ , Mg( _OC3H7 ) ₂ , _Mg
(OC ₄ H ₉ ) ₂ , Mg (OC ₅ H ₁₁ ) ₂ and other organomagnesium compounds, and instead of the above Mg, Ca, Sr, Ba
Compounds of group metals substituted with Al, etc.
Compounds such as (OC ₂ H ₅ ) ₂ , Al(OC ₃ H ₇ ) ₂ , Al(OC ₄ H ₉ ) _2, compounds of group metals such as β in place of the above Al, Ti(O- _isoC3H7 ) _{4 ,} Ti
(O- _nC4H9 ) ₄ ,Ti( _{O - CH2CH} ( _C2H5 )
_C4H9 ) ₄ , Ti ₍ O- _C17H35 ) ₄ , _Ti (O-
isoC ₃ H ₇ ) ₂ [CO(CH ₃ )CHCOCH ₃ ] ₂ , Ti(O−
nC ₄ H ₉ ) ₂ [OC ₂ H ₄ N(C ₂ H ₄ OH) ₂ ] ₂ , Ti(OH) ₂
[OCH (CH ₃ ) COOH] ₂ , Ti (OCH ₂ CH (C ₂ H ₅ )
CH(OH) _C3H7 ) ₄ , Ti ₍ O _{- nC4H9} ) ₂
(OCOC ₁₇ H ₃₅ ), and group metal compounds in which Ti is replaced with Zr, Ge, Hf, Sn, Pb, etc. Also, CaCl ₂ , Ca
Compounds such as [HOC ₆ H ₄ COO] _{2.2H 2} O can also be suitably used. In the present invention, the alkoxysilane or its 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 generally methanol, ethanol, isopropanol, butanol, Alcohol solvents such as isoamyl alcohol, ethylene glycol, and propylene glycol 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. . Furthermore, it is generally preferable that the concentration of the solution in which the raw materials are dissolved is 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. It may be determined appropriately by taking these into consideration. Generally, it is most preferable to use the raw material at a concentration of 50% by weight or less, preferably from 5 to 50% by weight. In order to make the inorganic oxide of the present invention into a spherical shape, generally the group group, group group,
It is preferable to control the mixing ratio of at least two metals selected from the group consisting of Group 3 and Group 3 metals and silicon (Si) and the amount of water added to the mixed solution. For example, water in a raw material mixed solution is included in the solvent or is actively added to hydrolyze the organic silicon compound of the raw material, but if the amount of water is too large, it may cause inorganic oxides to be dissolved. It is generally difficult to form a spherical shape, 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 mixed solution is preferably small, and generally the molar ratio is _H2O /M≧1.0, preferably _H2O /M≧2.0, and It is preferable to select it so as to satisfy the condition of H ₂ O/Si≦4, preferably H ₂ O/Si≦1.0.
Here, M is the number of moles of group metal.
However, when the metal contained in the mixed solution is zirconium, a spherical inorganic oxide can be obtained even if the mixed solution does not contain water. Similarly, in the case of group metals and group metals, spherical inorganic oxides tend to be more easily obtained when water is not added to the mixed solution. Also the amount of water added into the mixed solution
It is also preferable to control the mixing ratio of Si and M, and it is generally preferable to select the mixing ratio so that M/Si+M≦0.3, preferably M/Si+M≦0.2. Here, M is the total number of moles of at least two metals selected from the group consisting of Group 3, Group 3, Group 3, and Group 3 metals. It is currently not clear what effect the above conditions have on the production of inorganic oxides, but if the metal contained in the mixed solution is a group metal and/or group metal, the inorganic oxide It is estimated that an alkoxysilane having a silanol group must be present as an intermediate during the production of . However, although the reason is not clear, in the case of group metal and/or zirconium, it may not be necessary for an alkoxysilane having a silanol group to be present. This phenomenon can also be inferred from the following facts. That is,
For example, when tetraethyl silicate (Si(Oεt) ₄ ) is hydrolyzed by adding water, it is confirmed by analytical means such as gas chromatography that the following intermediates with silanol groups are present immediately after hydrolysis. I can do it.

【formula】

【formula】

【formula】

【formula】

[Formula] The above intermediates are highly reactive and react with each other or with other ethyl silicates to form a high condensate through dealcoholization and disappear. When the intermediates are mixed in appropriate amounts, the final reaction product, the inorganic oxide, becomes spherical. When using distilled commercially available tetraethyl silicate as a starting material, for example, after adding a predetermined amount of water,
The desired intermediate can be obtained in 2 to 3 hours at 25°C and in a few minutes to 10 minutes at 60°C, but for raw materials that are difficult to hydrolyze, hydrolysis accelerators such as
Hydrolysis can be promoted by adding a mineral acid such as 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 cause hydrolysis to occur appropriately. Therefore, it is clear from the above results that the amount of water in the raw material mixture solution, that is, the amount of water for hydrolyzing tetraethylsilicate, has a large effect on the shape of the obtained inorganic oxide, that is, whether it is spherical or not. Will.
Furthermore, among at least two metal compounds selected from the group consisting of Group 3, Group 3, Group 3, and Group 3 metal compounds, when the metal compound is a Group 3 or Group 3 metal compound; It is presumed that even if there is no alkoxysilane having a silanol group in the mixed solution, intermediates (for example, complex alkoxides) with group and/or group metal alkoxysilanes are formed. The abundance ratio of Si and at least two metals selected from the group consisting of Group 3, Group 3, Group 3, and Group 3 metals in the raw material mixed solution influences the refractive index of the obtained 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 Group 3, Group 3, Group 3, and/or Group metal compound. This is because a solution of an organosilicon compound dissolved in a alkaline solvent and a solution of a compound of a group metal, a group metal, a group metal, and/or group metals are added separately without pre-mixing them. Even if the reaction is carried out, an inorganic oxide, especially one having a spherical shape, cannot be obtained. Therefore, in producing the inorganic oxide of the present invention, it is necessary to prepare a solution in which both raw materials are mixed together 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 standing at 0 to 80° C. for several minutes to several hours in order to uniformly disperse and react both raw materials. In particular, when preparing a mixed solution without adding water, it is preferable to reflux the solution at a high temperature. The raw material mixed solution prepared as above is then added to an alkaline solvent in which both of the raw materials are dissolved but the inorganic oxide is not substantially dissolved, and the solution is added to an alkaline solvent in which both the raw materials are dissolved but the inorganic oxide is not substantially dissolved. At least two selected from the group consisting of metal oxides
This precipitates an inorganic oxide whose main components are a metal oxide and silica. The solvent that dissolves both raw materials but does not substantially dissolve the produced inorganic oxide is not particularly limited, and known organic solvents may be used. Solvents that are generally suitably used are the same alcoholic solvents as mentioned above as solvents for the organosilicon compounds and compounds of Group 3, Group 3, Group 3 and/or Group metals, or ether solvents, ester solvents, etc. It is a water-containing solvent consisting of water and a mixed solvent in which an organic solvent is partially added 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. The shape of the inorganic oxide of the present invention, particularly the particle size of the spherical particles, is affected by factors such as the type of organic solvent, the amount of water, and the alkali concentration, so it is recommended to determine these conditions appropriately in advance. preferable.
Generally, the alkaline concentration of alkaline solvent is 1.0
It is preferable to select within the range of ~10 mole/
The higher the alkali concentration, the larger the particle size of the obtained inorganic oxide tends to be. The amount of water in the alkaline solvent is required to further promote hydrolysis and generate inorganic oxides, and is generally preferably selected from the range of 0.5 to 50 mole/mole/. Generally, the higher the concentration of water, the larger the particle size of the obtained inorganic oxide tends to be. Furthermore, another factor that influences the particle size of the inorganic oxide is the type of organic solvent, and generally the particle size of the obtained inorganic oxide tends to increase as the number of carbon atoms increases. 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 may be generally carried out within a range of several minutes to several hours. The reaction temperature varies depending on various conditions and cannot be absolutely limited, but it is usually 0°C to 40°C under atmospheric pressure.
What is necessary is just to carry out preferably at 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 mentioned above, the inorganic oxides obtained in this way are from group 3 of the periodic table.
The main constituents are at least two metal oxides selected from the group consisting of oxides of metals of Group 3, Group 3, and Group 3 metals, and silica, and the specific surface area is
100m ² /g or more. By selecting the various conditions as described above, the resulting inorganic oxide has a spherical shape, generally has an excellent particle size distribution in the range of 0.1 to 1.0 μm, and has a standard deviation value of 1.30 or less. (2) In the method of (1) above, seeds made of silica polymer that will serve as a nucleus for precipitation are pre-existing in an alkaline solvent, and then the above-mentioned
There is a method of obtaining inorganic oxides by carrying out a reaction similar to (1). The seeds used in the above method are not particularly limited 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, by further hydrolyzing the alkoxysilane or its low condensate in advance,
First, seeds made of silica polymer are generated, and the same reaction as in (1) above is carried out in the presence of the silica polymer to obtain an inorganic oxide. The alkoxysilane or its low condensate is hydrolyzed into a silica polymer in a solvent that dissolves the alkoxysilane but does not dissolve the resulting 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 alkoxysilane 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 a soluble solvent as explained in (1) above, and 1
It is preferable to adjust the concentration to 50% by weight. After producing the silica polymer, the inorganic oxide may be precipitated in the same manner as in (1) above, followed by separation and drying. The inorganic oxide thus obtained contains silica as a core, at least two metal oxides selected from the group consisting of oxides of metals of Groups 1, 2, 3 and 3 of the periodic table, and silica. Since it is an inorganic oxide mainly composed of , the resulting particle size distribution is particularly good. The specific surface area of the obtained inorganic oxide is 100 m ² /g or more, and the particle size is about 0.1 to 1.0 μm. (3) A mixed solution containing a hydrolyzable organosilicon compound and at least two metal compounds selected from the group consisting of hydrolyzable compounds of Groups 1, 2, 3, and 3 of the periodic table metals. of,
In an alkaline solvent in which the organosilicon compound and at least two metal compounds selected from the group consisting of compounds of metals of Groups 1, 2, 3, and 3 of the periodic table are dissolved, but the reaction product is not dissolved. There is a method in which the reaction product is precipitated by adding it to the reaction system and performing hydrolysis, and then adding a hydrolyzable organosilicon compound to the reaction system and causing the hydrolysis. In the method (3) above, the main constituents are at least two metal oxides selected from the group consisting of oxides of metals of Groups 1, 2, 3 and 3 of the periodic table, and silica. The steps up to the step of precipitating the inorganic oxide are the same as in (1) above, but in this method, after the inorganic oxide is precipitated, an organic silicon compound is added and reacted. The organosilicon compound to be reacted at the end has the general formula Si(OR) ₄ (where R is an alkyl group) used as the raw material.
Alkoxysilanes represented by or lower condensates thereof can be used without particular limitation. Further, 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. In addition, in order to cause the alkoxysilane or its low condensate to react with the precipitate, the alkoxysilane needs to undergo hydrolysis, so the presence of water is necessary in the reaction solvent. The amount of water is mainly composed of silica and at least two metal oxides selected from the group consisting of oxides of metals of Groups 1, 2, 3, and 3 of the periodic table in (1) above. The conditions are the same as those for precipitating the reaction product as a component. Furthermore, 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 concentration should be lower. Generally, it is used at 50% by weight or less, preferably 1 to 30% by weight. It's good to do that. Further, the addition time of the alkoxysilane solution may vary depending on the amount of solvent 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 precipitate is present without dissolving it in the solvent, but this method is difficult to control the reaction industrially, so it is not possible to do so. It's better to leave it alone. The precipitated inorganic oxide obtained by the above method may be separated and then dried. Further, the inorganic oxide is at least two selected from the group consisting of oxides of metals of Groups 1, 2, 3, and 3 of the periodic table.
The main constituents are seed metal oxides and silica, and the specific surface area is 100 m ² /g or more. However, due to the manufacturing method, the particle surface layer of inorganic oxides is covered with only silica or a layer with high silica content, and the inside of the particle is covered with metal oxides of Groups 1, 2, 3, and 3 of the periodic table. It is estimated that the structure is a combination of at least two metal oxides selected from the group consisting of silica and silica. 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 in the same manner as in the method (2) above, and then the same reaction as in (3) above is carried out to remove the inorganic This is a method of obtaining 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 is an oxide of at least two metals selected from the group consisting of oxides of metals of Groups 1, 2, 3, and 3 of the periodic table, mainly containing silica polymer seeds. There is a layer mainly composed of silica and silica, and on the surface there is an inorganic oxide covered with a layer mainly composed of silica. Furthermore, the specific surface area of the inorganic oxide is as large as 100 m ² /g or more, and the particle size of the spherical body is 0.1 m 2 /g or more.
It is possible to obtain particles with a standard deviation value of 1.30 or less in the range of ~1.0 μm. The inorganic oxides obtained by the above methods (1), (2), (3), and (4) are mainly composed of white to yellowish white amorphous powder, especially spherical particles. The results obtained are useful. As mentioned above, the inorganic oxide thus obtained generally has a large specific surface area of 100 m ² /g or more, so it can be used as a catalyst.
Suitable for use in fields requiring specific surface area such as catalyst carriers and adsorbents. Some of the inorganic oxides provided by the present invention have an extremely reduced number of -OH groups on their surfaces by calcining the products obtained by the methods (1) to (4) above. The firing method is not particularly limited and may be any known method.
It may be fired at a temperature of 200 to 1300°C or higher. In addition, depending on the content of metal oxides in Group 3 of the periodic table, the inorganic oxide may melt within the temperature range, lose its spherical shape, and become amorphous. It is preferable to select a firing temperature depending on the content of metal oxide. By firing, the specific surface area of the inorganic oxide becomes smaller.
When fired at a temperature of 500° C. or higher, the specific surface area becomes less than 100 m ² /g. Furthermore, when a 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 size 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 material. There are even cases where it happens. When the above-mentioned inorganic oxide of 100 m ² /g or more and whose constituent components are silica/periodic table group oxide/titanium is fired at 500°C or higher, especially 1000°C or higher, it becomes a crystalline inorganic oxide. Therefore, its properties are somewhat different from the inorganic oxide of the present invention.
Therefore, such crystalline inorganic oxides are excluded from the present invention. The inorganic oxide obtained after the calcination has excellent properties and is excellent as a powder component of dental fillers, for example. The composite material used as a powder component of a dental filler will be described below. For example, if the polymerizable vinyl monomer and particle size
It exhibits excellent properties when made into a composite material consisting of the above-mentioned fired spherical particles having a size in the range of 0.1 to 1.0 μm. One component of the composite is a polymerizable vinyl monomer. The vinyl monomer is not particularly limited, and known ones commonly used as dental composite materials can be used. The most typical vinyl monomer is a polymerizable vinyl monomer having an acrylic group and/or a methacrylic group. Specifically, examples of vinyl monomers having an acrylic group and/or methacrylic group include 2,2-bis[4(2-hydroxy-3-
Preferred are methacryloxypropoxy)phenyl]propane, methyl methacrylate, bismethacryloethoxyphenylpropane, triethylene glycol dimethacrylate, diethylene glycol dimethacrylate, tetramethylol triacrylate, tetramethylolmethane trimethacrylate, trimethylolethane trimethacrylate, etc. . Also preferably used is a vinyl monomer having a urethane structure represented by the following structural formula. However, in the above formula, _R1 , _R2 , _R3 and _R4 are the same or different H or _CH3 , (-A)- is ( _-CH2 ) _-6 ,

[Formula] or

[Formula] is preferred. Since these vinyl monomers are known as dental materials, they may be used alone or in combination as required. Another component of the composite material is the inorganic oxide. It is preferable to use spherical particles having a particle size in the range of 0.1 to 1.0 μm and a standard deviation value of the particle size distribution within 1.30 as the inorganic oxide. The above particle size, particle shape, and particle size distribution are all very important factors as long as they are used in dental composite materials. For example, if the above particle size is smaller than 0.1 μm, the viscosity will increase significantly when mixed with a polymerizable vinyl monomer to form a paste mixture, and if you try to prevent the viscosity increase by increasing the blending ratio, Since the operability deteriorates, it cannot be used as a material for practical use. If the particle size is larger than 1.0 μm, it is not preferable because there are defects such as a decrease in the abrasion resistance or surface smoothness of the resin after polymerization and curing of the vinyl monomer, and a decrease in surface hardness. Furthermore, if the standard deviation value of the particle size distribution is larger than 1.30, the operability of the composite material will be low, so that the composite material cannot be used for practical use. Furthermore, even if the inorganic oxide has a particle size in the range of 0.1 to 1.0 μm and the standard deviation of the particle size distribution is within 1.30, if the particle shape is not spherical, the wear resistance will be poor.
The surface smoothness, surface hardness, etc. cannot be satisfactory. For example, when using the above composite materials as dental restorative materials, not only is operability an important factor, but also the mechanical strength, abrasion resistance, surface smoothness, etc. of the resulting cured composite resin must be sufficiently improved. must be kept in good condition. Therefore, it is generally preferable to select the amount of the inorganic oxide to be added within a range of 70 to 90% by weight. In addition, when used as the above-mentioned dental composite restorative material, the inorganic oxide, the vinyl monomer, and the polymerization are generally prepared in a paste-like mixture consisting of the inorganic oxide, a polymerizable vinyl monomer, and a polymerization accelerator (for example, a tertiary amine compound). A method is preferably used in which a paste-like mixture consisting of an 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. Composite resin made by curing the above composite materials has no inferiority in mechanical strength such as compressive strength compared to conventional ones, and has excellent wear resistance and surface smoothness, as well as high surface hardness and surface polishing. It has many excellent features such as being very easy to finish and improving transparency. However, the reason why such characteristics appear is not necessarily clear at present, but the inventors of the present invention think as follows. In other words, by using an inorganic oxide in which the first particles are spherical and have a uniform particle size such that the standard deviation value of the particle size distribution is within 1.30, it is possible to achieve a wide particle size distribution compared to the conventional one. Compared to the case of using fillers with irregular shapes, the inorganic oxide is more uniformly and densely packed into the composite resin obtained by curing, and secondly, the particle size range is 0.1 to 1.0 μm. By using particles within the range of
Compared to using conventional inorganic fillers,
The polished surface of the composite resin after curing becomes smooth, and on the other hand, the total specific surface area of the filler is smaller than when using ultrafine particle fillers that are mainly composed of fine particles of several tens of nanometers, and therefore, suitable operability is achieved. Possible reasons include the fact that a large amount of filler can be filled under the conditions of . 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 becomes extremely A composite resin with excellent transparency can be obtained. By blending the specific 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 merits by blending two components, a polymerizable vinyl monomer component and a specific inorganic oxide component, but in addition to these components, it also contains additives commonly used as dental restorative materials. Components can also be added as needed. Typical of these additive components are as follows. Examples include radical polymerization inhibitors, coloring pigments for color matching, and ultraviolet absorbers. 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 unless otherwise specified. (1) Refractive index A solvent with the same refractive index as the refractive index of the inorganic oxide sample was prepared, and the refractive index was set as the refractive index of the sample. The solvent was prepared by suspending the sample in a solvent and preparing the composition of the solvent at a constant temperature so that it appeared 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 Abe refractometer. (2) Number of surface OH groups Weigh 2.00 of the inorganic oxide sample (take it as Wg)
Add 0.05N NaOH to a 100ml Erlenmeyer flask.
80 ml of the aqueous solution was added, the mixture was sealed with a rubber stopper, and the mixture was left stirring for 12 hours. Thereafter, the inorganic oxide and the solution were separated using a centrifuge, and 10 ml of the solution was taken as a pepitope and subjected to neutralization titration with a 0.05N aqueous HCl solution. Let the HCl aqueous solution required for neutralization be Aml. The same operation is performed without adding the sample, and the HCl aqueous solution required for neutralization is designated as Bml. The amount of surface -OH groups per unit weight of inorganic oxide (Xm
mole/g) is calculated by the following formula. X=(B-A)×0.05×8/W (3) Specific gravity Specific gravity was measured according to the pycnometer method. (4) Standard deviation value of particle size and particle size distribution Take a scanning electron micrograph of the powder, and calculate the number of particles observed within the unit field of view of the photograph (n),
and the particle diameter (diameter x _i ), which is calculated using the following formula. (5) Specific surface area Shibata Chemical Equipment Co., Ltd. Rapid surface measuring device SA−
1000 was used. The measurement principle is the BET method. (6) Composite paste preparation and curing method First, amorphous silica surface-treated with γ-methacryloxypropyltrimethoxysilane and vinyl monomer are placed in a predetermined ratio in an agate mortar to form a uniform paste. It was thoroughly kneaded. Next, the paste was divided into two equal parts, and a polymerization accelerator was further added to one of the pastes, and the mixture was thoroughly mixed (this is referred to as paste A). Further, an organic peroxide catalyst was added to the other paste and thoroughly mixed (this is referred to as paste B). Next, equal amounts of paste A and paste B were kneaded for about 30 seconds, filled into a mold, and hardened. (7) Compressive strength Paste A and paste B were mixed, polymerized for 30 minutes at room temperature, and then immersed in water at 37°C for 24 hours to obtain test pieces. Its size and shape are cylindrical with a diameter of 6 mm and a height of 12 mm. This test piece was tested using a testing machine (UTM manufactured by Toyo Baudouin).
-5T) and crosshead speed 10
Compressive strength was measured in mm/min. (8) Bending strength Mix paste A and paste B and
After polymerizing for 30 minutes, the test piece was immersed in water at 37°C for 24 hours. Its size and shape are 2
It has a prismatic shape with dimensions of 2 x 25 mm. The bending test was conducted using a bending test device with a distance between fulcrums of 20 mm attached to Toyo Baudouin's UTM-5T, and a crosshead speed of 0.5 mm/min. (9) Toothbrush wear depth and surface roughness Mix paste A and paste B and
After polymerizing for 30 minutes, the test piece was immersed in water at 37°C for 24 hours. Its size and shape are
It is a plate shape of 1.5 x 10 x 10 mm. After abrading the test piece for 1500 m with a toothbrush under a load of 400 g, the ten-point average roughness was determined using a surface roughness meter (Surfcom A-100). Further, the wear depth was determined by dividing the wear weight by the density of the composite resin. (10) Surface hardness Mix paste A and paste B and heat at room temperature.
After polymerizing for 30 minutes, the test piece was immersed in water at 37°C for 24 hours. Its size and shape are
It is disc-shaped, measuring 2.5 x 10 mm. The measurement used a micropurinelle hardness test. Furthermore, the abbreviations used in the examples are as follows unless otherwise specified. The firing time for the inorganic oxides in Tables 1 to 20 was 4 hours unless otherwise specified. AM; amorphous, AN; anatase, AM+
AN: Mixture of amorphous and anatase, AM+H: Mixture of amorphous and tetragonal zirconia, IPA: Isopropanol, MeOH: Methanol, BuOH: Butanol, Example 1 Tetraethylsilicate (Si(OC ₂ H ₅ ) ₄ ) obtained by distilling 1.8 g of water, product name manufactured by Nippon Colcoat Chemical Co., Ltd.;
Dissolve 104 g of ethyl silicate 28) in 0.2 methanol, hydrolyze this solution while stirring at room temperature for about 2 hours, and add 17.0 g of tetrabutyl titanate (Ti(onC ₄ H ₉ ) ₄ , manufactured by Nippon Soda) to this solution. was added to a solution dissolved in isopropanol 1.0 with stirring to prepare a mixed solution (A) of tetraethyl silicate hydrolyzate and tetrabutyl titanate. Next, barium bisisopentoxide 7.8
g and 104 g of tetraethyl silicate in methanol.
1.0, the solution was refluxed at 90°C under nitrogen atmosphere for 30 minutes, then warmed to room temperature, and the mixed solution
(B) was prepared. Further, the mixed solution (A) and the mixed solution (B) were mixed at room temperature to form a mixed solution (C). Next, fill a glass reaction container with an internal volume of 10 with a stirrer with 2.5 methanol, add 500 g of ammonia aqueous solution (concentration 25 wt%) to prepare an ammoniacal methanol solution, and add the previously prepared mixture to this solution. Solution (C) was added over about 4 hours while maintaining the temperature of the reaction vessel at 20°C. A few minutes after the addition started, the reaction solution became milky white. 1 more after addition
After stirring for a period of time, the solvent was removed from the milky white reaction solution using an evaporator, and the mixture was further dried under reduced pressure at 80°C to obtain a milky white powder. 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 0.12 to 0.26 μm, and the standard deviation value of the particle size was 1.06. The specific surface area determined by BET method was 130 m ² /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. Furthermore, thermal changes and weight changes were measured using a differential thermal analyzer and a heat transfer balance. As a result, endotherm and weight loss, which is thought to be due to dehydration, was observed at around 100°C, and furthermore, exothermic weight loss was observed at around 200-650°C. Thereafter, almost no thermal or weight changes were observed up to 1000°C. The specific surface area of the powder after firing at 800℃ for 2 hours is
17 m ² /g, specific gravity 2.49, and refractive index 1.52 to 1.53, and X-ray analysis showed gentle mountain-shaped absorption, confirming that it had an amorphous structure. Furthermore, the content of TiO ₂ and BaO determined by fluorescent X-ray analysis agreed with the calculated value from the amount of charge, and the yield also agreed with the value calculated from the amount of charge. The measured value of the TiO ₂ content of the powder was 4.7 mole% (calculated value 4.7 mole%), the measured value of the BaO content was 2.3 mole (calculated value 2.3 mole%), and the measured value of the yield of the powder was 67.0 g ( Calculated value: 67.9g). Examples 2 to 4 All experiments were carried out under the same conditions as in Example 1 except that the organosilicon compound, metal organic compound, and water in the mixed solution shown in Table 1 were used. The results were as shown in Table 1. Furthermore, all of the obtained inorganic oxides were spherical in shape as a result of observation using scanning electron micrographs. Examples 5 to 7 All experiments were carried out under the same conditions as in Example 1, except that the raw material composition of the mixed solution (A) shown in Table 2 was used. The results were as shown in Table 2. Furthermore, all of the obtained inorganic oxides were spherical in shape as a result of observation using scanning electron micrographs. Examples 8 to 10 All experiments were carried out under the same conditions as in Example 1, except that the composition of the ammoniacal alcohol shown in Table 3 was used. The results were as shown in Table 3. Furthermore, all of the obtained inorganic oxides were spherical in shape as a result of observation using scanning electron micrographs. Examples 11 to 18 All experiments were carried out under the same conditions as in Example 1, except that the organic silicon compound, metal organic compound, and water in the mixed solution shown in Table 4 were used. The results are in Table 4
It was as shown in. Furthermore, all of the obtained inorganic oxides were spherical in shape as a result of observation using scanning electron micrographs. Example 19 An ammoniacal methanol solution having the same composition as that used in Example 1 was prepared in a glass reaction vessel with an internal volume of 10 and equipped with a stirrer. Next, to create silica seeds, a solution of 4.0 g of tetraethyl silicate dissolved in 100 ml of methanol as an organic silicon compound solution was added to this ammoniacal methanol solution over about 5 minutes, and 5 minutes after the addition was completed, the reaction solution became slightly milky white. When the temperature reached 100, continue to add a mixed solution (C) having the same composition as that used in Example 1.
The mixture was added to the reaction vessel over a period of 4 hours while maintaining the temperature of the reaction vessel at 20°. As the mixed solution (C) was added, it became a milky white suspension. After the addition was completed, stirring was continued for another hour, and then the solvent was removed from the milky white reaction liquid using an evaporator, and the mixture was further dried under reduced pressure at 80°C to obtain a milky white powder. As a result of observation using scanning electron micrographs, the shape of the powder was spherical.
The particle size was in the range of 0.15 to 0.26 μm, and the standard deviation value of the particle size was 1.05. Further, the specific surface area determined by the BET method was 120 m ² /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. After firing at 800°C for 4 hours, the powder has a specific surface area of 15 m ² /g, a specific gravity of 2.49, and a refractive index of 1.52~
1.53, and X-ray analysis showed gentle mountain-shaped absorption, confirming that it had an amorphous structure. Furthermore, the contents of TiO ₂ and BaO determined by fluorescent X-ray analysis agreed with the calculated values from the charging amount, and the yield also agreed with the calculated values from the charging amount. The actual value of the content of TiO ₂ in the powder was 4.6 mole% (the calculated value was 4.6 mole%), and the actual value of the yield of the powder was 68.0 g (the calculated value was 69.0 g). Examples 20 to 22 All experiments were carried out under the same conditions as in Example 19, except that the composition of the organosilicon compound solution for producing silica seeds shown in Table 5 was used. The results were as shown in Table 5. Furthermore, all of the obtained inorganic oxides were spherical in shape as a result of observation using transmission electron micrographs. Examples 23 to 28 All experiments were conducted under the same conditions as in Example 19, except that the organic silicon compound, metal organic compound, and water in the mixed solution shown in Table 6 were used. The results were as shown in Table 6. Furthermore, all of the obtained inorganic oxides were spherical in shape as a result of observation using scanning electron micrographs. Examples 29 to 31 All experiments were carried out under the same conditions as in Example 19, except that the composition of the ammoniacal alcohol shown in Table 7 was used. The results were as shown in Table 7. Furthermore, all of the obtained inorganic oxides were spherical in shape as a result of observation using scanning electron micrographs. Examples 32 to 39 All experiments using the organosilicon compound, metal organic compound, and water in the mixed solution shown in Table 8 were carried out under the same conditions as in Example 19. The results were as shown in Table 8. Further, as a result of observation using scanning electron micrographs, all of the obtained inorganic oxides were spherical in shape. Example 40 An ammoniacal methanol solution having the same composition as that used in Example 1 was prepared in a glass reaction vessel with an internal volume of 10 and equipped with a stirrer. Next, a mixed solution (C) having the same composition as that used in Example 1 was added to this ammoniacal methanol over a period of 2 hours while maintaining the temperature of the reaction vessel at 20° C. to precipitate a reaction product. After the addition was completed, a solution containing 104 g of tetraethylsilicate and 0.5 g of methanol was added over about 2 hours to the system in which the reaction product had precipitated. After the addition was completed, stirring was continued for an additional hour, and then 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, the shape of the powder was spherical, the particle size was in the range of 0.15 to 0.30 μm, and the standard deviation value of the particle size was 1.05. According to X-ray analysis, a gentle mountain-shaped absorption centered at 2θ = 25° was observed, indicating that the material had an amorphous structure. Also, the specific surface area by BET method is
It was 125m ² /g. 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 at 800℃ for 1 hour, the specific surface area of the powder is 15m ² /g, and the number of surface −OH groups is 0.20mmole/g.
g, specific gravity is 2.44, and refractive index 1.51 to 1.52,
In X-ray analysis, gentle mountain-shaped absorption was observed, and it was confirmed that the material had an amorphous structure.
Furthermore, the ratio of amounts of Si, Ti, and Ba determined by fluorescent X-ray analysis was consistent with the ratio of the amounts charged, and the yield was also approximately equal to the value calculated from the amounts charged. _TiO2 3.2mole%,
It was confirmed that it was a spherical inorganic oxide with an amorphous structure consisting of 1.6 mole% BaO and 95.2 mole% SiO ₂ . Examples 41 to 43 All experiments were carried out under the same conditions as in Example 40, except that the composition of the organosilicon compound solution added after the reaction products shown in Table 9 were precipitated. The results were as shown in Table 9. Further, as a result of observation using a scanning electron microscope, all of the obtained inorganic oxides had a spherical shape. Examples 44 to 49 All experiments were carried out under the same conditions as in Example 40, except that the raw material composition of the mixed solution shown in Table 10 was used. The results were as shown in Table 10. Further, as a result of observation using a scanning electron microscope, all of the obtained inorganic oxides had a spherical shape. Examples 50 to 52 All experiments were carried out under the same conditions as in Example 40, except that the composition of the ammoniacal alcohol shown in Table 11 was used. The results were as shown in Table 11. Further, as a result of observation using scanning electron micrographs of the obtained inorganic oxides, they were all spherical in shape. Examples 53 to 60 All experiments were carried out under the same conditions as in Example 40, except that the raw material composition of the mixed solution shown in Table 12 was used. The results were as shown in Table 12. In addition, the obtained inorganic oxide was observed using scanning electron microscopy.
All were spherical in shape. Example 61 An ammoniacal methanol solution having the same composition as that used in Example 1 was prepared in a glass reaction vessel with an internal volume of 10 and equipped with a stirrer. Next, a solution of 4.0 g of tetraethyl silicate dissolved in 100 ml of methanol as an organosilicon compound solution was added to this ammoniacal methanol solution over a period of about 5 minutes to prepare silica seeds. When the color becomes milky white, continue adding a mixed solution having the same composition as that used in Example 1.
(C) was added to the reaction solution over about 2 hours while maintaining the temperature of the reaction vessel at 20°C to precipitate the reaction product. Thereafter, a solution containing 104 g of tetraethyl silicate and 0.5 g of methanol was added over about 2 hours to the system in which the reaction product had precipitated. After the addition was completed, stirring was continued for an additional hour, and then 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, the shape of the powder was spherical, the particle size was in the range of 0.17 to 0.32 μm, and the standard deviation value of the particle size was 1.05. According to X-ray analysis, a gentle mountain-shaped absorption centered at 2θ = 25° was observed, indicating that the material had an amorphous structure. Also, the specific surface area by BET method is
It was 120m ² /g. 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 at 800℃ for 4 hours, the specific surface area of the powder is 14m ² /g, and the number of -OH groups on the surface is 0.25mmole/g.
g, specific gravity is 2.44, and refractive index 1.51-1.52,
X-ray analysis showed a gentle mountain-shaped absorption centered at 2θ = 22°, indicating that it had an amorphous structure. The amount ratio of Si, Ti, and Ba determined by fluorescent X-ray analysis matched the amount ratio of the ingredients, and the yield also almost agreed with the value calculated from the amount of ingredients. _TiO2 3.1mole%,
It was confirmed that it was a spherical inorganic oxide with an amorphous structure consisting of 1.6 mole% BaO and 95.3 mole% SiO ₂ . Examples 62 to 64 Everything was the same as Example 61 except that the composition of the organosilicon compound solution for producing silica seeds and the composition of the organosilicon compound solution added after precipitating the reaction product were as shown in Table 13. It was conducted under the following conditions. The results were as shown in Table 13. Furthermore, all of the obtained inorganic oxides were spherical in shape as a result of observation using scanning electron micrographs. Examples 65 to 70 All experiments were carried out under the same conditions as in Example 61 except that the organosilicon compound, metal organic compound, and water in the mixed solution shown in Table 14 were used. The results were as shown in Table 14. In addition, the obtained inorganic oxide is
As a result of observation using scanning electron micrographs, all of the particles were spherical in shape. Examples 71 to 73 All experiments were carried out under the same conditions as in Example 61, except that the composition of the ammoniacal alcohol shown in Table 15 was used. The results were as shown in Table 15. Further, as a result of observation using a scanning electron microscope, all of the obtained inorganic oxides had a spherical shape. Examples 74 to 81 All experiments were carried out under the same conditions as in Example 61, except that the raw material composition of the mixed solution shown in Table 16 was used. The results were as shown in Table 16. Further, as a result of observation using a scanning electron microscope, all of the obtained inorganic oxides had a spherical shape. Example 82 An inorganic oxide synthesized in the same manner as in Example 11 and calcined at 800°C for 4 hours was further surface-treated with γ-methacryloxypropyltrimethoxysilane. The treatment was performed by adding 6 wt% of γ-methacryloxypropyltrimethoxysilane to the inorganic oxide, refluxing it in a water-ethanol solvent at 80°C for 2 hours, removing the solvent with an evaporator, and drying in vacuum. Ivy. Next, as a vinyl monomer, a mixture of bisphenol A diglycidyl methacrylate (hereinafter referred to as Bis-GMA) and triethylene glycol dimethacrylate (hereinafter referred to as TEGDMA) (mixing ratio is Bis-GMA/TEGDMA = 3/7 molar ratio). ) was blended with the above inorganic oxide and thoroughly kneaded to obtain a paste-like composite material. At this time, the filling amount of inorganic oxide in the composite material was 73.6 wt%, and the viscosity of the paste was appropriate for operation. Next paste 2
N,N-dimethyl-P-toluidine was added as a polymerization accelerator to one side, and benzoyl peroxide as a polymerization initiator was added to the other side in an equal amount of 1 wt% based on the vinyl monomer to prepare paste A (former) and paste. B (latter) was prepared. Take equal amounts of Paste A and Paste B above and 30
After kneading and hardening at room temperature for a few seconds, the physical properties were measured, and the results showed a compressive strength of 3700 kg/cm ² and a bending strength.
The weight was 80 kg/cm ² , the surface roughness was 0.5 μm, the surface hardness was 60.0, and the toothbrush wear depth was 5.5 μm. When the surface was polished using Soflex (manufactured by 3M), a smooth surface was easily obtained without excessively abrading the surface of the composite resin. or,
Transparency was good. Examples 83 to 85 Using the inorganic oxides of Examples 19, 40, and 61 (calcined at 800°C for 4 hours), paste was prepared using the same vinyl monomer as in Example 82 in the same manner. was prepared, further cured, and the physical properties of the composite resin were measured. The results are also summarized in Table 17. Examples 86 to 88 Using the inorganic oxide used in Example 82, U-4HMA, U-4TMA, U
A paste-like composite material was prepared in the same manner as in Example 82, except that -4BMA, tetramethylolmethane triacrylate (hereinafter referred to as TMMT), and methyl methacrylate (hereinafter referred to as MMA) were used. The mixing ratio of vinyl monomer components is shown in the table below.
As shown in 18. The paste-like composite material was further cured in the same manner as in Example 82, and the physical properties of the composite resin were measured. The results are also shown in Table 18. Example 89 Dissolve 0.36 g of PdCl ₂ in 1N aqueous hydrochloric acid solution, and add 10 g of inorganic oxide synthesized in the same manner as in Example 1 (calcined at 500°C for 2 hours, surface area 110 m ² /g) to this aqueous solution. was impregnated, evaporated to dryness at 80 to 85°C, and dried overnight at 110°C to obtain a powder. After molding this powder with a pelletizer, it was filled into a Pyrex reaction tube with an inner diameter of 28 mm and heated at 350°C under a hydrogen atmosphere.
It lasted about 3 hours. Then the temperature of the reaction tube was set to 200
℃, hydrogen 1.0/h, carbon monoxide 0.5/h
After 20 hours, the composition at the outlet of the reaction tube was analyzed by gas chromatography.
As a result, methanol was produced. The yield was 0.06 mol% based on the carbon monoxide supplied. This was a high activity equivalent to about 10% of the equilibrium yield calculated from thermodynamic data.

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Claims (1)

[Claims] 1. Silica and at least two metal oxides selected from the group consisting of oxides of metals of Groups 1, 2, 3, and 3 of the periodic table that can be combined with silica. The main constituents have a specific surface area of 100m ² /
An inorganic oxide having a weight of at least g and a spherical shape. 2 The main constituents (silica /Group oxide of the periodic table/an inorganic oxide that is a constituent component of titanium (excluding crystalline ones), has a specific surface area of 100 m ² /g or less, and has a spherical shape. 3. A mixture comprising a hydrolyzable organosilicon compound and at least two metal compounds selected from the group consisting of hydrolyzable compounds of Groups 1, 2, 3, and 3 of the Periodic Table of Metals. The solution is added to an alkaline solvent in which the organosilicon compound and the compounds of Groups 1, 2, 3, and 3 of the Periodic Table of Metals are dissolved, but the reaction products are not substantially dissolved, and the hydrolysis is carried out. Group 3 of the periodic table, characterized in that the reaction product is precipitated.
A method for producing an inorganic oxide whose main constituents are silica and at least two metal oxides selected from the group consisting of group oxides and oxides of group metals. 4. A mixture containing a hydrolyzable organosilicon compound and at least two metal compounds selected from the group consisting of hydrolyzable compounds of Groups 1, 2, 3, and 3 of the Periodic Table of Metals. The solution is added to an alkaline solvent in which the organosilicon compound and the compounds of Groups 1, 2, 3, and 3 of the Periodic Table of Metals are dissolved, but the reaction products are not substantially dissolved, and the hydrolysis is carried out. of metals of Groups 1, 2, and 3 of the periodic table, characterized in that the reaction product is precipitated, and then a hydrolyzable organosilicon compound is added to the reaction system for hydrolysis. A method for producing an inorganic oxide whose main components are at least two metal oxides selected from the group consisting of oxides and silica. 5 A polymerizable vinyl monomer, at least two metal compounds selected from the group consisting of compounds of metals of Groups 1, 2, 3, and 3 of the periodic table that can be bonded to silica, and silica. A composite material characterized by consisting of a spherical inorganic oxide as a constituent component.