JP2003176120A - Method for producing silica-titania composite oxide - Google Patents

Abstract

(57) [Problem] To provide a novel method for producing a silica-titania composite oxide in which microcrystals of rutile titania are dispersed. SOLUTION: A co-hydrolyzate obtained by hydrolyzing a silicon alkoxide compound such as silicon tetramethoxide and silicon tetraethoxide and a titanium alkoxide compound such as titanium tetraethoxide and titanium tetraisopropoxide is converted into nitrogen. By heating at 900 to 1300 ° C. under a non-oxidizing atmosphere such as under argon or the like to form a composite oxide, microcrystals of rutile-type titania are precipitated in the composite oxide, A silica-titania composite oxide dispersed in a crystalline matrix is obtained.

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical semiconductor
Suitable for composite resin filler such as dental composite resin
The present invention relates to a method for producing a composite oxide. [0002] Composite oxides composed of silica and titania
(Hereinafter abbreviated as composite oxide) has a coefficient of thermal expansion of zero
Or when showing a negative value or changing the content of titania
Excellent in that fine adjustment of the refractive index is possible
However, complex oxidation occurs when titania separates phases.
Since the material becomes cloudy, there is a contrivance in the manufacturing method. Therefore
Since then, synthesis has been attempted by various methods. [0003] For example, a solution using silica and titania as raw materials
1750 using silicon and titanium chloride as raw materials
Flame hydrolysis method (PCS
chultz, Journal of The Amer
ican Ceramic Society, Volume 59, 2
14 page, 1976), silicon and titanium
Sol-gel method using lucoxide compound (Kanichi Kamiya, product
S. Hana, Journal of the Chemical Society of Japan, No. 10, 1571 pages,
1981). In the melting method, silica and titania are generally melted.
The problem is that the phase is easily separated because the material is heated to the melting temperature.
You. Titania in composite oxide crystallizes in rutile form
However, spherical particles cannot be obtained by this method. Flame
In the hydrolysis method, the obtained amorphous composite oxide is
When reheated, titania crystallizes in rutile form.
The method yields only membranes and aggregates, but not spherical particles.
I can't. On the other hand, in the sol-gel method, depending on the manufacturing method,
Gives spherical particles, but the titania in the composite oxide is
What is amorphous when heated will crystallize into anatase type
I do. In this method, rutile crystallized
There is no. More specifically, a composite oxide sphere is described.
Particles are described in Japanese Patent Publication No. 1-38043. This
In the case of heat treatment of the spherical particles, the particles
Some of the titania in the product crystallizes in anatase form
However, an example of crystallization to rutile type is not disclosed. Also,
Japanese Patent Application Laid-Open No. 2-153816
Mixture of tandem alkoxide compounds into flame
In the method for producing spherical composite oxide particles,
The resulting particles are amorphous. Similarly, crushed particles of composite oxide
Japanese Patent Application Laid-Open Nos. 3-232730 and 3-23
2741: Alkoxide compound of silicon and titanium
A method for obtaining composite oxide particles from a raw material is disclosed.
However, the titania in these particles is
It is described that it crystallizes into a natase form. [0006] The titania in the composite oxide is usually as described above.
It is known that there are two types of crystals. Rutile and
Comparing the refractive indices of two types of anatase type crystals,
For natase type, nω = 2.5612, nε = 2.488
0, whereas the rutile type has nω = 2.612.
4, nε = 2.8993, and the rutile type is higher. SUMMARY OF THE INVENTION A sealing material for optical semiconductors
Is transparent to transmit light generated by semiconductor
However, dental composite resins also contain natural teeth
The same translucency as is required respectively. for that reason
Is used for composite resins such as sealing materials and composite resins
The refractive index of the filler matches that of each resin, or
Must be close. That is, it has a specific refractive index
Particles are required. [0008] Complex oxide particles having a specific refractive index are prepared.
To manufacture, titania with a higher refractive index than silica
Compounded with Rica, in this case the crystal structure of titania
Rutile-type structure is more amorphous or anatase-type structure
This is effective because the refractive index is high. Further, the content of titania in the composite oxide particles
If the amount is large, the crystals of titania precipitated by heating will be large.
And the transparency of the particles tends to decrease. Yo
To minimize the content of titania in the composite oxide particles.
It is necessary to improve the refractive index under few conditions. That
For example, the crystal structure of titania in the composite oxide particles is amorphous
Rutile-type structure is more desirable than quality structure and anatase-type structure
Good. The composite oxide particles are based on silica and titania.
When produced by the melting method, the titania separates and becomes cloudy.
It is easy to crush and separate even if a transparent body is formed by the melting method.
Classification process is required and impurities are easily mixed.
It is preferable to employ a sol-gel method using a metal as a raw material.
However, the composite oxide obtained by the sol-gel method is as described above.
As described above, the titania contained in this material has an amorphous structure or
The only known type is the rutase type structure.
Was not known. Means for Solving the Problems To solve the above problems
In addition, as a result of intensive studies, silica prepared by the sol-gel method
-Heat treatment of titania co-hydrolysate under specific conditions
Therefore, the titanium in the obtained silica-titania composite oxide is obtained.
It was found that tania crystallized in rutile form, and the present invention
Was completed. That is, the present invention mainly comprises silica and titania.
Spherical particles having an average particle diameter of 0.05 to 50 μm as a constituent component
Particles, and the percentage of rutile-type crystal titania in total titania
The composite oxide particles are at least 5 mol%
I am a child. Another invention is a silicon alkoxide compound.
And hydrolysis of titanium alkoxide compound
The co-hydrolysate obtained in a non-oxidizing atmosphere at 900 ° C.
Rutile-type crystal h characterized by heating at 1300 ° C.
Method for producing silica-titania composite oxide particles containing tania
Is the law. BEST MODE FOR CARRYING OUT THE INVENTION The composite oxide particles of the present invention
Average particle size of mosquito and titania as basic components is 0.05 to
50 μm spherical particles, at least a part of titania
Contains rutile-type crystals (hereinafter referred to as silica-titania compound).
Oxide oxide particles). Other titania is amorphous
Structure or other crystal structure, such as anatase-type structure.
May be. Content of the rutile-type crystal titania in titania
The proportion needs to be 5 mol% or more. Rutile crystal titania
Is less than 5 mol%, the silica-titania composite oxide
The refractive index of the particles cannot be improved more effectively
No. For examining the content of rutile crystal titania
Is the rutile crystal titer measured by the powder X-ray diffraction method.
Measure the peak intensity of the near (110) plane diffraction peak
It can be calculated from a separately prepared calibration curve. Inspection
To create a dose curve, a 100% rutile crystallized ru
Mix chill-type titania and amorphous silica in any proportion
The obtained sample was measured in the same manner as above, and
What is necessary is just to obtain the relationship between the content of tania and the peak intensity. [0015] The silica-titania composite oxide particles contained
Crystallized rutile and anatase titania crystals
The size of is not particularly limited, but may be small depending on the application.
It is more preferable. For example, the silica-titania composite acid of the present invention
For optical semiconductors that require high light transmittance of halide particles
When used as filler material, crystallized titania particles
The diameter is 100 nm or less, preferably 50 nm or less,
Preferably, the thickness is 20 nm or less. Crystallization
Of the size of the titania crystals observed with a transmission electron microscope
And the half value of the diffraction peak of powder X-ray diffraction
It can also be calculated from the width. Titania which is one of the constituents of the particles
Is in a state chemically bonded to silica or in silica
It exists in a dispersed state as microcrystals, and silica and
Titania cannot be physically separated. Both components
Existing in such a state may be in the infrared spectrum or
By measuring the refractive index or observing transmission electron microscope images
Can be confirmed. For example, in the infrared spectrum
950nm ^-1 Specific absorption near
And the refractive index of the silica-titania composite oxide particles is
It is between the refractive indices of both components, and the content of titania is
As it increases, the refractive index also increases. Also, transmission electron
Observation of the microscope image reveals that the amorphous silica-titania
Or microcrystals of titania in an amorphous silica matrix
It can be checked whether the state is dispersed. The silica-titania composite oxide particles of the present invention
The content of titania contained in the mixture is preferably 3 mol% or less.
50 mol% or less, more preferably 3 mol% or more and 30 mol
% Is desirable. Titania formulation
If the rate is small, titania crystallizes even when heated at high temperatures
The silica-titania composite oxide particles of the present invention
You may not be able to get a child. On the other hand,
If the compounding ratio is too high, generally use spherical particles
And heating at high temperatures can cause titania to form.
Transparency is impaired because the crystals become too large,
It tends to be unusable as a filler for high composite resins
is there. The silica-titania composite oxide particles of the present invention
Has an average particle diameter in the range of 0.05 to 50 μm. flat
If the average particle size is less than 0.05 μm, the particles are likely to aggregate,
When filling the composite resin, there is a problem such as poor operability.
Condition occurs. When the average particle size exceeds 50 μm
Is a problem that transparency cannot be maintained when using a composite resin
There is. Dental composites that require surface lubricity
When the particles of the present invention are used in the resin, the average particles
The diameter is preferably 10 μm or less, more preferably 1 μm or less.
No. In addition, encapsulation for optical semiconductors that require high light transmission
When used as a filler for materials, the average particle size is 10μ
m or less, more preferably 1 μm or less. The silica-titania composite oxidation of the present invention
The shape of the object particles is spherical. Crushed particles that are not spherical in shape
When kneading irregular shaped particles such as
If problems such as high height or poor surface lubricity occur
There is a case. It is also used as a transparent encapsulant for encapsulating optical semiconductors.
Prefer spherical particles so as not to damage the semiconductor element
You. Composition of Silica-Titania Composite Oxide Particles
Means X-ray fluorescence analysis, ICP analysis, atomic absorption analysis, chemical
It can be clarified by a known method such as precipitation. Of particles
To observe the average particle size and shape, use a scanning electron microscope or transmission
A method using an electron microscope such as a scanning electron microscope is suitable.
Also, use a particle size distribution analyzer to measure the average particle size of the particles.
Can be used. The silica-titania composite oxide particles are as follows:
Typically, it can be manufactured by the manufacturing method described below.
it can. That is, silicon alkoxide compound and titanium
Obtained by hydrolyzing a mixture with a
Spherical addition of silicon and titanium as main constituents
900 ° C. to 1300 under non-oxidizing atmosphere
Manufactured by heating at ℃. [0022] This manufacturing method is based on the rutile crystal titer.
Production of silica-titania composite oxide particles containing near
Not only, plate-like, rod-like, also containing rutile crystal titania,
Applicable to the production of amorphous silica-titania composite oxide
You. Therefore, the rutile crystal is not limited to the following shape.
Silica-titania composite oxide containing titania (hereinafter simply referred to as
Is called a silica-titania composite oxide).
Will be explained. As the silicon alkoxide compound,
General formula Si (OR) ₄ Or SiR _n (OR ') _4-n [N
Is an integer of 1 to 3].
It can be adopted without. Such compounds, for example,
For example, silicon tetraethoxide, silicon tetramethoxide
Sid, silicon tetrapropoxide, methyltrimethoxy
Sisilane, methyltriethoxysilane, ethyltrimeth
Xysilane, ethyltriethoxysilane, etc.
You. Silicon Al when n is 1 or 2 in the above general formula
Cooxide compounds are usually trialcohols as exemplified above.
Silicon alkoxidation of xy or tetraalkoxy type
It is used by partially mixing with the compound. As the titanium alkoxide compound,
Titanium Al having a hydrolyzable alkoxide group
Cooxide compounds can be widely used. For example, titanium
Traethoxide, titanium tetraisopropoxide,
Titanium tetrabutoxide and the like are preferably employed. Silicon alkoxide compound and titanium
By hydrolyzing the mixture with the alkoxide compound
To obtain a co-hydrolysate.
By heating at a temperature of 0 ° C. or more, silica-titani
A) Converted to composite oxide. In the production of silica-titania composite oxide
Before the hydrolysis, co-condensation of both alkoxide compounds
Preferably, it is a low condensate. Silicon alkoxide
The compound and the titanium alkoxide compound are generally
Mixtures where both compounds are not condensed due to different rates of water splitting
When the compound is hydrolyzed, silica and titania particles
They may be generated independently. To obtain a low condensate of both compounds, a known method
The method can be adopted without any particular limitation.
Titanium hydrolyzate of titanium alkoxide compound
The method of adding a lucoxide compound is preferably adopted.
You. The solvent used for the low condensate solution is a low condensate
Can be used without particular limitation as long as it dissolves
Generally because of reactivity, operability, easy availability, etc.
Means methanol, ethanol, isopropanol, pig
Knol, ethylene glycol, propylene glycol, etc.
Are preferred. Also, diethyl ether
Such as ethers and esters such as ethyl acetate and methyl acetate
Like hydrocarbons such as benzene, toluene, hexane, etc.
Some organic solvents can be used as a mixture. To hydrolyze the low-condensate, a known method is used.
The method can be widely used, but in acidic or alkaline solutions.
A hydrolysis method is preferably employed. The hydrolyzate of the low condensate is a spherical particle
When obtaining a low-condensation product,
Hydrolysis in a potash solution is preferred. alkalinity
Any known organic solvent is limited as the solvent for the solution.
Can be used without. Solvents generally preferably used are those described above.
The same alcohol as described as the solvent for the low condensate
Or ethers, esters, hydrocarbons, etc.
Mixed solvent obtained by partially adding organic solvent to the alcohols and water
And a water-containing solvent. Alkaline solution
Sodium hydroxide, potassium hydroxide
Well-known such as trimethylamine, triethylamine, etc.
Lucari compounds can be used, but ammonia is particularly preferred.
is there. The particle size of the spherical co-hydrolyzate particles is as follows:
Alkaline concentration, water concentration, organic solution
Since it is affected by factors such as the type of medium,
It is preferable to determine these conditions. Generally, before
The alkaline concentration of the alkaline solution is 1.0 to 10 mol /
Preferably in the range of liters, alkali concentration
The higher the particle size of the resulting spherical co-hydrolysate particles
It tends to be larger. The concentration of water in alkaline solutions
The degree is generally in the range of 0.5 to 50 mol / l
It is preferable to choose from them. Organic solution in the alkaline solution
As for the type of the medium, generally, alcohol used for the solvent is used.
When the number of carbon atoms in the class increases, the spherical silica
Tania composite oxide particles tend to increase in particle size
You. The solution of the low condensate is added to an alkaline solution.
The method of adding is not particularly limited, but is generally in small amounts.
It is preferable to add over a long period of time, usually from several minutes to 10 minutes.
It may be performed within a few hours. The solution of the low condensate
During addition to the potash solution, the temperature of the alkaline solution will
Differs depending on various conditions and cannot be limited
However, it may be usually carried out in the range of 0 ° C to 50 ° C. Further
During the addition of the low-condensate solution to the alkaline solution,
Lucari solution is used for magnetic stirrer, stir bar, etc.
Therefore, it is necessary to constantly stir. The spherical co-hydrolysis produced by the above operation
The pulverized particles may be dried after separation. Obtained in this way
Spherical co-hydrolysate particles have a narrow particle size distribution range
Are particles of the co-hydrolysate. On the other hand, when the shape of the co-hydrolysate is other than spherical,
In the case, the low-condensation product in an acidic or alkaline aqueous solution
A known method of hydrolysis is preferably employed. example
For example, an acidic aqueous solution and the above low-condensate are mixed, stirred, and hydrated.
By decomposing, complex
It is known that a lump of composite oxide is obtained.
Bulk material or amorphous particles obtained by grinding a bulk material,
Alternatively, the low-condensation product is thinly coated on a polymer film.
And hydrolyzed solids in the presence of steam.
Scale-like co-hydrolysates obtained by peeling off shaped objects
As with the spherical co-hydrolysate particles, silica-titania
It can be used as a raw material for producing a composite oxide. The spherical co-hydrolysis obtained as described above
Particles or other forms of co-hydrolysate in a non-oxidizing atmosphere
Each shape by heating at 900-1300 ℃ below
Is obtained. The heating temperature is lower than 900 ° C.
Then the titania does not crystallize or the crystallinity is
Extremely low. Heat at a temperature higher than 1300 ° C
And the titania crystal grows larger and silica-titania composite
Reduced oxide transparency or amorphous silica
Crystallized into cristobalite crystals from
The coloring of the silica-titania composite oxide itself becomes strong
Is not preferred. In particular, if the co-hydrolysate is spherical or
If the particles are of other shapes, the particles will be easy to sinter.
This is not preferred because of the tendency to occur. Further, the silica-titania composite oxide has a particle size of 1 μm.
m or less silica-titania composite oxide particles,
The higher the temperature, the easier it is for particles to sinter.
Therefore, it is preferably 1200 ° C. or lower, more preferably 11 ° C.
It is desirable to heat at a temperature of 00 ° C. or less. However, the above particles
Is dispersed in a gas phase at a temperature exceeding 1200 ° C.
No sintering if fed and heated. Time required for heating
Depends on the size and atmosphere of the particles.
Although it cannot be determined, 1 to 20 hours is appropriate. By the way, the co-hydrolysate is placed in a non-oxidizing atmosphere.
Silica-titania even when heated below 900 ° C
When the titania content in the composite oxide is low,
If chill-type titania crystals cannot be confirmed or
In some cases, it can be recognized, but very small. A place like this
In this case, the composite oxide is further subjected to a non-oxidizing atmosphere such as in air.
By reheating in an atmosphere other than the atmosphere,
It is possible to increase the content of chill-type titania crystals
it can. This phenomenon is caused by heating in a non-oxidizing atmosphere.
Sometimes rutile-type structures that cannot be measured by X-ray diffraction, etc.
Microcrystals have already been formed and
It is thought that they grew. Therefore, according to the present invention, in a non-oxidizing atmosphere,
After heating at 900-1300 ° C, further under oxidizing atmosphere
To form rutile-type titania crystals.
An embodiment of increasing the length is also preferably employed. Note that this
In this case, since heating is performed in an oxidizing atmosphere,
With the growth of the near crystal, a new anatase-type titani
Since crystals often occur, the rutile structure and the
-Silica mixed with two types of titania crystals having a structure of type
Often becomes a titania composite oxide. The silica-titania composite oxide of the present invention was produced
Atmosphere to heat the co-hydrolysate
Co-hydrolysates, which are essential to keep
It becomes a silica-titania composite oxide by heat. Heating
Use an oxidizing gas atmosphere such as air or oxygen as the atmosphere.
When used, titania in the co-hydrolysate becomes anatase type
Crystallizes and does not become rutile. The non-oxidizing atmosphere is used for heating.
To be able to keep the non-oxidizing atmosphere in the electric furnace
If it is, there is no particular limitation. For example, electricity used for heating
Nitrogen, argon, helium, hydrogen, carbon monoxide in the furnace
Non-acid by using one or two kinds of gases such as oxygen and carbon dioxide
It is preferable to maintain a oxidizing gas atmosphere or a vacuum.
Suitable. Further, in order to positively prevent oxidation,
Pre-coating the surface of the hydrolyzate with an organic compound
More preferred. Co-hydrolyzate surface coated with organic compound
In this case, known organic compounds are widely used.
Can be used, but can reliably cover the surface of the co-hydrolysate,
What is hard to volatilize is preferable. With something like this
Polyethylene glycol, polystyrene, polya
A polymer soluble in any solvent such as crylic acid is preferable,
Among them, polyethylene glycol and water that are soluble in alcohol
Polyacrylic acid which is easily soluble in water is preferred. When the organic compound is coated on the co-hydrolysate,
Is, for example, polyethylene glycol to co-hydrolysate
After adding the alcohol solution and mixing well, dry the solvent
Is adopted. The co-hydrolysate coated with the above organic compound is
When heated in a non-oxidizing atmosphere, carbides of organic compounds
May remain on the surface or inside of the particles and turn grayish white
is there. In such cases, these co-hydrolysates are emptied.
Heat again in an oxidizing atmosphere such as gas to oxidize and remove carbides.
Leaving a white silica-titania composite oxide
It can be. The silica obtained by heating the co-hydrolysate
Under the conditions described above, the titania in the carbon-titania composite oxide
The mechanism of selective rutile crystallization during heat treatment is clear
However, it is considered as follows. Alkoxide
Silicon and titanium synthesized using compounds as starting materials
Is heated in a non-oxidizing atmosphere
Then, the starting material titanium alkoxide compound
Produced by hydrolysis of silicon and silicon alkoxide compounds
Organic compounds or contained in co-hydrolysates
Organic solvents or residues of alkoxy groups in a non-oxidizing atmosphere
Due to thermal decomposition, the surroundings of the co-hydrolysate are strong
It is kept in a reducing atmosphere. For this reason, co-hydrolysates or
Indicates that the charge of titanium and the coordination number of oxygen in the composite oxide are very small.
Strange change, transition of titania to selective rutile-type structure
Is likely to be happening. Titania single component system
Then, irreversible transition from anatase type to rutile type
It is known that oxygen ion vacancies in titania
It is said to promote nucleation. However,
In the Ming system, titania in the complex oxide forms the anatase form.
To the rutile form via
Without the amorphous titania passing through the anatase form
It is thought that it was crystallized in rutile form. Next, the present invention will be described more specifically with reference to examples.
As will be described, the present invention is limited by the following examples.
is not. Silica-titania composite used in the following examples
Unless otherwise specified, the properties of the composite oxide particles were measured as follows.
Was measured as described above. (1) Average particle size: determined from an image taken by a scanning electron microscope
Was. (2) Refractive index of particles: various kinds of sample particles having different refractive indexes
Suspend the solution at 25 ° C.
The refractive index was measured with an Abbe refractometer. (3) Identification of crystal: The crystal structure of titania was identified by X-ray
This was performed by a powder method using a diffractometer. (4) Ratio of rutile crystal titania: rutile crystal titania
Near (Kanto Chemical Co., Ltd., reagent grade) and amorphous silica
Make a sample mixed at a desired ratio and use a powder X-ray diffractometer
Of the diffraction peak of the (110) plane of rutile titania
The minute strength was measured. Against the content of rutile type crystal titania
To plot a calibration curve
Was. Using the same measurement conditions as above,
X-ray diffraction was measured and the rutile crystal titer was determined from the above calibration curve.
The near content was calculated. Total titania content (mol%)
Of the content (mol%) of the rutile-type crystal titania with respect to
Percentage is defined as the ratio (mol%) of rutile-type crystalline titania
did. Production Example 1 Synthesis of Cohydrolyzate Particles (A): Inner Volume with Stirring Blade
140 g of methanol in a 4 liter glass reaction vessel,
260 g of isopropanol and aqueous ammonia (25
% By weight) to prepare a reaction solution.
The mixture was stirred while maintaining the temperature at 40 ° C. Next, in a 3 liter Erlenmeyer flask,
Contetramethoxide (Si (OMe) _Four , Colcoat
Co., Ltd., trade name: methyl silicate 39) 799 g
288 g of methanol and 0.1 wt.
% Hydrochloric acid aqueous solution (35% hydrochloric acid, Wako Pure Chemical Industries, Ltd.
(Diluted with water to 1000) 41 g and stirred for about 10 minutes
Was. Subsequently, titanium tetraisopropoxide (Ti
(Oi-Pr) _Four , Nippon Soda Co., Ltd., Product name: A-1
(TPT)) Dilute 213 g with 450 g of isopropanol.
The diluted solution is added, and a clear homogeneous solution (silicon tetraal
Co-condensate of cooxide and titanium tetraalkoxide)
Got. 1792 g of the above homogeneous solution and aqueous ammonia
(25% by weight) 480 g of each was initially added to the reaction solution.
Reduces the dropping speed and gradually increases it toward the end.
Thus, the mixture was dropped simultaneously over 8 hours. After dropping,
The obtained co-hydrolyzate was filtered and dried at 150 ° C.
Filtration yielded about 370 g of co-hydrolysate. Obtained co
When the hydrolyzate was observed with a scanning electron microscope, the average
Extremely monodisperse spherical particles with a particle diameter of 0.40 μm
[Hereinafter referred to as particles (A)]. In the particles (A)
Of the titania compounding ratio [Ti / (Ti + Si)]
It was 12.5 mol% from the composition. Production Example 2 Synthesis of Co-Hydrolysate Particles (B): Internal Volume with Stirring Blade
80 g of methanol was placed in a 4 liter glass reaction vessel.
320 g of sopropanol and ammonia water (25
%), A reaction solution was prepared, and the temperature of the reaction solution was adjusted.
The mixture was stirred while maintaining the temperature at 40 ° C. Next, in a 3 liter Erlenmeyer flask,
Contetramethoxide (Si (OMe) _Four , Colcoat
(Product name: methyl silicate 39) 868 g
While stirring, 115 g of methanol and 0.1 weight
% Hydrochloric acid aqueous solution (35% hydrochloric acid, Wako Pure Chemical Industries, Ltd.
16 g) (diluted with water to 1000) and stir for about 10 minutes.
Was. Subsequently, titanium tetraisopropoxide (Ti
(Oi-Pr) _Four , Nippon Soda Co., Ltd., Product name: A-1
(TPT) 85g diluted with 180g isopropanol
And add a transparent homogeneous solution (silicon tetra alcohol)
Co-condensate of oxide and titanium tetraalkoxide)
Obtained. 1265 g of the above homogeneous solution and ammonia water
(25% by weight) 480 g of each was initially added to the reaction solution.
Reduces the dropping speed and gradually increases it toward the end.
Thus, the mixture was dropped simultaneously over 8 hours. After dropping,
The obtained co-hydrolyzate was filtered and dried at 150 ° C.
Filtration yielded about 365 g of co-hydrolysate. Obtained co
When the hydrolyzate was observed with a scanning electron microscope, the average
Extremely monodisperse spherical particles with a particle diameter of 0.54 μm
[Hereinafter referred to as particles (B)]. In the particles (B)
Of the titania compounding ratio [Ti / (Ti + Si)]
It was 5.0 mol% from the composition. Production Example 3 Synthesis of Co-Hydrolysate Particles (C): Internal Volume with Stirring Blade
Isopropanol 35 in a 4 liter glass reaction vessel
0 g and 150 g of aqueous ammonia (25% by weight).
To prepare a reaction solution and maintain the temperature of the reaction solution at 40 ° C.
While stirring. Next, in a 5 liter Erlenmeyer flask,
Contetramethoxide (Si (OMe) _Four , Colcoat
(Product name: methyl silicate 39) 1585 g
While charging and stirring, 611 g of methanol and 0.1 weight
% Hydrochloric acid aqueous solution (35% hydrochloric acid, 1% by Wako Pure Chemical Industries, Ltd.)
86 g), and stirred for about 10 minutes
did. Subsequently, titanium tetrabutoxide (Ti (O
-Bu) _Four , Nippon Soda Co., Ltd., product name; B-1 (TB
T)) 541 g was diluted with 960 g of isopropanol
Add the solution and add a clear homogeneous solution (silicon tetraalkoxy).
And titanium tetraalkoxide).
Was. Subsequently, the homogeneous solution and aqueous ammonia (2
5% by weight) were simultaneously added dropwise to the reaction solution.
However, for 5 hours after starting the dropping, the reaction solution
The tip of the tube is fixed to the surface, increasing by dripping
By pumping the reaction solution
Particles so that the volume of the reaction solution does not substantially change.
Done. After 5 hours from the start of dropping, pump the reaction solution.
The bleeding was stopped and dripping was continued up to 10 hours. End of dripping
After completion, the obtained co-hydrolysate is filtered and dried at 150 ° C.
As a result, about 430 g of a co-hydrolysate was obtained. Profit
The co-hydrolysate was observed with a scanning electron microscope.
And spherical particles having an average particle diameter of 1.62 μm [hereinafter, particles
(C). Of titania in the particles (C)
The mixing ratio [Ti / (Ti + Si)] is 1
3.25 mol%. Production Example 4 Synthesis of Cohydrolyzate Particles (D):
Silicon tetramethoxide (Si (OMe))
_Four , Colcoat Co., Ltd., trade name: methyl silicate 3
9) Charge 1681 g, and stir methanol 22
1 g and 0.1% by weight aqueous hydrochloric acid solution (35% hydrochloric acid, Wako Pure Chemical Industries, Ltd.)
(Industrial Co., Ltd. diluted with water to 1/1000)
And stirred for 10 minutes. Then, titanium tetraiso
Propoxide (Ti (Oi-Pr) _Four , Nippon Soda
(A-1 (TPT)) (490 g).
Clear homogeneous solution (silicon tetraalkoxide and titanium
(A co-condensate of methtetraalkoxide). The above solution
Cool with ice while stirring, and when sufficiently cooled, cool with ice
795 g of ion-exchanged water was added. Stir for about 10 minutes
After that, when left indoors, the contents gelled and became cold
It solidified in a heavenly state. Next, a pinhole with an inner diameter of about 1 mm
Open the lid and close at 12:00 in a thermostat kept at 95 ° C.
Left for a while. Add 300 g of ion-exchanged water and add 12
After holding at 0 ° C for 5 hours, open the lid and dry overnight.
After all, a transparent glass block of small finger size was obtained. The above glass lump
Is roughly pulverized with a ball mill, and then jet-milled.
5.5 nozzle pressure by FS-4) manufactured by Seishin Enterprise
kg / cm ^Two And crushed. Scan the co-hydrolysate after grinding
When observed with a scanning electron microscope, the particle size was 1 μm to 8 μm.
In the range of μm, the particle shape is irregular co-hydrolysate
Below, referred to as particles (D)]. H in the particles (D)
Tania compounding ratio [Ti / (Ti + Si)] is the charge composition
Was 13.5 mol%. Examples 1 to 7 The particles of each of the cohydrolysates of Production Examples 1 to 4 were subjected to the conditions shown in
To obtain silica-titania composite oxide particles. This
Table 1 also shows these physical properties. In addition, each co-hydrolyzate particle
Firing of the child was performed according to the method described below. Polyethylene glycol having a molecular weight of 20,000 (sum
5g and 25g of methanol while heating
Dissolve to prepare a clear solution. Co-hydrolysate particles 25
g and the above solution in a mortar, then slowly add methanol
And evaporate the co-hydrolysate particles with polyethylene glycol.
A dry mixture of coal was obtained. The above mixture in a crucible
The mixture is charged into an electric furnace, and
Heated at temperature for predetermined time. At this point, the normal grain
The child was light gray, but the gray component was polyethylene
The glycol was carbonized. Continue to blow air
While heating at 800 ° C for 2 hours to burn the carbides
Color composite oxide particles were obtained. Example 8 Example 1 except that heating was performed at 900 ° C. for 2 hours in a nitrogen atmosphere.
As above, silica-titania composite oxide particles were obtained.
The physical properties of the particles were measured in the same manner as in Example 1.
Filter, average particle size is 0.36 μm, rutile crystal titania
Was 1 mol%. Next, the above silica-titani
(A) A part of the composite oxide particles is in air at 1200 ° C. for 6 hours.
When heated, the average particle size is 0.35 μm and the refractive index is
1.547, crystal structure is rutile with anatase type structure
A peak of the type structure was detected. Rutile crystal at this time
The titania content was 5 mol%. Comparative Examples 1 to 3 Each co-hydrolyzate particle is shown in Table 1 according to Examples 1 to 7.
To obtain silica-titania composite oxide particles.
Was. Table 1 shows these physical properties. [Table 1] According to the present invention, there is provided a method for manufacturing a semiconductor device according to the present invention.
In the composite oxide, titania in the composite oxide has a higher refractive index.
Because of the rutile-type structure, conventionally known anaters
Reduces titania content compared to zeolite-type composite oxide
be able to. For this reason, regarding the production of composite oxides,
Indicates that the use of titanium alkoxide compounds is
And spherical silica-titania composite oxide particles
With regard to spherical silica-tita having a low titania content,
It has become possible to provide near composite oxide particles. The composite oxide of the present invention can adjust the refractive index arbitrarily.
Can be adjusted so that encapsulants for optical semiconductors and dental composites
Composite resin fillers that need to transmit light such as resin
Useful as In addition, a rutile type connection that was not available before
Silica-titania complex acid containing microcrystalline titania
Can be expected as a new catalyst or catalyst support
You.

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Claims (1)

Claims 1. A co-hydrolyzate obtained by hydrolyzing a silicon alkoxide compound and a titanium alkoxide compound is heated at 900 ° C to 1300 ° C in a non-oxidizing atmosphere to form a rutile crystal. A method for producing a silica-titania composite oxide in which microcrystals of rutile crystalline titania are present in a state of being dispersed in an amorphous matrix, wherein titania is precipitated.