JP2820251B2 - Titanium oxide sol - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [0001] The present invention relates to a titanium oxide sol,
More specifically, it has a specific shape and
And a titanium oxide sol comprising dispersed particles. [0002] TECHNICAL BACKGROUND OF THE INVENTION AND PROBLEMS THEREOF
Tan particles are expanding their applications utilizing their chemical properties
There are two. Titanium oxide, for example, has a suitable bond with oxygen
As well as oxidation resistance,
Or use the blocking power of ultraviolet rays
Used as a cosmetic material or plastic surface coating material
Or use an anti-reflective coating material by using a high refractive index.
Or use these effects in combination
It is used as a functional hard coat material. As described above, titanium oxide is used for many purposes.
In any case, titanium oxide
Requires many functions. For example, oxidation as a catalyst
When using titanium, not only the activity for the main reaction
Good, selectivity, mechanical strength, heat resistance, acid resistance or durability
Properties are required, and titanium oxide is used as a cosmetic material
In case, not only the UV shielding effect, but also smoothness, skin
Texture and transparency are required. Further coating materials
When using titanium oxide as the material, transparency, high refractive index
In addition to excellent film formation, adhesion, and film hardness
Degree, mechanical strength, wear resistance, etc. are required. As described above, titanium oxide particles are used for various purposes.
To use, the titanium oxide particles are
Are required to have various characteristics.
Even when used for applications, ultra fine particles are preferred.
No. Moreover, when transparency is required for titanium oxide particles
Means that the particles have the same shape and size
Rather, it must be highly dispersed in the medium during formulation.
You. Manufacture titanium oxide particles that meet these characteristics
To do this, use highly dispersed colloidal titanium oxide (titanium oxide
Is particularly preferable. A method for producing such a titanium oxide sol is described as follows.
In the past, meta-
The gel obtained by washing after neutralizing titanic acid is peptized with acid.
Or a titanium salt aqueous solution
The sol is deionized by ion exchange resin, etc.
There are known methods for obtaining them. However, the above-mentioned titanium oxide
The manufacturing method of the metal has the following problems. The dispersed particles of the sol are spherical or pseudo spherical aggregates
And the particle size is not uniform, resulting in cloudiness and poor transparency.
You. The particle size is small depending on the sol formation conditions
Although it is possible to obtain sols with excellent transparency,
In that case, a large amount of acid is required as a stabilizer. The sol is stable only in the acidic region (pH 3 or less) and is neutral
Or alkalinity causes precipitation or gelation.
Therefore, the range of use is limited. Mixing sol with organic solvent such as alcohol
Or the solvent is replaced with an organic solvent,
Deposits on the surface of plastic, etc.
Hard to use as a hard coat agent. The sol particles are spherical or pseudospherical
Therefore, for example, it was mixed with the base resin and used as a coating film.
In this case, the titanium oxide particles in the coating film do not exist
Voids remain between the particles and the density cannot be increased.
And the film properties or film strength are inferior. [0010] SUMMARY OF THE INVENTION The present inventors have solved the above problems.
After intensive research, we decided to oxidize by a specific method.
If titanium sol is manufactured, conventional titanium oxide sol
Specified shape and uniform size that could not be obtained by the method
Titanium oxide formed by dispersing titanium oxide particles in a dispersion medium
Sol obtained from the titanium oxide sol
Titanium particles are found to have various excellent properties
Thus, the present invention has been completed. [0011] SUMMARY OF THE INVENTION The titanium oxide sol according to the present invention comprises
The length L of the long axis is 4 to 500 mμ, and the length D of the short axis is
Titanium oxide particles having a particle size of 4 to 100 μm
And the average value of the ratio L / D of L and D is [L / D]_A
Where (1 ± 0.3) × [L / D]_AAll in the range
A titanium oxide sol in which more than 60% of the particles are present,
TiO_Two37 when the concentration is adjusted to 0.005% by weight.
When the light transmittance in the wavelength range of 0 to 600 nm is 95% or more
There is a feature. The titanium oxide sol according to the present invention has a specific shape.
Titanium oxide particles having a uniform shape
Dispersed in dispersion medium, dispersibility, long-term stability, light resistance
Excellent aggregation and stable aggregation over a wide pH range
No, high absorbance of light in the ultraviolet range
In addition to its excellent effect, it is particularly effective in transmitting light of wavelengths in the visible light range.
Excellent and extremely high transparency. [0013] DETAILED DESCRIPTION OF THE INVENTION Titanium oxide sol according to the present invention
Will be described more specifically. Oxidized titanium according to the present invention
The length of the major axis of the titanium oxide fine particles in the sol is represented by L.
When the length of the short axis is D, L = 4 to 500 mμ,
D = 4 to 100 mμ in a specific shape of fine particles,
Not about 40-600mm anatase crystals
Particles grown or polycrystals aggregated with crystal particles
Body. [0014] Projection of electron micrographs of these fine particles
According to, non-spherical particles such as square, rectangular, and elliptical
The concrete shapes are cubic and rectangular
Shape, cylindrical shape, prismatic shape, spindle shape, flat plate shape, fiber shape and
Various shapes such as a needle shape can be exemplified. The length L and the short axis of the major axis of the titanium oxide particles
Is determined as follows. Ie acid
Observe the titanium oxide particles in the titanium oxide sol with an electron microscope.
And the longest length in the longitudinal direction is L,
In the direction perpendicular to the longitudinal direction at the location of L / 2
Let the length be the length D of the minor axis. In the titanium oxide sol according to the present invention, water
Length of titanium oxide particles dispersed in a dispersion medium such as
The length L of the major axis in the direction and the length D of the minor axis are as described below.
Although it varies depending on the production conditions of the titanium oxide sol, the present invention
According to the manufacturing conditions specified in
A sol in which titanium oxide particles of uniform particle size are dispersed is obtained.
You. That is, the acid in the obtained titanium oxide sol
The average value of the L / D values of the titanium halide particles is [L / D]_ATo be
And (1 ± 0.3) × [L / D]_AOxide having a value of
60% or more, preferably 65% or more of the total particles
More preferably, a sol having 70% or more is obtained.
It is. The titanium oxide sol according to the present invention is as described above.
In addition to the uniform shape, the size is also uniform,
The titanium oxide particles are well dispersed in the dispersion medium
It has excellent long-term stability and light resistance,
Light associated with high uniformity of size and size
Have biological characteristics. That is, the titanium oxide sol according to the present invention comprises
TiO_TwoAdjust the concentration to 0.005% by weight and measure.
The light transmittance in the wavelength range of 370 to 600 nm
95% or more. The titanium oxide sol of the present invention is contained therein.
The shape and size of the titanium oxide particles
Wavelength region longer than the long wavelength side in the ultraviolet region
In the wavelength range of 370 to 600 nm.
Has the same optical characteristics as conventional titanium oxide
Compared to the fine particle dispersion, in addition to the ultraviolet shielding effect,
In particular, it has excellent visible light transmittance (transparency). The sol of the present invention is prepared by
Even when mixed with organic solvents or replaced with these solvents, precipitates
Because it is stable without being formed, it can be used as a coating material
It increases dramatically compared to the conventional titanium oxide sol. The titanium oxide sol according to the present invention generally contains 5
It has a pH of ~ 9.
Even if alkali or alkali is added, the titanium oxide particles gel
No settling or precipitation occurs, pH 3-11
It is stable in a wide pH range. The titanium oxide particles in the titanium oxide sol
As for the concentration, a wide range of concentrations can be obtained stably according to the purpose.
However, in general, TiO_TwoAbout 30% by weight
It exists stably even when concentrated to such a high concentration, and the coexisting salt concentration is about
It can be extremely reduced to 0.05% by weight or less. Next, such a titanium oxide sol of the present invention is
The manufacturing method will be described. First, a conventionally known method
To prepare a gel or sol of hydrous titanic acid. Including
Water titanate gel is, for example, titanium chloride or titanium sulfate.
Neutralize any aqueous solution of titanium salt by adding alkali
Obtained by The hydrous titanic acid sol is a titanium salt.
Anion solution through an ion exchange resin to remove anions
Obtained by: Hydrous titanate sol or gel
Is not limited to the above method,
Can be widely used. The hydrous titanic acid here
Is a titanium oxide hydrate obtained by the above method
Or a generic term including titanium hydroxide. Next, the hydrated titanium obtained as described above
Add acid peroxide or gel or a mixture of these to
Add water and dissolve hydrated titanic acid to prepare a uniform aqueous solution
I do. At this time, if necessary, heat to about 50 ° C or more.
Is preferably stirred. At this time, hydrous titanic acid
Is too high, it takes a long time to dissolve hydrous titanic acid.
Requires additional time, and furthermore, undissolved gel precipitates,
Or the resulting aqueous solution is too viscous
I don't. For this reason TiO_TwoConcentration is about 10% by weight or less
It is more preferably about 5% by weight or less. The amount of hydrogen peroxide to be added is H_TwoO_Two/ Ti
O_TwoIf the weight ratio is 1 or more, the hydrous titanic acid is completely dissolved.
Can be understood. H_TwoO_Two/ TiO_TwoThe ratio is less than 1
In this case, the hydrous titanic acid is not completely dissolved and
Or sol remains, which is not preferable. Also H_TwoO_Two/ T
iO_TwoThe higher the ratio, the higher the dissolution rate of hydrous titanic acid
The reaction is completed in a short time, but the hydrogen peroxide is
, A large amount of unreacted hydrogen peroxide remains in the system
Will adversely affect the next step.
Absent. Therefore, H_TwoO_Two/ TiO_TwoThe ratio is preferably 1-6
Use hydrogen peroxide in an amount such that
It is preferable to use hydrogen peroxide in such an amount,
Hydrous titanic acid completely dissolves in about 0.5 to 20 hours
You. Next, the hydrated copper obtained as described above is used.
An inorganic compound is added to an aqueous solution in which
Mix a predetermined amount of the product and raise it to 60 ° C or higher, preferably 80 ° C or higher.
Heat to hydrolyze the titanic acid. By doing this
An acid in which titanium oxide particles of a specific shape as described above are dispersed
A titanium oxide sol is obtained. The inorganic compounds used here are preferably
Preferably, group III of the periodic table such as Al, Ti, Zr, S
Group IV such as i and Sn, Group V such as V and Sb, W etc.
At least one member selected from Group VI and Group VIII such as Fe
Alternatively, an inorganic compound of two or more elements is used. Mineralization
The compound may be in the form of a salt, oxide, hydroxide or ox.
Silicic acid or oxyacid salt is used. These are fixed
It may be added in the form of a body, or may be mixed as an aqueous solution.
No. A preferred method is to use gels of these inorganic compounds.
Or a sol. When using a sol, the average of the dispersed particles
The particle size is about 30 mμ or less, preferably about 15 mμ or less.
Preferably. For example, for silicon, silica
Gel, silica sol or silicic acid solution is used. here
The silicic acid solution referred to in
Low polymer of silicic acid obtained by dealkalization by exchange method etc.
Solution. Water glass is used as the inorganic compound.
Can also be. When the mixing amount of the inorganic compound is increased, the resulting acid
The long-term stability and light resistance of titanium sol increase,
Degree of sol is obtained. However, these effects are not
After reaching the bell, even if the mixing amount is increased further,
Increase in the effect of adding inorganic compounds such as stability and light resistance
It is not preferable because it will not be possible When the mixing amount is reduced, the obtained titanium oxide
The size of the particles becomes uneven or the particles aggregate.
Problems that occur. Consider the above
And the amount of inorganic compound to be mixed
Titanium weight in liquid_TwoAnd the inorganic compound
The weight of the material to oxide (MO_xRatio to the value converted to)_Two
/ MO_x(Weight ratio) is in the range of 0.25 to 200.
Is preferred. Further, TiO in the mixed solution_Two/ MO_xand
(TiO_Two+ MO_x) Of the titanium oxide particles obtained by
The shapes, especially their lengths, differ. The length of the resulting particles is L
/ D, it is generally TiO_Two/ MO_xIs large
The tendency that L / D becomes large is recognized. For example,
TiO_Two/ MO_x= About 10-30, L / D = about 3-6
A sol of particles is obtained, TiO_Two/ MO_x= About 50-100
Then, a sol in which long particles of L / D = about 10 to 20 are dispersed
can get. TiO_Two+ MO_xConcentration (y) and TiO_Two
/ MO_xAs a result of examining the relationship between (x) and L / D,
If y> 0.17x-1.30, L / D = 1 to 1
2 were obtained, and y ≦ 0.17x−1.30.
It was found that particles with L / D> 2 were obtained if present. A method for mixing the aqueous solution of titanic acid and the inorganic compound;
There is no particular limitation, and there is no
Organic compounds may be mixed at once, or an aqueous solution of titanic acid
And part of the inorganic compound are mixed first and heated,
, The rest of the two may be added. Further, the total amount of the inorganic compound and the aqueous solution of titanic acid
Mix and heat a portion of the solution first, and then
A method of adding an aqueous acid solution may be used. In addition, inorganic compounds
At the same time, hydrous titanic acid does not necessarily dissolve in hydrogen peroxide.
It is not necessary to dissolve it, and it is not necessary to dissolve it in hydrogen peroxide.
May be mixed at the stage of water or sol.
It may be mixed at the time of preparing the gel or sol of tanoic acid. Required
When heating and hydrolyzing an aqueous solution of titanic acid,
It suffices if an inorganic compound is present in the reaction system. An aqueous solution of titanic acid containing no inorganic compound is used.
When heated and hydrolyzed, the titanium oxide concentration is low.
If so, it will be a titanium oxide sol, but this one is
Is unstable, for example, when it is concentrated,
And a precipitate forms. In the method for producing such a titanium oxide sol,
As an inorganic compound to be mixed with the titanic acid aqueous solution
In the case of using a titanium compound, hydrated titanium titanate as a starting material is used.
Or sol may be used, or
It can be obtained by heating hydrolysis without adding inorganic compounds.
Titanium oxide sol (or gel) can also be used
You. In these cases, the hydrous titanate gel or sol is
After completely dissolving with hydrogen peroxide to make titanic acid aqueous solution
It is more preferable to mix the above titanium compound. The titanium oxide sol thus obtained
Can be used for the intended purpose as it is,
Concentration to an appropriate concentration by a known method such as evaporation and ultrafiltration
Can also be used. In some applications,
Mix with organic solvents such as lopanol and ethylene glycol
Alternatively, the solvent can be replaced to form an organic solvent dispersion sol.
You. [0038] The titanium oxide sol according to the present invention is
High uniformity of the shape and size of the fine titanium oxide particles
Excellent dispersibility and long-term stability and light resistance
Is excellent, and can be mixed with or replaced with an organic solvent.
Does not gel or precipitate. Further, the titanium sol of the present invention comprises titanium oxide
This is related to the high uniformity of particle shape and size.
Have specific optical properties, and
As for the hiding effect and transparency, conventional titanium oxide fine particles
It has particularly excellent properties as compared with the particle dispersion. Therefore, the titanium oxide sol of the present invention is
If used as a plastic compounding agent, plastic purple
Various effects such as prevention of deterioration due to outside lines can be expected.
If blended into a plastic sheet to be worn, conventional packaging materials
Long-term storage is possible as compared with. In addition, transparent substrates such as glass and plastic
When used as a surface coating agent for materials, excellent adhesion to the substrate
High refractive index with excellent transparency and UV shielding effect
A coating is obtained. The titanium oxide sol according to the present invention is used in cosmetics distribution.
It also has excellent effects as a mixture, such as water dispersion
The sol or the organic solvent dispersion sol is used as an oxide in an amount of about 0.1%.
When blended in cosmetics in an amount of 005% by weight or more, transparency,
Excellent cosmetics with excellent UV shielding effect and finish feeling
can get. Further, in the titanium oxide sol according to the present invention,
Excellent even in fields that take advantage of the shape characteristics of dispersed particles
The effect is obtained. For example, for moldings such as catalyst carriers
The particles are regulated by the force applied during molding
It is possible to improve the moldability by
Cracks may occur during drying or firing.
The compression strength and wear strength are improved. The present invention
Titanium oxide sol according to another titania, silica, a
Aggregate by treating with sol or liquid such as Lumina
Use of raw material has large pore volume and is light
Despite excellent compressive strength, wear strength and impact strength
A molded article can be obtained. Generally, the oxidation catalyst according to the present invention
When a tansol is used for molding, L / D ≧ 7
Sol containing particles of one type or two or more types
The effect is great when a sol is used. [0044] EXAMPLES The present invention will be described below with reference to examples.
The description is not limited to these examples. [0045] Example 1 Titanium sulfate was dissolved in pure water and TiO_Twoage
Thus, an aqueous solution containing 0.4% by weight was obtained. This aqueous solution is stirred
While stirring, gradually add 15% aqueous ammonia to this aqueous solution.
Was added to obtain a white slurry liquid having a pH of 8.5. This sla
The cake is filtered and washed, and the solid concentration is 9% by weight.
A cake of hydrous titanate gel was obtained. To 5.55 kg of this cake, 33% peroxide water was added.
After adding 6.06 kg of undiluted water and 13.4 kg of pure water, 80 ° C.
And heat for 5 hours._Two2.0% by weight of solution 2
5 kg were obtained. This titanic acid aqueous solution is transparent and
H was 8.1. Next, the particle diameter is 7 μm and the concentration is 15
130 g of silica sol in the amount of
After mixing 9 kg of the liquid and 10.8 kg of pure water, the mixture was mixed at 95 ° C for 6 hours.
Heated for 24 hours. The solution was initially a tan liquid, but 6
After 24 hours, a milky white transparent colloid solution was obtained. The colloid liquid thus obtained is evacuated.
When concentrated by the evaporation method, a sol as shown in Table 1 was obtained.
Was. Table 1 shows the properties of the sol and the properties of the dispersed particles.
You. [0049] Example 2 In Example 1, 130 g of silica sol was added.
The amount of pure water mixed with 9 kg of titanic acid aqueous solution is 1.0 kg.
The heating temperature to 130 ° C. and the heating time to 11:00
Titanium oxide sol in the same manner as in Example 1 except that
Was produced to obtain a titanium oxide sol as shown in Table 1. [0050] EXAMPLE 3 The aqueous solution of titanic acid and silica gel of Example 1 were used.
TiO_Two/ SiO_Two= 1.8, solids content (TiO_Two
+ SiO_Two) Add pure water to make up 0.1% by weight and mix.
After heating at 95 ° C for 48 hours, do not maintain the temperature at 95 ° C.
The titanic acid aqueous solution was diluted to 0.1% by weight.
Of TiO_Two/ SiO_Two= 60 hours until 7.2
And added sequentially. Then keep this temperature for 48 hours
Was. Table 1 shows the properties of the obtained sol after concentration.
You. FIG. 2 shows the titanium oxide particles dispersed in the sol.
The electron micrograph of a child is shown. [0052] EXAMPLE 4 The aqueous solution of titanic acid and silica gel of Example 1 were used.
TiO_Two/ SiO_Two= 6.5, solid content concentration 2.0 weight
% Water and mixed at 95 ° C. for 60 hours
After heating, maintain the temperature at 95 ° C.
Aqueous solution (2.0% by weight)_Two/ SiO_Two= 15
Over 60 hours. Then this temperature
Was maintained for 60 hours. The properties of the obtained titanium oxide sol after concentration were
It is shown in Table 1. [0054] Embodiment 5 Titanium chloride was dissolved in pure water and TiO_Twoage
To obtain an aqueous solution containing 5.0% by weight. Stir this aqueous solution
While gradually adding 15% by weight aqueous ammonia to this aqueous solution.
To obtain a white slurry liquid having a pH of 8.5. This
After the rally is filtered and washed, the solid content is 10% by weight.
A cake of a hydrous titanate gel was obtained. To 5.0 kg of this cake, 35% hydrogen peroxide was added.
After adding 5.71 kg of water and 14.0 kg of pure water, at 80 ° C.
Heat for 3 hours_Two25% of a 2.0% by weight solution
g was obtained. This titanic acid aqueous solution is transparent,
Was 8.4. Next, when the particle diameter is 7 mμ and the concentration is 15
66.7 g of silica sol in an amount of
200 g of the liquid and 1,147 g of pure water are mixed, and heated at a heating temperature.
Example except that the heating time was 150 hours and the heating time was 300 hours.
A titanium oxide sol was produced in the same manner as
Thus, a titanium oxide sol was obtained. [0057] EXAMPLE 6 The aqueous solution of titanic acid and silica gel of Example 5 were used.
TiO_Two/ SiO_Two= 2.5, solid concentration 1.6
Pure water was added and mixed to give a
Except for the heating for a period of time,
Thus, a titanium oxide sol was obtained. [0058] Example 7 9 kg of the aqueous solution of titanic acid of Example 1 was used.
After mixing 130 g of silica sol with 191 kg of pure water,
Heated at 5 ° C. for 60 hours. Then, the same as in Example 1
The sol shown in Table 1 was obtained by concentrating by the method. Also, FIG.
4 shows an electron micrograph of the obtained titanium oxide particles. [0059] Example 8 The aqueous solution of titanic acid obtained in Example 1 was 1.0
After mixing 100 kg of pure water and 200 kg of pure water, heat at 95 ° C for 2 hours
And TiO_Two0.01% by weight of titanium oxide sol
Obtained. This sol was used in place of the silica sol of Example 7.
Hydrolysis under the same conditions as in Example 7 except for
A sol as shown in 1 was obtained. [0060] Example 9 0.036% by weight as zirconium oxide
50 kg of zirconium chloride aqueous solution containing
Put in a scoel and mix well with 0.1N ammonia water
2.9 kg were added slowly. Further, this solution was added
After heating for 0 hours, the zirconium oxide concentration was 0.0
34% by weight and a thin milky white sol having a pH of 1.8 was obtained.
Was done. Further, 0.1N ammonia water was added to this solution.
After mixing and adjusting the pH to 4.8, chloride ion was added to the filtrate with pure water.
Washed until no more was detected. Jill obtained above
The konia sol and the titanic acid aqueous solution of Example 1 were mixed with TiO 2_Two/
ZrO_Two= 10 and then the solids concentration
(TiO_Two/ ZrO_Two) Is 0.1% by weight pure water
Was added and heated at 95 ° C. for 60 hours. The obtained sol is concentrated
Upon contraction, a sol as shown in Table 1 was obtained. [0062] Example 10 Titanium sulfate was dissolved in pure water and TiO_TwoWhen
Thus, an aqueous solution containing 5.0% by weight was obtained. To this, sulfuric acid second
Iron to TiO_Two/ Fe_TwoO_Three= 97/3 (weight ratio)
And mixed and dissolved. While stirring this aqueous solution,
15% by weight of aqueous ammonia is gradually added to this aqueous solution.
Thus, a brown slurry liquid having a pH of 8.7 was obtained. This sla
The solids are filtered and washed, and the solid content (TiO 2_Two+ Fe_TwoO_Three)
To obtain a cake of hydrous titanic acid gel containing 10% by weight. To 5.0 kg of this cake was added 35% hydrogen peroxide water.
After adding 5.71 kg and 14.0 kg of pure water, the mixture was added at 80 ° C. for 3 hours.
Heating for TiO_Two25k of 1.94% by weight solution
g was obtained. This titanic acid aqueous solution is brown and transparent and has a pH
8.4. Next, 460 kg of water was added to this solution and mixed.
After that, the mixture was heated at 130 ° C. for 8 hours. Solution initially light brown
After 8 hours, it became a pale yellowish white transparent sol solution.
Was. When the obtained sol was concentrated, the sol as shown in Table 1 was obtained.
I got [0065] Example 11 Titanic acid aqueous solution and stannic acid of Example 1
Potash with TiO_Two/ SnO_Two= 9/1 (weight ratio), solid content concentration
Degree (TiO_Two/ SnO_Two) Pure water to be 0.1% by weight
Was added and mixed, and heated at 130 ° C. for 5 hours. Solution
Initially a yellow-brown liquid, but after 5 hours a milky transparent sol
It became. The sol solution thus obtained is concentrated,
A sol as shown in Table 1 was obtained. [0067] Embodiments 12 and 14_Two/ Si
O_TwoThe weight ratio was 20 (Example 12) and 30 (Example
Example 13) and Example 7 except that 80 (Example 14) was used.
When hydrolysis was carried out under the same conditions, as shown in Table 1,
A titanium oxide sol was obtained. FIG. 4 shows the titanium oxide obtained in Example 13.
3 shows a transmission electron micrograph of the particles. [0069] Example 15 Oxidized titanium oxide before concentration obtained in Example 13
The titanic acid aqueous solution obtained in Example 1 was added to Ti
O_Two/ SiO_Two= 130, solid content concentration becomes 0.1% by weight
And heat at 100 ° C for 84 hours to concentrate.
As a result, a sol as shown in Table 1 was obtained. [0070] Embodiment 16 The silica sol of Example 1 and aqueous titanic acid
The solution is TiO_Two/ SiO_Two= 30, solid concentration 1.0 weight
% In an autoclave at 130 ° C.
Concentrated milky sol obtained by heating for 2 hours at
Then, a sol as shown in Table 1 was obtained. [0071] Example 17 The titanium oxide sol obtained in Example 2 was purified
Diluted with water, TiO_TwoAdjusted to a concentration of 0.005% by weight
Sample (Sample A) and titanium oxide obtained in Example 7
The sol was similarly adjusted to 0.005% by weight and the sample (sample
Regarding B), the wavelength region (25
0 to about 360 nm) and high wavelength in the ultraviolet region
Wavelength including the side and the visible light region (about 370 to 600 n
m) was measured. For comparison, titanium chloride was oxidized in the gas phase.
The obtained titanium oxide fine particles (Aerosil manufactured by Degussa,
P-25) with TiO_TwoThe concentration will be 0.005% by weight
The same measurement was performed on a sample (sample C) dispersed in pure water.
Was performed. The result is shown in FIG. In the figure, A, B,
C is the absorbance, and A ', B', and C 'are the transmittances. In addition,
The measurement was performed using a spectrophotometer (type 330 manufactured by Hitachi, Ltd .: width 10 mm).
Using a transparent quartz cell). As shown, the second embodiment and the second embodiment
Light transmittance of samples A and B obtained from titanium oxide sol of No. 7
A ′ and B ′ represent wavelengths 3 on the long wavelength side in the ultraviolet region.
95% or more at 70 nm (A '; 97.5%,
B '; 95%), from which the wavelength 6 in the visible light region
Over 00 nm, increases monotonically with increasing wavelength
And stabilized at almost 100%. Then, these samples A and
And B further have a wavelength of 280 nm belonging to the ultraviolet region.
High absorbances A and B of 1.6 or more. On the other hand, Sample C shown for comparison
Has a long wavelength of 400 n belonging to visible light.
m, it only shows a transmittance of about 67%.
90% or less in the wavelength region of visible light from 0 to 600 nm
It was full. In addition, the sample C has a wavelength of 280 nm.
It showed only an absorbance C of about 1.3. [0075] Comparative Example 1 The hydrous titanate gel obtained in Example 1 was purified.
Diluted with water, TiO_TwoSuch that the concentration is 2.0% by weight
A suspension was obtained. 0.1N hydrochloric acid is added to this until it becomes a sol.
Was added slowly. Heat the obtained sol at 80 ° C for 1 hour
After stabilizing, evaporate the water under reduced pressure and concentrate by peptization.
A compacted sol was obtained. This sol can be concentrated up to 20% by weight.
However, the pH was as low as 1.7, and chlorine ions were added at 2.
The sol contained 1% by weight. Table 1 shows the characteristics of this sol.
Shown in FIG. 5 shows the oxide oxide obtained from this sol.
3 shows a transmission electron micrograph of tan particles. [0077] [Table 1][0078] [Table 2]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is an absorbance curve and a transmittance curve of a titanium oxide sol according to the present invention and a commercially available titanium oxide sol, in which A, B, A ′ and B ′ are titanium oxide sol according to the present invention. In the figure, C and C ′ relate to a commercially available titanium oxide sol. FIG. 2 is an electron micrograph of titanium oxide particles according to the present invention. FIG. 3 is an electron micrograph of titanium oxide particles according to the present invention. FIG. 4 is an electron micrograph of titanium oxide particles according to the present invention. FIG. 5 is an electron micrograph of titanium oxide particles obtained in a comparative example.

Claims (1)

(57) [Claims] Titanium oxide particles having a major axis length L of 4 to 500 mμ and a minor axis length D of 4 to 100 μm are dispersed in a dispersion medium, and the average L / D ratio L / D When the value is [L / D] _A , (1 ± 0.3) × [L / D]
_A titanium oxide sol in which 60% or more of all the particles are present in the range of _{A. When} the TiO ₂ concentration is adjusted to 0.005% by weight and measured, the light transmittance in a wavelength region of 370 to 600 nm is 95%. A titanium oxide sol characterized by the above.