JPH06115942A - Ultrafine particle compound oxide of titanium-iron and its production - Google Patents

Abstract

PURPOSE:To improve ultraviolet light screening effect by melting and evaporating Ti.Fe-based raw material crude particles having a specific weight ratio of Fe/Ti at high temperature into a vapor phase. CONSTITUTION:A mixed gas of Ar/O2 is fed from a core gas source 12 to a high-frequency plasma torch 2 and made into a thermal plasma at high temperature to form a plasma frame PF in a reactor 1. Ti.Fe-based raw material crude particles having a weight ratio of Fe/Ti of 3X10<-5> to 3X10<-2> is supplied from a raw material feeder 5 with a carrier gas such as Ar to a raw material supply part 6 and brought into contact with the high-temperature plasma frame. The Ti.Fe-based raw material crude particles are instantly melted and evaporated into a vapor phase simultaneously with the contact, reacted with an atmosphere gas in the reactor 1 and condensed to give high-purity ultrafine powder. Then the ultrafine powder is made into a misty state together with the atmosphere gas, moved to a collecting column 8, collected by a filter 9, accumulated at the lower part of the collecting column 8 to give the objective white Ti.Fe ultrafine particle compound oxide having 0.01-0.3mum particle diameter and a weight ratio of Fe/Ti of 3X10<-5> to 3X10<-2>.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION The present invention relates to an ultraviolet A wave region (wavelength 32) which cannot be sufficiently shielded by titanium oxide alone.
The present invention relates to an ultrafine particle composite oxide of titanium and iron which is a whiteish ultrafine particle powder having an excellent shielding power even in the range of 0 to 400 nm) and a method for producing the same.

[0002]

2. Description of the Related Art Conventionally, titanium oxide powder has been used as a raw material resin for chemical fibers or in the production of cosmetics having an ultraviolet shielding effect by blending it with a cosmetic base due to its characteristics of ultraviolet shielding power or high refractive index. It is used for the production of clothing having an ultraviolet ray shielding effect by mixing and spinning, or for the production of an ultraviolet ray shielding material by blending or coating with plastic. However, the titanium oxide particles are in the ultraviolet B wave region (wavelength 280 to 280).
At 320 nm, it shows an excellent shielding effect, but it is the ultraviolet light A that is closest to visible light and reaches the surface of the earth 10 times as much as the ultraviolet B wave.
There is a problem that the shielding effect for the wave region (320 nm to 400 nm) is not sufficient. Ultraviolet B waves have weak penetrating power but cause rapid inflammation and burn the skin. On the other hand, ultraviolet A waves have high penetrating power of the skin and cause pigmentation, causing spots and freckles. It is said. Therefore, it is required to have a sufficient shielding power not only for the B wave but also for the A wave recently.

As a solution to this problem, for example, titanium oxide / oxidized by mixing iron oxide with iron oxide having a relatively large shielding effect in the ultraviolet A wave region in a weight ratio of 0.05 to 50 with respect to titanium oxide. An iron composite sol has been proposed (JP-A-2-178219). However, when a considerable amount of iron oxide is mixed with titanium oxide like this,
The mixture is colored yellow to brown (the more iron oxide is mixed, the browner it is), and compounding these colored particles with cosmetics, fibers, and plastics has an unfavorable effect on the final product. There is.

As a measure to shield the ultraviolet A wave,
In addition to mixing titanium oxide with a harmless inorganic compound such as iron oxide, it has been proposed to add various organic compound-based ultraviolet absorbers, but in this case there is a concern that it may cause biochemical harm. Therefore, an excellent ultraviolet shielding material based on an inorganic compound that is less harmful is demanded.

On the other hand, in order for the ultraviolet shielding agent containing titanium oxide as the main component to exert its effect in each of the above-mentioned uses, the smaller the particle size is, the better the dispersion stability is.
It is desirable that the particles are in the form of ultrafine particles having a size of μm or less. Therefore, for example, in the above-mentioned conventional example, it has been proposed to hydrolyze a hydrated titanium oxide and a hydrated iron oxide dissolved in hydrogen peroxide to form a sol, but the manufacturing method thereof is complicated and Since the cooling is repeated, there is a problem that the manufacturing takes a very long time.

[0006]

DISCLOSURE OF THE INVENTION The present invention is intended to solve various problems of the above-mentioned conventional ultraviolet shielding agents all at once, and has an excellent shielding effect also in the ultraviolet A wave region. It has an extremely small amount of iron and is remarkably whiter than conventional ones, and there is no problem of coloring due to iron oxide, and it is in the form of ultrafine particles. An object of the present invention is to provide a titanium-iron composite oxide that can be easily manufactured and a method for producing the same.

[0007]

Means for Solving the Problems In the process of studying ultrafine particles, the inventor of the present invention melts titanium and iron simultaneously under high temperature of thermal plasma and vaporizes them by vaporizing them to form titanium and iron. It has been found that a composite oxide of composite ultrafine particles which has not been obtained in the past can be obtained, and that the ultrafine particle composite oxide has an excellent effect of shielding an ultraviolet A wave with a very small amount of iron, and the present invention has been made. It has arrived. That is, in the present invention, the iron / titanium (weight ratio) is 0.00003 to 0.03.
The above problem can be solved by the titanium-iron ultrafine particle composite oxide. The ultrafine particle composite oxide of the present invention has a particle size of 0.01 μm to 0.3.
Ultrafine particles in the range of μm are desirable.

The titanium / iron ultrafine particle composite oxide of the present invention has an iron / titanium (weight ratio) of 0.00003 to 0.03.
It can be produced by melting and evaporating the titanium / iron-based raw material coarse particles as described above at a high temperature to form a gas phase, thereby generating and collecting ultrafine particle composite oxides of titanium / iron.

The titanium / iron-based raw material coarse particles as a starting material include metallic titanium powder containing metallic iron, a mixture of metallic titanium powder and iron oxide powder, a mixture of titanium oxide powder and metallic iron powder, and titanium oxide powder. And a mixture of iron oxide powder and a mixture of metallic titanium powder and metallic iron powder can be used. These starting materials are
By supplying the high temperature induction heat plasma, the direct current heat plasma, or the high temperature combustion flame at a high temperature of 3000 ° C. or higher with a carrier gas, the carrier gas is instantly melted and vaporized to form a gas phase. New titanium-iron composite oxide ultrafine particles are formed by liquid phase reaction in the cooling process in the high temperature region after being vaporized and oxidized. The titanium-iron composite ultrafine particle oxide is obtained by melting and evaporating the starting material itself if the starting material is titanium oxide or iron oxide coarse particles such as iron oxide, or oxygen if the starting material is metallic titanium or metallic iron. Obtained by melt evaporation in gas.

The titanium / iron composite oxide thus obtained is a white or flesh-colored ultrafine particle powder having an average particle size of about 0.1 μm in a particle size range of 0.01 μm to 0.3 μm. Presents. And, the weight ratio to titanium is 0.
Although it contains a very small amount of iron in the range of 00003 to 0.03, the iron / titanium (weight ratio) of iron oxide is 0.67 or more in the A wave region as well as the B wave region of ultraviolet light. It has an excellent shielding power equal to or more than that of a mixture of fine particles and titanium oxide ultrafine particles. Titanium obtained by the above method
The ultrafine particle composite oxide of iron having an iron / titanium (weight ratio) in the range of 0.00003 to 0.01 is excellent in ultraviolet ray shielding power and is hardly colored. Iron / Titanium (weight ratio)
However, when it is less than 0.00003, the effect of shielding A-wave of ultraviolet rays is not remarkable, and when it is 0.03 or more, it is gradually colored in dark brown, which is not preferable.

The particle size of the ultrafine particle composite oxide does not have a great influence on the absorbance characteristics, but the dispersibility
Since it has a great effect on sedimentation stability, 0.01 μm ~
The range is 0.3 μm, preferably about 0.1 μm or less. The particle size can be controlled by the energy output of a high temperature source such as high frequency induction heating output, the feed rate of raw material coarse particles, and the gas feed rate. Generally, the smaller the feed material feed rate / gas feed rate, the smaller the particles. As described above, the ultrafine particle composite oxide according to the present invention has an excellent shielding effect also in the ultraviolet A wave region and the B wave region, and has a white or pale skin color and is an ultrafine particle. As an ultraviolet shielding material, it can be applied to an ultraviolet shielding material such as cosmetics, fibers, clothes, plastics, paints, and the like.

[0012]

EXAMPLES Examples of the titanium-iron ultrafine particle composite oxide and the method for producing the same according to the present invention will be described below.
FIG. 1 shows an embodiment of the manufacturing apparatus. In the figure, 1 is a reaction vessel, 2 is a high-frequency plasma torch attached to the upper opening of the reaction vessel, 3 is its high-frequency power source, 4
Is a heating coil connected to the high frequency power source, 5 is a raw material feeder for supplying raw material powder to a raw material supply section 6 between the reaction vessel 1 and the open end surface of the plasma torch, 7 is a collector, 8 is the collector Collecting cylinder, 9 is a filter provided in the collecting cylinder,
10 is a conduit provided between the reaction container and the collection cylinder,
Reference numeral 11 is a gas pump. The high frequency plasma torch 2
When an argon gas, a nitrogen gas, an oxygen gas, or a mixed gas thereof is supplied from the core gas source 12, the high frequency energy applied by the heating coil 4 causes the plasma flame PF to generate thermal plasma at high temperature. .
The raw material coarse particles accommodated in the raw material feeder 5 are placed on a carrier gas such as Ar gas supplied from a carrier gas source, supplied from the raw material feeder to the raw material supply unit 6, and contact with the high temperature plasma flame.

The raw material coarse particles are instantly dissolved and vaporized by contacting with a high temperature plasma flame to form a gas phase, and react with the atmospheric gas in the reaction vessel 1 to condense in the atmospheric gas to form a high-purity ultrafine powder. Then, the atmospheric gas is converted into a smoke-like form and is moved into the collection cylinder, and is captured by the filter 9 and accumulated in the lower part of the collection cylinder 8. In addition,
The discharge side pipe of the air pump 11 that discharges the atmospheric gas by communicating with the inside of the filter of the collection cylinder is branched, one is connected to the discharge port through the pipe P2, and the other is connected through the pipe P3. It is connected to the reaction vessel 1 to supply the recycled gas into the reaction vessel.

FIG. 2 shows another embodiment of the apparatus for producing titanium-iron ultrafine particle composite oxide according to the present invention using direct current thermal plasma, in which the thermal plasma generator is a direct current thermal plasma generator. Except for the above, the other structure is almost the same as that of the apparatus shown in FIG. Therefore, the same parts are denoted by the same reference numerals as those in the above-described embodiment, and only different configurations will be described. 2 in the figure
Reference numeral 1 is a reaction vessel, and a pair of DC plasma torches 22 and 23 are provided at the upper opening of the reaction vessel. Each DC plasma torch 22, 23 has a DC power source 2
The plasma forming gas source 26 is connected together with the connection of Nos. 4 and 25. As the plasma forming gas, a mixed gas of argon gas and nitrogen gas or oxygen gas can be used, and is selected depending on the type of raw material coarse particles. Raw material feeders 27 and 28 are directly connected to the plasma torches 22 and 23, and raw material coarse particles 29 are added to the generated DC thermal plasma.
Are to be supplied. In this embodiment, argon gas supplied from the carrier gas source 30 is used as the carrier gas for the raw material coarse particles, but the present invention is not limited to this. Further, in this embodiment, two DC plasma torches are provided, but of course, one may be provided. 3
Reference numerals 1 and 32 are gas pumps.

Next, an embodiment of the titanium-iron ultrafine particle composite oxide and the method for producing the same according to the present invention will be described using the apparatus shown in FIG. Example 1 A mixed gas flow (50 × 10 ³ cc / min) of Ar gas and O ₂ gas was supplied from the core gas source 12 to the plasma torch 2, and the output (frequency 3.68M) given by the high frequency induction coil 4 was supplied.
Hz, output 20 kW), center temperature is 10,000 at normal pressure
A thermal plasma above 0 ° C. is formed. Fe / Ti (weight ratio)
The metallic titanium containing iron corresponding to 0.00005 is roughly crushed, and powder having a particle size of 300 mesh or less is used as raw material coarse particles. The titanium / iron-based raw material coarse particles are fluidized with Ar gas and continuously fed at 10 g / min from the raw material feeder 5 to the raw material supply section 6, and the high frequency induction thermal plasma flame 300
Supply to high temperature part above 0 ℃. The supplied raw material coarse particles are instantly melted and vaporized by high temperature thermal plasma to form a gas phase,
New titanium / iron composite oxide ultrafine particles are formed by liquid phase reaction at high temperature while being oxidized by atmospheric gas,
It can be taken out by being collected by the filter 9, dropped and accumulated in the collecting cylinder 8. The titanium-iron composite oxide ultrafine particles thus obtained were white and the average particle size was 0.1 when the particle size was measured with a laser particle size distribution meter.
It was an ultrafine particle of μm. Then, the titanium-iron composite oxide ultrafine particles are suspended at a concentration of 50 mg / 10 ³ cc, and a cell having a thickness of 10 mm is used to emit light having a wavelength of 2 to an ultraviolet or visible light region.
Absorbance was measured in the range of 00 to 700 nm. The result is shown by a broken line in the graph of FIG.

On the other hand, as a comparative example, a commercially available ultrafine particle titanium oxide having a particle size of 0.03 μm (Comparative Example 1) was suspended at a concentration of 50 mg / 10 ³ cc in the same manner as in the above example, and a cell having a thickness of 10 mm was used. Wavelengths in the range of ultraviolet rays to visible rays of 200 to 700
The absorbance was measured in the range of nm, and the result is similarly shown by the solid line in FIG. As is clear from the figure, the material of this example is significantly higher than the ultrafine titanium oxide, especially in the ultraviolet A wave region, and the ultraviolet A wave shielding effect is very excellent. Further, it has a sufficient shielding effect even in the ultraviolet B wave region.

Example 2 The same titanium / iron-based raw material coarse particles as in the above example were produced under the same conditions by the production apparatus using the DC thermal plasma shown in FIG. The ultrafine particle composite oxide thus obtained is
It had a white appearance. Then, the absorbance curve was measured under the same conditions as in Example 1. The result is shown by a broken line in FIG. As is clear from the figure, even when manufactured by the apparatus of FIG. 2 which uses direct-current thermal plasma, it shows almost the same absorbance curve as when manufactured by the apparatus of FIG. 1 which uses high-frequency thermal plasma. It can be seen that the A wave shielding effect is very excellent. The absorbance curve shown by the solid line in the figure is that of Comparative Example 1 described above.

Example 3 As titanium / iron-based raw material coarse particles, iron / titanium (weight ratio)
Was selected to contain 0.00005 of metallic titanium powder and iron oxide powder, and ultrafine particle composite oxide was obtained from the titanium / iron-based raw material coarse particles by the apparatus shown in FIG. . The obtained ultrafine particle composite oxide was also white in color. An absorbance curve measured under the same conditions as above is shown in FIG. 5 together with Comparative Example 1. Also in this example, it is understood that the ultraviolet ray shielding effect is excellent especially in the ultraviolet ray A wave region.

Next, in order to further investigate the characteristics of the ultrafine-particle composite oxide according to the present invention, the ultrafine-particle composite oxide produced by the method of the present invention and the component ratio of titanium and iron are the above-mentioned ultrafine-particle composite oxide. A test was conducted to compare the degree of ultraviolet shielding with respect to a mixture of titanium oxide ultrafine particles and iron oxide ultrafine particles produced in advance so as to be the same as the oxide. Example 4 To carry out the test, iron / titanium (weight ratio) is 0.000.
7, a mixture of metallic titanium powder and iron oxide powder of 300 mesh or less was produced in the same manner as in Example 1 using the production apparatus of FIG. Got In addition, a titanium-iron ultrafine particle mixture is prepared by mixing ultrafine particles of pure titanium oxide containing almost no iron with an amount of iron oxide particles such that the composition ratio of the ultrafine particle composite oxide and titanium and iron is the same. (Comparative example 2) was obtained. Both thus obtained were separately suspended at a concentration of 50 mg / 10 ³ cc, and the absorbance was measured in a cell having a thickness of 10 mm in the wavelength range of 200 to 700 nm which is the range of ultraviolet rays or visible rays. The result is shown in FIG. In the figure, the absorbance curve shown by the dotted line is that of this example, and the absorbance curve shown by the solid line is that of Comparative Example 2.

As can be seen from the figure, even though both have the same iron / titanium (weight ratio), the example of the present invention has a much higher degree of shielding in the ultraviolet A wave region than the comparative example. You can see that That is, the titanium-iron composite oxide according to the present invention is remarkably improved in ultraviolet shielding properties, particularly in the A-wave region, as compared with a mixture of iron oxide and titanium oxide. This means that the titanium / iron composite oxide according to the present invention is not a simple mixture of titanium oxide and iron oxide, but a new solid-phased compound is formed by vaporizing titanium / iron-based raw material coarse particles at high temperature. Or, it is considered that a new complex oxide was generated by partially invading the crystal lattice of titanium oxide and substituting it with titanium element. And
The fact that the iron content contained in the complex oxide of the present invention was not easily eluted even when the complex oxide of the present invention was heated with dilute hydrochloric acid was clear that the ultrafine particle complex oxide of the present invention is not a simple mixture. is there.

Further, in order to obtain a mixture of titanium oxide fine particles and iron oxide fine particles having the same absorption spectrum as that of Example 1 of the present invention, the iron oxide fine particles are mixed with the iron oxide fine particles by changing the mixing ratio of the iron oxide fine particles. As a result of later mixing to obtain a titanium oxide fine particle / iron oxide fine particle mixture, a mixture of iron oxide so that the iron / titanium (weight ratio) was 0.67 was the most absent in the absorbance spectrum of Example 1. It showed a close absorbance spectrum. That is, the iron / titanium (weight ratio) of the present invention having an extremely small amount of iron of 0.00005 and iron oxide fine particles containing 40% by weight of iron by the conventional method.
It can be said that it has an ultraviolet ray shielding effect equivalent to that obtained by mixing iron oxide fine particles so that As a result, the comparative example in which 40% by weight of iron oxide was mixed was naturally dark brown, whereas the example of this example was white.

[0022]Examples 5, 6, 7  Fe / Ti (weight ratio) as titanium / iron raw material coarse particles
Metallic titanium containing metallic iron equivalent to 0.00003
Powdered iron (Example 5), Fe / Ti (weight ratio) is 0.0001
Metallic titanium powder containing metallic iron corresponding to 5 (Example
6) and iron / titanium (weight ratio) to be 0.03
Mixture of mixed metallic titanium powder and iron oxide powder (implemented
Example 7) is replaced with the manufacturing apparatus of FIG.
Manufactured by various methods, and ultrafine particles of titanium and iron of Examples 5 to 7
A child composite oxide was obtained. As a comparative example, titanium / iron
Fe / Ti (weight ratio) of the system raw material coarse particles is 0.0000
Starting with metallic titanium powder iron containing metallic iron equivalent to 2
As a raw material, titanium-iron ultrafine particle composite acid is processed by the same method.
A compound was obtained (Comparative Example 3). Those ultrafine particle composite oxides
Absorbance due to difference in iron content by measuring the absorbance of
And the color of the ultrafine-particle composite oxide were observed. So
The results are shown in FIG. 7 and Table 1. As is clear from the figure
In addition, the higher the iron oxide content, the more ultraviolet A wave region and B
Absorbance is high in both the wave region and the ultraviolet A wave region and
And the B-wave region have sufficient shielding effect, but
The weight ratio of iron falls below 0.00002 as in Comparative Example 3.
And the shielding effect in the ultraviolet A wave region is reduced.

[Table 1] Moreover, the iron content (weight ratio) of the color is 0.0000.
In the case of No. 3, it is pure white, and gradually becomes lighter as the iron content increases, and at 0.03, a pale skin color is exhibited, and an ultrafine particle composite oxide having a color desirable for cosmetics is obtained. Therefore, by appropriately selecting the content of iron oxide according to the application, it is possible to obtain an ultrafine particle composite oxide having an excellent ultraviolet shielding effect and a desired color.

[0023]

INDUSTRIAL APPLICABILITY The titanium-iron ultrafine-particle composite oxide of the present invention has an excellent ultraviolet-shielding effect in the ultraviolet A-wave region and B-wave region because iron forms an ultrafine-particle composite oxide with titanium. In addition, since it has a very small amount of iron as compared with the conventional one, it is a white or flesh-colored ultrafine particle, and there is no problem of coloring due to iron oxide. Further, the manufacturing method thereof is simple without requiring complicated steps, can be easily performed in a short time and can improve productivity, and a homogeneous titanium-iron ultrafine particle composite oxide can be obtained at low cost. .

[Brief description of drawings]

FIG. 1 is a schematic explanatory view of an apparatus for producing a titanium / iron ultrafine particle composite oxide of the present invention.

FIG. 2 is a schematic explanatory view of another manufacturing apparatus of the titanium / iron ultrafine particle composite oxide of the present invention.

FIG. 3 is a diagram showing an absorbance spectrum of titanium / iron ultrafine particle composite oxide and titanium oxide according to an example of the present invention.

FIG. 4 is a diagram showing an absorbance spectrum of titanium-iron ultrafine particle composite oxide and titanium oxide according to another embodiment of the present invention.

FIG. 5 is a diagram showing an absorbance spectrum of titanium-iron ultrafine particle composite oxide and titanium oxide according to still another embodiment of the present invention.

FIG. 6 is a diagram showing absorbance spectra of titanium-iron ultrafine particle composite oxides according to still another embodiment of the present invention and a comparative example.

FIG. 7 is a diagram showing an absorbance spectrum of titanium-iron ultrafine particle composite oxides according to still another embodiment of the present invention when the iron content is changed.

[Explanation of symbols]

1, 21 Reaction container 2 High frequency plasma torch 4 Heating coil 5, 27, 28
Raw material feeder 7 Collector 8 Collection tube 9 Filter 10 Conduit 11, 31, 32 Gas pump 22, 23 DC plasma torch

Claims (11)

[Claims] 1. The iron / titanium (weight ratio) is 0.00003.
An ultrafine particle composite oxide of titanium and iron of about 0.03. 2. The ultrafine particle composite oxide according to claim 1, wherein the particle diameter is in the range of 0.01 μm to 0.3 μm. 3. Iron / titanium (weight ratio) is 0.00003-
Titanium characterized in that ultrafine titanium composite particles of titanium / iron are produced and collected by melting and evaporating titanium / iron-based raw material coarse particles of 0.03 at a high temperature to form a gas phase. A method for producing an ultrafine particle composite oxide of iron. 4. The method for producing an ultrafine particle composite oxide according to claim 3, wherein the coarse particles of titanium / iron-based raw material are metallic titanium powder containing metallic iron. 5. The method for producing an ultrafine particle composite oxide according to claim 3, wherein the titanium / iron-based raw material coarse particles are a mixture of metallic titanium powder and iron oxide powder. 6. The method for producing an ultrafine particle composite oxide according to claim 3, wherein the titanium / iron-based raw material coarse particles are a mixture of titanium oxide powder and metallic iron powder. 7. The method for producing an ultrafine particle composite oxide according to claim 3, wherein the titanium / iron-based raw material coarse particles are a mixture of titanium oxide powder and iron oxide powder. 8. The method for producing an ultrafine particle composite oxide according to claim 3, wherein the titanium / iron-based raw material coarse particles are a mixture of metallic titanium powder and metallic iron powder. 9. The method for producing an ultrafine particle composite oxide of titanium / iron according to claim 3, wherein the titanium / iron-based raw material coarse particles are melted and vaporized by being supplied to a high temperature formed by high frequency induction thermal plasma. 10. The method for producing an ultrafine particle composite oxide of titanium / iron according to claim 3, wherein the titanium / iron-based raw material coarse particles are melted and vaporized by being supplied to a high temperature formed by direct current thermal plasma. 11. The method for producing an ultrafine particle composite oxide of titanium / iron according to claim 3, wherein the titanium / iron-based raw material coarse particles are melted and vaporized by being supplied to a high temperature formed by a high temperature combustion flame.