JP2008150240A - Titanium oxide and its production method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To obtain lower-order titanium oxide which is little collapsed of a particle form and has desired blackness. <P>SOLUTION: Titanium oxide, wherein 0.01-5 wt.% carbon element is contained in particles of lower-order titanium oxide expressed by general formula: TiO<SB>2-x</SB>(wherein x is within a range of 0.05-0.8) with a lightness L is in the range of 5-70, is produced by heating titanium dioxide at 700-1,200°C in an atmosphere of a hydrocarbon gas such as propane, ethane or the like. By this method, needle-shaped titanium oxide having major axis length of 0.5-10 μm and minor axis length of 0.02-1 μm, plate-shaped titanium oxide having a plate shape that the ratio of length to thickness is ≥3, or the like are obtained, and the obtained titanium oxide is used for a black pigment, an infrared absorbing agent, a conductive agent, a charge controlling agent, a toner external additive, an electromagnetic shielding agent or the like. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to titanium oxide and a method for producing the same. Moreover, it is related with the black pigment containing the titanium oxide, a electrically conductive agent, and an infrared absorber.

Titanium oxide is a compound mainly composed of titanium-oxygen. In addition to titanium dioxide (TiO ₂ ) used for white pigments and the like, TiO _2-x is generally a compound having a lower oxygen ratio than titanium dioxide. The low order titanium oxide represented is also known. Since low-order titanium oxide has a black color and conductivity, it is blended in resin, paint, ink, cosmetics, etc. as a black pigment, or film, fiber, toner, magnetic recording medium as a conductivity imparting agent Etc. are used in combination. In addition, low-order titanium oxide generally has a particle shape such as a substantially spherical shape, but particles having a special shape such as a needle shape or a plate shape can also be produced. In addition to the property-imparting agent, it is also used as a strength-imparting agent for various resin compositions and rubber compositions.

  Low-order titanium oxide is obtained, for example, by heating a mixture of titanium dioxide and metal titanium powder to a temperature of 800 to 1200 ° C. in an inert gas atmosphere (see Patent Document 1). In addition, in order to prevent deformation of the shape at the time of heating at a high temperature, after depositing high-density silica on the surface of acicular or plate-like titanium dioxide, metallic titanium powder, hydrazine, methylamine, hydrogen, one When heated and reduced with a reducing substance such as carbon oxide, low-order titanium oxide encapsulated in a high-density silica capsule is obtained (see Patent Document 2). Further, Patent Documents 1 and 2 describe heating titanium dioxide at a temperature of about 700 to 1000 ° C. in an ammonia gas atmosphere. The titanium oxynitride thus obtained contains titanium-oxygen-nitrogen. It is a compound that is represented as TiNyOz as a main component and is also referred to as titanium black, and has a black color, conductivity, and the like, similar to low-order titanium oxide. In addition, when a plate-like substrate coated with titanium dioxide is reacted at 400 to 1000 ° C. in a hydrocarbon stream such as methane, ethane, or propane, a plate-like pigment containing carbon is obtained by partially reducing titanium dioxide. (See Patent Document 3).

Japanese Patent Laid-Open No. 2-92824 Japanese Patent No. 3005319 JP-A-5-194875

The value of x represented by TiO _2-x of low-order titanium oxide, that is, it changes so as to exhibit a blue to black color depending on the degree of reduction, but reduction using the metal titanium powder described in Patent Documents 1 and 2 However, since it is a solid reducing agent, there is a problem that the degree of reduction is not uniform and fine adjustment is difficult, and it is difficult to adjust the desired characteristics. Moreover, in order to ensure the uniformity of the degree of reduction, more metal titanium powder than necessary is used, but a lot of oxidized metal titanium powder remains after the reduction reaction, and a means for removing it is necessary. There are also problems such as becoming. In addition, in the use of ammonia gas, although it exhibits a black color, it becomes a compound represented by TiNyOz containing nitrogen and changes to a crystal structure different from TiO ₂ , so the particle shape of the raw material titanium dioxide is difficult to maintain, When the value of y, that is, the degree of nitridation is increased, there is a problem that the particle shape tends to collapse, and there is also a problem that oxidation is easily caused when oxygen is touched. On the other hand, in Patent Document 3, when a plate-like substrate is reacted in a stream of hydrocarbon gas, titanium dioxide coated on the plate-like substrate is partially reduced to obtain a plate-like pigment containing carbon. The color is silver gray or light gray and does not exhibit a desired color.

  The inventors of the present invention have attempted to obtain a low-order titanium oxide having a desired degree of blackness with less uniformity of particle shape and less uniformity in the degree of reduction. When heating at a temperature of 700 to 1200 ° C., the present inventors have found that a desired reduction reaction proceeds and a low-order titanium oxide with little collapse of the particle shape can be obtained.

That is, the present invention provides (1) 0.01 to 5 wt% of carbon element to low-order titanium oxide particles represented by the general formula TiO _2-x and the value of x being in the range of 0.05 to 0.8. Titanium oxide having a lightness L value in the range of 5 to 70, and (2) a method for producing titanium oxide, characterized by heating titanium dioxide to a temperature of 700 to 1200 ° C. in a hydrocarbon gas atmosphere, (3) Lightness L, containing 0.01 to 5% by weight of carbon element in the low-order titanium oxide particles represented by the general formula TiO _2-x and having a value of x in the range of 0.05 to 0.8. Black pigments containing titanium oxide having a value in the range of 8-50.

The titanium oxide of the present invention contains low-order titanium oxide particles in which the value of x represented by the general formula TiO _2-x is in the range of 0.05 to 0.8, and the degree of reduction is Despite being relatively low, it has sufficient blackness because it contains a specific amount of carbon element. For this reason, it can be used for black pigments as an alternative to carbon black, etc., and it can be blended in resins, paints, plastics, cosmetics, paper, etc., or coated on the surface of plates, sheets of metal, plastics, paper, etc. It can be used by forming or kneading.
In addition, since the titanium oxide of the present invention has good absorption of visible light and infrared light, it can also be used as an infrared absorbent. In addition, since it contains low-order titanium oxide particles having a value of x of 0.05 to 0.8 and a carbon element, it has conductivity, and is a conductive agent, charge adjusting agent, toner external additive, electromagnetic shielding. It can also be used as an agent. Furthermore, since the shape such as a needle shape or a plate shape can be maintained, it can be used for a strength imparting agent such as a conductivity imparting agent or a plastic reinforcing agent, and therefore, it can be used for more applications.
Further, the titanium oxide production method of the present invention is a method in which titanium dioxide is heated to a temperature of 700 to 1200 ° C. in a hydrocarbon gas atmosphere, and since a hydrocarbon gas is used, uniformity of the reduction degree can be ensured. Since the reduction degree can be easily adjusted, homogeneous titanium oxide can be produced. Moreover, since it is easy to maintain the shape of the raw material titanium dioxide particles, it is possible to easily and easily produce titanium oxide having various shapes.

The titanium oxide of the present invention contains 0.01 to 5% by weight of carbon element in the low-order titanium oxide particles represented by the general formula TiO _2-x , and the value of x is in the range of 0.05 to 0.8. It is titanium oxide whose brightness L value is the range of 5-70. The titanium oxide of the present invention contains low-order titanium oxides such as Ti ₂ O ₃ , Ti ₃ O ₅ , and Ti ₄ O _7, and all of the particles may be composed of low-order titanium oxide. Alternatively, it may be composed of a mixture or mixed crystal of low-order titanium oxide and titanium dioxide. Preferably, titanium dioxide is present inside the particle, and low-order titanium oxide is present at or near the particle surface. However, it is important that the value of x is in the range of 0.05 to 0.8 when their component composition is represented by the general formula TiO _2-x . The value of x indicates the rate of reduction of oxygen from titanium dioxide, that is, the degree of reduction. As the value of x increases, the reduction proceeds and the rate of oxygen decreases. In the present invention, the value of x is in the range of 0.05 to 0.8. When the value is smaller than 0.05, the blackness and conductivity are not sufficient, and when the value is larger than 0.8, the reduction proceeds too much. Thus, it is difficult to maintain the particle shape, and oxidation stability is a concern. For this reason, the range of preferable x is 0.1-0.7, and a more preferable range is 0.15-0.5. The value of x is obtained by performing thermal analysis (TG-DTA) on the titanium oxide in the atmosphere, and calculating the value of x with the increased amount as an increase in oxygen accompanying oxidation. The titanium oxide of the present invention is mainly composed of titanium and oxygen, and is different from titanium oxynitride (titanium black) mainly composed of titanium-oxygen-nitrogen.

  The titanium oxide of the present invention contains 0.01 to 5% by weight of carbon element with respect to the weight of titanium oxide. The carbon element exists as carbon, amorphous carbon, carbide or hydrocarbon on the surface of the titanium oxide particle or inside the particle, and may be bonded to the titanium atom or attached to the surface of the titanium oxide particle. May be. A preferred form is a state in which titanium dioxide is present inside the particle, and low-order titanium oxide and carbon element are present on or near the particle surface. Moreover, as a carbon element, carbon and amorphous carbon are preferable from the point of blackness. If the content of the carbon element is in the above range, it is preferable because it is effective for maintaining the shape of the low-order titanium oxide particles. If the amount is larger, the dispersibility in a solvent, resin, etc. becomes worse when used as a black pigment. For this reason, a preferable carbon content is about 0.05 to 5.0% by weight, a more preferable range is about 0.05 to 4.0% by weight, and a further preferable range is 0.1 to 3.0% by weight. %. On the other hand, the preferred range of the carbon content may vary depending on the shape of the low-order titanium oxide particles. Specifically, in the low-order titanium oxide having a plate-like shape, particularly a flake shape, which will be described later, when the ratio of the plate-like length to the thickness is 40 or more, the carbon content may be relatively small, 0.01 to About 3.0% by weight is preferable, about 0.05 to 2.0% by weight is more preferable, and about 0.1 to 1.0% by weight is even more preferable. The carbon content of the low-order titanium oxide having an acicular shape is preferably about 0.3 to 5.0% by weight, more preferably about 0.5 to 3.0% by weight when the axial ratio is 7 or more, More preferably, it is about 0.8 to 2.5% by weight. The carbon content is measured and calculated by an organic element (CHN) analyzer.

  Further, the titanium oxide of the present invention has a black color, and in addition to pure black, bluish black, purpleish black, reddish black, brownish black, grayish In addition to black, such as blackish black, other colors may be exhibited. As for the brightness and hue of titanium oxide, 1.5 g of a sample was placed in a glass round cell (Nippon Denshoku Co., Ltd., part No. 1483), and a color difference meter (Nippon Denshoku Color Meter NW-) was placed from the bottom of the cell. The color is measured in 1) and obtained by the Lab color system. The blackness is represented by the lightness index L value of the Lab color system, and the smaller the L value, the stronger the blackness, and the titanium oxide of the present invention can have a blackness of L value of 5 to 70. . If the L value is greater than 70, the blackness is low and it is difficult to use as a black pigment, and if it is less than 5, the particle shape is difficult to maintain, and oxidation stability is also a concern. For this reason, the range of a preferable L value is 8-50, and a more preferable range is 10-35. In addition, the Lab color system a value and b value obtained in the same manner as the L value are indices representing hue saturation, and the redness increases as the a value increases toward the positive side and the greenness increases as the value increases toward the negative side. It shows that it is strong, yellow value is so strong that b value becomes large on the positive side, and blue color is so strong that it becomes large on the negative side. For example, the titanium oxide of the present invention can have a hue having an a value of about −8 to +6 and a b value of about −10 to +8.

  The titanium oxide of the present invention can be appropriately adjusted in particle shape, particle diameter, etc., and can have a needle shape, plate shape, granular shape, substantially spherical shape, spherical shape or the like. Specifically, low-order titanium oxide having an acicular shape has an axial ratio (major axis length / minor axis length) called needle shape, rod shape, spindle shape, fiber shape, column shape, etc. of 2 or more. In addition, any major axis length, minor axis length, axial ratio, etc. can be used, but the major axis length is 0.5 to 10 μm and minor axis length is 0.02 to 1 μm. Is preferable for use in various applications, and those having a major axis length of 0.7 to 8 μm, a minor axis length of 0.02 to 0.8 μm, and an axial ratio of 3 or more are more preferable. The axial ratio is more preferably 5 or more, and most preferably 7 or more. In addition, the low-order titanium oxide having a plate shape includes those having a plate length to thickness ratio of 3 or more, referred to as plate shape, flake shape, etc., and any plate length, thickness, etc. Although it can be used, it is preferable that the plate length is 1 to 50 μm because it is used for various applications. The plate length is 2 to 40 μm, and the ratio of the plate length to the thickness is 4 or more. More preferred. The ratio of the plate length to the thickness is more preferably 10 or more, more preferably 20 or more, further preferably 30 or more, and most preferably 40 or more. In addition, in the low-order titanium oxide such as granular, substantially spherical, spherical, etc., preferably in the range of 0.02-0.5 μm because it has excellent concealing properties, more preferably in the range of 0.02-0.25 μm, A range of 0.03 to 0.2 μm is more preferable, and a range of 0.03 to 0.1 μm is most preferable. The particle size and shape of the low-order titanium oxide and the raw material titanium dioxide can be observed by an electron micrograph, and the particle size is represented by a number average value of 100 particles. The long axis length is defined by the number average value of the longest lengths of 100 acicular titanium dioxide particles, the short axis length is defined by the number average value of the shortest lengths of the particles, and the plate length is 100 pieces. The plate-like titanium dioxide particles are defined by the number average value of (the longest length of the plate pieces + the shortest length of the plate pieces) / 2, and the thickness is defined by the number average thickness of 100 plate pieces.

  Since the titanium oxide of the present invention has a black color, it naturally absorbs visible light (with a wavelength of 400 to 800 nm), and also absorbs infrared light at a wavelength of 800 nm or more. Specifically, using a spectrophotometer (V-570 manufactured by JASCO Corporation), 0.3 g of titanium oxide powder was packed in a cylindrical cell (diameter 16 mm, PSH-001 model manufactured by JASCO Corporation), and visible light-infrared When the reflection spectrum is measured (barium sulfate powder is used as a comparative sample), the reflectance is 50% or less, preferably 40% or less, more preferably 20% or less, and even more preferably 10 in the wavelength range of 800 to 2500 nm. % Or less.

  The titanium oxide of the present invention can be produced by heating titanium dioxide to a temperature of 700 to 1200 ° C. in a hydrocarbon gas atmosphere. If the heating temperature is lower than the above range, reduction is difficult to proceed, and the content of carbon element is reduced, so that it is difficult to obtain the desired titanium oxide. Is liable to occur. For this reason, preferable heating temperature is the range of about 730-1150 degreeC, about 750-1100 degreeC is more preferable, and about 800-1100 degreeC is the most preferable. The heating time varies depending on the amount of titanium dioxide or hydrocarbon gas, and is appropriately set. However, about 0.5 to 20 hours is appropriate for operation, and about 1 to 10 hours is preferable. Moreover, after heating, it may cool, and heating may be repeated repeatedly after that. As the heating device, known devices such as a fluidized bed device, a rotary kiln, a tunnel kiln, and a stationary furnace can be used, and a rotary kiln is particularly preferable. As the hydrocarbon gas, for example, a hydrocarbon gas such as butane, propane, ethane, or methane or a gas obtained by vaporizing volatile hydrocarbons such as octane, heptane, hexane, or pentane can be used. You may mix and use a seed | species or more. In particular, at least one hydrocarbon gas selected from propane, ethane and methane, which are highly reducing, is preferred. Moreover, you may use mixed gas, such as natural gas which has a hydrocarbon as a main component, city gas, and liquefied petroleum gas. Further, the hydrocarbon gas can be diluted with an inert gas such as nitrogen or argon or a reducing gas such as hydrogen.

The titanium dioxide used in the present invention includes titanium dioxide such as hydrated titanium oxide, hydrous titanium oxide and titanium hydroxide in addition to the usual rutile type (R type) and anatase type (A type) titanium dioxide. A compound. Hydrated titanium oxide and hydrous titanium oxide are obtained by, for example, grinding titanium-containing ores such as illuminite ore and titanium slag as necessary, reacting the titanium component with sulfuric acid while dissolving in sulfuric acid, and titanyl sulfate (TiOSO). ₄ ) is generated, left to be classified and filtered, and then obtained by heating and hydrolyzing titanyl sulfate. Titanium hydroxide is obtained by neutralizing titanyl sulfate and titanium chloride with an alkali. Moreover, you may use the titanium dioxide which baked hydrated titanium oxide, hydrous titanium oxide, titanium hydroxide, etc. at the temperature of 200 degreeC or more. The particle shape, particle size, etc. of titanium dioxide can be appropriately selected according to the desired particle shape, particle size, etc. of the obtained low-order titanium oxide, and are acicular, plate-like, granular, substantially spherical, spherical, etc. Shaped ones can be used.

  Acicular titanium dioxide can be manufactured using a known method. Specifically, a known method described in JP-B-6-24977 can be used. For example, in the presence of acicular titanium dioxide nucleus crystals, a titanium compound, an alkali metal compound, and an oxylin compound are added in an amount of 700 to 1000. By baking at a temperature of ° C., titanium dioxide having an acicular shape having a major axis length of 0.5 to 10 μm and a minor axis length of 0.02 to 1 μm can be obtained. As such acicular titanium dioxide, acicular titanium dioxide such as FTL-100, FTL-200, and FTL-300 manufactured by Ishihara Sangyo Co., Ltd. can be used.

  Moreover, plate-like titanium dioxide can be manufactured using the method of a well-known technique. For example, by using the method described in the pamphlet of WO 99/11574 optimally, a plate having a plate-like shape having a plate-like length of 1 to 50 μm and a ratio of the plate-like length to the thickness of 3 or more can be obtained. Specifically, (1) after synthesizing layered metal titanate such as cesium titanate, lithium potassium titanate, potassium magnesium titanate, and then suspending the obtained layered metal titanate in an aqueous solvent A method of adding acid such as hydrochloric acid, sulfuric acid, nitric acid, extracting metal ions to form layered titanic acid, and then baking the layered titanic acid at a temperature of about 400 ° C. or higher to form plate-like titanium dioxide (2 ) After suspending the layered titanic acid produced by the method (1) in an aqueous solvent, adding a basic compound such as an amine compound or an ammonium compound, and swelling the interlayer, the temperature is about 400 ° C. or higher. A method of firing into plate-like titanium dioxide, (3) peeling the layers by shaking titanic acid swollen by the method of (2) above to obtain a sheet-like titanate compound, Then (4) A sheet-like titanium dioxide suspension obtained by the method (3) above is spray-dried to obtain a sheet. A hollow fine powder bonded with a titanic acid compound, followed by dry pulverization and firing at a temperature of about 400 ° C. or higher to obtain plate-like titanium dioxide, (5) by the method of (3) above The obtained sheet-like titanium dioxide suspension is freeze-dried to obtain a porous gel bonded with the sheet-like titanate compound, and then subjected to dry pulverization and baking at a temperature of about 400 ° C. or more to form a plate A method using titanium dioxide or the like can be used.

  As titanium dioxide, reduction is difficult to proceed when water is present during reduction. Therefore, it is preferable to use hydrated titanium oxide, hydrous titanium oxide, titanium dioxide having less water than titanium hydroxide, and anatase than rutile type. Type titanium dioxide is more preferred because it is more easily reduced. For this reason, the raw material is calcined at a temperature of 400 ° C. or higher in the preparation of titanium dioxide, or hydrated titanium oxide, hydrous titanium oxide or titanium hydroxide in an atmosphere of air or oxygen-containing gas or nitrogen, argon, etc. It is preferable to use one previously calcined at a temperature of 400 ° C. or higher in an inert gas atmosphere because it is possible to further prevent the particle shape from collapsing, and a temperature of about 700 to 1000 ° C. is more preferable. As such titanium dioxide, acicular titanium dioxide such as FTL-100, FTL-200, and FTL-300 manufactured by Ishihara Sangyo Co., Ltd., and plate-like titanium dioxide such as NSTB-1 manufactured by Ishihara Sangyo Co., Ltd. can be used.

  After producing titanium dioxide, if necessary, dry pulverization may be performed by a known method, or after slurrying, wet pulverization, dehydration, drying, and dry pulverization may be performed. Moreover, you may coat | cover the surface of titanium dioxide with at least 1 sort (s) chosen from an inorganic compound and an organic compound for the purpose of preventing collapse of a particle shape. Examples of the inorganic compound include an aluminum compound, a silicon compound, a zirconium compound, a tin compound, a titanium compound, and an antimony compound. Examples of the organic compound include a polyhydric alcohol, an alkanolamine or a derivative thereof, an organosilicon compound, Higher fatty acids or metal salts thereof, organometallic compounds and the like can be mentioned. When coating the surface of titanium dioxide with an inorganic compound or an organic compound, use a known method such as a wet method or a dry method, for example, when dry pulverizing titanium dioxide, when slurrying, or when wet pulverizing Can do.

Thus, the low-order titanium oxide particles represented by the general formula TiO _2-x and having a value of x in the range of 0.05 to 0.8 contain 0.01 to 5% by weight of carbon element. Titanium oxide having a lightness L value in the range of 5 to 70 can be produced, and carbon dioxide can be produced on the surface of the low-order titanium oxide particles. By appropriately adjusting the heating conditions and the like, Low-order titanium oxide and carbon element can be present on the particle surface. After producing titanium oxide, if necessary, dry pulverization may be performed by a known method, or after slurrying, wet pulverization, dehydration, drying, and dry pulverization may be performed. For the dry pulverization, an impact pulverizer such as a hammer mill and a pin mill, a grinding pulverizer such as a roller mill and a pulverizer, and an airflow pulverizer such as a jet mill can be used. For wet pulverization, a vertical sand mill, a horizontal sand mill, or the like can be used. For drying, a band heater, a batch heater, a spray dryer or the like can be used.

  The surface of the titanium oxide particles of the present invention has at least one selected from an inorganic compound and an organic compound for the purpose of improving the affinity with a resin binder, the stability over time during storage of the paint, and improving the productivity. Seeds may be coated. Examples of the inorganic compound include an aluminum compound, a silicon compound, a zirconium compound, a tin compound, a titanium compound, an antimony compound, and the like. The above inorganic compounds may be mixed and coated and used in combination. More preferably, these inorganic compounds are at least one selected from oxides, hydroxides, hydrated oxides, and phosphates. Examples of organic compounds include polyhydric alcohols, alkanolamines or derivatives thereof, organosilicon compounds, higher fatty acids or metal salts thereof, and organometallic compounds. Specifically, for example, (1) polyhydric alcohol includes trimethylolethane, trimethylolpropane, tripropanolethane, pentaerythritol and the like. (2) Examples of the alkanolamine include triethanolamine and tripropanolamine. (3) Examples of organosilicon compounds include: (a) polysiloxanes (dimethylpolysiloxane, methylhydrogenpolysiloxane, methylphenylpolysiloxane, dimethylpolysiloxanediol, alkyl-modified silicone oil, alkylaralkyl-modified silicone oil, amino-modified silicone) Oil, both-end amino-modified silicone oil, epoxy-modified silicone oil, both-end epoxy-modified silicone oil, fluorine-modified silicone oil, etc.), (b) organosilanes (n-butyltriethoxysilane, isobutyltrimethoxysilane, n-hexyl) Trimethoxysilane, n-hexyltriethoxysilane, n-octyltrimethoxysilane, n-octyltriethoxysilane, n-decyltrimethoxysilane, n-octadecyl Non-reactive silanes such as methoxysilane, alkylsilanes such as n-octadecylmethyldimethoxysilane, phenylsilanes such as phenyltriethoxysilane, fluorosilanes such as trifluoropropyltrimethoxysilane, and aminopropyltriethoxysilane N- (β-aminoethyl) -γ-aminopropyltriethoxysilane, N-phenyl-γ-aminopropyltrimethoxysilane, vinyltrimethoxysilane, vinyltriethoxysilane, vinyltrichlorosilane, γ-glycidoxypropyl Silane coupling agents such as trimethoxysilane, methacryloxypropyltrimethoxysilane, and β- (3,4 epoxycyclohexyl) ethyltrimethoxysilane). (4) Examples of higher fatty acids include stearic acid and lauric acid, and examples of metal salts thereof include magnesium salts and zinc salts. (5) Examples of organometallic compounds include isopropyl triisostearoyl titanate, isopropyl tris (dioctyl pyrophosphate) titanate, tetra (2,2-diallyloxymethyl-1-butyl) bis (ditridecyl) phosphite titanate, bis (dioctyl) Pyrophosphate) Oxyacetate titanate, bis (dioctylpyrophosphate) ethylene titanate, titanium coupling agents such as isopropyltri (N-amidoethyl / aminoethyl) titanate, aluminum coupling agents such as acetoalkoxyaluminum diisopropylate, zirconium Zirconium compounds such as tributoxyacetylacetonate and zirconium tributoxy systemate are listed. These can be coated alone or in combination of two or more. The coating amount can be appropriately set, but is preferably in the range of about 0.01 to 30% by weight, more preferably in the range of about 0.05 to 10% by weight, and about 0.1 to 5% by weight with respect to titanium oxide. The range of is more preferable. When coating the surface of titanium oxide with an inorganic compound or an organic compound, use a known method such as a wet method or a dry method, for example, when dry pulverizing titanium oxide, when slurrying, or when wet pulverizing Can do. When performing the surface treatment by a wet method, it is preferable to wet-grind titanium oxide before or during the treatment. Further, the surface treatment by the wet method can be carried out in either an aqueous system or a solvent system, but the aqueous system is preferable in terms of environment, cost, and equipment. However, when processing in an aqueous system, especially when performing wet pulverization, low-order titanium oxide is slightly oxidized due to the influence of water itself or dissolved oxygen in the water, so hydrazine, sodium borohydride, formaldehyde, tartaric acid, It is preferable to perform wet pulverization in the presence of a reducing agent such as glucose, sodium hypophosphite, or NN-diethylglycine sodium.

  Titanium oxide of the present invention has excellent shielding performance (light shielding performance) and black performance when blended into a resin such as paint, ink or film, as a black pigment, as an infrared absorber or as a conductive agent. Or it can be set as the resin composition using electroconductive performance. In this resin composition, the titanium oxide of the present invention is blended in an arbitrary amount, preferably 20% by weight or more, in addition to the composition-forming material used in each field, and various additives. You may mix. In the case of paints and inks, coating film forming materials or ink film forming materials, solvents, dispersants, pigments, fillers, thickeners, flow control agents, leveling agents, curing agents, crosslinking agents, curing catalysts Etc. Examples of coating film forming materials include organic components such as acrylic resins, alkyd resins, urethane resins, polyester resins, and amino resins, and inorganic components such as organosilicates and organotitanates. In this case, urethane resin, acrylic resin, polyamide resin, vinyl acetate resin, chlorinated propylene resin and the like can be used. Various materials such as thermosetting resin, room temperature curable resin, and ultraviolet curable resin can be used for these coating film forming material and ink film forming material. When a resin is used, a photopolymerization initiator or photosensitizer is blended, and UV light is applied and cured after application, a coating with excellent hardness and adhesion can be obtained without applying a thermal load to the substrate. Therefore, it is preferable. In the case of plastic moldings, the titanium oxide of the present invention can be used for plastics, pigments, dyes, dispersants, lubricants, antioxidants, ultraviolet absorbers, light stabilizers, antistatic agents, flame retardants, bactericides, and the like. Kneaded together and molded into any shape such as film. Plastics include thermoplastic resins such as polyolefin resin, polystyrene resin, polyester resin, acrylic resin, polycarbonate resin, fluororesin, polyamide resin, cellulose resin, and polylactic acid resin, and thermosetting resins such as phenol resin and urethane resin. Can be used.

  Hereinafter, the present invention will be described in more detail with reference to Examples and Comparative Examples, but the present invention is not limited to these Examples.

Example 1
Acicular titanium dioxide (Ishihara Sangyo FTL-100, a long axis length of 1.7 μm, a short axis length of 0.13 μm, a rutile type titanium dioxide with an axial ratio of 13) a quartz tube with an inner diameter of 7.5 cm And heated to 900 ° C., then, a mixed gas of propane gas 5 ml / min and nitrogen gas 3 liter / min was flowed, and the temperature of 900 ° C. was maintained for 2 hours to obtain the titanium oxide of the present invention (sample A )

Example 2
In Example 1, the titanium oxide (sample B) of this invention was obtained like Example 1 except heating at 1000 degreeC.

Example 3
Plate-like titanium dioxide (NSTB-1, manufactured by Ishihara Sangyo Co., Ltd., plate length is 15 μm, thickness is 0.2 μm, the ratio of plate length to thickness is 75. Anatase-type titanium dioxide partially mixed with rutile-type titanium dioxide Is charged in a quartz tube with an inner diameter of 7.5 cm and heated to 1100 ° C., then a mixed gas of propane gas 20 ml / min and nitrogen gas 3 liter / min is flowed, and the temperature of 1100 ° C. is maintained for 1 hour. Thus, titanium oxide (sample C) of the present invention was obtained.

Comparative Example 1
In Example 1, after heating to 1000 ° C., a mixed gas of hydrogen and nitrogen (75% by volume of hydrogen, 25% by volume of nitrogen) was flowed at 2 liters / minute, and the temperature at 1000 ° C. was maintained for 5 hours. Sample D) was obtained.

Comparative Example 2
Titanium dioxide (FTL-100) used in Example 1 was used as Comparative Sample E.

Comparative Example 3
Titanium dioxide (NSTB-1) used in Example 5 was used as Comparative Sample F.

Table 1 shows the compositions and characteristics of Samples A to F obtained in Examples and Comparative Examples. Also, powder X-ray diffraction patterns of Samples A to F are shown in FIGS. 1 to 6, electron micrographs of Samples A, C, and D to F are shown in FIGS. 7 to 11, and Sample A for laser Raman spectroscopy under the following conditions. 12-14 show the Raman spectra of B, E, and FIG. 15 shows the results of measuring the visible light-infrared reflectance of Samples A, B. From these results, it can be seen that the titanium oxide of the present invention is black and maintains the particle shape of the raw material titanium dioxide. Moreover, from the results of powder X-ray diffraction of samples A to E, peaks of low-order titanium oxides such as rutile titanium dioxide, Ti ₂ O ₃ , Ti ₃ O _{5, and} Ti ₄ O ₇ can be confirmed. From the results, it was confirmed that amorphous carbon was generated on the surface of the sample, and it was found that carbon element was present on the surface of the low-order titanium oxide particles. It was also found that the titanium oxide of the present invention has low visible light and infrared reflectance.

Laser Raman spectroscopy (1) Equipment: T-64000 (Horiba Jobin Yvon)
(2) Conditions:
Measurement mode: Macro Raman Beam diameter: 100 μm
Light source: Ar ⁺ laser / 514.5nm
Laser power: 10mW
Diffraction grating: Spectrograph 600gr / mm
Dispersion: Single 21A / mm
Slit: 100 μm
Detector: CCD (Jobin Yvon 1024 × 256)

  The titanium oxide of the present invention is used as a black pigment or infrared absorber by blending it with resin, plastic, paint, ink, cosmetics, paper and the like. Moreover, it can also mix | blend and use for example, glass, a lens, a film, etc. as an optical member which shields visible light and infrared rays. Further, the titanium oxide of the present invention is used as a conductive agent, a charge adjusting agent, a toner external additive, and an electromagnetic shielding agent in a film, fiber, toner, magnetic recording medium, photographic paper and the like. Furthermore, since the shape such as a needle shape or a plate shape can be maintained, it can be used for a strength imparting agent such as a plastic reinforcing agent.

2 is a powder X-ray diffraction pattern of Sample A obtained in Example 1. FIG. 3 is a powder X-ray diffraction pattern of Sample B obtained in Example 2. FIG. 3 is a powder X-ray diffraction pattern of Sample C obtained in Example 3. FIG. 3 is a powder X-ray diffraction pattern of Sample D obtained in Comparative Example 1. 4 is a powder X-ray diffraction pattern of Sample E obtained in Comparative Example 2. 4 is a powder X-ray diffraction pattern of Sample F obtained in Comparative Example 3. 2 is an electron micrograph of Sample A obtained in Example 1. 4 is an electron micrograph of Sample C obtained in Example 3. 4 is an electron micrograph of Sample D obtained in Comparative Example 1. 4 is an electron micrograph of Sample E obtained in Comparative Example 2. 6 is an electron micrograph of Sample F obtained in Comparative Example 3. It is a Raman spectrum by the laser Raman spectroscopy of the sample A obtained in Example 1. It is a Raman spectrum by the laser Raman spectroscopy of the sample B obtained in Example 2. It is a Raman spectrum by the laser Raman spectroscopy of the sample E obtained in the comparative example 2. 3 is a graph showing a visible light-infrared reflection spectrum of Sample A obtained in Example 1. FIG. 4 is a graph showing a visible light-infrared reflection spectrum of Sample B obtained in Example 2. FIG.

Claims (14)

A low-order titanium oxide particle represented by the general formula TiO _{2-x and} having a value of x in the range of 0.05 to 0.8 contains 0.01 to 5% by weight of carbon element, and a lightness L value of 5 Titanium oxide in the range of ~ 70. The titanium oxide according to claim 1, wherein a carbon element is present on the surface of the low-order titanium oxide particles. The titanium oxide according to claim 1, which has a needle-like shape having a major axis length of 0.5 to 10 µm and a minor axis length of 0.02 to 1 µm. The titanium oxide according to claim 1, which has a plate shape having a plate length of 1 to 50 µm and a ratio of the plate length to the thickness of 3 or more. Titanium dioxide is heated to a temperature of 700 to 1200 ° C. in a hydrocarbon gas atmosphere, and is represented by the general formula TiO _2-x , the value of x being in the range of 0.05 to 0.8 The manufacturing method of the titanium oxide whose brightness L value is the range of 5-70 which contains 0.01-5 weight% of carbon elements in a sub-titanium oxide particle. 6. The method for producing titanium oxide according to claim 5, wherein titanium dioxide is heated to a temperature of 700 to 1200 ° C. in a hydrocarbon gas atmosphere so that carbon elements are present on the surface of the low-order titanium oxide particles. 6. The method for producing titanium oxide according to claim 5, wherein titanium dioxide having an acicular shape having a major axis length of 0.5 to 10 [mu] m and a minor axis length of 0.02 to 1 [mu] m is used. 6. The method for producing titanium oxide according to claim 5, wherein titanium dioxide having a plate shape having a plate length of 1 to 50 [mu] m and a ratio of the plate length to the thickness of 3 or more is used. 6. The method for producing titanium oxide according to claim 5, wherein at least one hydrocarbon gas selected from propane, ethane and methane is used. The method for producing titanium oxide according to claim 5, wherein titanium dioxide baked at a temperature of 400 ° C or higher is used in the preparation of titanium dioxide. A low-order titanium oxide particle represented by the general formula TiO _{2-x and} having a value of x in the range of 0.05 to 0.8 contains 0.01 to 5% by weight of carbon element, and a lightness L value of 8 A black pigment containing titanium oxide in the range of ˜50. The black pigment containing titanium oxide according to claim 11, wherein a carbon element is present on the surface of the low-order titanium oxide particles. The electrically conductive agent containing the titanium oxide as described in any one of Claims 1-4. The infrared absorber containing the titanium oxide as described in any one of Claims 1-4.

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