JP2011190164A - Composite containing tin oxide and tin compound with oxygen deficiency and production method thereof - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a composite containing tin oxide and a tin compound with oxygen deficiency. <P>SOLUTION: The composite containing tin oxide and a tin compound with oxygen deficiency such as of metal tin microcrystals is produced by heating tin oxide to a temperature of 400-700°C in the presence of a compound containing nitrogen such as urea in order to reduce a part of tin oxide. The composite has characteristics of tin oxide and the tin compound with oxygen deficiency, and, for example, has an excellent conductivity originated from the tin compound with oxygen deficiency such as metal tin microcrystals. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a composite containing tin oxide and an oxygen-deficient tin compound and a method for producing the same. Moreover, it is related with the particle | grains containing the said composite, and its manufacturing method. Furthermore, it is related with the dispersion containing the said composite or the particle | grains containing a composite, a coating composition, a resin composition, a coating film, and a molded article.

Tin oxide is an inorganic oxide material excellent in semiconductivity, visible light transmittance, conductivity, near-infrared shielding property, thermal conductivity, and the like, and is a material that is chemically and thermally stable. Specifically, tin dioxide itself has semiconductivity and is used as a semiconductor or a photocatalyst. Fine particulate tin dioxide has visible light permeability and is used as a transparent filler. Further, when different atoms such as antimony, phosphorus, fluorine, niobium, and tungsten are doped inside the tin dioxide particles, they have conductivity, near-infrared shielding properties, and the like, and are used as conductive fillers. Further, a SnO _2-z compound in which a slight oxygen deficiency is generated from the stoichiometric ratio of tin dioxide SnO ₂ and further tin monoxide SnO are also known.
Furthermore, tin oxide is used as a composite filler that covers the surface of substrate particles such as titanium oxide, zinc oxide, silica, alumina, barium sulfate, and mica, and has both the performance of tin oxide and the properties of substrate particles. . For example, titanium dioxide particles coated with tin dioxide doped with different atoms such as antimony, phosphorus, fluorine, niobium and tungsten are used as white conductive fillers.

  Such tin oxide is used, for example, by mixing in plastics, rubber, or the like as a filler in order to impart conductivity or by blending it in a coating film formed on a substrate such as a sheet or plate. Specifically, tin dioxide fine particles doped with different atoms such as antimony, phosphorus, fluorine, niobium, and tungsten are extremely low resistance, low haze, and have a transparent conductive film with high adhesion to the substrate and high film strength. Since it can be manufactured, it is used for anti-static and electromagnetic field shielding of displays such as OA devices, and is also used for transparent electrodes of display devices such as touch panels and liquid crystal displays.

Tin dioxide is produced by firing a precipitate obtained by reacting a tetravalent tin salt aqueous solution with an alkali solution. For example, in Patent Document 1, a reaction between a tetravalent tin salt aqueous solution and an alkali solution is performed in a pH range of 0.5 to 4 to form a tin-containing precipitate, and then fired in a temperature range of 400 to 1200 ° C. It describes what to do. In addition, tin dioxide doped with antimony is added with a tetravalent tin salt aqueous solution and an alkaline aqueous solution in parallel, and neutralized while maintaining the pH of the neutralization reaction solution at 3 or higher to produce tin oxide water. Then, a solution of antimony chloride and an aqueous alkali solution are added in parallel to the product water, and neutralized while maintaining the pH of the neutralization reaction solution at 3 or more to obtain a surface of the product. A method is known in which antimony oxide hydrate is formed and then fired (see Patent Document 2). In addition, it is known that SnO _2-z having oxygen deficiency is produced by hydrogen reduction of tin dioxide.

JP 2002-029744 A Japanese Patent No. 3647929

As described above, tin oxides having various compositions are known, but further improvement in the performance of them is required. For example, tin oxide doped with antimony as a conductive filler is required to be tin oxide not doped with antimony because of toxicity concerns. Further, tin dioxide doped with phosphorus tends to be unstable in conductivity. SnO _{2-z in} which oxygen deficiency has occurred has problems such as difficulty in controlling the reaction due to hydrogen reduction, and the degree of oxygen deficiency is not stable, leading to unstable conductivity.

  Therefore, when the present inventors heated tin oxide in the presence of a nitrogen-containing compound in order to improve the performance of tin oxide, a part of the tin oxide was reduced and further tin such as metal tin microcrystals was further reduced. An oxygen deficient compound is produced, and a composite containing tin oxide and an oxygen deficient tin compound is obtained. It has been found that this compound has excellent conductivity and has excellent stability. Completed the invention.

That is, the present invention
(1) Tin oxide represented by SnO _2-x (where x is a real number satisfying 0 ≦ x <2) and oxygen-deficient tin compound represented by SnO _2-xy (where x is And y is a real number satisfying 0 <y ≦ 2-x).
(2) particles containing the composite,
(3) Tin oxide represented by SnO _2-x that heats tin oxide represented by SnO _2-x (wherein x is a real number satisfying 0 ≦ x <2) in the presence of a nitrogen-containing compound. (Wherein x is a real number satisfying 0 ≦ x <2) and an oxygen-deficient tin compound represented by SnO _2-xy (wherein x is as described above and y is 0 <y ≦ A real number satisfying 2-x)).
(4) A dispersion, a coating composition, a resin composition, a molded article containing the composite of (1) or particles of (2),
(5) A coating film formed by applying the above dispersion or coating composition.

The composite of the present invention comprises a tin oxide represented by SnO _2-x (wherein x is a real number satisfying 0 ≦ x <2) and an oxygen-deficient tin compound represented by SnO _2-xy (formula Wherein x is as described above, and y is a real number satisfying 0 <y ≦ 2-x.), And thus has both the performance of tin oxide and the performance of an oxygen-deficient tin compound. It is a stable material both thermally and thermally. For example, it has excellent conductivity due to an oxygen-deficient tin compound such as metal tin microcrystal, and its stability is also high. In addition, improvements in near-infrared shielding performance, heat conduction performance, and the like are expected.
Moreover, it can be used as particles containing the composite, and the composite can be used by coating the surface of the base particles.
The method for producing a composite of the present invention is a method for reducing tin oxide in the presence of a nitrogen-containing compound such as a urea compound, which does not require a large-scale apparatus and uses relatively inexpensive raw materials. Further, it can be produced industrially advantageously, and without using an explosive or self-combustible gas such as hydrogen, ammonia or carbon monoxide.
Furthermore, the present invention is a dispersion, a coating composition, a resin composition, a molded product, a coating film, or the like containing the composite or the particles containing the composite, and the performance of tin oxide and the oxygen-deficient tin compound. And can be used to give

The composite of the present invention comprises a tin oxide represented by SnO _2-x (wherein x is a real number satisfying 0 ≦ x <2) and an oxygen-deficient tin compound represented by SnO _2-xy (formula Wherein x is as described above, and y is a real number satisfying 0 <y ≦ 2-x. Tin oxide contained in the composite is represented by SnO _2-x , where x is a real number satisfying 0 ≦ x <2, and tin oxide, tin monoxide, a tin oxide compound in which oxygen deficiency occurs, These include compounds doped with different atoms such as antimony, phosphorus, fluorine, niobium and tungsten. In particular, chemically and thermally stable tin dioxide itself is preferred, which is preferably tin dioxide not doped with antimony. The oxygen-deficient tin compound contained in the composite is represented by SnO _2-xy , where x is as described above, y is a real number satisfying 0 <y ≦ 2-x, A compound in which oxygen vacancies are further generated than tin oxide represented by SnO _2-x, which may be reduced to metallic tin (zero-valent state) and doped with different atoms such as antimony, phosphorus, niobium, and tungsten It may be what you did. The above tin oxide and oxygen-deficient tin compound can be confirmed by X-ray diffraction, and a compound containing both is called a composite. As for the form of the composite, one of tin oxide and oxygen-deficient tin compound is a core particle, and the other particle is coated on the surface, or one of tin oxide particle and oxygen-deficient tin compound particle is layered And the like. The shape of these particles may be any shape such as an isotropic shape such as a spherical shape or a lump shape, an anisotropic shape such as a needle shape, a rod shape, a plate shape, or a flake shape. Moreover, it is not necessary to confirm any bonding state between the tin oxide and the oxygen-deficient tin compound, and a mixture of tin oxide and the oxygen-deficient tin compound may be used. It is preferable to contain an oxygen-deficient tin compound on the surface and / or inside of the tin oxide particles, more preferably present in the vicinity of the surface of the tin oxide particles, and metal tin microcrystals in the vicinity of the surface of the tin oxide particles. Is more preferable. By setting it as such a state, the performance of an oxygen deficient tin compound can be further utilized.
Further, a composite obtained by heating tin oxide in the presence of a nitrogen-containing compound such as a urea compound is more preferable, and the composite obtained in this way may contain nitrogen element.

  The content of the oxygen-deficient tin compound can be appropriately set depending on the application, and is preferably about 0.1 to 1000% by weight, more preferably 1 to 500% by weight, based on the weight of tin oxide. As a conductive filler, about 5-200 weight% is preferable with respect to the weight of a tin oxide, and 10-100 weight% is more preferable. The size of the composite can be appropriately set according to the use, but in order to ensure transparency, fine particles are preferable, about 0.005 to 10 μm is more preferable, and 0.01 to 1 μm is still more preferable. In addition, on the particle surface of the composite, from the viewpoint of dispersibility in a solvent, affinity of a resin, etc., conventional surfactants, coupling agents, carboxylic acids, polyols, amines, organic compounds such as amines, siloxanes, aluminum, You may coat | cover the inorganic compound of oxides and hydrous oxides, such as silicon, zirconium, and titanium. The amount of the coating can be appropriately set, but is preferably about 1 to 100% by weight with respect to the composite.

  The particles of the present invention contain a composite containing tin oxide and an oxygen-deficient tin compound. A preferable form is tin oxide particles containing an oxygen-deficient tin compound on the surface and / or inside as described above. In another preferred embodiment, the surface of the substrate particle is coated with the composite, and a more preferred embodiment is a surface of the substrate particle containing tin oxide particles containing an oxygen-deficient tin compound on the surface and / or inside. Is coated. As the base particles, any particles can be used as long as they can cover the composite. For example, titanium oxide, zinc oxide, silica, alumina, barium sulfate, mica and the like can be used. The coating amount of the composite can be appropriately set according to the use, and is preferably about 0.1 to 500% by weight, more preferably 1 to 250% by weight with respect to the weight of the base particles. As a conductive filler, about 1-500 weight% is preferable with respect to the weight of a base particle, and 10-100 weight% is more preferable. Although the magnitude | size of a base particle can be suitably set according to a use, about 0.005-10 micrometers is more preferable for using as a filler, and 0.01-1 micrometer is still more preferable. The obtained base particles may contain nitrogen element when heat-treated in the presence of a nitrogen-containing compound described later. Further, on the surface of the substrate particles of the present invention, from the viewpoint of dispersibility in a solvent, affinity of a resin, etc., conventional surfactants, coupling agents, carboxylic acids, polyols, amines, organic compounds such as siloxane, You may coat | cover the inorganic compound of oxides and hydrated oxides, such as aluminum, silicon, zirconium, and titanium. The amount of these coatings can be appropriately set, but is preferably about 1 to 100% by weight with respect to the base particles.

In the method for producing a composite of the present invention, tin oxide represented by SnO _2-x (wherein x is a real number satisfying 0 ≦ x <2) is heated in the presence of a nitrogen-containing compound. As the nitrogen-containing compound, any organic compound containing nitrogen in the molecule that can be decomposed by heating to reduce a part of tin oxide to an oxygen-deficient tin compound can be used. For example, ammonia compounds such as ammonium carbonate and ammonium hydroxide, amine compounds such as alkylamines and urea compounds, amide compounds such as acid amides, and the like can be used, and urea compounds having a strong reducing power are more preferable.

  The urea compound used in the present invention is a compound represented by the following structural formula (Chemical Formula 1) or a compound produced by decomposition of urea contained in the following Structural Formula (Chemical Formula 1) upon heating, such as a compound having a triazine ring Cyanuric acid, melamine, or the like, or melem or melon produced by heating melamine can be used. In addition, as the urea compound used in the present invention, one in which sulfur is bonded instead of oxygen double-bonded to carbon described in the following structural formula (Chemical Formula 1) (for example, thiourea) can be used.

  In Structural Formula (1), R 1, R 2, R 3 and R 4 are each independently a hydrogen atom; an alkyl group, preferably an alkyl group having 1 to 6 carbon atoms, such as methyl, ethyl, propyl, butyl, etc .; an alkenyl group Preferably an alkenyl group having 2 to 6 carbon atoms such as vinyl and allyl; an aryl group, preferably an aryl group having 6 to 10 carbon atoms such as phenyl; a primary amino group; an alkylamino group, preferably 1 to 6 alkylamino groups, such as methylamino, ethylamino and the like; or dialkylamino groups, preferably dialkylamino groups having 2 to 6 carbon atoms, such as dimethylamino, diethylamino and the like. R1, R2, R3 and R4 may be linked to form a 5- to 6-membered ring. These groups may further have a substituent.

  Examples of substituents include halogen atoms, alkyl groups (including cycloalkyl groups and bicycloalkyl groups), alkenyl groups (including cycloalkenyl groups and bicycloalkenyl groups), alkynyl groups, aryl groups, heterocyclic groups, and cyano groups. , Hydroxyl group, nitro group, carboxyl group, alkoxy group, aryloxy group, silyloxy group, heterocyclic oxy group, acyloxy group, carbamoyloxy group, alkoxycarbonyloxy group, aryloxycarbonyloxy, amino group (including anilino group) , Acylamino group, aminocarbonylamino group, alkoxycarbonylamino group, aryloxycarbonylamino group, sulfamoylamino group, alkyl and arylsulfonylamino group, mercapto group, alkylthio group, arylthio group, heterocycle O group, sulfamoyl group, sulfo group, alkyl and arylsulfinyl group, alkyl and arylsulfonyl group, acyl group, aryloxycarbonyl group, alkoxycarbonyl group, carbamoyl group, aryl and heterocyclic azo group, imide group, phosphino group, phosphinyl Examples include groups, phosphinyloxy groups, phosphinylamino groups and silyl groups.

  Of these, urea (melting point: 133 ° C.), thiourea (melting point: 182 ° C.), biuret (melting point: 186-189 ° C.), and cyanuric acid (melting point: 320-360 ° C.) are preferable in terms of ease of handling. Of these, urea and thiourea are more preferable because they are inexpensive and can be obtained stably. Among these, when thiourea is used, it is preferable in that the conductivity imparting effect is higher than that of urea. On the other hand, when urea is used, it is preferable in that the whiteness of the tin oxide particles obtained can be kept high compared to thiourea.

  On the other hand, from the viewpoint of imparting conductivity, a compound having a triazine ring in the structure is preferable, such as cyanuric acid and melamine (melting point: 354 ° C.), and among them, melamine is preferable. Those having the above triazine ring in the structure have a melting point as high as 300 ° C. or higher, and the temperature of the melt is close to the temperature range in the heating step described later. For this reason, it is considered that the compound having a triazine ring is likely to decompose while covering the surface of the tin oxide particles in the melt state, and the reduction reaction of tin oxide is likely to occur.

  For this reason, the urea compound preferably has a melting point of 100 ° C. or higher, more preferably 150 ° C. or higher, still more preferably 200 ° C. or higher, and particularly preferably 300 ° C. or higher.

The tin oxide used in the present invention is represented by SnO _2-x , where x is a real number satisfying 0 ≦ x <2, and tin dioxide, tin monoxide, a tin oxide compound in which oxygen deficiency occurs, A compound doped with a different atom such as antimony, phosphorus, fluorine, niobium, or tungsten can be used. In particular, chemically and thermally stable tin dioxide itself is preferred, which is preferably tin dioxide not doped with antimony. For example, a tin (IV or II) compound, an alkali, and a dopant as necessary are mixed and heated to 50 ° C. or higher to hydrolyze the tin compound. As the tin compound, a water-soluble tin compound is preferable, and tin chloride is more preferable. As the alkali, alkali hydroxides such as sodium hydroxide, potassium hydroxide and lithium hydroxide, alkali carbonates such as sodium carbonate, ammonium compounds such as ammonium carbonate, ammonia and the like can be used. Sodium oxide is preferred. The tin oxide obtained by hydrolysis may be calcined in advance, and the calcining temperature can be appropriately set. Specifically, the temperature is preferably 400 to 700 ° C, more preferably 550 ° C to 700 ° C. Preferably, 600 ° C to 700 ° C is more preferable.

When tin oxide is heated in the presence of the nitrogen-containing compound, a part of tin oxide is reduced by the nitrogen-containing compound, and a composite containing tin oxide and an oxygen-deficient tin compound can be produced. As described above, tin oxide is represented by SnO _2-x , where x is a real number satisfying 0 ≦ x <2, and tin dioxide, tin monoxide, a tin oxide compound in which oxygen deficiency has occurred, and those Further, a compound doped with a different atom such as antimony, phosphorus, fluorine, niobium, or tungsten may be used. The oxygen-deficient tin compound is represented by SnO _2-xy , where x is as described above, y is a real number satisfying 0 <y ≦ 2-x, and the SnO _2-x Is a compound in which oxygen deficiency is further generated than tin oxide, which may be reduced to metallic tin (zero-valent state), and doped with different atoms such as antimony, phosphorus, niobium, tungsten, etc. Also good. Specific methods include mixing and heating tin oxide and a nitrogen-containing compound, or adding a solid, liquid, or gas of a nitrogen-containing compound when heating the tin oxide. A method in which tin and a nitrogen-containing compound are mixed and heated is simple and preferable. Arbitrary methods can be used for mixing the tin oxide and the nitrogen-containing compound. Specifically, either dry mixing in a powder state or wet mixing in a slurry state may be used, and stirring is performed. A conventional mixer such as a mixer can be used. In addition, a nitrogen-containing compound can be mixed when tin oxide is pulverized, dried, granulated, or molded using various pulverizers, spray dryers, granulators, molding machines, and the like. Further, the nitrogen-containing compound may be dissolved in a suitable solvent and then mixed with tin oxide. The mixing ratio of the nitrogen-containing compound can be appropriately set, but is preferably about 0.1 to 1000% by weight and more preferably 1 to 500% by weight with respect to tin oxide. On the other hand, in order to add a nitrogen-containing compound during the heating of tin oxide, it is preferable to appropriately add a nitrogen-containing compound such as a urea compound in a heating furnace in a solid, liquid, or gas state. For example, the urea compound can be added in a solid or liquid state.

  The heating of the tin oxide is performed under the condition that the mixed or added nitrogen-containing compound is decomposed and a part of the tin oxide is reduced to the oxygen-deficient tin compound. The heating atmosphere may be air or a conventionally known reducing gas atmosphere such as hydrogen gas, ammonia gas, or hydrazine gas, but an inert gas atmosphere such as nitrogen gas or argon gas is preferable. The heating temperature can be appropriately set as long as the reduction reaction proceeds. Specifically, the temperature is preferably 400 to 700 ° C, more preferably 550 to 700 ° C, and still more preferably 600 to 700 ° C. The heating time can also be set as appropriate, but it is preferably 1 hour or longer, more preferably 3 hours or longer, and even more preferably 5 hours or longer in order to sufficiently decompose the nitrogen-containing compound. For heating, a known heating furnace such as a fluidized furnace, a stationary furnace, a rotary kiln, or a tunnel kiln can be used. After heating, water may be removed to remove impurities or classify coarse particles. Depending on the degree of sintering, impact crusher such as hammer mill, pin mill, roller mill, pulverizer, crusher, etc. The dry pulverization may be performed using a compression pulverizer such as a grinding pulverizer, a roll crusher or a jaw crusher, or an airflow pulverizer such as a jet mill. Further, the obtained composite particles may be subjected to a surface treatment, such as conventional surfactants, coupling agents, organic compounds such as carboxylic acids, polyols, amines, and siloxanes, and aluminum, silicon, zirconium, titanium, and the like. An inorganic compound such as an oxide or a hydrous oxide may be coated by a known method.

  Moreover, the particle | grains containing the composite of this invention can be manufactured by heating a tin oxide in presence of a nitrogen-containing compound as mentioned above. In addition, the particles obtained by coating the surface of the base particles with the composite can be produced by heating the base particles having a coating containing tin oxide in the presence of a nitrogen-containing compound. As another method, the composite particles produced in advance can be coated on the base particles by a usual method.

In order to produce particles in which the surface of the base particles is coated with the composite of the present invention, first, the base particles are coated with tin oxide. For this, a known method such as a method of depositing and coating tin oxide in a slurry of base particles can be used. Specifically, fine particles obtained by mixing a tin (IV or II) compound, an alkali, and, if necessary, a dopant with a slurry of base particles, heating to 50 ° C. or higher, and hydrolyzing the tin compound are fine particles. Therefore, it is preferable. As the tin compound, a water-soluble tin compound is preferable, and tin chloride is more preferable. As the alkali, alkali hydroxides such as sodium hydroxide, potassium hydroxide and lithium hydroxide, alkali carbonates such as sodium carbonate, ammonium compounds such as ammonium carbonate, ammonia and the like can be used. Sodium oxide is preferred. The base particles coated with tin oxide obtained by hydrolysis may be calcined in advance, and the calcining temperature can be appropriately set. Specifically, a temperature of 400 to 700 ° C. is preferable, 700 degreeC is more preferable and 600 degreeC-700 degreeC is still more preferable. Thus, tin dioxide, tin monoxide, tin oxide compound in which oxygen vacancies are generated, and the like, SnO ₂₋ indicated by _x, where, x is capable of forming a coating comprising tin oxide is a real number satisfying 0 ≦ x <2.

  Next, the base particles having a coating containing tin oxide are heated in the presence of a nitrogen-containing compound, and as the nitrogen-containing compound used at that time, a part of the tin oxide is decomposed by the heating and an oxygen-deficient tin compound is used. Any organic compound can be used as long as it is an organic compound containing nitrogen in the molecule. For example, ammonia compounds such as ammonium carbonate and ammonium hydroxide, ammonia gas, amine compounds such as alkylamines and urea compounds, amide compounds such as acid amides, and the like can be used, and the urea compounds having strong reducing power are more preferable. . As a specific method of heating, it can be carried out according to the above-described method for producing a composite. Thus, the particle | grains which coat | covered the composite containing a tin oxide and an oxygen deficient tin compound on the surface of a base particle can be manufactured.

  The composite of the present invention or particles containing the composite can be dispersed in a solvent to form a dispersion. As the solvent, water or an organic solvent such as alcohol, dimethylformamide (DMF), ketone, or a mixture thereof can be used, and industrially, an aqueous solvent mainly composed of water, dimethylformamide (DMF), ketone. Is preferably used. Examples of ketones include acetone, 2-butanone, methyl ethyl ketone, and the like. Although the density | concentration of the particle | grains containing the composite in a dispersion or a composite can be set suitably, For example, about 0.1-10 g / liter is preferable. In addition, a centrifuge may be used in a timely manner for improving dispersibility. In addition to the composite or particles containing the composite and the solvent, the dispersion includes a resin binder, a dispersant, a pH adjuster, an antifoaming agent, an emulsifier, a colorant, and an extender as long as the effects of the present invention are not impaired. Further, various additives such as an antifungal agent, a curing aid and a thickener, a filler and the like may be contained as a third component. Specifically, as the resin binder, (1) inorganic binder ((a) polymerizable silicon compound (hydrolyzable silane or hydrolysis product thereof or partial condensate thereof, water glass, colloidal silica, organopolysiloxane) Etc.), (b) metal alkoxides, etc.) and (2) organic binders (alkyd resins, acrylic resins, polyester resins, epoxy resins, fluorine resins, modified silicone resins) and the like. Dispersants include (1) surfactants ((a) anionic (carboxylates, sulfates, sulfonates, phosphates, etc.), (b) cationics (alkylamine salts, alkylamines) Quaternary ammonium salt, aromatic quaternary ammonium salt, heterocyclic quaternary ammonium salt, etc.), (c) amphoteric (betaine type, amino acid type, alkylamine oxide, nitrogen-containing heterocyclic type, etc.), (d) nonionic type ( Ether type, ether ester type, ester type, nitrogen-containing type, etc.) (2) Silicone dispersant (alkyl modified polysiloxane, polyoxyalkylene modified polysiloxane, etc.), (3) Phosphate dispersant (phosphorus) Acid sodium, sodium pyrophosphate, sodium orthophosphate, sodium metaphosphate, sodium tripolyphosphate, etc.), (4) alkanolamine (Aminomethylpropanol, aminomethylpropanediol, etc.) etc. Such a dispersion disperses the composite of the present invention or particles containing the composite and, if necessary, a third component in a solvent. As the machine, an ordinary stirrer, colloid mill, ball mill, bead mill, ultrasonic disperser, etc. can be used, and in this case, the above-mentioned third component can be added. A centrifuge or the like may be used as appropriate.

  Such a dispersion is excellent in long-term storage stability, and a composite film containing tin oxide and an oxygen-deficient tin compound can be obtained by applying the dispersion to a substrate and drying or baking. General methods such as spin coating, spray coating, roller coating, dip coating, flow coating, knife coating, electrostatic coating, bar coating, die coating, brush coating, and a method of dropping droplets can be applied to the substrate. The method can be used without limitation. If the film thickness is to be increased, overcoating may be performed. If the solvent is removed from the applied material, a composite film is formed. The film formation is preferably performed at a temperature in the range of room temperature to 800 ° C. Although more preferable temperature depends on the boiling point of the solvent, for example, in the case of an aqueous solvent, the temperature is preferably in the range of room temperature to 150 ° C, more preferably in the range of 100 to 150 ° C.

  Further, the composite of the present invention or particles containing the composite can be mixed with a resin to form a coating composition. In addition, the composite of the present invention or particles containing the composite can be mixed in a resin to obtain a resin composition such as a plastic molded body, a sheet, and a film. As such a resin, the above-mentioned resin binder, biodegradable resin, ultraviolet curable resin, thermosetting resin, and the like can be used as appropriate. The compound or the amount of particles containing the compound, and other additives A compounding quantity etc. can be set suitably. As a method for preparing the coating composition and the resin composition, the above-described method for preparing the dispersion can be used. Furthermore, a coating composition can be apply | coated on a base material and it can be set as a coating film. As the coating method, the above-described dispersion coating method can be used. Further, the composite of the present invention or particles containing the composite can be formed into a molded product. An organic compound such as a resin binder may be appropriately added to the molded product, or may be fired and sintered at an appropriate temperature.

The composite of the present invention or the particles containing the composite can be used for various functional material applications. For example, in addition to conductive fillers, it is used for visible light transmissive fillers, near infrared shielding fillers, thermal conductive fillers, semiconductors, etc., and for catalysts, photocatalysts, infrared shielding agents, ceramic / metal additives, abrasives, etc. Is also used.
Moreover, the composite film containing tin oxide and an oxygen-deficient tin compound can be used for various functional material applications. For example, in addition to a transparent material, conductive film, electrical resistor, thermal conductor, electrode, and gas sensor, a conductive oxide coat is formed by forming a composite film containing tin oxide and an oxygen-deficient tin compound on a glass substrate. Used for glass, heat ray reflective glass, low radiation glass, electrothermal glass, etc. It can also be used for photocatalytic materials, antireflection materials, gas barrier materials and the like. For use in these applications, a composite or particles containing the composite may be applied according to the form, loading state, and blending ratio conventionally used. For example, as a photocatalyst, energy higher than the band gap of tin oxide is used. By irradiating light having a wavelength, harmful substances, malodorous substances, dirt, etc. can be removed, and antifouling and antifogging effects due to the superhydrophilic effect can be utilized.

  EXAMPLES Hereinafter, although an Example demonstrates this invention, this invention is not limited to these Examples.

Example 1
10 g of tin dioxide (sample a: high-purity chemical company: purity 99.99%) and 3.0 g of urea (manufactured by Kanto Chemical Co., Ltd .: special grade) were mixed thoroughly in an agate mortar, and then put in a magnetic crucible and covered. .
The magnetic crucible was heated at 600 ° C. for 5 hours in an electric furnace under a nitrogen atmosphere. Thereafter, the mixture was cooled and drained to remove the remaining urea decomposition product, and then dried to obtain a composite of the present invention (sample A).
As a result of X-ray diffraction of Sample A, an X-ray diffraction profile of tin dioxide and an X-ray diffraction profile of an oxygen-deficient tin compound containing metal tin microcrystals were confirmed. Moreover, when X-ray diffraction measured the thing which melt | dissolved the surface vicinity of the sample A partially with the electron microscope by X-ray diffraction, from the X-ray-diffraction profile of the oxygen deficient tin compound containing a metal tin microcrystal had disappeared. It was found that the oxygen-deficient tin compound containing metal tin microcrystals was present near the surface of the tin dioxide particles.

Example 2
A composite (sample B) of the present invention was obtained in the same manner as in Example 1, except that the amount of urea was changed to 2.0 g.
As a result of the X-ray diffraction of the sample B, the X-ray diffraction profile of tin dioxide and the X-ray diffraction profile of the oxygen-deficient tin compound containing metal tin microcrystals were confirmed. Similar to 1, it was found that the oxygen-deficient tin compound containing metal tin microcrystals was present near the surface of the tin dioxide particles.

Example 3
A composite (sample C) of the present invention was obtained in the same manner as in Example 1, except that the amount of urea was changed to 1.0 g.
As a result of X-ray diffraction of sample C, an X-ray diffraction profile of tin dioxide and an X-ray diffraction profile of an oxygen-deficient tin compound containing tin metal microcrystals and Sn ₂ O ₃ were confirmed. As a result of the test, as in Example 1, it was found that the oxygen-deficient tin compound containing metal tin microcrystals and Sn ₂ O ₃ was present in the vicinity of the surface of the tin dioxide particles.

Example 4
A composite of the present invention (sample D) was obtained in the same manner as in Example 1, except that the amount of urea was changed to 0.5 g.
As a result of X-ray diffraction of sample D, an X-ray diffraction profile of tin dioxide and an X-ray diffraction profile of an oxygen-deficient tin compound containing metal tin microcrystals were confirmed. Similar to 1, it was found that the oxygen-deficient tin compound containing metal tin microcrystals was present near the surface of the tin dioxide particles.

Example 5
A composite (sample E) of the present invention was obtained in the same manner as in Example 1, except that 3.0 g of melamine (manufactured by Wako Pure Chemical Industries, Ltd .: purity 98%) was used instead of urea.
As a result of X-ray diffraction of sample E, an X-ray diffraction profile of tin dioxide and an X-ray diffraction profile of an oxygen-deficient tin compound containing metal tin microcrystals were confirmed. Similar to 1, it was found that the oxygen-deficient tin compound containing metal tin microcrystals was present near the surface of the tin dioxide particles.

Example 6
In Example 5, the composite (sample F) of the present invention was obtained in the same manner except that the amount of melamine was changed to 2.0 g.
As a result of X-ray diffraction of sample F, an X-ray diffraction profile of tin dioxide and an X-ray diffraction profile of an oxygen-deficient tin compound containing metal tin microcrystals were confirmed. Similar to 1, it was found that the oxygen-deficient tin compound containing metal tin microcrystals was present near the surface of the tin dioxide particles.

Example 7
In Example 5, the composite (sample G) of the present invention was obtained in the same manner except that the amount of melamine was changed to 1.0 g.
As a result of the X-ray diffraction of the sample G, the X-ray diffraction profile of tin dioxide and the X-ray diffraction profile of the oxygen-deficient tin compound containing metal tin microcrystals were confirmed. Similar to 1, it was found that the oxygen-deficient tin compound containing metal tin microcrystals was present near the surface of the tin dioxide particles.

Example 8
In Example 5, the composite (sample H) of the present invention was obtained in the same manner except that the amount of melamine was changed to 0.5 g.
As a result of X-ray diffraction of sample H, an X-ray diffraction profile of tin dioxide and an X-ray diffraction profile of an oxygen-deficient tin compound containing metal tin microcrystals were confirmed. Similar to 1, it was found that the oxygen-deficient tin compound containing metal tin microcrystals was present near the surface of the tin dioxide particles.

Example 9
A composite (sample I) of the present invention was obtained in the same manner as in Example 1, except that tin monoxide was used instead of tin dioxide.
As a result of the X-ray diffraction of Sample I, the X-ray diffraction profile of tin monoxide and the X-ray diffraction profile of the oxygen-deficient tin compound containing metal tin microcrystals were confirmed. As in Example 1, it was found that the oxygen-deficient tin compound containing metal tin microcrystals was present near the surface of the tin monoxide particles.

Comparative Example 1
The above tin oxide powder (sample a) was used as a comparative sample.

Evaluation 1: Powder Resistance For each sample of Examples 1 to 8 and Comparative Example 1, 1.0 g was molded into a cylindrical shape (18 mmφ) at a pressure of 4 MPa, and the DC resistance was changed to a digital multimeter (Model 3457A type: Hewlett). And the powder resistance value was calculated by the following equation. The smaller the powder resistance value, the better the conductivity.
Powder resistance value = Measured value × Cylinder cross-sectional area / Cylinder thickness

Evaluation 2: Evaluation of powder color Each sample of Examples 1 to 8 and Comparative Example 1 was filled in a dedicated glass cell having an outer diameter of 35 mm, and the L value according to the Hunter color system of the molded product was measured with a whiteness meter (NW -1 type: manufactured by Nippon Denshoku Industries Co., Ltd.). It means that whiteness is excellent, so that L value is high.

Table 1 shows the measurement results of powder resistance and powder color. The powder resistance value of the sample of the present invention is lower than that of the comparative example. When urea is used, 1.0 × 10 ² Ωcm or less, and when melamine is used, the powder resistance is further reduced by an order of magnitude. It was found to be × 10 ¹ Ωcm or less and excellent in conductivity. On the other hand, it was found that the L value was lowered in Examples because of the production of oxygen-deficient tin compounds containing metal tin microcrystals and the like.

Evaluation 3: Nitrogen ratio on the surface (analysis of the vicinity of the particle surface by XPS measurement method)
About what washed the sample obtained in Example 1, the amount of nitrogen near the surface was measured by XPS under the following conditions, and was not detected.
Apparatus: Quantera SXM (manufactured by PHI)
Excitation X-ray: monochromatic Al Ka 1, 2 line (1486.6 eV)
X-ray diameter: 100 μm ²
Photoelectron escape angle (inclination of detector relative to sample surface): 45 °
Sample fixing: Fixed to an indium foil by pressure bonding.

(Whole particle analysis using oxygen / nitrogen analyzer)
The sample obtained in Example 1 was washed and analyzed by the He gas melting method using impulse furnace heating under the following conditions. As a result, an extremely small amount of 0.01% was detected.
Apparatus: TC-600 (manufactured by Leco)
Sample: 3 mg was placed in a graphite crucible and introduced into the apparatus.
Atmosphere: He gas 450 ml / min.

The composite of the present invention or a particle containing the composite contains an oxygen-deficient tin compound such as tin oxide and metal tin microcrystals, and in addition to the conductive filler, a visible light transmitting filler, a near-infrared shielding filler, a heat conduction It is used for fillers, semiconductors, and the like, and is also used for catalysts, photocatalysts, infrared shielding agents, ceramics / metal additives, abrasives, molded articles, and the like.
In addition to transparent materials, conductive films, electrical resistors, electrodes, and gas sensors, composite films formed from composites or particles containing composites are formed by forming a composite film on a glass substrate and conducting oxidation. Used for product coated glass, heat ray reflective glass, low radiation glass, electrothermal glass and the like. It can also be used for various applications such as photocatalytic materials, antireflection materials, and gas barrier materials.

Claims (10)

Tin oxide represented by SnO _2-x (wherein x is a real number satisfying 0 ≦ x <2) and oxygen-deficient tin compound represented by SnO _2-xy (wherein x is as defined above) And y is a real number satisfying 0 <y ≦ 2-x.).   The composite according to claim 1, comprising an oxygen-deficient tin compound on the surface and / or inside of the tin oxide particles.   A particle comprising the composite according to claim 1. The presence of a nitrogen-containing compound, (where, x is a real number satisfying 0 ≦ x <2.) Tin oxide represented by _{SnO 2-x} heating the tin oxide represented by _{SnO 2-x} (wherein , X is a real number satisfying 0 ≦ x <2) and an oxygen-deficient tin compound represented by SnO _2-xy (wherein x is as described above and y is 0 <y ≦ 2-x). A real number satisfying the above)).   The method for producing a composite according to claim 4, wherein the nitrogen-containing compound is a urea compound.   A dispersion containing the composite according to claim 1 or 2 or the particles according to claim 3.   A coating composition containing the composite according to claim 1 or 2 or the particles according to claim 3.   A resin composition comprising the composite according to claim 1 or 2 or the particles according to claim 3. A molded article containing the composite according to claim 1 or 2 or the particles according to claim 3.   A coating film formed by applying the dispersion according to claim 6 or the coating composition according to claim 7 on a substrate.