JP2005133205A - Particle for functional material, and manufacturing method of functional material and particle for functional material - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a particle for a functional material, which composes the functional material and can improve easily functions imparted to the functional material, and its manufacturing method. <P>SOLUTION: The particle for the functional material is used for forming the functional material and contains metal particle having an outer surface, in which a first surface part containing a metal carbide and a second surface part extending outward from the first surface part are formed on at least a part of the outer surface of the metal particle. The manufacturing method of the particle for the functional material comprises a step of placing the metal particle inside a space containing a hydrocarbon-containing substance and a step of heating the metal particle to a temperature equal to or lower than the melting point of the metal. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to functional material particles, a functional material, and a method for producing functional material particles, and in particular, a conductive paint, a conductive resin composition, a filter material, a catalyst carrier, a methane generating material, and a portable energy generating material. The present invention relates to functional material particles used for forming functional materials such as additives for high temperature resistant materials, electrode materials, and sensor materials, and a method for producing the same.

  2. Description of the Related Art In recent years, devices and devices that use electricity or electronics are required to have functions such as shielding electromagnetic waves caused by these devices, etc., anti-static properties, and preventing external static electricity generation. It has become like this. In order to meet these requirements, a conductive material such as a conductive paint or a conductive resin composition is attached to the outer surface of a component such as an electric / electronic device or apparatus. These conductive materials are required to have high conductivity sufficient to ensure a predetermined electromagnetic shielding effect.

  For example, in order to constitute a conductive paint as one of the conductive materials, a filler made of silver or nickel or copper is dispersed in a binder made of rubber or resin, and a filler made of a metal material of silver, nickel or copper is scattered between the fillers. Japanese Patent Application Laid-Open No. 10-316901 (Patent Document 1) discloses a stainless steel metal fiber that can come into contact with the metal. Also, Japanese Patent Laid-Open No. 10-27986 (Patent Document 2) discloses a composition in which carbon black and carbon fiber are blended in a resin to constitute a radio wave absorber as one of the conductive materials. ing.

  However, when a metal material, i.e., metal particles, is used as the filler or fiber material to form the conductive material, the average particle diameter of the metal particles is relatively large, so that the contact area between adjacent particles is small. For this reason, a conductive passage having a large cross-sectional area cannot be formed in the insulating binder. Thereby, although the electrical conductivity of metal particle itself is excellent, the electroconductivity of the electroconductive material comprised by mixing with a binder cannot be improved.

  In addition, when silver is used as the filler material, it is difficult to industrially use silver particles for constituting the conductive material because silver ingot is relatively expensive. In the case of using copper, since the copper powder is very easily oxidized, it is used for various surface treatments, for example, conductive paints as proposed in JP-A-3-68702 (Patent Document 3). For this purpose, it is necessary to treat the copper powder with a metal alkoxide solution and then coat it with a metal acylate compound. When nickel or stainless steel is used, there is no problem of a decrease in conductivity due to an oxide film, but since the specific gravity is large, there is a problem that particles are likely to settle down when mixed with a binder. Furthermore, it is conceivable to use aluminum, but the oxide film covering the surface significantly reduces the conductivity of the aluminum particles. Therefore, even if the aluminum particles are used as they are to form the conductive material, the conductivity of the conductive material is reduced. It is difficult to improve.

  On the other hand, since carbon black has an average particle size smaller than that of metal particles, the contact area between adjacent carbon blacks can be increased by blending in an insulating resin to form a conductive material, It can be expected that a conductive passage having a large cross-sectional area is formed. However, since carbon black has a small average particle size, it easily aggregates. Therefore, depending on the method of dispersing in the binder or resin or the conditions for the dispersion, etc. There is a problem that it is difficult to obtain conductivity sufficient to satisfy the above. In addition, since the conductivity of the carbon black particles themselves is inferior to that of metal particles, there is a problem that the use of the particles for conductive materials is limited depending on the degree of function realized by the low conductivity.

In recent years, it has been required to increase the surface area as one characteristic for improving the performance of functional materials such as catalysts and electrodes. For example, the platinum catalyst for fuel cells has a problem that the specific surface area decreases during use because platinum particles aggregate due to thermal diffusion, and the catalyst performance deteriorates. For this reason, there is a demand for a catalyst carrier having a shape in which platinum particles cannot easily move due to thermal diffusion.
JP-A-10-316901 JP-A-10-27986 Japanese Patent Laid-Open No. 3-68702

  Accordingly, one object of the present invention is to provide functional material particles and a method for producing the same that can easily enhance the function imparted when the functional material is constructed.

  Another object of the present invention is to provide a functional material provided with particles that can easily enhance the function to be imparted.

  As a result of intensive studies to solve the problems of the background art, the present inventor has found that functional material particles capable of achieving the above object can be obtained by performing specific treatment on metal particles. It was. The present invention has been made based on such knowledge of the inventors.

  A functional material particle according to one aspect of the present invention is a functional material particle used to form a functional material, the metal particle having an outer surface, and at least a part of the outer surface of the metal particle. A first surface portion including a metal carbide and a second surface portion formed to extend outward from the first surface portion.

  In the particles for functional materials of the present invention, the second surface portion acts to increase the specific surface area on the outer surface of the particles. This increases the surface area of the outer surface of the particles, and increases the contact area between adjacent particles when constituting the functional material. Therefore, when the functional material is constituted by ensuring the particles have a predetermined function, the function can be easily enhanced.

  In the functional material particles of the present invention, the metal is preferably aluminum or an aluminum alloy. Usually, aluminum or aluminum alloy particles are difficult to obtain high conductivity because of the oxide film covering the surface. However, even if aluminum or an aluminum alloy is used as the metal constituting the base material particles in the functional material particles of the present invention, the entire outer surface of the metal particles is not covered with an oxide film, so that the conductivity is remarkably increased. It becomes possible to improve.

  In the functional material particle of the present invention, the second surface portion preferably contains a metal and carbon. In this case, the second surface portion can be firmly bonded to the metal particles themselves.

  In the functional material particle of the present invention, the second surface portion preferably contains a metal carbide. In this case, not only the first and second surface portions are formed of metal carbide, but also all of the base material particles may be formed of metal carbide.

  The functional material particles of the present invention are preferably conductive material particles. In this case, the metal particles themselves act to increase conductivity, and the first surface portion containing the metal carbide and the second surface portion do not impair the conductivity, and the second surface portion It acts to increase the specific surface area on the outer surface of the particles. Thereby, when the particle | grains for conductive materials comprise a conductive material, the contact area between adjacent particle | grains increases. Therefore, when the conductive material is formed by ensuring the particles have a predetermined conductivity, a conductive passage having a large cross-sectional area can be easily formed between the particles. Furthermore, since the contact area with the binder also increases, even particles having a large specific gravity are less likely to settle down. As a result, the conductivity of the conductive material can be easily increased.

  The functional material particles of the present invention are preferably catalyst carrier particles. In this case, the metal particles themselves are excellent in heat dissipation, and the first surface portion containing the metal carbide and the second surface portion do not impair the heat dissipation, and the second surface portion is outside the particles. It acts to increase the specific surface area on the surface. As a result, more catalyst can be supported when the catalyst support particles constitute the catalyst support.

  The particles for functional material of the present invention are preferably particles for additives of high temperature resistant materials, for example, particles for additives for enhancing strength of high temperature heat resistant bricks. In this case, the second surface portion that acts to increase the specific surface area acts to increase the contact area with the brick material. Thereby, when the particle | grains for additives comprise the brick strengthening additive, it can react with a brick material more rapidly and uniformly.

  The functional material particles of the present invention are preferably methane generating material particles. In this case, the second surface portion that acts to increase the specific surface area acts to increase the contact area with water. Thereby, when the particle | grains for methane generating material are immersed in water, it reacts with water more rapidly and uniformly, and methane gas manufacturing time can be shortened. Therefore, productivity of a portable energy source can be improved by using the particles for methane generating material as the functional material particles of the present invention.

  The functional material particles of the present invention are preferably filter material particles. In this case, a part of or all of the particles of the substrate are formed from a metal carbide, and the second surface portion that acts to increase the specific surface area is brought into contact with the second surface portion of the adjacent particle, thereby causing the specific surface area. A large filter material can be formed. Thereby, the metal carbide filter of the high specific surface area applied to a high temperature environment can be manufactured.

  The functional material according to another aspect of the present invention contains functional material particles having any of the above-described characteristics.

  According to still another aspect of the present invention, there is provided a method for producing functional material particles used for forming a functional material, the step of arranging metal particles in a space containing a hydrocarbon-containing substance, Heating the particles below the melting point of the metal.

  In the manufacturing method of the present invention, the first surface portion containing the metal carbide is formed on the outer surface of the metal particle by heating the metal particle disposed in the space containing the hydrocarbon-containing substance to a temperature equal to or lower than the melting point of the metal. A second surface portion that includes carbon and acts to increase the specific surface area on the outer surface of the particle can be easily formed to extend outward from the first surface portion.

  In the production method of the present invention, the step of arranging the metal particles comprises mixing the metal particles and the carbon-containing material, and then arranging the mixture of the metal particles and the carbon-containing material in the space containing the hydrocarbon-containing material. Is preferred. In this case, a thick second surface portion can be formed.

  As described above, according to the present invention, when a functional material is configured by ensuring the particles have a predetermined function, functional material particles capable of easily enhancing the function can be obtained. In particular, since the specific surface area on the outer surface of the particles can be increased in this invention, functional materials such as conductive materials, filter materials, catalyst materials, methane generating materials, portable energy generating materials, additives for high temperature resistant materials, etc. By using the particles for a functional material of the present invention to constitute a predetermined function, a predetermined function can be easily enhanced.

  As one embodiment of the present invention, the metal forming the particles as the substrate on which the first surface portion containing metal carbide and the second surface portion containing carbon are formed is not particularly limited, Silver (Ag), aluminum (Al), copper (Cu), nickel (Ni), titanium (Ti), stainless steel, or the like can be used. Aluminum is particularly preferably used because it is inexpensive, has a small specific gravity, and can be easily produced in the form of particles. The metal forming the particles used in the present invention is composed of silver, aluminum, copper, nickel, titanium, lead (Pb), silicon (Si), iron (Fe), manganese (Mn), magnesium (Mg). An alloy to which at least one alloy element selected from the group consisting of chromium (Cr), zinc (Zn), vanadium (V), gallium (Ga) and boron (B) is added within the necessary range, or Also included is a metal containing a limited content of these inevitable impurity elements.

  The shape of the metal particle is not particularly limited, and an indefinite shape, a spherical shape, or a scale-like particle shape can be used. The average particle diameter of the metal particles is not particularly limited as long as it is smaller than the thickness of the functional material constituted by using the metal particles, but generally it is preferably 0.01 μm or more and 10,000 μm or less. When the average particle size is less than 0.01 μm, it is difficult to produce industrially stably, and the price is remarkably increased. On the other hand, when the average particle diameter exceeds 10,000 μm, the specific surface area is greatly reduced, and therefore the function of the functional material particles is lowered, which is not preferable.

  As said metal particle, what is manufactured by a well-known method can be used. For example, as the stainless steel particles, there can be used, for example, a material obtained by physically pulverizing a rolled stainless steel material by intergranular corrosion or a water atomized stainless steel melt. As the aluminum particles, those obtained by gas atomizing a molten aluminum may be used. Furthermore, the obtained metal particles that are physically flattened by a stamp mill or a ball mill are also preferably used. The metal particles used in the present invention are particularly preferably aluminum particles flattened by a ball mill.

  In one embodiment of the method for producing functional material particles of the present invention, the type of the hydrocarbon-containing substance used is not particularly limited. The types of hydrocarbon-containing substances include, for example, paraffinic hydrocarbons such as methane, ethane, propane, n-butane, isobutane and pentane, olefinic hydrocarbons such as ethylene, propylene, butene and butadiene, and acetylenes such as acetylene. Examples thereof include hydrocarbons and derivatives of these hydrocarbons. Among these hydrocarbons, paraffinic hydrocarbons such as methane, ethane, and propane are preferable because they become gaseous in the process of heating the metal particles. More preferred is any one of methane, ethane and propane. The most preferred hydrocarbon is methane.

  The hydrocarbon-containing substance may be used in any state such as liquid or gas in the production method of the present invention. The hydrocarbon-containing material may be present in the space where the metal particles are present, and may be introduced into the space where the metal particles are disposed by any method. For example, when the hydrocarbon-containing substance is gaseous (methane, ethane, propane, etc.), the hydrocarbon-containing substance may be filled alone or together with an inert gas in a sealed space where the heat treatment of the metal particles is performed. . Further, when the hydrocarbon-containing substance is a liquid, the hydrocarbon-containing substance may be filled alone or together with an inert gas so as to be vaporized in the sealed space.

  In the step of heating the metal particles, the pressure of the heating atmosphere is not particularly limited, and may be normal pressure, reduced pressure or increased pressure. Further, the pressure adjustment may be performed at any time during the temperature rise to a certain heating temperature or during the temperature lowering from the certain heating temperature while the pressure is maintained at a certain heating temperature.

  The weight ratio of the hydrocarbon-containing substance introduced into the space in which the metal particles are arranged is not particularly limited, but is usually in the range of 0.01 to 50 parts by weight in terms of carbon with respect to 100 parts by weight of the metal particles. The content is preferably in the range of 0.1 to 30 parts by weight.

  In the step of heating the metal particles, the heating temperature may be appropriately set according to the composition of the metal particles that are the object to be heated, but is preferably within the range below the melting point of the metal, and the metal particles are aluminum or an aluminum alloy. In some cases, it is more preferably performed at 450 ° C. or higher. However, in the production method of the present invention, heating the aluminum particles at a temperature lower than 450 ° C. is not excluded, and the aluminum particles may be heated at a temperature exceeding at least 300 ° C.

  Although the heating time depends on the heating temperature or the like, it is generally in the range of 30 seconds to 100 hours.

  When the heating temperature is 400 ° C. or higher, the oxygen concentration in the heating atmosphere is preferably 1.0% by volume or lower. When the heating temperature is 400 ° C. or higher and the oxygen concentration in the heating atmosphere exceeds 1.0% by volume, the thermal oxide film on the surface of the aluminum particles may be enlarged, and the interface electrical resistance on the surface of the metal particles may be increased.

  Moreover, you may granulate a metal particle before heat processing. The granulation method is not particularly limited, and a known technique such as spray drying or rolling granulation can be used.

  In the manufacturing method of the present invention, when forming the thick second surface portion, after mixing the metal particles and the carbon-containing substance, placing the mixture in the space containing the hydrocarbon-containing substance, the mixture is made below the melting point of the metal Heat to. In this case, the carbon-containing substance mixed with the metal particles may be any of activated carbon fiber, activated carbon cloth, activated carbon felt, activated carbon powder, black ink, carbon black or graphite. In the mixing method, metal particles may be added to the above-mentioned carbon-containing material prepared in a slurry or liquid form using a binder or a solvent. After mixing the metal particles and the carbon-containing substance, it may be dried at a temperature in the range of 20 ° C. or more and 300 ° C. or less.

The second surface portion containing carbon in the present invention extends outwardly from the first surface portion containing metal carbide, and preferably exists in a porous, filamentous or fibrous form and has a high specific surface area. Therefore, it acts to increase the contact area with adjacent particles. As a result, in the functional material constituted by blending the particles for functional material of the present invention, the function can be easily enhanced when the particles have a predetermined function. The specific surface area of the functional material particles varies depending on the specific gravity, average particle diameter, shape and the like of the particles, but is preferably 2 m ² / g or more, more preferably 5 m ² / g or more. The upper limit value of the specific surface area is not particularly limited, but may be about 10,000 m ² / g.

In particular, when the metal particles of the present invention are aluminum or an aluminum alloy, the first and second surface portions are formed on the surface of the metal particles instead of the oxide film, so that the conductivity is remarkably improved. The thickness of the oxide film can be relatively evaluated by the ratio of the oxygen amount (%) to the specific surface area (m ² / g).

  In particular, when the conductive material is configured by blending the particles of the present invention, the metal particles themselves act to increase the conductivity, and the first surface portion containing the metal carbide and the second surface containing carbon. The surface portion does not impair the conductivity, and the second surface portion acts to increase the specific surface area on the outer surface of the particle. This increases the contact area between adjacent particles when forming the conductive material. Therefore, when the conductive material is formed by ensuring the particles have a predetermined conductivity, a conductive passage having a large cross-sectional area can be easily formed between the particles. As a result, the conductivity of the conductive material can be easily increased.

  According to the production method of the present invention, it is possible to provide new functional material particles on an industrial scale. Moreover, the particles for functional materials obtained by the present invention can exhibit characteristics superior to conventional materials as a whole.

  In the present invention, since the second surface portion acts to increase the specific surface area on the outer surface of the particles, there are various application fields as particles having a large specific surface area. For example, as particles for conductive materials In addition to the use of, for filter material particles, particles for catalyst materials, particles for methane generating materials, particles for portable energy generating materials, and additives for high temperature resistant materials that are used in such a way that the particles have a predetermined function. It can also be used as particles, particles for electrode materials, particles for sensor materials, and the like.

  For example, when the functional material particles of the present invention are used as catalyst carrier particles, the second surface portion increases the specific surface area on the outer surface of the particles and acts to support the catalyst. Furthermore, since the metal particles themselves act to enhance heat dissipation, the functional material particles of the present invention can be suitably used at high temperatures.

  In addition, for example, when the filter material is configured using the functional material particles of the present invention, the second surface portion containing carbon extends outward from the first surface portion containing metal carbide, and is in the form of a filament. Or since it exists in a fibrous form and has a high specific surface area, adjacent particles are strongly bonded by the action of increasing the contact area with the adjacent particles, and a filter material having a very large specific surface area can be easily formed. In particular, when not only the first and second surface portions of the functional particles are formed of metal carbide, but also part or all of the base material particles are formed of metal carbide, an extremely high temperature is obtained. The filter material that can be used in the above can be easily formed.

  Further, for example, the functional material particles of the present invention have a property of reacting with water to generate methane. Utilizing this characteristic, in particular, the first and second surface portions are not only formed from a carbide of metal such as aluminum, but also part or all of the particles of the substrate are formed from a carbide of metal such as aluminum. When formed, the second surface portion acts to increase the specific surface area of the outer surface of the particle, so that the contact area with water is large and the methane production reaction is accelerated. In this case, a portable energy generating material can be constituted using the functional material particles of the present invention.

  For example, an electrode material can be configured using the functional material particles of the present invention. In this case, the electrodes can be applied to lithium ion batteries, fuel cells, electric double layer capacitors, electrolytic capacitors, and the like.

  For example, a sensor material can be configured using the functional material particles of the present invention. In this case, the sensor can be applied to a current sensor, a contact sensor, a tactile sensor, a high temperature sensor, a pressure sensor, a radiation sensor, an infrared sensor, a piezoelectric sensor, and the like.

  Further, the functional material particles of the present invention may be crushed to obtain new functional material particles. The functional material particles may be crushed by a known method, and examples thereof include ball mill, rod mill, vibration mill, jaw crusher, roll crusher, sand mill and the like. The functional material particles of the present invention may be crushed and a part thereof may be separated to obtain new functional material particles.

  Moreover, you may perform the surface treatment which provides water resistance and acid resistance with respect to the particle | grains for functional materials of this invention according to the use. The surface treatment method may be carried out according to a known method, and examples thereof include a treatment for chemically coating the surface with an organic substance such as a resin or an inorganic substance such as silica, and a high-temperature oxidation treatment. As the surface treatment method, a physical method of vacuum deposition of carbon or the like is also preferably used.

  The method for forming a functional material may include a step of placing preformed metal particles in a space containing a hydrocarbon-containing substance, and a step of heating the metal particles to a temperature equal to or lower than the melting point of the metal.

  In addition, as a method for forming the functional material, the functional material particles may be converted into ink and applied. Inking may be performed by a known method. For example, the functional material particles may be mixed with a resin and a crosslinking agent and then dissolved or dispersed in a solvent. In this case, a known method can be adopted as a coating method, and it can be applied by brush coating, spray coating, roll coater, bar coater, doctor blade or the like. In addition to these methods, a method of simply immersing a functional material support in ink containing functional material particles may be used.

  When molding the functional material, known additives may be added together with the functional material particles. For example, anti-settling agent, antioxidant, corrosion inhibitor, antifoaming agent, thickener, plasticizer, dispersant, curing catalyst, UV absorber, surface conditioner, sagging agent, leveling agent, tack fire, cup A ring agent or the like may be added as necessary.

  According to the following Examples 1-4, the particle | grains for electroconductive materials were produced as one application example of the particle | grains for functional materials, and the electroconductive coating material was produced as an electroconductive material using the particle | grains. For comparison with Examples 1 to 4, in Conventional Example 1, a conductive paint was produced using aluminum particles as particles for conductive material as they were.

(Example 1)
By heating flaky aluminum particles (trade name “P0100” manufactured by Toyo Aluminum Co., Ltd.) having an average particle diameter of 18 μm and a specific surface area of 5.4 m ² / g in methane gas at a temperature of 630 ° C. for 10 hours, Particles for conductive material were prepared. Using this conductive material particle, 200 parts by weight of a slurry prepared by adding thinner so that the solid content of the conductive material particle is 45%, acrylic lacquer (trade name “Acridic A-165”; solid The conductive coating material was prepared by uniformly dispersing 50% by weight) at a ratio of 50 parts by weight using a disper.

(Example 2)
By heating flaky aluminum particles (trade name “P1415” manufactured by Toyo Aluminum Co., Ltd.) having an average particle diameter of 61 μm and a specific surface area of 1.9 m ² / g in methane gas at a temperature of 630 ° C. for 10 hours, Particles for conductive material were prepared. A conductive paint was produced in the same manner as in Example 1 using the particles for conductive material.

(Example 3)
10 parts by weight of scaly aluminum particles (trade name “P0100” manufactured by Toyo Aluminum Co., Ltd.) having an average particle diameter of 18 μm and a specific surface area of 5.4 m ² / g, and 10 carbon blacks having an average particle diameter of 0.0018 μm. Particles for conductive material were prepared by mixing at a weight part ratio and heating the mixture in methane gas at a temperature of 630 ° C. for 10 hours. A conductive paint was produced in the same manner as in Example 1 using the particles for conductive material.

Example 4
Conductive material particles are produced by heating spherical aluminum particles (manufactured by Toyo Aluminum Co., Ltd.) having an average particle diameter of 78 μm and a specific surface area of 0.3 m ² / g in methane gas at a temperature of 630 ° C. for 10 hours. did. A conductive paint was produced in the same manner as in Example 1 using the particles for conductive material.

(Conventional example 1)
Flaky aluminum particles (trade name “P0100” manufactured by Toyo Aluminum Co., Ltd.) having an average particle diameter of 18 μm and a specific surface area of 5.4 m ² / g were used as conductive material particles. A conductive paint was produced in the same manner as in Example 1 using the particles for conductive material.

  The characteristics of the particles for conductive material and the characteristics of the conductive material (conductive paint) obtained in Examples 1 to 4 and Conventional Example 1 were measured as follows.

[Elemental analysis]
With a powder X-ray diffractometer (RINT2000, RINT2000), the presence or absence of carbides on the surface of the conductive material particles was confirmed. Further, the amount of oxygen in the particles for the conductive material was measured by dissolution in an inert gas-infrared absorption method.

[Average particle size]
The average particle diameter of the particles for conductive material was measured using a laser diffraction particle size distribution analyzer (Honeywell, Microtrac HRA). Note that water was used as the dispersion medium.

[Specific surface area]
Using a specific surface area measuring device (trade name “Micrometritics Flow Sorb II 2003” manufactured by Shimadzu Corporation), the specific surface area of the particles for conductive material was measured by the BET single point method.

[Surface resistivity]
The surface resistivity of the coating film formed by applying conductive paint on a glass plate using a doctor blade 9 mil and drying for 20 minutes at a temperature of 50 ° C. is a high resistivity meter (trade name “Hiresta-UP” (Mitsubishi Chemical Corporation).

  These measurement results are shown in Table 1.

As can be seen from these measurement results, in the particles for conductive materials of Examples 1 to 4, a large specific surface area could be obtained although the average particle diameter was relatively large. In addition, in the conductive materials of Examples 1 to 4, it was possible to obtain a surface resistivity lower than that of the conductive material configured using the aluminum particles of Conventional Example 1 as they are.

  Further, scanning electron micrographs of the conductive material particles used in Example 2 and the conductive material particles used in Example 4 are shown in FIGS. 1 and 2, respectively. As shown in FIG. 1, the outer surface of a part of three flaky particles is observed, and the second surface portion extends outward from the outer surface of the particle in the form of a fiber, a filament, or a flake. You can see that As shown in FIG. 2, the outer surface of one spherical particle is observed, and it can be seen that the second surface portion extends outward from the outer surface in the form of a fiber or filament. The second surface portion in the form of a fiber, filament, or flake that looks like this serves to increase the specific surface area of the particles and increase the contact area between adjacent particles in the conductive material.

(Example 5)
Particles for functional material were obtained by heating granular aluminum particles (manufactured by Toyo Aluminum Co., Ltd.) having an average particle diameter of 1 μm in methane gas at a temperature of 630 ° C. for 10 hours. Thereafter, carbon was deposited in a thickness of 20 nm in a vacuum. The acid resistance was evaluated to be 98 mg.

(Conventional example 2)
Carbon was vapor-deposited with a thickness of 20 nm in vacuum on granular aluminum particles having an average particle diameter of 1 μm (manufactured by Toyo Aluminum Co., Ltd.). When acid resistance was evaluated, all were dissolved.

  The acid resistance of the functional material particles obtained in Example 5 and Conventional Example 2 was measured as follows.

[Acid resistance]
100 mg of bromomethyl alcohol was charged with 100 mg of functional material particles, and the weight after 24 hours was measured to evaluate acid resistance.

(Example 6)
5 parts by weight of granular aluminum particles (manufactured by Toyo Aluminum Co., Ltd.) having an average particle diameter of 1 μm and 1 part by weight of an acrylic resin were mixed to prepare a slurry. Then, the slurry was apply | coated on the sheet | seat of the polyethylene terephthalate with the doctor blade method, it dried and peeled, and the sheet | seat of thickness 0.5mm was produced. The sheet was dried at 300 ° C. for 40 hours and then heated in methane gas at 630 ° C. for 48 hours to obtain a filter. It was 50 m < ² > / g when the specific surface area of the filter was measured.

(Conventional example 3)
A slurry was prepared by mixing 5 parts by weight of alumina particles having an average particle diameter of 1 μm and 1 part by weight of acrylic resin. Then, the slurry was apply | coated on the sheet | seat of the polyethylene terephthalate with the doctor blade method, it dried and peeled, and the sheet | seat of thickness 0.2mm was produced. The sheet was dried at 200 ° C. for 1 hour and then sintered in argon gas at 1700 ° C. to obtain a filter. It was 1 m < ² > / g when the specific surface area of the filter was measured.

(Example 7)
A slurry was prepared by mixing 5 parts by weight of scaly aluminum particles (Toyo Aluminum Co., Ltd.) having an average particle diameter of 2 μm and a specific surface area of 15 m ² / g, and 2 parts by weight of an acrylic resin. Then, the slurry was apply | coated on the sheet | seat of the polyethylene terephthalate with the doctor blade method, it dried and peeled, and the sheet | seat of thickness 0.2mm was produced. The sheet was dried at 300 ° C. for 40 hours and then heated at 630 ° C. for 40 hours in a methane gas atmosphere to obtain a catalyst carrier. The specific surface area of the catalyst support was measured and found to be 100 m ² / g.

(Conventional example 4)
A slurry was prepared by mixing 5 parts by weight of alumina particles having an average particle size of 0.5 μm and 1 part by weight of acrylic resin. Then, the slurry was apply | coated on the sheet | seat of the polyethylene terephthalate with the doctor blade method, it dried and peeled, and the sheet | seat of thickness 0.2mm was produced. The sheet was dried at 200 ° C. for 1 hour and then sintered in argon gas at 1700 ° C. to obtain a catalyst carrier. The specific surface area of the catalyst support was measured and found to be 2.8 m ² / g.

  The specific surface areas of the filters or catalyst carriers obtained in Examples 6 and 7 and Conventional Examples 3 and 4 were measured as follows.

[Specific surface area]
The specific surface area was measured by the BET single point method using a specific surface area measuring device (trade name “Micrometritics Flow Sorb II 2003” manufactured by Shimadzu Corporation).

(Example 8)
Particles for functional material obtained by heating granular aluminum particles (manufactured by Toyo Aluminum Co., Ltd.) having an average particle size of 10 μm in methane gas at a temperature of 630 ° C. for 20 hours are crushed by a bead mill, and the average particle size is 0. Particles for strength enhancing additive of 1 μm were obtained. One part by weight of particles for strength-enhancing additives was added to 50 parts by weight of heat-resistant brick material consisting of 90% by weight of alumina and 10% by weight of silicon carbide, and fired at 1300 ° C. in argon gas to obtain a high-temperature resistant material. The compressive strength was measured and found to be 253 MPa.

(Conventional example 5)
1 part by weight of commercially available aluminum carbide having an average particle diameter of 20 μm as a particle for strength enhancing additive was added to 50 parts by weight of the heat-resistant brick material used in Example 8, and fired at 1300 ° C. in an argon gas. Got. The compressive strength was measured and found to be 189 MPa.

  The compressive strength of the high temperature resistant material obtained in Example 8 and Conventional Example 5 was measured as follows.

[Compressive strength]
A high temperature resistant material fired to 60 cm × 250 cm × 5 cm was subjected to a compression test using an Amsler type compression tester, and the compression strength was evaluated.

  It should be considered that the embodiments and examples disclosed above are illustrative and non-restrictive in every respect. The scope of the present invention is shown not by the above embodiments but by the scope of claims, and includes all modifications and variations within the meaning and scope equivalent to the scope of claims.

  By using the particles for functional material according to the present invention, conductive paint, conductive resin composition, filter material, catalyst carrier, methane generating material, portable energy generating material, additive for high temperature resistant material, electrode material, A functional material such as a sensor material can be formed.

The scanning electron micrograph of the particle | grains for electroconductive materials used in Example 2 is shown. The scanning electron micrograph of the particle | grains for electroconductive materials used in Example 4 is shown. The scanning electron micrograph of the particle | grains for electroconductive materials used in is shown.

Claims (12)

Functional material particles used to form a functional material,
Metal particles having an outer surface;
A first surface portion comprising a carbide of the metal formed in at least a region of the outer surface of the metal particles;
A functional material particle comprising: a second surface portion formed so as to extend outward from the first surface portion.   The particles for functional material according to claim 1, wherein the metal is aluminum or an aluminum alloy.   The functional material particle according to claim 1, wherein the second surface portion contains the metal and carbon.   The particle for a functional material according to any one of claims 1 to 3, wherein the second surface portion includes a carbide of the metal.   The functional material particles according to any one of claims 1 to 4, wherein the functional material is a conductive material.   The functional material particle according to any one of claims 1 to 4, wherein the functional material particle is a catalyst carrier particle.   The functional material particle according to any one of claims 1 to 4, wherein the functional material particle is a particle for an additive of a high temperature resistant material.   The functional material particle according to any one of claims 1 to 4, wherein the functional material particle is a methane generating material particle.   The functional material particle according to any one of claims 1 to 4, wherein the functional material particle is a filter material particle.   The functional material containing the particle | grains for functional materials of any one of Claim 1- Claim 9. A method for producing functional material particles used to form a functional material,
Disposing metal particles in a space containing a hydrocarbon-containing substance;
And a step of heating the metal particles to a melting point or lower of the metal.   The step of disposing the metal particles includes, after mixing the metal particles and the carbon-containing material, disposing a mixture of the metal particles and the carbon-containing material in a space containing the hydrocarbon-containing material. Item 12. A method for producing functional material particles according to Item 11.