JPH026311A - Composite material of metallic carbide carbon and production thereof - Google Patents

Abstract

PURPOSE:To disperse ultrafine particles of a carbide of a metal such as Ti, V or Cr into a carbon matrix by coordinating a specific polymer compound having an atomic group of hydrocarbon base with the metal to give a compound and heat-treating the compound under a given condition. CONSTITUTION:A polymer compound which is provided with an atomic group of hydrocarbon base having coordination ability at a main chain and/or side chain and can be coordinated is prepared. The compound is coordinated with one metal selected from Ti, V, Cr, Mn, Zr, Nb, Mo, Hf, etc., or plural metals selected from these metals and Fe to give an organometallic polymer compound. Then the compound is heat-treated in an inert atmosphere at 400-2,000 deg.C. Consequently, a composite material of metallic carbide carbon wherein a carbide of the metal having <=5mum particle diameter is dispersed into a carbon matrix is obtained.

Description

[Detailed description of the invention] [Industrial use Banri P] The present invention relates to metal carbide carbon composite materials.

More specifically, the present invention relates to a composite material in which carbon material is the main component and metal carbide ultrafine particles are highly dispersed, and it can be used as a catalyst, conductive material, conductive material, electrode material, magnetic material, etc. It provides highly functional materials.

[Background Art and Problems to Be Solved] Currently, metal materials and carbon materials are being applied to a wide range of fields due to their diverse properties and abundance of resources. However, on the other hand, there are fields in which materials with even higher performance and functionality are desired, and more highly active materials are expected due to more precise material design.

Regarding metal carbide materials, there is a demand for materials that are more active as catalysts and have excellent operability, workability, and selectivity.

In addition to chemical stability, carbon materials have Uffi, heat resistance,
It has properties such as lubricity, good heat conductivity, and good electrical conductivity, and there are also carbon fibers that give formability and mechanical strength, and activated carbon that makes use of the properties that give it porosity. Such carbon fibers and activated carbon not only have a whitening effect, but also have great expectations for secondary uses such as use as an active site and as a reinforcing material.

Although it is thought that a carbon material in which metal carbides are uniformly dispersed is suitable for use in A, there has been no report on a raw material decomposition type method for producing HI3 in which metal carbides are uniformly dispersed.

[Means for Solving the Problems] The present inventors have arrived at the present invention as a result of decolorization research in order to solve the following two problems.

That is, the present invention provides Ti, V, Cr, Mn, Zr, Nb,
Mo.

The present invention provides a metal carbide carbon composite material in which a metal carbide component selected from the group of [-[, Ta, W, and Re] is dispersed in a carbon matrix as ultrafine particles. We also provide a metal-carbon composite material in which ultrafine metal carbide particle mixtures made of two or more metals selected from the group consisting of these metal components or Fe or ultrafine carbide particles made of different metals are dispersed. . Here, the term "carbide made of different metals" refers to a carbide in which part of the metal in a certain metal carbide has been replaced with a different metal.

It is essential that these ultrafine particle components have a particle size of 5 μm or less in order to achieve uniformity as a material, surface smoothness, and functions as a metal carbide, such as electrical conductivity, thermal conductivity, catalytic activity, etc. .

The present invention also provides a method for manufacturing such a metal carbide carbon composite material, in which the particle size and particle size distribution of dispersed particles can be controlled according to the purpose.

A specific method for producing these metal carbide carbon composite materials according to the present invention involves coordinating a metal to a polymeric compound having an atomic group having coordinating ability in its main chain and/or side chain. Metal polymer compound under inert atmosphere at 400℃~2
It is characterized by heat treatment at a temperature of 000°C. Further, the present invention is characterized in that an organometallic polymer compound obtained by polymerizing an organometallic compound that removes polymerizable functional groups is heat-treated at 400°C to 2000°C in an inert atmosphere.

Furthermore, the present invention is characterized in that these metal carbide components are uniformly dispersed, and are not agglomerated, precipitated or concentrated on the material surface or at the 7-trix grain boundaries. is important.

According to the production method of the present invention, it is possible to stably produce a carbon material in which ultrafine metal carbide particles having a particle size of 5 μm or less are uniformly dispersed with good reproducibility.

Ultrafine particles with O18m or less can be prepared with metals that are extremely difficult to produce using other vapor phase methods. Taking advantage of this point, it can be widely used in the preparation of various supported metal catalysts, high-density magnetic materials, sintered materials, chemical sensors, etc. In this specification, the particle size refers to the area average median diameter in an electron micrograph.

When beaten, the composite material of the present invention has high electrical conductivity (σ-108 cm
In addition to containing highly reactive metal carbide fine particles or low valence metal fine particles, it can adsorb organic molecules such as amines and alcohols.
By amplifying the current change at that time, it can be used as a sensor. In addition, it adsorbs various organic substances to attack the carbon skeleton, and at the same time decomposes or converts them into co-forms using the reducing ability and catalytic effect of metals, making it a deodorant.
It is a useful material. Furthermore, by selecting the metal species, it can be used as an excellent catalyst for polymerization and isomerization reactions of unsaturated hydrocarbons such as olefins, tsene, and alkynes, and by selecting the metal, it can be used as an oxidation or reduction catalyst. I can do it.

In the metal carbide carbon composite material of the present invention, the content of metal components is preferably 0.2 to 50%.

If the amount is less than this range, the function of the metal component will be relatively small and the effect of compounding will be weak, while if it exceeds this range, uniform dispersion will be difficult and the composite material which is the object of the present invention Not. The content can be selected depending on the purpose, but even if the content is within this range, it can be treated by, for example, performing slow oxidation as a post-treatment to partially remove the carbon portion, or by performing slow oxidation during the preparation of composite goods. Can be prepared. Such a method makes it possible to make the surface porous, making it possible to apply it in many directions.

The metal carbide carbon composite material of the present invention is obtained by firing a precursor metal polymer compound, and the metal carbide carbon composite material of the present invention is made by firing a precursor metal polymer compound. It is a coordination compound or a raw material.

This 61j molecular compound capable of coordination is a polymer compound having an atomic group having coordination ability in the main chain and/or side chain in the molecule, and is represented by the general formula as shown below. It is from et al.

(-L-)n- or -(-go-)nI.

The organometallic polymer compound formed by coordination to these metals is represented by the general formula below.

Here, L represents a group capable of coordinating, M represents a metal or an ion, X represents an auxiliary ligand, n represents a repeating unit of the polymer chain, and m represents the number of auxiliary ligands. represent.

1, -1vl bonds include π-, n-, and σ-coordination.

Examples of such coordinating polymer compounds are as follows.

That is, a) a polymer compound in which the metal is supported on a ligand consisting only of carbon atomic groups, for example, a chain and/or cyclic unsaturated bond in the polymer main chain and/or side chain; or iron and carbon have σ due to a substitution reaction
A polymer compound having a group capable of forming a bond and a ligand, specifically polybutanoene, polymonovinylacetylene, polybutanoene, polystyrene, polyvinylnaphthalene, polyvinylcyclopentadiene, polyvinylcyclopentadiene, vinylcitarooctadiene, polynovinylbenzene, polyisoprene, polychloroprene, polydiphenylbutadiene, polypentadiene, polyhexadiene,
Polydihynylacetylene, chloropolystyrene, chloromethylpolystyrene, poly[:3-[(vinyloxy)argyl]-1,3-pentanoene], poly[p-(cyclopentanoenylmethyl)styrene], poly[( (phenylmethyl)ethylene 1, etc., and these include homopolymers, alternating or block copolymers of these repeating units, and polymer compounds containing some of these repeating units in the polymer. , these polymer compounds include natural petroleum-based and coal-based pitches, lignin, and the like.

Another production method of the present invention is obtained by firing an organometallic polymer compound obtained by polymerizing an organometallic compound having a polymerizable functional group. Organometallic compounds having a polymerizable functional group are a group of compounds formed by coordinating a metal to an a-like compound consisting of a site with coordination ability and a site with polymerization ability, and the coordination format is , n-coordination, π-coordination, and σ-coordination.

Examples of compounds consisting of a site with coordinating ability and a site with polymerization ability are as follows: b) The site with coordinating ability mainly contains a ligand that causes a bond between a metal and a carbon atom or a carbon atomic group. b-1) having linear and/or cyclic unsaturated bonds, i.e., butadiene, monovinylacetylene, butanoin, styrene, vinylnaphthalene, vinylcyclopentadiene, vinylcyclooctadiene, divinylbenzene, isoprene, Chloroprene, diphenylbutadiene, pentadiene, hexadiene, divinylacetylene, vinylcyclopencnoene, p-pentagenylmethylstyrene, 2-cyclopentagenyelpropylene,
It includes derivatives such as 3-phenyl-1-propylene having a substituent such as halogen at the coordination site.

b-2) Those containing a ligand having a group capable of forming a σ bond through a substitution reaction between a metal and carbon, ie, chlorostyrene, chloromethylstyrene, etc.

Coordination to these metals is applied to general organometallic complex synthesis methods even if the ligand side is a high molecular compound shown in a) or a low molecular compound shown in b). method can be used. Namely, direct metalation reaction by substitution reaction of metal, substitution reaction with halide, metal-hydrogen exchange reaction using metal salt, metal-halogen exchange reaction by organometallic,
In addition to ligand exchange reactions, metals, metal salts, metal carbonyls,
Direct coordination of organometallic substances is possible.

Specific examples of the metal compounds according to the present invention include Metallic Sonotsuno et al., 'riC14, ZrC! 4. NbCl5
゜TaCIs, MoCI5. W Cla, T + (
On) 4, metal alkoxides, organometallic compounds such as metal acedelacetonate, and the like.

Polymers or crosslinked polymers of these polymerizable organometallic compounds, or copolymers or crosslinked polymers of these compounds and polymerizable monomers, or polymers, copolymers, or crosslinked polymers of these polymerizable organic metal compounds. The mixture is used as the precursor organometallic polymer compound in the present invention.As the polymerizable monomer that can be used together with the polymerizable organometallic compound, the compound having a polymerizable functional group used in the polymerizable organometallic compound is used. In addition to compounds uncoordinated to the metal of the ligand, common monomers can be used.

That is, common olefins include ethylene, propylene, butenes, isobutylene, cyclobutene, cyclopentene, chlorohexene, cycloheptene, chlorooctene, etc., and acetylenes include acetylene,
Examples include methylacetylene, probylacetylene, and phenylacetylene.

Furthermore, there are halogenolefins such as vinyl chloride, vinylidene chloride, vinyl bromide, and vinyl fluoride, as well as vinyl esters such as vinyl acetate, styrene, α-methylstyrene, divinylbenzene, chlorostyrene, vinylnaphthalene, and vinylanthracene. , aromatic vinyl compounds such as acenaphthylene, etc.

The metal carbide carbon composite material of the present invention is made by firing organometallic a-organic polymer compounds obtained by the two methods described above, and the metal components forming these are Ti, V, and Cr. , Mn ZrNb, Mo, l-1''
, Ta, W, and Re can be used, and particularly preferred metal species may be mentioned depending on the type of the ligand. That is, the ligands and coordination types in the organometallic polymer compound of the precursor that provides the metal-carbon composite material are mainly Cr, Mo, and W of the Vla group as bonds with alkyl and allyl. 2) Chloropenta π with gen or pentagenyl
As those forming the coordination, ■a group TiZr, Hf,
V, Nb, and Ta of the Va group; Cr and Mo of the Vla group.

W1■a group Mn, Re 3) Ti, V and Vl as π-coordinated to the aromatic ring
Precursor polymers can be formed, such as metal-carbon composites (materials such as A-group Cr, MoW, etc.).

In these coordination compounds, metal coordination causes detachment or rearrangement of hydrogen ions in the ligand, redox of the ligand itself, etc., resulting in new electron configurations in the molecule or coordination. Although the valence and ionicity of the metal may vary, such metals can also be used as starting materials for the metal carbide carbon composite material of the present invention. In the above examples, some coordination compounds are also shown.

Such perforated metal compounds have excellent shapeability, and it is possible to mold the precursor polymer into the desired shape of the final metal carbide carbon composite material using various molding methods. In addition to general molding methods such as pressure molding, extrusion molding, and injection molding as a bulk body, spinning by controlling the molecule In,
Can be made into sheets and thin films.

The metal carbide carbon composite material of the present invention can be obtained by firing the metal-containing precursor polymer obtained as described above under temperature conditions suitable for each metal.

Firing is usually performed at normal pressure in an inert gas atmosphere such as nitrogen or argon, but depending on the oxidizing properties and reactivity of the organometallic, reducing gases such as hydrogen may be used, or lo
Firing is required under pressure around ooatm or under reduced pressure.

The firing temperature is usually preferably 400 to 2000°C. Furthermore, since the organic matter is fired, it is necessary to control the temperature increase during thermal decomposition. Especially in this ascending 1117L process,
Since the thermal decomposition of 7-trinox may involve polymerization, it is necessary to avoid abnormally generated heat. For this reason, it is desirable that the temperature increase rate be within the range of 0.01 to b.

Furthermore, it may be possible to improve productivity by performing heat treatment to the degree range at the initial carbonization stage 711, followed by pressure molding, and then heat treatment again.

The constant temperature holding time at the final treatment temperature is 50 hours or more.
Desirable time 1. The structure and composition of the metal-carbon composite material obtained in the following-1- were identified and confirmed.

The raw material polymer compounds and metal compounds are measured using an infrared spectrophotometer (IR), nuclear magnetic resonance (NMR), which is used to determine the structure of general organic compounds and organic metal compounds.
The structure was determined by elemental analysis and spectroscopic methods such as ultraviolet spectroscopy (UV).

Thermogravimetric analysis was performed during the firing process to observe the loss of rim due to the thermal decomposition process. To identify metal-containing chemical species in the fired product, powder X-ray diffraction (Xr(D) measurement, selected area electron diffraction (SAD)) or electron microbeam diffraction (
MBD) was used. Regarding the identification of iron carbides, Mössbauer spectroscopy was used in combination. The macroscopic distribution and dispersion state of metal carbides in the fired product were examined using a scanning electron microscope (SE).
M) image and an X-ray microanalyzer (EPMΔ) image.

Furthermore, the microscopic distribution of metal carbides, the state of dispersion, and the state of carbon in the matrix were observed using transmission electron microscopy (TEM) images, and the distinction between metal carbides and carbon in the matrix was made using an energy dispersive X-ray diffraction device (El). ) according to

[Examples] The present invention will be explained in more detail with reference to Examples below, but the following examples are merely examples, and the scope of the present invention is not limited thereby.

(Example 1) Saw blade, Borisjilene and Cr(Co)e[0
2 moles per monomer unit] were reacted.

After refluxing for 48 hours, hexadiene was added to precipitate the mixture.

The crude reaction was kept under vacuum at 60°C for 24 hours.

As a result of elemental analysis, approximately 5% of the benzene rings of styrene were bonded with Cr(CO)3 units (boris styrene).
It was found that it was a Cr(CO)+ complex. This polymer was calcined in a high-purity argon stream passed through a P, 05 column (1000 °C
When the temperature was raised to .degree. C., maintained for 2 hours, and then allowed to cool, a black carbon composite material with a glossy surface was obtained. It was confirmed by TEM image observation that particles with a particle size of 1100 to 300 nm were dispersed in the carbon matrix.

According to the EDX spectrum at each point, the phase separation between the ultrafine chromium compound particles and the carbon substrate was good. XRD pattern (
From FIG. 1), it was found that the chromium compound was ultrafine particles of Cr+C2.

[Brief explanation of the drawing]

FIG. 1 is a diagram showing a powder X-ray diffraction (XRD) pattern of the material of Example 1.

Claims (1)

[Claims] 1. A metal carbide carbon composite material in which a metal carbide component is dispersed in a carbon material mainly composed of carbon, wherein the metal carbide component is Ti, V, Cr, Mn, Zr, Nb, Mo, H
A metal carbide carbon composite material, which is ultrafine metal carbide particles having a particle size of 5 μm or less and made of one type of metal carbide selected from the group consisting of f, Ta, W, and Re. 2. In a metal carbide carbon composite material in which a metal carbide component is dispersed in a carbon material whose main component is carbon, the metal carbide component is Ti, V, Cr, Mn, Fe, Cu, Zr, N.
A metal-carbon composite which is a metal carbide ultrafine particle mixture with a particle size of 5 μm or less consisting of carbides of two or more metals selected from the group consisting of b, Mo, Hf, Ta, W, and Re, or ultrafine particles of carbides made of different metals. material. 3. Ti, V
, Cr, Mn, Zr, Nb, Mo, Hf, Ta, W, R
one selected from the group consisting of e or those metals and F
An organometallic polymer compound obtained by coordinating two or more metals selected from the group consisting of e is heated at 400°C under an inert atmosphere.
The method for producing a metal-carbon composite material according to claim 1 or 2, characterized in that the heat treatment is performed at a temperature of ~2000°C. 4, Ti, V, Cr, Mn, Zr, Nb, Mo, Hf,
Polymerization having a hydrocarbon-based ligand coordinated with one selected from the group consisting of Ta, W, and Re, or two or more metals selected from the group consisting of these metals and Fe, and a polymerizable functional group. A polymer or copolymer obtained by polymerizing one or more types of organometallic compounds, or a mixture of these polymers or copolymers under an inert atmosphere for 40 minutes.
The method for producing a metal composite material according to claim 1 or 2, wherein the heat treatment is performed at a temperature of 0°C or higher and 2000°C or lower. 5, Ti, V, Cr, Mn, Zr, Nb, Mo, Hf,
Polymerization having a hydrocarbon-based ligand coordinated with one selected from the group consisting of Ta, W, and Re, or two or more metals selected from the group consisting of these metals and Fe, and a polymerizable functional group. A mixture of a copolymer or a crosslinked polymer obtained by copolymerizing one or more organic metal compounds and a hydrocarbon polymerizable monomer that can be copolymerized with the organic metal compound is heated at 400°C or higher in an inert atmosphere. The method for producing a metal-carbon composite material according to claim 1 or 2, characterized in that the heat treatment is performed at a temperature of 2000° C. or lower.