JPH026310A - Composite material of metallic oxide carbon and production thereof - Google Patents

Abstract

PURPOSE:To disperse ultrafine particles of an oxide of a metal such as Ti, V or Cr into a carbon matrix by coordinating a specific polymer compound having an atomic group containing oxygen atom 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 having coordination ability containing oxygen atom at a main chain and/or side chain and can be coordinated is prepared. The compound is coordinated with one or more metals of Ti, V, Cr, Mn, Zr, Nb, Mo, etc., 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 oxide carbon wherein an oxide of the the metal having <=5mum particle diameter is dispersed into a carbon matrix is obtained.

Description

[Detailed description of the invention] “Industrial application field” The present invention relates to metal oxide carbon composite materials.

More specifically, the present invention relates to a composite material in which a carbon material is the main component and ultrafine metal oxide particles are highly dispersed. It provides functional materials with excellent functionality.

[Prior art and problems to be solved] At present, metals of the H family and carbon materials are being applied to a wide range of fields due to their diverse properties and the abundance of resources. However, on the other hand,
Among these fields, there are fields where even higher performance and functionality are desired, and more highly active materials are expected due to more precise material design.

Regarding metal oxide materials, for example, there is a need for materials that are more active as catalysts and have excellent operability, workability, and selectivity, and as magnetic materials, there is a need for magnetic layers and magnetic powders that can record at higher density. There is.

In addition to chemical stability, carbon materials have properties such as light weight, heat resistance, lubricity, good heat conductivity, and good electrical conductivity. There are activated carbons, etc. that can make use of the properties that give them properties. Such carbon fibers and activated carbon are not only effective in themselves, but also have great expectations for their secondary uses, such as their use as active sites, reinforcing materials, and the like.

Although carbon materials in which metal oxides are uniformly dispersed are thought to be useful, there are no carbon materials in which the metal oxides are uniformly dispersed, and there is no method to create materials in which metal oxides are uniformly decomposed using a raw material decomposition type. Not reported.

[Means for Solving the Problems] The present inventors have arrived at the present invention as a result of intensive research to solve the above-mentioned problems.

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

The present invention provides a metal oxide carbon composite material in which an oxide component of a metal selected from the group of H, Ta, W, and Re is dispersed in a carbon matrix as ultrafine particles. The present invention also provides a metal-carbon composite material in which a mixture of ultrafine metal oxide particles made of two or more metals selected from the group consisting of two or more metals or ultrafine particles of oxides made of different metals are dispersed. An oxide is an oxide in which part of the metal in a certain metal oxide is replaced with a different metal.

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

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

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

Furthermore, the present invention is characterized in that these metal oxide components are uniformly dispersed, and it is important that they do not aggregate, precipitate, or concentrate on the material surface or matrix grain boundaries. It is.

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

In particular, ultrafine particles of 0.1 μm or less can be prepared even from metals that are extremely difficult to manufacture by Ike's vapor phase method. 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. Incidentally, in this specification, the diameter refers to the area average median diameter in an electron micrograph.

Moreover, the composite material of the present invention has high electrical conductivity (σ-10Scm
- In addition to containing more than 100% of ions, it also contains highly reactive metal oxide fine particles or low-valence metal fine particles, so it can adsorb organic molecules such as amines and alcohols, and the current at that time It can be used as a sensor by amplifying changes. In addition, because it has a carbon skeleton, it adsorbs various organic substances, and at the same time decomposes or reduces them using the reducing ability of metals and catalytic effects, making it an advantageous deodorant. Furthermore, by selecting the metal species, it can be used as a catalyst for the polymerization and isomerization reactions of unsaturated hydrocarbons such as olefins, enenes, and algines. Can be used as a catalyst.

In the metal oxide carbon composite material of the present invention, the content of the metal component is preferably 02 to 50% by weight.

If the amount is less than this range, the function of the metal component will be relatively small and the meaning of composite will be diminished, while if it exceeds this range, uniform dispersion will be difficult and the composite material targeted by the present invention will not be obtained. The content can be selected depending on the purpose, but if it exceeds this range, it can be prepared by, for example, performing slow oxidation as a post-treatment to partially remove the carbon part, or by performing slow oxidation during composite material preparation. . Such a method also makes it possible to make the surface porous, making it possible to apply it to many fields.

The metal oxide carbon composite material of the present invention is made by firing several metal polymer compounds of planar precursors as described above,
The raw material is a coordination compound of the polymer compound that can be used and a metal.

This coordinating polymer compound refers to the main chain and/or
Alternatively, it refers to a polymer compound with an atomic group having coordination ability in its side chain, and is represented by the general formula as shown below.

(-L-)n- or -(-go-)nThe metal polymer compound formed by coordination to these metals is shown by the general formula below.

Here, I7 represents a group with coordination ability, M is a metal or ion, X is an auxiliary ligand, n is a repeating unit of the polymer chain, and m represents the number of auxiliary ligands. . The oxygen atom may be contained in any part of this polymer compound.

Basically, the oxygen atom is generally located in I7, but may also be present in the polymer chain or the auxiliary ligand (X). In that case, the LM bond includes a π-coordination, an n-coordination, and a σ-coordination.

Examples of polymer compounds capable of such coordination are as follows.

That is, a) a polymer compound in which a 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 a ligand having a group that allows a metal and carbon to form a σ bond through a substitution reaction, specifically polybenzyl acrylate, polynovinyl ether, polyallyl. Vinyl ether, polydivinyl ketone, polydiallyl phthalate, poly(
polypentadienyl alkyl acrylate), poly[
(phenylalkyl)acrylate], poly[(phenylalkyl)methacrylate], poly[(pentagenyl)acrylate], etc., and these are homopolymers, alternating or block copolymers of these repeating units, and polymers. It contains polymeric compounds that partially contain these polymerized repeating units. These polymeric compounds include natural petroleum-based and coal-based bits, lignin, and the like.

Furthermore, (b) is a polymer compound having an atomic group having 0 atoms as a ligand that coordinates with a metal, specifically, as a ligand, oxytum, alcohol, phenol, sugar, carboxylic acid, ketone, It is a polymer compound having an atomic group such as a diketone, and more specifically, for example, poly[oquinonoalkylmethyl)ethylene], poly(1-hydroxyethylene), poly[l-(hydroxymethyl)ethylene], poly[ 1-(p-hydroxyphenyl)ethyleneco, cellulose, poly(l-carboquinoethylene), poly(I-carboxy-1-methylethylene), poly[+ -(1,
3-nocarponylbutyl)ethylene], poly(1-salicyloxyethylene), poly(acryloylhydroxamine), poly(1,6-D-glucobylanose), poly(l
, 3-dioxohexamethylene), and these homopolymers, alternating, block or random copolymers of these polymerized repeating units, and polymers in which some of these polymerized repeating units remain in the polymer. Contains compounds. In addition to these mainly addition polymerization and ring-opening polymerization products, it also includes condensation polymer compounds such as unsaturated polyesters, phenolic resins, and nylon.

Another method for producing a leading metal polymer compound is to obtain it by firing an organometallic polymer compound obtained by polymerizing an organometallic compound having a polymerizable functional group. An organometallic compound having a polymerizable functional group is
A group of compounds formed by coordinating a metal to an organic compound consisting of a site with coordination ability and a site with polymerization ability, and the coordination formats are n-coordination, π-coordination, and σ-coordination. Examples of compounds consisting of a site with a coordinating ability and a site with a polymerization ability are as follows: c-1) having a chain and/or cyclic unsaturated bond, i.e., benzyl acrylate, dihinyl ether, allyl vinyl ether, nohinyl ketone, noaryl phthalate, pentagenylalkyl acrylate, Ncropentadienyl alkyl acrylate, phenylalkyl acrylate, phenyl alkyl methacrylate, cyclopentadienyl alkyl methacrylate, cyclooctagenylacrylate, etc., including derivatives with substituents such as halogens in the coordination site.

Also, d) What is an atomic group whose moiety having ligand ability has an O atom? Specifically, the coordination atomic group is an atomic group such as oxime, alcohol, phenol, sugar, carboxylic acid, ketone, diketone, etc. More specific examples include vinyl alcohol, propenyl alcohol, hydroxyethylene, acrylic acid, methacrylic acid,
-propenol, I)-[(N,N-dimethylcarboxy)methylethylene, vinyl salicylate, and the like.

Coordination to these metals can be done with general organometallic complexes, even if the ligand side is a high molecular compound shown in a) and b) or a low molecular compound shown in c) and d). Methods applied to synthetic methods may be used. Namely, in addition to direct metalation reactions with metal substitution reactions, substitution reactions with halides, metal-hydrogen exchange reactions using metal salts, metal-halogen exchange reactions with organic metals, and ligand exchange reactions, metals and metal salts,
Direct coordination of metal carbonyls, organometallics, etc. is also possible.

Specific examples of the metal compounds according to the present invention include metal sono, T+CI4. ZrCl4. NbCl5゜TaCIs, MoC15, WC1,, Ti(OR)4
．． Examples include organometallic compounds such as metal alkoxides and metal acedelacetonates.

Polymers or copolymers of these polymerizable organometallic compounds, copolymers or crosslinked polymers of these compounds and polymerizable monomers, or mixtures of these polymers, copolymers, or crosslinked polymers is used as a precursor organometallic polymer compound in the present invention. Polymerizable monomers that can be used with the polymerizable organometallic compound include compounds that are not coordinated with the metal of the ligand having a polymerizable functional group used in the polymerizable organometallic compound, and general monomers can be used.

That is, common solenoids include ethylene, propylene, butenes, isobutylene, cyclobutene, noclobentene, cyclohexene, sochlorohebutene, cyclooctene, etc., and acetylenes include acetylene,
Examples include methylacetylene, propylacetylene, 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, aminostyrene, and hydroxostyrene. etc., aromatic vinyl compounds such as vinylnaphthalene, hinyl anthracene, acenaphthylene, vinyl salicylate, etc., edylhinyl ether,
Alkyl astringent aromatic vinyl ethers such as phenyl vinyl ether and propyl vinyl ether; acrylic acid and acrylic acid esters such as α-ananoacrylic acid ester and α-halogenoacrylic ester; methacrylic acid and methacrylic acid esters such as medyl methacrylate; In addition to acrylamides such as methacrylamide, noacetone acrylamide, vinyl ketones such as medyl vinyl ketone and phenyl vinyl ketone, vinyl Examples include pyridine and vinyl imidazoles.

The metal oxide carbon composite material of the present invention is made by firing organometallic polymer compounds obtained by the three methods described above, and the metal components forming these are Ti, V , Cr, Mn, Zr.

Although Nb, Mo, 1-Ir, Ta, W, and Re can be used, 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 1) π-coordinated to the aromatic ring via an O atom; Group Cr, Mo, W.

2) As a group to which the alkogino group is coordinated, '' of the IVa group
In addition to I"i, Zr, and I-1f, 3) those having a carboxyl group coordinate include Ti of group IVa,
Zr, I, etc. can also form precursor polymers that are particularly excellent as metal-carbon composites.

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. In some cases, the valence and ionicity of the metal used may vary, and such materials can be used as the starting material for the metal oxide carbon composite material of the present invention. Some of such coordination compounds are also shown in the above examples.

Such n-machine metal compounds are highly formable, and the precursor polymer can be molded into the desired shape of the final metal oxide carbon composite 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 molecular weight,
It is possible to make it into a notebook and a thin film.

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

Firing is usually carried out at normal pressure in an inert gas atmosphere such as nitrogen or argon, but depending on the oxidizing properties and reactivity of the a-type metal, a reducing gas such as hydrogen may be used, or in some cases 10
Firing is required under pressure or reduced pressure around 0Qa.

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. Particularly in this lifting and packing process, thermal decomposition of the matrix may accompany polymerization, so it is necessary to avoid constantly generated heat. For this reason, the heating rate was set to 0.0
It is desirable to carry out within the range of 1 to picC/min.

Furthermore, productivity may be improved by performing pressure molding after heat treatment to the carbonization initial temperature range and heat treatment again.

The constant temperature holding time at the final treatment temperature is preferably 0.5 hours or up to 250 hours. The structure and composition of the metal-carbon composite material obtained as described above were identified and confirmed. That is, the raw material polymer compounds and nT metal compounds can be used to determine the structure of general multilayer compounds and a metal compounds.Infrared spectrophotometer (In), nuclear magnetic resonance (NMIN),
The structure was determined by elemental analysis and spectroscopic methods such as ultraviolet spectroscopy (UV).

Thermogravimetric analysis was conducted during the firing process to observe the reduction in usage due to the thermal decomposition process. To identify metal-containing chemical species in the fired product, powder X-ray diffraction (XRD) measurement, selected area electron diffraction (SAD), or electron macrobino diffraction (M
13D) was used. For the identification of iron oxides, Mössbauer spectroscopy and other techniques were used.

The macroscopic distribution and dispersion state of metal oxides in the fired product were analyzed using a scanning electron microscope (SEM) image and an X-ray microanalyzer (EPMA) image.

Furthermore, the microscopic distribution of metal oxides, the dispersion state, and the state of carbon in the matrix are observed using a transmission electron microscope (TEM), and the distinction between metal oxides and carbon in the matrix is made using an energy dispersive X-ray diffraction device (EDX). ) 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 do not limit the scope of the present invention.

(Example 1) 5w of polyvinyl alcohol (saponification degree 88-90%)
A t% aqueous solution was prepared. 3.0 g (0.05 molar equivalent/monomer unit) of ZrC1 was added little by little to 250 g of the aqueous solution with stirring.

Aqueous ammonia was added to the mixture until the mixture became slightly alkaline, and then stirred at room temperature for 24 hours. When this solution was poured into a large amount of acetone, a colorless polymer precipitated. After purification by reprecipitation and drying, a colorless polymer complex having Zr-◯ bonds was obtained. The yield is almost constant. Bis(cyclopentadienyl) Z r Cl t instead of ZrCl4
, TiCl4, bis(cyclopentanoenyl)TiCl
2. When NbCl5 and TaCl5 are added, M-
0 (where M=Zr, TiNb or Ta) bonds similar polymer complexes were obtained.

The above polymer was heated at 1000°C (2 hours;
It was fired at an average temperature increase rate of 03°C/m1n).

a) Polyvinyl alcohol-ZrCI4-xt: X=0
~3) Complex heat-treated product calcination yield 25.5%, C: 64.45, H: 0, 4
8. Zr: 22.53%. It was confirmed from the TEM image that the ultrafine metal compound particles were extremely uniformly dispersed in the carbon matrix. Based on the Xr(D measurement), this metal compound can be attributed to ZrCO2 in the cubic system (high temperature stable phase). The carbon substrate is amorphous (Figure 1).

b) Polyvinyl alcohol-bis(cyclobentanonyl)ZrC12-x(x・0~l) complex heat-treated product T E
From the M image, it is confirmed that very fine particles of several nm or less are dispersed in the carbon matrix. FIG. 2 shows an XRD diagram. Peaks of amorphous carbon and Zr02 (cubic crystal) are observed.

C) Polyvinyl alcohol-TiC14-x complex heat-treated product 0.69. +8, I-1+ 0, 39, Ti:18.
TEM image observation revealed that 11% extremely fine metal compound particles were dispersed in the carbon matrix (amorphous). , XRD pattern shows that titanium oxide is produced.

(Example 2) Polyacrylic acid (average molecular weight: 250.000) was dissolved in a mixed solvent of ethanol and water.

By adding 0.10 equivalent of sodium hydroxide to the monomer unit, 10% of the monomer unit of polyacrylic acid could be converted into sodium acrylate salt.

While sufficiently stirring, TiCl4 was added dropwise in an amount of 0.05 equivalent to the monomer unit, and the mixture was stirred at 30° C. for 24 hours. When the concentration was high, it became gel-like at this stage.

After adding a large amount of benzene and separating the precipitated gel-like polymer, drying and washing with water were repeated. A colorless polymer is obtained. Z rCI4, bis(cyclopentagenyl)Ti
CL, his (cyclopentagenyl) Z r Cl
The same was true for t.

The above polymer complex was heat-treated at 1000° C. in an argon stream.

Bo') 7 ') ') Lucic acid-T + CI4-X
(X・O~3) Firing yield of fired body 22.7% From the black powder XRD pattern (Fig. 3), titanium in this composite is TLO3, oa (60%) Ti30. It was confirmed that it existed in the form of (40%). The carbon substrate was amorphous.

[Brief explanation of the drawing]

Figure 1 shows polyvinyl alcohol-Z obtained in Example 1.
It is a figure which shows the powder X-ray diffraction (XRI) pattern of rCI4-x (X*O~3) complex heat-treated product. Figure 2 shows the polyvinyl alcohol-bis(cyclopentagenyl) ZrCI2-X (X=O~
1) It is a diagram showing the XRD pattern of the heat-treated complex. Figure 3 shows polyacrylic acid TiC14 obtained in Example 2.
-X (X=0-3) It is a figure showing the XRD pattern of the fired body.

Claims (1)

[Claims] 1. In a metal oxide carbon composite material in which a metal oxide component is dispersed in a carbon material whose main component is carbon, the metal oxide component is Ti, V, Cr, with a particle size of 5 μm or less, Mn, Zr
, Nb, Mo, Hf, Ta, W, and Re. 2. In a metal oxide carbon composite material in which a metal oxide component is dispersed in a carbon material whose main component is carbon, the metal oxide component is Ti, V, Cr, Mn, Fe with a particle size of 5 μm or less.
, Cu, Zr, Nb, Mo, Hf, Ta, W, Re, a mixture of metal oxide ultrafine particles consisting of oxides of two or more metals, or ultrafine particles of oxides consisting of different metals. Metal oxide carbon composite material. 3. Ti, V
, Cr, Mn, Zr, Nb, Mo, Hf, Ta, W, R
A claim characterized in that an organometallic polymer compound obtained by coordinating one or more metals selected from the group consisting of 3. A method for producing a metal oxide carbon composite material according to 1 or 2. 4. O that has a polymerizable functional group and can coordinate to metals
Ti, V, Cr, Mn, Zr, Nb in atomic groups containing atoms
, Mo, Hf, Ta, W, Re, or a polymer obtained by polymerizing one or more organometallic compounds coordinated with one or more metals selected from the group consisting of , Mo, Hf, Ta, W, and Re. or a mixture of these polymers or copolymers under an inert atmosphere at 400°C or higher for 2000°C.
3. The method for producing a metal composite material according to claim 1, wherein the heat treatment is performed at a temperature of .degree. C. or lower. 5. O that has a polymerizable functional group and can coordinate to metals
Ti, V, Cr, Mn, Zr, Nb in atomic groups containing atoms
, Mo, Hf, Ta, W, Re, and one or more organometallic compounds coordinated with one or more metals selected from the group consisting of: A mixture of copolymers or crosslinked polymers obtained by copolymerizing with monomers at 400°C or higher and 2000°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 below. 6, Ti, V, Cr, Mn, Zr, Nb, Mo, Hr,
One or more metals selected from the group consisting of Ta, W, and Re are bonded to the polymer chain via a σ- or π-bonding carbon, and a heavy metal containing an O atom in addition to the metal coordination site is used. The method for producing a metal oxide carbon composite material according to claim 1 or 2, characterized in that the combination is heat-treated at a temperature of 400° C. or higher and 2000° C. or lower in an inert atmosphere. 7. Ti, V, Cr, Mn, Zr, Nb, Mo, Hr,
One or more metals selected from the group consisting of Ta, W, and Re are bonded to the polymer chain via a σ- or π-bonding carbon, and at least one of the auxiliary ligands of the metal 3. The metal oxide carbon composite material according to claim 1 or 2, wherein the polymer in which O atoms are bonded to metals is heat-treated at a temperature of 400°C or higher and 2000°C or lower in an inert atmosphere. Production method.