JPS6140351A - Preparation of mixture of polyacetylene and graphite - Google Patents

Abstract

PURPOSE:To prepare the titled mixture having excellent processability, etc., and consisting of graphite covered with polycrystalline polyacetylene having beautiful metallic luster wherein the graphite and the polyacetylene can be made to be separable easily or bonded firmly with each other, by applying a polymerization catalyst to graphite, and contacting the graphite with acetylene. CONSTITUTION:A polymerization catalyst is applied to a graphite, and is made to contact with acetylene. The graphite is granular, solid, flaky, sheet, fibrous or powdery graphite selected from natural graphite, artificial graphite, thermal cracking graphite, and expanded graphite, and is preferably treated in purified hydrocarbon or ether. The ash content of the graphite is <=1.0wt%.

Description

[Detailed description of the invention] [Industrial application field] The present invention is a novel polyacetylene/graphite hybrid (polyacetylene/graphite hybrid, RAD material).
The product of the present invention relates to a method for producing a conductive material,
It is widely used in industrial materials and materials for daily miscellaneous goods, such as electromagnetic shielding materials, polar plates for plastic batteries, oxygen adsorbents, ion adsorbents, backing materials for water purification, and gaskets.

[Conventional technology]

Recently, various conductive polymer materials such as polyacetylene have been announced, and a number of electromagnetic shielding paints containing conductive fillers are also available on the market. Among them, there are a few conductive materials and dragon magnetic wave shielding materials that are simply mixed low-dimensional conductive substances with various inorganic powders, carbon materials, carbon fibers, etc. as composite materials.

The present inventors conducted a follow-up study on the conventional techniques related to these composites, and found that with respect to polyacetylene composites, composites equivalent to mere mechanical coating or mechanical mixing were obtained; The body generally lacked chemical stability, and its mechanical and physical properties were not sufficient, so it could not be used for a variety of purposes.

[Problem that the invention seeks to solve]

Here, the present inventors have conducted research on a method of directly inducing chemical reactions such as polymerization on various substrates as one method for overcoming the above-mentioned drawbacks.

As a result of numerous experiments, the present invention was finally completed by skillfully utilizing the properties of graphite, which has a special layered structure, as a base material. We have successively improved upon the deficiencies of existing polyacetylene films and polyacetylene composites, and have succeeded in producing a new polyacetylene/graphite composite suitable for a variety of uses.

[Means for Solving the Problem] and [Operation] The present inventors polymerized acetylene on the surface of graphite, thereby producing a hybrid body in which polyacetylene and graphite were integrated. Through many experiments, it was discovered that the polyacetylene film and polyacetylene composite are of excellent quality, eliminating the drawbacks of conventional polyacetylene films and polyacetylene composites, and the present invention was completed.

Furthermore, the present inventors applied a polymerization catalyst to graphite treated with ash content of 1.0% by weight or less in purified hydrocarbon or ether, and then brought it into contact with acetylene. It was discovered that a hybrid product could be produced and that this product was well suited for a variety of applications. Refined hydrocarbons are solvents that contain as little impurities as possible, such as water, sulfur compounds, alcohols, amines, chlorine compounds, and other active hydrogen atoms or heteroelements. There is no problem even if it is a mixture. Typical examples are propane, butane, pentane, hexane, and heptane.

Octane, gasoline, ligroin 2 petroleum ether.

Kerosene, light oil, liquid paraffin, cyclohexane, tetralin, decalin, benzene, toluene, xylene, polyalkylbenzene, alkylnaphthalene.

These include polyalkylnaphthalene, aromatic hydrocarbon mixed oil, etc.

In addition, purified ether is an ether from which impurities produced by-product during ether synthesis, such as water, alcohol, and sulfur compounds, have been removed as much as possible, and this ether can be a single substance or a mixture, and the above-mentioned There is no problem even if it is a mixture with hydrocarbons. Typical examples are dimethyl ether, methyl ethyl ether, diethyl ether, diisopropyl ether, dibutyl ether, cyamyl ether, dibenzyl ether, and tetrahydrofuran.

Dioxane, dioxolane, methyldioxolane.

Anisole, phenethol, diphenyl ether.

These include dicyclohexyl ether, silicate ester, silicone oil, etc.

The best graphite is one that does not contain any ash, but such materials are difficult to obtain naturally, so
Natural graphite that has been chemically purified to have an ash content of 1.0% by weight or less, particularly preferably 0.8% by weight or less, is suitable for the method of the present invention. Generally speaking, natural graphite has an ash content of 1
．． Many of them contain 5-8.0% by weight, and when their ash content was analyzed, the main component was 5iOz40-7
0% by weight, Al2O3 15-30% by weight, Fe2O
35-20% by weight, TiOzO, 3-2.0% by weight
, Ca00°2~5.0% by weight + MgO1~5.0
Weight%, K2O0.4-4.5% by weight, Na, 00
．． It is about 5 to 3.5% by weight. The present inventors have confirmed through many experiments that among these ash components, SiO□, CaO, K2O, and Na2O are particularly inconvenient for the method of the present invention. The preferred graphite used in the present invention is mineral graphite from which ash has been removed in advance by a chemical method, or graphite artificially prepared using a hydrocarbon raw material with a low ash content. It is. Furthermore, non-metallic impurities other than the above-mentioned metal oxides or silicates contained in graphite include water, halogen compounds,
Although there are sulfur compounds, phosphorus compounds, organic acids, tars, etc., the amount of these impurities present is often 3.0% by weight or less in total. It is highly desirable to remove these impurities as efficiently as possible. Regarding methods for removing these non-metallic impurities, the present inventors have developed a cleaning method,
I tried various extraction methods, vacuum treatment methods, firing methods, etc.
The best results have been obtained when graphite is treated in purified hydrocarbons or ethers to remove these non-metallic impurities by extraction or distillation methods. This solvent treatment is carried out under pressure, normal pressure or reduced pressure, and is generally 80 to 380°C, preferably 100 to 300°C.
．． It is carried out for 5 to 50 hours.

This heat treatment temperature and time are influenced by the type and content of nonmetallic impurities in graphite, and therefore should not be uniquely defined. Moreover, many experiments have shown that solvent treatment with substances other than the above-mentioned solvents is not suitable for achieving the method of the present invention.

In any case, through this treatment, non-metallic impurities other than the above-mentioned metal oxides or silicates contained between the graphite eyebrows are gradually moved outward and extracted, and at this time, the interlayers of the graphite structure are slightly expanded. Become. However, it is recognized that this tendency differs somewhat depending on the type of hydrocarbon or ether, but in general it appears that the interlayer expansion is more likely to occur with ethers than with hydrocarbons under the same conditions.

Now, attaching a polymerization catalyst to such treated graphite means the following operation.

First, as a polymerization catalyst attached to the graphite surface, Ziegler
Let's explain this using a binary catalyst such as a NAC catalyst as an example. Lower hydrocarbons (hexane, heptane.

or toluene, etc.) to titanium halide CTlC14.
or TiC1s] or titanate ester (Ti(O
R) When a catalyst solution is prepared by dissolving a) and the other component trialkylaluminum [8] (OR) 3) in advance and this is attached to graphite, a small portion of it will be inside the graphite. The majority of the particles are occluded, but most of them are attached to the surface of the graphite as if it were wet, and this can be done by repeatedly pressurizing the system, reducing pressure, and then normal pressure. In addition, when either a titanium compound solution or an alkyl aluminum solution is first attached to graphite, the catalyst solution easily penetrates into the glabella of the graphite and has the effect of slightly expanding the graphite. This effect seems to be remarkable when an ether solvent is used.This interaction of the catalyst solution with graphite is related to the shape, specific surface area, and processing conditions of graphite. In the case of artificial graphite, it is recognized that its appearance varies considerably depending on the degree of crystallinity of the graphite and the state in which its microcrystals are continuous.In any case, one of the catalyst components is inserted into the graphite. Later, when another component of the catalyst was added to wet the surface of the graphite and operated in the same manner as above, the reaction between these catalyst components gradually spread from the surface of the graphite to the inside, and the graphite itself became highly active. This method of depositing the catalyst can be easily applied not only to binary catalysts but also to ternary or higher catalysts.

The polymerization catalyst to be attached to graphite used in the present invention includes tetrabenzyl titanium as a single catalyst, and examples of binary catalysts include transition metal compound-tri-argylphosphine, transition metal compound-triallylphosphine,
Examples include transition metal compound-trialkyl aluminum, transition metal compound-sodium borohydride, transition metal compound-Grignard reagent, transition metal compound-organotin compound, and the like. These transition metal elements include titanium, vanadium, chromium, manganese, iron, cobalt, nickel, cobalt,
- Lopium.

Useful materials include neodymium, molybdenum, tungsten, and ruthenium. The chemical formula of a typical composition of these catalysts is Ti (CH2C6+(S) 4.N
1(Co) 3 P(C6H)3. TiC1
3-8] (CzHs)3. TiC] 4-8]
(C2H5)3. Ti(OCaHq)a-81(CzH
s)s, Ti(CHzCOCHzCOCH3)+
AI (CJs) +, Fe C1a C6) +5M
gBr, EuC1z-^1(C2)15)3. N
d(CH3COO)3-81(CzHs)*, Mo1
ls (CJs)4Sn, WCl6 (C6H5
) asn etc. These can be used alone or as a solution in an inert organic solvent, and in the case of a binary catalyst, a solution of each inert organic solvent can also be used. Examples of the inert organic solvent mentioned here include hexane, heptane, octane, cyclohexane, methylcyclohexane,
Benzene, Toruez, Xylene.

Dimethyl ether, diethyl ether, tetrahydrofuran, dioxane, dioxolane, ethylene glycol dialkyl ether, diethylene glycol dialkyl ether, crown ether, silicate ester, methyl orthoformate, ethyl orthoformate, dimethyl formal, diethyl formal, dimethyl acecool, diethylacecool etc. It was recognized that it is suitable for the invention.

After the catalyst described above is attached to graphite as described above, this graphite is made to exist in a reaction vessel by an appropriate method taking into account the shape of the polyacetylene/graphite hybrid to be synthesized. For example, when trying to obtain a polyacetylene/graphite hybrid film, a catalyst is attached to the surface of a graphite film or graphite sheet, and then placed at an appropriate location in a reaction vessel so that the temperature of the reaction can be easily controlled. . In addition, when graphite powder is used and a polyacetylene/graphite hybrid film is to be obtained, the graphite paste coated with a catalyst must be uniformly applied to the inner surface of the reaction vessel, the plastic film surface or the metal plate surface placed at an appropriate position. It is necessary to apply the

Further, in order to carry out suspension polymerization or gel polymerization, it is necessary to suspend graphite treated with a catalyst in inert '411 such as a hydrocarbon.

In any case, after the catalyst-coated graphite is present in the reaction vessel in a suitable manner, acetylene is added in the form of a gas (used alone or as a mixture with an inert gas) or in the form of a solution. (used after being dissolved in an inert solvent) into the reaction vessel. The reaction temperature is -80°C to +80°C, and the reaction time ranges from several minutes to several days, but it goes without saying that the setting of the reaction temperature and reaction time depends on the concentration of acetylene in the reaction system.

In the polyacetylene/graphite hybrid obtained by the method of the present invention, since the catalyst is present on the surface, glabellar surface, or inside of the graphite, the polyacetylene chains grow outward from the restricted part of the graphite, and the appearance is The graphite surface is covered with polyacetylene polycrystals that have a beautiful metallic luster. By adjusting the degree of adhesion of the catalyst,
For example, the polyacetylene/graphite hybrid can be shaped so that it can be easily peeled off from the graphite surface, or it can be shaped so that it is completely adhered to the graphite surface. The feature of this polyacetylene/graphite hybrid is that unlike a graphite composite where the surface of graphite is simply covered with a polyacetylene film, the ends of polyacetylene molecules are firmly sandwiched between the crystalline part of graphite. Even if it is easily peeled off, it is a beautiful polyacetylene/graphite hybrid. This is because the polymerization reaction of acetylene begins after the polymerization catalyst is completely captured and fixed by the graphite, in other words, it forms a microscopic solid bed, and the catalyst hardly moves during the reaction, so polymerization occurs. This ensures close adhesion later on. Of course, after the reaction is complete, contact treatment is carried out for a long time with a cold or hot solvent in order to elute and remove the polymerization catalyst or to complete the isomerization from the cis structure of polyacetylene to the trans structure. Even when completely removed, graphite microcrystals remain densely present in the polyacetylene/graphite hybrid. For this reason, the doped material promises better electrical properties than conventional polyacetylene doped materials, ease of subsequent molding, and improved mechanical properties.

〔Example〕

It has been revealed through many research experiments by the present inventors that the method of the present invention is an advantageous method for producing polyacetylene/graphite hybrids that are excellent as conductive materials. In order to explain the technical content, a few examples will be given below.

Example 1 A sulfuric acid-treated graphite sheet (high ratio 0.40 to 0.29, expansion rate 20 times, natural content 0.7% by weight, thickness Q, 5 mm, size 70 x 50 fl) was heated at 150 ml in a nitrogen stream. After heat treatment for 1 hour at ℃, the graphite sheet was placed in a Soxhlet extractor and heated for 48 hours to be extracted with purified toluene.

After the treated graphite sheet was allowed to stand at the bottom of a glass reaction vessel, 30 mIt of purified toluene was added and concentrated under reduced pressure until the amount of purified toluene became 10 mβ. Next, add 0.60ml of triethylaluminum to this toluene.
l.

Tetra (n-butyl) titanate 0.37 mI! , dissolve. Next, after repeating the reduced pressure operation and the normal pressure operation 5 times, the reaction vessel is cooled to -78°C. Next, purified acetylene gas was introduced into the reaction vessel, and after being left at -78°C for 30 minutes, washing was repeated with purified toluene cooled to below 0°C in a nitrogen atmosphere. The product is then dried to yield a glossy polyacetylene/graphite hybrid sheet. This product is a composite uniformly coated with polyacetylene that has a red copper-like dark brown metallic luster appearance, and the adhesion between graphite and polyacetylene is strong and resistant to breakage, making it suitable as an electrode for plastic batteries. .

Example 2 Expanded graphite sheet (electrical ratio 0.012 to 0.007, ash content 0.55 weight, thickness 0.2, size 70u+X25
The graphite sheet was calcined for 30 minutes at 300" C in an electric furnace in a nitrogen stream, and extracted with xylene for 50 hours in the same manner as in Example 1. The treated graphite sheet was then left at the bottom of a glass reactor. After that, 20m12 of purified decalin was added and immersed, and the decalin was concentrated under reduced pressure and heating to 8mj!.Next, the pressure was returned to normal in a nitrogen atmosphere, and 0.3mj! of triethylaluminum was dissolved, and the pressure was reduced again. Further, nitrogen is blown in to return to normal pressure, and then the pressure is reduced again. After repeating this process three times, the tetra(n
-Butyl) titanate (0.17 mff) is added to a solution of 2 mg of toluene. After repeating the process between reduced pressure and normal pressure three times, this was cooled to -78°C. Next, purified acetylene gas was gently introduced into the reactor and reacted for 2 hours, then washed with a toluene-methyl alcohol solution cooled to below 0°C in a nitrogen atmosphere for 5 hours and dried to form a polyacetylene/graphite hybrid. A sheet was obtained. This product had a metallic luster as in Example 1, and by adhering cellophane tape and peeling off the deteriorated portion of the surface, a composite sheet with a fresh active surface was obtained. This material exhibits good electrical conductivity by doping with iodine in the vapor phase. This composite sheet is conveniently used as a deoxidizing material in vacuum systems.

Example 3 Scale-like graphite powder (carbon content 99.9% by weight, ash content 0.1% by weight, specific surface area 1.50mm/g, average particle size 1μ) I
g to purified toluene 500m jl! After dispersing into
After boiling for 24 hours to extract impurities, collect
Dry under reduced pressure at 00°C for 10 minutes. Next, this was put into a flask and after adding purified toluene 81Ilβ and dispersing it, triethylaluminum 0.3mβ and tetra(n-butyl) titanate 0.17n+7! The paste is added and mixed well, and the reduced pressure-atmospheric pressure operation is repeated 5 times, and the resulting paste is uniformly applied to the inner surface of the reaction vessel and cooled to -60°C to -50°C. Next, purified acetylene gas was introduced into the reaction vessel, the reaction was continued for 60 minutes, and then washed in purified toluene cooled to below 0°C in a nitrogen atmosphere for 10 hours, and dried to form a polyacetylene/graphite hybrid film with metallic luster. was gotten. This material has excellent performance as an electrode for dry batteries.

Example 4 Sulfuric acid treated graphite sheet used in Example 1 (size 50w
5Qm) was calcined at 350° C. for 2 hours in a nitrogen stream, followed by hot extraction using n-hexane for 12 hours and dried. The graphite sheet is transferred to a glass reactor and soaked in n-hexane. Then n-hexane 5+
*N1(GO) to j2:+-P(CJs)z 0.5
Add the solution containing m#. Thereafter, the operation under reduced pressure and normal pressure was repeated four times to remove n-hexane, and then cooled to -78°C and purified acetylene mixed gas (acetylene/nitrogen =
1/3) was introduced and the reaction was carried out for 3 hours, followed by thorough washing with cold purified toluene. After drying the product, 100℃
When treated under reduced pressure for 5 hours, a polyacetylene/graphite hybrid C1- having a dark blue metallic luster was obtained. This product was suitable as an electrode for a sheet-shaped polyacetylene secondary battery.

Example 5 2 g of the flaky graphite powder used in Example 3 was dissolved in a nitrogen stream at 1
After drying at 20° C. for 10 hours, Soxhlet extraction was performed using heat-purified cyclohexane for 20 hours to remove soluble materials. Next, this graphite powder was transferred into a reactor, purified cyclohexane 7mA and Nd(CH3C00)3
- AI(CJs)s-C&H++OH catalyst 0.1ml
Add l and mix. Next, after repeating the reduced pressure-atmospheric pressure operation five times, the obtained black paste was uniformly applied to the inner surface of the reactor and cooled with a salt-ice cold agent. Next, purified acetylene gas is passed through the reactor, and a reaction is carried out for 4 hours to form a gelled product. When this gelled product is washed with a toluene-methyl alcohol mixture for 10 hours and dried, a polyacetylene/graphite hybrid film is formed on the inner surface of the reactor. The adhesion at the interface between polyacetylene and graphite in this product is extremely good, and by increasing the amount of raw material graphite, a bulky porous hybrid film can be obtained. Depending on the degree of porosity, such hybrid films can be used for various battery electrodes,
Used as a backing.

〔Effect of the invention〕

Methods of combining carbon-based materials and conductive polymers have been used in the past, but unless the raw materials and manufacturing conditions are limited, only a simple mixture or bonded product can be obtained, which is relatively expensive. It was not possible to take advantage of the properties of conductive polymers.

The present invention is the result of research to overcome this problem,
After applying a catalyst to a specific type of graphite, polyacetylene was allowed to grow, and it was confirmed that a homogeneous mixture was formed between polyacetylene and graphite. It has been revealed that the degree of mixing can be varied by modifying the manufacturing conditions.

Products obtained by the method of the present invention include electrodes, conductive materials,
It is easy to process into banking, ion adsorbents, water purification materials, pastes, paints, etc., and the completion of this invention has made it possible to put polyacetylene/graphite hybrids into practical use under economically advantageous conditions. Therefore, it can be said that the present invention has great effects when used industrially.

Claims (5)

[Claims] (1) A method for producing a polyacetylene/graphite hybrid, which comprises adhering a polymerization catalyst to graphite and then contacting it with acetylene. (2) The polyacetylene/graphite hybrid according to claim 1, wherein the graphite is at least one material selected from the group consisting of natural graphite, artificial graphite, pyrolytic graphite, and expanded graphite. Manufacturing method. (3) Claim 1 or Claims characterized in that the graphite is in the form of a solid, granular, flake, sheet, fibrous, or powder. 2. A method for producing a polyacetylene/graphite hybrid according to item 2. (4) The method for producing a polyacetylene/graphite hybrid according to any one of claims 1 to 3, wherein the ash content of the graphite is 1.0% by weight or less. (5) Claim 1, characterized in that the graphite is treated in purified hydrocarbon or ether.
A method for producing a polyacetylene/graphite hybrid according to any one of claims 4 to 4.