JP2992630B2 - Graphite-polymer composite and method for producing the same - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] The present invention relates to a novel inorganic-organic composite and a method for producing the same.

[0002]

2. Description of the Related Art Graphite intercalation compound (Graphite Intercalation Compound;
It is known that, when a specific hydrocarbon such as benzene or ethylene is brought into contact with (GIC), these hydrocarbons are intercalated between graphite layers to form a ternary GIC. For example, when benzene is intercalated and left as it is or heated, an oligomer is formed and a graphite-oligomer composite is obtained. Also, GI with a small amount of ethylene intercalated
In C, it has also been reported that a small amount of polymer corresponding to the amount of intercalate is formed between graphite layers ("Introduction to New Carbon Materials", Realize Inc. (1996),
pp 157-162).

[0003] However, there is no known technology for producing a graphite-polymer composite having a high polymer content by introducing a large amount of unsaturated hydrocarbon into GIC and causing polymerization.

[0004]

SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide a new technique capable of producing a graphite-polymer composite having a high polymer content.

[0005]

Means for Solving the Problems The inventors of the present invention have conducted research to achieve the above object, and as a result, have introduced an easily polymerizable unsaturated hydrocarbon between graphite layers of GIC, and then polymerized the unsaturated hydrocarbon. As a result, a graphite-polymer composite having a high polymer content and novel characteristics was successfully manufactured.

That is, the present invention provides the following graphite-polymer composite and a method for producing the same: A graphite-polymer composite that holds a polymer between graphite layers of an alkali metal-graphite intercalation compound.

[0007] 2. A method for producing a graphite-polymer composite, comprising introducing an unsaturated hydrocarbon between graphite layers of an alkali metal-graphite intercalation compound and polymerizing the unsaturated hydrocarbon using an alkali metal as a catalyst.

[0008] 3. After introducing an unsaturated hydrocarbon between the graphite layers of the alkali metal-graphite intercalation compound and polymerizing the unsaturated hydrocarbon using the alkali metal as a catalyst, the obtained graphite is obtained.
A method for producing a graphite material, comprising heat treating a polymer composite.

[0009]

BEST MODE FOR CARRYING OUT THE INVENTION Used as a raw material in the present invention
GIC is a known material obtained by reacting graphite with an alkali metal. GIC is referred to as potassium-GIC (or K-GIC) depending on the species intercalated between the graphite layers, for example, when the species is potassium. Also, depending on the intercalated chemical species and its abundance, it is called, for example, KC ₈ , KC ₂₄ , KC _36, or the like.

In the method of the present invention, the unsaturated hydrocarbon is brought into contact with the GIC under reduced pressure to introduce a polymerizable unsaturated hydrocarbon between the graphite layers.

[0011] As long as the GIC is intercalated with an alkali metal, there is no particular limitation on the kind and the amount of the alkali metal. In the following description, K-GI
G is represented by C, but in the present invention, other alkali metal-graphite intercalation compounds can also be used,
Needless to say.

In the present invention, the easily polymerizable unsaturated hydrocarbon means an unsaturated hydrocarbon which polymerizes in the presence of a polymerization initiator at room temperature (about 25 ° C.) and under a mild condition of 1 atm or less. . Examples of such unsaturated hydrocarbon include isoprene and styrene which are liquid at normal temperature and atmospheric pressure; and 1,3-butadiene which is gas at normal temperature and atmospheric pressure. Benzene, ethylene and the like described in the above-mentioned known documents cannot be used in the present invention because they do not polymerize under such mild conditions.

The introduction of unsaturated hydrocarbon (hereinafter referred to as "monomer") between the graphite layers of K-GIC is carried out in a reduced pressure vessel.
GIC and the monomer are allowed to coexist at room temperature.
More specifically, when using a gaseous monomer at normal temperature and atmospheric pressure, for example, the pressure in a container containing K-GIC is usually 10 ⁻² Torr or less (≦ 10 ⁻² Torr), more preferably Is 10 ^-3
The monomer is supplied at a pressure of Torr or less (≦ 10 ⁻³ Torr). In addition, when a liquid monomer is used at normal temperature and atmospheric pressure, for example, the inside of a container containing K-GIC is usually 10 ^-2 Tor
r or less (≦ 10 ⁻² Torr), more preferably 10 ⁻³ Torr or less (≦ 10 ⁻² Torr)
After a vacuum of ^-3 Torr), monomer vapor corresponding to the vapor pressure of the monomer at room temperature is supplied so that the vapor enters the graphite layer of K-GIC.

With the start of introduction of the monomer between the graphite layers in the K-GIC, the expansion of the graphite starts very slowly in the c-axis direction, and polymerization of the monomer is started using K as a polymerization initiator. A polymer complex is obtained;
The amount of the monomer introduced into the K-GIC may be determined in consideration of the characteristics of the graphite-polymer composite, etc.
It is in the range of about 1000 times.

The weight ratio of graphite to polymer in the composite is substantially determined by the amount of the monomer introduced into K-GIC, and is approximately K-GIC: polymer = 1;

The properties of the obtained graphite-polymer composite are generally black, resilient, and expanded graphite (when the amount of introduced monomer is small) to graphite-dispersed polymer (based on the amount of introduced monomer) depending on the amount of monomer introduced. (When the amount is large). The inside of the composite has a structure in which a graphite hexagonal mesh plane is cleaved in each layer and a polymer is interposed therebetween.

The graphite-polymer composite is used in an amount of 500 to 100.
By heat-treating at about 0 ° C to decompose and remove the polymer, a new graphite material with low lamination properties in the c-axis direction is obtained while retaining the original graphite material crystallinity in the ab-axis direction. be able to. At this time, the degree of lamination in the c-axis direction can be controlled by adjusting the heat treatment temperature of the composite.

The polymerization mechanism in the present invention is considered to be anionic polymerization by a living polymer in view of the chemical species involved. In fact, it was found that re-contacting the graphite-polymer composite obtained in Example 1 with isoprene vapor increased the weight of the polymer by about 5%.

[0019]

According to the present invention, a novel graphite-polymer composite can be obtained. Such a graphite-polymer composite is useful as a structural material for a micromachine, an insulating material for a microchip, and the like.

Further, the composite is further heat-treated to remove the polymer component, thereby obtaining a novel graphite material in which the state of lamination in the c-axis direction is controlled. Such a graphite material is useful as a functional adsorbent, a molecular sieve material, a catalyst supporting material, and the like.

[0021]

EXAMPLES Examples are shown below to further clarify the features of the present invention.

Example 1 Using a highly oriented pyrolytic graphite (HOPG; manufactured by UCC, USA), a 2-valve method ("Introduction to New Carbon Materials", Realize Inc. (1996), pp. 159-160) KC ₂₄ is synthesized and stored in a closed container, and the pressure in the container is previously set to 10 ⁻³ Torr or less.
(≦ 10 ⁻³ Torr) after the vacuum, temperature = room temperature, isoprene vapor corresponding to the vapor pressure of isoprene at room temperature is introduced,
Reacted. Isoprene is a molecular sieve 4A in advance
, And purified by vacuum distillation.

The graphite-polymer composite obtained 24 hours after the start of the reaction is a black, resilient, expanded graphite-like material, and about 173 times the amount of isoprene based on ₂₄ weights of KC. Occluded.

Table 1 shows the results of elemental analysis of the obtained graphite-polyisoprene composite.

[0025]

[Table 1]

The obtained graphite-polyisoprene composite was washed with water, dried, and subjected to elemental analysis. As a result, no change was observed.

The graphite-polyisoprene composite obtained by the above method is heated from room temperature to 500 ° C. or 100 ° C. at a heating rate of 200 ° C./hr.
After the temperature was raised to 0 ° C., the temperature was maintained at the same temperature for 30 minutes, and then the product cooled in the furnace was subjected to a powder diffraction test using X-rays. FIG. 1 shows the results. In FIG. 1, “RT” indicates the result of the composite powder that was not subjected to the heat treatment.

As is clear from the results shown in FIG. 1, the graphite-polyisoprene composite of the present invention has
No diffraction line attributable to C is observed. This means that the polymerization of isoprene occurs between the graphite layers of KC ₂₄ ,
The graphite hexagonal mesh plane expanded by the formed polymer is no longer crystallized in the c-axis direction.

The peak intensity of graphite in the material heat-treated at 500 ° C. is very low. Further, also in the case of the material heat-treated at 1000 ° C., the peak intensity of the diffraction line is lower than that of KC ₂₄ before composite or graphite as a starting material. As is apparent from these results, by heating the graphite-polyisoprene composite according to the present invention, crystals are sufficiently developed in the ab-axis direction, but the lamination property is low in the c-axis direction. Graphite having a simple structure can be obtained. At this time, it is possible to control the laminability in the c-axis direction by adjusting the heat treatment temperature and time.

Tg of the obtained graphite-polyisoprene composite
FIG. 2 shows the -DTA curve (sample weight = 11.10 mg, heating rate = 200 ° C./hr), and FIG. 3 shows the Tg-DTA curve of polystyrene.

From the results shown in FIGS. 2 and 3, it is clear that polyisoprene is formed in the composite.

Further, the graphite-polymer composite according to the present invention is different from graphite or GIC which has excellent conductivity,
It was confirmed that no conductivity was exhibited.

Example 2 A graphite-polystyrene composite was obtained in the same manner as in Example except that styrene was used as the unsaturated hydrocarbon.

The obtained graphite-polymer composite is black,
It is a resilient, expanded graphite-like material, storing about 217 times the amount of styrene based on ₂₄ weights of KC.

Table 2 shows the results of elemental analysis of the obtained graphite-polystyrene composite.

[0036]

[Table 2]

The obtained graphite-polystyrene composite was washed with water, dried, and subjected to elemental analysis. As a result, no change was observed.

Next, the graphite-polystyrene composite obtained by the above-described method was subjected to an X-ray powder diffraction test. FIG. 4 shows the result. As is clear from the results shown in FIG. 4, in the graphite-polystyrene composite according to the present invention, no diffraction line attributed to graphite or GIC is recognized.

Tg-D of the obtained graphite-polystyrene composite
FIG. 5 shows a TA curve (sample weight: 14.50 mg, heating rate = 200 ° C./hr), and FIG. 6 shows a Tg-DTA curve of polystyrene.

From the results shown in FIGS. 5 and 6, it is clear that polystyrene is formed in the composite.

Example 3 A gaseous 1,3-butadiene (purity of 99.5% or more) packed in a cylinder was used as an unsaturated hydrocarbon, and the butadiene pressure was reduced.
A graphite-polybutadiene composite was obtained in the same manner as in Example 1 except that the pressure was changed to 500 Torr.

The obtained graphite-polymer composite is black,
It is a resilient, expanded graphite-like material that occludes about 153 times the amount of butadiene, based on ₂₄ weights of KC.

Table 3 shows the results of elemental analysis of the obtained graphite-polybutadiene composite.

[0044]

[Table 3]

The obtained graphite-polybutadiene composite was washed with water, dried, and subjected to elemental analysis. As a result, no change was observed.

Next, the graphite-polybutadiene composite obtained by the above method was subjected to a powder diffraction test by X-rays.
FIG. 7 shows the result. As is clear from the results shown in FIG. 7, in the graphite-polybutadiene composite according to the present invention, no diffraction line attributed to graphite or GIC is observed.

Tg of the obtained graphite-polybutadiene composite
FIG. 8 shows a -DTA curve (sample weight = 4.50 mg, heating rate = 200 ° C./hr), and FIG. 9 shows a Tg-DTA curve of polybutadiene.

From the results shown in FIGS. 8 and 9, it is clear that polybutadiene is formed in the composite.

[Brief description of the drawings]

FIG. 1 is a chart showing the results of a powder diffraction test using X-rays of a graphite-polyisoprene composite obtained in Example 1 and a heat-treated product thereof.

FIG. 2 is a Tg-DTA curve for the graphite-polyisoprene complex obtained in Example 1.

FIG. 3 is a Tg-DTA curve for polyisoprene itself.

FIG. 4 is a chart showing the results of performing a powder diffraction test with X-rays on the graphite-polystyrene composite obtained in Example 2.

FIG. 5 is a Tg-DTA curve for the graphite-polystyrene composite obtained in Example 2.

FIG. 6 is a Tg-DTA curve for polystyrene itself.

FIG. 7 is a chart showing the results of performing a powder diffraction test with X-rays on the graphite-polybutadiene composite obtained in Example 3.

FIG. 8 is a Tg-DTA curve for the graphite-polybutadiene composite obtained in Example 3.

FIG. 9 is a Tg-DTA curve for polybutadiene itself.

──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Kazuhiro Fujita 1-81-31 Midorioka, Ikeda-shi, Osaka Prefecture Inside the Osaka Institute of Technology (72) Inventor Yoshihiro Sawada 1-81-31 Midorioka, Ikeda-shi, Osaka No. 58 Institute of Industrial Technology Osaka Institute of Industrial Technology (58) Field surveyed (Int. Cl. ⁶ , DB name) B32B 1/00-35/00 C01B 31/00-31/36

Claims (3)

(57) [Claims] 1. A graphite-polymer composite that holds a polymer between graphite layers of an alkali metal-graphite intercalation compound. 2. A method for producing a graphite-polymer composite, comprising introducing an unsaturated hydrocarbon between the graphite layers of an alkali metal-graphite intercalation compound and polymerizing the unsaturated hydrocarbon using the alkali metal as a catalyst. . 3. An unsaturated hydrocarbon is introduced between the graphite layers of the alkali metal-graphite intercalation compound, and the unsaturated hydrocarbon is polymerized using the alkali metal as a catalyst. A method for producing a graphite material.