JP2012236960A - Resin composition material - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a noble resin composite material in which fine graphite particles is dispersed in an olefin-based resin.SOLUTION: The resin composite material contains: the fine graphite particles including a plate-like graphite particle, an aromatic vinyl copolymer that is adsorbed on the plate-like graphite particle and contains a vinyl aromatic monomer unit represented by formula (1):-(CH-CHX)-(1) (in formula (1), X represents a phenyl group, a naphthyl group, an anthracenyl group or a pyrenyl group, which may have a substituent), and at least one hydrocarbon chain that is bonded to the aromatic vinyl copolymer and selected from the group consisting of alkyl chains, oligoolefin chains and polyolefin chains; and an olefin-based resin.

Description

  The present invention relates to a resin composite material containing graphite particles and an olefin resin.

  Olefin resins are excellent in the balance between price and mechanical properties and are one of the most widely used resins. Conventionally, various fillers are added to such olefin-based resins in order to impart various characteristics, and graphite particles are one of them. For example, in Japanese Patent Application Laid-Open No. 59-96142 (Patent Document 1), a thermoplastic filler such as polypropylene is mixed with a conductive filler such as carbon black or graphite to impart conductivity to the thermoplastic resin, thereby shielding an electromagnetic wave. It is disclosed to improve the performance. However, since graphite particles have a low affinity with olefin resins such as polypropylene, they tend to agglomerate in olefin resins and are difficult to disperse uniformly. Graphite particles have electrical conductivity and mechanical properties that are olefins. It could not be said that it was sufficiently applied to the resin.

  Japanese Patent Laid-Open No. 2003-268245 (Patent Document 2) discloses that layered carbon can be uniformly finely dispersed in a resin by subjecting the layered carbon to a hydrogenation treatment or an alkylation treatment. However, according to the method described in Patent Document 2, even when the alkyl particles are subjected to alkylation treatment using an alkyl zinc compound, the surface of the graphite particles is not alkylated, and the conjugated structure on the surface of the graphite particles is further destroyed. There was a problem that electric conductivity was lowered. In addition, organometallic compounds such as alkyl zinc compounds are unstable and difficult to handle, and are not suitable for industrial production.

JP 59-96142 A JP 2003-268245 A

  The present invention has been made in view of the above-mentioned problems of the prior art, and an object thereof is to provide a novel resin composite material in which fine graphite particles are dispersed in an olefin resin.

  As a result of intensive studies to achieve the above object, the present inventors have found that the fragrance in the fine graphite particles comprising plate-like graphite particles and an aromatic vinyl copolymer adsorbed on the plate-like graphite particles. The platy graphite particles can be easily dispersed in an olefin resin by introducing at least one hydrocarbon chain of an alkyl chain, an oligoolefin chain and a polyolefin chain into an aromatic vinyl copolymer. As a result, the present invention has been completed.

That is, the resin composite material of the present invention has plate-like graphite particles and the following formula (1) adsorbed on the plate-like graphite particles:
_{- (CH 2 -CHX) - (} 1)
(In formula (1), X represents a phenyl group, a naphthyl group, an anthracenyl group, or a pyrenyl group, and these groups may have a substituent.)
And at least one selected from the group consisting of an alkyl chain, an oligoolefin chain, and a polyolefin chain bonded to the aromatic vinyl copolymer. It contains the refined graphite particle | grains provided with the following hydrocarbon chain, and an olefin resin.

  In such a resin composite material, the fine graphite particles are preferably present in a state of being dispersed in the olefin resin. The aromatic vinyl copolymer preferably has a functional group, and the hydrocarbon chain has at least one selected from alkyl compounds, oligoolefins and polyolefins having a site that reacts with the functional group. Are preferably formed by bonding to the functional group.

  The aromatic vinyl copolymer according to the present invention is selected from the group consisting of the vinyl aromatic monomer unit and (meth) acrylic acid, (meth) acrylates, (meth) acrylamides, vinylimidazoles and vinylpyridines. Those having other monomer units derived from at least one selected monomer are preferred. The functional group is preferably an amino group, and the site that reacts with the functional group is preferably at least one selected from the group consisting of a chlorine atom, a carboxyl group, and a carboxylic anhydride group.

  The reason why the fine graphite particles according to the present invention can be easily dispersed in the olefin resin is not necessarily clear, but the present inventors speculate as follows. That is, normal graphite particles are easy to aggregate and the surface thereof is chemically inert, so that it is difficult to disperse them in an olefin resin having a low polarity. On the other hand, in the refined graphite particles according to the present invention, since the aromatic vinyl copolymer is adsorbed on the surface of the refined plate-like graphite particles, the cohesive force between the plate-like graphite particles is reduced. Since the aromatic vinyl copolymer is introduced with at least one hydrocarbon chain of an alkyl chain, an oligoolefin chain and a polyolefin chain, the surface of the fine graphite particles is alkylated. As a result, it is surmised that the fine graphite particles according to the present invention have improved affinity for olefin resins and can be easily dispersed without agglomeration in the olefin resin.

  According to the present invention, a novel resin composite material in which fine graphite particles are dispersed in an olefin resin can be obtained.

2 is an optical micrograph of the PP resin composite material produced in Example 1. FIG. 3 is an optical micrograph of a PP resin composite material produced in Example 2. 4 is an optical micrograph of the PP resin composite material produced in Example 3. 4 is an optical micrograph of a PP resin composite material produced in Example 4. 6 is an optical micrograph of a PP resin composite material produced in Example 5. 6 is an optical micrograph of a PP resin composite material produced in Example 6. 6 is an optical micrograph of a PP resin composite material produced in Example 6. 6 is an optical micrograph of an HDPE resin composite material produced in Example 6. 2 is an optical micrograph of a PP resin composite material produced in Comparative Example 1. It is a graph which shows the relationship between the content at the time of kneading | mixing PP resin composite material, and the content of the fine graphite particle | grains or graphite particle in PP resin composite material. (A) is a photograph of the PP resin composite material produced in Example 7, and (b) is a photograph of the PP resin composite material produced in Comparative Example 3. It is a graph which shows the relationship between content of the refined | miniaturized graphite particle | grains or graphite particle | grains in PP resin composite material, and the storage elastic modulus of PP resin composite material. It is a graph which shows the relationship between the content of the fine graphite particle | grains or graphite particle | grains in PP resin composite material, and the loss elastic modulus of PP resin composite material. It is a graph which shows the temperature dependence of the storage elastic modulus of PP resin composite material produced in Examples 9, 12 and Comparative Example 5, and PP resin material produced in Comparative Example 2.

  Hereinafter, the present invention will be described in detail with reference to preferred embodiments thereof. The resin composite material of the present invention comprises plate-like graphite particles, a specific aromatic vinyl copolymer adsorbed on the plate-like graphite particles, an alkyl chain, an oligoolefin chain and a bond bonded to the aromatic vinyl copolymer. It contains refined graphite particles having at least one hydrocarbon chain of polyolefin chains, and an olefin resin. In such a resin composite material, the fine graphite particles are preferably present in a state dispersed in the olefin resin. As a result, characteristics such as electrical conductivity and thermal conductivity of the graphite particles tend to be sufficiently imparted to the olefin resin.

<Refined graphite particles>
First, the refined graphite particles according to the present invention will be described. The refined graphite particles according to the present invention include plate-like graphite particles, a specific aromatic vinyl copolymer adsorbed on the plate-like graphite particles, and an alkyl chain and oligoolefin bonded to the aromatic vinyl copolymer. And at least one hydrocarbon chain of a chain and a polyolefin chain.

  The plate-like graphite particles constituting the fine graphite particles are not particularly limited, and for example, known graphite having a graphite structure (artificial graphite, natural graphite (for example, flaky graphite, massive graphite, earthy graphite)) is used. What is obtained by grind | pulverizing so that a graphite structure may not be destroyed is mentioned.

  The thickness of such plate-like graphite particles is not particularly limited, but is preferably 0.3 to 1000 nm, more preferably 0.3 to 100 nm, and particularly preferably 1 to 100 nm. Further, the size in the planar direction of the plate-like graphite particles is not particularly limited. For example, the length in the major axis direction (major axis) is preferably 0.1 to 500 μm, more preferably 1 to 500 μm, and the minor axis. The length (minor axis) in the direction is preferably 0.1 to 500 μm, and more preferably 0.3 to 100 μm.

  Moreover, it is preferable that functional groups such as a hydroxyl group, a carboxyl group, and an epoxy group are bonded (more preferably covalently bonded) to the surface of the plate-like graphite particles according to the present invention. The functional group has an affinity with the aromatic vinyl copolymer according to the present invention, and the adsorption amount and adsorption force of the aromatic vinyl copolymer to the plate-like graphite particles are increased, so that the fine graphite particles Tends to be highly dispersible in the olefin resin.

  Such a functional group is 50% or less (more preferably 20% or less, particularly preferably 10% or less) of the total carbon atoms in the vicinity of the surface of the plate-like graphite particles (preferably, a region from the surface to a depth of 10 nm). It is preferable that it is bonded to the carbon atom. When the ratio of the carbon atom to which the functional group is bonded exceeds the upper limit, the plate-like graphite particles tend to have a low affinity with the aromatic vinyl copolymer because the hydrophilicity increases. Moreover, there is no restriction | limiting in particular as a minimum of the ratio of the carbon atom which the functional group has couple | bonded, However 0.01% or more is preferable. The functional group such as a hydroxyl group can be quantified by X-ray photoelectron spectroscopy (XPS), and the amount of the functional group present in a region from the particle surface to a depth of 10 nm can be measured. In addition, when the thickness of the plate-like graphite particles is 10 nm or less, the amount of functional groups present in the entire region of the plate-like graphite particles is measured.

The aromatic vinyl copolymer according to the present invention has the following formula (1):
_{- (CH 2 -CHX) - (} 1)
(In formula (1), X represents a phenyl group, a naphthyl group, an anthracenyl group, or a pyrenyl group, and these groups may have a substituent.)
The vinyl aromatic monomer unit represented by these and other monomer units are contained. The vinyl aromatic monomer unit exhibits adsorptivity to graphite particles, whereby the aromatic vinyl copolymer is adsorbed on the plate-like graphite particles and reduces the cohesive force between the plate-like graphite particles. It becomes possible.

  Moreover, as an aromatic vinyl copolymer concerning this invention, what has a functional group is preferable. This makes it possible to easily introduce at least one hydrocarbon chain among an alkyl chain, an oligoolefin chain, and a polyolefin chain into the aromatic vinyl copolymer. Examples of such a functional group include an amino group, a carboxyl group, a carboxylic acid ester group, a hydroxyl group, an amide group, an imino group, and a glycidyl group, and among these, an amino group is preferable.

  In the aromatic vinyl copolymer having the functional group, the functional group may be present in at least one of the vinyl aromatic monomer unit and the other monomer unit. From the viewpoint that the adsorptivity of the vinyl copolymer is not impaired, the other monomer units are preferably those having the functional group, and from the viewpoint that an alkyl chain, an oligoolefin chain and a polyolefin chain can be easily introduced. More preferably, the other monomer unit is another vinyl monomer unit having the functional group.

  In the aromatic vinyl copolymer according to the present invention, the higher the content of the vinyl aromatic monomer unit, the greater the amount of adsorption to the plate-like graphite particles. The dispersibility in the olefin resin tends to be high. As content of a vinyl aromatic monomer unit, 10-98 mass% is preferable with respect to the whole aromatic vinyl copolymer, 30-98 mass% is more preferable, 50-95 mass% is especially preferable. When the content of the vinyl aromatic monomer unit is less than the lower limit, the amount of adsorption of the aromatic vinyl copolymer to the plate-like graphite particles tends to decrease, and the dispersibility of the fine graphite particles tends to decrease. On the other hand, if the content of the vinyl aromatic monomer unit exceeds the upper limit, an alkyl chain, an oligoolefin chain, and a polyolefin chain are bonded to the aromatic vinyl copolymer when the other monomer unit has a functional group. It becomes difficult to do so, and the affinity for the olefin resin is not imparted to the plate-like graphite particles, and the dispersibility of the fine graphite particles tends to be lowered.

  Examples of the vinyl aromatic monomer unit according to the present invention include a styrene monomer unit, a vinyl naphthalene monomer unit, a vinyl anthracene monomer unit, and a vinyl pyrene monomer unit. Further, these vinyl aromatic monomer units may have a substituent. Examples of such a substituent, that is, a substituent that the group represented by X in the formula (1) may have include an amino group, a carboxyl group, a carboxylic acid ester group, a hydroxyl group, an amide group, and an imino group. Group, glycidyl group, alkoxy group (for example, methoxy group), carbonyl group, imide group, phosphate ester group and the like. Among them, from the viewpoint of improving the dispersibility of the fine graphite particles, An alkoxy group is preferable, a methoxy group is more preferable, and the functional group is preferable from the viewpoint that an alkyl chain, an oligoolefin chain, and a polyolefin chain can be bonded to the vinyl aromatic monomer unit. Examples of the vinyl aromatic monomer unit having such a substituent include an aminostyrene monomer unit, a vinyl benzoate ester monomer unit, a hydroxystyrene monomer unit, a vinylanisole monomer unit, and an acetylstyrene monomer unit. Among these substituted or unsubstituted vinyl aromatic monomer units, from the viewpoint of improving the dispersibility of the fine graphite particles, a styrene monomer unit, a vinyl naphthalene monomer unit, and a vinyl anisole monomer unit are preferable, and an alkyl chain and an oligoolefin. From the viewpoint that the chain and the polyolefin chain can be bonded, an aminostyrene monomer unit is preferable.

  Other monomer units according to the present invention are not particularly limited, but at least one selected from the group consisting of (meth) acrylic acid, (meth) acrylates, (meth) acrylamides, vinylimidazoles and vinylpyridines. Functional group-containing vinyl monomer units derived from vinyl monomers having various functional groups are preferred. By using an aromatic vinyl copolymer containing other vinyl monomer units having such a functional group, an alkyl chain, an oligoolefin chain, and a polyolefin chain can be easily introduced into the aromatic vinyl copolymer. In addition, the obtained fine graphite particles have improved affinity with the olefin resin, and can be easily dispersed in the olefin resin.

  Examples of the other vinyl monomer having an amino group include aminoalkyl (meth) acrylates, vinyl pyridines (for example, 2-vinyl pyridine, 4-vinyl pyridine), vinyl imidazoles (for example, 1-vinyl imidazole), and the like. It is done. Examples of the other vinyl monomer having a carboxyl group include (meth) acrylic acid. As the other vinyl monomer having the carboxylic acid ester group, alkyl (meth) acrylate, as the other vinyl monomer having the hydroxyl group, hydroxyalkyl (meth) acrylate, as the other vinyl monomer having the amide group, (Meth) acrylamide, N-alkyl (meth) acrylamide, N, N-dialkyl (meth) acrylamide and the like can be mentioned.

  Among other vinyl monomers having such a functional group, from the viewpoint that an alkyl chain, an oligoolefin chain and a polyolefin chain can be easily introduced into an aromatic vinyl copolymer, hydroxyalkyl (meth) acrylate, Aminoalkyl (meth) acrylate, N, N-dialkyl (meth) acrylamide, 2-vinylpyridine and 4-vinylpyridine are preferable, and aminoalkyl (meth) acrylate, 2-vinylpyridine and 4-vinylpyridine are more preferable. -Vinylpyridine is particularly preferred.

  In the fine graphite particles according to the present invention, the number average molecular weight of the aromatic vinyl copolymer is not particularly limited, but is preferably 1,000 to 1,000,000, and more preferably 5,000 to 100,000. If the number average molecular weight of the aromatic vinyl copolymer is less than the lower limit, the adsorptive capacity to graphite particles tends to be reduced. On the other hand, if the upper limit is exceeded, the solubility in a solvent is reduced or the viscosity is remarkably increased. It tends to rise and become difficult to handle. The number average molecular weight of the aromatic vinyl copolymer was measured by gel permeation chromatography (column: Shodex GPC K-805L and Shodex GPC K-800RL (both manufactured by Showa Denko KK), eluent: chloroform). It is a value converted with standard polystyrene.

  In the refined graphite particles according to the present invention, a random copolymer or a block copolymer may be used as the aromatic vinyl copolymer, but the dispersibility of the refined graphite particles is improved. From the viewpoint of achieving this, it is preferable to use a block copolymer.

In fine graphite particles according to the present invention, the content of the aromatic vinyl copolymer, preferably ¹⁰ -7 ^{to 10 -1} parts by weight with respect to the plate-like graphite particles 100 parts by weight, ^{10 -5 10-2} mass parts is more preferable. When the content of the aromatic vinyl copolymer is less than the lower limit, because the adsorption of the aromatic vinyl copolymer to the plate-like graphite particles is insufficient, the dispersibility of the fine graphite particles tends to decrease, On the other hand, when the upper limit is exceeded, there is a tendency that an aromatic vinyl copolymer that is not directly adsorbed on the plate-like graphite particles exists.

  The alkyl chain, oligoolefin chain and polyolefin chain according to the present invention are those bonded to the aromatic vinyl copolymer. Thereby, the surface of the refined graphite particles according to the present invention is alkylated, exhibits affinity for a low-polarity olefin resin, and can be easily dispersed in the olefin resin. Further, such an alkyl chain, oligoolefin chain and polyolefin chain are preferably bonded to a side chain of the aromatic vinyl copolymer. This tends to further improve the affinity of the fine graphite particles for the olefin resin.

  In such fine graphite particles, the alkyl chain, oligoolefin chain, and polyolefin chain include an aromatic vinyl copolymer having the functional group and a site that reacts with the functional group (hereinafter referred to as “reactive site”). The alkyl compound, oligoolefin and polyolefin react with each other, and the reactive site of the alkyl compound, oligoolefin and polyolefin is bonded to the functional group of the aromatic vinyl copolymer. It is preferable.

  Such reactive sites include halogen atoms (such as chlorine, bromine, and iodine atoms), carboxyl groups, carboxylic anhydride groups (such as maleic anhydride groups), sulfonic acid groups, aldehyde groups, and glycidyl groups. From the viewpoint of high reactivity with the functional group, a halogen atom, a carboxyl group, and a carboxylic anhydride group are preferable, a halogen atom is more preferable, and a chlorine atom is further preferable. Further, the combination of the functional group and the reactive site is preferably a combination of an amino group and a halogen atom, or a combination of an amino group and a carboxyl group or a carboxylic acid anhydride group from the viewpoint of increasing the reactivity of each other. A combination of an amino group and a chlorine atom, a combination of an amino group and a maleic anhydride group is more preferable, and a combination of an amino group and a chlorine atom is particularly preferable.

  The alkyl compound, oligoolefin and polyolefin having such a reactive site are not particularly limited, but the alkyl compound, oligoolefin and polyolefin having the functional group at the molecular terminal (hereinafter referred to as “terminal functional group-containing”, respectively). Alkyl compounds "," terminal functional group-containing oligoolefins "and" terminal functional group-containing polyolefins "are preferred. Such a terminal functional group-containing alkyl compound, a terminal functional group-containing oligoolefin, and a terminal functional group-containing polyolefin easily react with the aromatic vinyl copolymer having the functional group, and the aromatic vinyl copolymer can be easily alkylated. Chains, oligoolefin chains and polyolefin chains can be introduced.

  As alkyl compounds, oligoolefins and polyolefins having a reactive site, specifically, chlorinated products, brominated products, hydroxyl group-containing products, maleic acid modified products, (meth) acrylic acid modified products of alkyl compounds, oligoolefins and polyolefins Among them, terminal chlorinated products and terminal hydroxyl group-containing products are preferable, and terminal chlorinated products are more preferable. Although there is no restriction | limiting in particular as a kind of oligoolefin and polyolefin, From a viewpoint that an oligoolefin chain and a polyolefin chain are easy to be introduced, an ethylene oligomer, polyethylene, a propylene oligomer, a polypropylene, an ethylene-propylene copolymer (oligomer and polymer) are used. preferable.

  Although there is no restriction | limiting in particular as a number average molecular weight of polyolefin which has such a reactive site, 100-1 million are preferable and 1000-10,000 are more preferable. When the number average molecular weight of the polyolefin is less than the lower limit, the introduced polyolefin chain is short, and the affinity of the fine graphite particles for the olefin resin tends not to be sufficiently improved. It is difficult to bond to an aromatic vinyl copolymer, and it is difficult to introduce a polyolefin chain. Similarly, the molecular weight of the alkyl compound having a reactive site is not particularly limited, but is preferably 70 to 500, and the number average molecular weight of the oligoolefin having the reactive site is not particularly limited. ~ 5000 is preferred.

  As described above, the fine graphite particles according to the present invention have a high affinity with the olefin resin, and in the resin composite material of the present invention, they are easily dispersed in the olefin resin. In the case of producing the resin composite material of the present invention by mixing finely divided graphite particles according to the present invention and an olefin resin in a solvent, for example, as described later, the dispersibility in the solvent is excellent. The fine graphite particles can be easily dispersed in the solvent, and the resin composite material of the present invention in which the fine graphite particles are uniformly dispersed in the olefin resin can be easily obtained.

  Next, the manufacturing method of the refined graphite particle concerning this invention is demonstrated. Fine graphite particles according to the present invention are obtained by mixing raw material graphite particles, an aromatic vinyl copolymer containing a vinyl aromatic monomer unit represented by the above formula (1), a hydrogen peroxide, and a solvent, The obtained mixture is pulverized and further introduced with at least one hydrocarbon chain of an alkyl chain, an oligoolefin chain and a polyolefin chain into the aromatic vinyl copolymer in the refined graphite particles. Can be manufactured by.

  As the graphite particles used as raw materials when producing the fine graphite particles according to the present invention (hereinafter referred to as “raw graphite particles”), known graphites having a graphite structure (artificial graphite, natural graphite (for example, scaly) Graphite, lump graphite, earthy graphite)), and among them, those that become plate-like graphite particles having a thickness in the above range by pulverization are preferable. Although there is no restriction | limiting in particular as a particle diameter of such a raw material graphite particle, 0.01-5 mm is preferable and 0.1-1 mm is more preferable.

  Moreover, it is preferable that functional groups such as a hydroxyl group, a carboxyl group, and an epoxy group are bonded (preferably covalently bonded) to the surface of the plate-like graphite particles constituting the raw graphite particles. The functional group has an affinity for the aromatic vinyl copolymer, and the adsorption amount of the aromatic vinyl copolymer to the plate-like graphite particles increases, so that the alkyl chain, oligoolefin chain, and polyolefin chain Therefore, the resulting fine graphite particles tend to have improved affinity for olefin resins and higher dispersibility.

  Such a functional group is 50% or less (more preferably 20% or less, particularly preferably 10% or less) of the total carbon atoms in the vicinity of the surface of the plate-like graphite particles (preferably, a region from the surface to a depth of 10 nm). It is preferable that it is bonded to the carbon atom. When the ratio of the carbon atom to which the functional group is bonded exceeds the upper limit, the plate-like graphite particles tend to have a low affinity with the aromatic vinyl copolymer because the hydrophilicity increases. Moreover, there is no restriction | limiting in particular as a minimum of the ratio of the carbon atom which the functional group has couple | bonded, However 0.01% or more is preferable.

  Examples of the hydrogen peroxide used in the production of the fine graphite particles include compounds having a carbonyl group (for example, urea, carboxylic acid (benzoic acid, salicylic acid, etc.), ketone (acetone, methyl ethyl ketone, etc.), carboxylic acid ester. (Methyl benzoate, ethyl salicylate, etc.)) and hydrogen peroxide complexes; quaternary ammonium salts, potassium fluoride, rubidium carbonate, phosphoric acid, uric acid and other compounds with hydrogen peroxide coordinated . Such hydrogen peroxide acts as an oxidant when producing fine graphite particles according to the present invention, and facilitates exfoliation between carbon layers without destroying the graphite structure of the raw graphite particles. is there. That is, hydrogen peroxide enters between the carbon layers to oxidize the surface of the layer, and proceeds with cleavage. At the same time, the aromatic vinyl copolymer penetrates into the cleaved carbon layer and stabilizes the cleavage surface. Promoted. As a result, the aromatic vinyl copolymer is adsorbed on the surface of the plate-like graphite particles, and the alkyl chain, oligoolefin chain, and polyolefin chain are bonded to the aromatic vinyl copolymer, whereby fine graphite particles are formed. It can be easily dispersed in the olefin resin.

  The solvent used for producing the fine graphite particles is not particularly limited, but dimethylformamide (DMF), chloroform, dichloromethane, chlorobenzene, dichlorobenzene, N-methylpyrrolidone (NMP), hexane, toluene, dioxane, propanol, γ-picoline, acetonitrile, dimethyl sulfoxide (DMSO), and dimethylacetamide (DMAC) are preferable, and dimethylformamide (DMF), chloroform, dichloromethane, chlorobenzene, dichlorobenzene, N-methylpyrrolidone (NMP), hexane, and toluene are more preferable.

  When producing the fine graphite particles according to the present invention, first, the raw graphite particles, the aromatic vinyl copolymer, the hydrogenated product, and the solvent are mixed (mixing step). The mixing amount of the raw graphite particles is preferably 0.1 to 500 g / L, more preferably 10 to 200 g / L, per liter of the solvent. When the mixing amount of the raw material graphite particles is less than the lower limit, the consumption of the solvent tends to increase, which tends to be economically disadvantageous. On the other hand, when the upper limit is exceeded, the viscosity of the liquid increases and handling becomes difficult. There is a tendency.

  Moreover, as a mixing amount of the said aromatic vinyl copolymer, 0.1-1000 mass parts is preferable with respect to 100 mass parts of said raw material graphite particles, and 0.1-200 mass parts is more preferable. If the mixing amount of the aromatic vinyl copolymer is less than the lower limit, the dispersibility of the obtained fine graphite particles in the olefin resin tends to be lowered. On the other hand, if the upper limit is exceeded, the aromatic vinyl copolymer weight is reduced. The coalescence does not dissolve in the solvent, and the viscosity of the liquid tends to increase, making it difficult to handle.

  Further, the mixing amount of the hydrogen peroxide is preferably 0.1 to 500 parts by mass, more preferably 1 to 100 parts by mass with respect to 100 parts by mass of the raw graphite particles. When the mixing amount of the hydrogen peroxide is less than the lower limit, the dispersibility of the obtained fine graphite particles tends to be lowered. On the other hand, when the upper limit is exceeded, the raw graphite particles are excessively oxidized and obtained. There is a tendency for the conductivity of the fine graphite particles to decrease.

  Next, the mixture obtained in the mixing step is pulverized to pulverize the raw graphite particles into plate-like graphite particles (pulverization step). Thereby, the refined graphite particles in which the aromatic vinyl copolymer is adsorbed on the surface of the generated plate-like graphite particles are obtained.

  Examples of the pulverization treatment according to the present invention include ultrasonic treatment (oscillation frequency is preferably 15 to 400 kHz, output is preferably 500 W or less), treatment with a ball mill, wet pulverization, explosion, mechanical pulverization, and the like. This makes it possible to obtain plate-like graphite particles by pulverizing the raw graphite particles without destroying the graphite structure of the raw graphite particles. Moreover, there is no restriction | limiting in particular as temperature at the time of a grinding | pulverization process, For example, -20-100 degreeC is mentioned. Moreover, there is no restriction | limiting in particular also about pulverization processing time, For example, 0.01 to 50 hours are mentioned.

  The fine graphite particles thus obtained are in a state of being dispersed in a solvent, and can be recovered by removing the solvent by filtration or centrifugation.

  Next, the refined graphite particles obtained in the pulverization step are mixed with at least one of alkyl compounds, oligoolefins and polyolefins having the reactive site, and the aromatics in the refined graphite particles are mixed. At least one hydrocarbon chain of an alkyl chain, an oligoolefin chain and a polyolefin chain is introduced into the vinyl copolymer (hydrocarbon chain introduction step). In this case, the aromatic vinyl copolymer needs to have a functional group, and the functional group and the reactive site are bonded to the aromatic vinyl copolymer to form an alkyl chain, an oligoolefin chain. And at least one hydrocarbon chain of the polyolefin chains is introduced.

  In this hydrocarbon chain introduction step, the refined graphite particles obtained in the pulverization step, at least one of alkyl compounds, oligoolefins and polyolefins having the reactive site, and a solvent are mixed, The aromatic vinyl copolymer having a functional group is reacted with at least one of an alkyl compound, an oligoolefin, and a polyolefin having a reactive site by heating the obtained mixture as necessary. There is no restriction | limiting in particular as a solvent, The solvent illustrated above can be used. The reaction temperature is preferably −10 to 150 ° C., and the reaction time is preferably 0.1 to 10 hours.

  The mixing amount of the fine graphite particles in the hydrocarbon chain introduction step is preferably 1 to 200 g / L, more preferably 1 to 50 g / L, per 1 L of the solvent. When the mixing amount of the fine graphite particles is less than the lower limit, the consumption of the solvent tends to increase, which tends to be economically disadvantageous.On the other hand, when the upper limit is exceeded, the viscosity of the liquid increases and handling is difficult. Tend to be.

  Further, the mixing amount of the alkyl compound, oligoolefin and polyolefin having the reactive site is preferably 0.001 to 500 parts by mass, more preferably 10 to 500 parts by mass with respect to 100 parts by mass of the fine graphite particles. preferable. When the mixing amount of the alkyl compound, oligoolefin and polyolefin is less than the lower limit, the introduction amount of the alkyl chain, oligoolefin chain and polyolefin chain is small, and the dispersibility of the fine graphite particles to the olefin resin does not sufficiently improve On the other hand, when the above upper limit is exceeded, the viscosity of the liquid tends to increase and handling tends to be difficult.

  Thus, the refined graphite particles according to the present invention in which the alkyl chain, the oligoolefin chain and the polyolefin chain are introduced are in a state of being dispersed in the solvent, and are recovered by removing the solvent by filtration or centrifugation. be able to.

<Olefin resin>
In the present invention, the olefin resin is not particularly limited, and low density polyethylene (LDPE), high density polyethylene (HDPE), polypropylene, ethylene-propylene copolymer, ethylene-acrylic copolymer, propylene-acrylic copolymer. Known olefin resins such as polyisoprene, neoprene, polybutadiene, and alicyclic olefin polymers can be used.

  Although there is no restriction | limiting in particular as a weight average molecular weight of such an olefin resin, 5,000-1 million are preferable. When the weight average molecular weight of the olefin resin is less than the lower limit, the mechanical strength of the resin composite material tends to decrease. On the other hand, when the upper limit is exceeded, the viscosity becomes too high and the resin composite material is molded. Tend to be difficult.

  The melt flow index of the olefin resin is not particularly limited, but preferably 1 to 100 g / min (190 ° C. (polyethylene) or 230 ° C. (polypropylene), 2.16 kg load). If the melt flow index of the olefin resin is less than the lower limit, the fluidity is low, and it tends to be difficult to mold the resin composite material. On the other hand, if the upper limit is exceeded, the fluidity becomes too high, and the resin It tends to be difficult to stably mold the composite material.

<Resin composite material>
The resin composite material of the present invention contains the fine graphite particles and the olefin resin. Thus, by including the fine graphite particles according to the present invention, the olefin resin is imparted with electrical conductivity, thermal conductivity, high elastic modulus, high strength, slidability, and low linear expansion. Is possible.

  In such a resin composite material, the content of the fine graphite particles is not particularly limited, but is preferably 0.1 to 80% by mass and more preferably 1 to 50% by mass with respect to the entire resin composite material. 1 to 30% by mass is particularly preferable. When the content of fine graphite particles is less than the lower limit, the electrical conductivity and thermal conductivity of the resin composite material tend to decrease, and when the content exceeds the upper limit, it is difficult to mold the resin composite material. Tend to be.

  Such a resin composite material of the present invention can be produced, for example, by mixing fine graphite particles according to the present invention and the olefin resin at a predetermined ratio. At this time, they may be kneaded (preferably melt-kneaded) or mixed in a solvent. There is no restriction | limiting in particular as said solvent, What was illustrated as a solvent used when manufacturing the refined graphite particle concerning this invention can be used.

  When the fine graphite particles and the olefin resin are mixed in a solvent, the olefin resin dissolves in the solvent and becomes uniform, and the fine graphite particles are also highly dispersed in the solvent. It becomes easy to mix and an advanced and uniform dispersion can be easily obtained. Moreover, the uniformity tends to be further improved by subjecting the obtained dispersion to ultrasonic treatment. Then, by removing the solvent from the dispersion thus obtained, a resin composite material in which fine graphite particles are highly dispersed in the olefin resin can be obtained.

EXAMPLES Hereinafter, although this invention is demonstrated more concretely based on an Example and a comparative example, this invention is not limited to a following example. The number average molecular weight (Mn) of the aromatic vinyl copolymer was measured using gel permeation chromatography (“Shodex GPC101” manufactured by Showa Denko KK) under the following conditions.
<Measurement conditions for aromatic vinyl copolymer>
Column: Shodex GPC K-805L and Shodex GPC K-800RL (both manufactured by Showa Denko KK)
・ Eluent: Chloroform ・ Measurement temperature: 25 ° C.
Sample concentration: 0.1 mg / ml
・ Detection means: RI
In addition, the number average molecular weight (Mn) of the aromatic vinyl copolymer showed the value converted with standard polystyrene.

Example 1
<Preparation of fine graphite particles>
18 g of styrene (ST), 2 g of 2-vinylpyridine (2VP), 50 mg of azobisisobutyronitrile and 100 ml of toluene were mixed, and a polymerization reaction was performed at 85 ° C. for 6 hours in a nitrogen atmosphere. After allowing to cool, the mixture was purified by reprecipitation using chloroform-hexane and dried in vacuo to obtain 3.3 g of ST-2VP (9: 1) random copolymer (Mn = 25000).

  20 mg of graphite particles (“EXP-P” manufactured by Nippon Graphite Industry Co., Ltd., particle size 100 to 600 μm), 80 mg of urea-hydrogen peroxide inclusion complex, 20 mg of the ST-2VP (9: 1) random copolymer and N , N-dimethylformamide (DMF) 2 ml was mixed and subjected to ultrasonic treatment (output: 250 W) at room temperature for 5 hours to obtain a graphite particle dispersion. The graphite particle dispersion was allowed to stand for 24 hours and then visually observed. As a result, the graphite particles did not settle, and the obtained dispersion was excellent in dispersion stability. Further, the obtained graphite particle dispersion was filtered, the filter cake was washed with DMF, and then vacuum dried to recover fine graphite particles. When the refined graphite particles were observed with a scanning electron microscope (SEM), they were refined into a plate shape having a length of 1 to 20 μm, a width of 1 to 20 μm, and a thickness of 10 to 50 nm. confirmed.

<Alkylation of fine graphite particles>
Terminal hydroxyl group-containing polyolefin (Idemitsu Kosan Co., Ltd. “Epol (R)”) 4.59 g, triphenylphosphine 1.1 g and carbon tetrachloride 40 ml are mixed and heated in a nitrogen atmosphere at 80 ° C. with stirring for 12 hours. The mixture was refluxed to synthesize terminal chlorinated polyolefin. After evaporating the solution after heating to reflux, the terminal chlorinated polyolefin was extracted with hexane. Then, it refine | purified with silica gel chromatography (hexane solvent), and obtained 1.5-g terminal chlorinated polyolefin (Mn = 2000 (catalog value)).

  Next, 20 mg of the terminal chlorinated polyolefin, 10 mg of the fine graphite particles, and 1 ml of toluene were mixed and stirred at 100 ° C. for 6 hours in a nitrogen atmosphere. The obtained dispersion was filtered, and the filter cake was washed with toluene to obtain fine graphite particles treated with terminal chlorinated polyolefin.

<Production of resin composite material>
0.2 g of refined graphite particles treated with the terminal chlorinated polyolefin and 20 g of isotactic polypropylene (PP, manufactured by Aldrich, weight average molecular weight 190,000) are used at 190 ° C. for 5 minutes using a kneader (minilab). Kneading was performed to obtain a PP resin composite material.

  Further, 0.2 g of fine graphite particles treated with the terminal chlorinated polyolefin and 20 g of high density polyethylene (HDPE, manufactured by Aldrich, melt flow index 12 g / min (190 ° C., 2.16 kg load)) (Minilab) was kneaded at 190 ° C. for 5 minutes to obtain an HDPE resin composite material.

(Example 2)
Instead of 2-vinylpyridine, 0.2 g of 2-dimethylaminoethyl methacrylate (DMAMA) was used, the amount of styrene (ST) was 1.8 g, the amount of azobisisobutyronitrile was 8 mg, and the amount of toluene was 10 ml. Except having changed, it carried out similarly to Example 1, and obtained 0.61 g of ST-DMAMA (9: 1) random copolymer (Mn = 32000).

  Instead of the ST-2VP (9: 1) random copolymer, 0.1 g of this ST-DMAMA (9: 1) random copolymer was used, the amount of graphite particles was 1 g, and urea-hydrogen peroxide inclusion was made. A graphite particle dispersion was obtained in the same manner as in Example 1 except that the amount of the complex was changed to 1 g and the amount of DMF was changed to 50 ml. The graphite particle dispersion was allowed to stand for 24 hours and then visually observed. As a result, the graphite particles did not settle, and the obtained dispersion was excellent in dispersion stability.

  The obtained graphite particle dispersion was filtered, the filter cake was washed with DMF, and then vacuum dried to recover fine graphite particles. When the refined graphite particles were observed with a scanning electron microscope (SEM), they were refined into a plate shape having a length of 1 to 20 μm, a width of 1 to 20 μm, and a thickness of 10 to 50 nm. confirmed.

  Except for using 10 mg of the refined graphite particles, refined graphite particles treated with terminal chlorinated polyolefin were prepared in the same manner as in Example 1, and PP resin composite material and HDPE resin composite material were further produced.

(Example 3)
In the same manner as in Example 2, except that 0.2 g of 4-vinylpyridine (4VP) was used instead of 2-dimethylaminoethyl methacrylate and the amount of toluene was changed to 7.5 ml, 0.73 g of ST-4VP (9 : 1) A random copolymer (Mn = 18000) was obtained.

  A graphite particle dispersion was prepared in the same manner as in Example 1 except that 0.1 g of this ST-4VP (9: 1) random copolymer was used instead of the ST-2VP (9: 1) random copolymer. Obtained. The graphite particle dispersion was allowed to stand for 24 hours and then visually observed. As a result, the graphite particles did not settle, and the obtained dispersion was excellent in dispersion stability.

  The obtained graphite particle dispersion was filtered, the filter cake was washed with DMF, and then vacuum dried to recover fine graphite particles. When the refined graphite particles were observed with a scanning electron microscope (SEM), they were refined into a plate shape having a length of 1 to 20 μm, a width of 1 to 20 μm, and a thickness of 10 to 50 nm. confirmed.

  Except for using 10 mg of the refined graphite particles, refined graphite particles treated with terminal chlorinated polyolefin were prepared in the same manner as in Example 1, and PP resin composite material and HDPE resin composite material were further produced.

Example 4
A refined graphite particle treated with chlorinated polypropylene was prepared in the same manner as in Example 1 except that 20 mg of chlorinated polypropylene (manufactured by Aldrich, Mn = 100000) was used instead of terminal chlorinated polyolefin, PP resin composite material and HDPE resin composite material were prepared.

(Example 5)
Maleic anhydride modified in the same manner as in Example 1 except that 20 mg of maleic anhydride-modified polypropylene (“LICOCENE MA (R)” manufactured by Clariant, viscosity (140 ° C.) = 300 mPa · s) was used instead of terminal chlorinated polyolefin. Fine graphite particles treated with acid-modified polypropylene were prepared, and PP resin composite material and HDPE resin composite material were further produced.

(Example 6)
12.5 g of graphite particles (“EXP-P” manufactured by Nippon Graphite Industries Co., Ltd., particle diameter 100 to 600 μm), 12.5 g of urea-hydrogen peroxide inclusion complex, ST-2VP prepared in the same manner as in Example 1. (9: 1) 1.25 g of random copolymer and 500 ml of DMF are mixed and wetted 10 times under the conditions of room temperature and cylinder pressure of 200 MPa using a wet atomizer (“Starburst Lab” manufactured by Sugino Machine Co., Ltd.). A pulverization process was performed to obtain a graphite particle dispersion. The graphite particle dispersion was allowed to stand for 24 hours and then visually observed. As a result, the graphite particles did not settle, and the obtained dispersion was excellent in dispersion stability.

  The obtained graphite particle dispersion was filtered, the filter cake was washed with DMF, and then vacuum dried to recover fine graphite particles. When the refined graphite particles were observed with a scanning electron microscope (SEM), they were refined into a plate shape having a length of 1 to 20 μm, a width of 1 to 20 μm, and a thickness of 10 to 50 nm. confirmed.

  Except for using 10 mg of the refined graphite particles, refined graphite particles treated with terminal chlorinated polyolefin were prepared in the same manner as in Example 1, and PP resin composite material and HDPE resin composite material were further produced.

(Comparative Example 1)
Example except that 4 g of N-phenylmaleimide (PM) was used instead of 2-vinylpyridine, the amount of styrene (ST) was changed to 36 g, the amount of azobisisobutyronitrile was changed to 100 mg, and the amount of toluene was changed to 50 ml. In the same manner as in Example 1, 25.6 g of ST-PM (9: 1) random copolymer (Mn = 37000) was obtained.

  Instead of the ST-2VP (9: 1) random copolymer, 0.7 g of this ST-PM (9: 1) random copolymer was used, the amount of graphite particles was 7 g, and urea-hydrogen peroxide was included. A graphite particle dispersion was obtained in the same manner as in Example 1 except that the amount of the complex was changed to 7 g and the amount of DMF was changed to 300 ml. The graphite particle dispersion was allowed to stand for 24 hours and then visually observed. As a result, the graphite particles did not settle, and the obtained dispersion was excellent in dispersion stability.

  The obtained graphite particle dispersion was filtered, the filter cake was washed with DMF, and then vacuum dried to recover fine graphite particles. When the refined graphite particles were observed with a scanning electron microscope (SEM), they were refined into a plate shape having a length of 1 to 20 μm, a width of 1 to 20 μm, and a thickness of 10 to 50 nm. confirmed.

  Except for using 10 mg of the refined graphite particles, refined graphite particles treated with terminal chlorinated polyolefin were prepared in the same manner as in Example 1, and PP resin composite material and HDPE resin composite material were further produced.

<Observation with an optical microscope>
The PP resin composite material and HDPE resin composite material obtained in Examples 1 to 6 and Comparative Example 1 were hot pressed at 190 ° C. and 40 kg / cm ² to produce a thin film having a thickness of 0.5 mm. This thin film was observed with an optical microscope. 1 to 6 and FIG. 8 show optical micrographs of the PP resin composite materials obtained in Examples 1 to 6 and Comparative Example 1, and FIG. 7 shows the HDPE resin composite material obtained in Example 6. An optical micrograph is shown. Further, based on these photographs, the dispersibility of the fine graphite particles in the PP resin composite material and the HDPE resin composite material was evaluated. The results are shown in Table 1.

  As is apparent from the results shown in Table 1 and FIGS. 1 to 8, when fine graphite particles including an aromatic vinyl copolymer having an amino group are treated with a polyolefin having a reactive site (Examples 1 to 6). ), It was confirmed that the fine graphite particles can be easily dispersed in the olefin resin. This is presumably because polyolefin chains were introduced into the fine graphite particles due to the reaction between the amino group and the reactive site, and the affinity of the fine graphite particles for the olefin resin was increased.

  On the other hand, when the fine graphite particles having an aromatic vinyl copolymer having no amino group are treated with a polyolefin having a reactive site (Comparative Example 1), the fine graphite particles are aggregated in the olefin resin. It was difficult to disperse. This is because, in Comparative Example 1, the aromatic vinyl copolymer in the fine graphite particles has no functional group such as an amino group, and the reaction with the polyolefin having a reactive site does not proceed. This is probably because the polyolefin chain was not bonded to the vinyl copolymer, and the affinity for the olefin resin was not given to the fine graphite particles.

  In addition, when the fine graphite particles provided with an aromatic vinyl copolymer containing 2VP units are treated with terminal chlorinated polyolefin (Example 1 and Example 6), aromatics containing DMAMA units or 4VP units are used. When the refined graphite particles comprising a vinyl copolymer are treated with terminal chlorinated polyolefin (Examples 2-3), the refined graphite particles comprising an aromatic vinyl copolymer containing 2VP units are chlorinated polypropylene or anhydrous. It was found that the refined graphite particles can be more uniformly and highly dispersed in the olefin resin as compared with the case of treatment with maleic acid-modified polypropylene (Examples 4 to 5). This is because the 2VP unit is more reactive with the terminal chlorinated polyolefin than the DMAMA unit or 4VP unit, or the terminal chlorinated polyolefin having a functional group at the molecular end has a functional group inside the molecule. Compared to polypropylene and maleic anhydride-modified polypropylene, the reactivity with 2VP units is high and the polyolefin chain is easily introduced. Therefore, it is assumed that the three-dimensional polar group is effectively shielded by the polyolefin chain. .

(Example 7)
In the same manner as in Example 1, the fine graphite particles treated with the terminal chlorinated polyolefin were pulverized with a dry pulverizer. 5 parts by mass of fine graphite particles treated with the terminal chlorinated polyolefin and 95 parts by mass of isotactic polypropylene (PP, manufactured by Aldrich, weight average molecular weight 190,000) were mixed to prepare a PP resin composite material.

The PP resin composite material whose volume calculated from the specific gravity was 80 ml was kneaded for 5 minutes at 190 ° C. and 100 rpm using a lab plast mill (“18B-200” manufactured by Toyo Seiki Seisakusho Co., Ltd.). The torque during kneading is shown in FIG. The obtained kneaded material was taken out and hot pressed at 190 ° C. and 40 kg / cm ² to prepare a test piece having a length of 30 mm, a width of 5 mm, and a thickness of 0.5 mm.

  A photograph of the obtained test piece is shown in FIG. Moreover, the elastic modulus of this test piece was measured using a viscoelastic spectrometer ("DVA-220" manufactured by IT Measurement Control Co., Ltd.). The storage elastic modulus, loss elastic modulus, and loss tangent at 40 ° C. are shown in Table 2 and FIGS.

(Example 8)
A PP resin composite material was prepared in the same manner as in Example 7 except that the amount of fine graphite particles treated with terminal chlorinated polyolefin was changed to 10 parts by mass and the amount of the isotactic polypropylene was changed to 90 parts by mass. A test piece was prepared. The torque during kneading is shown in FIG. The elastic modulus of the obtained test piece was measured in the same manner as in Example 7. The storage elastic modulus, loss elastic modulus, and loss tangent at 40 ° C. are shown in Table 2 and FIGS.

Example 9
A PP resin composite material was prepared in the same manner as in Example 7 except that the amount of fine graphite particles treated with terminal chlorinated polyolefin was changed to 20 parts by mass and the amount of the isotactic polypropylene was changed to 80 parts by mass. A test piece was prepared. The torque during kneading is shown in FIG. The elastic modulus of the obtained test piece was measured in the same manner as in Example 7. The storage elastic modulus, loss elastic modulus, and loss tangent at 40 ° C. are shown in Table 2 and FIGS. Moreover, the temperature dependence of the storage elastic modulus is shown in FIG.

(Example 10)
Example 7 except that refined graphite particles treated with terminal chlorinated polyolefin as in Example 6 were used instead of refined graphite particles treated with terminal chlorinated polyolefin as in Example 1. A PP resin composite material was prepared in the same manner as described above to prepare a test piece. The torque during kneading is shown in FIG. The elastic modulus of the obtained test piece was measured in the same manner as in Example 7. The storage elastic modulus, loss elastic modulus, and loss tangent at 40 ° C. are shown in Table 2 and FIGS.

(Example 11)
A PP resin composite material was prepared in the same manner as in Example 10 except that the amount of fine graphite particles treated with terminal chlorinated polyolefin was changed to 10 parts by mass, and the amount of the isotactic polypropylene was changed to 90 parts by mass. A test piece was prepared. The torque during kneading is shown in FIG. The elastic modulus of the obtained test piece was measured in the same manner as in Example 7. The storage elastic modulus, loss elastic modulus, and loss tangent at 40 ° C. are shown in Table 2 and FIGS.

(Example 12)
A PP resin composite material was prepared in the same manner as in Example 10 except that the amount of fine graphite particles treated with terminal chlorinated polyolefin was changed to 20 parts by mass and the amount of the isotactic polypropylene was changed to 80 parts by mass. A test piece was prepared. The torque during kneading is shown in FIG. The elastic modulus of the obtained test piece was measured in the same manner as in Example 7. The storage elastic modulus, loss elastic modulus, and loss tangent at 40 ° C. are shown in Table 2 and FIGS. Moreover, the temperature dependence of the storage elastic modulus is shown in FIG.

(Comparative Example 2)
A PP resin material was prepared in the same manner as in Example 7 except that fine graphite particles treated with terminal chlorinated polyolefin were not mixed, and a test piece was prepared. The torque during kneading is shown in FIG. The elastic modulus of the obtained test piece was measured in the same manner as in Example 7. The storage elastic modulus, loss elastic modulus, and loss tangent at 40 ° C. are shown in Table 2 and FIGS. Moreover, the temperature dependence of the storage elastic modulus is shown in FIG.

(Comparative Example 3)
PP was used in the same manner as in Example 7 except that graphite particles (“EXP-P” manufactured by Nippon Graphite Industry Co., Ltd., particle diameter: 100 to 600 μm) were used instead of the fine graphite particles treated with terminal chlorinated polyolefin. A resin composite material was prepared and a test piece was prepared. A photograph of the obtained test piece is shown in FIG. Further, the elastic modulus of this test piece was measured in the same manner as in Example 7. The storage elastic modulus, loss elastic modulus, and loss tangent at 40 ° C. are shown in Table 2 and FIGS.

(Comparative Example 4)
A PP resin composite material was prepared in the same manner as in Comparative Example 3 except that the amount of the graphite particles “EXP-P” was changed to 10 parts by mass, and the amount of the isotactic polypropylene was changed to 90 parts by mass to prepare a test piece. . The elastic modulus of this test piece was measured in the same manner as in Example 7. The storage elastic modulus, loss elastic modulus, and loss tangent at 40 ° C. are shown in Table 2 and FIGS.

(Comparative Example 5)
A PP resin composite material was prepared in the same manner as in Comparative Example 3 except that the amount of the graphite particles “EXP-P” was changed to 20 parts by mass, and the amount of the isotactic polypropylene was changed to 80 parts by mass to prepare a test piece. . The elastic modulus of this test piece was measured in the same manner as in Example 7. The storage elastic modulus, loss elastic modulus, and loss tangent at 40 ° C. are shown in Table 2 and FIGS. Moreover, the temperature dependence of the storage elastic modulus is shown in FIG.

  In general, when a filler is added to a resin, the viscosity of the resin composite material increases with an increase in the amount added, and the torque during kneading increases, but as is apparent from the results shown in FIG. When fine graphite particles treated with polyolefin were added to PP resin, the increase in torque was relatively small even when the amount added was increased, and a PP resin composite material advantageous in molding was obtained. In particular, it has been found that when wet pulverization is performed when preparing the fine graphite particles according to the present invention, the torque tends to decrease as the amount of addition increases.

  As is clear from the results shown in FIG. 10, when the fine graphite particles treated with the terminal chlorinated polyolefin are added to the PP resin, the fine graphite particles are uniformly dispersed in the PP resin. Was confirmed (FIG. 10A). On the other hand, when graphite particles that were not refined were added, the aggregation of the graphite particles could be confirmed visually (FIG. 10B).

  As is apparent from the results shown in Table 2 and FIGS. 11 to 12, when the fine graphite particles treated with the terminal chlorinated polyolefin are added to the PP resin, the elastic modulus of the PP resin composite material increases as the addition amount increases. It was confirmed that it increased. Further, it has been found that the increasing tendency of the elastic modulus is larger than that in the case of adding non-fine graphite particles. Furthermore, it has been found that the increasing tendency of the elastic modulus does not depend on the dispersion treatment (ultrasonic treatment or wet pulverization treatment) of the graphite particles when preparing the fine graphite particles according to the present invention.

  As is clear from the results shown in FIG. 13, the PP resin composite materials (Examples 9 and 12) combined with the fine graphite particles treated with the terminal chlorinated polyolefin were converted into PP resin (Comparative Example 2) and fine particles. It was found that the tendency to increase the elastic modulus was maintained up to the vicinity of the melting point (150 ° C.) of the PP resin as compared with the PP resin composite material (Comparative Example 5) combined with the graphite particles that were not converted.

  As described above, according to the present invention, it is possible to easily disperse the refined graphite particles in the olefin resin.

  Therefore, since the resin composite material of the present invention is obtained by dispersing finely divided graphite particles in an olefin resin, the characteristics of the graphite particles such as electrical conductivity and thermal conductivity are sufficiently imparted to the olefin resin. It is useful as a part for automobiles (for example, resin molded body, resin for outer plate, sliding member, interior material), parts for electric / electronic devices (for example, heat dissipation material, package material).

Claims (6)

Plate-like graphite particles and the following formula (1) adsorbed on the plate-like graphite particles:
_{- (CH 2 -CHX) - (} 1)
(In formula (1), X represents a phenyl group, a naphthyl group, an anthracenyl group, or a pyrenyl group, and these groups may have a substituent.)
And at least one selected from the group consisting of an alkyl chain, an oligoolefin chain, and a polyolefin chain bonded to the aromatic vinyl copolymer. A resin composite material comprising: refined graphite particles each having a hydrocarbon chain and an olefin resin.   The resin composite material according to claim 1, wherein the fine graphite particles are present in a dispersed state in the olefin resin. The aromatic vinyl copolymer has a functional group,
The hydrocarbon chain is formed by bonding at least one selected from an alkyl compound, an oligoolefin, and a polyolefin having a site that reacts with the functional group to the functional group. The resin composite material according to claim 1 or 2.   The aromatic vinyl copolymer is at least selected from the group consisting of the vinyl aromatic monomer unit and (meth) acrylic acid, (meth) acrylates, (meth) acrylamides, vinylimidazoles and vinylpyridines. The resin composite material according to claim 3, further comprising another monomer unit derived from one kind of monomer.   The resin composite material according to claim 3 or 4, wherein the functional group is an amino group.   The site that reacts with the functional group is at least one selected from the group consisting of a chlorine atom, a carboxyl group, and a carboxylic acid anhydride group. The resin composite material described.