JP5517307B2 - Sliding member and manufacturing method thereof - Google Patents

Description

  The present invention relates to a sliding member and a manufacturing method thereof.

  Conventionally, a sliding member using graphite particles as a solid lubricant is known. For example, JP-A-2005-89514 (Patent Document 1) discloses molybdenum disulfide and scaly or scaly graphite and polytetrafluoroethylene by using at least one binder selected from polyamideimide, polyimide and epoxy resin. There is disclosed a sliding member provided with a film to which a solid lubricant composed of However, although conventional scaly or scaly graphite is generally handled as plate-like particles, there are almost no ideally flat particles, and secondary particles whose crystal planes are randomly oriented In actuality, graphite particles having a structure in which (001) crystal planes were uniformly stacked in parallel did not exist. For this reason, it is difficult to orient the (001) crystal plane of the graphite particles in the direction parallel to the sliding surface of the sliding member in the above-mentioned sliding member containing the graphite particles, and the low friction characteristics. An excellent sliding member could not be obtained.

  Japanese Patent Laid-Open No. 2007-270894 (Patent Document 2) discloses a sliding member including a coating layer containing plate-like crystal particles such as graphite particles bonded by a binder resin as a solid lubricant. The plate-like crystal grains have a crystal structure in which (00l) crystal planes (l is an integer of 1 or more) are stacked in parallel, and at least on the sliding surface of the sliding member, the orientation of the (00l) crystal plane is It is also disclosed that the index is 90% or more. However, in the conventional graphite particles, those having an orientation index of (00l) crystal plane of 90% or more are only cache graphite that exists in a small amount in nature, and are extremely expensive. Therefore, when ordinary graphite particles obtained from natural minerals are used in place of expensive cash graphite for cost reduction, as described above, the graphite particles are formed as secondary particles whose crystal planes are randomly oriented. Since there are few particles that are ideally flat, it is difficult to orient the (001) crystal plane of the graphite particles in a direction parallel to the sliding surface of the sliding member, resulting in low friction characteristics. An excellent sliding member could not be obtained. Furthermore, in the sliding member described in Patent Document 2, since the (00l) crystal plane is formed on the entire sliding surface, wear easily proceeds due to delamination of the plate-like crystal particles, and wear resistance is improved. Was not enough.

  On the other hand, Japanese Patent Application Laid-Open No. 2010-223288 (Patent Document 3) discloses a sliding member having an A surface containing highly oriented graphite and a B surface containing a material having higher wear resistance than the highly oriented graphite. It is also disclosed that the A surface and the B surface are provided in a direction parallel to the sliding direction and toward the sliding direction. However, in this sliding member, it is necessary to separately prepare the A surface and the B surface, and a sliding member that can be manufactured more simply has been demanded. Further, when highly oriented graphite is refined, its crystal structure cannot be maintained, so that it is difficult to form the A surface in a finely dispersed state with respect to the B surface. It was also difficult to improve friction and wear resistance.

JP 2005-89514 A JP 2007-270894 A JP 2010-223288 A

  The present invention has been made in view of the above-described problems of the prior art, and an object thereof is to provide a sliding member having a low coefficient of friction and excellent wear resistance and a method for manufacturing the same.

  As a result of intensive studies to achieve the above object, the inventors of the present invention have obtained finely divided flakes obtained by mixing and pulverizing graphite particles, a specific aromatic vinyl copolymer, and hydrogen peroxide. The present inventors have found that a sliding member having a low coefficient of friction and excellent wear resistance can be obtained by dispersing the graphite particles in a matrix base material made of resin or metal, and the present invention has been completed.

That is, the sliding member 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.)
Containing finely divided flaky graphite particles comprising an aromatic vinyl copolymer containing a vinyl aromatic monomer unit represented by: and a matrix substrate made of resin or metal,
The fine flaky graphite particles are dispersed in the matrix base material.

  In such a sliding member, the content of the fine flaky graphite particles is preferably 10 to 90% by mass, and the matrix substrate is selected from the group consisting of polystyrene, polyphenylene ether and polyamideimide. Those composed of at least one kind of resin are preferred. Further, the aromatic vinyl copolymer comprises the vinyl aromatic monomer unit and (meth) acrylic acid, (meth) acrylates, (meth) acrylamides, vinylpyridines, maleic anhydride and maleimides. Those having other monomer units derived from at least one monomer selected from the group are preferred.

The first manufacturing method of the sliding member of the present invention includes 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.)
A step of preparing a molten dispersion containing fine flaky graphite particles comprising an aromatic vinyl copolymer containing a vinyl aromatic monomer unit represented by formula (1) and a matrix substrate in a molten state comprising a resin or a metal And a step of solidifying the molten dispersion.

  In the first production method, the step of preparing the molten dispersion includes mixing the fine flaky graphite particles, the matrix base material or a precursor thereof, and a solvent to obtain the fine flaky graphite particles. Preferably, the method includes a step of preparing a dispersed solvent dispersion, and a step of preparing the molten dispersion by melting the matrix substrate after removing the solvent from the solvent dispersion.

Moreover, the second manufacturing method of the sliding member of the present invention includes 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.)
A fine flaky graphite particle comprising an aromatic vinyl copolymer containing a vinyl aromatic monomer unit represented by the following: a matrix substrate made of resin or metal or a precursor thereof, and a solvent, and a solvent The method includes a step of preparing a solvent dispersion in which flaky graphite particles are dispersed, and a step of removing the solvent from the solvent dispersion.

  The reason why a sliding member having a low friction coefficient and excellent wear resistance can be obtained by dispersing the fine flaky graphite particles according to the present invention in a matrix substrate made of resin or metal is not necessarily clear. Although not present, the present inventors infer as follows. That is, the refined flaky graphite particles according to the present invention have a crystal structure in which (001) crystal planes are uniformly stacked in parallel. When such fine flaky graphite particles are dispersed in a matrix substrate made of resin or metal, the dispersion liquid flows during molding of the sliding member or during film formation. The (001) crystal plane is likely to be parallel to the surface of the sliding member, and it is presumed that the orientation of the (001) crystal plane in the direction parallel to this surface also increases on the surface of the obtained sliding member. . And since the surface of a sliding member is parallel to a sliding direction, it is guessed that the (001) crystal plane of refined flaky graphite particles will show high orientation also to a sliding direction.

  When a sliding member containing such fine flaky graphite particles is slid, the fine flaky graphite particles on the sliding surface cause delamination due to friction, and the exfoliated plate-like graphite particles are friction counterparts. To form a transfer layer. The interaction force between the (001) crystal plane of the fine flaky graphite particles on the sliding surface and the (001) crystal plane of the transfer layer is dominated only by a small intermolecular force, and its shear resistance Is extremely small, it is assumed that the friction coefficient of the sliding surface is reduced.

  In addition, since the flaky graphite particles according to the present invention are uniformly dispersed on the sliding surface, the plate-like graphite particles delaminated from a wide range of the sliding surface are supplied to the surface of the counterpart material, A transfer layer is formed over the entire friction surface of the material. As a result, it is presumed that the shear resistance between the sliding surface and the friction surface of the counterpart material is further reduced, and the friction coefficient of the sliding surface is further reduced.

  Furthermore, on the sliding surface of the sliding member of the present invention, there are a region composed of a fine flaky graphite particle portion and a region composed of a matrix base material portion having a relatively high wear resistance. Even when a high surface pressure shear force is applied by sliding, the load is dispersed in the region composed of the matrix base material portion, and an excessive load load on the region composed of the fine flaky graphite particle portion is suppressed. It is assumed that excellent wear resistance can be obtained.

  On the other hand, when graphite particles that are not refined are dispersed in the matrix base material, the (001) crystal plane of the graphite particles is randomly oriented with respect to the surface of the sliding member. Although delamination of graphite particles on the surface hardly occurs and wear hardly occurs, a transfer layer of plate-like graphite particles is not formed on the counterpart material, and it becomes difficult to sufficiently reduce the friction coefficient of the sliding surface. Inferred.

  According to the present invention, a sliding member having a low coefficient of friction and excellent wear resistance can be obtained. In particular, it is possible to obtain a sliding member that exhibits a low coefficient of friction and excellent wear resistance even under dry wear conditions without lubricating oil or boundary friction conditions in which the oil film breaks.

4 is an optical micrograph of the surface of a molded body produced in Example 3. 6 is an optical micrograph of the surface of a molded body produced in Example 5. 6 is an optical micrograph of the surface of a molded body produced in Comparative Example 6. 1 is a schematic view showing a ring-on-plate type frictional wear test apparatus. It is a graph which shows the friction coefficient of the molded object produced in Examples 1-2 and Comparative Examples 1-3. It is a graph which shows the friction coefficient of the molded object produced in Examples 3-9 and Comparative Examples 4-6. It is a graph which shows the abrasion depth of the molded object produced in Examples 3-9 and Comparative Examples 4-6.

  Hereinafter, the present invention will be described in detail with reference to preferred embodiments thereof.

  First, the sliding member of the present invention will be described. The sliding member of the present invention comprises finely divided flaky graphite particles comprising plate-like graphite particles and a specific aromatic vinyl copolymer adsorbed on the plate-like graphite particles, and a matrix substrate made of resin or metal. In the sliding member, the fine flaky graphite particles are dispersed in the matrix base material.

<Refined flake graphite particles>
First, the refined flaky graphite particles according to the present invention will be described. The refined flaky graphite particles according to the present invention comprise plate-like graphite particles and an aromatic vinyl copolymer adsorbed on the plate-like graphite particles.

  The plate-like graphite particles are not particularly limited. For example, known graphite having a graphite structure (artificial graphite, natural graphite (for example, flaky graphite, massive graphite, earthy graphite)) should not be destroyed. What is obtained by grind | pulverizing is mentioned. Such plate-like graphite particles have a (001) crystal plane exhibiting high orientation in a direction parallel to the surface of the sliding member.

  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 0.3 to 30 nm. Further, the size of the plate-like graphite particles in the planar direction is not particularly limited. For example, the length in the major axis direction (major axis) is preferably 0.1 to 500 μm, more preferably 0.2 to 100 μm, The length (minor axis) in the minor axis direction is preferably 0.1 to 100 μm, and more preferably 0.1 to 50 μm. When the size and thickness of the plate-like graphite particles are in the above range, the orientation of the (001) crystal plane tends to be higher with respect to the direction parallel to the surface of the sliding member.

  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 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 finely divided flake shape Graphite particles tend to be highly dispersible in the matrix substrate and the solvent according to the present invention.

  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. In the present invention, a copolymer obtained by copolymerizing such an aromatic vinyl copolymer with another vinyl monomer can also be used as the aromatic vinyl copolymer according to the present invention.

  In such an aromatic vinyl copolymer, the vinyl aromatic monomer unit exhibits adsorptivity to the graphite particles, and the other monomer units include the matrix substrate and the solvent according to the present invention and functional groups in the vicinity of the graphite particle surface. Affinity is shown. Therefore, such an aromatic vinyl copolymer is adsorbed on the plate-like graphite particles to reduce the cohesive force between the plate-like graphite particles and has an affinity for the plate-like graphite particles with the matrix substrate and the solvent according to the present invention. It becomes possible to highly disperse the plate-like graphite particles in the matrix base material or the solvent according to the present invention.

  In addition, as described above, since vinyl aromatic monomer units are easily adsorbed on graphite particles, a copolymer having a higher vinyl aromatic monomer unit content increases the amount of adsorption on plate-like graphite particles, resulting in finer structures. The flaky graphite particles tend to be highly dispersible in the matrix substrate or the solvent according to the present invention. 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 adsorption amount of the aromatic vinyl copolymer to the plate-like graphite particles is lowered, and the dispersibility of the fine flaky graphite particles tends to be lowered. When the content of the vinyl aromatic monomer unit exceeds the above upper limit, the plate-like graphite particles are not given affinity with the matrix base material or the solvent according to the present invention, and the dispersibility of the fine flaky graphite particles is lowered. There is a tendency.

  Examples of the substituent that the group represented by X in the formula (1) may have include an alkoxy group (for example, a methoxy group), a carbonyl group, an amide group, an imide group, a carboxyl group, and a carboxylate group. In particular, an alkoxy group such as a methoxy group is preferable, and a methoxy group is more preferable from the viewpoint of improving the dispersibility of the fine flaky graphite particles.

  Examples of such vinyl aromatic monomer units include styrene monomer units, vinyl naphthalene monomer units, vinyl anthracene monomer units, vinyl pyrene monomer units, vinyl anisole monomer units, vinyl benzoate ester monomer units, and acetyl styrene monomer units. Among them, styrene monomer units, vinyl naphthalene monomer units, and vinyl anisole monomer units are preferable from the viewpoint of improving the dispersibility of the fine flaky graphite particles.

  Although there is no restriction | limiting in particular as another monomer unit which comprises the aromatic vinyl copolymer concerning this invention, (meth) acrylic acid, (meth) acrylates, (meth) acrylamides, vinylimidazoles, vinylpyridines More preferred are monomer units derived from at least one monomer selected from the group consisting of maleic anhydride and maleimides. By using such an aromatic vinyl copolymer containing other monomer units, the refined flaky graphite particles have improved affinity with the matrix substrate and the solvent according to the present invention, and the matrix group according to the present invention is improved. It becomes possible to highly disperse in a material or a solvent.

  Examples of the (meth) acrylates include alkyl (meth) acrylate, substituted alkyl (meth) acrylate (for example, hydroxyalkyl (meth) acrylate, aminoalkyl (meth) acrylate), and the like. Examples of the (meth) acrylamides include (meth) acrylamide, N-alkyl (meth) acrylamide, N, N-dialkyl (meth) acrylamide and the like.

  Examples of the vinylimidazoles include 1-vinylimidazole. Examples of the vinyl pyridines include 2-vinyl pyridine and 4-vinyl pyridine. Examples of the maleimides include maleimide, alkyl maleimide, aryl maleimide and the like.

  Among these other monomers, alkyl (meth) acrylate, hydroxyalkyl (meth) acrylate, aminoalkyl (meth) acrylate, N, N-dialkyl are used from the viewpoint of improving the dispersibility of the fine flaky graphite particles. (Meth) acrylamide, 2-vinylpyridine, 4-vinylpyridine, and arylmaleimide are preferable, and hydroxyalkyl (meth) acrylate, N, N-dialkyl (meth) acrylamide, 2-vinylpyridine, and arylmaleimide are more preferable, and phenylmaleimide Is particularly preferred.

  In the fine flaky 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 flaky graphite particles according to the present invention, a random copolymer or a block copolymer may be used as the aromatic vinyl copolymer. From the viewpoint of improving dispersibility, it is preferable to use a block copolymer.

In fine flaky 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 parts by mass is more preferable. When the content of the aromatic vinyl copolymer is less than the lower limit, the dispersibility of the fine flaky graphite particles tends to decrease because the adsorption of the aromatic vinyl copolymer to the plate-like graphite particles is insufficient. On the other hand, if 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.

  As described above, the fine flaky graphite particles according to the present invention have a high affinity with the matrix base material and the solvent according to the present invention. In the sliding member of the present invention, the matrix base material has a high degree of affinity. Further, it is excellent in dispersibility in a solvent. For example, as described later, the matrix base material according to the present invention and fine flaky graphite particles are mixed in a solvent in the present invention. In the case of manufacturing the sliding member, it is possible to easily and highly disperse the fine flaky graphite particles in the solvent, and the fine flaky graphite particles are uniformly dispersed in the matrix substrate. The sliding member of the present invention can be easily obtained.

  Next, the manufacturing method of the refined flaky graphite particle concerning this invention is demonstrated. Fine flaky 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 hydrogenated product, and a solvent. In addition, after the obtained mixture is pulverized, it can be produced by removing the solvent.

  As the graphite particles used as a raw material when producing fine flaky graphite particles according to the present invention (hereinafter referred to as “raw material graphite particles”), known graphite having a graphite structure (artificial graphite, natural graphite (for example, Scaly graphite, lump graphite, earthy graphite)). Among them, those that become plate-like graphite particles having a thickness in the above range by grinding are preferable. Examples of such raw material graphite particles include those obtained by agglomerating the plate-like graphite particles (primary particles) (secondary particles). Moreover, there is no restriction | limiting in particular as a particle diameter of such raw material graphite particle | grains, However, 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 amount of adsorption and the adsorption force of the aromatic vinyl copolymer to the plate-like graphite particles are increased, and the resulting fine flaky graphite is obtained. The particles tend to be highly dispersible in the matrix base material and the solvent according to the present invention.

  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 flaky 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 a hydrogen peroxide acts as an oxidant when producing fine flaky graphite particles according to the present invention, and facilitates peeling between carbon layers without destroying the graphite structure of the raw graphite particles. Is. 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 fine flaky graphite particles can be highly dispersed in the matrix substrate or the solvent according to the present invention. .

  Although there is no restriction | limiting in particular as a solvent used for manufacture of the said fine flaky graphite particle, Dimethylformamide (DMF), chloroform, dichloromethane, chlorobenzene, dichlorobenzene, N-methylpyrrolidone (NMP), toluene, dioxane, propanol, γ-picoline, acetonitrile, dimethyl sulfoxide (DMSO) and dimethylacetamide (DMAC) are preferable, and dimethylformamide (DMF), chloroform, dichloromethane, chlorobenzene, dichlorobenzene, N-methylpyrrolidone (NMP) and toluene are more preferable.

  When producing the refined flaky graphite particles according to the present invention, first, the raw graphite particles, the aromatic vinyl copolymer, the hydrogen peroxide, and the solvent are mixed. 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. When the mixing amount of the aromatic vinyl copolymer is less than the above lower limit, the dispersibility of the resulting fine flaky graphite particles tends to be lowered. On the other hand, when the upper limit is exceeded, the aromatic vinyl copolymer is a 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 flaky graphite particles tends to be reduced.On the other hand, when the upper limit is exceeded, the raw graphite particles are excessively oxidized, There exists a tendency for the electroconductivity of the obtained refined flaky graphite particle to fall.

  Next, the obtained mixture is pulverized and the raw graphite particles are pulverized into plate-like graphite particles by delamination. The aromatic vinyl copolymer is adsorbed on the surface of the plate-like graphite particles produced thereby, and fine flaky graphite particles excellent in dispersion stability in the matrix base material and the solvent according to the present invention are obtained. be able to.

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

<Matrix substrate>
Next, the matrix substrate according to the present invention will be described. The matrix substrate according to the present invention is made of a resin or metal having excellent wear resistance, and specifically, is a resin or metal having higher wear resistance than the fine flaky graphite particles according to the present invention. .

  The resin is not particularly limited as long as it is a resin having higher abrasion resistance than the fine flaky graphite particles. For example, thermoplastic general-purpose plastics such as polystyrene resin, polypropylene resin and acrylic resin, polyphenylene Thermoplastic engineering plastics such as ether resin, polyamide resin, polyacetal resin, polyethylene terephthalate resin, polybutylene terephthalate resin and ultra-high molecular weight polyethylene resin, polyamideimide resin, polyphenylene sulfide resin, polyether ether ketone resin, liquid crystal polymer resin, poly Thermoplastic superenes such as tetrafluoroethylene resin, polyetherimide resin, polyarylate resin, polysulfone resin, polyimide resin and polyetherimide resin Engineering plastics, epoxy resins, phenolic resins, bismaleimide resins, melamine resins, such as thermosetting resins such as polyurethane resins and unsaturated polyester resins. These resins may be used alone or in combination of two or more. Of these resins, polyphenylene ether resin, polyamide resin, polyacetal resin, polyethylene terephthalate resin, polybutylene terephthalate resin, and ultrahigh molecular weight polyethylene from the viewpoint of excellent wear resistance, heat resistance and mass productivity. Thermoplastic engineering plastics such as resin, polyamideimide resin, polyphenylene sulfide resin, polyetheretherketone resin, liquid crystal polymer resin, polytetrafluoroethylene resin, polyetherimide resin, polyarylate resin, polysulfone resin, polyimide resin and polyether Thermoplastic super engineering plastics such as imide resins are preferred.

  Further, the metal is not particularly limited as long as it is a metal having higher wear resistance than the fine flaky graphite particles, and is 600 ° C. or lower in order to uniformly disperse the fine flaky graphite particles. Any member can be used as long as it can obtain a liquid state by melting, electrical treatment, chemical conversion treatment, or the like and coat the member. Examples of such metals include low melting point metals such as tin, zinc, indium and bismuth, or metal carriers such as iron, chromium, nickel, cobalt, rhodium, copper and brass, and nickel-chromium, nickel-phosphorus, Nickel-tungsten, nickel-cobalt, nickel-boron, cobalt-tungsten, iron-nickel, iron-phosphorus, iron-tungsten, copper-nickel, tin-nickel, tin-silver, tin-indium, tin-copper, tin- What can coat | cover a member by electrical treatment or chemical conversion treatment, such as alloys, such as zinc, tin-cobalt, tin-bismuth, silver-iron, zinc-iron, and zinc-nickel, is mentioned. Among these metals, those having a Vickers hardness (HV) of 300 or more are preferable from the viewpoint of excellent wear resistance, and chromium, nickel-chromium, nickel-phosphorus, nickel-tungsten, nickel-cobalt are preferable. Alloys such as nickel-boron, cobalt-tungsten, iron-nickel, iron-tungsten are preferred.

<Sliding member>
The sliding member of the present invention contains the matrix base material and the fine flaky graphite particles dispersed in the matrix base material. Thus, by dispersing the fine flaky graphite particles in the matrix base material, a sliding member having a low friction coefficient and excellent wear resistance can be obtained.

  In such a sliding member, the content of the fine flaky graphite particles is preferably 10 to 90% by mass, more preferably 20 to 70% by mass, and more preferably 25 to 60% by mass with respect to the entire sliding member. Is particularly preferred. When the content of the fine flaky graphite particles is less than the lower limit, the friction coefficient of the sliding surface is not sufficiently reduced, and the wear resistance tends to be difficult to improve. However, the wear resistance tends to decrease.

<Sliding member manufacturing method>
The sliding member of the present invention is prepared, for example, by preparing a molten dispersion containing the fine flaky graphite particles and the matrix substrate in a molten state, and then molding the molten dispersion into a predetermined shape and solidifying the molten dispersion. Can be manufactured (first manufacturing method). In the first production method, the melt dispersion may be prepared by mixing the fine flaky graphite particles, the matrix base material and a solvent to disperse the fine flaky graphite particles. And then, after the solvent is removed from the solvent dispersion, the matrix substrate is melted. The melting temperature of the matrix substrate needs to be equal to or lower than the temperature at which graphite burns in the presence of oxygen (600 ° C.), and can be appropriately set within the range according to the type of the matrix substrate.

  Further, the sliding member of the present invention is prepared by mixing the fine flaky graphite particles, the matrix base material and a solvent to prepare a solvent dispersion in which the fine flaky graphite particles are dispersed. It is also possible to produce by removing the solvent (second production method). In the second production method, after removing the solvent from the solvent dispersion to prepare a composite in which the fine flaky graphite particles are dispersed in the matrix substrate, the composite is formed into a predetermined shape. Alternatively, the solvent dispersion may be applied to the substrate to form a coating film, and then the solvent may be removed by drying or heat-curing the coating film. Further, the composite may be subjected to molding after being mechanically pulverized as necessary.

  There are no particular limitations on the method for molding the sliding member in these methods, and examples include press molding, injection molding, transfer molding, and the coating method is not particularly limited, and examples include coating and spraying. It is done. Moreover, there is no restriction | limiting in particular also about molding conditions and coating conditions, According to the kind of matrix base material, etc., it can set suitably.

  In the method for producing a sliding member of the present invention, instead of the matrix base material, a precursor of a matrix base material such as a raw material monomer or oligomer of the resin, or a metal salt, a metal having a melting point of 600 ° C. or lower is used. It can also be used. That is, when the raw material monomer or oligomer is used as a precursor of the matrix base material, in the first production method, for example, the refined flaky graphite particles and the molten raw material monomer or oligomer are used. The sliding member of the present invention can be formed by preparing the melt dispersion to be contained and reacting and curing the raw material monomer and the oligomer in the melt dispersion by heating or the like. In the second production method, a solvent dispersion containing the fine flaky graphite particles, the raw material monomer, the oligomer and the solvent is prepared, and the solvent in the solvent dispersion is removed by heating or the like. The sliding member of the present invention can be formed by reacting and curing the raw material monomer and the oligomer while removing. On the other hand, when using the metal salt as a precursor of the matrix substrate, for example, in the second production method, solvent dispersion containing the fine flaky graphite particles, the metal salt and a solvent The sliding member of the present invention can be formed on the surface of the substrate by preparing a product and plating the surface of the substrate using the solvent dispersion.

  The solvent used for the preparation of the solvent dispersion is not particularly limited as long as it can uniformly disperse the fine flaky graphite particles. For example, it is exemplified as a solvent used for producing the fine flaky graphite particles. The thing which was done is mentioned. The concentration of the fine flaky graphite particles in the solvent dispersion is preferably 0.1 to 200 g / L, more preferably 1 to 100 g / L, per liter of the solvent. When the concentration of the fine flaky graphite particles is less than the lower limit, the consumption of the solvent tends to increase, which tends to be economically disadvantageous. As a result, the viscosity of the solvent dispersion increases and the fluidity tends to decrease. Moreover, as a density | concentration of the matrix base material in the said solvent dispersion, or its precursor, 0.1-200 g / L is preferable per 1L of solvents, and 1-100 g / L is more preferable. When the concentration of the matrix substrate is less than the lower limit, the solvent consumption increases and tends to be economically disadvantageous.On the other hand, when the upper limit is exceeded, the viscosity of the solvent dispersion increases and the fluidity is increased. It tends to decrease.

  In the manufacturing method of the sliding member of the present invention, the molten dispersion, the composite, and the solvent dispersion flow when the molten dispersion and the composite are molded or the solvent dispersion is applied. As a result, the (001) crystal plane of the fine flaky graphite particles is oriented in a direction parallel to the surface (sliding surface) of the sliding member, and the sliding member of the present invention has a low friction coefficient and excellent resistance. It becomes wearable.

  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.

(Preparation Example 1)
Styrene (ST) 0.67 g, N, N-dimethylmethacrylamide (DMMAA) 1.23 g, azobisisobutyronitrile 10 mg and toluene 5 ml were mixed, and a polymerization reaction was performed at 60 ° C. for 6 hours in a nitrogen atmosphere. . After standing to cool, it refine | purified by reprecipitation using chloroform-ether, and 1.0-g ST-DMMAA (35:65) random copolymer (Mn = 78000) was obtained.

  20 mg of graphite particles (“EXP-P” manufactured by Nippon Graphite Industries Co., Ltd., particle size 100 to 600 μm), 80 mg of urea-hydrogen peroxide inclusion complex, 20 mg of the ST-DMMAA (35:65) 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.

  The obtained graphite particle dispersion was filtered, the filter cake was collected and dried under reduced pressure, and then pulverized using a mortar to obtain fine flaky graphite particles (A). When the fine flaky graphite particles (A) were observed with a scanning electron microscope (SEM), they were refined into a thin plate having a length of about 5 to 50 μm, a width of about 5 to 30 μm, and a thickness of 10 to 300 nm. It was confirmed that

(Preparation Example 2)
12.5 g of graphite particles (“EXP-60M” manufactured by Nippon Graphite Industry Co., Ltd., particle diameter of about 300 μm), 12.5 g of urea-hydrogen peroxide inclusion complex, ST-DMMAA prepared in the same manner as Preparation Example 1 ( 35:65) 1.25 g of random copolymer and 500 ml of DMF were mixed, and wet pulverized 10 times using a wet atomizer ("Starburst Lab" manufactured by Sugino Machine Co., Ltd.) at room temperature and cylinder pressure of 200 MPa. Processing 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.

  Fine graphite flake graphite particles (B) were obtained from the obtained graphite particle dispersion in the same manner as in Preparation Example 1.

Example 1
To 30 ml of a chloroform solution in which 2250 mg of polystyrene (PS, manufactured by Aldrich, number average molecular weight 1 × 10 ⁵ ) was dissolved, 750 mg of the fine flaky graphite particles (A) obtained in Preparation Example 1 was added and refined by stirring. The flaky graphite particles (A) were dispersed. Chloroform was removed from the obtained dispersion, vacuum-dried, and then melt-kneaded at 150 ° C. for 3 minutes. The obtained melt dispersion was subjected to pressure molding at 120 ° C. for 30 minutes or more, and a molded body (diameter 31.5 mm, thickness 0. 0 mm) in which fine flaky graphite particles (A) were dispersed in PS resin by 25% by mass. 3 mm (hereinafter abbreviated as “FG (A) (25) / PS resin molding”)).

(Comparative Example 1)
3000 mg of polystyrene (PS, manufactured by Aldrich, number average molecular weight 1 × 10 ⁵ ) was added to 10 ml of chloroform, and the polystyrene was dissolved by stirring. A PS resin molded body (diameter 31.5 mm, thickness 0.3 mm) was produced in the same manner as in Example 1 except that this solution was used instead of the dispersion.

(Example 2)
Instead of 2250 mg of polystyrene (PS), 1125 mg of polystyrene (PS) and 1125 mg of poly (2,6-dimethyl-1,4-phenylene oxide) (PPE, Aldrich, number average molecular weight 1 × 10 ⁵ ) Used, in the same manner as in Example 1 except that the pressure molding temperature was changed to 160 ° C., molding in which 25% by mass of fine flaky graphite particles (A) were dispersed in a resin composition containing PS and PPE. A body (diameter: 31.5 mm, thickness: 0.3 mm. Hereinafter, abbreviated as “FG (A) (25) / (PS + PPE) resin molded body”) was produced.

(Comparative Example 2)
1500 mg of polystyrene (PS, manufactured by Aldrich, number average molecular weight 1 × 10 ⁵ ) and 1500 mg of poly (2,6-dimethyl-1,4-phenylene oxide) (PPE, manufactured by Aldrich, number average molecular weight 1 × 10 ⁵ ) Were added to 30 ml of chloroform, and these were dissolved by stirring. A resin molded body containing PS and PPE (diameter: 31.5 mm, thickness: 0.3 mm, hereinafter referred to as “(PS + PPE)” in the same manner as in Example 2 except that this solution was used instead of the dispersion. Abbreviated as “resin molded body”).

(Comparative Example 3)
PS and PS were obtained in the same manner as in Example 2 except that 750 mg of graphite particles (“EXP-P” manufactured by Nippon Graphite Industry Co., Ltd., particle diameter: 100 to 600 μm) was used instead of the fine flaky graphite particles (A). Molded product in which graphite particles (EXP-P) are dispersed in an amount of 25% by mass in a resin composition containing PPE (diameter: 31.5 mm, thickness: 0.3 mm. Hereinafter, “Gr (P) (25) / (PS + PPE ) Resin molded product ").

(Example 3)
It was obtained in Preparation Example 1 in 30 ml of N-methyl-2-pyrrolidone (NMP) solution in which 2250 mg of standard type polyamideimide (PAI (S), “HPC-5011-29” manufactured by Hitachi Chemical Co., Ltd.) was dissolved. 750 mg of the refined flaky graphite particles (A) was added, and the refined flaky graphite particles (A) were dispersed by stirring. The obtained solvent dispersion was put into chloroform or methanol to reprecipitate the composite of the fine flaky graphite particles (A) and the PAI (S) resin, and then filtered, and the filter cake was vacuumed at room temperature. Dried. The obtained composite was pulverized with a pulverizer to obtain a powdery molding material in which fine flaky graphite particles (A) were dispersed in a PAI (S) resin. This powdery molding material is charged into a press die and molded at 280 ° C. for 30 minutes or more to form a fine flaky graphite particle (A) dispersed in a PAI (S) resin by 25% by mass. A body (diameter: 31.5 mm, thickness: 0.3 mm. Hereinafter, abbreviated as “FG (A) (25) / PAI (S) resin molded body”) was produced.

Example 4
In the same manner as in Example 3 except that the amount of the standard type polyamideimide (PAI (S)) was changed to 1800 mg and the amount of the fine flaky graphite particles (A) was changed to 1200 mg, it was finely dispersed in the PAI (S) resin. A molded product (diameter 31.5 mm, thickness 0.3 mm, abbreviated as “FG (A) (40) / PAI (S) resin molded product”) in which the flaky graphite particles (A) are dispersed by 40 mass%. Produced.

(Example 5)
In the same manner as in Example 3 except that 750 mg of the fine flaky graphite particles (B) obtained in Preparation Example 2 was used in place of the fine flaky graphite particles (A), fine particles were added to the PAI (S) resin. A molded product (diameter 31.5 mm, thickness 0.3 mm, abbreviated as “FG (B) (25) / PAI (S) resin molded product”) in which 25% by mass of flaky graphite particles (B) are dispersed. Produced.

(Example 6)
Fine in the PAI (S) resin in the same manner as in Example 5 except that the amount of the standard type polyamideimide (PAI (S)) was changed to 1800 mg and the amount of the fine flaky graphite particles (B) was changed to 1200 mg. A molded body (diameter: 31.5 mm, thickness: 0.3 mm, abbreviated as “FG (B) (40) / PAI (S) resin molded body”) in which the flaky graphite particles (B) are dispersed by 40 mass%. Produced.

(Example 7)
Except for using 1800 mg of high-strength and high-heat-resistant polyamideimide (PAI (H), “HPC-9000-21” manufactured by Hitachi Chemical Co., Ltd.) instead of the standard type polyamideimide (PAI (S)) In the same manner as in Example 4, a molded product (diameter: 31.5 mm, thickness: 0.3 mm, “FG (A)”) in which 40% by mass of fine flaky graphite particles (A) was dispersed in PAI (H) resin. 40) / PAI (H) resin molded product ”).

(Example 8)
PAI (H) was the same as in Example 7 except that the amount of the high-strength / high heat-resistant polyamideimide (PAI (H)) was changed to 1200 mg and the amount of the fine flaky graphite particles (B) was changed to 1800 mg. Molded product in which fine flaky graphite particles (A) are dispersed by 60% by mass in resin (diameter 31.5 mm, thickness 0.3 mm, “FG (A) (60) / PAI (H) resin molded product” Abbreviated).

Example 9
PAI (H) was the same as in Example 7 except that the amount of the high-strength and high heat-resistant type polyamideimide (PAI (H)) was changed to 600 mg and the amount of the fine flaky graphite particles (B) was changed to 2400 mg. Molded product in which fine flaky graphite particles (B) are dispersed in an amount of 80% by mass in resin (diameter 31.5 mm, thickness 0.3 mm, “FG (A) (80) / PAI (H) resin molded product”) Abbreviated).

(Comparative Example 4)
3000 mg of standard type polyamideimide (PAI (S), “HPC-5011-29” manufactured by Hitachi Chemical Co., Ltd.) was added to 30 ml of NMP, and the polyamideimide was dissolved by stirring. The obtained solution was poured into chloroform or methanol to reprecipitate the PAI (S) resin, followed by filtration, and the filter cake was vacuum dried at room temperature. The obtained PAI (S) resin was pulverized with a pulverizer to obtain a powdery PAI (S) resin molding material. A PAI (S) resin molding (diameter 31.5 mm, thickness 0.3 mm) was produced in the same manner as in Example 3 except that this resin molding material was used.

(Comparative Example 5)
Except for using 3000 mg of high-strength and high-heat-resistant polyamideimide (PAI (H), “HPC-9000-21” manufactured by Hitachi Chemical Co., Ltd.) instead of the standard type polyamideimide (PAI (S)) In the same manner as in Comparative Example 4, a PAI (H) resin molded body (diameter 31.5 mm, thickness 0.3 mm) was produced.

(Comparative Example 6)
In the same manner as in Example 3, except that 750 mg of graphite particles (“EXP-60M” manufactured by Nippon Graphite Industry Co., Ltd., particle diameter of about 300 μm) was used instead of the fine flaky graphite particles (A), PAI (S ) Molded product (diameter 31.5 mm, thickness 0.3 mm, “Gr (60M) (25) / PAI (S) resin molded product”) in which 25% by mass of graphite particles (EXP-60M) are dispersed in the resin .) Was produced.

<Optical microscope observation>
The surface of the molded body produced in Example 3, Example 5 and Comparative Example 6 was observed with an optical microscope. In FIGS. 1-3, the optical microscope photograph of the surface of the molded object produced in Example 3, Example 5, and Comparative Example 6, respectively is shown. The white part is graphite particles, and the gray part is PAI (S) resin. As is clear from the results shown in FIG. 1, in the molded body produced in Example 3, the fine flaky graphite particles (A) are dispersed in the PAI (S) resin, and the size thereof is It was confirmed to be in the range of μm to 20 μm. As is clear from the results shown in FIG. 2, in the molded body produced in Example 5, the refined flaky graphite particles (B) had a PAI as compared to the refined flaky graphite particles (A). (S) It was confirmed that the resin was more uniformly dispersed in the resin, and the size was as fine as several μm or less.

  On the other hand, as is apparent from the results shown in FIG. 3, in the molded body produced in Comparative Example 6, the PAI was in the state of secondary particles having a size of 100 μm or more of graphite particles (EXP-60M) that were not refined. (S) It was found to be present in the resin.

<Friction and wear test>
The compacts produced in the examples and comparative examples were bonded onto SUS440C steel (Vickers hardness (HV) 700 ± 50) using an epoxy resin adhesive to produce plate test pieces. The plate test piece was subjected to a friction wear test under dry wear conditions in which no lubricating oil was used under the following test conditions using a ring-on-plate type friction wear test apparatus shown in FIG.

(Test conditions)
-Partner material: SUJ-2 cylindrical test piece (outer diameter φ25.6 mm, inner diameter φ20.0 mm, surface roughness Rzjis (JIS B 601) in which Vickers hardness (HV) was adjusted to 740 by repeated quenching and tempering −2001) = 0.3 μm, apparent contact area of the friction surface = 200 mm ² ).
-Sliding speed: 0.1 m / s (Examples 1-2 and Comparative Examples 1-3), 0.3 m / s (Examples 3-9 and Comparative Examples 4-6).
Test surface pressure: Loaded with a load of 20 kgf to be 1 MPa (Examples 1 and 2 and Comparative Examples 1 to 3) Loaded with a load of 100 kgf to be 5 MPa (Examples 3 to 9 and Comparative Examples 4 to 4) 6).
Test time: 3 minutes (total sliding distance: 18 m, Examples 1 and 2 and Comparative Examples 1 to 3), 180 minutes (total sliding distance: 3240 m, Examples 3 to 9 and Comparative Examples 4 to 6).
Test temperature: room temperature (20-28 ° C.).

  For each molded body, the average value of the friction coefficient (μ) for 30 seconds immediately before the end of the test was determined. Moreover, about the molded object produced in Examples 3-9 and Comparative Examples 4-6, the height difference of the sliding part after a friction abrasion test and a non-sliding part was measured using a stylus-type roughness meter, This was the wear depth. These results are shown in FIGS.

  As is clear from the results shown in FIG. 5, in the PS resin molded body (Comparative Example 1) and the (PS + PPE) resin molded body (Comparative Example 2), the friction coefficient is 0.40 or more immediately after the frictional wear test, The test was stopped due to significant wear.

  On the other hand, FG (A) (25) / PS molded body (Example 1) and FG (A) (25) / (PS + PPE) molded body in which fine flaky graphite particles according to the present invention are dispersed, and In Example 2, the friction coefficient was 0.20 or less, and it was confirmed that the friction was reduced by dispersing the fine flaky graphite particles according to the present invention. Further, it was found that the amount of wear was small and excellent wear resistance was exhibited.

  On the other hand, in the Gr (P) (25) / (PS + PPE) molded body (Comparative Example 3) in which graphite particles that are not refined are dispersed, the friction coefficient is 0.27, and the effect of dispersing the graphite particles is recognized. However, the effect was small compared with the refined flaky graphite particles according to the present invention.

  Further, as is clear from the results shown in FIGS. 6 to 7, in the PAI resin moldings (Comparative Examples 4 to 5), the friction coefficient became 0.40 or more immediately after the friction wear test, and the test was conducted. Canceled. Further, the wear amount was 200 μm or more, and the wear resistance was low.

  On the other hand, all of the compacts (Examples 3 to 9) in which 25 to 80% by mass of finely divided flaky graphite particles according to the present invention are dispersed have a friction coefficient of 0.13 or less, and the present invention is applied. It was confirmed that the friction was reduced by dispersing the fine flaky graphite particles. Moreover, although it was a test with a long sliding distance, it was confirmed that the SUS440C steel material is not exposed after the test and exhibits excellent wear resistance. In particular, when the content of the fine flaky graphite particles according to the present invention is 25 to 60% by mass (Examples 3 to 8), the friction depth is 100 μm or less, and the wear resistance is higher. I found out.

  On the other hand, in the case of the Gr (60M) (25) / PAI (S) molded body (Comparative Example 6) in which the non-fine graphite particles are dispersed, the fine flaky graphite particles according to the present invention are dispersed. Compared to the above, although the wear depth is small and excellent wear resistance is exhibited, the friction coefficient is 0.17, and it is difficult to sufficiently reduce the friction even if non-fine graphite particles are dispersed. I understood it.

  As described above, according to the present invention, a sliding member having a low coefficient of friction and excellent wear resistance can be obtained.

  Therefore, by using the sliding member of the present invention on the sliding surfaces of various machine parts, it is possible to reduce friction loss and maintain smooth operation of the machine. In particular, in an automobile drive system unit such as an engine, an automatic transmission, a manual transmission, and a reduction gear, the friction loss can be kept low over a long period.

  1: Plate test piece, 1a: SUS440C steel material, 1b: Molded body, 1c: Sliding part, 1d: Non-sliding part, 2: SUJ-2 cylindrical test piece.

Claims (7)

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.)
Containing finely divided flaky graphite particles comprising an aromatic vinyl copolymer containing a vinyl aromatic monomer unit represented by: and a matrix substrate made of a resin or metal,
The sliding member, wherein the fine flaky graphite particles are dispersed in the matrix substrate.   The sliding member according to claim 1, wherein the content of the fine flaky graphite particles is 10 to 90% by mass.   The sliding member according to claim 1 or 2, wherein the matrix base material is made of at least one resin selected from the group consisting of polystyrene, polyphenylene ether, and polyamideimide.   The aromatic vinyl copolymer is selected from the group consisting of the vinyl aromatic monomer unit and (meth) acrylic acid, (meth) acrylates, (meth) acrylamides, vinyl pyridines, maleic anhydride and maleimides The sliding member according to any one of claims 1 to 3, further comprising another monomer unit derived from at least one kind of monomer. 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.)
Fine flaky graphite particles comprising an aromatic vinyl copolymer containing a vinyl aromatic monomer unit represented by the formula (1) and a molten dispersion containing a matrix substrate or a precursor thereof in a molten state made of resin or metal A step of preparing
Solidifying the molten dispersion;
The manufacturing method of the sliding member characterized by including. Preparing the melt dispersion comprises:
Mixing the fine flaky graphite particles, the matrix substrate or a precursor thereof, and a solvent to prepare a solvent dispersion in which the fine flaky graphite particles are dispersed; and
Removing the solvent from the solvent dispersion, and then melting the matrix substrate or its precursor to prepare the melt dispersion;
The manufacturing method of the sliding member of Claim 5 characterized by the above-mentioned. 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.)
A fine flaky graphite particle comprising an aromatic vinyl copolymer containing a vinyl aromatic monomer unit represented by the following: a matrix substrate made of resin or metal or a precursor thereof, and a solvent, and a solvent Preparing a solvent dispersion in which flaky graphite particles are dispersed;
Removing the solvent from the solvent dispersion;
The manufacturing method of the sliding member characterized by including.