JP4993908B2 - Resin composition, sliding member and sliding device - Google Patents

Description

  The present invention relates to a resin composition, a sliding member, and a sliding device having both a low coefficient of friction and excellent wear resistance. More specifically, the present invention is suitably used in the presence of a lubricant such as lubricating oil or hydraulic oil. The present invention relates to a resin composition, a sliding member in which the resin composition is applied to a sliding portion, a sliding device to which the sliding member is applied, and an automobile piston.

In internal combustion engines, higher rotation, higher compression ratio, lighter weight, and improved fuel efficiency are more strongly demanded than ever before.
In order to realize such a demand, it is necessary to reduce friction and improve wear resistance and seizure resistance at the sliding portion.

  In addition, as one of the measures to realize low friction and improved wear resistance and seizure resistance at the sliding part, binders such as polyamide imide, polyimide, epoxy and the like, molybdenum disulfide, graphite, polytetrafluoro A method of coating a lubricating paint formed by blending a solid lubricant such as ethylene is employed.

  Specifically, at least one of polyamide-imide and polyimide is 50 to 73 wt% as a binder, polytetrafluoroethylene 3 to 15 wt%, molybdenum disulfide 20 to 30 wt%, and graphite 2 as a solid lubricant. A sliding resin composition characterized by adding a total of 27 to 50 wt% solid lubricant in the range of ˜8 wt% is disclosed (see Patent Document 1).

A film comprising a dry film lubricant comprising a polyamide-imide resin, at least one film modifier selected from epoxy silane and epoxy resin, and at least one hard particle selected from silicon nitride and alumina. The layer is formed on at least a part of the surface that becomes the sliding surface of the base material, and at least a part of the surface that becomes the sliding surface of the base material has a surface roughness of 10 to 18 μmRz in terms of a 10-point average roughness. A sliding member having streaks is disclosed (see Patent Document 2).
Japanese Patent No. 3017626 JP 2004-149622 A

However, in the sliding resin composition described in Patent Document 1, the friction reduction of the sliding part is achieved mainly by adding polytetrafluoroethylene, but in the presence of lubricating oil, Since polytetrafluoroethylene inhibits the lipophilicity of the resin composition, the addition amount is limited from the viewpoint of ensuring wettability.
For this reason, the friction reduction effect is limited, and it is difficult to obtain a further friction reduction effect.

  Further, the coating layer made of the dry coating lubricant described in Patent Document 2 improves the wear resistance of the sliding member. However, since the friction of the sliding member depends on the friction coefficient of the base resin, the friction is reduced. In order to reduce it, it is necessary to add a solid lubricant such as polytetrafluoroethylene, molybdenum disulfide, graphite, etc., which is still insufficient from the viewpoint of friction.

  The present invention has been made in view of such problems of the prior art, and the object of the present invention is to be suitably used in the presence of a lubricant such as lubricating oil or hydraulic oil, and to have a low coefficient of friction and excellent performance. Another object of the present invention is to provide a resin composition having both wear resistance, a sliding member in which the resin composition is applied to a sliding part, a sliding device to which the sliding member is applied, and an automobile piston.

  As a result of intensive studies to achieve the above object, the present inventors have made a polyamide resin, a polysulfone resin, a polyetherimide resin, a polyethersulfone resin, a polyamideimide resin, a polyimide resin, a polyetheretherketone resin, and an epoxy resin. At least one base resin selected from the group consisting of: a fluororesin having a surface energy of 200 to 400 μN / cm and a visible light transmittance of 10% or more at a wavelength of 600 nm; and a Mohs hardness of 1 to The present inventors have found that the above object can be achieved by using a resin composition containing graphite 2 and the present invention has been completed.

That is, the resin composition of the present invention is contained in a coating formed on at least a part of the sliding portion of the base material of the sliding member that slides in the presence of the lubricant, and the base resin and the fluororesin A resin composition comprising graphite, and the base resin is polyamide resin, polysulfone resin, polyetherimide resin, polyethersulfone resin, polyamideimide resin, polyimide resin, polyetheretherketone resin and epoxy resin. The fluororesin has a surface energy of 200 to 400 μN / cm, and the fluororesin has a visible light transmittance of 10% or more at a wavelength of 600 nm. , and the content thereof in the fluororesin is from 10 to 30% based on the resin composition the total amount, such graphite, the graphite Wherein the Mohs hardness of 1-2.

Further, the sliding member of the present invention is characterized by the formation Turkey by applying the resin composition of the present invention.
As a specific embodiment of such a sliding member, for example, an automobile piston formed by applying a coating film containing a resin composition to the piston skirt can be cited.

Furthermore, the sliding device of the present invention is characterized by a Turkey which a sliding member of the present invention.

According to the present invention, the matrix resin comprises a matrix resin, a fluororesin, and graphite, and the matrix resin includes a polyamide resin, a polysulfone resin, a polyetherimide resin, a polyethersulfone resin, a polyamideimide resin, a polyimide resin, Containing at least one selected from the group consisting of a polyether ether ketone resin and an epoxy resin, the fluororesin having a surface energy of 200 to 400 μN / cm, and the fluororesin at a wavelength of 600 nm The visible light transmittance is 10% or more, the fluororesin content is 10 to 30% based on the total amount of the resin composition, and the graphite has a Mohs hardness of 1 to 2 and the like be used to coat the objects on the form at least a portion of the sliding portion of the base material of the sliding member that slides in the presence of a lubricant Therefore, a resin composition that is preferably used in the presence of a lubricant such as lubricating oil or hydraulic oil, and has both a low friction coefficient and excellent wear resistance, a sliding member in which the resin composition is applied to a sliding portion, A sliding device to which a sliding member is applied and a piston for an automobile can be provided.

  Hereinafter, the resin composition of the present invention will be described in detail. In the present specification and claims, “%” represents mass percentage unless otherwise specified.

As described above, the resin composition of the present invention is contained in the coating formed on at least a part of the sliding portion of the base material of the sliding member that slides in the presence of the lubricant. It contains resin and graphite.
Such a matrix resin includes a polyamide resin, a polysulfone resin, a polyetherimide resin, a polyethersulfone resin, a polyamideimide resin, a polyimide resin, a polyetheretherketone resin or an epoxy resin, and a matrix according to any combination thereof. Contains material resin.
Further, such a fluororesin is the surface energy of ranging from 200 to 400 N / cm of the fluororesin, and Der visible light transmittance of 10% or more at a wavelength of 600nm of fluorine resin is, the content of the fluororesin, the resin Ru 10-30% der whole composition as the reference.
Further, such graphite has a Mohs hardness of 1-2.

Here, as the base material resin to be contained, when the resin composition is formed, it is desirable to have heat resistance according to the use environment.
For example, when applied to an internal combustion engine for automobiles, it is desirable that the components of the internal combustion engine for automobiles have a heat resistance of 150 ° C. or higher because the component temperature rises to about 150 ° C.
In order to measure whether or not the heat resistance is 150 ° C. or higher, for example, it is measured whether or not the heat deformation temperature under the 1.8 MPa stress action defined by ISO 75 is 150 ° C. or higher in an unstrengthened state. do it.

  Further, as will be described in detail later, the resin composition of the present invention may be used by covering at least a part of the sliding portion of the substrate as one of its usage modes, for example, air spray or screen printing. It is desirable that the base resin material be easily formed into a film by coating by dipping or the like.

  As the base resin satisfying these conditions, typically, the above-mentioned thermoplastic resins such as polyamide resin, polysulfone resin, polyetherimide resin, polyethersulfone resin, polyamideimide resin, polyimide resin, polyetherether are used. Examples thereof include a ketone resin and an epoxy resin which is a thermosetting resin. These may be mixed as appropriate or copolymerized.

  In addition, from the viewpoint of having a glass transition temperature of 250 ° C. or higher and high heat resistance, and having a cross-linked structure in the molecular chain, the coating film is strong, and further, excellent adhesion to the substrate is used. It is desirable to contain it as a base material resin.

  When a polyamideimide resin is applied as a base resin, the number average molecular weight of the polyamideimide resin material is preferably 1000 to 10000 before being dried or fired to form a film, and is 2000 to 8000. Is more preferable, and it is still more preferable that it is 4000-8000.

When the number average molecular weight is less than 1000, there is little entanglement of molecular chains, and thus the abrasion resistance of the resin composition may be lowered.
On the other hand, when the number average molecular weight exceeds 10,000, the friction coefficient of the polyamideimide resin as a base resin increases, and as a result, the friction coefficient of the resin composition may increase. Moreover, the adhesiveness with the base material of a resin composition may fall, and it may become easy to generate | occur | produce peeling.

  Moreover, the fluororesin to be contained needs to have a surface energy of 200 to 400 μN / cm and a visible light transmittance of 10% or more at a wavelength of 600 nm.

Generally, the surface energy of lubricants such as lubricating oil and hydraulic oil is about 250 to 350 μN / cm. On the other hand, the surface energy of a general fluororesin applied for reducing friction is about 170 to 200 μN / cm. Therefore, when a general fluororesin is applied under lubrication conditions, it has an affinity for oil. Therefore, even if a fluororesin is contained, the effect of reducing friction as in a non-lubricated condition cannot be obtained.
Therefore, in the present invention, an oil film is obtained by modifying the surface energy of the fluororesin to the range of 200 to 400 μN / cm, preferably by modifying the surface energy to the range of 250 to 350 μN / cm. Generation and adsorption of additives in oil are not hindered, and a synergistic effect between the oil film and the solid lubricant can be exhibited.

  In addition, since the fluororesin has low friction, the wear resistance is inferior. When a general fluororesin is contained, the area around the fluororesin is selectively worn, resulting in a resin composition. There is a tendency for overall wear to increase.

  In order to improve the wear resistance of the fluororesin, it is effective to reduce the crystal size. That is, by reducing the crystal size, the fluidity of the crystal is increased and the transfer to the counterpart material is facilitated, the generation of the transfer film is promoted, and the wear resistance can be improved. Further, wear resistance can be improved by reducing the size of the wear powder.

  The size of the crystal can be determined by the visible light transmittance. For example, as described above, by setting the visible light transmittance at a wavelength of 600 nm of the fluororesin to 10% or more, sufficient wear resistance is obtained. Sex can be obtained.

  As described above, a fluororesin having a surface energy of 200 to 400 μN / cm and a visible light transmittance of 10% or more at a wavelength of 600 nm is, for example, in an inert gas atmosphere having an oxygen partial pressure of 1333 Pa or less. It can be obtained by heating above the melting point, irradiating the fluororesin raw material with ionizing radiation in the range of 1 to 10 kGy, and then applying thermal energy in the presence of oxygen.

  In addition, the above-mentioned modified fluororesin has an increased amount of unsaturated bonds as compared with conventional fluororesins, and when added to a resin composition, the unsaturated fluorocarbon resin in the molecular chain of the fluororesin is used. When the bond reacts with, for example, a functional group of the base resin, a secondary effect of improving the adhesion between the base resin and the fluororesin is also exhibited.

Moreover, in the resin composition of this invention, it is preferable that the fluororesin to contain is a fluororesin particle with an average particle diameter of 1-50 micrometers, and it is more preferable that it is a fluororesin particle with an average particle diameter of 1-30 micrometers. .
When the average particle size of the fluororesin particles is less than 1 μm, it becomes difficult to uniformly disperse in the matrix resin, whereas when the average particle size exceeds 50 μm, the particles become coarse particles. There is a possibility that the strength of the base material resin, particularly impact strength and fatigue strength, may be reduced.

Further, in the resin composition of the present invention requires that the content of the fluorine resin is 1 0-30% referenced to the resin composition the total amount.
When the content of the fluororesin is less than 5%, a sufficient friction reducing effect may not be obtained. On the other hand, when the content exceeds 40%, the fluororesin may be further contained. Since the effect of reducing friction is saturated and the content of the fluororesin having low mechanical strength increases, the mechanical properties of the resin composition may be greatly deteriorated.

  On the other hand, the graphite contained needs to have a Mohs hardness of 1-2.

When only the fluororesin as described above is contained in the base material resin, the wear resistance is lowered due to the presence of the fluororesin having a lower hardness than the base material resin.
Therefore, in the present invention, in order to achieve both low friction and ensuring wear resistance, it is necessary to contain graphite having the Mohs hardness of 1 to 2 together with the above fluororesin in the base material resin.
Graphite is harder than the base resin and has low shear strength at specific crystal planes, so it is generally added as a filler from the viewpoint of ensuring low friction and wear resistance. In many cases, the Mohs hardness of graphite is defined as 1 to 2 in the present invention.
When the Mohs hardness of the graphite is less than 1, there is almost no effect of improving the wear resistance. On the other hand, when the Mohs hardness exceeds 2, the graphite bites into the sliding counterpart material, and the friction increases. This is because the wear of the mating material is promoted particularly when the sliding mating material is a soft metal such as an aluminum alloy.

Moreover, in the resin composition of this invention, it is preferable that the graphite to contain is a graphite particle with an average particle diameter of 1-30 micrometers, and it is more preferable that it is a graphite particle with an average particle diameter of 1-10 micrometers.
When the average particle size of the graphite particles is less than 1 μm, it becomes difficult to uniformly disperse in the matrix resin. On the other hand, when the average particle size exceeds 30 μm, the particles become coarse particles. There is a possibility that the strength of the material resin, particularly impact strength and fatigue strength may be lowered, and the smoothness of the resin composition may be lowered to deteriorate the friction.

Furthermore, in the resin composition of the present invention, it is desirable that the shape of the graphite contained is a scaly shape whose orientation direction can be controlled by making the resin composition thin.
By orienting the scale-like graphite particles in parallel with the sliding direction, not only friction can be reduced, but also the edge of the graphite particles becomes difficult to be exposed, so that the attack of the counterpart material is reduced.
In the case of scaly graphite particles, the average particle diameter may be defined using a laser diffraction particle size analyzer.

Furthermore, in the resin composition of the present invention, the graphite content is preferably 2 to 40%, more preferably 2 to 10%, based on the total amount of the resin composition.
When the graphite content is less than 2%, the effect of improving the wear resistance is not observed. On the other hand, when the graphite content exceeds 40%, the smoothness of the resin composition decreases. In addition, the friction increases, and the effect of reducing the friction due to the inclusion of the fluororesin may be lost.

Next, the sliding member and the sliding device of the present invention will be described in detail.
As described above, the sliding member of the present invention is also of Ru formed by applying the resin composition of the present invention.
The Rukoto apply such a resin composition, to reduce the coefficient of friction when sliding, it is possible to improve the wear resistance. Moreover, you may form a film in the whole surface of a sliding site | part.
Here, the “base material” is not particularly limited, but for example, metals such as iron-based alloys and aluminum alloys, resins such as polyetheretherketone and polyphenylene sulfide, carbon materials such as carbon fiber reinforced plastics, etc. Can be used.
As described above, the sliding member of the present invention can include, for example, an automobile piston applied to the skirt portion of the piston as one aspect thereof, and as another aspect, for example, sliding of a bearing or an artificial joint. Although a part etc. can be mentioned, it is not limited to these.

Furthermore, in the sliding member of the present invention, the thickness of the coating is preferably 2 to 70 μm, and more preferably 2 to 50 μm.
When the film thickness is less than 2 μm, it is difficult to maintain sufficient durability, while when the film thickness exceeds 70 μm, it is difficult to produce a uniform film.

Furthermore, in the sliding member of the present invention, the surface roughness of the sliding part is 15 μm or less in terms of the maximum surface roughness Rz, and the wear resistance of the resin composition of the present invention is more effectively exhibited. It is preferable from a viewpoint that it can do, More preferably, it is 10 micrometers or less, It is especially preferable that it is 8 micrometers or less.
This is because when the surface roughness of the sliding portion exceeds 15 μm in terms of the maximum surface roughness Rz, the contact surface pressure at the apex of the convex portion increases and the amount of wear of the resin composition increases.

Further, the sliding device of the present invention is the equipment with the sliding member of the present invention.
Here, as the “lubricant”, for example, a conventionally known lubricating oil or hydraulic oil can be suitably used, and grease, water, alcohol, etc. can be added and used, but a friction modifier is particularly added. It is desirable to use a lubricating oil.

  EXAMPLES Hereinafter, although an Example and a comparative example demonstrate this invention further in detail, this invention is not limited to these Examples.

Example 1
<Preparation of fluororesin powder>
Tetrafluoroethylene molding powder (G163, manufactured by Asahi Glass Co., Ltd.) is irradiated with an electron beam (pressurized voltage 2 MeV) at an irradiation dose of 100 kGy under an atmosphere with an oxygen partial pressure of 133 Pa and a nitrogen partial pressure of 106657 Pa under heating conditions of 350 ° C. Then, the tetrafluoroethylene was modified, and then pulverized with a jet mill until the average particle size became 10 μm to obtain a tetrafluoroethylene-modified powder. This was designated as fluororesin powder 1.

<Preparation of resin composition precursor>
With respect to 75 parts by mass of a polyamideimide resin material (number average molecular weight: 6000) synthesized by an isocyanate method using N-methyl-2-pyrrolidone (NMP) as a solvent, 20 parts by mass of the fluororesin powder 1 and graphite powder ( 5 parts by mass of artificial graphite, Mohs hardness: 2, average particle size: 4 μm, shape: scale-like) was added, and the mixture was stirred for 30 minutes with a bead mill to obtain a resin composition precursor. This was designated as resin composition precursor 1.

<Production of sliding member>
The resin composition precursor 1 is formed on a degreased aluminum alloy AC8A plate (25 × 75 × 15 mm, maximum longitudinal surface roughness Rz = 10 μm) as a base material so that the film thickness becomes 20 ± 5 μm. The sliding member of this example was obtained by coating with air spray and baking in air at 180 ° C. for 60 minutes to form a coating of the resin composition.
In the obtained resin composition coating, it was confirmed by measuring the contact angle between water and methylene iodide that the surface energy of the fluororesin was 280 μN / cm, and the visible light transmittance of the fluororesin at a wavelength of 600 nm was 23. %, It was confirmed by the method of JIS K7361, and it was confirmed by a Mohs hardness tester that the Mohs hardness of graphite was 2.

(Example 2)
<Preparation of resin composition precursor>
With respect to 69 parts by mass of polyamideimide resin material (number average molecular weight: 2000) synthesized by isocyanate method using NMP as a solvent, 20 parts by mass of the fluororesin powder 1 and graphite powder (artificial graphite, Mohs hardness: 2, average) 6 parts by mass of particle size: 4 μm, shape: scaly, 5 parts by mass of polyetheretherketone resin powder (manufactured by Victorex MC, 450PF, average particle size: 3 μm), and stirred for 30 minutes in a bead mill, A resin composition precursor was obtained. This was designated as resin composition precursor 2.

<Production of sliding member>
Except using the said resin composition precursor 2, the same operation as preparation of the sliding member of Example 1 was repeated, and the sliding member of this example was obtained.
In addition, in the coating film of the obtained resin composition, the surface energy of the fluororesin is 280 μN / cm and the visible light transmittance at a wavelength of 600 nm of the fluororesin is 23% in the same manner as in Example 1. It was confirmed that the Mohs hardness was 2.

(Comparative Example 1)
<Preparation of resin composition precursor>
Polytetrafluoroethylene powder (manufactured by Asahi Glass Co., Ltd., L150J (emulsion polymerization type)), average particle diameter: 10 μm with respect to 65 parts by mass of polyamideimide resin material (number average molecular weight: 2000) synthesized by isocyanate method using NMP as a solvent ) 10 parts by mass, molybdenum disulfide powder (manufactured by Sumiko Lubricant Co., Ltd., average particle size 1.5 μm), 20 parts by mass, graphite powder (artificial graphite, Mohs hardness: 2, average particle size: 4 μm, shape: scale 5 parts by mass was added, and the mixture was stirred for 30 minutes with a bead mill to obtain a resin composition precursor. This was designated as resin composition precursor 3.

<Production of sliding member>
Except using the said resin composition precursor 3, the same operation as preparation of the sliding member of Example 1 was repeated, and the sliding member of this example was obtained.
In addition, in the coating film of the obtained resin composition, the surface energy of the fluororesin is 190 μN / cm, the visible light transmittance of the fluororesin at a wavelength of 600 nm is 0% in the same manner as in Example 1, and the graphite It was confirmed that the Mohs hardness was 2.

(Comparative Example 2)
<Preparation of resin composition precursor>
Polytetrafluoroethylene powder (manufactured by Asahi Glass Co., Ltd., L150J (emulsion polymerization type)), average particle diameter: 10 μm with respect to 80 parts by mass of polyamideimide resin material (number average molecular weight: 2000) synthesized by isocyanate method using NMP as a solvent 10 parts by mass of alumina powder (manufactured by Admatechs, A0-900H, average particle size: 5 μm) was added, and the mixture was stirred with a bead mill for 1 hour to obtain a resin composition precursor. This was designated as resin composition precursor 4.

<Production of sliding member>
Except using the said resin composition precursor 4, the same operation as preparation of the sliding member of Example 1 was repeated, and the sliding member of this example was obtained.
In addition, in the coating film of the obtained resin composition, the surface energy of the fluororesin is 190 μN / cm and the visible light transmittance at a wavelength of 600 nm of the fluororesin is 0% by the same method as in Example 1. confirmed.

(Comparative Example 3)
<Preparation of resin composition precursor>
20 parts by mass of the fluororesin powder 1 is added to 80 parts by mass of a polyamide-imide resin material (number average molecular weight: 6000) synthesized by an isocyanate method using NMP as a solvent, and stirred for 30 minutes by a bead mill. A product precursor was obtained. This was designated as resin composition precursor 5.

<Production of sliding member>
Except using the said resin composition precursor 5, the same operation as preparation of the sliding member of Example 1 was repeated, and the sliding member of this example was obtained.
In the film of the resin composition thus obtained, the surface energy of the fluororesin was 280 μN / cm and the visible light transmittance at a wavelength of 600 nm of the fluororesin was 23% in the same manner as in Example 1. confirmed.

[Evaluation test]
(Friction test)
In order to grasp the friction characteristics of the resin composition of the present invention, the friction test of the sliding members of Examples 1 to 3 and Comparative Examples 1 and 2 was performed under engine oil dropping conditions.

For the measurement of the friction characteristics, a reciprocating friction tester (Kyowa Giken, FRICTION ANALYZER RTF-3) of a type in which a cylindrical test piece is pressed on a reciprocating plate was used. The material to be slidably contacted is an FCA material having a Rockwell hardness of 95 to 103 HRB, a surface roughness of about 0.2 μmRa on the center line average roughness, and the shape of the mating material is a circle having a diameter of 8 mm and a height of 25 mm. It was columnar.
On the other hand, Nissan engine oil SJ Strong Save XM Special 5W-30 was used as the engine oil dropped on the sliding surface.

  FIG. 1 is an explanatory diagram showing an outline of the friction test. As shown in the figure, in carrying out the friction test, the longitudinal direction of the plate on the slide base 10 reciprocating the aluminum alloy AC8A plate 1 coated with the resin composition is parallel to the slide base movement direction indicated by the arrow A. The cylindrical test piece 20 made of FCA was attached so that the longitudinal direction of the test piece was orthogonal to the moving direction of the slide base.

Next, a vertical load of 980 N indicated by an arrow B was applied to the FCA test piece (indenter) 20 from the top, and 2 cc of engine oil was dropped onto the pressure contact portion between the FCA test piece and the resin composition.
The moving amount of the slide table on which the aluminum alloy AC8A plate coated with the resin composition was installed was 50 mm, and the moving speed was 1.0 m / sec. The friction test was carried out for a total of 18000 cycles, and the waveform of the friction coefficient at the time of one reciprocation every 3000 cycles from the start of the test was taken into a measuring instrument to obtain the static friction coefficient and the dynamic friction coefficient. The change with time of the static friction coefficient is shown in FIG.

  From FIG. 2, the static friction coefficients of Examples 1 and 2 and Comparative Example 3 are lower than those of Comparative Examples 1 and 2. This is because a fluororesin having a surface energy contained in the resin composition of 200 to 400 μN / cm and a visible light transmittance of 10% or more at a wavelength of 600 nm effectively functions as a solid lubricant even under oil lubrication. It is thought to be because.

  Next, the change with time of the dynamic friction coefficient is shown in FIG. From FIG. 3, for Examples 1 and 2 and Comparative Example 3, a tendency to be lower than those of Comparative Examples 1 and 2 is recognized, similarly to the static friction coefficient. The dynamic friction coefficients of Examples 1 and 2 and Comparative Example 3 are decreased because the surface energy contained in the resin composition is 200 to 400 μN / cm and the visible light transmittance at a wavelength of 600 nm is 10% or more. This is probably because the fluororesin produces a transfer film on the counterpart material and the transfer film has high lipophilicity.

(Abrasion test)
Further, the surface roughness in the direction perpendicular to the moving direction was measured at both ends and the center of the sliding portion of the aluminum alloy AC8A plate coated with the resin composition after the end of 18000 cycles, and the wear depth of the resin composition was measured. Asked. Table 1 shows the measurement results of the wear depth after the friction test.

From Table 1, about Example 1 and 2, abrasion of a resin composition is suppressed rather than the comparative example 3 by adding the graphite whose Mohs hardness is 1-2.
In particular, since the polyether ether ketone resin was further contained in Example 2, it was possible to improve wear resistance while reducing friction as compared with Example 1.

  On the other hand, in Comparative Example 1, since general polytetrafluoroethylene was contained, the tetrafluoroethylene-containing portion was selectively worn even though graphite was contained, resulting in wear of the entire resin composition. It is considered that the wear depth was increased as compared with Examples 1 and 2.

  Moreover, about Comparative Example 2, although the abrasion loss of resin composition itself was suppressed, the vertical crack generate | occur | produced in the vertex part of the cylindrical test piece made from FCA.

It is explanatory drawing which shows the outline | summary of a friction test. It is a graph which shows a time-dependent change of a static friction coefficient. It is a graph which shows a time-dependent change of a dynamic friction coefficient.

Explanation of symbols

1 plate 10 slide table 20 cylindrical specimen

Claims (15)

Included in the coating formed on at least part of the sliding portion of the base material of the sliding member that slides in the presence of the lubricant,
A resin composition comprising a base material resin, a fluororesin, and graphite,
The base material resin contains at least one selected from the group consisting of polyamide resin, polysulfone resin, polyetherimide resin, polyethersulfone resin, polyamideimide resin, polyimide resin, polyetheretherketone resin and epoxy resin. ,
The fluororesin has a surface energy of 200 to 400 μN / cm of the fluororesin, and a visible light transmittance of 10% or more at a wavelength of 600 nm of the fluororesin,
The content of the fluororesin is 10 to 30% based on the total amount of the resin composition,
The graphite is characterized in that the graphite has a Mohs hardness of 1 to 2. 2. The resin composition according to claim 1, wherein the base material resin comprises a polyamide-imide resin and a polyether ether ketone resin. The resin composition according to claim 1 or 2 , wherein the fluororesin is fluororesin particles having an average particle diameter of 1 to 50 µm. The resin composition according to claim 1 or 2 , wherein the fluororesin is fluororesin particles having an average particle diameter of 1 to 30 µm. The resin composition according to any one of claims 1 to 4, wherein the graphite is graphite particles having an average particle diameter of 1 to 30 µm. The resin composition according to any one of claims 1 to 4, wherein the graphite is graphite particles having an average particle diameter of 1 to 10 µm. The resin composition according to any one of claims 1 to 6, wherein the graphite is scaly graphite particles. The resin composition according to any one of claims 1 to 7 , wherein the graphite content is 2 to 40% based on the total amount of the resin composition. The resin composition according to any one of claims 1 to 7 , wherein a content of the graphite is 2 to 10% based on the total amount of the resin composition. The base metal resin contains at least a polyamideimide resin, and the polyamideimide resin is derived from a material obtained by firing a polyamideimide resin material having a number average molecular weight of 1000 to 10,000 . The resin composition according to any one of items 9 to 9 . Sliding member characterized by the application to formed Turkey resin composition according to any one of claims 1 to 10. The sliding member according to claim 11 , wherein a thickness of the coating formed by applying the resin composition is 2 to 70 μm. The sliding member according to claim 11 or 12 , wherein the surface roughness of the sliding portion of the coating is 15 µm or less in terms of the maximum surface roughness Rz. Sliding device comprising a benzalkonium comprises a sliding member according to any one of claims 11 to 13. An automobile piston, wherein the sliding member according to any one of claims 11 to 13 is applied to a piston skirt portion.

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