JP2014046673A - Slide member - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a slide member including a base material and a fluororesin layer provided in close contact with a surface of the base material, excellent in adhesiveness between the base material and the fluororesin layer and wear resistance, advantageous even in manufacturing costs and having no problem on slidability.SOLUTION: A slide member includes: a base material having a maximum height Ry of surface roughness of 20 μm or less; and a fluororesin layer provided on a surface of the base material and formed of a fluororesin crosslinked or includes: a base material having a surface etched and a fluororesin layer provided on a surface of the base material and formed of a fluororesin crosslinked.

Description

  The present invention includes a sliding member having a base material and a sliding portion made of a fluororesin layer provided in close contact with the surface thereof, and having excellent adhesion and wear resistance between the base material and the fluororesin layer. About.

  In the industrial field, the medical field, and the like, a sliding member formed by forming a sliding part on a base material made of metal or the like is widely used. The sliding portion is required to have wear resistance, heat resistance, chemical resistance, etc. as well as low friction properties (properties with low friction coefficient, sliding properties). Fluorocarbon resin is expected to be used as a material for forming a sliding portion because it is excellent in low friction, chemically extremely stable, and excellent in heat resistance and chemical resistance.

  However, there is a problem that fluororesins have low wear resistance. Therefore, Patent Document 1 proposes a method for improving wear resistance by irradiating ionizing radiation to a fluororesin, and discloses a sliding member having a fluororesin layer irradiated with ionizing radiation. There is also a problem that the fluororesin has low adhesion to the substrate. Therefore, in Patent Document 2, the surface of the base material is coated with a fluororesin and then irradiated with ionizing radiation, thereby causing a cross-linking reaction of the fluororesin and a chemical reaction between the fluororesin and the surface of the base material at the same time. A method for achieving good adhesion is disclosed.

  A method of increasing the adhesive force between the base material and the fluororesin layer by performing blasting on the base material to roughen the surface thereof is also widely performed. However, when fluororesin is coated on the surface of the blasted substrate, it is difficult to control the unevenness with blasting. Is exposed. In particular, in the case where the fluororesin is polytetrafluoroethylene (PTFE), cracks occur when the film thickness is increased, so that the entire film cannot be made thicker than a certain value, and this problem becomes remarkable. In a sliding member having a thin fluororesin layer on the convex part of the base material, the thin part preferentially comes into contact with the sliding counterpart material, so the sliding counterpart material reaches the base material and slides at an early stage after the start of sliding. Mobility is impaired.

  In order to solve such problems and achieve high adhesive strength and excellent slidability between the base material and the fluororesin, Patent Document 3 is familiar with bronze and lead such as copper plating on the base material. A method has been proposed in which good plating is applied, bronze powder or lead powder is spread and semi-melted thereon, and a fluororesin is applied thereon and baked. In the sliding member by this method, both excellent adhesiveness and slidability with the base material are achieved by bronze or lead powder.

Japanese Patent No. 3666805 JP 2002-225204 A Japanese Patent No. 3357561

  The dynamic friction coefficient of bronze and lead is lower than that of general aluminum, iron, and SUS as a base material, but is much higher than that of a film made of a single fluororesin such as PTFE. Moreover, bronze and lead have a problem of damaging and wearing the counterpart material. Therefore, the sliding member disclosed in Patent Document 3 has a problem in slidability. Further, the method of Patent Document 3 is disadvantageous in terms of manufacturing cost because the sliding member is manufactured through a complicated process.

  The present invention is a sliding member having a base material and a fluororesin layer provided in close contact with the surface thereof, and is excellent in adhesion and wear resistance between the base material and the fluororesin layer, and also in terms of production cost. It is an object of the present invention to provide a sliding member that is advantageous and has no problem with slidability.

  As a result of intensive studies to achieve the above-mentioned problems, the present inventor has provided a fluorine resin layer that is closely and cross-linked on a substrate having a maximum surface roughness Ry of 20 μm or less, or By providing an intimately cross-linked fluororesin layer on the surface of the etched base material, high adhesion between the base material and the fluororesin layer can be obtained, and the wear resistance is excellent. The present inventors have found that a sliding member that can be manufactured, is advantageous in terms of manufacturing cost, and does not have a problem of slidability can be obtained.

  The invention according to claim 1 (hereinafter sometimes referred to as the first invention) includes a base material having a maximum height Ry of 20 μm or less, and a fluororesin layer provided on the surface thereof, The sliding member is characterized in that the fluororesin constituting the fluororesin layer is crosslinked. Here, the sliding member refers to a member having a sliding surface having wear resistance and used for a sliding portion. Specifically, having wear resistance means that the result of a later-described thrust wear test (ring-on-disk wear evaluation, conforming to JIS K-7218) is 0.8 MPa or more. Note that 0.8 MPa corresponds to the wear resistance of the ultrahigh molecular weight polyethylene sheet that is frequently used as a sliding material.

  This invention is characterized in that the maximum height Ry of the surface roughness of the substrate is 20 μm or less. The maximum height Ry is a value representing the maximum height of the surface roughness of the substrate, and is a measurement value defined in JIS B 0601-1994. Since the maximum height Ry is 20 μm or less, the surface of the substrate is smooth and is not subjected to roughening treatment such as blasting. The maximum height Ry is preferably 10 μm or less.

  Further, the present invention is characterized in that a fluororesin layer is provided in close contact with a base material made of metal or the like, and the fluororesin forming the fluororesin layer is crosslinked. A fluororesin layer formed from a cross-linked fluororesin can be formed by coating a fluororesin on a substrate to form a fluororesin layer, and then irradiating with ionizing radiation to crosslink the fluororesin. . By performing crosslinking after the formation of the fluororesin layer, the adhesive force between the base material and the fluororesin layer can be ensured.

  Further, excellent wear resistance can be obtained by crosslinking the fluororesin. It is also suitable as a sliding member in that the abrasion resistance of the fluororesin is improved by crosslinking. When the fluororesin is not crosslinked, the wear resistance is insufficient and the usefulness as a sliding member is lowered.

  Furthermore, the sliding member of the present invention is excellent in slidability (low friction coefficient) and chemical resistance because the sliding portion is made of a fluororesin. In the sliding member of the present invention, since the surfaces of both the base material and the fluororesin layer are smooth, the problem caused by the blasted sliding member or the sliding member described in Patent Document 3, that is, the base material It is possible to stably maintain excellent slidability without causing a problem that the slidability is easily impaired at the convex portion.

  The sliding member of the present invention can be produced by a method in which a fluororesin layer is formed in close contact with the surface of a substrate and the fluororesin is crosslinked by irradiation with ionizing radiation. Other processes such as a plating process and semi-melting in the method described in Patent Document 3 are unnecessary. Therefore, the process is simple, the production is easy, and the production cost is advantageous.

  The invention according to claim 2 (hereinafter sometimes referred to as the second invention) has a base material and a fluororesin layer provided on the surface thereof, and the base material surface is subjected to an etching treatment, And the fluororesin which comprises the said fluororesin layer is bridge | crosslinked, It is a sliding member characterized by the above-mentioned.

  The sliding member of the present invention is characterized in that the surface of the base material is etched. The etching process means a plastic forming or surface processing method using a corrosive action such as a chemical (corrosive liquid, etching liquid). It also includes electric field etching in which surface processing is performed while energizing using an electrolytic solution as an etching solution. For example, when the substrate is made of aluminum, the surface of the substrate can be etched by electric field etching as described in JP-B-59-12759.

  In the etching treatment, impurities on the surface of the base material can be selectively dissolved to form a concave shape (fine concave portion) having a diameter of several tens to several hundreds of μm on the surface of the base material. When the fluororesin enters the fine recesses on the surface of the substrate, an anchor effect is generated and the adhesive strength can be increased. According to the etching process, there is no problem that occurs with the blasted sliding member or the sliding member described in Patent Document 3, that is, the problem that the slidability is easily impaired at the convex portion of the base material. Stable and excellent slidability can be maintained.

  Further, the second invention is characterized in that, as in the first invention, a fluororesin layer is provided in close contact with a base material made of metal or the like, and the fluororesin forming the fluororesin layer is crosslinked. To do. If the surface of the substrate is etched and the fluororesin is crosslinked, excellent adhesion between the substrate and the fluororesin layer can be obtained. Therefore, the sliding member of the present invention is excellent in adhesion between the base material and the fluororesin layer, and is excellent in combination with chemical adhesion by crosslinking of fluororesin and anchor effect (physical adhesion) by etching treatment. Adhesion is obtained.

  The invention according to claim 3 is the sliding member according to claim 1 or 2, wherein the load length ratio tp is 80% or less. The load length ratio tp indicates the ratio between the flat portion and the concave portion of the plate (base material or the like), and can be measured according to JIS B 0601-1994. For example, theoretically, in the case of a flat plate without a concave portion, the load length ratio tp is 100%, and the surface is connected with a curved valley and has no flat portion like a blasted plate. In the case of a plate, it is 0%.

  The degree of etching treatment (etching index) can be expressed using the load length ratio tp. In the case of a plate that has been subjected to etching treatment, the lower the load length ratio tp, the fewer the flat portions and the greater the number of recesses, so that more anchor effect can be obtained and the adhesive strength can be enhanced. The preferable range of the load length ratio tp varies depending on the application, but when the load length ratio tp is 80% or less, the effect of strengthening the adhesive force can be exhibited. If it is 60% or less, since the effect is exhibited more clearly, it is preferable.

  Similar to the first invention, the second invention also has a significantly improved wear resistance due to the cross-linking of the fluororesin, which makes it suitable as a sliding member. Further, since the sliding portion is formed of a fluororesin, the sliding member is excellent in slidability (low coefficient of friction) and chemical resistance.

  The sliding member of the present invention can be produced by etching the surface of the base material, forming a fluororesin layer in close contact with the surface, and then crosslinking the fluororesin by irradiation with ionizing radiation or the like. Other processes such as a plating process and semi-melting in the method described in Patent Document 3 are unnecessary. Therefore, the process is simple, the production is easy, and the production cost is advantageous.

  The invention according to claim 4 is characterized in that the adhesive strength between the base material and the fluororesin layer is 90/100 or more by a cross-cut test, and the slide according to any one of claims 1 to 3 is characterized. It is a moving member.

  Here, the cross cut test is a test method described in JIS-K-5400 (1998 version), and specifically, 100 cross cuts are made on the fluororesin layer (surface layer). This is a test method in which a test is performed to peel off the tape after the tape has been applied thereon, and the number of grids remaining without being peeled off is counted. 90/100 or more means that 90 or more of 100 grids remain without being peeled after 100 times of the above peeling.

  Both the first invention and the second invention are sliding members excellent in the adhesive strength between the base material and the fluororesin layer, and those having an adhesive strength by a cross-cut test of 90/100 or more are particularly preferable. Here, the adhesive force is an initial adhesive force before use of the sliding member, that is, an adhesive force in a case where the sliding member has not been deteriorated due to use or the like.

  According to a fifth aspect of the present invention, the fluororesin forming the fluororesin layer is made of PTFE, tetrafluoroethylene / hexafluoropropylene copolymer (FEP), tetrafluoroethylene / perfluoroalkyl vinyl ether copolymer (PFA). The sliding member according to any one of claims 1 to 4, wherein the sliding member is selected from ethylene tetrafluoroethylene copolymer (ETFE) and polyvinylidene fluoride (PVdF).

  As the fluororesin, a tetrafluoroethylene-based polymer or a copolymer thereof can be used, and more specific examples include the above-described resins recited in claim 4. In addition, those using two or more kinds of fluororesins in combination and those composed of a resin composition to which a different component other than fluororesin is added are used within a range that does not impair the gist (adhesiveness, wear resistance, etc.) of the present invention. be able to. Examples of the different component include glass, carbon, metal, metal oxide, ceramics, heat resistant organic material, and mineral.

  A sixth aspect of the present invention is the sliding member according to any one of the first to fifth aspects, wherein the base material is formed of a metal or a radiator.

  Examples of the material for forming the base material include metals such as aluminum, iron, copper, and SUS, glass, resin, and the like, and an optimum material is selected according to the use of the sliding member. By using a base material having high thermal conductivity and excellent heat dissipation, it is possible to effectively conduct and remove the frictional heat generated during the use of the sliding member to the heat dissipator, thereby suppressing the temperature rise. . As a result, the wear resistance can be improved, which is preferable.

  The sliding member of the present invention is suitably used as a sliding member for semiconductor manufacturing equipment, a sliding member for medical equipment, an industrial machine, a consumer product, and the like.

  In the sliding member for semiconductor manufacturing equipment, PTFE and PFA are often used as fluororesin from the viewpoint of preventing chemical resistance and ion elution. Occurrence is a problem. However, since the sliding member of the present invention has high wear resistance, generation of wear powder can be significantly suppressed. In the sliding member of the present invention, the base material and the fluororesin layer are directly bonded with excellent adhesiveness, and no primer or the like is used. Therefore, it is preferable because there is no elution of ions and the like from various adhesive components contained in the primer, which has been a problem in conventional semiconductor manufacturing apparatuses.

  Examples of the sliding member for medical equipment include catheter piping. PTFE is frequently used as a fluororesin that constitutes a sliding member for medical devices because of its good body affinity. As in the case of semiconductor devices, the sliding members for medical equipment should not generate wear powder at the sliding parts or have any foreign substances eluted from the bonded parts with the base material made of metal such as SUS. Desired. However, since the sliding member of the present invention has high wear resistance even when the fluororesin is PTFE, generation of wear powder can be greatly suppressed, and adhesion to the substrate is direct and no primer is used. So there is no problem of elution of foreign matter. Therefore, the sliding member of the present invention is preferably used as a sliding member for medical equipment.

  The sliding member of the present invention has a low coefficient of friction similar to that of a conventional sliding member made of a fluororesin, and further has wear resistance superior to that of the conventional sliding member. It is suitably used for non-lubricated bearings used in products such as those requiring high wear resistance. Examples of the sliding member used in industrial machines and consumer products include various sliding bearings such as a winding bearing and a bush, a slider, and the like. Also, the sliding member of the present invention can be used in a portion that slides in a ring shape, such as a piston ring, piston skirt, suspension part, etc. used in an automobile or the like.

  Furthermore, the sliding member of the present invention can also be used for various guides, reels, rollers, trays, and the like through which metal wires such as packing, threads, electric wires and wires, and linear materials such as chains pass. It is preferable to use the sliding member of the present invention for a guide that receives a yarn that flows at a high speed, such as used in a spinning factory, because it can prevent the yarn from being damaged and suppress the settling of the guide.

  The sliding member of the present invention can also be used for deformed objects such as bearing retainers, gears, and scroll parts of compressors. In these cases, an effect such as oil-less operation can be expected, which is preferable.

  The sliding member of the present invention is excellent in adhesiveness and abrasion resistance between the base material and the fluororesin layer, is advantageous in terms of production cost, and has no problem of sliding property. Therefore, it can be suitably used as a sliding member for semiconductor manufacturing equipment and medical equipment and as a sliding member used in the industrial field.

It is a perspective view which shows notionally the thrust abrasion test (ring-on-disk type abrasion evaluation) performed by the Example and the comparative example.

  Next, the form for implementing this invention is demonstrated concretely. In addition, this invention is not limited to this form, It can change into another form, unless the meaning of this invention is impaired.

  The sliding member of the present invention can be manufactured, for example, as follows. First, a base material having a predetermined shape is formed, and surface treatment such as etching is performed as necessary. Thereafter, a fluororesin is coated on the surface, that is, the portion to be the sliding portion, to form a fluororesin layer. As a method of coating the fluororesin, a method of covering with a fluororesin film, a method of powder coating, a fluororesin dispersion (a liquid in which a fluororesin powder is uniformly dispersed in a dispersion medium) is applied and dispersed. Examples thereof include a method of removing the medium by drying. Examples of the powder coating method include a method of electrostatic coating of fluororesin powder and a method of spraying fluororesin powder.

  The method of applying the fluororesin dispersion is a preferable method in that a fluororesin layer having a uniform thickness can be easily formed. When the fluororesin is PTFE, a method of applying a fluororesin dispersion is usually employed. In the case of a fluororesin that is soluble in a solvent, a method of applying a fluororesin solution and drying and removing the solvent can also be adopted, but this method cannot be applied because PTFE is insoluble in a solvent.

  In the case of applying the fluororesin dispersion, water and an emulsifier, water and alcohol, water and acetone, or a mixed solvent of water, alcohol and acetone are used as the dispersion medium. After applying the fluororesin dispersion, the dispersion medium is dried and removed by air drying or hot air drying. A coating film made of fluororesin powder is formed by drying and removing the dispersion medium.

  After a coating film made of fluororesin powder is formed by powder coating, electrostatic coating, fluororesin dispersion coating, etc., firing is performed to a temperature higher than the melting point of the fluororesin, and the fluororesin powder is fused. A fluororesin layer is formed. Firing is preferably performed in a temperature range of 350 to 400 ° C. It is also possible to remove the dispersion medium in the firing step without providing a drying step.

  The thickness of the fluororesin layer is usually 1 μm to several hundred μm. Since industrial products always have manufacturing tolerances, if the thickness does not exceed the manufacturing tolerances, contact between the base material and the sliding counterpart material occurs depending on the piece. In order to prevent this problem, it is often preferable that the fluororesin layer of the sliding member is thick. However, when the fluororesin is PTFE, the fluororesin layer is formed by applying the dispersion. Therefore, the thickness is usually limited to about 10 μm, and even when using a special dispersion that enables thick coating, it is 30 μm. Is the limit. Therefore, when the fluororesin is PTFE, the thickness of the fluororesin layer is 1 to 30 μm, preferably 1 to 10 μm.

  Examples of the method for crosslinking the fluororesin include a method of irradiating ionizing radiation. The surface of the fluororesin layer formed as described above is irradiated with ionizing radiation to crosslink the fluororesin. When an appropriate combination of the fluororesin and the substrate is selected, the adhesion between the fluororesin layer and the substrate is also improved during this crosslinking.

  When crosslinking is performed by irradiation with ionizing radiation, a fluororesin layer is placed in an oxygen-free atmosphere, specifically in an atmosphere having an oxygen concentration of 100 ppm or less, preferably 5 ppm or less, and the crystal melting point of the fluororesin is about 400 ° C. It is preferable to irradiate the surface of the fluororesin layer with ionizing radiation while maintaining the temperature range, preferably a temperature range of 0 to 30 ° C. higher than the crystal melting point. If the temperature of the atmosphere is too low, the crosslinking reaction of the fluororesin is unlikely to occur, and if the atmosphere temperature is too high, especially when the temperature exceeds 400 ° C., thermal decomposition of the fluororesin is promoted and the material properties are deteriorated.

  The range of irradiation dose is generally 1 kGy to 1500 kGy, preferably 100 kGy to 1000 kGy. When the irradiation dose is less than 1 kGy, the crosslinking reaction is insufficient and improvement in characteristics cannot be expected, and when it exceeds 1500 kGy, the fluororesin is easily decomposed, which is not preferable. The formation of the fluororesin layer and the irradiation with ionizing radiation may be performed simultaneously.

  Examples of the ionizing radiation used for crosslinking the fluororesin include charged particle beams such as electron beams and high energy ion beams, high energy electromagnetic waves such as gamma rays and X rays, and neutron beams. The electron beam generator is relatively inexpensive and can produce a high-power electron beam and can easily control the degree of crosslinking. Therefore, an electron beam is preferable as the ionizing radiation.

  Materials having high thermal conductivity and excellent heat dissipation used as a base material include iron (thermal conductivity: 0.18 Cal / ° C. · cm · sec), SUS, aluminum (thermal conductivity: 0.53 Cal / ° C. · cm). (Second) etc. can be mentioned as preferable materials. Further, ceramic (brick) having a thermal conductivity of 0.07 Cal / ° C. · cm · sec can also be used. Furthermore, a filler for improving thermal conductivity is added to heat-resistant plastics such as polyimide, polyether ether ketone, and polyether sulfone having heat resistance that can withstand baking of a fluororesin (380 ° C., several tens of minutes). The one with higher thermal conductivity can also be used.

(1) Sample preparation As a substrate, a 3003 aluminum plate (thickness 1 mm) manufactured by Korea DAEHO was used, and any of the following surface treatments was performed.
Degreasing only (Indicated in Table 1 as “None” for substrate treatment)
Blasting: Sand blasting (Alumina No. 80 was used and performed at an air pressure of 0.5 MPa. In Table 1, “blasting” is shown.)
Etching: Electrolytic etching process (Ammonium chloride electrolyte was used and the amount of electricity was 23 C / cm ^{2. In} Table 1, “Etching” is shown.)

  On the surface of the base material prepared as described above, a fluororesin dispersion PTFE (EK-3700) manufactured by Daikin Co., Ltd. was applied, dried and baked at 380 ° C. to obtain a PTFE film having a thickness of 30 μm.

The PTFE membrane thus obtained was irradiated with an electron beam under the conditions shown below to crosslink the fluororesin to produce a sample. The obtained sample was measured for the initial adhesive strength, post-aging adhesive strength, substrate surface roughness Ra, Ry, Rz, and load length ratio tp by the following methods. These results are shown in Table 1.
[Conditions for electron beam irradiation]
Equipment used: Sagatron manufactured by Nissin Electric Co., Ltd. (acceleration voltage 1.13 MeV)
Oxygen concentration: 5 PPM, ambient temperature: 340 ° C.

[Measurement of initial adhesive strength]
The adhesive strength (peeling resistance) was evaluated by a cross-cut test defined in JIS-K5400 (1998 version). Specifically, 100 grids of scratches are made on the fluororesin layer, and tape is peeled off after being taped thereon (tape peeling) 100 times. The number of eyes was counted. For example, the notation 50/100 means that 50 of the 100 grids remain after 100 times of tape peeling.

[Measurement of adhesive strength after aging]
After immersing the sample in an oden solution made by Sasubi Co., Ltd. at 70 ° C. or higher for 1000 hours, the adhesive strength was measured in the same manner as the evaluation of the initial adhesive strength.

[Substrate surface roughness Ra, Ry, Rz, and load length ratio tp]
Measure surface roughness [Ra: arithmetic average roughness, Ry: maximum height, Rz: 10-point average roughness] specified by JIS B 0601-1994, using a surfcom manufactured by Tokyo Seimitsu Co., Ltd., at a measurement distance of 8 mm. Ra, Ry and Rz were obtained. Further, a load length ratio tp (%) was measured in accordance with JIS B 0601-1994 using a laser microscope VK-9510 manufactured by Keyence Corporation.

  As shown in the results in Table 1, when electron beam irradiation is not performed even after blasting (sample No. 3), the adhesive strength between the base material and the fluororesin layer is the stage before aging (initial adhesive strength). Low. On the other hand, when the electron beam irradiation was performed (sample No. 1, 2, 4) or when the etching process was performed without applying the electron beam irradiation (sample No. 5), the stage before the aging (initial adhesive strength) ) Shows excellent adhesive properties.

  Even at the stage after aging (adhesive strength after aging), when both electron beam irradiation and etching treatment to the base material were performed (sample No. 4), no peeling occurred and excellent characteristics were exhibited. However, when the electron beam irradiation was performed but the substrate surface treatment was not performed (Sample No. 1), when the electron beam irradiation and the blast treatment were both performed (Sample No. 2), the etching treatment was performed. In the case where the electron beam irradiation was not performed (sample No. 5), the adhesive force was lowered due to aging. 1 and sample no. The drop of 5 is large. That is, it has been shown that an excellent adhesive force can be obtained by performing both electron beam irradiation and etching treatment on the base material, and does not deteriorate even with aging.

  The sliding member used for cooking in a rice cooker used for cooking, semiconductor wafer trays used in acidic or alkaline solutions, coating on piston rings and piston skirts, etc. should have excellent adhesion even after aging desired. Therefore, it is preferable to perform both electron beam irradiation and etching treatment on the substrate. On the other hand, depending on the application of the sliding member, the adhesive force after aging may not be particularly necessary. For example, it is used for guides such as yarns and electric wires used in a dry state, reels, and rollers. Therefore, for these applications, the above sample No. 1, no. 2, no. 5 can also be used.

[Evaluation of wear resistance]
In accordance with JIS K-7218, the abrasion resistance of the fluororesin coating was evaluated by a thrust wear test (ring-on-disk wear evaluation). As shown in FIG. 1, the thrust wear test is a state in which a metal cylinder (mating shaft) is placed on a test sample and a predetermined load (pressure: P) is applied to the test sample at a predetermined speed (rotational speed). : V), and the wear state of the test sample is measured. Here, an S45C cylinder with an outer diameter / inner diameter = 11.5 / 7.4 is used as the mating shaft, wear is measured under dry (greaseless) lubrication conditions, and pressure is measured under a rotational speed (V) of 1,800 rpm. The pressure (MPa) at which rapid wear occurs by changing (P) was determined. The results are shown in Table 2. As comparative examples, polyacetal (POM), ultra high molecular weight polyethylene (ultra high molecular weight PE), polyphenylene sulfide (PPS), and polyether ether ketone (PEEK), which are commonly used as sliding materials, are used. A sheet was also prepared, and a thrust abrasion test was performed under the same conditions to obtain a pressure (MPa) at which rapid abrasion occurred. The results are shown in Table 3.

  As shown in the results of Tables 2 and 3, when the etching process was performed but the electron beam irradiation was not performed (Sample No. 5), the wear resistance is a material frequently used as a sliding material. It is much lower than POM, ultra high molecular weight PE, PPS, and PEEK, and is not preferable as a sliding member. This is because the fluororesin is not crosslinked. In the case where the surface treatment of the base material is not performed with the electron beam irradiation (sample No. 1) and the case where both the electron beam irradiation and the etching treatment to the base material are performed (sample No. 4), excellent wear resistance is obtained. Has been obtained. On the other hand, the wear resistance when both the electron beam irradiation and the blasting treatment on the base material (sample No. 2) are performed is as follows. 1, no. Inferior to 4. This is because the blast treatment is performed, and the sliding counterpart material and the base material come into contact with each other at the time of sliding due to the unevenness of the base material. From the results shown in Tables 1 and 2, it was determined that Sample No. 1 satisfied both the adhesive strength and the wear resistance after the aging test. It is shown that only 4. No. In No. 4, the adhesive force is remarkably enhanced by the combined use of etching and electron beam irradiation, and since there is no convex portion, there is almost no adverse effect of reducing the wear resistance.

Claims (6)

  A sliding member comprising a base material having a maximum height Ry of 20 μm or less and a fluororesin layer provided on the surface thereof, wherein the fluororesin constituting the fluororesin layer is crosslinked.   A slide having a base material and a fluororesin layer provided on the surface thereof, the surface of the base material being etched, and the fluororesin constituting the fluororesin layer being cross-linked Element.   The sliding member according to claim 1 or 2, wherein a load length ratio tp is 80% or less.   The sliding member according to any one of claims 1 to 3, wherein an adhesive force between the base material and the fluororesin layer by a cross-cut test is 90/100 or more.   The fluororesin forming the fluororesin layer may be polytetrafluoroethylene, tetrafluoroethylene / hexafluoropropylene copolymer, tetrafluoroethylene / perfluoroalkyl vinyl ether copolymer, ethylene / tetrafluoroethylene copolymer, and polytetrafluoroethylene copolymer. The sliding member according to any one of claims 1 to 4, wherein the sliding member is selected from vinylidene fluoride.   The sliding member according to any one of claims 1 to 5, wherein the base material is formed of a metal or a radiator.

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