JP2015040216A - Slide member and bearing using the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a slide member capable of enhancing initial affinity at an early stage during sliding.SOLUTION: A slide member has a lubricating film 10 coated on the surface of a base material 11 and consisting of a first film 12 coated on the surface of the base material 11 and a second film 15 coated on the surface of the first film 12. The first film 12 consists of a solid lubricant 13 and a bonding resin for bonding the solid lubricant 13. The second film 15 consists of porous particles 16 chemically bonded by a fluorine based organic material 16a so as to coat the surface of the porous particle and the inner surface of a hole 16b, and a bonding resin 17 for bonding the porous particles.

Description

  The present invention relates to a sliding member whose surface is coated with a resin film and a bearing using the sliding member.

  2. Description of the Related Art Conventionally, a method of forming a lubricating coating has been adopted as one means for improving wear resistance or seizure resistance on the surface of sliding parts such as engines of internal combustion engines. As means for improving the sliding characteristics of the lubricating coating, a sliding member has been proposed in which a lubricating coating in which a solid lubricant is blended with a resin serving as a binder is coated.

  For example, Patent Document 1 proposes a sliding member in which a lubricating coating composed of a first coating coated on the surface of a substrate and a second coating coated on the surface of the first coating is formed. . Here, the first coating is composed of a solid lubricant composed of polytetrafluoroethylene and molybdenum disulfide and a binding resin that binds the solid lubricant, and the second coating is composed of a solid lubricant composed of boron nitride and nitriding It consists of hard particles made of silicon and alumina and a binding resin that binds them.

JP 2008-056750 A

  However, when the lubricating film as in Patent Document 1 is provided on the sliding member, the second film in which the sliding surface that slides in the initial sliding stage is formed is bonded to the hard particles and the solid lubricant by the binding resin. The coated film. For this reason, the second coating is hard to wear at the initial stage of sliding, and this is particularly noticeable when the load is low (when the low surface pressure is applied). As a result, familiarity cannot be obtained early in the initial stage, and it may take time to obtain a good sliding surface.

  The present invention has been made in view of such points, and an object of the present invention is to provide a sliding member that can enhance initial familiarity at an early stage during sliding.

  In view of the above problems, the sliding member according to the present invention is a sliding member in which a surface of a base material is coated with a lubricating film, and the lubricating film is a first film in which the surface of the base material is coated. And a second coating coated on the surface of the first coating, wherein the first coating comprises a solid lubricant and a binding resin that binds the solid lubricant, and the second coating comprises: It is characterized by comprising porous particles in which a fluorine-based organic material is chemically bonded so as to cover the surface and the inner surface of the pores, and a binding resin for bonding the porous particles.

  According to the present invention, since the fluorinated organic material covers the surface of the porous particles and the inner surface of the pores in the second coating, the surface of the second coating has oil repellency. Furthermore, even if the porous particles begin to wear, the surface of the second coating film has oil repellency because it contains a fluorine-based organic substance. As a result, an oil film is not easily formed on the second coating during sliding, and the second coating is likely to wear because it is easy to directly contact the sliding member and the mating member.

  At the initial familiarization stage, a part of the second film remains, a part of the first film as a base is exposed, and an oil film is hardly formed on a part of the first film due to the oil repellency of the second film. Since the first coating contains a solid lubricant, it is possible to suppress wear while improving the conformability of the surface of the first coating. As a result, a good sliding surface is formed on the first coating. In this way, the initial familiarity can be increased early when the sliding member slides.

  In a more preferred embodiment, the porous particles are contained in an amount of 30% by mass or more with respect to the second coating. According to the present invention, the oil repellency of the surface of the second coating can be stably maintained by containing the porous particles in the above-described proportion in the second coating. Here, when the porous particles are contained in a proportion of less than 30% by mass, the oil repellency of the second coating may be increased. In order to bind the porous particles to each other with the binding resin, the porous particles are preferably contained at 50% by mass or less.

  Furthermore, as a preferable aspect, the pore diameter of the porous particles is 4 to 100 nm. According to this aspect, by setting the pore diameter of the porous particles in the above-described range, the oil repellency of the second coating can be ensured not only at room temperature but also at a high temperature (a temperature of about 80 ° C.). When the pore diameter exceeds 100 nm, the pore diameter is too large, so that the proportion of the air layer in the pore becomes too large, and the oil repellency effect may not be obtained. Similarly, when the pore diameter is smaller than 4 nm, sufficient air repellency cannot be obtained because there is almost no air layer.

  Furthermore, as a preferable aspect, the binding resin contained in the first coating and the second coating is the same type of binding resin. According to this aspect, adhesiveness can be improved at the interface between the first film and the second film by using the same type of resin as the binding resin contained in the first film and the second film.

  As a more preferable aspect in the case of suitably applying such a sliding member, the sliding member is a bearing and is at least one of an inner race or an outer race of the bearing. Since the sliding surfaces of the inner race and the outer race of the bearing generally have a lower surface pressure than that of mechanical parts, the initial familiarity of the lubricating coating described above can be expressed at an early stage.

  According to the present invention, initial familiarity can be increased at an early stage during sliding.

The typical conceptual diagram of the sliding member which concerns on this embodiment of this invention. The expanded sectional view of the sliding surface of the sliding member shown in FIG. Schematic conceptual diagram of an abrasion characteristic / seizure characteristic evaluation tester. The typical conceptual diagram of an abrasion characteristic evaluation test machine. The figure which showed the relationship between the particle size of the particle | grains which concern on the confirmation tests 1-7, and a contact angle. The figure which showed the relationship between the particle size of the particle | grains and sliding angle which concern on the confirmation tests 1-7. The figure which showed the relationship between the pore diameter of the particle | grains which concern on the confirmation tests 8-12, and a contact angle. The figure which showed the relationship between the pore diameter and sliding angle of the particle | grains concerning the confirmation tests 8-12. The figure which showed the friction coefficient of the sliding member which concerns on Examples 1-4 and Comparative Examples 1 and 2. FIG. The figure which showed the baking surface pressure of the sliding member which concerns on Examples 1-4 and Comparative Examples 1 and 2. FIG. The figure which showed the abrasion loss of the sliding member which concerns on Examples 1-4 and Comparative Examples 1 and 2. FIG. The figure which showed the change of the friction coefficient with the time passage in the high surface pressure of the sliding member which concerns on Examples 1-4 and Comparative Examples 1 and 2. FIG. The figure which showed the change of the friction coefficient with the time passage in the low surface pressure of the sliding member which concerns on Examples 1-4 and Comparative Examples 1 and 2. FIG. The figure which showed the change of the friction coefficient with the time passage in the low surface pressure of the sliding member which concerns on Example 1 and Comparative Examples 1 and 3. FIG. The figure which showed the change of the friction coefficient with time passage in the low surface pressure of the sliding member which concerns on Example 5 and Comparative Example 4. FIG. The figure which showed the result of the sliding angle of the sliding member which concerns on Examples 6-10 and Comparative Examples 5-7.

Hereinafter, the present invention will be described based on the present embodiment with reference to the drawings.
FIG. 1 is a schematic conceptual view of a sliding member according to this embodiment of the present invention, and FIG. 2 is an enlarged sectional view of a sliding surface of the sliding member shown in FIG.

  As shown in FIG. 1, the sliding member 1 according to the present embodiment has a lubricating coating 10 coated on the surface of a base material 11. The lubricating coating 10 is composed of a first coating 12 coated on the surface of the substrate 11 and a second coating 15 coated on the surface of the first coating 12.

  The first coating 12 includes a solid lubricant 13 and a binding resin 14 that binds the solid lubricant 13. As shown in FIGS. 1 and 2, the second coating 15 includes a porous particle 16 in which a fluorine-based organic material 16a is chemically bonded so as to cover the surface and the inner surface of the pore (pore) 16b, and a porous particle. And a binding resin 17 for binding 16.

  Here, the base material 11 may be not only a metal material such as iron and aluminum, but also a ceramic material such as alumina, and is particularly limited as long as the material has higher hardness and strength than a lubricating coating described later. It is not a thing.

  The bonding resin (matrix resin) 14 for bonding the solid lubricants 13 of the first coating 12 and the bonding resin (matrix resin) 17 for bonding the porous particles of the second coating 15 are 100 ° C. or higher, preferably 150 ° C. It is desirable that the resin be thermally deformed. For example, a polyamideimide resin, a polyimide resin, a phenol resin, an epoxy resin, a urethane resin, and the like can be given.

  Here, in this embodiment, the binding resin included in the first coating 12 and the second coating 15 is the same type of binding resin. Thus, the adhesiveness of the 1st coating film 12 and the 2nd coating film 15 can be improved by making the binding resin contained in the 1st coating film 12 and the 2nd coating film 15 into the same kind of binding resin.

  Examples of the solid lubricant 13 included in the first coating 12 include molybdenum disulfide, PTFE, and graphite. Examples of the porous particles 16 included in the second coating 15 include porous particles such as silica particles, alumina particles, titania particles, zirconia particles, niobium oxide particles, tungsten oxide particles, and zeolite particles.

  Examples of the fluorine-based organic substance 16a chemically bonded to the surface of the porous particles 16 and the pores (pores) 16b include fluoroalkylsilanes, and other examples include perfluoroalkylcarboxylic acid-based compounds, Perfluoroalkyl sulfonic acid-based, perfluoroalkyl phosphoric acid-based surface treatment agents, perfluoroalkyl group-containing oligomers, various fluororesins represented by PTFE, fluorinated graphite, fluorinated pitch, and the like may be used.

  Here, the fluorinated organic material 16a is chemically bonded to the surface of the porous particles 16 and the inner surfaces of the pores (pores) 16 in the form of a monomolecular film. As a result, the state of the pores can be maintained without blocking the pores of the porous particles 16, and as shown in FIG. It has become. As a result, the contact angle of the surface of the second coating 15 can be increased and the sliding angle can be reduced by the holes (air layer) formed on the surface of the porous particles 16, and the wear of the second coating 15 can be reduced. Even when the oil proceeds, oil repellency can be maintained.

  The pore diameter of the porous particles coated with such a fluorine-based organic material is preferably 4 to 100 nm, and the porous particles preferably contain 30% by mass or more with respect to the second coating. . In addition, the reason for this preferable pore diameter and content (addition amount) will be described in Examples described later.

  Such porous particles 16 are produced, for example, by a sol-gel method. For example, when silica particles are synthesized by the same method, an alkoxide such as TEOS (tetraethyl orthosilicate) is acidic or basic. It can be obtained by dehydrating and synthesizing alcohol by hydrolysis / polycondensation reaction, and then separating and drying / calcining components other than silica including alcohol. The pore diameter of the porous particles can be changed by changing the mixing ratio or the like.

Then, the surface of the obtained porous particles 16 and the inner surfaces of the pores (pores) 16b are coated with the fluorinated organic material 16a using a surface graft method, a wet method, a sputtering method, or the like. For example, in the case of the surface graft method, first, the porous particles 16 are uniformly irradiated with ultraviolet rays in a low vacuum dry nitrogen atmosphere to activate the surfaces of the porous particles 16 and the inner surfaces of the pores (pores) 16b. Next, the inside of the glove box is filled with a nitrogen atmosphere, and the fluorine-based organic substance (for example, fluoroalkylsilane, a typical chemical structure is CF ₃ (CF ₂ ) ₅ CH ₂ CH ₂ Si (OCH ₃ ) that becomes the porous particles 16 and the reagent. ₃ ), etc., manufactured by Tokyo Chemical Industry Co., Ltd. (T1770, T2577, T2705, etc.) are enclosed in a pressure vessel, and the pressure vessel is placed in an oven for chemical vapor adsorption. In this way, the surface of the porous particles 16 and the inner surface of the pores (pores) 16b are coated with the fluorinated organic material 16a without closing (filling) the pores (pores) 16b of the porous particles 16. Can do.

  Then, when the first coating 12 and the second coating 15 are coated, the above-described binding resin (matrix resin) is dissolved in an organic solvent, a solid lubricant 13 is added to the first coating 12, and the second coating is added. Porous particles 16 are added to the coating 15. For example, when a polyamide-imide resin is used as the binding resin, N-methyl-2-pyrrolidone (NMP), N-ethylpyrrolidone (NEP), 1,3-dimethyl-2-imidazolidinone (DMI) is used as the organic solvent. ), Γ-butyl lactone (GBL) and the like. Moreover, when using an epoxy resin, methyl ethyl ketone (MEK) and toluene can be used. Then, these solutions are sequentially applied and baked to form the first coating 12 and the second coating 15 in sequence.

  The sliding member 1 thus obtained can be expected to have the following effects. First, since the fluorinated organic material 16a covers the surface of the porous particles 16 and the inner surfaces of the holes 16b in the second coating 15, the surface of the second coating 15 has oil repellency.

  Furthermore, even if the porous particles 16 start to wear, the surface of the second coating 15 has oil repellency because it contains the fluorine-based organic matter 16a. Thereby, the oil film 50 is not easily formed on the surface of the second coating 15 during sliding, and the second coating 15 is easily worn because it directly contacts the sliding member 1 and the mating member.

  At the initial familiarization stage, a part of the second film 15 remains, a part of the first film 12 serving as the base is exposed, and an oil film is formed on a part of the first film 12 due to the oil repellency of the second film 15. However, since the first coating 12 contains a solid lubricant, it is possible to suppress wear while improving the conformability of the surface of the first coating 12. As a result, a good sliding surface is formed on the first coating 12. In this way, the initial familiarity can be increased early when the sliding member 1 slides.

The following examples illustrate the invention.
<Confirmation tests 1-7>
First, in the confirmation tests 1 to 7, non-porous silica particles were used, and an oil repellency confirmation test was performed without using a binder resin serving as a binder. The surface of the nonporous silica particles was coated with fluoroalkylsilane CF ₃ (CF ₂ ) CH ₂ CH ₂ Si (CH ₃ ) ₃ as a fluorine-based organic material to prepare a test piece. Fluoroalkylsilane was bonded to each fine particle by a surface graft method. First, the fluoroalkylsilane silica fine particles were uniformly irradiated with ultraviolet rays for 10 minutes in a low vacuum of 2000 Pa and a dry nitrogen atmosphere. Next, the inside of the glove box was filled with a nitrogen atmosphere, the above-mentioned nonporous silica fine particles and fluoroalkylsilane were sealed in a pressure vessel, and the pressure vessel was placed in an oven at 180 ° C. for 90 minutes for chemical vapor adsorption. In confirmation tests 1 to 7, nonporous silica particles having an average particle diameter shown in Table 1 were used.

  The particle size of the nonporous silica particles was measured using SALD-7100 (manufactured by Shimadzu Corporation). The measurement principle is that a laser beam emitted from a light source is converted into a slightly thick beam by a collimator and irradiated to a group of nonporous silica particles. Forward scattered light emitted from the particle group up to a wide angle of 60 ° is collected by a lens, and a diffraction / scattered image is detected by a light receiving element located at a focal length. The light intensity data in all directions detected in this way became the light intensity distribution data, and the particle size distribution was calculated based on this data.

<Contact angle test>
The contact angles with respect to the engine oil at 25 ° C. and 80 ° C. were measured for the test pieces according to confirmation tests 1 to 7, respectively. A contact angle measuring device (LSE-B100, manufactured by Asumi Giken Co., Ltd.) includes a droplet dropping device for dropping a droplet on a solid substrate, a CCD camera, a capturing device for capturing a droplet image thereby, and a captured droplet The image analyzing apparatus calculates the contact angle with respect to the test piece from the contour of the image.

  As a droplet dropping device, a 1.0 ml syringe was used, and about 0.1 ml of a droplet (using engine oil) was formed on the test piece. The droplet outline was read as coordinates from the droplet image captured by the CCD camera into the computer using commercially available image analysis software. The contact angle was calculated from the shape of the read droplet using an image analyzer according to the Laplace equation. The result is shown in FIG.

<Sliding angle test>
The sliding angle with respect to the engine oil of 25 degreeC and 80 degreeC was measured with respect to the test piece which concerns on the confirmation tests 1-7. The apparatus configuration is the same as the contact angle measuring apparatus described above, and an apparatus capable of inclining a solid substrate (test piece) with a resolution of 0.1 ° is used as the dropping apparatus.

  As a droplet dropping device, a 5.0 ml syringe was used, and about 1.0 ml of a droplet (using engine oil) was formed on the test piece. Thereafter, the angle of the test piece is gradually increased at intervals of 0.5 °, and the image of the droplet is taken into the computer by the CCD camera. And the angle when a droplet moved 1 mm was measured as a sliding angle. The result is shown in FIG.

  As shown in FIG. 5, all the test pieces maintain a contact angle of 115 ° to 120 ° with respect to the engine oil. However, at an oil temperature of 80 ° C., which is an actual working temperature region, the contact angle is 1 μm or more. It can be seen that the oil repellency is gradually lowered.

  Furthermore, as shown in FIG. 6, at a room temperature, if the particle diameter is 1 μm or less, the sliding angle is maintained at about 10 ° C. However, in order to maintain oil repellency at an oil temperature of 80 ° C., the particle diameter It can be said that 10-50 nm which is the range of the test piece of the confirmation tests 1 and 2 is preferable. This is considered to be because fine irregularities are formed on the surface by using particles having a particle diameter of 10 to 50 nm, and the oil repellency is more exhibited even at high temperatures. As the particle size increases, the volume of the air layer formed between the particles increases, and the oil repellency is considered to decrease due to a decrease in oil viscosity and a decrease in surface tension accompanying an increase in temperature.

<Confirmation test 8-12>
First, in the confirmation tests 8 to 12, an oil repellency confirmation test was performed using porous (porous) silica particles without using a binder resin serving as a binder. In the confirmation tests 8 to 12, the pore diameter of the porous silica particles was set in the range shown in Table 2.

  The pore diameter of the porous silica particles was measured using, for example, Asap 2020 series (manufactured by Shimadzu Corporation). The measurement principle is to adsorb gas molecules having a known adsorption area on the surface of powder particles, and measure the specific surface area and pore distribution of the sample from the amount (gas adsorption method).

  The surface of the porous silica particles and the inner surfaces of the pores (pores) were coated with fluoroalkylsilane in the same manner as in the confirmation tests 1 to 7 to prepare test pieces. The test pieces for the confirmation tests 8 to 12 were subjected to the contact angle and sliding angle measurement tests in the same manner as for the confirmation tests 1 to 7. The results are shown in FIG. 7 and FIG.

  As shown in FIGS. 7 and 8, the oil repellency effect was exhibited by the effect of the pores despite the particle size being 5 μm. As shown in FIG. 7, even at 80 ° C., as in the confirmation tests 8 to 11, when the pore diameter is 4 to 100 nm, the contact angle range of 115 ° to 120 ° is maintained. Further, as shown in FIG. 8, the pore diameter is 4 to 100 nm as in the confirmation tests 8 to 11 and maintains a low value, and if the pore diameter is 10 to 50 nm as in the confirmation tests 9 and 10, it further slides down. The angle showed a low value.

  From the above, it is considered that the oil repellency of the second coating can be secured not only at room temperature but also at a high temperature (temperature of about 80 ° C.) by setting the pore diameter of the porous particles to 4 to 100 nm. It is done. When the pore diameter exceeds 100 nm, the pore diameter is too large, so that the ratio of the air layer in the pores becomes too large, and it may be impossible to obtain an oil repellency effect. Similarly, when the pore diameter is smaller than 4 nm, it is considered that sufficient oil repellency cannot be obtained because there is almost no air layer.

<Examples 1-4>
In Examples 1 to 4, sliding members shown in Table 3 below were produced using the porous particles (oil-repellent particles) according to Confirmation Test 9. Specifically, a polyamideimide (PAI) resin was prepared as a binding resin for the first coating and the second coating. N-methyl-2pyrrolidone (NMP) was prepared as an organic solvent, and PAI was dissolved.

A solid lubricant (molybdenum disulfide (MoS ₂ ), graphite, PTFE) is added to the solution in which PAI is dissolved in the ratio shown in Table 3 below, and the mixture is kneaded for 1 hour using a kneader, and the viscosity at 20 ° C. is 10 A composition for the first film of ˜100 Pa · s was obtained.

  Porous particles coated with fluoroalkylsilane (particles prepared in Confirmation Test 9 (oil-repellent particles)) at a ratio shown in Table 3 below are added to the solution in which the PAI is dissolved, and 1 using a kneader. The composition for the 2nd film which knead | mixed for time and whose viscosity in 20 degreeC is 10-100 Pa.s was obtained.

  First, a first coating composition is screen-printed on an aluminum alloy substrate (base material) using a mesh size (# 100) screen, and pre-heated at 90 ° C. for 20 minutes to form a first coating. Filmed. Next, the composition for the second film is screen-printed on the first film using a mesh size (# 100) screen and baked at 180 ° C. for 90 minutes as preheating to volatilize the organic solvent. Thus, a sliding member coated with a lubricating coating having a thickness of 10 μm (second coating thickness: about 2 mm, first coating thickness: about 8 μm) was obtained.

<Comparative Examples 1-3>
A sliding member was produced in the same manner as in Example 1. Comparative Example 1 is different from Example 1 in that boron nitride particles are added to the second coating instead of oil-repellent particles. Comparative Example 2 is different from Example 1 in that boron nitride particles are added to the second coating instead of oil-repellent particles, and the addition amount of molybdenum disulfide (MoS ₂ ) in the first coating is further reduced. Instead, graphite is added. Comparative Example 3 is different from Example 1 in that porous silica particles are added to the second coating instead of oil-repellent particles (that is, fluoroalkylsilane CF ₃ (CF ₂ ) CH ₂ is added to the porous silica particles. (CH ₂ Si (CH ₃ ) ₃ not covered)).

(Evaluation test of friction characteristics and seizure characteristics)
As shown in FIG. 3, the sliding members 1 of Examples 1 to 4 and Comparative Examples 1 and 2 are pressed against the end face of a mating member (cylindrical test piece) 20 made of gray cast iron (FC230) to obtain friction characteristics and seizure. Characteristics were evaluated. Specifically, in engine oil (80 ° C.), after the leveling operation, the friction coefficient at a test surface pressure of 10 MPa when the test operation was stepped up was measured to evaluate the wear characteristics. Further, the test load is stepped up, and when the first coating of the sliding member 1 is worn or peeled off, the sliding member 1 and the mating member are in direct contact with each other, and the load at which the torque rapidly increases (seizing load) is measured. Baking evaluation was performed.

  FIG. 9 is a diagram showing the friction coefficients of the sliding members according to Examples 1 to 4 and Comparative Examples 1 and 2, and FIG. 10 is a sliding member according to Examples 1 to 4 and Comparative Examples 1 and 2. It is the figure which showed the printing surface pressure of no.

(Abrasion characteristics evaluation test)
As shown in FIG. 4, the sliding members 1 of Examples 1 to 4 and Comparative Examples 1 and 2 were pressed against the outer peripheral surface of a mating member (cylindrical test piece) 30 made of rotating gray cast iron (FC230) to wear. Characteristics were evaluated. Specifically, after wear-in in engine oil (80 ° C.), the wear depth of the lubricating coating after measuring a wear test for a fixed time (3 minutes) at a test load of 45 MPa is measured to determine the wear characteristics. Evaluated. FIG. 11 is a diagram showing the amount of wear of the sliding members according to Examples 1 to 4 and Comparative Examples 1 and 2.

(Evaluation test of initial familiarity characteristics)
Using the apparatus shown in FIG. Specifically, in engine oil (80 ° C.), after the running-in operation, the transition of the friction coefficient with a constant test load was evaluated. FIG. 12 is a diagram illustrating a change in the coefficient of friction with time in the high surface pressure of the sliding members according to Examples 1 to 4 and Comparative Examples 1 and 2. FIG. 13 is a diagram showing a change in the friction coefficient with the passage of time at a low surface pressure (1 MPa) of the sliding members according to Examples 1 to 4 and Comparative Examples 1 and 2. FIG. 14 is a diagram showing a change in the coefficient of friction with the passage of time at a low surface pressure (1 MPa) of the sliding members according to Example 1 and Comparative Examples 1 and 3.

[Result 1 and discussion 1]
As shown in FIG. 9, in the friction coefficient evaluation test, the friction coefficients of the sliding members of Examples 1 to 4 and Comparative Examples 1 and 2 were comparable. As shown in FIG. 10, in the seizure characteristics evaluation test, the seizure surface pressures of the sliding members of Examples 1 to 4 and Comparative Examples 1 and 2 were comparable. As shown in FIG. 11, in the wear characteristic evaluation test, the wear amounts of the sliding members of Examples 1 to 4 and Comparative Examples 1 and 2 were comparable. When the sliding surface after the test is confirmed, the second coating layer of each sliding member is worn away, the first coating remains, the result of the remaining first coating, the above-described evaluation result is It is thought that all the sliding members became the same level.

  As shown in FIG. 12, in the familiarity property evaluation test, the friction coefficient at the time of high surface pressure (5 MPa) of the sliding members of Examples 1 to 4 and Comparative Examples 1 and 2 was comparable. As shown in FIG. 2, the friction coefficient at the time of low surface pressure (1 MPa) in Examples 1 to 4 was lower than that in Comparative Example 1 or 2.

  This is because the sliding members of Examples 1 to 4 positively promote solid contact even under low surface pressure by imparting oil repellency to the second coating (that is, the upper coating), and the lubricating coating itself is used as the counterpart member. This is thought to be due to the fact that it was able to be worn so as to follow.

  Furthermore, as shown in FIG. 14, when the surface of the porous silica particles and the inner surface of the pores were not coated with a fluorine-based organic material (fluoroalkylsilane) as in Comparative Example 3, the familiar characteristics as in Example 1 were obtained. Is not obtained and is understood to be the same as in Comparative Example 1.

<Example 5>
A sliding member was produced in the same manner as in Example 1. Comparative Example 1 is different from Example 1 in that porous titania particles are used in place of the porous silica particles, and as in Example 1, the surface of the particles and the inner surface of the pores (pores) are fluoroalkyl. This is the point where a monomolecular film of silane is coated.

<Comparative Example 4>
A sliding member was produced in the same manner as in Example 5. The difference between Comparative Example 4 and Example 5 is that the surface of the porous titania particles and the inner surface of the pores were not coated with a monolayer of fluoroalkylsilane.

  The sliding member of Example 5 and Comparative Example 4 was subjected to the above-mentioned evaluation test of the initial familiarity characteristics. The result is shown in FIG. FIG. 15 is a diagram illustrating a change in the coefficient of friction with the passage of time at a low surface pressure (1 MPa) of the sliding member according to Example 5 and Comparative Example 4.

[Result 2 and discussion 2]
As shown in FIG. 15, the sliding member of Example 5 had higher initial familiarity than the sliding member of Comparative Example 4. Therefore, even when porous titania particles are used instead of the porous silica particles shown in Example 1, the surface of the porous titania particles and the inner surface of the pores are coated with a monolayer of fluoroalkylsilane. By doing so, it is considered that the initial familiarity can be improved.

<Examples 6 to 10>
A sliding member was produced in the same manner as in Example 1. Examples 6 to 10 differ from Example 1 in the amount of oil-repellent particles added. Note that Example 6 and Comparative Example 1 have the same conditions.

<Comparative Examples 5-7>
A sliding member was produced in the same manner as in Example 1. The difference between Comparative Examples 5 to 7 and Example 1 is the amount of oil-repellent particles added. In addition, the sliding member which concerns on Comparative Examples 5-7 is contained in the sliding member of this invention.

  The sliding angle test described above was performed on the sliding members of Examples 6 to 10 and Comparative Examples 5 to 7. The result is shown in FIG.

[Result 3 and discussion 3]
As shown in FIG. 16, the sliding members of Examples 6 to 10 had a sliding angle smaller than those of Comparative Examples 5 to 7, and were almost the same value. From this, it can be said that if the addition amount of the oil-repellent particles to be added is 30% by mass or more, the oil-repellent performance is stably expressed in the second coating.

  Although the embodiments of the present invention have been described in detail above, the present invention is not limited to the above-described embodiments, and various designs can be made without departing from the spirit of the present invention described in the claims. It can be changed.

1: Sliding member 10: Lubricating film 11: Base material 12: First film 13: Solid lubricant 14: Binding resin (matrix resin)
15: Second coating 16: Porous particles 16a: Fluorine-based organic matter 16b: Pore (pore)
17: Binding resin (matrix resin)
50: Oil film

Claims (5)

A sliding member having a lubricating coating coated on the surface of the substrate,
The lubricating coating consists of a first coating coated on the surface of the substrate and a second coating coated on the surface of the first coating,
The first coating consists of a solid lubricant and a binding resin that binds the solid lubricant,
The second coating is composed of a porous particle in which a fluorine-based organic material is chemically bonded so as to cover the surface and the inner surface of the hole, and a binding resin that bonds the porous particle. Element.   The sliding member according to claim 1, wherein the porous particles are contained in an amount of 30% by mass or more with respect to the second coating.   The sliding member according to claim 1 or 2, wherein the pore diameter of the porous particles is 4 to 100 nm.   The sliding member according to any one of claims 1 to 3, wherein the binding resin contained in the first coating and the second coating is the same type of binding resin. A bearing comprising the sliding member according to any one of claims 1 to 4,
The bearing is characterized in that the sliding member is at least one of an inner race or an outer race of the bearing.

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