JP5626715B2 - Sliding member and mechanical seal - Google Patents

Description

  The present invention relates to a sliding member suitable for use in a mechanical seal and the like, and a mechanical seal using the same. More specifically, the present invention relates to a sliding member that improves the adhesion between a substrate and a coating film and has excellent wear resistance. The present invention relates to a moving member, a manufacturing method thereof, and a mechanical seal using the same.

  The mechanical seal is a typical sealing device used for a shaft seal portion of various rotating machines. Specifically, the sliding member that rotates together with the rotating shaft and the sliding member provided on the fixed side that does not rotate slide closely against each other at the facing end faces, thereby preventing leakage of the sealed fluid. .

For example, in the case of a mechanical seal in which an atmosphere such as gas or mist is used under dry or semi-dry conditions, the lubricity of the seal liquid cannot be expected. Therefore, of the two materials facing each other (rotating side sliding member and fixed side sliding member), the soft side material is made of carbon material, graphite, glass fiber, carbon, etc. due to its characteristics such as self-lubrication and wear resistance. A tetrafluoroethylene resin (PTFE resin) -based material in which aggregates such as fibers are blended is generally used. On the other hand, silicon carbide (SiC), alumina (Al ₂ O ₃ ), cemented carbide (tungsten carbide), or the like is used as the material of the hard side member.

  However, the wear of the soft side member progresses with time, often reaches the end of its life in a short time, and the wear powder generated at the time of wear contaminates the sealing atmosphere. For this reason, there is a problem that its use is restricted when it is necessary to prevent contamination of foreign substances such as in the production process of foods and pharmaceuticals.

  In order to solve this problem, for the purpose of improving wear resistance, a sliding material in which a synthetic resin is coated on a metal material is also considered, but in this case, galling occurs when the coating is peeled off, There were problems such as greatly affecting the slidability.

  Patent Document 1 discloses that a coating containing a solid lubricating material is applied to the surface of a base material such as carbon as a sliding material. However, even if such a coating is applied to the surface of a brittle material such as carbon, for example, when it is immersed in hot water or exposed to a humid atmosphere for a long time, the adhesion to the substrate is poor. It is considered that the coating film can be peeled off. In addition, there is a limit to solve such a problem by improving the adhesion by adjusting the surface roughness of the substrate.

  Patent Document 2 discloses a sliding member obtained by impregnating a porous body with a resin composition. However, in such a sliding member, there are problems such as scratching due to the exposed convex portions of the porous body and abnormal occurrence of wear powder associated therewith during wear.

JP 2001-26792 A JP 2004-323789 A

  The present invention has been made in view of such a situation, and an object of the present invention is to provide a sliding member having good adhesion between a base material and a coating film and exhibiting excellent wear resistance, and a mechanical seal using the same. Is to provide. Another object of the present invention is to provide a method for producing a sliding member in which the base material and the coating film have good adhesion and exhibit excellent wear resistance.

In order to achieve the above object, the sliding member according to the present invention comprises:
A substrate comprising carbon having pores;
A coating film formed on the surface of the base material and containing a synthetic resin;
Part of the coating film is filled in the pores so as to be integrated with the coating film at the interface between the substrate and the coating film.

  In the present invention, the substrate contains carbon having pores, and a coating film containing a synthetic resin is formed on the surface thereof. At the interface between the substrate and the coating film, a part of the coating film is filled in carbon pores, and the coating film and a part of the coating film filled in the pores are integrated. In other words, the coating film is not only formed on the surface of the substrate, but part of the coating film is filled in the carbon pores, so that the coating film bites into the carbon, and between the substrate and the coating film. Then, a favorable anchor effect can be produced. As a result, it is possible to improve the adhesion between the substrate and the coating film that are usually difficult to adhere.

  Synthetic resins are inherently not suitable materials for sliding surfaces because they have thermal characteristics such as low thermal conductivity and high thermal expansion coefficient specific to the resin. However, since the above carbon has high thermal conductivity, even if heat is generated by friction on the sliding surface (coating film), it is easily radiated through the carbon. Therefore, the thermal characteristics such as low thermal conductivity and high thermal expansion coefficient of the synthetic resin are not particularly problematic.

  Preferably, the synthetic resin has a polyether ether ketone (PEEK) resin.

  When the synthetic resin has the PEEK resin, the coating film can be made excellent in wear resistance and corrosion resistance. Therefore, for example, by using a coating film containing PEEK resin as a sliding surface even in an atmosphere of acid, alkali, etc., the sliding member according to the present invention has excellent corrosion resistance and without peeling of the coating film. Abrasion resistance can be shown.

  Preferably, the carbon has a porosity of 0.5 to 15% by volume. By making the porosity within the above range, the above effect can be further enhanced.

  In particular, when the porosity is 0.5 volume% or more and less than 3.0 volume%, the surface roughness Ra of the surface of the base material on which the coating film is formed is 0.5 to The thickness is preferably 1.5 μm.

  Further, when the porosity is 3% by volume or more and less than 8% by volume, the surface roughness Ra of the surface of the base material on which the coating film is formed is 0.2 to 1.3 μm. Preferably there is.

  Moreover, when the porosity is 8% by volume or more and 15% by volume or less, the surface roughness Ra of the surface of the base material on which the coating film is formed is 0.2 to 1.0 μm. Preferably there is.

  In the above, the surface roughness Ra of the surface of the substrate is controlled within a specific range according to the porosity of the carbon. For example, when the porosity is small, the exposed area of the pores can be increased by increasing the surface roughness at the interface between the substrate and the coating film. By doing so, part of the coating film is easily filled in the pores, and adhesion between the substrate and the coating film can be easily ensured.

  Preferably, pores other than pores filled with a part of the coating film are sealed in the base material.

  By doing so, pores other than the pores already filled with a part of the coating film are also sealed. Therefore, pressure resistance as a mechanical seal using this sliding member can be secured. Furthermore, by sealing the boundary between the part where the coating film is formed and the part where the coating film is not formed, it is possible to prevent the entry of liquid or the like into the interface between the coating film and the substrate. it can. As a result, the corrosion resistance of the coating film can be improved, and for example, peeling due to hot water can be prevented.

  Preferably, the synthetic resin includes a tetrafluoroethylene resin. Since the tetrafluoroethylene resin (PTFE resin) functions as a lubricant, it can improve the slipping property on the coating film, that is, the sliding surface, and can further improve the wear resistance.

  The mechanical seal which concerns on this invention has the sliding member in any one of said as a sealing ring for fixation and / or a sealing ring for rotation. As described above, the sliding member of the present invention has good adhesion between the coating film and the substrate, and is excellent in corrosion resistance and wear resistance. Therefore, the sliding member is suitable as a sealing ring in a mechanical seal. Therefore, the mechanical seal according to the present invention can effectively prevent foreign substances such as wear powder from being mixed even in an atmosphere where corrosion resistance such as acid and alkali is required. In the mechanical seal according to the present invention, the sliding member of the present invention may be used as both a sealing ring and a sealing ring for rotation. Or you may use as a sealing ring for fixation, and you may use as a sealing ring for rotation, but it is preferable to use the sliding member of this invention for both sealing rings.

The sliding member manufacturing method according to the present invention includes a base material including carbon having pores, and a coating film formed on a surface of the base material and including PEEK resin. The base material and the coating film A sliding member in which the pores are partially filled with the coating film so as to be integrated with the coating film at the interface with
Forming the coating film on the surface of the substrate;
Heat-treating the base material on which the coating film is formed at 360 to 430 ° C.

  A coating film is formed on the surface of the substrate by a normal method, and the substrate on which the coating film is formed is heat-treated at a temperature higher than the melting point of the PEEK resin, thereby bringing the resin contained in the coating film into a molten state. Part of the coating film can be filled in the pores existing on the surface of the carbon. As a result, the coating film on the surface of the base material and a part of the coating film filled in the pores can be integrated, and a strong anchoring effect is produced at the interface between the base material and the coating film, thereby improving adhesion. Can be improved.

  In the present invention, the base material contains carbon having pores, and a coating film containing synthetic resin is formed on the surface thereof. Since this coating film is continuously filled in the pores of carbon at the interface between the base material and the coating film, the coating film is in a state of biting into the pores of carbon. As a result, an anchor effect is produced at this interface, and a sliding member with improved adhesion between the substrate and the coating film can be obtained.

  In particular, when the synthetic resin has a PEEK resin, a sliding member having excellent corrosion resistance and wear resistance can be obtained even in an atmosphere of acid, alkali, or the like. Further, by setting the porosity, surface roughness, etc. of the carbon within the above preferred ranges, it becomes possible to further improve the adhesion between the substrate and the coating film, the wear resistance, and the like.

  Moreover, according to this invention, the mechanical seal which has said sliding member as a sealing ring is obtained. The mechanical seal of the present invention has improved adhesion between the substrate and the coating film. Furthermore, since the synthetic resin includes the PEEK resin, the coating film does not peel off and is excellent in wear resistance even in an atmosphere where corrosion resistance is required, and thus exhibits good sealing performance.

  Furthermore, according to the present invention, the adhesion between the substrate and the coating film is improved by forming a coating film containing PEEK resin on the surface of the substrate by an ordinary method and heat-treating the coating film in the above temperature range. A sliding member can be obtained easily.

FIG. 1 is a schematic cross-sectional view of a mechanical seal using a sliding member according to an embodiment of the present invention and a test apparatus therefor. FIG. 2A is an electron micrograph of an interface between a sample substrate and a coating film according to an example of the present invention. FIG. 2B is an electron micrograph of the interface between the base material of the sample and the coating film according to the comparative example of the present invention.

  Hereinafter, the present invention will be described based on embodiments shown in the drawings.

Sliding member The sliding member of the present invention includes a base material and a coating film formed on the surface of the base material.

Base material The base material constituting the sliding member of the present invention contains carbon having pores. Although it does not restrict | limit especially as carbon which has a pore, The material baked at 1000-3000 degreeC can be used.

  In addition, since the carbon (base material) used in the present embodiment is produced by molding and firing carbon powder, the pores present in the carbon have a high ratio of continuous pores. Therefore, also in the sealing treatment after the formation of the coating film, which will be described later, the resin used as the sealing material is easily impregnated, and the gap existing at the interface between the substrate and the coating film can be filled through the continuous pores. .

The porosity of carbon having pores is preferably 0.5 to 15% by volume. When the porosity is too small, even if the PEEK resin contained in the coating film to be described later enters the pores, the anchor effect tends not to be obtained much. On the other hand, if it is too large, the strength of the material will be lowered, or the coating resin will be sucked into the substrate too much to form irregularities on the surface.
The porosity can be measured by a water replacement method using saturated water.

  Moreover, when said porosity is 0.5 volume% or more and less than 3.0 volume%, surface roughness Ra of the base-material surface is 0.5-1.5 micrometers, More preferably, it is 0.5-1. .3 μm is preferable. When the porosity is in the above range, since there are few exposed pores at the interface between the base material and the coating film, the anchor effect obtained by the molten coating film entering the pores is small. Therefore, by making the surface roughness Ra of the substrate surface within the above range, the contact area between the substrate and the coating film increases, the exposed area of the pores at the interface increases, and the pores filled with the coating film are reduced. Increase. As a result, the anchor effect described above can be sufficiently obtained.

  Similarly, when the porosity is 3% by volume or more and less than 8% by volume, the surface roughness Ra of the substrate surface is 0.2 to 1.3 μm, more preferably 0.3 to 1.0 μm. Preferably there is.

  Furthermore, when said porosity is 8 volume% or more and 15 volume% or less, surface roughness Ra of the base-material surface is 0.2-1.0 micrometer, More preferably, it is 0.3-0.8 micrometer. It is preferable. When the porosity is in the above range, a sufficient anchor effect can be obtained without increasing the contact area between the substrate and the coating film.

Coating Film The coating film constituting the sliding member of the present invention is not particularly limited as long as it contains at least a synthetic resin, but in this embodiment, it contains a PEEK resin. Since PEEK resin has thermal characteristics such as low thermal conductivity and high thermal expansion coefficient specific to the resin, when used on sliding surfaces where heat is generated by sliding, the sliding characteristics are affected by heat. I have the problem of being inferior.

  However, in this embodiment, a part of the coating film containing the PEEK resin enters the pores of carbon and fills the pores. Therefore, the contact area between the coating film and the base material increases, and the base material effectively dissipates frictional heat generated on the coating film (sliding surface) by sliding. Therefore, the deformation of the coating film due to heat becomes almost negligible, and the thermal characteristics of the PEEK resin do not become a problem. Furthermore, the slipperiness in the adhesion state accompanying the softening of the coating film by heat is improved, and the discharge of wear powder is also improved.

  Moreover, since the PEEK resin contained in the coating film is excellent in corrosion resistance and wear resistance, by using this, a sliding member having good corrosion resistance and wear resistance in an atmosphere of acid, alkali or the like. Can be obtained.

In the present embodiment, the coating film may further contain a tetrafluoroethylene resin (PTFE resin). PTFE resin is a solid lubricant, and by being contained in the coating film, it can improve the slipperiness on the sliding surface and improve the wear resistance. As the solid lubricant, in addition to PTFE resin, MoS ₂ (molybdenum disulfide), graphite powder, or the like may be used.

  The content of the PTFE resin is preferably 5 to 25% by weight and more preferably 10 to 15% by weight with respect to 100% by weight of the PEEK resin contained in the coating film. If the content is too small, the effect of improving the slipperiness tends not to be obtained. If the content is too large, the hardness of the coating film is lowered and scratches due to foreign matters tend to occur.

  Next, a process of forming a coating film containing PEEK resin on the surface of the substrate (carbon) will be described. First, a base material is prepared, processed into a desired shape with a lathe or the like, and degreased and washed. If necessary, the surface roughness Ra of the surface on which the coating film is to be formed is adjusted to the above range. The method for adjusting the surface roughness Ra is not particularly limited, and examples thereof include a method using sandpaper with a count corresponding to a desired surface roughness.

  Next, a coating film having PEEK resin is formed on the above surface. The forming method is not particularly limited, and examples thereof include powder coating and dispersion.

  After the coating film is formed on the surface of the substrate by the above method, heat treatment is performed to bring the resin constituting the coating film into a molten state. If it does so, in the interface of a base material and a coating film, resin of a molten state will penetrate | invade into the pore (through-hole) which exists in the surface of a base material (carbon) by capillary phenomenon, and the inside of a pore will be filled with resin. Thereafter, when cooled, since the resin filled in the pores and the coating film are integrated, a strong anchor effect is obtained between the substrate and the coating film. As a result, the adhesion between the substrate and the coating film can be improved.

  In addition, since the porosity which exists in a base material has the high ratio which is a continuous pore, resin may also impregnate the pore which does not exist in the base-material surface through the pore which exists in the base-material surface.

  Assuming that the entire pores existing as through holes on the surface of the substrate on which the coating film is formed is 100%, it is preferable that 60% or more of the pores are partially filled with the coating film. More preferably, it is 90% or more. If the ratio of pores filled (pore filling rate) is too small, the anchor effect is difficult to obtain, and the adhesion between the substrate and the coating film tends not to be improved.

  The heat treatment temperature is preferably higher than the melting point of the PEEK resin contained in the coating film, more preferably 360 ° C. or higher and 430 ° C. or lower. However, it varies depending on the holding time, the carbon porosity, the pore diameter, and the like. To do. When the heat treatment temperature is lower than the melting point of the PEEK resin, the pores are not filled, and the anchor effect cannot be obtained, so that the adhesion between the substrate and the coating film tends to be inferior. When the heat treatment temperature is too high, oxidation of the resin contained in the carbon and the coating film tends to start.

  The holding time may be longer than the time required for the molten resin to fill the pores, and varies depending on the heat treatment temperature, the porosity of the carbon, the pore diameter, etc., but is preferably 30 to 90 minutes. .

  When the porosity of carbon is 0.5 volume% or more and less than 3.0 volume%, the holding time is preferably 60 to 90 minutes.

  Moreover, when the porosity of carbon is 3 volume% or more and less than 8 volume%, it is preferable that holding time is 30 to 60 minutes.

  Moreover, when the porosity of carbon is 8 volume% or more and 15 volume% or less, it is preferable that holding time is 30 to 60 minutes.

  In the above, after forming the coating film by a normal method, a part of the coating film is filled in the pores of the carbon by performing a heat treatment, but the coating film in the molten state directly on the substrate surface May be formed to fill the pores.

  The average thickness of the coating film is preferably 0.010 to 0.100 mm. When the average thickness is too small, the wear resistance tends to be inferior. On the other hand, if the value of the average thickness is too large, heat dissipation through the carbon is hindered, and the wear powder discharge becomes worse, with the result that wear resistance tends to deteriorate.

  In the present embodiment, since the pores that are not filled with a part of the coating film exist in the sliding member (base material + coating film) after the heat treatment, in a wet atmosphere, through the pores that are not filled, There is a risk that chemicals, water vapor, or the like that promotes peeling of the coating film may enter. In order to prevent this, pores existing in the base material may be sealed with respect to the sliding member after the heat treatment. Specific examples of the sealing treatment include a treatment of impregnating only the pores of carbon with a resin to seal the pores, and the resin used is preferably a furan resin, a phenol resin, an epoxy resin, a polyester resin, or the like. By performing such a sealing treatment, in addition to the above effects, it is possible to improve the strength as a sliding member and prevent leakage of the sealed fluid.

Mechanical seal Next, the mechanical seal according to the present invention will be described in detail with reference to the drawings. FIG. 1 is a cross-sectional view of a mechanical seal and its test apparatus according to this embodiment using the sliding member of the present invention.

  In FIG. 1, the mechanical seal 1 is held via an O-ring 31 on the inner periphery of a housing 30 that surrounds the outer peripheral side of the rotary shaft 20. The seal portion of the mechanical seal 1 includes a rotation seal ring 2 and a fixing seal ring 3. In this embodiment, the sealing ring 2 for rotation and the sealing ring 3 for fixation which this mechanical seal 1 has are comprised by the sliding member of this invention. However, one sealing ring for rotation or fixing may be constituted by the sliding member of the present invention.

  The rotation sealing ring 2 is formed on a fitting surface whose inner peripheral surface is slidably fitted to the rotation shaft 20. An O-ring step is formed on one end of the fitting surface. An O-ring 24 is attached to the O-ring step so as to seal between the fitting surfaces of the rotary seal ring 2 and the rotary shaft 20.

  Further, an intermediate ring 21 having an L-shaped cross-section that holds an O-ring 24 provided on the O-ring step of the sealing ring 2 for rotation from one side is arranged in a state of being slidably fitted to the rotary shaft 20. Yes. The intermediate ring 21 is engaged with a guide pin fixed to the O-ring 24 in an axial direction and is engaged in a locked state in the circumferential direction. Further, the intermediate ring 21 is pressed by a plurality of springs 22 arranged at equal intervals in the circumferential direction of the rotating shaft 20. The plurality of springs 22 are seated in respective spring mounting holes provided in the O-ring 24, and the other ends elastically press the rotation sealing ring 2 via the intermediate ring 21. As a result, the rotation-side sliding surface 2a and the fixed-side sliding surface 3a are in contact with each other so as to be slidable. The O-ring 24 is fixed to the rotary shaft 20 by a set screw, and is held via a guide pin and a rotation stop pin so that the intermediate ring 21 and the rotation sealing ring 2 do not rotate.

  The fixing seal ring 3 is provided with an inner peripheral surface that is fitted to the rotary shaft 20, and a convex portion that is provided with a fixed-side sliding surface 3 a at the tip thereof. The fixing sealing ring 3 is provided with a fitting surface that is attached to the mounting step portion of the housing 30 in a fitted state. Further, the fixed sealing ring 3 is in contact with the support surface provided at the mounting step portion and is fixed in sliding contact with the rotating side sliding surface 2a of the rotating sealing ring 2 so as to be slidable. A back surface for supporting 3a is provided. In addition, an O-ring groove is provided in the mounting step portion of the housing 30, and an O-ring 31 is attached to the O-ring groove to seal between the two fittings.

  The mechanical seal 1 according to the present invention can be used in an atmosphere where corrosion resistance is required, such as an acid or alkali atmosphere, because the rotation sealing ring 2 and / or the fixing sealing ring 3 is constituted by the sliding member of the present invention. Good wear resistance can be exhibited.

  In particular, the mechanical seal 1 in which both the rotation sealing ring 2 and the fixing sealing ring 3 are constituted by the sliding member of the present invention has the following advantages. That is, by configuring both the rotating and stationary sealing rings with the sliding member of the present invention, it is difficult for only one of them to wear out. Furthermore, since the components of the coating film are the same, the coating film slides in a state in which the unevenness of the sliding trace generated by the sliding of the coating films (the rotating side sliding surface 2a and the fixed side sliding surface 3a) is engaged. Therefore, the sealing performance is improved as compared with the case where the smooth surfaces slide. Further, in a non-sliding state, the meshed surfaces are more closely adhered to each other due to the elastic deformation and slight repulsion of the coating film on the meshed surfaces.

  Hereinafter, the present invention will be described based on further detailed examples, but the present invention is not limited to these examples.

Example 1
Samples 1-13
Carbon having a hardness of 75 to 80 HsD and a porosity of 8 to 10% by volume (hereinafter referred to as carbon A) was prepared as a base material, and this was processed to prepare a carbon piece of φ55 × 10 mm. The surface roughness Ra of the carbon surface was 0.5 to 0.6 μm. Next, the dispersion containing the PEEK resin was diluted with water and spray-coated on the substrate surface to form a coating film (sliding surface) having an average thickness of 0.06 mm and dried. And the base material after coating film formation was heat-processed on the conditions shown in Table 1. After cooling this, it was set as the test piece of the following hot water peeling tests. For sample 3, the interface between the heat-treated substrate and the coating film was observed with an electron microscope. An electron micrograph of the interface is shown in FIG. 2A.

Hot water peeling test The above test piece was cut in half from the center with a cutting machine, and this cut surface was immersed in hot water of 0.2 MPa-120 ° C. for 1 hour. Then, after cooling to 40 ° C. or lower and drying, the presence or absence of peeling of the coating film was visually evaluated. The results are shown in Table 1.

Samples 14-16
In Samples 14-16, a coating film was formed on carbon A, heat-treated under the conditions shown in Table 1, and then the pores of carbon A were sealed with furan resin. Similarly, a test piece was prepared and a hot water peeling test was performed. The results are shown in Table 1.

Samples 17-19
In Samples 17-19, carbon having a hardness of 80-85 HsD and a porosity of 3-5% by volume (hereinafter referred to as carbon B) was used as the base material, and the heat treatment conditions were other than those shown in Table 1. Made a test piece in the same manner as Sample 3, and conducted a hot water peeling test. The results are shown in Table 1. For Sample 17, the interface between the heat-treated substrate and the coating film was observed with an electron microscope. An electron micrograph of the interface is shown in FIG. 2B.

Sample 20, 21
In Samples 20 and 21, the base material was carbon having a hardness of 55 to 60 HsD and a porosity of 12 to 15% by volume (hereinafter referred to as carbon C), and the heat treatment conditions were set to the conditions shown in Table 1. Made a test piece in the same manner as Sample 3, and conducted a hot water peeling test. The results are shown in Table 1.

Samples 22-25
In Samples 22 to 25, heat treatment conditions are shown in Table 1 using carbon having a hardness of 105 to 110 HsD and a porosity of 0.5 to 1.0% by volume as a base material (hereinafter referred to as carbon D). A test piece was prepared in the same manner as Sample 3 except that the surface roughness was changed to the value shown in Table 1 using sandpaper of No. 1200-1500 in the wet state. A test was conducted. The results are shown in Table 1.

Samples 26-28
In Samples 26 to 28, except that the carbon is the carbon shown in Table 1 and the surface roughness is set to the value shown in Table 1 using a 1200 to 1500 sandpaper in a wet state, Similarly, a test piece was prepared and a hot water peeling test was performed. The results are shown in Table 1.

Samples 1-13
From Table 1, when the base material is carbon A and the holding time during heat treatment is 30 minutes (samples 1 to 5), for samples 1 and 2 having heat treatment temperatures of 350 ° C. and 360 ° C., the coating film Local lift was observed. This is because the heat treatment temperature is low, so that the resin constituting the coating film is not sufficiently filled in the pores of carbon A, and the adhesion between the substrate and the coating film is poor.

  Further, even when the heat treatment temperature is 380 ° C., when the holding time is 15 minutes (sample 7), the resin constituting the coating film does not sufficiently reach the inside of the pores of the carbon A, and the substrate and the coating film It is thought that the result of the poor adhesion was. In Samples 1, 2, and 7 where local lifting was observed, the pore filling rate was less than 60%.

  On the other hand, when the heat treatment conditions are appropriate (samples 3 to 6, 8 to 13), the resin constituting the coating film is sufficiently filled in the pores of the carbon A, and the adhesion between the substrate and the coating film is improved. The coating film does not peel off even in the hot water test. This can also be visually confirmed from a photograph of the interface between the base material and the coating film in Sample 3 shown in FIG. 2A.

Samples 14-16
From Table 1, it can be confirmed that Sample 14 in which the coating film is formed under the same conditions as Sample 2 does not cause peeling even in the hot water test by performing the sealing treatment. The same applies to the sample 16 in which the coating film is formed under the same conditions as the sample 7. In the case where the heat treatment conditions were inappropriate (Sample 15), even when the sealing treatment was performed, local lifting of the coating film was observed in the hot water test. The pore filling rate of this sample 15 was smaller than 60%.

Samples 17-21
From Table 1, even when carbon species having different porosities (carbon B, carbon C) are used as the base material, a coating film is formed in samples (samples 18 to 21) with appropriate heat treatment conditions. It can be confirmed that the resin is sufficiently filled in the pores of the carbon and the coating film does not peel off even in the hot water test.

  On the other hand, for sample 17, as shown in FIG. 2B, it can be confirmed that the PEEK resin constituting the coating film is not sufficiently filled in the pores of carbon. As a result, in Sample 17, local lifting of the coating film was observed in the hot water test, and the pore filling rate was smaller than 60%.

Samples 22-28
When carbon D having a low porosity is used as the substrate, it can be confirmed that the rougher the surface roughness, the more likely it is not to peel in the hot water test. Moreover, about the sample whose porosity is larger than the carbon D, even if it makes surface roughness small, it can confirm that there exists a tendency for a coating film not to peel in a hot water test. In Sample 22 where local lifting was observed, the pore filling rate was less than 60%.

Samples 29 and 30
Samples 29 and 30 were the same as Sample 3 except that the base material was the material shown in Table 2, shot blasting was performed with alumina, the surface roughness was adjusted, and the heat treatment conditions were as shown in Table 2. Then, a test piece was prepared and a hot water peeling test was performed. The results are shown in Table 2.

  From Table 2, when the base material is ceramics having no pores, it can be confirmed that peeling of the coating film or local lifting occurs in the hydrothermal test even if sufficient heat treatment is performed.

Example 2
Samples 31-37
Carbon (carbon A and carbon D), carbon / SiC composite material (SiC: 30%) and SiC shown in Table 3 were prepared as base materials. Next, the dispersion containing the PEEK resin was diluted with water, spray-coated on the substrate surface, and dried. The obtained coating film of the sliding member was heat-treated under the conditions shown in Table 3. After cooling this, the carbon substrate was further impregnated with a furan resin and sealed. Then, the base material after forming the coating film is wrapped with diamond slurry and adjusted to a coating film (sliding surface) with an average thickness of 0.05 mm to produce a sliding member (sealing ring for rotation and sealing ring for fixing). did. In Samples 34 to 36, PTFE resin was contained in the coating film at a ratio shown in Table 3.

  The obtained sliding member was mounted on the mechanical seal test apparatus shown in FIG. 1 and evaluated as follows. The rotation sealing ring was concentric with a size of φ56.5 × φ77 × 26.5 mm and a rotation-side sliding surface of φ56.5 × φ75 mm. The fixing sealing ring has a concentric shape with a size of φ56 × φ81 × 27 mm and a fixed sliding surface of φ58.6 × φ66.1 mm.

Sliding test A rotating sliding test was performed by the mechanical seal test apparatus shown in FIG. The test conditions were: rotation speed: 300 rpm, seal portion atmosphere: nitrogen atmosphere, seal portion pressure: 0.2 MPa, test time: 100 hours. The evaluation was performed on the amount of wear on the rotating side sliding surface and the stationary side sliding surface after 100 hours, the temperature of 1 mm immediately below the stationary side sliding surface, and the presence or absence of abnormal noise during the sliding test. The results are shown in Table 3.

  From Table 3, when the sealing ring for fixation and the sealing ring for rotation were constituted by the sliding member of the present invention, the amount of wear was kept low and no abnormal noise was generated during sliding. The same tendency was observed when PTFE was included in the coating film. On the other hand, when the rotating seal ring was not constituted by the sliding member of the present invention (sample 37), the wear resistance deteriorated and the test was completed in 5 hours. In addition, abnormal noise was generated during the sliding test.

DESCRIPTION OF SYMBOLS 1 ... Mechanical seal 2 ... Sealing ring for rotation 2a ... Sliding surface on rotation side 3 ... Sealing ring for fixing 3a ... Sliding surface on fixed side 10 ... Coating film (PEEK resin)
12 ... Base material (carbon)
14: pores partially filled with coating film 16 ... pores not partially filled with coating film

Claims (9)

A substrate comprising carbon having pores;
A coating film formed on the surface of the base material and containing a synthetic resin;
The synthetic resin has a polyetheretherketone resin;
The average thickness of the coating film is 0.010 to 0.100 mm,
A sliding member in which a part of the coating film is filled in the pores so as to be integrated with the coating film at an interface between the base material and the coating film,
A sliding member having a pore filling rate of 60% or more, assuming that 100% of all pores existing as through holes on the surface of the substrate on which the coating film is formed.   The sliding member according to claim 1, wherein the carbon has a porosity of 0.5 to 15% by volume.   When the porosity is 0.5% by volume or more and less than 3.0% by volume, the surface roughness Ra of the surface of the substrate on which the coating film is to be formed is 0.5 to 1. The sliding member according to claim 2 which is 5 micrometers.   When the porosity is 3% by volume or more and less than 8% by volume, the surface roughness Ra of the surface of the base material on which the coating film is to be formed is 0.2 to 1.3 μm. Item 3. The sliding member according to Item 2.   When the porosity is 8% by volume or more and 15% by volume or less, the surface roughness Ra of the surface of the substrate on which the coating film is to be formed is 0.2 to 1.0 μm. Item 3. The sliding member according to Item 2.   The sliding member according to claim 1, wherein pores other than pores filled with part of the coating film are sealed in the base material.   The sliding member according to any one of claims 1 to 6, wherein the synthetic resin has a tetrafluoroethylene resin. The sliding member according to claim 1, a mechanical seal having a stationary seal ring and the rotary seal ring. A method for producing the sliding member according to claim 1,
Forming the coating film on the surface of the substrate;
And a step of heat-treating the base material on which the coating film is formed at 360 to 430 ° C.

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