Sliding member and method for producing the same

Abstract

To provide a sliding member featuring a small coefficient of friction and a small specific wear rate.SOLUTION: The present invention provides: a sliding member comprising molded polyamide, the sliding member having a sliding surface, wherein the ten-point average roughness RZJIS of the sliding surface is 10 to 200 μm; a method for producing the sliding member, the method comprising performing surface treatment on the sliding surface of the sliding member after molding, to adjust the ten-point average roughness RZJIS of the sliding surface to 10 to 200 μm; and a method for producing the sliding member, the method comprising using a mold with an uneven transfer surface during molding, to adjust the ten-point average roughness RZJIS of the sliding surface of the sliding member to 10 to 200 μm.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a slide member and a method for manufacturing the same. [Background technology]

[0002] Polyamide has an excellent balance between mechanical properties such as strength and toughness and sliding properties, and is therefore widely used as sliding members such as gears, bearings, cams, washers, etc. For example, Patent Documents 1 and 2 disclose sliding members and gears made of Polyamide 10T.

[0003] In recent years, sliding components have become smaller and have higher rotational speeds, which requires the sliding components to have higher heat resistance and higher friction characteristics. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] JP 2013-064420 A [Patent Document 2] JP 2022-116418 A Summary of the Invention [Problem to be solved by the invention]

[0005] Resin sliding members, such as the sliding members and resin gears of Patent Documents 1 and 2, are generally manufactured by injection molding to reduce costs. However, sliding members manufactured by injection molding have a large friction coefficient and specific wear rate because the sliding surface is flat and has a large contact area. As a result, they may generate heat when used under harsh sliding conditions such as high speed and high pressure, resulting in large energy loss and insufficient durability.

[0006] In view of the above-mentioned conventional techniques, an object of the present invention is to provide a sliding member having a small friction coefficient and a small specific wear rate. [Means for solving the problem]

[0007] As a result of intensive research into solving the above problems, the present inventors have found that by providing fine irregularities on the sliding surface of a sliding member, specifically, the ten-point average roughness of the sliding surface of the sliding member can be reduced. RzJIS By setting the thickness of the surface roughness to 10 to 200 μm, the contact area of ​​the sliding surface becomes appropriately small, and a medium such as air, water, oil, etc. is easily retained on the sliding surface, so that the friction coefficient becomes low both in an unlubricated state and in a lubricated state. As a result, a sliding member with a low specific wear rate can be obtained, and the inventors have found that the above-mentioned problems can be solved, and have arrived at the present invention.

[0008] That is, the gist of the present invention is as follows. (1) A sliding member formed by molding polyamide, the sliding member having a sliding surface, and a ten-point average roughness R of the sliding surface ZJIS The sliding member has a surface roughness of 10 to 200 μm. (2) The sliding member according to (1), wherein the polyamide has a melting point of 270 to 350° C. as a base resin. (3) The sliding member according to (1) or (2), wherein the polyamide comprises an aromatic dicarboxylic acid component and a diamine component, and the aromatic dicarboxylic acid component is a semi-aromatic polyamide having terephthalic acid as a main component as a base resin. (4) The sliding member according to (3), wherein the diamine component of the semi-aromatic polyamide is mainly composed of 1,10-decanediamine. (5) The sliding member according to any one of (1) to (4), wherein the polyamide further contains a fibrous reinforcing material. (6) After molding, the sliding surface of the sliding member is surface treated to obtain the ten-point average roughness R ZJIS The method for producing a sliding member according to any one of (1) to (5), wherein the thickness is 10 to 200 μm. (7) By using a mold having an uneven transfer surface during molding, the ten-point average roughness R of the sliding surface of the sliding member is ZJIS The method for producing a sliding member according to any one of (1) to (6), wherein the thickness is 10 to 200 μm. Effect of the Invention

[0009] According to the present invention, it is possible to provide a sliding member having a small friction coefficient and a small specific wear rate. [Brief description of the drawings]

[0010] [Figure 1] Roughness curve of plate test piece (blast-treated surface) before friction and wear test obtained in Example 3 [Diagram 2] Roughness curve of plate test piece (embossed surface) before friction and wear test obtained in Example 14 [Diagram 3] Roughness curve of plate test piece (flat surface) before friction and wear test obtained in Comparative Example 3 DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0011] (Sliding member) The sliding member of the present invention is a sliding member formed by molding a polyamide. The resin has a polyamide as a base resin. In the present invention, the base resin refers to the resin that has the largest mass ratio among the resins used.

[0012] In the present invention, the polyamide may be classified according to the polymerization method, such as a polycondensate of dicarboxylic acid and diamine, a ring-opening polymer of cyclic lactam, or a polycondensate of aminocarboxylic acid, and may be classified according to the monomer component, such as an aliphatic polyamide, a semi-aromatic polyamide, an alicyclic polyamide, or a copolymer thereof. The polyamide may be used alone, or may be a copolymer or a mixture of two or more kinds of polyamides.

[0013] Specifically, examples of aliphatic polyamides include polyamide 6, polyamide 10, polyamide 11, polyamide 12, polyamide 46, polyamide 56, polyamide 66, polyamide 510, polyamide 610, polyamide 612, and polyamide 1010. Examples of semi-aromatic polyamides include polyamide 4T (T: terephthalic acid), polyamide 4I (I: isophthalic acid), polyamide 6I, polyamide 7T, polyamide 8T, polyamide 9T, polyamide 10T, polyamide 11T, polyamide 12T, polyamide MXD6 (MXD: metaxylylenediamine), and polyamide PXD10 (PXD: paraxylylenediamine). Examples of alicyclic polyamides include polyamide 6C (C: 1,4-cyclohexanedicarboxylic acid), polyamide 7C, polyamide 8C, polyamide 9C, polyamide 10C, polyamide 11C, and polyamide 12C. Furthermore, examples of copolymers include PA66 / 6, PA6T / 6, PA6T / 12, PA6T / 46, PA6T / 66, PA6T / 610, PA6T / 612, PA6T / 6I, PA6T / 6I / 66, PA6T / M5T (M5: methylpentadiamine), PA6T / TM6T (TM6: 2,2,4- or 2,4,4-trimethylhexamethylenediamine), and PA6T / MMCT (MMC: 4,4'-methylenebis(2-methylcyclohexylamine)) when the carbon number of the diamine is 6. As the polyamide, these polyamides may be used alone, or copolymers or mixtures of two or more polyamides may be used.

[0014] The polyamide base resin is preferably a polyamide having a melting point of 270 to 350°C, and more preferably a polyamide having a melting point of 300 to 350°C. Since the polyamide has a melting point of 270°C or higher, it has heat resistance and chemical resistance at high temperatures and can withstand a reflow process with a maximum temperature of about 260°C. On the other hand, when the polyamide has a melting point of more than 350°C, the decomposition temperature of the amide bond is about 350°C, so carbonization and decomposition may progress during melt processing. As the polyamide having a melting point of 270 to 350°C, polyamide 46, polyamide 6T, polyamide 9T, polyamide 10T, and copolymers thereof are preferred because of their high industrial versatility. In the present invention, the melting point is the top value of the endothermic peak measured using a differential scanning calorimeter DSC-7 (manufactured by PerkinElmer) in a nitrogen atmosphere, by heating to 360°C at a heating rate of 20°C / min, holding at 360°C for 5 minutes, lowering to 0°C at a heating rate of 20°C / min, holding at 0°C for a further 5 minutes, and then heating again at a heating rate of 20°C / min.

[0015] The polyamide is preferably composed of an aromatic dicarboxylic acid component and a diamine component, and the aromatic dicarboxylic acid component is preferably a semi-aromatic polyamide having terephthalic acid as a main component as a base resin. By using terephthalic acid as a main component, a semi-aromatic polyamide having a high melting point, low water absorption, and high crystallinity can be obtained. The content of terephthalic acid in the dicarboxylic acid component is preferably 60 mol% or more, more preferably 80 mol% or more, and even more preferably 90 mol% or more. The diamine component constituting the polyamide is preferably composed mainly of a diamine having 6 or more carbon atoms. By using a diamine having 6 or more carbon atoms as a main component, a semi-aromatic polyamide having high heat resistance, low water absorption, excellent chemical resistance, and high crystallinity can be obtained. Among them, a diamine having 9 or more carbon atoms is preferable, a diamine having 10 or more carbon atoms is more preferable, and a diamine having 10 carbon atoms is even more preferable. Examples of diamines having 6 or more carbon atoms include 1,10-decanediamine (carbon number 10), 1,9-nonanediamine (carbon number 9), 2-methyl-1,8-octanediamine (carbon number 9), 1,6-hexanediamine (carbon number 6), and 2-methyl-1,5-pentanediamine (carbon number 6).Preferred semi-aromatic polyamides include polyamide 6T, polyamide 9T, polyamide 10T, and copolymers thereof, and more preferred among these are polyamide 10T and copolymers thereof.

[0016] The polyamide may be copolymerized with other components such as dicarboxylic acid components other than terephthalic acid and diamines having 6 or more carbon atoms, diamine components, lactam components, and ω-aminocarboxylic acid components. However, when the other components are copolymerized, the heat resistance, abrasion resistance, and durability are reduced, so it is preferable not to copolymerize the other components. Even when the other components are contained, the total copolymerization amount of them is preferably 5 mol % or less based on the total mole number of the raw material monomers.

[0017] Examples of the other dicarboxylic acid components include aromatic dicarboxylic acids such as phthalic acid, isophthalic acid, and naphthalenedicarboxylic acid, aliphatic dicarboxylic acids such as oxalic acid, malonic acid, succinic acid, glutaric acid, adipic acid, pimelic acid, suberic acid, azelaic acid, sebacic acid, undecanedioic acid, and dodecanedioic acid, and alicyclic dicarboxylic acids such as cyclohexanedicarboxylic acid.

[0018] Examples of the other diamine components include aliphatic diamines such as 1,2-ethanediamine, 1,3-propanediamine, 1,4-butanediamine, 1,5-pentanediamine, 1,6-hexanediamine, 2-methyl-1,5-pentanediamine, 1,7-heptanediamine, 1,8-octanediamine, 1,9-nonanediamine, 2-methyl-1,8-octanediamine, 1,11-undecanediamine, and 1,12-dodecanediamine; alicyclic diamines such as cyclohexanediamine; and aromatic diamines such as xylylenediamine and benzenediamine.

[0019] Examples of the lactam component include caprolactam, undecanelactam, and laurolactam.

[0020] Examples of the ω-aminocarboxylic acid component include aminocaproic acid and 11-aminoundecanoic acid.

[0021] The relative viscosity of the polyamide used in the present invention is preferably 1.8 or more, more preferably 1.8 to 3.5, and even more preferably 2.2 to 3.1, because the mechanical properties are improved. If the polyamide has a relative viscosity of more than 3.5, melt processing may be difficult. In the present invention, the relative viscosity is a value measured in 96% sulfuric acid at 25°C and a concentration of 1 g / dL.

[0022] The method for producing the polyamide used in the present invention is not particularly limited, but the conventionally known heat polymerization method or solution polymerization method can be used. Among them, the heat polymerization method is preferably used because it is industrially advantageous.

[0023] The polyamide used in the present invention is preferably further made to contain a fibrous reinforcing material. Examples of the fibrous reinforcing material include glass fiber, carbon fiber, boron fiber, asbestos fiber, polyvinyl alcohol fiber, polyester fiber, acrylic fiber, wholly aromatic polyamide fiber, polybenzoxazole fiber, polytetrafluoroethylene fiber, kenaf fiber, bamboo fiber, hemp fiber, bagasse fiber, high-strength polyethylene fiber, alumina fiber, silicon carbide fiber, potassium titanate fiber, brass fiber, stainless steel fiber, steel fiber, ceramic fiber, basalt fiber, and wollastonite. Among them, glass fiber and carbon fiber are preferred because they have a large effect of improving mechanical properties and are easily available.

[0024] When using a fibrous reinforcing material, it is preferable that the fibrous reinforcing material is surface-treated with a silane coupling agent in order to improve dispersibility. The silane coupling agent may be used in combination with a sizing agent. Examples of the silane coupling agent include vinyl silane-based, acrylic silane-based, epoxy silane-based, and amino silane-based. Among them, amino silane-based coupling agents are preferred because they have a high adhesion effect with polyamide and excellent heat resistance.

[0025] The fiber length of the fibrous reinforcing material is not particularly limited, but is preferably 0.1 to 7 mm, and more preferably 0.5 to 6 mm. By having the fiber length of the fibrous reinforcing material be 0.1 to 7 mm, polyamide can be reinforced without adversely affecting moldability. In addition, the fiber diameter of the fibrous reinforcing material is not particularly limited, but is preferably 3 to 20 μm, and more preferably 5 to 14 μm. By having the fiber diameter of the fibrous reinforcing material be 3 to 20 μm, polyamide can be reinforced without being broken during melt kneading. Examples of the cross-sectional shape of the fibrous reinforcing material include circular, rectangular, elliptical, and other irregular cross sections.

[0026] When a fibrous reinforcing material is used, its content is preferably 5 to 130 parts by mass, more preferably 5 to 60 parts by mass, based on 100 parts by mass of polyamide. By including the fibrous reinforcing material, abrasion resistance and durability in a high-temperature environment are improved. If the content exceeds 130 parts by mass, not only is the effect of improving abrasion resistance and durability saturated and no further improvement can be expected, but also workability during melt kneading is reduced, making it difficult to obtain pellets of the resin composition.

[0027] The polyamide used in the present invention may further contain other additives such as a sliding property improver, an antioxidant, a light stabilizer, a heat stabilizer, a filler other than the fibrous reinforcing material, a colorant, and an antistatic agent, as necessary. Examples of the sliding property improver include graphite, molybdenum disulfide, polytetrafluoroethylene, and ultra-high molecular weight polyethylene. Examples of the antioxidant include hindered phenol-based antioxidants, sulfur-based antioxidants, and phosphorus-based antioxidants. Examples of the light stabilizer include hindered amine-based light stabilizers. Examples of the heat stabilizer include copper-based heat stabilizers and polyhydric alcohol-based heat stabilizers. Examples of the filler other than the fibrous reinforcing material include swelling clay minerals, silica, alumina, and glass beads. Examples of the colorant include pigments such as titanium oxide and carbon black, and dyes such as nigrosine. Examples of the antistatic agent include anionic antistatic agents, cationic antistatic agents, and nonionic antistatic agents. When the above additives are used, the total content thereof is preferably 0.01 to 10.0 parts by mass, and more preferably 0.05 to 5.0 parts by mass, relative to 100 parts by mass of polyamide.

[0028] When polyamide is mixed with fibrous reinforcing materials and other additives to be used as a polyamide resin composition, the mixing method is preferably a melt-kneading method. Examples of the melt-kneading method include a method using a batch kneader such as a Brabender, a Banbury mixer, a Henschel mixer, a helical rotor, a roll, a single-screw extruder, a twin-screw extruder, etc. The melt-kneading temperature is not particularly limited as long as the polyamide used is melted and does not decompose, but if it is too high, the polyamide decomposes, so it is preferably (melting point of polyamide -20°C) or more and (melting point of polyamide +40°C) or less.

[0029] The molten polyamide resin composition can be processed into various shapes by a method such as extruding the composition into a strand shape and forming it into a pellet shape, hot cutting or underwater cutting into a pellet shape, extruding the composition into a sheet shape and cutting it, or extruding the composition into a block shape and pulverizing it into a powder shape.

[0030] (Method of manufacturing slide member) The sliding member of the present invention is obtained by molding the polyamide or the polyamide resin composition described above. Examples of the molding method include injection molding, extrusion molding, blow molding, sintering molding, compression molding, and cutting molding, and the injection molding method is preferred because it has a large effect of improving mechanical properties and moldability and is excellent in productivity.

[0031] The injection molding machine is not particularly limited, and examples thereof include screw in-line injection molding machines and plunger injection molding machines. The polyamide or polyamide resin composition heated and melted in the cylinder of the injection molding machine is measured for each shot, injected in a molten state into a mold, cooled and solidified in a predetermined shape, and then removed from the mold as a molded body. The resin temperature during injection molding is more preferably at least (melting point of polyamide -20°C) and less than (melting point of polyamide +40°C).

[0032] When melt processing polyamide or polyamide resin composition, it is preferable to use polyamide pellets or polyamide resin composition pellets that have been sufficiently dried. If polyamide pellets or polyamide resin composition pellets containing a large amount of water are used, the resin may foam in the cylinder of the injection molding machine, making it difficult to obtain an optimal sliding member. The water content of the polyamide pellets or polyamide resin composition pellets used for injection molding is preferably 0.1% by mass, more preferably less than 0.06% by mass.

[0033] The sliding member of the present invention has a sliding surface, and the ten-point average roughness R of the sliding surface ZJIS It is necessary that the thickness is 10 to 200 μm. ZJIS By setting the range, the contact area of ​​the sliding surface becomes appropriately small, and the sliding surface is easily retained by a medium such as air, water, oil, etc., and the friction coefficient becomes low both in an unlubricated state and in a lubricated state, and as a result, a sliding member having a small specific wear rate can be obtained. Note that there is no particular restriction on the ten-point average roughness of the surface of the sliding member at a portion other than the sliding surface.

[0034] Ten-point average roughness R of the sliding surface of the sliding member ZJIS The method of imparting the thickness of 10 to 200 μm is not particularly limited, but examples thereof include a method of surface-treating the sliding surface of the sliding member after molding, and a method of using a mold having irregularities on the transfer surface during molding. The former method and the latter method may be used alone or in combination, but even if a sliding member having irregularities imparted to its sliding surface is surface-treated, the irregularities imparted before the surface treatment will be crushed by the surface treatment.

[0035] Methods for surface treating the sliding surface of the sliding member after molding include, for example, polishing treatment with an abrasive or polishing paper, blasting treatment in which fine particles are sprayed at high speed, chemical etching treatment using a chemical or acid, etc., dimple processing treatment in which fine holes are formed, and laser ablation.

[0036] The method of molding using a mold with an uneven transfer surface is a method of molding using a mold with a finely uneven transfer surface (for example, a mold with a ten-point average roughness RZJIS In this method, a mold having a surface roughness of 10 to 200 μm is used to transfer the uneven shape of the mold surface during molding. A mold with a finely uneven transfer surface can be applied to any molding method. The method for surface-treating the transfer surface of the mold to a finely uneven shape is not particularly limited, but examples include polishing with an abrasive or polishing paper, blasting with fine particles at high speed, chemical etching using chemicals or acid, dimple processing for drilling fine holes, and laser ablation. Methods for processing a mold include cutting, grinding, electric discharge machining, and rough polishing. Generally, a rough surface is further polished to obtain a smooth mold surface, but a method in which the sliding surface is left as a rough surface without polishing may also be used.

[0037] The friction coefficient of the sliding member of the present invention is preferably 0.08 or less, and more preferably 0.05 or less. 3 / (km·kN) or less is preferable.

[0038] The sliding member of the present invention is less prone to energy loss and has excellent durability and wear resistance, so that both the sliding member itself and the mating material of the sliding member are less prone to wear. Therefore, it can be suitably used as bearings, bearing retainers, various gears, cams, washers, end face materials of mechanical seals, valve seats, V-rings, rod packings, piston rings, rotating shafts and rotating sleeves of compressors, pistons, vanes, rotors, rollers, oil seals, etc. of power equipment used in electric and electronic equipment. In addition, the sliding member of the present invention can be suitably used in both a lubricated state using water, various oils, greases, etc. as a lubricant and an unlubricated state without using a lubricant. EXAMPLES

[0039] The present invention will be described in more detail below with reference to examples, but the present invention is not limited to these examples.

[0040] 1. Evaluation method The polyamide and polyamide resin composition were evaluated and measured by the following methods. (1) Melting point Using a differential scanning calorimeter DSC-7 (PerkinElmer), the sample was heated to 360°C at a rate of 20°C / min under a nitrogen atmosphere, then held at 360°C for 5 minutes, cooled to 0°C at a rate of 20°C / min, held at 0°C for a further 5 minutes, and then heated again at a rate of 20°C / min. The top value of the endothermic peak was taken as the melting point.

[0041] (2) Surface roughness The obtained plate test pieces were measured for the ten-point average roughness R of the sliding surface in accordance with JIS B 0601 (2013) using a 3D shape measuring instrument VR-3000 manufactured by Keyence Corporation. ZJIS was measured. Specifically, on the roughness curve of the reference length, the sum of the average of the peak heights from the highest peak to the fifth highest peak and the average of the valley depths from the deepest valley to the fifth deepest valley was calculated.

[0042] (3) Friction coefficient and specific wear rate (under grease lubrication) A thin layer of heat-resistant grease (M-HGSSC-H500, manufactured by Misumi) was applied to the lubricated surface of the obtained plate molded piece, and a test was performed according to JIS K 7218 A method using a Suzuki-type friction and wear tester (EFM-3-HS, manufactured by A&D Co., Ltd.) under the following conditions: abrasive wheel made of S45C steel as the mating material, load of 0.75 MPa, speed of 0.5 m / s, and friction distance of 3 km (100 min). The specific wear amount of the molded piece was calculated from the difference between the mass of the plate molded piece before and after the test. The friction coefficient was calculated as the value of the friction force detector / the value of the load, and the average friction coefficient was calculated from the average of the friction distances of 1.5 to 3 km.

[0043] (4) Friction coefficient and specific wear rate (immersed in oil) Using the obtained plate molded piece, a test was performed in accordance with JIS K 7218 A method using a Suzuki-type friction and wear tester (EFM-3-HS type manufactured by A&D Co., Ltd.) under the conditions of abrasive wheels made of S45C steel as the mating material, a load of 0.75 MPa, a speed of 0.5 m / s, and a friction distance of 3 km (100 minutes) while immersed in oil. The oil used was TOYOTA AUTO FLUID TYPE T-IV manufactured by ExonMobile. The specific wear amount of the molded piece was calculated from the difference between the mass of the plate molded piece before the test and the mass after the test. In addition, the friction coefficient was calculated as the value of the friction force detector / the value of the load, and the average friction coefficient was calculated from the average of the friction distances of 1.5 to 3 km.

[0044] (5) Friction coefficient, specific wear rate (unlubricated) The specific wear rate and coefficient of friction were determined by carrying out the same procedure as in (3), except that no heat-resistant grease was applied.

[0045] 2.Raw materials The raw materials used in the examples and comparative examples are shown below. (1) Polyamide or polyamide resin composition (A-1) Unitika XecoT XN501 (non-reinforced polyamide 10T), melting point 315℃ (A-2) XecoT XG510A30D (glass-reinforced polyamide 10T resin composition) manufactured by Unitika Ltd., melting point 315℃ (A-3) XecoT XB510A30D (carbon-reinforced polyamide 10T resin composition) manufactured by Unitika Ltd., melting point 315℃ (A-4) XecoT XL515A45 (glass-reinforced polyamide 10T resin composition, solid lubricant blended), manufactured by Unitika Co., Ltd., melting point 315°C (A-5) Unitika nylon A1030GFL (glass-reinforced polyamide 6 resin composition) manufactured by Unitika Ltd., melting point 220°C (A-6) Unitika Malanil A175S (glass-reinforced polyamide 66 resin composition), melting point 265°C

[0046] Example 1 The polyamide (A-1) was injection molded using an injection molding machine (Japan Steel Works, Ltd., J35AD-30H type) under conditions of a cylinder temperature (melting point + 15°C), a mold temperature of 130°C, and a molding cycle of 30 seconds, to prepare plate test pieces measuring 40 x 40 mm and 3 mm thick. The surface of the plate test piece was blasted to obtain a plate test piece having fine irregularities on the surface. The blasting machine used was a blast cabinet BA-1S manufactured by Atsuji Tekko Co., Ltd., and the blasting agent (K800S manufactured by SABLUX Co., Ltd.) was sprayed for 10 seconds.

[0047] Examples 2 to 3, 6 to 10 Except for changing the polyamide resin or polyamide resin composition used as shown in Table 1, the same procedure as in Example 1 was carried out to obtain plate test pieces having fine irregularities on the surface.

[0048] Example 4 The same procedure as in Example 1 was carried out, except that the surface of the plate test piece obtained in Example 1 was polished with #600 sandpaper, to obtain a plate test piece having fine irregularities on the surface.

[0049] Example 5 The same procedure as in Example 1 was carried out to obtain a plate test piece having fine irregularities on its surface, except that the surface of the plate test piece obtained in Example 1 was treated with dimples having a diameter of 0.5 mm and a depth of 150 μm at intervals of 1 mm.

[0050] Example 11 For polyamide (A-1), an injection molding machine (Japan Steel Works, J35AD-30H type) was used, and the cylinder temperature was set at (melting point + 15°C), the mold temperature was set at 130°C, and the molding cycle was set at 30 seconds. The area corresponding to the sliding surface was embossed (R ZJIS The specimens were injection molded using a mold with a diameter of 40 mm and a thickness of 3 mm, and had fine irregularities on the surface. No surface treatment was performed after injection molding.

[0051] Examples 12 to 15 The same procedure as in Example 1 was carried out except that the polyamide resin or polyamide resin composition used was changed as shown in Table 1, to obtain plate test pieces having fine irregularities on the surface.

[0052] Comparative Examples 1 to 10 Except for changing the polyamide resin or polyamide resin composition used as shown in Table 1, the same procedure as in Example 1 was carried out to obtain plate test pieces.

[0053] Table 1 shows the surface roughness, lubrication state, friction coefficient, and specific wear rate of the plate test specimens obtained in the examples and comparative examples.

[0054] [Table 1]

[0055] The plate test pieces of Examples 1, 2, 3 to 5, 6, 7, 8, 9, 10, 12, and 14 to 15 have a surface roughness R ZJIS Since the thickness of the sliding member was 10 to 200 μm, a lubricated state was always maintained, and the friction coefficient and specific wear rate were smaller than those of Comparative Examples 1, 2, 3, 4, 5, 6, 7, 8, 9, and 10 in which the sliding surface of the sliding member was not surface-treated after molding and a mold having an uneven transfer surface was not used during molding. In addition, the plate test pieces of Examples 11 and 13 had a surface roughness R ZJIS In the case of Comparative Examples 9 and 10, the friction coefficient and the specific wear rate were small, even in an unlubricated state, because the thickness of the surface roughness was 10 to 200 μm.

[0056] The plate test pieces of Comparative Examples 1 to 8 have a surface roughness R ZJIS Since the diameter of the surface roughness was less than 10 μm, even when lubricated with grease or immersed in oil, the lubricated state could not be maintained for a long time, and the friction coefficient and specific wear rate were large.

Claims

1. A sliding member formed by molding polyamide, The sliding member has a sliding surface, The ten-point average roughness R of the sliding surface ＺＪＩＳ The sliding member has a thickness of 10 to 200 μm.

2. 2. The sliding member according to claim 1, wherein the polyamide has a melting point of 270 to 350° C. as a base resin.

3. the polyamide comprises an aromatic dicarboxylic acid component and a diamine component, 3. The sliding member according to claim 1, wherein the aromatic dicarboxylic acid component is a semi-aromatic polyamide having terephthalic acid as a main component as a base resin.

4. 4. The sliding member according to claim 3, wherein the diamine component of the semi-aromatic polyamide is mainly composed of 1,10-decanediamine.

5. 3. The sliding member according to claim 1, wherein the polyamide further contains a fibrous reinforcing material.

6. After molding, the sliding surface of the sliding member is surface-treated to obtain the ten-point average roughness R ＺＪＩＳ The method for producing a sliding member according to claim 1 or 2, wherein the thickness is 10 to 200 μm.

7. By using a mold having an uneven transfer surface during molding, the ten-point average roughness R ＺＪＩＳ The method for producing a sliding member according to claim 1 or 2, wherein the thickness is 10 to 200 μm.

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