Sliding resin composition and sliding resin member

Abstract

The present invention provides a sliding resin composition, etc., that exhibits excellent sliding properties when used as a sliding resin component, regardless of the amount of fluororesin or other materials blended, by blending predetermined inorganic materials. [Solution] A sliding resin composition, etc., comprising at least (A) a fluororesin as component (B) a predetermined sliding inorganic material (bornite) as component (B) and (C) a phosphate as component (C), wherein each material is included in the following proportions, thereby exhibiting excellent sliding properties over a long period of time. (A) Fluorine resin: 100 parts by weight (B) Bornite: 5-300 parts by weight (C) Phosphate: 1-100 parts by weight

Description

[Technical Field]

[0001] The present invention relates to a sliding resin composition and a sliding resin member. In particular, this invention relates to a sliding resin composition (hereinafter sometimes simply referred to as a sliding resin or resin composition) that exhibits excellent sliding properties by blending a predetermined sliding inorganic material with a fluororesin over a wide range, and to a sliding resin member (hereinafter sometimes simply referred to as a sliding member) derived therefrom. [Background technology]

[0002] Conventionally, polytetrafluoroethylene resin (hereinafter sometimes referred to as PTFE) has been used as a sliding resin for bearings and other applications because it has excellent self-lubricating properties, a low coefficient of friction, and also possesses chemical resistance and heat resistance. However, because PTFE alone has poor abrasion resistance and load-bearing capacity, it was common practice to reinforce sliding members by compounding them with solid lubricants such as graphite and molybdenum disulfide, and / or glass fibers and carbon fibers, depending on the intended use. Furthermore, the abrasion resistance and load-bearing capacity of PTFE alone were supplemented by filling and coating the pores and surface of the porous metal layer backed with a steel backing, or by filling and coating the mesh and surface of the metal mesh body with PTFE, as a whole for the sliding member.

[0003] For example, one such sliding component has been proposed: a bearing that improves seizure resistance by suppressing the exposure of the porous metal layer through improved wear resistance of the sliding layer (see, for example, Patent Document 1). More specifically, a bearing, which is one of the sliding members, is configured to sequentially include a metal substrate, a porous metal layer formed on the surface of the metal substrate and consisting of a single metal or an alloy composition, and a sliding layer covering the porous metal layer. The sliding layer consists of copper sulfide, thermoplastic resin, molybdenum disulfide, graphite, aramid fibers, and the remainder being fluororesin. It contains more than 3% by mass and less than 40% by mass of copper sulfide (CuS), 0% by mass and 4% by mass of thermoplastic resin, 0% by mass and 36% by mass of molybdenum disulfide, 0% by mass and 10% by mass of graphite, and 0% by mass and 10% by mass of aramid fibers, with the remainder being fluororesin, while it does not contain lithium phosphate.

[0004] Furthermore, sliding resins and sliding bearings using the same have been proposed, which use PTFE as the main resin component, do not use lead, and exhibit excellent friction characteristics and wear resistance even without lubrication (see, for example, Patent Document 2). More specifically, the sliding resin consists of PTFE, 1 to 30 vol% of barium sulfate with an average particle size of 0.1 to 10 μm, and 5 to 40 vol% of a solid lubricant, which is at least one particle such as molybdenum disulfide, relative to the total amount. [Prior art documents] [Patent Documents]

[0005] [Patent Document 1] Patent No. 6256569 (Claims, etc.) [Patent Document 2] Japanese Patent Publication No. 2002-20568 (Claims, etc.) [Overview of the project] [Problems that the invention aims to solve]

[0006] However, the sliding resin described in Patent Document 1 requires a small amount of thermoplastic resin relative to the total volume, to be blended with predetermined amounts of copper sulfide, thermoplastic resin, molybdenum disulfide, graphite, aramid fiber, and fluororesin. This limits the types of components that can be blended, and the sliding properties of the resulting sliding member are still insufficient. Furthermore, the proposed sliding resin completely excluded phosphate (lithium phosphate) as a compounding component, resulting in insufficient film-forming ability of PTFE on the surface of the mating material, making it difficult to obtain good sliding properties over a long period of time.

[0007] Furthermore, the sliding resin described in Patent Document 2 mainly consists of PTFE blended with 1 to 30 vol% of barium sulfate, primarily with an average particle size of 0.1 to 10 μm, and solid lubricants such as molybdenum disulfide and tungsten disulfide. However, there is a problem in that the sliding characteristics of the resulting sliding member, particularly the amount of wear measured under predetermined conditions, are still insufficient. Furthermore, the proposed sliding resin required the use of a considerable amount of barium sulfate as an inorganic material for sliding properties in PTFE, which presented a manufacturing problem as uniform dispersion was difficult.

[0008] Therefore, the present inventors diligently conducted studies to solve the above problems and, as a result, discovered that by using a predetermined sliding inorganic material (bornite) as component (B), excellent sliding properties can be exhibited over a long period of time even when blended with (A) fluororesin, etc., in a wide range of quantities, thus completing the present invention. In other words, the present invention aims to provide a sliding resin composition containing at least components (A) to (C) in a predetermined range, which, when used as a sliding member, exhibits excellent sliding properties over a long period of time, has low wear, and is highly durable, as well as a sliding member derived therefrom. [Means for solving the problem]

[0009] According to the present invention, a sliding resin composition is provided that is characterized by containing predetermined amounts of each of the following components (A) to (C), thereby solving the above-mentioned problems. (A) Fluorine resin: 100 parts by weight (B) Bornite: 5-300 parts by weight (C) Phosphate: 1-100 parts by weight In other words, by using a predetermined amount of Bornite as component (B) together with a predetermined amount of component (C) in addition to at least 100 parts by weight (synonymous with parts by mass, the same applies hereinafter) of component (A), it is possible to provide a sliding resin composition that exhibits excellent sliding properties over a long period of time when used as a sliding member, even when component (B) is blended over a wide range of conditions.

[0010] Furthermore, in constructing the sliding resin composition of the present invention, it is preferable that (A) the fluororesin is at least one of polytetrafluoroethylene resin (PTFE), ethylenetetrafluoroethylene resin (ETFE), perfluoroethylene propene copolymer (FEP), and perfluoroalkoxyalkane resin (PFA). By selecting at least one of the (A) fluororesins, it is possible to create a sliding member derived from a sliding resin composition that exhibits excellent sliding properties more effectively over a long period of time, has low wear, and is highly durable.

[0011] Furthermore, when constructing the sliding resin composition of the present invention, it is preferable that the average particle size (D50) of (B) Bornite, as an arithmetic mean of particle diameter measured in accordance with JIS Z 8819:2019, be within the range of 1 to 30 μm. Such (B) Bornite may be a natural product or an artificial product obtained through a partially human process, but by controlling its average particle size within a predetermined range, it can be uniformly dispersed in a considerable amount in (A) fluororesins, etc., and thus can be applied to various applications with different required sliding properties.

[0012] Furthermore, in constructing the sliding resin composition of the present invention, it is preferable that (C) phosphate is at least one selected from the group consisting of metaphosphate, orthophosphate, and pyrophosphate. By blending at least one of such (C) phosphates (particularly metal phosphates), during the sliding between the sliding member and the mating member, the film-forming property of the fluororesin lubricating film on the surface of the mating member (sliding surface) becomes uniform, and sliding characteristics such as low friction and wear resistance can be exhibited over a long period of time.

[0013] Moreover, when constituting the sliding resin composition of the present invention, as the (D) component, the blending amount of graphite and molybdenum disulfide, or either one of them, is preferably 50 parts by weight or less with respect to 100 parts by weight of the (A) component. By further blending a predetermined amount of such a (D) component, graphite or molybdenum disulfide can exhibit good lubricity as a solid lubricant, and in the sliding resin composition, fine adjustment of the sliding characteristics can be easily achieved.

[0014] Moreover, when constituting the sliding resin composition of the present invention, as the (E) component, the blending amount of at least one resin selected from the group consisting of polyimide resin (PI), polyacetal resin (POM), and polyphenylene sulfide resin (PPS) is preferably 170 parts by weight or less with respect to 100 parts by weight of the (A) component. By further blending a predetermined amount of such an (E) component, while maintaining wear resistance and heat resistance, the effect becomes more remarkable under the usage conditions on the high load side of the sliding member.

[0015] Moreover, another aspect of the present invention is a sliding resin member characterized by having a sliding layer derived from the sliding resin composition according to any one of the above on a base material. That is, by using a sliding member derived from a specific sliding resin composition, excellent sliding characteristics can be effectively exhibited over a long period of time, the amount of wear is small, and good handleability can be obtained when manufacturing by injection molding or the like. Note that a sliding member provided with a sliding layer derived from a sliding resin composition on a base material such as a porous metal layer may be referred to as a composite sliding member in some cases.

[0016] Furthermore, in constructing the sliding resin member of the present invention, it is preferable that the sliding resin member has the pores and / or surface of a porous metal layer formed on a steel backing plate as a base material filled and coated with a sliding resin composition. In other words, by creating a sliding resin member in which a sliding resin composition is filled and coated onto a porous metal layer (including perforated metal) as a specific base material, it is possible to effectively exhibit excellent sliding properties over a long period of time, reduce wear, and obtain excellent durability. Furthermore, by providing such a porous metal layer in the middle, not only is it easier to control the thickness, but the desired sliding resin component can be manufactured in a relatively short time. [Brief explanation of the drawing]

[0017] [Figure 1] Figure 1(a) is a cross-sectional view showing a sliding member (excluding porous metal layers, etc.) derived from the sliding resin composition of the present invention, and Figures 1(b) to (c) are cross-sectional views provided to explain the structure of another sliding member (including porous metal layers, etc.) derived from the sliding resin composition of the present invention. [Figure 2] Figure 2(a) is provided to illustrate the expanded metal contained in the porous metal layer, and Figure 2(b) is provided to illustrate the woven wire mesh contained in the porous metal layer. [Figure 3] Figure 3 shows an example of the particle size distribution of (B) bornite to be incorporated into the sliding resin composition of the present invention. [Figure 4] Figure 4 is a diagram (photograph) showing an example of the appearance of (B) Bornite, which is incorporated into the sliding resin composition of the present invention. [Figure 5] Figure 5(a) is a diagram showing the combined elemental distribution of Fe, Cu, and S in artificially produced bornite incorporated into the sliding resin composition of the invention, while Figures 5(b) to (d) show the elemental distribution of Fe, Cu, and S separately. [Figure 6] Figure 6 shows the relationship between the amount of (B) bornite in the sliding resin composition and the resulting sliding characteristics of the sliding member. [Figure 7] Figure 7 shows the relationship between the type of phosphate as component (C) in the sliding resin composition and the resulting sliding properties of the sliding member. [Figure 8] Figure 8 shows the relationship between the type of wear-resistant resin used as component (E) in the sliding resin composition and the resulting sliding characteristics of the sliding member. [Figure 9] Figures 9(a) and 9(b) show the sliding characteristics of the sliding members in Examples 1 to 10 and Comparative Examples 1 to 6, respectively. [Figure 10] Figure 10 shows an overview of the thrust friction test method used to evaluate the friction and wear of sliding members. [Modes for carrying out the invention]

[0018] [First Embodiment] The first embodiment is a sliding resin composition characterized by containing predetermined amounts of the following components (A) to (C). (A) Fluorine resin: 100 parts by weight (B) Bornite: 5-300 parts by weight (C) Phosphate: 1-100 parts by weight The sliding resin composition of the present invention will be described in detail below.

[0019] 1. (A) Component: Fluorine resin (1) Type 1 (A) Fluorine-based resins are resins that exhibit substantial lubricity and are added primarily to reduce the frictional force of the sliding layer by cooperating with components (B) and (C) by supporting them. Specifically, the types of (A) fluororesins include at least one of the following: polytetrafluoroethylene resin (PTFE), ethylene tetrafluoroethylene resin (ETFE), perfluoroethylene propene copolymer (FEP), perfluoroalkoxyalkane resin (PFA), etc.

[0020] Furthermore, it is also preferable to use other fluororesins as the fluororesin. In other words, it is also preferable to use fluororesins derived from copolymerization components (such as perfluoro(alkyl vinyl ether), hexafluoropropylene, perfluoro(alkyl vinyl ether), hexafluoropropylene, (perfluoroalkyl)ethylene, or chlorotrifluoroethylene) when polymerizing fluororesins.

[0021] In particular, PTFE, even when used almost alone, further improves durability and heat resistance when applied to sliding members, and also exhibits better lubricity and uniform dispersion as a carrier for components (B) and (C).

[0022] Furthermore, when PTFE is included as the fluororesin, it is preferable that the amount of PTFE blended be in the range of 50 to 100% by weight, more preferably in the range of 60 to 99% by weight, and even more preferably in the range of 80 to 95% by weight, with the total amount of fluororesin in the sliding resin composition being 100% by weight.

[0023] Furthermore, it is preferable that the fluororesin incorporates a three-dimensional structure and has a cross-linked structure. The reason for this is that, with cross-linked fluororesins, the glass transition temperature can typically be set to a high temperature range of 150°C or higher, further improving the durability and heat resistance when applied to sliding components. In other words, it is preferable that the fluororesin is crosslinked by irradiating an uncrosslinked fluororesin with ionizing radiation to introduce a three-dimensional structure, for example, crosslinked polytetrafluoroethylene (hereinafter sometimes referred to as crosslinked PTFE). More specifically, crosslinked PTFE can be obtained, for example, by irradiating uncrosslinked PTFE, which has been heated to a temperature higher than its crystal melting point, with ionizing radiation (e.g., gamma rays, electron beams, X-rays, neutrons, or high-energy ions, etc.) at an irradiation dose of 1 kGy to 10 MGy in an oxygen-free environment.

[0024] Furthermore, the average molecular weight (number average molecular weight, the same applies hereafter) of the fluoropolymer resin (uncrosslinked product) is 1 × 10⁻⁶. 4 ~1 × 10 7 It is preferable to use a value within the range of [value]. The reason for this is that such an average molecular weight is 1 × 10 4 This is because if the value falls below a certain level, the adhesion strength may decrease significantly, or the sliding resistance may become excessively high. On the other hand, the average molecular weight is 1 × 10 7 If the value exceeds a certain point, the shear resistance becomes high and the material becomes too hard, resulting in poor adhesion and a tendency to break down into wear particles when it peels off. Therefore, the average molecular weight of the fluororesin is 3 × 10 4 ~8×10 6 It is more preferable to use a value within the range of 5 × 10 4 ~5×10 6 It is even more preferable to use a value within the range.

[0025] Furthermore, it is preferable to restrict the molecular structure by considering the average molecular weight and type of fluororesin, as well as whether or not a cross-linking structure is introduced, in order to set the glass transition temperature within the range of 100 to 300°C. The reason for this is that if the glass transition temperature falls below 100°C, the durability and heat resistance of the sliding component may decrease significantly. On the other hand, if the glass transition temperature exceeds 300°C, the shear resistance when used as a sliding member becomes excessively large, or it becomes too hard, resulting in poor adhesion to the substrate, and it may easily turn into wear particles when peeled off. Therefore, it is more preferable to set the glass transition temperature of the fluororesin to a value in the range of 100 to 200°C, and even more preferable to set it to a value in the range of 110 to 180°C.

[0026] Furthermore, when using particulate resin as the fluororesin, it is preferable that its average particle size (D50) be within the range of 1 to 10 μm. The reason for this is that if the average particle size falls below 1 μm, sufficient lubrication cannot be obtained, and the sliding effect may decrease in a short time. On the other hand, when the average particle diameter exceeds 10 μm, the fluidity and dispersibility in the molten state during molding of the sliding member decrease, the smoothness of the surface of the sliding layer is impaired, smooth driving is hindered, and abnormal noise may occur. Therefore, when using particulate fluororesin, it is more preferable that the average particle diameter (D50) thereof is within the range of 1.5 to 8 μm, and it is still more preferable that it is within the range of 2 to 5 μm.

[0027] (2) Type 2 Also, it is preferable to use a mixture of fluororesins (high molecular weight fluororesin and low molecular weight fluororesin) having different average molecular weights. Here, when the component (A) is such a mixture, the average molecular weight of the low molecular weight fluororesin is usually 5×10 5 It is preferable to be less than this value, and it is more preferable to be less than 3×10 5 It is still more preferable to be less than 1×10 5 It is still more preferable to be less than this value. Also, the average molecular weight of the high molecular weight fluororesin is usually 5×10 5 It is preferable to be greater than or equal to this value, and it is more preferable to be 8×10 5 or more, and it is still more preferable to be 1×10 6 or more. The reason is that by using such a mixture, the sliding characteristics when used as a sliding member can be accurately controlled, or by supporting the component (B) or the component (C), in cooperation with them, mainly, the frictional force and wear amount of the sliding layer can be further reduced in some cases. For example, molding powder (hereinafter sometimes referred to as high molecular weight fluororesin) and a fluororesin (hereinafter abbreviated as low molecular weight fluororesin) that is easily pulverized and has good dispersibility by radiation irradiation or the like can be mixed and used at a predetermined ratio (for example, 1 / 99 to 50 / 50 by weight ratio) as described later.

[0028] More specifically, examples of high molecular weight fluororesins include "Teflon® 7-J," "Teflon® 7A-J," and "Teflon® 70-J" from Mitsui DuPont Fluorochemicals, "Polyflon M-12 (product name)" from Daikin Industries, and "Fluon G163 (product name)" and "Fluon G190 (product name)" from Asahi Glass Co., Ltd.

[0029] Other commercially available low molecular weight fluoropolymer resins include "TLP-10F (product name)" from Mitsui DuPont Fluorochemicals, "LeBron L-5 (product name)" from Daikin Industries, Ltd., "Fluon L150J (product name)" and "Fluon L169J (product name)" from Asahi Glass Co., Ltd., and "KTL-8N (product name)" from Kitamura Corporation.

[0030] Furthermore, when using a mixture of fluororesins with varying average molecular weights, it is preferable that the mixing ratio (by weight) of the low molecular weight fluororesin to the high molecular weight fluororesin be within the range of 1 / 99 to 50 / 50. The reason for this is that if the mixing ratio is less than 1 / 99 or greater than 50 / 50, the mixing effect may not be obtained. Therefore, it is more preferable to set the mixing ratio of the low molecular weight fluororesin / high molecular weight fluororesin to a value within the range of 5 / 95 to 45 / 55, and even more preferable to set it to a value within the range of 10 / 90 to 40 / 60.

[0031] (3) Compounding amount (A) The amount of fluororesin, which is component (A), is not particularly limited, but it is generally preferable to use a value in the range of 5 to 94% by weight relative to the total amount (100% by weight) of the sliding resin composition. The reason for this is that if the amount of fluororesin used falls below 5% by weight, the uniform dispersion of components (B) and (C) may decrease. Consequently, when a sliding member is constructed, it may be difficult to obtain sufficient lubrication, and the sliding effect may decrease in a short time. On the other hand, if the amount of fluororesin used in the formulation exceeds 94% by weight, the fluidity and dispersibility of the molten state when forming the sliding member may decrease. Consequently, when a sliding member is constructed, the smoothness of the surface of the sliding layer may be impaired, hindering smooth operation and potentially generating abnormal noise. Therefore, it is more preferable that the amount of fluororesin, which is component (A), be within the range of 10 to 80% by weight of the total amount, and even more preferable that it be within the range of 30 to 70% by weight.

[0032] 2. (B) Bornite (1) Types (B) The bornite, which is component (B), may be natural or artificial, but is a copper and iron sulfide (Cu5FeS4), or an inorganic material mainly composed of such sulfides. Furthermore, it is preferable that the average particle size (D50), which is the arithmetic mean of the particle diameters measured in accordance with JIS Z 8819:2019, is a value within the range of 1 to 30 μm. The reason for this is that by controlling the average particle size of bornite as component (B), which consists of such compounds, a good balance can be achieved between uniform dispersibility and stable, long-term lubrication effects. In other words, when the average particle size of such bornite becomes less than 1 μm, the uniform dispersion between components (A) and (C) may decrease. Consequently, when used to construct sliding members, the lubrication effect may saturate easily, and the sliding effect may decrease in a short time. On the other hand, if the average particle size of the bornite exceeds 30 μm, the uniform dispersion between component (A) and component (C) decreases, and consequently, the fluidity in the molten state when forming the sliding member may decrease significantly. Therefore, when a sliding member is constructed, the smoothness of the surface of the sliding layer may be impaired. Therefore, it is more preferable that the average particle size of component (B), bornite, be in the range of 3 to 20 μm, and even more preferable that it be in the range of 5 to 18 μm.

[0033] Figure 3 shows an example of the particle size distribution (D50) of the bornite measured using a particle size analyzer. Figure 4 shows an electron microscope image (magnification 1000) of the bornite. Furthermore, both bornite as a natural product and artificial products obtained through partial human processes share the common characteristic of having copper and iron sulfides (Cu5FeS4) as their main components. However, while naturally occurring bornite is generally bluish-green in appearance, artificially produced bornite obtained through partial human processes is generally black in appearance. Therefore, it is possible to determine this not only from elemental analysis of the material's components but also from its appearance color. Furthermore, it is possible to distinguish between naturally occurring bornite and artificially produced bornite obtained through human processes based on differences in appearance color, such as color difference, CIE chromaticity coordinate values, and even differences in FT-IR charts.

[0034] As an example, Figures 5(a) to (d) show the distribution of Fe (iron), Cu (copper), and S (sulfur) in SEM images of artificially created bornite. Specifically, Figure 5(a) shows the combined distribution of Fe, Cu, and S, while Figures 5(b) to (d) show the individual distributions of Fe, Cu, and S. Looking at the distribution of each element, it can be seen that in artificially produced bornite, Fe and Cu are uniformly and equally dispersed, while S is unevenly dispersed, with areas of high and low abundance.

[0035] (2) Compounding amount Furthermore, the amount of bornite, which is component (B), is set to a value within the range of 5 to 300 parts by weight per 100 parts by weight of component (A). The reason for this is that if the amount of bornite added is less than 5 parts by weight, it may be difficult to obtain sufficient lubrication when used in a sliding component, and the sliding effect may decrease in a short time. On the other hand, if the amount of bornite added exceeds 300 parts by weight, the fluidity and dispersibility in the molten state when forming the sliding member may be significantly reduced. Consequently, the smoothness of the surface of the sliding layer may be impaired, hindering smooth operation and potentially generating abnormal noise. Therefore, it is more preferable to set the amount of bornite to a value in the range of 10 to 200 parts by weight, and even more preferable to set it to a value in the range of 20 to 100 parts by weight, per 100 parts by weight of component (A).

[0036] Here, referring to Figure 6, we will explain the relationship between the amount of Bornite, which is component (B) in the sliding resin composition, and the resulting sliding characteristics of the sliding member. Specifically, the horizontal axis of Figure 6 shows the amount of Bornite blended in the sliding resin composition, the left axis shows the coefficient of friction (-) corresponding to line X, and the right axis shows the wear amount (μm) corresponding to line Y. Furthermore, to facilitate understanding of the effect of the amount of bornite in component (B), the basic formulation consisted of 100 parts by weight of component (A), with 9 to 50 parts by weight of aluminum metaphosphate as component (C) phosphate, 13 to 28 parts by weight of component (D) (molybdenum disulfide / graphite, etc.), and component (E) (polyimide resin, etc.) either not used or used in amounts of 40 parts by weight or less.

[0037] As can be seen from the characteristic curve in Figure 6, as the amount of bornite in the sliding resin composition increases, the coefficient of friction decreases gradually, as shown by line X, and the amount of wear decreases exponentially and significantly, as shown by line Y. More specifically, with component (A) at 100 parts by weight, in the range where the amount of bornite exceeds 0 parts by weight but is less than 50 parts by weight, the coefficient of friction decreased linearly from 0.2 to about 0.15-0.16, and the wear decreased sharply from about 25 μm to about 15 μm. Furthermore, in the range where the amount of Bornite exceeds 50 parts by weight but is less than 100 parts by weight, the coefficient of friction decreases to approximately 0.11 to 0.12, and the amount of wear decreases to approximately 12 μm. Furthermore, in the range where the amount of Bornite exceeds 100 parts by weight but is less than 300 parts by weight, the coefficient of friction is maintained at approximately 0.11 to 0.12, and the amount of wear is also maintained at approximately 12 μm. Therefore, although it depends on the types and amounts of other components in the sliding resin composition, by adjusting the amount of Bornite, which is component (B), it is possible to reliably lower the coefficient of friction when used as a sliding member to less than 0.2 and adjust the amount of wear to a desired value of less than approximately 25 μm. Furthermore, the coefficient of friction and the amount of wear when used as a sliding member can be measured according to the conditions described in Example 1, which will be described later.

[0038] 3. (C) Phosphate (1) Types Phosphates (especially metal phosphate salts) do not themselves exhibit lubricating properties like solid lubricants such as graphite or molybdenum disulfide. However, when blended with fluororesins, they promote the formation of a lubricating film of the fluororesin on the surface (sliding surface) of the mating material during sliding, thereby improving sliding properties such as low friction and wear resistance. Therefore, it is preferable that the phosphate is at least one selected from the group consisting of metaphosphate, orthophosphate, and pyrophosphate. The reason for this is that by incorporating at least one of these phosphates, the lubricating film of the fluororesin on the surface of the mating material (sliding surface) becomes uniform during sliding between the sliding member and the mating material, allowing it to exhibit sliding properties such as low friction and wear resistance over a long period of time.

[0039] Therefore, more specifically, metaphosphates include one or more of the following: aluminum metaphosphate, lithium metaphosphate, calcium metaphosphate, iron metaphosphate, tin metaphosphate, titanium metaphosphate, magnesium metaphosphate, manganese metaphosphate, etc. Furthermore, examples of orthophosphates include at least one of zinc orthophosphate, calcium orthophosphate, aluminum orthophosphate, lithium orthophosphate, and magnesium orthophosphate. Furthermore, examples of pyrophosphates include at least one of the following: aluminum pyrophosphate, calcium pyrophosphate, tin pyrophosphate, iron pyrophosphate, titanium pyrophosphate, magnesium pyrophosphate, and manganese pyrophosphate.

[0040] Furthermore, at least one of lithium metaphosphate, calcium metaphosphate, aluminum metaphosphate, calcium pyrophosphate, magnesium pyrophosphate, and manganese phosphate is the most preferred component as a phosphate because it exerts the desired effect in relatively small amounts. More specifically, examples include aluminum metaphosphate (Al(PO3)3), lithium metaphosphate (PLiO3), trilithium phosphate (Li3PO4), lithium hydrogen phosphate (Li2HPO3), lithium pyrophosphate (Li4P2O7), tricalcium phosphate (Ca3(PO4)2), calcium pyrophosphate (Ca2P2O7), and dicalcium phosphate (CaHPO4).

[0041] (2) Compounding amount Furthermore, the amount of phosphate, which is component (C), is set to a value within the range of 1 to 100 parts by weight per 100 parts by weight of component (A). In other words, by adding a relatively small amount to the fluororesin, for example, about 1 part by weight per 100 parts by weight of component (A), the effect of promoting the film-forming properties of the lubricating film mentioned above begins to appear, and this effect can be said to be maintained up to 100 parts by weight. However, if the amount exceeds 100 parts by weight, the amount of lubricating film formed on the surface of the mating material increases, which may actually reduce wear resistance. Therefore, it is more preferable to include phosphate in a value within the range of 5 to 80 parts by weight, and even more preferable to include it in a value within the range of 10 to 60 parts by weight.

[0042] Here, referring to the bar graph in Figure 7, we will explain the relationship between the types of phosphates used as component (C) in the sliding resin composition and the sliding characteristics (coefficient of friction and amount of wear) of the sliding members containing them. Specifically, the horizontal axis of Figure 7 shows the types of phosphates in the sliding resin composition, the left axis shows the coefficient of friction (-), and the right axis shows the amount of wear (μm). Furthermore, to facilitate understanding of the influence of the type of phosphate (component C), lithium metaphosphate (C1), calcium metaphosphate (C2), aluminum metaphosphate (C3), magnesium metaphosphate (C4), magnesium pyrophosphate (C5), calcium pyrophosphate (C6), and manganese phosphate (C7) were blended in the figure as phosphates, in a ratio of 19 parts by weight each per 100 parts by weight of component (A), in accordance with the sliding resin composition of Example 1, etc. Specifically, in accordance with the sliding resin composition of Example 1, the blending composition of the sliding resin composition was as follows: 100 parts by weight of component (A), 51 parts by weight of component (B), which is bornite, and 19 parts by weight of molybdenum disulfide and 1 part by weight of graphite, which are components (D).

[0043] As can be seen from the vertical bars in the bar graph of Figure 7, the type of phosphate in component (C) has a significant influence on the coefficient of friction and the amount of wear of the sliding member. For example, lithium metaphosphate (C1) and calcium metaphosphate (C2) can be used to achieve a low coefficient of friction of less than 0.1, and the amount of wear can be limited to a low value of 7 to 11 μm. Furthermore, it is understood that aluminum metaphosphate (C3) or magnesium pyrophosphate (C5) can achieve a low coefficient of friction of 0.15 and limit the amount of wear to a low value of 14-16 μm. Furthermore, with manganese phosphate (C7), the coefficient of friction is only slightly above 0.15, and it is understood that the amount of wear can be limited to a low value of about 24 μm. Therefore, by appropriately selecting the type of phosphate as component (C) in the sliding resin composition, or by using a mixture of multiple phosphates, it can be said that the coefficient of friction and the amount of wear can be precisely adjusted to the desired range, depending on the application of the sliding member.

[0044] 4.(D) Component (1) Types Furthermore, when constructing the sliding resin composition, it is preferable to include graphite and molybdenum disulfide, or one of these solid lubricants, as component (D). The reason for this is that by incorporating such component (D), graphite and molybdenum disulfide can each exhibit good lubricity as solid lubricants, making it easy to fine-tune the sliding characteristics of the sliding member derived from the sliding resin composition.

[0045] (2) Compounding amount Furthermore, it is preferable that the amount of graphite and / or molybdenum disulfide, which is component (D), be 50 parts by weight or less per 100 parts by weight of component (A). The reason for this is that by using this amount of component (D), the lubricating effect of component (B), which is bornite, can be effectively brought out, and consequently, the fine adjustment of the sliding characteristics can be easily made. In other words, if the amount of component (D) exceeds 100 parts by weight, the fluidity and dispersibility of component (B), which is bornite, that is blended into component (A) when forming the sliding member may decrease. Consequently, the smoothness of the surface of the sliding layer may be impaired. On the other hand, if the amount of component (D) is excessively low, the lubricating effect of (B) Bornite, etc., incorporated into component (A) may become saturated, and the sliding effect may decrease in a short time. Therefore, when component (D) is included, it is preferable that the amount included be in the range of 0.1 to 40 parts by weight, and more preferably in the range of 0.5 to 30 parts by weight, per 100 parts by weight of component (A).

[0046] 5.(E) Component (1) Types Furthermore, it is preferable to include at least one selected from the group consisting of polyimide resin (PI), polyacetal resin (POM), and polyphenylene sulfide resin (PPS) as component (E). The reason for this is that by further incorporating a wear-resistant resin, which is component (E), the wear resistance and heat resistance are maintained, while the effect becomes particularly noticeable under high-load operating conditions for sliding members.

[0047] Commercially available polyimide resins (PI) include aromatic polyimide resins such as Rensing's "P84 Polyimide (product name)," and thermosetting polyimide resins such as Ciba-Geigy's "Bismaleimide (product name)," Mitsui Chemicals' "Tecmite (product name)," and Nisshinbo Industries Ltd.'s "Carbodiimide (product name)."

[0048] Furthermore, polyacetal resin (POM) is a crystalline thermoplastic resin composed of (-CH2O-) polyoxymethylene structural units. Examples of commercially available polyacetal resins include "Duracon" manufactured by Daicel Corporation and "Yupital" manufactured by Mitsubishi Gas Chemical Company.

[0049] Furthermore, polyphenylene sulfide resin (PPS) is basically a crystalline resin that has a repeating structure of alternating benzene rings and sulfur atoms (usually an opaque resin, but also includes transparent and translucent resins). Examples of such commercially available products include Toray Industries' "Torelina" (product name) and Hoechst's "Ceramer" (product name).

[0050] (2) Compounding amount Furthermore, it is preferable that the amount of such component (E) is usually 170 parts by weight or less per 100 parts by weight of component (A). The reason for this is that by using this amount of component (E), the uniform mixing of component (B) with component (A) is improved, resulting in a more stable improvement in wear resistance and heat resistance, and a better balance with sliding properties. However, if the amount of component (E) is excessively low, the uniformity of mixing of component (B) with respect to component (A) will decrease, the lubricating effect of component (B) will easily saturate, and the sliding effect may decrease in a short time. Therefore, when component (E) is included, it is preferable that the amount included be in the range of 1 to 100 parts by weight, and more preferably in the range of 5 to 40 parts by weight, per 100 parts by weight of component (A).

[0051] Here, referring to Figure 8, we will explain the relationship between the blending of various wear-resistant resins into a sliding resin composition and the resulting sliding characteristics of the sliding member. Specifically, the horizontal axis of Figure 8 shows examples in which various wear-resistant resins (polyimide resin, polyacetal resin (POM), polyphenylene sulfide resin (PPS)) are blended in amounts of 10 to 20 parts by weight per 100 parts by weight of component (A). The left axis shows the coefficient of friction (-), and the right axis shows the amount of wear (μm). As can be seen from the vertical bars in Figure 8, by changing the type of wear-resistant resin, it is possible to improve the adhesion of the sliding resin composition, as well as the fluidity and dispersibility in the molten state when molding the sliding member, while controlling the coefficient of friction and amount of wear of the sliding member to a predetermined range.

[0052] For example, with polyimide resin, a blend of about 10 parts by weight per 100 parts by weight of component (A) can control the coefficient of friction to a small value of less than 0.1, and limit the amount of wear to a low value of less than 10 μm. Furthermore, with polyacetal resin (POM), a blend of approximately 10 parts by weight per 100 parts by weight of component (A) yields a friction coefficient of approximately 0.11 and an abrasion value of approximately 10 μm. Furthermore, with polyphenylene sulfide resin (PPS), a blend of approximately 20 parts by weight per 100 parts by weight of component (A) results in a friction coefficient of approximately 0.12 and an abrasion amount of approximately 12 μm. Therefore, by appropriately selecting the type and amount of wear-resistant resin as component (E) in the sliding resin composition, it can be said that the coefficient of friction and the amount of wear can be individually adjusted according to the application of the sliding member.

[0053] 6. Other ingredients It is also preferable to incorporate at least one of the following into the sliding resin composition, in addition to components (A) to (E) that exhibit sliding properties: calcined phenolic resin, copper sulfide, tungsten disulfide, glass fiber, resin powder, resin fiber, metal powder, and metal fiber, depending on the application of the sliding member. In other words, copper sulfide and the like can be blended into fluororesins to overcome the drawbacks of fluororesins alone, such as their inferior abrasion resistance and load-bearing capacity, and improve these properties. In particular, a sliding effect can be expected under low-load operating conditions for sliding members. Furthermore, when copper sulfide or the like is added, the amount added is usually preferably within the range of 100 parts by weight or less per 100 parts by weight of component (A), more preferably within the range of 0.01 to 50 parts by weight or less, and even more preferably within the range of 0.05 to 20 parts by weight or less.

[0054] Here, calcined phenolic resin is defined as a resin (carbide) obtained by carbonizing granular phenol-formaldehyde resin through high-temperature calcination at 400°C to 2200°C in an inert atmosphere. Examples of commercially available products include "Bellpearl C-800" (product name) and "Bellpearl C-2000" (product name) manufactured by Kanebo Co., Ltd.

[0055] 7. Manufacturing method A sliding resin composition can be prepared by mixing a fluororesin with the above-mentioned compounding components. Next, a petroleum-based solvent is added to the resulting mixture and stirred to obtain a sliding resin composition with improved wetting properties. Here, the mixing of the fluororesin and each compounding component is preferably carried out at a temperature below the room temperature transition point (19°C) of the fluororesin (e.g., PTFE), preferably 10 to 18°C. Furthermore, it is preferable to stir-mix the obtained mixture with the petroleum-based solvent at the same temperature as described above. In other words, this relatively low-temperature manufacturing method prevents the fibrous formation of fluororesins, making it easier to obtain a homogeneous mixture.

[0056] Here, as petroleum-based solvents, it is preferable to use naphtha, toluene, xylene, or a mixed solvent with an aliphatic solvent or a naphthenic solvent. Furthermore, the proportion of petroleum-based solvent used is preferably within the range of 15 to 30 parts by weight per 100 parts by weight of the mixture of fluororesin powder and each compounding component. The reason for this is that if the proportion of petroleum-based solvent used is less than 15 parts by weight, the spreadability of the resin composition to which wetting properties have been imparted may decrease, or unevenness may occur in the filling and coating of the sintered layer, as described later. On the other hand, if the proportion of petroleum-based solvents used exceeds 30 parts by weight, the filling and coating process may become difficult, the uniformity of the coating thickness of the resin composition may be impaired, or the adhesion strength between the resin composition and the sintered layer may decrease.

[0057] [Second Embodiment] The second embodiment is a sliding member derived from a sliding resin composition containing predetermined amounts of the following components (A) to (C). (A) Fluorine resin: 100 parts by weight (B) Bornite: 5-300 parts by weight (C) Phosphate: 1-100 parts by weight The embodiments of the sliding member of the present invention and its manufacturing method will be described in detail below. Since the sliding member of the present invention is often in the form of a film of a predetermined thickness, the invention will be described in detail assuming that a predetermined base material is included in a part of the sliding member.

[0058] 1. Base material The base material is a metal component that serves as the base for filling and coating its surface and pores with the sliding resin composition. In other words, as shown in Figure 1(a), it is preferable that the sliding member 10 of the present invention has a coating layer 13 made of a predetermined sliding resin composition formed on the surface of the steel backing 11 which serves as the base material. The reason for this configuration is that it makes it easier to process the material into various machine parts and other components. Therefore, although the material of the base material is not particularly limited, it is preferable to have a backing made of steel, carbon steel, iron, aluminum, copper, stainless steel, or an alloy thereof, from the viewpoint of wear resistance and other factors.

[0059] Furthermore, it is preferable that the base material has a porous metal layer on the surface of the steel backing plate that has pores for filling with a sliding resin molded product. In other words, as shown in Figure 1(b), as an example, it is preferable to provide a porous metal layer 12, which is a sintered body of a predetermined metal powder, on the surface of the steel backing plate 11, and to form a coating layer 13 by filling and coating the pores and surface of the porous metal layer 12 with a sliding resin composition to form a composite sliding member 10'. The reason for this configuration is that it improves the adhesion between the steel backing plate and the coating layer, making it possible to more effectively prevent peeling of the coating layer even when it is slid over a long period of time.

[0060] Furthermore, as shown in Figure 1(c), as another example, it is preferable to provide a wire mesh on the surface of the steel backing plate 11 and to form a coating layer 13' by filling and coating the pores and surface of the wire mesh with a sliding resin composition to form a composite sliding member 10''. The reason for this configuration is that, by using this method, the mesh acts as a core material for the sliding resin composition, thereby increasing its strength, such as wear resistance.

[0061] First, a composite sliding member (I) and a method for manufacturing the same will be described, using a base material consisting of a backing plate made of a thin steel sheet and a porous metal layer backing thereon. General structural rolled steel sheets are used as the backing material for the base. Furthermore, while it is preferable to use continuous strips of steel plate provided as hoop material wound in a coil shape, the material is not necessarily limited to continuous strips; strips cut to an appropriate length can also be used. These strips may also be coated with copper or tin plating, if necessary, to improve their corrosion resistance.

[0062] Furthermore, the metal powder used as the base material to form the porous metal layer is generally copper alloy powder that passes through approximately 100 mesh, such as bronze, lead bronze, or phosphor bronze, which have excellent friction properties. However, depending on the purpose, powders other than copper alloys, such as aluminum alloys or iron, can also be used. The particle form of this metal powder can be lumpy, spherical, or irregular. Preferably, this porous metal layer is firmly bonded to the alloy powders themselves and to strips such as steel plates, and has a certain thickness and the required porosity.

[0063] Furthermore, it is preferable that the thickness of the porous metal layer used as the base material is typically within the range of 0.15 to 0.4 mm. The reason for this is that when the thickness of the porous metal layer is less than 0.15 mm, it becomes difficult to stably manufacture the composite sliding member, or it may be difficult to obtain the durability and good sliding properties of the composite sliding member. On the other hand, if the thickness of the porous metal layer exceeds 0.4 mm, the overall weight of the composite sliding member also increases, making it difficult to handle, and in some cases, it may be difficult to obtain good sliding properties. Therefore, it is preferable that the thickness of the porous metal layer be within the range of 0.18 to 0.35 mm, and more preferably within the range of 0.2 to 0.33 mm. Furthermore, it is generally preferable that the porosity of the porous metal layer be 10% by volume or more relative to the total volume, more preferably in the range of 13 to 40% by volume, and even more preferably in the range of 15 to 35% by volume.

[0064] 2. Manufacturing method 1 (1) Preparation of base material 1 (a) Preferably, a resin composition that has been made wettable is sprayed onto a porous metal layer formed on a backing plate made of a thin steel sheet, and rolled with a roller to fill the sintered layer with the resin composition and to form a coating layer of the resin composition of uniform thickness on the surface of the sintered layer. In this coating layer formation process, the thickness of the formed coating layer is usually preferably 2 to 2.2 times the thickness of the coating layer required for the final product. Furthermore, with such a coating thickness, the filling of the resin composition into the pores of the porous metal layer proceeds mostly during this process.

[0065] (b) Next, it is preferable to remove the petroleum-based solvent by holding the backing metal processed in step (a) in a drying oven heated to a temperature of 200 to 250°C for several minutes. Next, it is preferable to apply pressure roller treatment to the dried resin composition using rollers, usually under a pressure of 30 to 60 MPa, until it reaches a predetermined thickness.

[0066] (c) Next, the backing metal processed in step (b) is introduced into a heating furnace and fired at a temperature of 360 to 380°C for 1 to 30 minutes, which is preferable. Then, it is preferable to remove the product from the heating furnace and adjust any dimensional variations by roller processing again.

[0067] (d) Next, it is preferable to cool the backing plate that has been dimensionally adjusted in step (c) (by air cooling or natural cooling). Furthermore, if necessary, it is preferable to perform a straightening roller treatment to correct any waviness in the backing plate, thereby creating the desired sliding member.

[0068] In this manner, in the sliding member obtained through steps (a) to (d), it is preferable that the thickness of the porous metal layer is usually within the range of 0.10 to 0.40 mm, and the thickness of the coating layer formed from the sliding resin composition is within the range of 0.02 to 0.15 mm. Furthermore, the sliding members obtained in this manner are preferably cut to appropriate dimensions and used as flat plates, or bent into a cylindrical shape and used as coiled bushings.

[0069] 3. Manufacturing method 2 Next, another sliding member (II) of the present invention and a method for manufacturing the same, which uses a base material made of a metal mesh, will be described. First, the following types (i) to (iii) are typical examples of metal mesh materials that form the base material. (i) An expanded metal is formed by feeding a thin metal sheet between a fixed lower die having a straight blade and a movable upper die having a wave-shaped, trapezoidal, triangular, or other blade, either perpendicular to the blade of the fixed lower die or at an angle to the blade of the fixed lower die, and then moving the movable upper die back and forth in the vertical direction to cut into the thin metal sheet and simultaneously expand the cuts to form a regular mesh pattern. (ii) A woven wire mesh formed by weaving thin metal wires as warp and weft threads. (iii) A braided wire mesh formed by weaving thin metal wires.

[0070] Here, as shown in Figure 2(a), the expanded metal is typically made by expanding a thin metal sheet with a thickness of 0.3 to 2 mm, resulting in a strand length of 0.1 to 1.5 mm and a thickness of 0.1 to 1.0 mm. On the other hand, the woven wire mesh 16 and braided wire mesh included in the composite sliding member 10'' shown in Figure 2(b) are typically formed by weaving or braiding thin metal wires with a diameter of 0.1 to 0.5 mm as vertical wires 16a and horizontal wires 16b into a mesh of 10 to 100 mesh.

[0071] Suitable metal materials for forming expanded metal, woven wire mesh, or braided wire mesh include stainless steel, copper, phosphor bronze, bronze, and iron.

[0072] Therefore, the sliding member (II) is preferably manufactured through the following steps (a') to (c'), and it is preferable to use the same resin composition as described in the manufacturing method of the sliding member (I) as the resin composition used to coat it.

[0073] (a') Preferably, a resin composition is sprayed onto a metal mesh made of expanded metal, woven or braided wire mesh, and rolled with a roller to fill the mesh of the metal mesh with the resin composition and form a coating layer of the resin composition of uniform thickness on the surface of the metal mesh. In the process of forming such a coating layer, the thickness of the coating layer is usually preferably 2 to 2.5 times the coating thickness required for the final product from the sliding resin composition.

[0074] (b') Next, it is preferable to remove the petroleum-based solvent by holding the metal mesh processed in step (a') in a drying oven heated to a temperature of 200 to 250°C for several minutes. Then, it is preferable to apply pressure roller treatment to the dried resin composition with a roller to a predetermined thickness, usually under a pressure of 30 to 60 MPa.

[0075] (c') Next, the metal mesh processed in step (b') is introduced into a heating furnace and is preferably heated at a temperature of 360-380°C for several minutes to more than ten minutes to bake the resin composition. Furthermore, it is preferable to remove the material from the heating furnace and adjust the dimensional variations again by roller processing to obtain the desired sliding member.

[0076] Thus, in the sliding member (II) obtained through each of the steps (a') to (c'), the thickness of the coating layer made of the resin composition formed on the surface of the metal mesh is usually 0.05 to 1.0 mm. The sliding member obtained in this manner is preferably cut to an appropriate size and used as a sliding plate in a flat state, or bent into a round shape and used as a cylindrical coiled bushing. [Examples]

[0077] The present invention will be described in more detail below with reference to examples, but the present invention is not limited to the following examples unless it exceeds the essence of the invention.

[0078] <Composition ingredients> In each example and comparative example, the following raw materials were used as ingredients.

[0079] (A) component (A1) High molecular weight PTFE (Daikin Industries, Ltd., Polyflon F201 (product name)) was prepared as component (A1). (A2) As component, another high molecular weight PTFE resin (Teflon 6CJ (trade name) manufactured by Mitsui DuPont Fluorochemicals) was prepared. (A3) As component, a low molecular weight PTFE resin (Daikin Industries, Ltd., Rubron L-5) was prepared.

[0080] (B) Component As component (B1), we prepared artificially produced bornite, which is black in color, consists of aggregated particles as shown in Figure 4, and has a particle size distribution (D50: 15 μm) as shown in Figure 3. (B2) As component, artificially produced bornite was prepared, which is black, aggregated particles, and has a predetermined particle size distribution (D50: 22 μm). As component (B3), artificially produced bornite was prepared, which is black, aggregated particles, and has a predetermined particle size distribution (D50: 8 μm).

[0081] (C) Component Lithium metaphosphate was prepared as component (C1). Calcium metaphosphate was prepared as component (C2). Aluminum metaphosphate was prepared as component (C3). Magnesium metaphosphate was prepared as component (C4). Magnesium pyrophosphate was prepared as component (C5). Calcium pyrophosphate was prepared as component (C6). Manganese phosphate was prepared as component (C7).

[0082] (D) Component As component (D1), molybdenum disulfide (manufactured by Daito Lubrication Co., Ltd., LM-12) was prepared. As component (D2), flake graphite (manufactured by Nippon Graphite Industries Co., Ltd., J-ACP) was prepared.

[0083] (E) Component As component (E1), a thermosetting polyimide resin (Tecmite, manufactured by Mitsui Chemicals, Inc.) was prepared. As component (E2), polyphenylene sulfide resin (DURAST FHD30, manufactured by Daicel Corporation) was prepared. As component (E3), polyacetal resin (Duracon M90-FK, manufactured by Daicel Corporation) was prepared.

[0084] As component (F1), a mixed solvent of an aliphatic solvent and a naphthenic solvent (weight ratio: 50 / 50) was prepared. A petroleum-based solvent was prepared as component (F2).

[0085] [Example 1] 1. Preparation of sliding resin composition The following ingredients were placed in the Henschel mixer in the specified proportions. (A1) Ingredients: 90 parts by weight of high molecular weight PTFE (A3) Ingredients: 10 parts by weight of low molecular weight PTFE (B1) Ingredients: 51 parts by weight of bornite (C1) Ingredient: 19 parts by weight of lithium metaphosphate (D1) Ingredients: 19 parts by weight of molybdenum disulfide (D2) Ingredients: 1 part by weight of graphite Furthermore, as component (F1), a mixed solvent of an aliphatic solvent and a naphthenic solvent (weight ratio: 50 / 50) was added in a ratio of 20 parts by weight per 100 parts by weight of the total amount of components (A) to (D) (and if component (E) is also included, the total amount of components (A) to (E)). Next, using a Henschel mixer, the mixture was stirred and mixed at a rotation speed of 60 RPM until uniform, to obtain a mixture for the sliding resin composition. Next, 20 parts by weight of a petroleum-based solvent were added to 100 parts by weight of the resulting mixture, and the mixture was further stirred and mixed until homogeneous at a temperature below the glass transition point of PTFE (15°C) to obtain a sliding resin composition.

[0086] 2. Creation of sliding members The obtained sliding resin composition was sprayed onto a porous metal layer (made of sintered bronze, 0.25 mm thick) formed on a steel backing plate (0.70 mm thick) made of a thin metal sheet. Next, the sliding resin composition was rolled using a pressure roller to a thickness of 0.25 mm, and a multilayer plate was obtained in which the pores and surface of the porous metal layer were filled and coated with the sliding resin composition. Next, the obtained multilayer board was held in a hot air drying oven heated to 200°C for 5 minutes to remove the solvent, resulting in a multilayer board with a sliding resin composition layer. Next, the resulting multilayer plate was rolled with a pressure roller at a pressure of 40 MPa to obtain a sliding resin composition layer with a thickness of 0.10 mm.

[0087] Next, the multilayer board obtained in this manner was heated and fired in a heating furnace at 370°C for 10 minutes. Next, the composite sliding member 10' was subjected to further pressure treatment at 40 MPa using a pressure roller to adjust dimensions and correct any waviness, as shown in Figure 1(b). Next, the obtained composite sliding member was cut to obtain a test piece consisting of a square composite sliding member with sides of 30 mm. Here, the porous metal layer is illustrated in Figures 2(a) and 2(b). Figure 2(a) is a plan view showing expanded metal as the base material, and Figure 2(b) is a cross-sectional view showing an example of a sliding member using woven wire mesh as the base material.

[0088] 3. Evaluation of sliding members (1) Measurement of friction coefficient and wear amount Using a thrust friction tester, the coefficient of friction and wear amount were measured for test specimens made of composite sliding members as sliding resin components under the following thrust conditions. Furthermore, the coefficient of friction was measured during the stable period from one hour after the start of the test until the end of the test. In addition, the amount of wear was measured from the dimensional change of the sliding surface after 8 hours of testing. Specifically, as shown in Figure 10, the end face of the cylinder 33, which is used as a test sample, was pressed against the flat plate test piece 38 in direction B and rotated in direction A, and the friction generated at that time was measured. Here, Table 1 and Figure 9(a) show the sliding characteristics (coefficient of friction and amount of wear) of the sliding member in Example 1.

[0089] Sliding speed: 10m / min Load: 10 MPa Exam duration: 8 hours Environmental temperature: Room temperature (25℃) Lubricant: Not used (dry condition) Countering material: Stainless steel (SUS304)

[0090] [Examples 2-12] In Examples 2 to 12, the type and amount of PTFE in component (A), the type and amount of bornite in component (B), the type and amount of phosphate in component (C), the type and amount of graphite / MoS2 in component (D), and the type and amount of abrasion-resistant resin in component (E) were changed as shown in Table 1. Next, a sliding resin composition was prepared, similar to Example 1, and a composite sliding member was created as a sliding resin component derived therefrom. The coefficient of friction and wear amount were then measured. Table 1 and Figure 9(a) also show the sliding characteristics (coefficient of friction and amount of wear) of the sliding members in Examples 2 to 12.

[0091] In other words, in Example 2, the following components were blended as follows: 100 parts by weight of component (A), 90 parts by weight of component (A1), 10 parts by weight of component (A3), 51 parts by weight of component (B1), 19 parts by weight of component (C2), 19 parts by weight of component (D1), and 1 part by weight of component (D2). A sliding resin composition was prepared and evaluated in the same manner as in Example 1.

[0092] In Example 3, the following components were added to 100 parts by weight of component (A): 90 parts by weight of component (A1), 10 parts by weight of component (A3), 51 parts by weight of component (B1), 19 parts by weight of component (C3), 19 parts by weight of component (D1), and 1 part by weight of component (D2). A sliding resin composition was prepared and evaluated in the same manner as in Example 1.

[0093] In Example 4, as the compounding components, 100 parts by weight of component (A), 100 parts by weight of component (A1), 45 parts by weight of component (B1), 9 parts by weight of component (C3), and 28 parts by weight of component (D1) were blended together to create a sliding resin composition in the same manner as in Example 1, and it was evaluated.

[0094] In Example 5, as the blending components, 90 parts by weight of component (A1), 10 parts by weight of component (A3), 51 parts by weight of component (B1), 19 parts by weight of component (C4), 19 parts by weight of component (D1), and 1 part by weight of component (D2) were blended with 100 parts by weight of component (A), and a sliding resin composition was prepared and evaluated in the same manner as in Example 1.

[0095] In Example 6, as the blending components, 92 parts by weight of component (A2), 8 parts by weight of component (A3), 33 parts by weight of component (B2), and 33 parts by weight of component (C5) were blended with 100 parts by weight of component (A), and a sliding resin composition was prepared and evaluated in the same manner as in Example 1.

[0096] In Example 7, as the blending components, 80 parts by weight of component (A2), 20 parts by weight of component (A3), 64 parts by weight of component (B3), 20 parts by weight of component (C5), and 16 parts by weight of component (D2) were blended with 100 parts by weight of component (A), and a sliding resin composition was prepared and evaluated in the same manner as in Example 1.

[0097] In Example 8, as the blending components, 90 parts by weight of component (A1), 10 parts by weight of component (A3), 51 parts by weight of component (B1), 19 parts by weight of component (C6), 19 parts by weight of component (D1), and 1 part by weight of component (D2) were blended with 100 parts by weight of component (A), and a sliding resin composition was prepared and evaluated in the same manner as in Example 1.

[0098] In Example 9, as the blending components, 100 parts by weight of component (A), 100 parts by weight of component (A1), 200 parts by weight of component (B1), 40 parts by weight of component (B2), 20 parts by weight of component (C3), 20 parts by weight of component (C5), 12 parts by weight of component (D1), 8 parts by weight of component (D2), and 40 parts by weight of component (E1) were blended together to create a sliding resin composition in the same manner as in Example 1, and it was evaluated.

[0099] In Example 10, as the blending components, 100 parts by weight of component (A), 100 parts by weight of component (A1), 113 parts by weight of component (B1), 13 parts by weight of component (B2), 13 parts by weight of component (C3), 8 parts by weight of component (D1), 5 parts by weight of component (D2), and 25 parts by weight of component (E2) were blended together to create a sliding resin composition in the same manner as in Example 1, and it was evaluated.

[0100] In Example 11, as the blending components, 100 parts by weight of component (A), 100 parts by weight of component (A1), 33 parts by weight of component (B1), 33 parts by weight of component (B3), 17 parts by weight of component (C5), 17 parts by weight of component (C7), 17 parts by weight of component (D1), 17 parts by weight of component (D2), and 100 parts by weight of component (E2) were blended to create a sliding resin composition in the same manner as in Example 1, and it was evaluated.

[0101] In Example 12, as the blending components, 100 parts by weight of component (A), 100 parts by weight of component (A2), 100 parts by weight of component (B1), 100 parts by weight of component (B3), 25 parts by weight of component (C5), 25 parts by weight of component (C7), 25 parts by weight of component (D1), 25 parts by weight of component (D2), and 150 parts by weight of component (E3) were blended together to create a sliding resin composition in the same manner as in Example 1, and it was evaluated.

[0102] [Table 1]

[0103] [Comparative Example 1] In Comparative Example 1, while no bornite (component B) was added as a compounding component, 56 parts by weight of copper sulfide was added per 100 parts by weight of component A, along with 21 parts by weight of aluminum metaphosphate (component C1) and 31 parts by weight of component D1. Otherwise, a sliding resin composition was prepared in the same manner as in Example 1, and a composite sliding member was created as a sliding resin component derived therefrom. The coefficient of friction and wear amount were then measured. Table 1 and Figure 9(b) also show the sliding characteristics (coefficient of friction and amount of wear) of the sliding member in Comparative Example 1. In the case of Comparative Example 1, since no bornite (component B) was added at all, the coefficient of friction was relatively high at 0.2, and the amount of wear was also relatively high at 25 μm.

[0104] [Comparative Examples 2-6] In Comparative Examples 2 to 6, instead of adding any bornite (component B) as a compounding component, 14 to 56 parts by weight of copper sulfide, other compounding components other than (A) to (E), were added to 100 parts by weight of (A) to (E). Except for changing the types and amounts of (A) to (E), a sliding resin composition was prepared in the same manner as in Example 1, and a composite sliding member was prepared as a sliding resin member derived therefrom. The coefficient of friction and wear amount were then measured. Table 1 and Figure 9(b) also show the sliding characteristics (coefficient of friction and amount of wear) of the sliding members in Comparative Examples 2 to 6.

[0105] Specifically, in Comparative Example 2, as the blending components, 100 parts by weight of component (A), 100 parts by weight of component (A1), no bornite of component (B) was added at all, while 56 parts by weight of copper sulfide was added, 21 parts by weight of component (C3), and 31 parts by weight of component (D1) were added, respectively, and a sliding resin composition was prepared and evaluated in the same manner as in Example 1.

[0106] In Comparative Example 3, as the blending components, 100 parts by weight of component (A), 100 parts by weight of component (A1), 40 parts by weight of copper sulfide were added, 20 parts by weight of component (C4), 20 parts by weight of component (D2), and 20 parts by weight of component (E1) were added, respectively, and a sliding resin composition was prepared and evaluated in the same manner as in Example 1.

[0107] In Comparative Example 4, as the blending components, 100 parts by weight of component (A), 100 parts by weight of component (A2), no bornite of component (B) was added at all, while 36 parts by weight of copper sulfide was added, 27 parts by weight of component (C4), and 18 parts by weight of component (E2) were added, respectively, and a sliding resin composition was prepared and evaluated in the same manner as in Example 1.

[0108] In Comparative Example 5, as the blending components, 100 parts by weight of component (A), 100 parts by weight of component (A2), and 33 parts by weight of copper sulfide were added, along with 17 parts by weight of component (C5), 13 parts by weight of component (D2), and 3 parts by weight of component (E2). A sliding resin composition was prepared and evaluated in the same manner as in Example 1.

[0109] In Comparative Example 6, as the blending components, 100 parts by weight of component (A), 100 parts by weight of component (A2), no bornite of component (B) was added at all, while 14 parts by weight of copper sulfide was added, and 7 parts by weight of component (C4), 7 parts by weight of component (C5), 11 parts by weight of component (D2), and 3 parts by weight of component (E3) were blended, respectively, and a sliding resin composition was prepared and evaluated in the same manner as in Example 1.

[0110] [Table 2] [Industrial applicability]

[0111] As described in detail above, the sliding resin composition of the present invention uses, at least, components (A) and (C), along with a sliding inorganic material, which is bornite as component (B), and is blended with a fluororesin (100 parts by weight) of component (A), which is a lubricating resin, in a wide blending range (for example, 5 to 300 parts by weight). In other words, not only can the coefficient of friction be reduced over a wide range, but excellent low wear can also be achieved. For example, under the measurement conditions shown in Example 1, the amount of wear can be controlled to a value of less than 25 μm, more preferably 20 μm or less. Therefore, even if the amount of bornite varies, or if the dispersibility of bornite is slightly reduced, excellent sliding properties can be obtained.

[0112] Furthermore, according to the sliding resin composition of the present invention, even when various solid lubricants, such as molybdenum disulfide or graphite, are used in combination with at least component (A) and component (C), and even when Bornite is blended within a wide range of formulations, it is possible to control the friction coefficient to be smaller in each case, and to obtain an even better low wear value.

[0113] Furthermore, according to the sliding resin composition of the present invention, even when various wear-resistant resins, such as polyacetal, polyphenylene sulfide, and polyimide resin, are used in combination with components (A) and (C), and even when Bornite is blended within a wide range of formulations, it is possible to control the friction coefficient to be small in each case, and to obtain even better low wear values.

[0114] Therefore, the sliding resin composition of the present invention can be used in a wide range of fields as various sliding members, and is expected to be particularly suitable for use in technical fields such as bearings for automobile parts, electrical and electronic products, and office equipment, where increased wear due to sliding is a problem. [Explanation of symbols]

[0115] 10, 10', 10'': Sliding member (composite sliding member) 11: Steel backing 12: Porous metal layer (expanded metal) 13: Covering layer 16: Woven wire mesh 16a: Vertical line 16b: Horizontal line

Claims

1. A sliding resin composition comprising at least the following components (A) to (C), characterized in that it contains them in the following amounts. (A) Fluorine resin: 100 parts by weight (B) Bornite: 5 to 300 parts by weight (C) Phosphate: 1 to 100 parts by weight

2. The sliding resin composition according to claim 1, characterized in that the (A) fluorine-based resin is at least one of polytetrafluoroethylene resin, ethylenetetrafluoroethylene resin, perfluoroethylenepropene copolymer, and perfluoroalkoxyalkane resin.

3. The sliding resin composition according to claim 1 or 2, characterized in that the average particle size of the (B) Bornite, as an arithmetic mean of the particle diameters measured in accordance with JIS Z 8819:2019, is within the range of 1 to 30 μm.

4. The sliding resin composition according to claim 1 or 2, characterized in that the (C) phosphate is at least one selected from the group consisting of metaphosphate, orthophosphate, and pyrophosphate.

5. The sliding resin composition according to claim 1 or 2, characterized in that the amount of graphite and molybdenum disulfide, or either one, as component (D) is 50 parts by weight or less per 100 parts by weight of component (A).

6. The sliding resin composition according to claim 1 or 2, characterized in that the amount of at least one resin selected from the group consisting of polyimide resin, polyacetal resin, and polyphenylene sulfide resin as component (E) is 170 parts by weight or less per 100 parts by weight of component (A).

7. A sliding resin member characterized by having a sliding layer derived from the sliding resin composition described in claim 1 or 2 on a substrate.

8. The sliding resin member according to claim 7, characterized in that the pores and / or surface of a porous metal layer formed on the steel backing as the base material are filled and coated with the sliding resin composition.

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