WO2019202772A1

WO2019202772A1 - Sliding member and method for producing same

Info

Publication number: WO2019202772A1
Application number: PCT/JP2018/044999
Authority: WO
Inventors: 秀高林; 忍大久保; 真玄上田; 敦市川
Original assignee: 株式会社豊田自動織機
Priority date: 2018-04-19
Filing date: 2018-12-06
Publication date: 2019-10-24
Also published as: JP7010128B2; JP2019189679A

Abstract

Provided is a sliding member in which a sliding layer can exhibit excellent sliding characteristics in terms of wear resistance. The sliding member of the present invention is equipped with a base material and a sliding layer. The sliding layer is formed on the base material and slides with an opposing material. The sliding layer contains a binder resin, a solid lubricant, and an inorganic filler. The solid lubricant is an ultrahigh-molecular-weight polyethylene having a melting point of from 126.4°C to 132.0°C. The inorganic filler is particulate titanium oxide. The titanium oxide is from 1 vol% to 8 vol% relative to the total solid components in the sliding layer.

Description

Sliding member and manufacturing method thereof

The present invention relates to a sliding member and a manufacturing method thereof.

Conventionally, sliding members disclosed in Patent Documents 1 and 2 are known. These sliding members include a base material made of a steel material or an aluminum material and a sliding layer formed on the base material. In some cases, an underlayer is provided between the base material and the sliding layer. The sliding layer contains a binder resin and a solid lubricant. The binder resin is made of an epoxy resin or the like. The solid lubricant of Patent Document 1 is composed of particulate molybdenum disulfide (MoS ₂ ), particulate polytetrafluoroethylene (PTFE), and particulate polyethylene. In recent years, ultrahigh molecular weight polyethylene has been studied from the characteristics of self-lubricating property and wear resistance, and the solid lubricant of Patent Document 2 contains particulate crosslinked ultrahigh molecular weight polyethylene.

These sliding members can be used for propeller shafts, pistons, and the like in which the sliding layer slides with the mating member. In particular, in the sliding layer of Patent Document 1, since polyethylene having a good affinity with a lubricant is included as a solid lubricant, a low friction coefficient and high wear resistance are being achieved. Moreover, in the sliding layer of patent document 2, it is trying to implement | achieve high heat resistance other than seizure resistance and abrasion resistance, using crosslinked ultrahigh molecular weight polyethylene as a solid lubricant.

JP 2013-189869 A Japanese Unexamined Patent Publication No. 2016-69508

However, the sliding member is desired to further improve the sliding characteristics in order to ensure reliability. In this regard, according to the test results of the inventors, even if the crosslinked ultrahigh molecular weight polyethylene is adopted as a part of the solid lubricant, the crosslinked ultrahigh molecular weight polyethylene is simply irradiated with radiation. If so, the sliding layer cannot always exhibit high heat resistance. In some cases, the crosslinked ultra-high molecular weight polyethylene becomes brittle, and on the contrary, the lubricating properties of the sliding layer are deteriorated.

In addition, the sliding layer containing the crosslinked ultra-high molecular weight polyethylene may have seizure resistance, abrasion resistance, and heat resistance, but depending on the application in which the sliding layer of the sliding member is used, further wear resistance Improvement of the property is desired.

The present invention has been made in view of the above-described conventional situation, and as a problem to be solved, the sliding layer can provide a sliding member that can exhibit excellent sliding characteristics in terms of wear resistance. Yes.

The sliding member of the present invention includes a base material, and a sliding layer formed on the base material and containing a binder resin, a solid lubricant, and an inorganic filler, and the sliding layer slides with a counterpart material. A sliding member that moves,
The solid lubricant is an ultra high molecular weight polyethylene having a particulate shape and a melting point of 126.4 ° C. or higher and 132.0 ° C. or lower.
The inorganic filler is particulate titanium oxide,
The titanium oxide is 1% by volume or more and 8% by volume or less with respect to all solid components in the sliding layer.

According to the test results of the inventors, when the sliding layer contains titanium oxide and the melting point of the ultra high molecular weight polyethylene is within this range, the wear resistance of the sliding layer is improved. This is presumably because the ultra-high molecular weight polyethylene is appropriately cross-linked, so that the cross-linked ultra-high molecular weight polyethylene is unlikely to elute from the surface of the sliding layer at high temperatures. Further, since the sliding layer has particulate titanium oxide, and the titanium oxide is 1% by volume or more and 8% by volume or less with respect to the total solid components in the sliding layer, the titanium oxide is slid with the partner agent. It is presumed that this is because the load acting between the moving layer is supported and the ultra high molecular weight polyethylene is difficult to fall off.

According to the test results of the inventors, the ultra high molecular weight polyethylene preferably has a gel fraction of 26% or more. In this case, since the ultra high molecular weight polyethylene having a gel fraction within this range is appropriately cross-linked, the friction coefficient of the sliding layer is low, the wear amount is small, and the ultra high molecular weight polyethylene from the surface of the sliding layer at high temperatures. Is presumably because it is difficult to elute.

The sliding layer preferably contains a silane coupling agent. In this case, it is estimated that the ultra-high molecular weight polyethylene is more difficult to elute from the surface of the sliding layer at high temperatures and to drop off because the silane coupling agent bonds the ultra-high molecular weight polyethylene and titanium oxide to the binder resin. Is done.

In the sliding layer, it is preferable that ultra high molecular weight polyethylene is 10% by volume or more and 35% by volume or less with respect to all solid components in the sliding layer. In this case, the sliding layer can further improve the wear resistance in a dry environment.

The sliding layer contains a silane coupling agent, and the silane coupling agent is preferably 0.2% by volume or more and 8% by volume or less with respect to all solid components in the sliding layer. Also in this case, the sliding layer can further improve the wear resistance in a dry environment.

In the sliding layer, the solid lubricant is 12.0% by volume or more and 29.0% by volume or less with respect to the binder resin, and the silane coupling agent is 1% by volume or more with respect to all solid components in the sliding layer, It is preferably 5% by volume or less. In this case, the sliding layer can further improve the wear resistance in a dry environment and an oil-in-water environment.

The manufacturing method of the sliding member of the present invention is a manufacturing method of a sliding member for manufacturing a sliding member that slides with a counterpart material,
A crosslinking step of irradiating the particulate ultrahigh molecular weight polyethylene in a sealed state to crosslink the ultrahigh molecular weight polyethylene;
A composition preparation step for preparing a sliding layer composition comprising a solid lubricant containing the ultrahigh molecular weight polyethylene crosslinked in the crosslinking step, a binder resin, and an inorganic filler that is particulate titanium oxide. When,
And a sliding layer forming step of providing a sliding member by providing the sliding layer composition on a base material to form a sliding layer that slides with the counterpart material.

The sliding member of the present invention can be manufactured by the manufacturing method of the present invention.

The composition adjusting step preferably further contains a silane coupling agent. In this case, ultra high molecular weight polyethylene and titanium oxide can be firmly bonded to the binder resin.

According to the sliding member of the present invention, the sliding layer can exhibit excellent sliding characteristics in terms of wear resistance. Moreover, the manufacturing method of this invention can manufacture the sliding member in which a sliding layer can exhibit the sliding characteristic outstanding in the point of abrasion resistance.

FIG. 1 is a schematic perspective view showing a state of a ring-on-disk friction and wear test. FIG. 2 is a schematic perspective view showing a state of a ball-on-disk friction and wear test.

<Crosslinking process>
As means for irradiating the particulate ultrahigh molecular weight polyethylene in a hermetically sealed state, (1) a vacuum method in which the inside of the container containing the particulate ultrahigh molecular weight polyethylene is evacuated and the proportion of air is reduced, (2) A gas purge method or the like that fills the container with an inert gas or nitrogen and discharges air can be employed. As long as it is sealed, an atmosphere containing some oxygen may be used without using a vacuum method or a gas purge method.

As the radiation, in addition to α rays, β rays and γ rays, X rays, electron rays and ion rays can be adopted. The amount of radiation is expressed as a dose proportional to the energy absorbed by the unit mass. Gray (Gy) is a unit that represents the amount of energy (referred to as absorbed dose) absorbed by a substance when the radiation hits the substance.

<Composition preparation process>
(Binder resin)
Binder resin has solid lubricant retention that makes it difficult to remove the solid lubricant, durability against shearing force that repeatedly acts under the layered film (hardness as a base), abrasion resistance, heat resistance, etc. Demonstrate. As the binder resin, polyimide resin, epoxy resin, phenol resin, or the like can be used. As the polyimide resin, polyamide imide (PAI), polyimide, or the like can be used. In consideration of cost and characteristics, it is optimal to use PAI as a binder resin.

(Solid lubricant)
The solid lubricant is held by the binder resin and exhibits a low shear force and a low friction coefficient on the outermost surface. As the solid lubricant, ultrahigh molecular weight polyethylene, fluororesin, or the like can be employed. Ultra high molecular weight polyethylene and fluororesin improve slipperiness by forming a film on the sliding surface of the sliding layer and transferring it to the mating material. Molybdenum dioxide and graphite improve slipperiness by a crystal structure having a low shear force, and realize low friction under a high load. According to the results of experiments by the inventors, the fluororesin has sliding properties such as wear resistance and seizure resistance, but has oil repellency, and the contact angle of the lubricating oil is relatively low. large. On the other hand, although ultrahigh molecular weight polyethylene is inferior to fluororesin in terms of sliding properties, it has oleophilic properties, and the contact angle of lubricating oil is relatively small. As the solid lubricant, soft metals such as molybdenum dioxide, graphite, melamine cyanurate (MCA), calcium fluoride, copper, and tin can be employed. In particular, moderately crosslinked ultrahigh molecular weight polyethylene is difficult to elute from the surface of the sliding layer at high temperatures, and can improve excellent seizure resistance and wear resistance.

The average molecular weight of the ultrahigh molecular weight polyethylene before crosslinking is preferably 1 million to 7 million. The crosslinked ultrahigh molecular weight polyethylene is preferably contained in a range of 12 to 61% by volume with respect to 100% by volume of the binder resin. When the addition amount of the crosslinked ultrahigh molecular weight polyethylene is small, the effect of addition is reduced. When the addition amount is large, supplementation by the binder resin is reduced, and the particles fall off to reduce the sliding characteristics of the sliding layer.

The specific gravity of the ultrahigh molecular weight polyethylene before crosslinking is preferably 0.92 to 0.96. The ultra high molecular weight polyethylene before crosslinking preferably has a particle diameter of 30 μm or less, more preferably 15 μm or less, from the viewpoint of surface smoothness and wear resistance.

(filler)
The sliding layer may have a filler in addition to the binder resin and the solid lubricant. As the filler, those that improve the hardness of the sliding layer, such as hard particles such as titanium oxide, tricalcium phosphate, alumina, silica, silicon carbide, and silicon nitride, can be employed. In view of cost and characteristics, it is optimal to employ titanium oxide as an inorganic filler.

As the silane coupling agent used for the silane coupling treatment, the functional group is preferably an epoxy group. 2- (3,4-epoxycyclohexyl) ethyltrimethoxysilane, 3-glycidoxypropyltrimethoxysilane, 3-glycidoxypropylmethyldiethoxysilane, 3-glycol as silane coupling agents having an epoxy group as a functional group Sidoxypropyltriethoxysilane is preferred. These also have excellent storage stability.

The sliding layer may contain a sulfur-containing metal compound such as ZnS or Ag ₂ S as an extreme pressure agent. The sliding layer can have a surfactant, a processing stabilizer, an antioxidant, and the like.

<Sliding layer forming process>
As the sliding layer forming process, sliding with a solvent such as n-methyl-2-pyrrolidone, 1,3-dimethyl-2-imidazolidinone, xylene, etc., depending on the type of coating method such as spray coating or roll coating. It is possible to dilute the layer composition and adjust the viscosity and the solid content. It is possible to form a sliding layer by coating the base material with a diluted composition of the sliding layer composition, followed by drying and firing.

Hereinafter, Examples 1 to 16 and Comparative Examples 1 to 5 embodying the present invention will be described. First, the following materials were prepared.
Binder resin: Polyamideimide resin (PAI) varnish Solid lubricant: Particulate ultrahigh molecular weight polyethylene (UHPE particles), particulate fluorine compound (PTFE particles)
Inorganic filler: Titanium oxide Silane coupling agent

A plurality of plastic bags of the same size were prepared, and a certain amount of UHPE particles were put therein, and the inside of each bag was evacuated under the same conditions. Then, each bag was put in the electron beam irradiation apparatus, and the electron beam as a radiation was irradiated to the UHPE particle with the absorbed dose (kGy) shown in Table 1. Thus, the crosslinked product No. 1-6 UHPE particles were obtained. Uncrosslinked UHPE particles were not irradiated with an electron beam.

Table 1 shows the melting point (° C), gel fraction (%), and average particle size (μm) of each UHPE particle. Table 1 also shows the melting point (° C.) and average particle diameter (μm) of the PTFE particles.

Here, the measurement conditions of the melting point are as follows.
Analyzer: DSC Q2000 (TA instrument)
Rate of temperature increase: 5 ° C./min (After the temperature was raised to 210 ° C., it was cooled to −30 ° C. at −20 ° C./min, and measurement was performed again.)
Atmosphere: N ₂
Sample weight: 5mg ± 0.1mg each
Melting point reading condition: Melting peak temperature during re-measurement

The gel fraction was measured as follows. First, each powder was pressed at a constant pressure while being heated at 180 ° C. to 230 ° C., thereby forming a sheet having a thickness of 0.3 mm. A 0.3 g piece was cut from each sheet. Each piece was placed in a flask and 500 ml of p-xylene was added to the flask. While each flask was heated to 130 ° C., stirring was performed for 4 hours to dissolve each small piece. The solution was filtered through a wire net having a mesh size of 106 μm while maintaining a high temperature of 130 ° C. The insoluble matter on the wire mesh was dried at 140 ° C. for 3 hours under vacuum, and the weight (g) of the insoluble matter after normal temperature was measured. And the gel fraction was calculated | required by the formula of gel fraction (%) = weight (g) of an insoluble matter x100 / 0.3 (g).

As a composition preparation step, PAI varnish, solid lubricant, inorganic filler, and silane coupling agent were blended at the blending ratios shown in Tables 2 to 4, and stirred well, and then passed through a three-roll mill. 16 and compositions for sliding layers of Comparative Examples 1 to 5 were prepared. The solid lubricant is composed of PTFE particles and UHPE particles. Here, in the solid lubricant, the case of adopting PTFE particles is Comparative Example 1, the uncrosslinked product of UHPE particles is Comparative Example 2, and the crosslinked product No. 1 to 6 are any of Examples 1 to 16 and Comparative Examples 3 to 5.

The following sliding layer formation process was performed. First, each sliding layer composition is diluted with a solvent to form a diluted product. After coating each diluted product on a base material made of steel, drying is performed, and firing is performed at 220 ° C. for 1.5 hours. It was. Thereafter, surface grinding was performed to form sliding layers having a film thickness of 15 μm and 20 μm. Thus, the sliding members of Examples 1 to 16 and Comparative Examples 1 to 5 were obtained.

Each sliding member consists of a base material and a sliding layer formed on the base material. The sliding layer contains a binder resin, a solid lubricant, an inorganic filler, and a silane coupling agent. Each sliding member was subjected to the following tests 1 and 2.

<Test 1 (Ring on disk friction and wear test: in a dry environment)>
This test evaluates the wear resistance under a certain level of dry environment in the sliding layer of each sliding member. That is, as shown in FIG. 1, the sliding layer 10a of each sliding member is formed on the upper surface of the base material 10 made of S45C. The thickness of the sliding layer 10a is about 20 μm. In this state, the ring 1 is placed on the upper surface of the sliding layer 10a of each sliding member. The ring 1 made of S45C is rotated under the conditions of a surface pressure of 5.4 MPa, a sliding speed of 0.9 m / second, and a sliding distance of 500 m. During this time, the specific wear amount (× 10 ⁻⁶ mm ³ / N · m) of the sliding layer 10 a was measured. This test was performed on the sliding members of Examples 1 to 16 and Comparative Examples 1 to 5.

<Test 2 (ball-on-disk friction and wear test: in oil environment)>
This test evaluates the wear resistance under a certain level of oil environment in the sliding layer of each sliding member. That is, as shown in FIG. 2, the sliding layer 20a of each sliding member is formed on the upper surface of the base material 20 made of S45C. The thickness of the sliding layer 20a is about 15 μm. In this state, the ball 3 is placed on the upper surface of the sliding layer 20a of each sliding member. Made of SUJ2, a Φ3 / 16 inch ball 3 is rotated for a maximum of 120 seconds under the conditions of a load of 20 N and a sliding speed of 0.25 m / sec. At this time, 5 mg of the refrigerating machine oil 4 is dropped on the sliding layer 20a. During this time, the durability time until the sliding layer 20a was worn or peeled off was measured. This test was performed on the sliding members of Examples 1 to 16 and Comparative Examples 1 to 5.

The results of Test 1 and Test 2 are shown in Tables 5-7.

In evaluating the wear resistance of the sliding members of Examples 1 to 16, the sliding characteristics of the sliding member of Comparative Example 2 were used as criteria. As can be seen from Tables 2 to 4, the sliding members of Examples 1 to 16 have UHPE particles appropriately crosslinked, whereas the sliding member of Comparative Example 2 has UHPE particles crosslinked. This is because the presence or absence of crosslinking in the UHPE particles was used as a criterion.

As it can be seen from Table 5-7, each sliding members of Examples 1 to 16, if a reference the results of Test 1 in the sliding member of Comparative Example 2, the specific wear rate is 2.3 (× 10 ^{- 6} mm ³ / N · m). That is, the sliding members of Examples 1 to 16 can exhibit excellent wear resistance in a dry environment. More specifically, if the sliding layer contains titanium oxide and the melting point of the crosslinked ultrahigh molecular weight polyethylene is in the range of 126.4 ° C or higher and 132.0 ° C or lower, the sliding The wear resistance of the layer is improved.

This is because the sliding members of Examples 1 to 16 employ UHPE particles that have been irradiated with radiation in a sealed state, so that ultrahigh molecular weight polyethylene is appropriately crosslinked. For this reason, it is inferred that ultrahigh molecular weight polyethylene is unlikely to elute and drop off from the surface of the sliding layer at high temperatures. In addition, since the sliding layer appropriately has particulate titanium oxide, the titanium oxide supports the load acting between the counterpart and the sliding layer, and the ultrahigh molecular weight polyethylene is difficult to fall off. It is guessed.

On the other hand, as can be seen from Tables 5 to 7, the sliding members of Comparative Examples 1 to 3 have a specific wear amount of 2.3 (× 10 ⁻⁶ mm ³ / N · m) or more in the result of Test 1. . Therefore, the sliding members of Comparative Examples 1 to 3 are inferior in wear resistance in a dry environment as compared to the sliding members of Examples 1 to 16. The sliding member of Comparative Example 1 is presumed to be inferior in wear resistance because it employs a fluorine compound (PTFE particle) instead of a suitably crosslinked UHPE particle. Since the sliding member of Comparative Example 2 employs uncrosslinked UHPE particles having a melting point of 134.6 ° C., it is assumed that the UHPE particles are likely to elute and drop off from the surface of the sliding layer at high temperatures. Is done. This point is apparent when the sliding members of Examples 1 to 3, 9, and 10 having the same composition ratio in the sliding layer are compared with the sliding member of Comparative Example 2. Furthermore, since the sliding member of Comparative Example 3 has an absorbed dose of electron beam of 1000 kGy, it is surmised that the crosslinked UHPE particles become brittle, and the wear resistance of the sliding member deteriorates.

Therefore, in the sliding members of Examples 1 to 16, the sliding layer can exhibit excellent sliding characteristics in terms of wear resistance in a dry environment. For this reason, if these sliding members are employ | adopted for the swash plate of a compressor, it turns out that a more excellent compressor is obtained.

The ultra high molecular weight polyethylene preferably has a gel fraction of 26% or more. Also in this case, the sliding members of Examples 1 to 16 can exhibit excellent wear resistance in a dry environment. The reason for this is that ultra high molecular weight polyethylene with a gel fraction in this range is moderately cross-linked, so the friction coefficient of the sliding layer is low, the amount of wear is small, and the ultra high molecular weight from the surface of the sliding layer at high temperatures. This is probably because polyethylene is difficult to elute.

The sliding layer preferably contains a silane coupling agent. In this case, according to the test results of the inventors, it is preferable that the sliding layer contains a silane coupling agent not only in a dry environment but also in an oil environment. I know that there is. More specifically, among the sliding members of Examples 1 to 10 and Examples 14, 15, and 16 containing the silane coupling agent, the sliding members of Examples 1 to 10 do not contain the silane coupling agent. The sliding members of Examples 11 to 13 exhibit excellent wear resistance in an oil environment. That is, as can be seen from Tables 5 and 6, in the results of Test 2, in the sliding members of Examples 1 to 10, the durability time until film abrasion or film peeling exceeded 106 seconds, and the durability time was 120 seconds. Is over. Here, “> 120” shown in Tables 5 to 7 indicates that the durability time until film abrasion or film peeling exceeds 120 seconds. On the other hand, the sliding members of Examples 11 to 13 all have a durability time of 95 seconds or less until film abrasion or film peeling. From this point, it is surmised that the sliding layer containing the silane coupling agent tends to have excellent wear resistance in an oil-in-water environment. The reason for this is that the silane coupling agent strongly binds the ultrahigh molecular weight polyethylene and titanium oxide to the binder resin, so that the ultra high molecular weight polyethylene is more difficult to elute from the surface of the sliding layer at high temperatures and to be removed. Guessed. Further, the sliding members of Examples 11 to 13 can exhibit excellent wear resistance in a dry environment even if they do not contain a silane coupling agent.

In the sliding layer, it is preferable that ultra high molecular weight polyethylene is 10% by volume or more and 35% by volume or less with respect to all solid components in the sliding layer. In this case, the sliding layer can further improve the wear resistance in a dry environment. More specifically, in the result of Test 1, the specific wear amount of the sliding members of Examples 1 to 16 is less than 2.3 (× 10 ⁻⁶ mm ³ / N · m). On the other hand, the specific wear amount of the sliding members of Comparative Examples 4 and 5 greatly exceeds 2.3 (× 10 ⁻⁶ mm ³ / N · m). That is, the sliding members of Examples 1 to 16 can exhibit superior wear resistance in a dry environment as compared with the sliding members of Comparative Examples 4 and 5. In the sliding member of Comparative Example 4, since the ultra high molecular weight polyethylene is 5% by volume with respect to the total solid component in the sliding layer, it is presumed that the wear resistance effect is not sufficiently exhibited. Further, in the sliding member of Comparative Example 5, because ultra high molecular weight polyethylene is 50% by volume with respect to the total solid component in the sliding layer, UHPE particles are likely to be eluted and dropped from the surface of the sliding layer. It is guessed.

The sliding layer contains a silane coupling agent, and the silane coupling agent is preferably 0.2% by volume or more and 8% by volume or less with respect to all solid components in the sliding layer. Also in this case, the sliding layer can further improve the wear resistance in a dry environment. More specifically, in the results of Test 1, the specific wear amount of the sliding members of Examples 1 to 10 and Examples 14 to 16 is less than 2.3 (× 10 ⁻⁶ mm ³ / N · m). .

In the sliding layer, the solid lubricant is 12.0% by volume or more and 29.0% by volume or less with respect to the binder resin, and the silane coupling agent is 1% by volume or more with respect to all solid components in the sliding layer, It is preferably 5% by volume or less. In this case, the sliding layer can further improve the wear resistance in a dry environment and an oil-in-water environment. More specifically, in the sliding members of Examples 1 to 10, in the result of Test 2, the durability time until film abrasion or film peeling in the sliding member of Comparative Example 2 exceeded 106 seconds, and the durability time was further increased. Exceeds 120 seconds. As a result, the sliding members of Examples 1 to 10 can more reliably improve the wear resistance even in an oil environment. That is, the sliding members of Examples 1 to 10 can further improve the wear resistance in a dry environment and an oil-in-water environment.

In the above, the present invention has been described with reference to the first to sixteenth embodiments. However, the present invention is not limited to the first to sixteenth embodiments, and can be appropriately modified and applied without departing from the spirit of the present invention. Needless to say.

For example, in the present invention, in order to improve the adhesion between the base material and the sliding layer, it is possible to perform a degreasing step in which an alkali or the like is brought into contact with the base material. In order to further improve the adhesion between the base material and the sliding layer, it is possible to form a base layer made of a phosphate such as zinc phosphate or manganese phosphate after the degreasing step.

The present invention can be used for various sliding members.

1, 3 ... Mating material (1 ... Ring, 3 ... Ball)
10, 20 ...

Base material

10a, 20a ... Sliding layer

Claims

A sliding member that is formed on the base material and includes a sliding layer that is formed on the base material and contains a binder resin, a solid lubricant, and an inorganic filler, and the sliding layer slides on a mating material; ,
The solid lubricant is an ultra high molecular weight polyethylene having a particulate shape and a melting point of 126.4 ° C. or higher and 132.0 ° C. or lower.
The inorganic filler is particulate titanium oxide,
The said titanium oxide is 1 volume% or more and 8 volume% or less with respect to the total solid component in the said sliding layer, The sliding member characterized by the above-mentioned.
The sliding member according to claim 1, wherein the ultra high molecular weight polyethylene has a gel fraction of 26% or more.
The sliding member according to claim 1 or 2, wherein the sliding layer further contains a silane coupling agent.
The sliding member according to any one of claims 1 to 3, wherein in the sliding layer, the ultra high molecular weight polyethylene is 10% by volume or more and 35% by volume or less with respect to all solid components in the sliding layer.
The sliding layer contains a silane coupling agent,
The sliding member according to claim 4, wherein the silane coupling agent is 0.2% by volume or more and 8% by volume or less with respect to all solid components in the sliding layer.
In the sliding layer, the solid lubricant is 12.0% by volume or more and 29.0% by volume or less with respect to the binder resin.
The sliding member according to claim 5, wherein the sliding layer has the silane coupling agent in an amount of 1% by volume or more and 5% by volume or less with respect to all solid components in the sliding layer.
A manufacturing method of a sliding member for manufacturing a sliding member that slides with a counterpart material,
A crosslinking step of irradiating the particulate ultrahigh molecular weight polyethylene in a sealed state to crosslink the ultrahigh molecular weight polyethylene;
A composition preparation step for preparing a sliding layer composition comprising a solid lubricant containing the ultrahigh molecular weight polyethylene crosslinked in the crosslinking step, a binder resin, and an inorganic filler that is particulate titanium oxide. When,
A sliding layer forming step of providing a sliding member by providing the sliding layer composition on a base material to form a sliding layer that slides with the counterpart material; Manufacturing method of member.
The method for producing a sliding member according to claim 7, wherein the composition adjusting step further contains a silane coupling agent.