KR20140044778A - Sliding material composition and sliding member - Google Patents

Abstract

It is an object of the present invention to provide a sliding material composition and a sliding member that can achieve low friction at start-up and sliding even when the other sliding member is rubber. The present invention relates to a sliding material composition wherein the other sliding member is used for a sliding member composed of rubber, comprising: binder resin, 5 to 25% by volume of Nω-monoacyl basic amino acid, 5 to 25% by volume of molybdenum disulfide, and 5 to 20 volume percent polytetrafluoroethylene.

Description

SLIDING MATERIAL COMPOSITION AND SLIDING MEMBER

The present invention relates to a sliding material composition and a sliding member, and more particularly, to a sliding material composition in which the other sliding material is suitable for a sliding member composed of rubber.

Conventionally, in order to realize lubrication in the sliding part of machinery, the technique which coats the sliding material composition on the surface of each sliding part so that it functions as a lubricating film in a sliding part is implemented. Therefore, this kind of sliding material composition is required to be a lubricating film having low friction, excellent wear resistance so that wear does not occur even after long-term use, and good compatibility with the other sliding material.

As a conventional sliding material composition, the sliding material composition (refer patent document 1) containing a binder resin, a solid lubricant, and Nω-monoacyl basic amino acid, a heat resistant resin, a fluororesin, a solid lubricant, for example And a sliding material composition (see Patent Document 2) containing an organopolysiloxane and an organic solvent are known.

Japanese Patent Publication No. 2004-10707 Japanese Patent Publication No. 08-109352

The sliding material composition described in Patent Literature 1 is low friction and excellent in wear resistance under sliding conditions under no lubricating flow conditions, that is, under dry conditions without fluid lubrication such as oil and grease. However, under mixed lubrication conditions, i.e., under conditions where fluid lubrication (lubrication in an oil or grease-free environment) and boundary lubrication (lubrication in an oil or grease-free environment) may occur, in particular, the other sliding member may be a rubber-based material. In case of the friction coefficient is large.

In addition, the sliding material composition described in Patent Document 2 does not reduce the adhesion, the friction coefficient and the sintering resistance of the coating, but it is not possible to achieve a reduction effect of the friction coefficient at start-up and insufficient wear resistance.

An object of the present invention is to provide a sliding material composition and a sliding member that can attain low friction at start-up and sliding movement, particularly when the other sliding member is a rubber-based material.

In view of the above problems, the present inventors have a low frictional effect by lowering the static friction coefficient because the rubber, which is an elastic body, has high hysteresis and has a high static friction coefficient at the start of sliding in the sliding movement of the rubber-based material. It was found that can be obtained, and obtained the knowledge about the wear resistance to complete the present invention. That is, this invention relates to the sliding material composition and the sliding member of the following structure.

(1) A sliding material composition wherein the opposite sliding member is used for a sliding member composed of rubber, the sliding material composition comprising: a binder resin; 5-25% by volume of Nω-monoacyl basic amino acid; 5 to 25 volume percent molybdenum disulfide; And 5 to 20% by volume of polytetrafluoroethylene. Sliding material composition comprising a.

(2) The sliding material composition according to the above constitution (1), wherein the ratio of the content of the polytetrafluoroethylene to the content of the molybdenum disulfide is 0.5 to 2.0 on a volume basis.

(3) In the above configuration (1) or (2), when the total content of the molybdenum disulfide and polytetrafluoroethylene is X and the content of the Nω-monoacyl basic amino acid is Y, A sliding material composition, wherein the ratio of X satisfies a relationship of 2 ≦ X / Y ≦ 3 on a volume basis.

(4) The fluorine resin according to any one of the above (1) to (3), except for graphite, tungsten disulfide, mica, and polytetrafluoroethylene. A sliding material composition further comprising up to 10% by volume of at least one solid lubricant selected from the group consisting of boron nitride, graphite fluoride, and fullerene.

(5) At least one selected from the group consisting of SiC, alumina, Si ₃ N ₄ , TiO ₂ , SiO ₂ , calcium carbonate, barium sulfate, and calcium phosphate in any one of the above structures (1) to (4). A sliding material composition further comprising one kind of inorganic additive.

(6) The composition of any of the above (1) to (5), wherein the binder resin is a polyamideimide resin, a polyimide resin, a phenol resin, a polyacetal resin, a polyether ether ketone resin, and a polyphenylene sulfide It is at least 1 sort (s) of resin chosen from the group which consists of resin, The sliding material composition characterized by the above-mentioned.

(7) A sliding member in which the other sliding member is made of rubber, the sliding member comprising a base material and a coating layer: the base material is steel, stainless steel, cast iron, copper, copper alloy, aluminum, aluminum alloy, rubber, plastic, and ceramic It is formed of a material selected from the group consisting of; The coating layer is installed on the surface of the substrate, the coating layer is: binder resin, 5 to 25% by volume of Nω- monoacyl basic amino acid, 5 to 25% by volume of molybdenum disulfide, and 5 to 20% by volume of polytetrafluoro Ethylene, a sliding member comprising: a.

(8) The sliding member according to the above (7), wherein in the coating layer, the ratio of the content of polytetrafluoroethylene to the content of the molybdenum disulfide is 0.5 to 2.0 on a volume basis.

(9) In the above configuration (7) or (8), in the coating layer, when the total content of the molybdenum disulfide and polytetrafluoroethylene is X and the content of the Nω-monoacyl basic amino acid is Y And a ratio of X to Y satisfies a relationship of 2 ≦ X / Y ≦ 3 on a volume basis.

(10) The composition according to any one of the above (7) to (9), wherein the coating layer is fluorine resin, boron nitride, graphite fluoride, and fullerene except graphite, tungsten disulfide, mica, and polytetrafluoroethylene. A sliding member comprising at least 10% by volume of at least one solid lubricant selected from the group consisting of:

(11) The composition according to any one of the above (7) to (10), wherein the coating layer is selected from the group consisting of SiC, alumina, Si ₃ N ₄ , TiO ₂ , SiO ₂ , calcium carbonate, barium sulfate, and calcium phosphate A sliding member comprising at least one inorganic additive selected.

(12) The composition according to any one of the above (7) to (11), wherein the binder resin is a polyamideimide resin, a polyimide resin, a phenol resin, a polyacetal resin, a polyether ether ketone resin, and a polyphenylene sulfide It is at least 1 type of resin chosen from the group which consists of resin, The sliding member characterized by the above-mentioned.

(13) The sliding member according to any one of the configurations (7) to (12), wherein the counterpart sliding member is a sealing component for a vehicle hub bearing portion.

According to the present invention, in particular, when the other sliding member is a rubber type, it is possible to provide a sliding material composition and a sliding member that can achieve low friction at start-up and sliding, and also excellent in wear resistance.

1 is a schematic diagram of a reciprocating slip tester used in the examples.
2A and 2B are schematic views of a friction torque tester used in the embodiment, FIG. 2A is a schematic top view of the tester, and FIG. 2B is a schematic cross-sectional view of the bearing used for the test.
3 is a graph showing the results of the friction torque test.

The sliding material composition according to the present invention (hereinafter referred to as "composition of the present invention") is composed of binder resin, 5-25% by volume of Nω-monoacyl basic amino acid, 5-25% by volume of molybdenum disulfide, 5-20% by volume Polytetrafluoroethylene (PTFE).

Binder resin is a material having a function of binding (or binding) the composition of the present invention, polyamideimide (PAI) resin, polyimide resin, phenol resin, polyacetal resin, polyether ether ketone resin, and polyphenylene sulfide At least 1 type of resin chosen from the group which consists of resin is preferable. Among these resins, it is preferable to use a polyamideimide (PAI) resin from the viewpoint of wear resistance.

The composition of the present invention contains three types of solid lubricants consisting of Nω-monoacyl basic amino acids, molybdenum disulfide, and PTF in a specific amount.

In the sliding motion with respect to the counterpart material made of rubber, when a part starts to move, it shifts from the static friction coefficient to the dynamic friction coefficient, and thus the sliding motion is affected by a lubricant having a low friction coefficient among the lubricants blended. easy. On the contrary, in the case of the slippery in which the counterpart material becomes a rigid material, the friction coefficient does not shift to the dynamic friction coefficient until the whole is started, and therefore, the lubricant having high friction coefficient among the lubricants to be blended is easily affected. In view of such a phenomenon, the composition of the present invention contains three types of solid lubricants. The first solid lubricant lowers the static friction coefficient at startup. The second solid lubricant can lower the coefficient of kinetic friction and achieve wear resistance. The third solid lubricant reduces the coefficient of kinetic friction in the absence of grease, i.e. without lubrication. In the present invention, as the first solid lubricant, Nω-monoacyl basic amino acid which is an amino acid-based solid lubricant, molybdenum disulfide (MoS ₂ ) as the second lubricant, and PTFE as the third lubricant are employed.

Specific examples of the Nω-monoacyl basic amino acid include Nε-lauloryl-L-lysine. Nε-laurylyl-L-lysine is characterized by low friction. Thus, Nε-lauryll-L-lysine may be bound to the binder resin to obtain a low friction coating composition. Since Nε-lauryll-L-lysine has a lower strength than PTFE or the like, when solid lubricants such as PTFE coexist, the decrease in wear resistance can be suppressed. In addition, during the sliding motion, a composite layer of Nε-lauloryl-L-lysine and a solid lubricant is formed between the other axis and the sliding surface, thereby reducing friction. As the friction decreases, the exothermic temperature of the sliding surface is suppressed, and thus damage to the resin composition and the composition transfer layer is also suppressed. As a result, excellent wear resistance can be achieved.

However, since N omega -monoacyl basic amino acid alone is not enough to maintain oil in grease, a low friction effect can be exhibited by using molybdenum disulfide with good oil retention, and wear resistance is also improved. In addition, when the oil is excluded from the composition, a low frictional effect can be expected because the lubricating component is supplemented by blending PTFE. Under grease lubrication, the oil is replenished or depleted by sliding or the like. Thus, by adding both molybdenum disulfide and PTFE, low friction and abrasion resistance effects can be exhibited with or without oil.

In the present invention, the Nω-monoacyl basic amino acid can be easily obtained by introducing a hydrophobic acyl group into the ω basic amino acid. Examples of basic acrylic acid constituting the Nω-monoacyl basic amino acid used in the present invention include lysine, ornithine, and the like, and these may be optically active substances or racemic bodies. As the acyl group, a saturated or unsaturated aliphatic acyl group having 8 to 22 carbon atoms is preferable. Preferred specific examples of the Nω-monoacyl basic amino acid include Nε-lauloryl-L-lysine.

The content of Nω-monoacyl basic amino acids in the composition is 5 to 25% by volume, preferably 5 to 15% by volume. If the content of Nω-monoacyl basic amino acid is within the above range, a good initial low friction effect can be obtained.

Content of molybdenum disulfide in the composition of this invention is 5-25 volume%, Preferably it is 5-15 volume%. If the content of molybdenum disulfide is in the above range, good wear resistance can be obtained.

The average particle size of molybdenum disulfide is preferably 0.5 µm to 20 µm, more preferably 1 µm to 10 µm.

In the composition of the present invention, the content of polytetrafluoroethylene (PTFE) is 5 to 20% by volume, preferably 5 to 15% by volume. If the content of PTFE is in the above range, good low friction effect can be obtained.

In addition, the average particle size of PTFE is preferably 0.5 µm to 20 µm, and more preferably 1 µm to 10 µm.

In addition, it is preferable that content ratio (rate) of PTFE with respect to content of molybdenum disulfide is 5-2.0 by volume basis. When the ratio (ratio) is 0.5 or more, the oil in the grease is sufficiently maintained, the friction can be reduced, and excellent wear resistance can be expanded. Moreover, when the said ratio (ratio) is 2.0 or less, since the coefficient of friction is hard to increase even when the oil in grease runs out, it is preferable.

Moreover, it is preferable that the ratio (rate) when the total content of molybdenum disulfide and PTFE is X and the content of Nω-monoacyl basic amino acid is Y satisfies the relationship of 2 ≦ X / Y ≦ 3 on a volume basis. . When X / Y is 2 or more, it is preferable because oil retention in grease is sufficient and a friction coefficient can be reduced. Moreover, when X / Y is 3 or less, since the low friction effect of N omega-monoacyl basic amino acid becomes sufficient and a friction coefficient can be reduced, it is preferable.

The composition of the present invention may contain a solid lubricant except for the above-mentioned solid lubricant in view of imparting low friction, or may contain an inorganic additive in view of imparting wear resistance.

At least one solid lubricant selected from the group consisting of graphite, tungsten disulfide, mica, fluorine resin, boron nitride, graphite fluoride, and fullerene except PTFE is preferable. . In addition, from the viewpoint of low friction, the content of the solid lubricant in the composition is preferably 10% by volume or less.

As the inorganic additive, at least one inorganic additive selected from the group consisting of SiC, alumina, Si ₃ N ₄ , TiO ₂ , SiO ₂ , calcium carbonate, barium sulfate, and calcium phosphate is preferable. In addition, from the viewpoint of wear resistance, the content of the inorganic additive in the composition is preferably 1 to 5% by volume.

The sliding material composition according to the present invention can be used as a coating layer on the substrate surface of the sliding member. In particular, the sliding material of the present invention is suitable for coating on sliding surfaces when the other sliding member is rubber. As a specific example as a counter slide member, the sealing part of the hub bearing part for automobiles is mentioned.

The material of the substrate in the sliding member according to the present invention is not particularly limited, but a material selected from the group consisting of steel, stainless steel, cast iron, copper, copper alloy, aluminum, aluminum alloy, rubber, plastic, and ceramic is preferable. . In addition, the shape of the base material is not particularly limited, but may be a plate or tubular shape.

As a method of forming the coating layer, for example, a method of mixing the composition of the present invention with a solvent of a resin, forming a film by a known method such as air spray coating, and then firing the film formed at the baking temperature of the resin may be applied. . In addition, in order to strengthen the coating, a roughening treatment may be performed before coating the substrate surface, and an adhesive layer may be provided between the substrate and the coating layer. It is preferable that the thickness of a coating layer is 5 micrometers-30 micrometers. The surface roughness (roughness) of the coating layer is not particularly limited, but 0.3 µm Ra to 3 µm Ra is preferable.

The lubrication conditions of the sliding member according to the present invention are not particularly limited, but any of oil lubrication, grease lubrication, and no lubrication can be used.

Example

<Examples 1-9, Comparative Examples 1-7>

After shot blasting treatment was performed on the SUS substrate (thickness about 0.8 mm), spray coating (coating) was performed to a thickness of about 15 μm using the composition shown in Table 1 below. In addition, Nε-laurylyl-L-lysine used Amihope LL (trademark) of Ajinomoto Co., Ltd., and HPC-5300 of Hitachi Chemical Co., Ltd. was used for polyamideimide (PAI) resin. The average particle size of graphite was 1 μm, and the average particle size of molybdenum disulfide was 1.0 μm. After the film formation by spray coating (coating), the obtained film was baked at 200 ° C. to prepare a sample.

Reciprocating slip tests were performed on each sample in Examples and Comparative Examples, and the coefficient of friction and the amount of wear were measured. Moreover, the friction torque test was done about the sample of Example 5. The results of the reciprocating slip test are shown in Table 1 and the results of the friction torque test are shown in FIG. 3.

<Round slide test>

Tester: Reciprocating Slip Tester (FIG. 1)

Load: 9.8N

Stroke: 5mm

Frequency: 5 Hz

Round trip: 200 times

Temperature: room temperature

Lubrication: Grease Coated

Speed: 50m / s

Material of counterpart sliding member: rubber (NBR)

The results of the test are shown in Table 1 below.

Composition ratio (% by volume) Coefficient of friction Wear amount
(탆) PAI Epoxy resin Nω-laurylyl-L-lysine MoS ₂ PTFE black smoke SiC Maximum Friction Coefficient at Startup Coefficient of friction

room
city
Yes



One 64 - 25 5 5 - One 0.15 0.08 2.1 2 60 - 20 10 10 - - 0.13 0.06 1.5 3 62 - 15 8 10 5 - 0.14 0.07 1.8 4 60 - 10 10 20 - - 0.12 0.05 1.3 5 70 - 10 10 10 - - 0.10 0.04 1.0 6 60 - 10 20 10 - - 0.13 0.05 1.2 7 75 - 5 10 10 - - 0.15 0.09 1.5 8 70 - 10 15 5 - - 0.30 0.13 3.2 9 60 - 20 5 15 - - 0.31 0.12 3.5

ratio
School
Yes

One 60 - - 20 20 - - 0.38 0.15 4.7 2 80 - - - 10 10 - 0.44 0.15 5.6 3 57 - 3 20 20 - - 0.25 0.11 4.5 4 60 - 40 - - - - 0.52 0.20 15.0 5 - 60 - 20 10 10 - 0.49 0.23 8.3 6 80 - - 10 5 5 - 0.27 0.15 8.3 7 70 - 10 20 - - - 0.20 0.12 4.0

When the composition of the Example was used, it can be confirmed that the friction coefficient at the time of starting and sliding is low and also excellent in abrasion resistance.

Wear Torque Test

When the bearing rotation speed was changed in the range of 100 rpm to 800 rpm using the tester shown in FIGS. 2A and 2B, and the slip material composition of Example 5 was used, and the slip material composition was not used (i.e., only The effect of reducing torque under grease lubrication was compared with that of SUS alone).

The test results are shown in FIG.

In the case of using the sliding material composition of Example 5, the friction torque reduction effect of up to 4.5% was obtained at 400 rpm.

While the invention has been described in detail and with reference to specific embodiments thereof, it will be apparent that various changes and modifications can be made by those skilled in the art without departing from the spirit and scope of the invention.

This application is based on the JP Patent application (application 2011-032811) of an application on February 18, 2011, The content is taken in here as a reference.

Claims (13)

A sliding material composition wherein the other sliding member is used in a sliding member composed of rubber, the sliding material composition comprising:
Binder resin;
5-25% by volume of Nω-monoacyl basic amino acid;
5 to 25 volume percent molybdenum disulfide; And
5 to 20% by volume polytetrafluoroethylene;
&Lt; RTI ID = 0.0 &gt;
Slip material composition. The method of claim 1,
The ratio of the content of the polytetrafluoroethylene to the content of the molybdenum disulfide is 0.5 to 2.0 on a volume basis
Slip material composition. 3. The method according to claim 1 or 2,
When the total content of the molybdenum disulfide and polytetrafluoroethylene is X and the content of the Nω-monoacyl basic amino acid is Y, the ratio of X to Y is 2 ≦ X / Y ≦ 3 on a volume basis Characterized in that
Slip material composition. 4. The method according to any one of claims 1 to 3,
10% by volume or less of at least one solid lubricant selected from the group consisting of fluorine resin, boron nitride, graphite fluoride, and fullerene except graphite, tungsten disulfide, mica, and polytetrafluoroethylene By
Slip material composition. 5. The method according to any one of claims 1 to 4,
Further comprising at least one inorganic additive selected from the group consisting of SiC, alumina, Si ₃ N ₄ , TiO ₂ , SiO ₂ , calcium carbonate, barium sulfate, and calcium phosphate
Slip material composition. The method according to any one of claims 1 to 5,
The binder resin is at least one resin selected from the group consisting of polyamideimide resin, polyimide resin, phenol resin, polyacetal resin, polyether ether ketone resin, and polyphenylene sulfide resin.
Slip material composition. A sliding member of which the opposite sliding member is made of rubber, the sliding member comprising a substrate and a coating layer:
The substrate is formed of a material selected from the group consisting of steel, stainless steel, cast iron, copper, copper alloy, aluminum, aluminum alloy, rubber, plastic, and ceramic;
The coating layer is installed on the surface of the substrate, the coating layer is:
Binder resin,
5-25 volume% Nω-monoacyl basic amino acid,
5 to 25 volume percent molybdenum disulfide, and
5-20% by volume polytetrafluoroethylene,
&Lt; RTI ID = 0.0 &gt;
Non-slip member. 8. The method of claim 7,
In the coating layer, the ratio of the content of polytetrafluoroethylene to the content of the molybdenum disulfide is 0.5 to 2.0 on a volume basis
Non-slip member. 9. The method according to claim 7 or 8,
In the coating layer, when the total content of the molybdenum disulfide and polytetrafluoroethylene is X and the content of the Nω-monoacyl basic amino acid is Y, the ratio of X to Y is 2 ≦ X / Satisfying a relationship of Y≤3
Non-slip member. 10. The method according to any one of claims 7 to 9,
The coating layer contains 10% by volume or less of at least one solid lubricant selected from the group consisting of fluorine resin, boron nitride, graphite fluoride, and fullerene except graphite, tungsten disulfide, mica, and polytetrafluoroethylene. Characterized by
Non-slip member. 11. The method according to any one of claims 7 to 10,
The coating layer comprises at least one inorganic additive selected from the group consisting of SiC, alumina, Si ₃ N ₄ , TiO ₂ , SiO ₂ , calcium carbonate, barium sulfate, and calcium phosphate.
Non-slip member. 12. The method according to any one of claims 7 to 11,
The binder resin is at least one resin selected from the group consisting of polyamideimide resin, polyimide resin, phenol resin, polyacetal resin, polyether ether ketone resin, and polyphenylene sulfide resin.
Non-slip member. 13. The method according to any one of claims 7 to 12,
The other sliding member is a sliding member, characterized in that the sealing component of the hub bearing portion for a vehicle.

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