JP2009062935A - Sliding material composition and sliding material for swash plate of swash plate compressor - Google Patents

Abstract

To provide a sliding material composition for a swash plate of a swash plate type compressor capable of improving sliding characteristics under high speed and high load sliding conditions.
In a sliding material composition for a swash plate of a swash plate compressor, comprising a base resin and a solid lubricant,
The base resin is at least one selected from a polyimide resin and a polyamideimide resin satisfying the following formula (1), and the solid lubricant is polytetrafluoroethylene (PTFE), perfluoroethylene propene copolymer (FEP), tetra At least one selected from the group consisting of fluoroethylene / perfluoroalkyl vinyl ether copolymer resin, ethylene / tetrafluoroethylene copolymer (ETFE), polyvinylidene fluoride (PVDF), ethylene / chlorotrifluoroethylene copolymer (ECTFE) and graphite A sliding material composition for a swash plate of a swash plate compressor, characterized in that:
Y ≧ −0.76X + 200 (1)
[In the above formula (1), Y means the tensile strength (MPa) of the resin at 25 ° C., X means the elongation (%) of the resin at 25 ° C.]
[Selection figure] None

Description

  The present invention relates to a sliding material composition, and more specifically to a sliding material composition for a swash plate of a swash plate compressor.

In the swash plate sliding material composition, conventionally, a base resin as a coating composition is blended with molybdenum disulfide (MoS ₂ ), which is called a solid lubricant, PTFE, graphite, a fine hard substance, etc. as an additive, I have used it.
The coating composition has an effect of suppressing heat generation by exhibiting a low friction effect in sliding with the shoe in a lubricating state in which oil is poor such that it is lubricated only with a refrigerant during start-up rotation in an automobile compressor.
On the other hand, in situations where it is desired to rapidly cool the interior of the vehicle, such as in a high temperature environment, the compressor is in a high speed / high load sliding condition. In that case, the coating composition was accompanied by wear and peeling due to uneven wear and high load, and the surface was abruptly damaged and seized.
In order to prevent seizure, surface properties such as copper, aluminum, and tin are provided on the base material to provide an intermediate layer, and by changing the type of additive, blending amount, particle size, etc., sliding characteristics can be improved. Improvement is being studied (Patent Document 1).

JP 2005-89514 A

However, providing an intermediate layer leads to high costs. Even if the additive is changed, there is room for improvement in improving the sliding characteristics.
Then, an object of this invention is to provide the sliding material composition for swash plates of a swash plate type compressor which can improve the sliding characteristic in high speed and high load sliding conditions.

The present invention has found that the above object can be achieved by the following sliding material composition for a swash plate of a swash plate compressor.
(1) In the sliding material composition for a swash plate of a swash plate type compressor comprising a base resin and a solid lubricant,
The base resin is at least one selected from a polyimide resin and a polyamideimide resin satisfying the following formula (1), and the solid lubricant is polytetrafluoroethylene (PTFE), perfluoroethylene propene copolymer (FEP), tetra At least one selected from the group consisting of fluoroethylene / perfluoroalkyl vinyl ether copolymer resin, ethylene / tetrafluoroethylene copolymer (ETFE), polyvinylidene fluoride (PVDF), ethylene / chlorotrifluoroethylene copolymer (ECTFE) and graphite A sliding material composition for a swash plate of a swash plate compressor, characterized in that:
Y ≧ −0.76X + 200 (1)
[In the above formula (1), Y means the tensile strength (MPa) of the resin at 25 ° C., X means the elongation (%) of the resin at 25 ° C.]
(2) The swash plate slide for a swash plate compressor according to (1), wherein the base resin is at least one selected from a polyimide resin and a polyamideimide resin that further satisfy the following formula (2): Moving material composition.
Y ≧ 10000 / (X−65) (2)
[In the above formula (2), Y means the tensile strength (MPa) of the resin at 25 ° C., X means the elongation of the resin at 25 ° C.]
(3) The swash plate compressor according to (1) or (2) above, further comprising at least one selected from the group consisting of molybdenum disulfide, h-BN, tungsten disulfide, and Pb. Sliding material composition for swash plate.
(4) A sliding material for a swash plate compressor swash plate, wherein the sliding material composition according to any one of (1) to (3) is coated on a base material.

  According to the sliding material composition for a swash plate of the swash plate compressor of the present invention, by using a resin having the optimum tensile strength and elongation as a base resin, the coating layer when the composition is coated on a substrate is used. Abrasion resistance is improved and adhesion to the substrate is also increased. Thereby, the seizure resistance and the peel resistance under high speed and high load sliding conditions can be improved. Further, since the wear resistance of the coating layer is improved, the intermediate layer and the like can be eliminated, and the cost can be reduced. In the following description, PTFE will be mainly described as a representative example of a fluororesin.

  A sliding material composition for a swash plate of a swash plate compressor according to the present invention (hereinafter also referred to as a sliding material composition of the present invention) includes a base resin and a solid lubricant, and the resin has a specific tensile strength. It is characterized by being a polyimide resin or a polyamide-imide resin satisfying strength characteristics or elongation characteristics.

The base resin used in the sliding material composition of the present invention satisfies the following formula (1).
Y ≧ −0.76X + 200 (1)
[In the above formula (1), Y means the tensile strength (MPa) of the resin at 25 ° C., X means the elongation of the resin at 25 ° C.]
By satisfying the above formula (1), the tensile strength and the elongation are further optimized, and the wear resistance can be improved.

The base resin used in the sliding material composition of the present invention preferably further satisfies the following formula (2).
Y ≧ 10000 / (X−65) (2)
[In the above formula (2), Y means the tensile strength (MPa) of the resin at 25 ° C., X means the elongation of the resin at 25 ° C.]
By satisfying the above formula (2), the tensile strength and the elongation are further optimized, and the wear resistance can be improved.

  The polyimide resin and the polyamideimide resin as the base resin are required to have a certain degree of tensile strength and elongation as described above rather than having only one of tensile strength and elongation properties. The tensile strength and elongation of the resin are measured according to JIS K7127.

  The resin used for the sliding material composition of the present invention is not limited as long as it is a polyimide resin or a polyamideimide resin having the above-described tensile strength characteristics or elongation characteristics, but from the viewpoint of sliding characteristics at high temperature (particularly low friction). A polyimide resin is preferably used. Moreover, a polyimide resin or a polyamideimide resin may be used independently, and multiple types may be mixed and used.

  30-80 vol% is preferable and, as for content of the said resin in a sliding material composition, 40-70 vol% is more preferable.

  Examples of the solid lubricant used in the sliding material composition of the present invention include polytetrafluoroethylene (PTFE), perfluoroethylene / propene copolymer (FEP), tetrafluoroethylene / perfluoroalkyl vinyl ether copolymer resin, ethylene / tetra It contains at least one selected from the group consisting of fluoroethylene copolymer (ETFE), polyvinylidene fluoride (PVDF), ethylene / chlorotrifluoroethylene copolymer (ECTFE), and graphite. In the following description, polytetrafluoroethylene (hereinafter referred to as “PTFE”) will be mainly described as a representative example of a fluororesin. Polytetrafluoroethylene prevents the surface of the sliding material composition coating from becoming rough by lowering the coefficient of friction under high-speed sliding conditions. When the amount of PTFE added is increased, the friction coefficient tends to decrease. However, when the amount of PTFE is excessive, the wear resistance of the coating itself decreases and the amount of wear increases. Therefore, the amount of PTFE added is preferably 0 to 70 vol%, more preferably 5 to 30 vol%. PTFE is a calcined powder obtained by pulverizing a material once calcined at a temperature equal to or higher than the melting point, and preferably has an average molecular weight of 3 million or less.

  The graphite (graphite) may be either natural graphite or artificial graphite, but natural graphite is preferred from the viewpoint of seizure resistance, and artificial graphite is preferred from the viewpoint of wear resistance. The average particle diameter of graphite is not particularly limited, and it is preferable to use a graphite having a thickness of 0.1 to 35 μm from the relationship with the film thickness. As for the addition amount of the graphite in the sliding material composition of this invention, 0-50 vol% is preferable, More preferably, it is 5-30 vol%. If it is in the said range, it is preferable from the balance of seizure resistance and abrasion resistance being good.

As the solid lubricant, in addition to PTFE and graphite, molybdenum disulfide (MoS ₂ ), BN (boron nitride), tungsten disulfide (WS ₂ ), Pb, and the like can be used. Or it can use combining 2 or more types. In particular, molybdenum disulfide (MoS ₂ ) can be preferably used. As for the addition amount of molybdenum disulfide in the sliding material composition of this invention, 0-70 vol% is preferable, More preferably, it is 5-30 vol%. If it is in the said range, since the sliding characteristic on lubrication conditions is favorable, it is preferable.

If necessary, the sliding material composition of the present invention further includes alumina, silica, an oxide such as titanium dioxide (TiO ₂ ), a nitride such as silicon nitride, and a carbide such as silicon carbide (SiC). A sulfide such as zinc sulfide (ZnS) may be added as a hard material. Thereby, abrasion resistance improves. As the shape of the hard material, a spherical shape is desirable from the viewpoint of reducing the aggressiveness to the counterpart material. When the addition amount is too large, the wear amount of the counterpart material increases, and when it is small, the wear amount of the coating increases. The addition amount of the hard material is preferably 0 to 5 vol%, and preferably 0.1 to 2 vol%. The particle size of the hard material is preferably 0.01 to 3 μm.

  A method for forming a film with a mixture of a base resin and an additive can be, for example, a method described in JP-A-11-013638. The thickness of the coating is preferably 3 to 40 μm. The surface roughness of the coating is preferably Rz 0.5-4 μm. On the surface of the coating, ridges and grooves extending in the sliding direction may be alternately and regularly formed.

  In the present invention, the coating liquid containing the above-mentioned sliding material composition is applied on the sliding surface of the swash plate substrate (resin coating layer), and the coating is formed to provide excellent wear resistance and sliding characteristics. A swash plate compressor swash plate can be obtained.

  As the swash plate substrate, materials such as iron, copper, and aluminum can be used.

  In order to form the resin coating layer on the surface of the substrate, methods such as roll coating, spray coating, dipping, screen printing, and pad printing can be used.

  EXAMPLES The present invention will be specifically described below with reference to examples, but the present invention is not limited to these examples.

<Examples 1-1 to 1-3, Comparative Examples 1-1 to 1-4>
55% by volume of the base resin (polyimide resin or polyamideimide resin) shown in Table 1 and FIG. 1, 22.5% by volume of PTFE (made by Kitamura Co., Ltd.), 22.5% by volume of graphite (made by Nippon Graphite Co., Ltd.), and an organic solvent (NMP) ) An appropriate amount was put into a ball mill and pulverized and mixed to prepare a coating solution for forming a resin coating layer.

The obtained coating solution was coated on a swash plate substrate (iron-based) so as to have a thickness of 30 μm, and then the surface was polished so that the roughness was 6 μm Rz and the film thickness was 15 μm. Example 1-1 1 to 3 and Comparative Examples 1-1 to 1-4 were manufactured. Under the following test conditions, seizure surface pressure (MPa) and wear depth (μm) were measured. The results are shown in Table 1.
<Test conditions>
Testing machine: 3-pin / disc type seizure testing machine Rotational speed: 4000 rpm
Lubrication condition: Mist lubrication Mating shaft: SUJ2 (Shoe shape)
Load condition: 3MPa / 15min increase from preload 1MPa

  From the results shown in Table 1 and FIG. 1, the sliding material using the composition of the present invention containing the base resin satisfying the formulas (1) and (2) has remarkable seizure surface pressure and wear resistance. It is clear that there is an improvement.

<Example 2-1 and Comparative example 2-1>
60 vol% of base resin (polyimide resin or polyamideimide resin) shown in Table 2, 20 vol% of PTFE (made by Kitamura Co., Ltd.), 15 vol% of graphite (made of Nippon Graphite Co., Ltd.), 5 vol% of molybdenum disulfide (MoS ₂ ), and organic solvent (NMP) Except that an appropriate amount was used, the sliding materials of Example 2-1 and Comparative Example 2-1 were produced in the same manner as in Example 1-1. Table 2 shows the measurement results of seizure surface pressure (MPa) and wear depth (μm).

It is a graph which shows the relationship between tensile strength and elongation of resin.

Claims (4)

In the sliding material composition for a swash plate of a swash plate type compressor containing a base resin and a solid lubricant,
The base resin is at least one selected from a polyimide resin and a polyamideimide resin satisfying the following formula (1), and the solid lubricant is polytetrafluoroethylene (PTFE), perfluoroethylene propene copolymer (FEP), tetra At least one selected from the group consisting of fluoroethylene / perfluoroalkyl vinyl ether copolymer resin, ethylene / tetrafluoroethylene copolymer (ETFE), polyvinylidene fluoride (PVDF), ethylene / chlorotrifluoroethylene copolymer (ECTFE) and graphite A sliding material composition for a swash plate of a swash plate compressor, characterized in that:
Y ≧ −0.76X + 200 (1)
[In the above formula (1), Y means the tensile strength (MPa) of the resin at 25 ° C., X means the elongation (%) of the resin at 25 ° C.] 2. The sliding material composition for a swash plate for a swash plate compressor according to claim 1, wherein the base resin is at least one selected from a polyimide resin and a polyamide-imide resin further satisfying the following formula (2): .
Y ≧ 10000 / (X−65) (2)
[In the above formula (2), Y means the tensile strength (MPa) of the resin at 25 ° C., X means the elongation of the resin at 25 ° C.]   The sliding material for a swash plate for a swash plate compressor according to claim 1 or 2, further comprising at least one selected from the group consisting of molybdenum disulfide, h-BN, tungsten disulfide and Pb. Composition.   A sliding material for a swash plate compressor swash plate, wherein the sliding material composition according to any one of claims 1 to 3 is coated on a base material.

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