JPH11106775A - Solid lubricating film composition and plain bering material prepared therefrom - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a solid lubricating film compsn. improved in sliding characteristics (esp. resistances to seizure and abrasion) under boundary or mixed lubrication by compounding a thermosetting resin, a solid lubricant, and an extreme pressure agent in a specified ratio and to provide a plain bearing material prepd. from the same. SOLUTION: This compsn. contains 30-70 vol.% thermosetting resin, 20-69.7 vol.% solid lubricant, and 0.3-10 vol.% extreme pressure agent. Further addition of 10 vol.% or lower friction modifier can improve the abrasion resistance as the result of synergism with the extreme pressure agent. A polyimide resin, a polyamideimide resin, an epoxy resin. etc., can be used as the thermosetting resin. Molybdenum disulfide, graphite. etc., are solid lubricants. Examples of the extreme pressure agent are a sulfur-contg. metal compd. and an org. molybdenum compd. CrO2 , PbO, ZnO, SiC, Si3 N4 , etc.. are friction modifiers.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a solid lubricating coating composition coated on a sliding bearing material or the like in engines for automobiles and other industrial machines, and a sliding bearing material using the same.

[0002]

2. Description of the Related Art Aluminum alloys and copper-lead alloys with a Pb-based overlay are generally used as sliding bearing materials for automobile engines. In recent years, the performance of automobile engines has been remarkably improved due to high output and high rotation. The emergence of bearing materials with sliding performance is desired.

JP-A-4-83914 discloses a sliding bearing material in which a coating layer comprising a solid lubricant and a polyimide-based binder is formed on the surface of an aluminum-based bearing alloy. With such a solid lubricating coating, the initial conformability of the aluminum alloy bearing is improved,
Excellent fatigue resistance and seizure resistance are exhibited. Further, the publication describes that by replacing 1 to 20% of the solid lubricant with a friction modifier, the wear resistance of the solid lubricant film is improved.

[0004]

The solid lubricating coating containing the above-mentioned solid lubricant and binder has good seizure resistance in a normal case, but has an extremely small amount of oil and excessively no oil. Under insufficient lubrication conditions, such as when there is local oil film breakage due to one-sided or misalignment,
Severe contact with the shaft occurs, and the solid lubricating coating tends to break due to frictional heat, shear stress, and the like, resulting in a problem that sufficient sliding characteristics cannot be obtained.

SUMMARY OF THE INVENTION The present invention has been made under the above-mentioned circumstances, and provides a solid lubricating coating containing a solid lubricant and a thermosetting resin which forms a coating on the surface of a substrate even under insufficient lubricating conditions. An object of the present invention is to obtain a solid lubricating coating composition having improved sliding characteristics under mixed lubrication, and a bearing material using the same.

[0006]

According to the present invention, 30 to 70 vol% of a thermosetting resin and 20 to 69.7 v of a solid lubricant are used.
ol% and an extreme pressure agent of 0.3 to 10 vol%, by using a solid lubricating coating composition,
It was found that the sliding characteristics (particularly seizure resistance and wear resistance) under boundary / mixed lubrication were improved. Furthermore, it has been found that by containing the above-mentioned composition in an amount of 10 vol% or less of a friction modifier, abrasion resistance is further improved by a synergistic effect with an extreme pressure agent. The present invention further relates to a sliding bearing material characterized in that such a composition is coated on the surface of a bearing substrate.

Although the mechanism of action is not clear, the solid lubricating coating obtained by using the composition of the present invention causes temporary solid contact under insufficient lubricating conditions or singular contact.
It is presumed that the extreme pressure agent in which the solid lubricating film is dispersed effectively acts in a situation where the solid lubricating film is easily broken by frictional heat and shear stress at that time. That is,
The oil is held firmly by the solid lubricant and the extreme pressure agent contained in the coating, and the boundary lubrication coating is hard to break,
A smooth sliding surface is obtained, and seizure resistance and abrasion resistance under insufficient lubrication conditions are remarkably improved as compared with a conventional solid lubricating film containing a thermosetting resin without using an extreme pressure agent.

[0008]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The thermosetting resin of the present invention includes:
Examples thereof include a polyimide resin, a polyamideimide resin, an epoxy resin, and a phenol resin. Specifically, aromatic polyimide, polyetherimide, polyesterimide, or aromatic polyamideimide, or a varnish of a diisocyanate-modified, BPDA-modified, or sulfone-modified resin thereof can be used.

Examples of the solid lubricant include molybdenum disulfide (MoS ₂ ), graphite, BN, tungsten disulfide (WS ₂ ), PTFE, fluororesin, and Pb. The graphite may be either natural or artificial graphite, but artificial graphite is preferred from the viewpoint of abrasion resistance. These solid lubricants have an effect of lowering and stabilizing the coefficient of friction, and have conformability. In order to sufficiently exhibit these effects, the average particle size of the solid lubricant is preferably 15 μm or less, particularly preferably 0.2 to 10 μm.

As extreme pressure agents, ZnS, Ag ₂ S, Cu
S, FeS, FeS ₂ , Sb ₃ S ₂ , PbS, Bi ₂ S ₃ ,
Sulfur-containing metal compounds such as CdS, thiurams, morpholine disulfide, dithioates, sulfides, sulfoxides, sulfonic acids, thiophosphinates, thiocarbonates, dithiocarbamates, alkylthiocarbamoyls, sulfurized Sulfur-containing compounds such as olefins, halogen compounds such as chlorinated hydrocarbons, organometallic compounds such as thiophosphates and thiocarbamates such as zinc dithiophosphate, and organic molybdenum such as molybdenum dithiophosphate and molybdenum dithiocarbimate. And the like. The average particle size of the extreme pressure agent is preferably 5 μm or less, more preferably 2 μm or less.

The compounding amount of the thermosetting resin is 30 to 70 vol.
%, Solid lubricant 20-69.7 vol% and extreme pressure agent 0.
It is desirable to be 3 to 10 vol%. Among them, the extreme pressure agent is more preferably 1 to 5 vol%. At this amount, the solid lubricant in the solid lubricating coating containing the thermosetting resin is maintained, and sufficient seizure resistance and conformability can be obtained, and the effect of the present invention of the extreme pressure agent is effective. It is exhibited in.

In the present invention, the friction modifier may further comprise 0.3 to 1
It is preferably contained in an amount of 0 vol%. This
To improve wear resistance with friction modifiers and oil with extreme pressure agents
Work synergistically to significantly improve wear resistance.
You. As a friction modifier, CrO_Two, Fe_ThreeO_Four, Pb
O, ZnO, CdO, Al_TwoO _Three, SiO_Two, SnO_TwoSuch
Oxide, SiC, Si_ThreeN_FourSuch as compounds
be able to.

In the present invention, an appropriate amount of an organic solvent (diluent) can be contained in preparing the solid lubricating coating composition. The organic solvent is used for adjusting the viscosity to facilitate mixing, and is not particularly limited as long as it can dissolve the thermosetting resin. For example, if the resin is a polyamideimide, xylene, N-methyl-2-pyrrolidone,
100 to 3 parts by weight of toluene or the like with respect to 100 parts by weight of the composition.
00 parts by weight can be used.

In the present invention, a composition containing the above-mentioned thermosetting resin, solid lubricant, extreme pressure agent and, if necessary, a friction modifier is coated on the surface of the bearing base material.
Particularly, a sliding bearing material having excellent seizure resistance and wear resistance under insufficient lubrication conditions can be obtained.

Examples of the bearing base include metals such as copper alloys and aluminum alloys, and resins.

Although the composition of the bearing alloy is not particularly limited,
As the aluminum-based alloy, Cr, Si, Mn, Sb, Sr, Fe, Ni, M
o, Ti, W, Zr, V, Cu, Mg, Zn, etc .;
An alloy containing one or more of Sn, Pb, In, Tl, and Bi at 0% by weight or less can be preferably used. Elements of the former group mainly impart strength and wear resistance, and elements of the latter group mainly impart conformability. It is preferable to use the former and the latter in combination.

The solid lubricating film coating method will be described below. After processing a base material such as a copper alloy, an aluminum alloy, or a resin into a lining in the shape of a sliding bearing, degrease it in an alkali treatment liquid such as caustic soda, and then wash with water and hot water to remove alkali adhering to the surface. .
For example, when it is necessary to increase the adhesion of the solid lubricating film, the surface of the lining is roughened by a chemical treatment such as a combination of alkali etching and pickling after degreasing, and the lining is mechanically treated by shot blasting or the like. A method such as roughening the surface or forming irregularities on the lining surface by boring or the like can be used. If it is necessary to further improve the adhesion, the lining surface should have a thickness of 0.1 mm.
A zinc phosphate or zinc calcium phosphate conversion treatment of 1 to 5 μm may be performed. When a base treatment such as boring is combined with a chemical conversion treatment, a solid lubricating coating layer having extremely high adhesion can be obtained.

After washing with hot water and drying with warm air, the composition of the present invention diluted with a suitable diluent is applied on the lining by spraying,
Dry and sinter at 150-300 ° C. When the surface roughness after the film formation is rough, a smoothing process using a buff or the like is performed. In addition to the spray method, the solid lubricating film can be formed by a method such as a tumbling method, a dipping method, a brushing method, and a printing method. The thickness of the solid lubricating coating is preferably 1 to 50 μm.

[0019]

EXAMPLES The present invention will now be illustrated by examples, but the present invention is not limited to these examples.

Examples 1 to 5 and Comparative Examples 1 to 3 A polyamideimide resin (HPC, manufactured by Hitachi Chemical Co., Ltd.) 60 vol% as a thermosetting resin, molybdenum disulfide 37 vol% as a solid lubricant, and zinc sulfide (Zn) as an extreme pressure agent
S) 3 vol% and an appropriate amount of an organic solvent were charged into a ball mill and pulverized and mixed for 3 hours to obtain a solid lubricating coating composition of Example 1.

Next, after a bearing surface such as a cylindrical or half-cylindrical bearing in which a lining material made of an aluminum-based alloy (Al-11Sn-1.8Pb-1Cu-3Si) is pressed on a back metal steel plate, The surface was roughened by shot blasting to have a surface roughness of 4 μmRz. Next, the solid lubricating coating composition was sprayed with an air spray to a thickness of about 10 μm, and then heated and cured at 220 ° C. for about 30 minutes to form a solid lubricating coating, thereby producing a sliding bearing (Example). 1).

On the other hand, in the solid lubricating coating composition prepared in Example 1, the polyamide-imide resin (PAI) used
And molybdenum disulfide (MoS ₂ ), and if necessary, zinc sulfide (ZnS) or silver sulfide (A
Example 1 except that the amount of g ₂ S) and the amount of aluminum oxide (Al ₂ O ₃ ) as a friction modifier were changed to the composition ratio shown in Table 1 to prepare each solid lubricating coating composition. In the same manner as in the above, a solid lubricating film was formed, and each sliding bearing was manufactured.

The sliding bearing was subjected to a seizure resistance test and a wear resistance test. The results are shown in Table 1. In addition,
In the wear resistance test, 10W-30CD (manufactured by Castle) was used as a lubricating oil at an amount of 500 cc / min (oil temperature at the shaft inlet 100 ° C.) and a load of 9 kN (30 MPa) was used.
The bearing wear depth (μm) when rotating at 1 m / s (3000 rpm) for 5 hours was measured. In addition, the seizure resistance test
50W of 10W-30CD (Castle) as lubricating oil
Used at 0 cc / min, load is 1 kN every 30 minutes
The load was gradually increased (maximum 9 kN) at a speed of 7.1 m / s.

[0024]

[Table 1]

From the results shown in Table 1, it is apparent that the solid lubricating coating formed by coating the composition of the present invention has remarkably improved wear resistance and seizure resistance.

[0026]

According to the solid lubricating coating composition of the present invention,
The wear resistance and seizure resistance are remarkably improved, and a solid lubricating film having excellent sliding properties can be formed even under insufficient lubrication conditions. Furthermore, since the sliding bearing material having the solid lubricating coating of the present invention has excellent wear resistance and seizure resistance, the sliding bearing material overlay, turbo floating bush, and end are particularly useful for engines of automobiles and other industrial machines. It can be suitably used for bearings, refrigeration equipment and the like under insufficient lubrication conditions.

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁶ Identification code FI C10N 10:04 10:06 10:12 40:02 (72) Inventor Yasunori Kabuya 3-65 Midorigaoka, Toyota City, Aichi Prefecture Inside the corporation

Claims (3)

[Claims] 1. A thermosetting resin of 30 to 70 vol%, a solid lubricant of 20 to 69.7 vol% and an extreme pressure agent of 0.3 to 10
A solid lubricating coating composition characterized by containing vol%. 2. The solid lubricating coating composition according to claim 1, further comprising 10% by volume or less of a friction modifier. 3. A sliding bearing material comprising a bearing substrate surface coated with the solid lubricating coating composition according to claim 1 or 2.