JPS5945006B2 - sliding friction material - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a smooth friction material having excellent wear resistance, corrosion resistance, etc.

Conventional sliding friction materials that use synthetic resin on the bottom side include those that coat a steel backing plate with synthetic resin, dry and sinter it, and those that coat a steel backing plate with metal powder such as copper or copper alloy. sintered and the sintered porous layer is impregnated with synthetic resin, or synthetic resin alone (solid)
It is generally known to use directly as a friction material.

However, among these friction materials, the above-mentioned first and second materials that use backing metals are difficult to maintain electrical insulation between two members that slide relative to each other or are in contact with each other. , cannot be used when it is necessary to provide electrical insulation function between the bearing and the housing, etc.

2. Cannot be used in a corrosive atmosphere where the metal backing will corrode.

3 When used in a bearing and the bearing is used in a ferromagnetic environment, eddy currents are generated in the bearing, increasing the apparent frictional force, and the magnetic field causes wear particles such as iron powder to be transferred to the sliding surface. As a result of adhesion, abrasive wear may occur.

4. Weight increases.

Due to these drawbacks, it is not possible to use a flat friction material with a steel backing plate as a flat friction material that requires insulation and corrosion resistance, or as a flat friction material that is used under a strong magnetic field. .

On the other hand, materials made of synthetic resin alone have no problems with the above-mentioned insulation properties and corrosion resistance, but they generally have lower load resistance than materials that use backing steel plates, so they cannot be used as sliding friction materials. The disadvantage is that the cost is high because it requires a certain thickness, and the initial fit is poor. In view of the above circumstances, the present invention addresses the above-mentioned drawbacks of synthetic resin sliding friction materials having a backing metal, namely, poor insulation resistance and corrosion resistance, difficulty in use under strong magnetic fields, and large weight. The purpose of this product is to eliminate the shortcomings such as friction materials that are made of synthetic resin alone, and to improve the shortcomings of poor initial fitting and low load-bearing properties, which are the shortcomings of smooth friction materials made of a single synthetic resin. By using a heat-resistant reinforced plastic in which fibers or carbon fibers are impregnated with an adhesive resin such as polyimide resin or epoxy resin, the load-bearing capacity is improved, and the material has good conformability and smoothness to the surface of the base material. The above-mentioned drawbacks are solved by coating with a resin mixture.

The slip-on friction material according to the present invention is made of adhesive resin of 10 to 35% by weight and 5 to 30% of adhesive resin on heat-resistant reinforced plastic.
of an aromatic polyester resin and the remainder is a tetrafluoroethylene resin, or a mixture containing an adhesive resin and an aromatic polyester resin in the above proportions, and further contains 1 to 15% of the aromatic polyester resin.
% of one or more solid lubricants and the remainder is tetrafluoroethylene resin, which is then coated, dried, and fired. As the adhesive resin, polyamide-imide resin, polyimide resin, etc. are preferable, and the reason for using this is to strengthen the adhesion and adhesion with the heat-resistant reinforced plastic. The amount of this added is 3
If it exceeds 5%, the tetrafluoroethylene resin component will be relatively small and the excellent low friction properties of the tetrafluoroethylene resin will not be fully exhibited, and if it is less than 10%, the adhesion with heat-resistant reinforced plastics will decrease. decreases. Next, the aromatic polyester resin is added to improve heat resistance and abrasion resistance, and to take advantage of the low friction properties of the aromatic polyester resin itself, and the amount added is preferably 5 to 35%. .

The reason for this is that when the amount added exceeds 35%, the amount of the tetrafluoroethylene resin component decreases and its excellent low friction properties cannot be fully demonstrated, while when the amount is less than 5%, the excellent low friction properties of the aromatic polyester resin are reduced. This is because wear resistance etc. cannot be exhibited. Further, the solid lubricant was added to make the synergistic effect between the tetrafluoroethylene resin and the aromatic polyester resin more pronounced.

In other words, solid lubricants such as molybdenum disulfide (MOS2), lead (Pb), and graphite (Gr) themselves have low friction properties, and by adding them, they can improve compatibility and lipophilicity. It can be improved. If the amount added is less than 1%, no effect can be expected, and if it exceeds 15%, the coating film will become weak, so it should be 1 to 15%.
% is desirable. In addition, this solid lubricant is not only one type,
A mixture of two or more types can be used. In addition, the remainder,
That is, the reason why tetrafluoroethylene resin is used as the main component is to take advantage of the low friction properties of this resin as described above.

The sliding friction material of the present invention is obtained by coating a heat-resistant reinforced plastic with a mixture having the above composition, drying and firing it as described above. By applying an undercoat with a mixture of adhesive resin and tetrafluoroethylene resin, stronger adhesion between the coated resin and the heat-resistant reinforced plastic can be obtained, and oil pockets can also be provided on the coated resin surface. If so,
A very friction material with extremely low friction and no need for lubrication and maintenance can be obtained.

In addition, when applying the above-mentioned undercoat, the film thickness of 11ζ is 0.00
It is desirable to set it to about 5 to 0.010 fins. Next, the present invention will be explained based on examples.

Example 1 (Samples 7f6.1, 2, 3) Sheet material made of glass fiber or carbon fiber impregnated with polyimide resin (
The plastic (hereinafter referred to as heat-resistant reinforced plastic) is sanded, washed with water, and then dried at 90 to 100° C. for 30 minutes to remove moisture.

Next, polyamide-imide resin (abbreviated as PAI in Table 1), aromatic polyester resin, and tetrafluoroethylene resin (remainder, abbreviated as 4F in Table 1) were mixed in the proportions shown in Table 1. This was spray coated onto a heat-resistant reinforced plastic, dried at 90 to 100°C for 30 minutes to evaporate the solvent, and further baked at 280°C for 30 minutes to obtain a sliding friction material. Example 2 (sample 7V). 4
, 5, 6) After sanding the heat-resistant reinforced plastic and washing with water,
Dry at 0 to 100°C for 30 minutes to remove moisture.

Next, polyamideimide resin (PA in Table 1) was used as an undercoat.
Spray coating a mixture of (abbreviated as I) and tetrafluoroethylene resin (abbreviated as 4F) in the proportions shown in Table 1,
Dry at 90-100°C for 30 minutes. This heat-resistant reinforced plastic, which has been undercoated, is coated with a first coat of polyamide-imide resin, aromatic polyester resin, and tetrafluoroethylene resin.
Spray coat the mixture in the proportions shown in the table and
After drying at ~100°C for 30 minutes to evaporate the solvent, it was further baked at 280°C for 30 minutes to obtain a sliding friction material. Example 3 (Sample/F6.7, 8, 9) The mixing ratio of the synthetic resin mixture to be coated on the heat-resistant reinforced plastic was as shown in Table 1, and MOS2, Pb, and Gr were added in the ratios shown in the same table. A Veri friction material was prepared in the same manner as in Example 1 by adding one or two of the following.

Example 4 (Sample washing 10, 11, 12) Undercoating was performed in the same manner as in Example 2 using the mixture in the proportions shown in Table 1, and then one of MOS2, Pb, and Gr was added in the proportions shown in the table. The resulting mixture was spray coated in the same manner as in Example 2 to produce a sliding friction material.

Example 5 (Sample.7V). 13, 14, 15) An oil pocket A as schematically shown in FIG. 1 was provided in a slip friction material prepared in the same manner as in Example 1.

In the figure, B is a synthetic resin coating layer, C is a heat-resistant reinforced plastic, and D is grease held in an oil pocket A. Table 1 shows the above Examples 1 to 5 (sample Af
) 1 to *<15) The composition of the synthetic resin coated on the samples and the sample Al) as a comparison material. The compositions of Nos. 16 and 17 are shown.

However, sample 7f6.16 is a simple substance of tetrafluoroethylene resin (
The sample waste 17 is made by sintering a copper alloy on a back metal plate and impregnating the porous layer with tetrafluoroethylene resin. Next, Table 2 shows the results of a sliding friction test (Experiment 1) performed on each of the above samples, and the experimental conditions are as follows.

Experimental conditions〉 Testing machine: Pin/disk type high-speed sliding friction tester Mating material: MO-based alloy Surface pressure: 101<9/Cd Sliding speed: 40 m/s Lubricating: None (However, Example 5 (sample. 46 .13, 14
, 15), grease is retained in the oil pocket.

) The experimental results shown in Table 2 show that the sliding friction material according to the present invention has good friction properties, with both the friction coefficient and wear rate being equal to or lower than those of the comparative material. , and also clarifies the reasons for limiting the mixing ratio of each resin, etc.

That is, first, the mixing ratio of polyamide-imide resin is 4%.
Sample wash 1, which is , peeled off, but if this exceeds 10%, it usually does not peel off, although it depends on the conditions of use. Another sample. /
As shown by F6.3, when the mixing ratio of this resin exceeds 35% to 40%, the coefficient of friction increases. Next, for aromatic polyester resins, as sample No. 5 shows, when the wear amount is less than 5%, an increase in the amount of wear is observed, and as sample /16.6 shows, when it exceeds 35%, the friction coefficient becomes high. Regarding the solid lubricant, Sample 9 with 20% Gr added peeled off, which proves that adding too much will weaken the coating. In addition, in this experiment, in terms of the presence or absence of peeling, Examples 2 and 4 (undercoated)
sample. 46.4-6, 10-12) and Examples 1 and 3 (Samples 1-3, 7-9) in which no undercoat was applied, but the heat-resistant reinforced plastic was better with the undercoat. It is clear that the adhesion strength with the material increases. In addition, Example 5 (sample washes 13 to 15), which was provided with an oil pocket, was found to have a low coefficient of friction, and sample A6. Since no peeling was observed in l3, it was confirmed that lubrication by oil pockets was effective. Furthermore, in terms of cost, if a sample of the same shape is made using the slip friction material according to the present invention and the solid material of the sample washing 16, the solid material will be more expensive. (Experiment 2) Corrosion resistance tests were conducted on samples washed 2, 4, 9, 12, and 17 by immersing them in oil under the following conditions.

FIG. 2 shows the results of Experiment 2, showing how quickly the sample weight decreased.

However, the weight of each sample before the test is 7.2y for sample A6.2.
．． Waterfall 4 is 7.17, Waterfall 9 is 7.27, /F6. l2 is 7
．． 07, wash 17 is 35.47. As this graph shows, the sliding friction material according to the present invention exhibits almost no weight loss, whereas the comparison material Sample Taki 17 shows a significant weight reduction.

This is because the sample washer 17 uses a steel plate as a backing metal. In addition, sample /F6. The adhesion strength of the synthetic resin film layer of No. 17 was extremely reduced, and a phenomenon of peeling was observed in some parts of the sample. As described above, the sliding friction material of the present invention has much better corrosion resistance than materials using a backing metal, and also has the advantage of being lightweight since it does not require a backing metal. (Experiment 3) A friction test was conducted on Samples A6.2, A6.2, A6.4, and A6.17 under the following conditions in order to particularly investigate the wear characteristics under a magnetic field.

(Experiment conditions) Testing machine: Mechanical testing site type friction and wear tester Mating material: permanent magnet (MCAl5O) Surface pressure: 10k9/Cd Slip speed: 1.5m/Sec Lubricating: In oil bath (however, less than 200 meshes of Fe2O3 Figure 3 shows the results of Experiment 3 above, showing how much the sample weight decreased.The weight of each sample before the test was , 46.2 is 7.37, wash 4 is 7.2y, . ．．
/F6. l7 was 35.27.

As is clear from this graph, the weight of sample Taki 17 using a backing steel plate decreases due to sharp curves as the test time passes, whereas the friction material according to the present invention (sample 716
2 and 4) have less weight loss, and the difference in weight loss between the two becomes larger as time passes. This is because the permanent magnet (MCAl5O), which is the material to be tested in the friction test, is Fe2O3 in an oil bath.
Sample A6. has a steel backing plate to trap powder. This can be interpreted as indicating that abrasive wear caused by this Fe2O3 powder is caused in 17, whereas the friction material of the present invention uses heat-resistant reinforced plastic, so there is less abrasive wear due to the entrainment of Fe2O3 powder. .
As explained above, the sliding friction material according to the present invention has a lower wear rate and coefficient of friction than conventional friction materials using a backing steel plate or friction materials made of a single synthetic resin, and is also cheaper in cost. Since the substrate is made of heat-resistant reinforced plastic, it has excellent corrosion resistance and is lightweight.

Furthermore, since there is little abrasive wear due to entrainment of iron powder under a magnetic field, it is advantageous as a sliding friction material used under a magnetic field, and insulation between sliding members can be easily obtained, so it can be used for shafts that require insulation. It can be used for an extremely wide range of applications, including bearings, shafts, and housings.

[Brief explanation of the drawing]

FIG. 1 is a schematic sectional view showing a state in which oil pockets are formed in the sliding friction material according to the present invention, and FIGS. 2 and 3 are graphs showing the results of a corrosion resistance test and a friction test, respectively.

Claims (1)

[Claims] 1. 10 to 35% by weight on heat-resistant reinforced plastic
A sliding friction material obtained by coating a mixture of an adhesive resin, 5 to 35% aromatic polyester resin, and the balance consisting of tetrafluoroethylene resin, drying and baking the mixture. 2. The sliding friction material according to claim 1, wherein the heat-resistant reinforced plastic is undercoated with a mixture of adhesive resin and tetrafluoroethylene resin. 3 10-35% by weight on heat-resistant reinforced plastic
adhesive resin, 5-35% aromatic polyester resin,
A sliding friction material coated with a mixture consisting of 1 to 15% of one or more solid lubricants and the balance consisting of a tetrafluoroethylene resin, dried and fired. 4. The sliding friction material according to claim 3, wherein the heat-resistant reinforced plastic is undercoated with a mixture of adhesive resin and tetrafluoroethylene resin.