JPH0745675B2 - Polytetrafluoroethylene resin-based sliding material - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial field of application] The present invention relates to a tetrafluoroethylene resin-based base material suitable for sliding members of automobiles, electric machines, OA equipment, industrial machines, machine tools, general industrial machines and the like. Regarding moving materials. Here, the “tetrafluoroethylene resin group” means that the main component is tetrafluoroethylene resin. In addition, hereinafter, tetrafluoroethylene is referred to as PTFE.

[Prior Art] A PTFE sliding material has an extremely small coefficient of friction, but its abrasion resistance is insufficient when used alone. Therefore, in order to improve wear resistance,
Conventionally, an inorganic filler such as glass fiber powder or a resin-based organic filler has been added. Further, since the friction coefficient increases when these wear resistance improving fillers are added, solid lubricants such as soft metal, graphite and MoS ₂ have been added in order to reduce the friction coefficient.

[Problems to be Solved by the Invention] In the conventional PTFE sliding material to which such an inorganic filler such as glass fiber powder or a solid lubricant is added, the abrasion resistance of the sliding material itself is not sufficiently satisfactory. Even if the wear resistance is sufficient, the soft shaft of the mating material, especially the soft shaft such as steam, aluminum, SUS, etc., which has not been subjected to quenching treatment, should be softened by the abrasion powder of the sliding material. It has the drawback of wear. Conventionally, there are additives that do not wear the soft shaft, but there are problems in toxicity, cost, and handling. Further, there is a problem of "squealing", which is a sliding sound generated by the behavior of the abrasion powder during use. It is an object of the present invention to solve the above problems.

[Means for Solving the Problem] First, in a PTFE sliding material, in order to solve the problems relating to wear resistance and wear of the mating shaft, a PTFE resin containing glass fiber powder as a filler is added to an iron oxide of 4 to 6 μm 0.5 to The details of adding 10% by weight will be described below. As the raw material used in the present invention, the molding powder for compression molding sold by general PTFE resin manufacturers can be used as the PTFE resin. As the glass fiber powder, E grade glass fiber powder, which is generally added to PTFE resin or the like, can be used. The iron oxide powder added here is very effective in increasing the wear resistance of the sliding material. Furthermore C
Wear resistance can be increased to the same level as iron oxide powder by using oxide-based fillers such as d, Pb, Sb, etc. Then use should be avoided.

Furthermore, by selecting the particle size and particle shape of the iron oxide powder, it is possible to simultaneously prevent the wear resistance of the sliding agent and the wear of the mating material, especially the soft shaft, due to the effect of the wear powder. Iron oxide powder,
Furthermore, there is no worry of toxicity. Therefore, it was found that the iron oxide powder becomes a filler having very good characteristics and can solve the problems of toxicity, wear resistance, and wear of the mating material. Furthermore, when selecting iron oxide powder of this particle size and particle shape, for example, FeO, Fe
_Since various things such as ₂ O ₃ are generally available on the market, there is no problem in obtaining them for economical production activities.

Main problems can be solved by the method described above. However, even with the sliding material of the present invention, this "squeaking" may become a problem at the time of use because abnormal noise is generated during sliding depending on the operating conditions. In order to prevent this, a special phenol resin powder was found among many substances as an effective filler, and it was found that the addition of this powder can solve the problem of abnormal noise generation. This special phenol resin powder is also commercially available,
It is easy to obtain and there is no problem with toxicity.

The special phenolic resin is a spherical or granular phenolic resin carbonized and fired.

The sliding material having the above additives can be manufactured by a conventional molding method such as compression molding-firing and ram extrusion method without any special change.

[Operation] The reason for limiting each component composition of the sliding material of the present invention as described in the claims (the reason for determining the upper limit and the lower limit) and its effect will be described.

(1) Regarding the amount of iron oxide powder added is 0.5 to 10% by weight.

If the PTFE resin-based sliding material contains iron oxide powder in this proportion,
It is effective in improving the wear resistance of the sliding material itself. If the iron oxide powder is less than 0.5% by weight, the effect does not occur. If the iron oxide powder content exceeds 10% by weight, the mechanical strength of the sliding material is significantly reduced.

(2) Add an amount of iron oxide powder having an average particle size of 4 to 6 μm to 0.
About 5 to 10% by weight.

When the PTFE resin-based sliding material contains iron oxide powder having this particle size and content, it has an effect on the wear of the mating shaft, especially on the soft shaft, and also on the wear resistance of the sliding material itself. If the iron oxide powder of this particle size is less than 0.5% by weight, no effect is produced on wear resistance. If it exceeds 10% by weight, the mechanical strength of the sliding material is significantly reduced.

(3) Regarding addition of 5 to 20% by weight of special phenol resin powder to the sliding member having the composition of (1).

PTFE resin-based sliding material When this amount of special phenol resin powder is included, it prevents the generation of abnormal noise called "squeaking" during sliding,
Effective in reducing the friction coefficient. Special phenolic resin powder 5
If it is less than 10% by weight, no abnormal noise is prevented and the friction coefficient is not lowered, and if it exceeds 20% by weight, the mechanical strength of the sliding material is significantly reduced.

(4) Regarding adding 5 to 20% by weight of special phenol resin powder to the sliding material containing the composition of (2).

In addition to the effect of the iron oxide powder having a uniform particle size as described above, it is effective in preventing abnormal noise and reducing the friction coefficient. If the special phenol resin powder is less than 5% by weight, no abnormal noise is prevented and the friction coefficient is not reduced, and if the special phenol resin powder exceeds 20% by weight, the mechanical strength of the sliding material is significantly reduced.

[Examples] Specific examples will be described below. PTFE resin 1 (Mitsui DuPont Fluorochemical; Teflon 7J) and glass fiber powder 2 (Nippon Glass Fiber; REV-1, fiber diameter 13μ)
m, average fiber length 35 μm), iron oxide powder 3 (Morishita Benji; M
R-660E, average particle size 0.36 μm), particle size adjustment specific iron oxide powder 3 (manufactured by Dainichiseika; TFD-0831, average particle size 4 to 6 μm),
Special phenolic resin powder 4 (Kanebo; registered trademark Bell Pearl C-2000, average particle size 15-20 μm), cadmium sulfide +
Cadmium selenide powder (Dainichi Seika; Pyro Fine Color Red 3B # 8000), PbO powder (Nippon Kagaku Kogyo;
Lisage No. 1 yellow mouth, average particle size 5 μm), Sb ₂ O ₃ powder (manufactured by Nippon Mining Co., Ltd .; antimony trisulfide P ₄ 99% -200mesh), lead chromate powder (manufactured by Japan Inorganic Chemical Industry Co., Ltd., Cinard Red 90)
05), ceramic pigment (Ikegaki Chemical; No.100 Ping 50Sn, 10C
r, 20Si, 20CaCo ₃ average particle diameter 3 μm) Further, barium sulfate powder (manufactured by Kishida Chemical Co., Ltd .; chemical) was used as a raw material and weighed in a weight mixing ratio shown in Table 1, and mixed with stirring with a Henschel mixer manufactured by Mitsui Miike. Put the mixed powders in the mold and after compression molding 370
The molded product was formed by heating and firing at 3 ° C. for 3 hours. From the molded body, tensile and elongation measurement test pieces and friction and wear test cylindrical bearings were prepared by cutting. The test conditions were non-lubrication, speed: 0.1 m / sec, load: 15 kg / cm ² , mating shaft: S55C, no quenching, surface roughness R _max = 1.5 μm, and a friction coefficient The amount of bearing wear and the degree of damage to the mating shaft were measured for abnormal noise. The results are shown in Table 1.

In Comparative Examples 11 to 16 and Examples 1 to 3 shown in Table 1, the addition amount of the glass fiber powder was set to 5 to 20% by weight and the iron oxide powder was set to 0.5 to 10% by weight, and the bearing wear amount was tested and compared. . The composition and bearing tests were conducted mainly on the glass fiber added in an amount of 20% by weight, which was used as a criterion for determining other compositions. In Examples 1 to 3 and Comparative Examples 6 to 10, the effect of the filler added next to the glass fiber powder is found. First, it can be seen that the addition of the specific iron oxide powder improves the wear resistance of the bearing. Also, Cd (S, S
e) Regarding powder, PbO powder, and lead chromate powder, the friction coefficient, bearing friction, and extent of damage to the mating shaft are satisfactory as sliding materials. Further, the Cd (S, Se) powder and the lead chromate powder are satisfactory because no abnormal noise is generated. But these
Cd (S, Se), PbO, chromium zinc have problems with toxicity. Therefore, in terms of actual production activities, equipment for preventing pollution is expensive in handling, and when it is commercialized, it cannot be used for applications where importance is given to toxicity considerations such as food equipment, and the applications are limited. In this respect, the addition of the specific iron oxide powder makes it possible to sufficiently improve the wear resistance of the bearing and to produce a high-quality bearing. Further, in Examples 1 to 3, the effect of the specific iron oxide powder in which the average particle diameter of the iron oxide powder is 4 to 6 μm becomes clear. It can be seen that by adjusting the particle diameters to 4 to 6 μm, the surface of the mating material is rapidly polished and the generation of wear particles is reduced, resulting in prevention of abrasive wear. After all, it is clear that if the particle size is specified by using a safe iron oxide powder, the same performance as the Cd (S, Se) powder, PbO powder, and lead chromate powder, which are problematic due to toxicity described above, can be obtained. Became. Further, from Examples 4 and 5 and Comparative Examples 11 to 14, the addition of the special phenol resin powder is effective in generating abnormal noise called "squeaking" during sliding and also in reducing the friction coefficient. Comparing the effects of addition of the special phenol resin powder (Examples 4 and 5), the BaSO ₄ powder (Comparative Example 11) and the CaF ₂ powder (Comparative Example 12), it is possible to prevent abnormal noise and reduce the friction coefficient. It is clear that the powder addition has a great effect.

Furthermore, looking at Examples 4 and 5 in which the iron oxide powder was made to have an average particle size of 4 to 6 μm, the iron oxide powder particle size was specified in addition to the effect of adding the special phenol resin powder. As in Examples 1 to 3, it can be seen that a great effect is exhibited against the wear of the mating shaft.

[Advantages of the Invention] (1) Effect of Filling Sliding Material with Iron Oxide Powder By adding iron oxide powder, which is a non-toxic filler in the wear resistance of the bearing using this sliding material, With respect to wear, the performance is significantly improved as compared with the case where only glass fiber powder is added.

(2) Effect of specifying the particle size of iron oxide powder By preventing the generation of wear particles in the sliding state and damaging the mating shaft (soft shaft) at the time of occurrence of wear, by specifying the particle diameter and shape, it is possible to greatly Can be obtained.

Even with toxic additives such as Cd and Se, it was found that they could be used if it was only intended to obtain the effects of the above-mentioned items, but in the case of non-toxic iron oxide powder, particles of The effect can be obtained by specifying the diameter and shape.

By filling the non-toxic specific iron oxide powder described in the above section, it can be used as a sliding material in industrial fields such as food processing equipment, which could not be used due to toxicity, and the field of use can be expanded.

(3) Effect of filling with special phenol resin powder The abrasion powder generated during sliding and the abnormal noise generated between the shafts can be completely prevented by adding the special phenol resin powder.

When the special phenol resin powder has a spherical shape or a granular shape, when it is generated as abrasion powder, it is effective in reducing the friction coefficient.

[Brief description of drawings]

The drawings show examples of the present invention. FIG. 1 is a photograph showing a grain structure in a typical enlarged cross-sectional structure of a sliding material by a metallographic microscope, and FIG. 2 is a grain structure in an electron microscopic structure of iron oxide powder. The photograph shown in FIG. 3 is a photograph showing the particle structure in the electron microscope structure in which the particle size of the iron oxide powder is specified, and FIG. 4 is the photograph showing the particle structure in the electron microscope structure of the special phenol resin powder.

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Claims (2)

[Claims] 1. A tetrafluoroethylene resin containing 10 to 30% by weight of glass fiber powder as a filler and having an average particle size of 4 to 6
A tetrafluoroethylene resin-based sliding material with 0.5 to 10% of iron oxide powder of μm added. 2. A tetrafluoroethylene resin containing 10 to 30% by weight of glass fiber powder as a filler and having an average particle size of 4 to 6
A tetrafluoroethylene resin-based sliding material containing 0.5 to 10% of iron oxide powder of μm, and 5 to 20% of special phenol resin powder obtained by firing spherical or granular phenol resin powder.