JPH04114094A - Sliding material of tetrafluoroethylene resin base - Google Patents

Abstract

PURPOSE:To obtain the title atoxic material having excellent wear resistance and reduced coefficient of friction by blending tetrafluoroethylene resin mixed with glass fiber powder as a filler with iron oxide powder. CONSTITUTION:(A) Tetrafluoroethylene resin mixed with 10-30wt.% glass fiber powder as a filler is blended with (B) 0.1-10wt.% iron oxide powder having 1-10mum (preferably 4-6mum) average particle diameter and optionally (C) 0.1-20wt.% spherical or granular phenol resin powder to give the objective material.

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention provides a polytetrafluoroethylene resin base material suitable for sliding members of automobiles, electric machines, OA equipment, industrial machines, machine tools, general industrial machines, etc. Regarding dynamic materials. Here, [tetrafluoroethylene resin 5] means that the main component is tetrafluoroethylene resin. In addition, below, when is tetrafluoroethylene and PTFE?

[Prior Art J PTFE sliding material has a very small coefficient of friction, but its wear resistance is insufficient when used alone. Therefore, in order to improve wear resistance, inorganic fillers such as glass fiber powder and resin-based organic fillers have conventionally been added. In addition, adding these wear resistance improving fillers increases the friction coefficient, so in order to lower the friction coefficient, soft metals, graphite, M
A solid lubricant such as O82 was added.

[Problem to be Solved by the Invention 1] In such conventional PTFE sliding materials to which an inorganic filler such as glass fiber powder or a solid lubricant is added, the wear resistance of the sliding material itself is not sufficiently satisfactory. In addition, even if wear resistance is sufficient, soft shafts that are mating materials, especially soft shafts made of unhardened steel, aluminum, SUS, etc., may be damaged by abrasion powder from the sliding material. It has the disadvantage of causing wear. Conventionally, additives that do not cause wear on soft shafts exist, but they have problems with toxicity, cost, and handling. Furthermore, there is a problem of "F-squeak" which is a sliding sound generated by the behavior of abrasion powder during use. It is an object of the present invention to solve the above problems.

[Means to Solve the Problem] First, in order to solve the problems related to wear resistance and mating shaft wear in PTFE sliding materials, 0.1 to 10 weight of iron oxide was added to the PTFE resin containing glass fiber powder as a filler. % addition will be explained in detail below. As the raw material for the PTFE resin used in this invention, molding powder for compression molding sold by general PTFE resin manufacturers can be used.

Further, as the glass fiber powder, E grade glass fiber powder, which is generally added to PTFE a-fat or the like, can be used. The iron oxide powder added here is very effective in increasing the wear resistance of sliding materials. Furthermore, Cd,
By using oxide fillers such as Pb and Sb, wear resistance can be improved to the same level as iron oxide powder, but
Even if these are effective, there are problems with toxicity, and their use should be avoided in consideration of environmental issues.

Furthermore, by selecting the particle size and shape of the iron oxide powder, it is possible to simultaneously improve the wear resistance of the sliding agent and prevent wear due to the influence of wear particles on the mating material, especially the soft shaft. Iron oxide powder is
Furthermore, there is no need to worry about toxicity.

Therefore, it was found that iron oxide powder becomes a filler with very good properties and can solve the problems of toxicity, wear resistance, and wear of the mating material. Furthermore, when selecting iron oxide powder with this particle size and shape, for example, Fed.

Since various products such as Fe2O3 are generally commercially available, there is no problem in obtaining them for economical production activities.

The main problems can be solved by the methods described above. However, even with the sliding material of the present invention, abnormal noise is generated during sliding depending on the conditions of use, and this "squeak" may become a problem during use. In order to prevent this, a special phenolic resin powder was found among many substances as an effective filler, and it was found that the addition of this powder could solve the problem of noise generation. This special phenolic resin powder is also commercially available.
It is easy to use manually and there are no problems with toxicity.

Note that the special phenol resin refers to a spherical or granular phenol resin that is carbonized and fired.

Sliding materials containing the above additives can be manufactured by conventional molding methods such as compression molding→sintering, ram extrusion, etc. without any special changes.

[Function] The reasons for limiting the composition of each component of the sliding material of the present invention as described in the claims (reasons for determining upper and lower limits) and the effects thereof will be described.

(1) Regarding the point that the amount of iron oxide powder added is 0.1 to 10% by weight.

When 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 amount of iron oxide powder is less than 0.1% by weight, this effect will not occur. Moreover, if the iron oxide powder exceeds 10% by weight, the mechanical strength of the sliding material will be significantly reduced.

(2) Regarding the point that the amount of iron oxide powder with an average particle size of 1 to 10 μm is 0.1 to 10% by weight.

When the PTFE resin-based sliding material contains iron oxide powder of this particle size and content, it is effective against the wear of the mating shaft, especially the soft shaft, and is also effective in improving the wear resistance of the sliding material itself. If the iron oxide powder of this particle size is less than 0.1% by weight, no effect on wear resistance will be produced. Moreover, if it exceeds 10% by weight, the mechanical strength of the sliding material will be significantly reduced.

(3) Regarding the addition of 0.1 to 20% by weight of special phenolic resin powder to the sliding member having the composition of item (1).

PTFE resin-based sliding material When this amount of special phenolic resin powder is added, it is effective in preventing the generation of abnormal noise called "squeak" during sliding and in lowering the coefficient of friction. If the special phenol resin powder is less than 0.1% by weight, it will not be effective in preventing noise generation or reducing the coefficient of friction, and if it exceeds 20% by weight, the mechanical strength of the sliding material will be significantly reduced.

(4) Regarding the addition of 0.1 to 20% by weight of special phenolic resin powder to the sliding material containing the composition in item (2).

In addition to the aforementioned effects of iron oxide powder with uniform particle size, it is also effective in preventing noise generation and lowering the coefficient of friction. If the special phenol resin powder is less than 0.1% by weight, it will not be effective in preventing noise generation or lowering the coefficient of friction.
If it exceeds 0% by weight, the mechanical strength of the sliding material will be significantly reduced.

[Example] Hereinafter, the present invention will be specifically explained by giving examples. PTFE resin 1
(manufactured by Mitsui DuPont Fluorochemical; Teflon 7J) and glass fiber powder 2 (manufactured by Nippon Glass Fiber; REV-1,
Fiber diameter 13 μm, average fiber length 35 μm), iron oxide powder 3 (manufactured by Morishita Bengara; MR-660E, average particle size 0.36)
μm), particle size adjusted specific iron oxide powder 3 (manufactured by Dainichiseika;
TFD-0831, average particle size 4-6 μm), special phenolic resin powder 4 (manufactured by Kanebo; registered trademark Bell Pearl C-2)
000, average particle size 15-20 μm), cadmium sulfide +
5
b203 powder (made by Nippon Seiko; antimony trisulfide P499
%-200mesh), lead chromate powder (Japan Inorganic Chemical Industry Co., Ltd.; Cynartread 9005), ceramic pigment (Ikegaki Chemical Co., Ltd.; No. 100 Ping 50Sn, 1
0Cr, 20Si, 20CaCo3 average particle size 3 μm
) Further, barium sulfate powder (manufactured by Kishida Chemical Co., Ltd. for chemical use) was weighed as a raw material at the weight blending ratio shown in Table 1, and mixed by stirring using a Henschel mixer manufactured by Mitsui Miike. The mixed powder was put into a mold, and after compression molding, it was heated and fired at 370° C. for 13 hours to form a molded body. A test piece for tensile and elongation measurements and a cylindrical bearing for friction and wear tests were fabricated from the molded body by cutting. Test conditions: no lubrication, speed: 0.1 m/
see, load; 15 kg/cm2, mating shaft;
555C1 No hardening, surface roughness Rmax=1.5μm
A test was conducted using a cylindrical bearing testing machine to measure the friction coefficient, amount of bearing wear, degree of damage to the mating shaft, and the presence or absence of abnormal noise. The results are shown in Table 1.

Comparative Examples 15.16.17 and Examples 2.3 shown in Table 1.
4, the amount of glass fiber powder added was 10 to 3.
The amount of bearing wear was tested and compared within the range of 0% by weight. Composition and bearing tests were further conducted mainly on those with a small amount of bearing wear but with an added amount of glass fiber, that is, 20% by weight, and were used as the basis for determining other compositions. In Examples 1 to 5 and Comparative Examples 18 to 22, the effect of the filler added after the glass fiber powder is revealed. First, it can be seen that the addition of iron oxide powder improves the wear resistance of the bearing. Furthermore, Cd (S, Se) powder, PbO powder, and lead chromate powder are satisfactory as sliding materials in terms of friction coefficient, amount of bearing wear, and degree of damage to the mating shaft. Furthermore, Cd (S, Se) powder and lead chromate powder do not generate any abnormal noise and are satisfactory. However, these Cd (
S, Se), PbO, and lead chromate have problems with toxicity. Therefore, in actual production activities, equipment to prevent contamination during handling is expensive, and when it is commercialized, it cannot be used in applications where consideration of toxicity is important, such as food equipment, and its usage is limited.

In this respect, by adding iron oxide powder, the wear resistance of the bearing can be sufficiently improved and a high quality bearing can be produced. Furthermore, in Examples 6 to 8, the effect of the specific iron oxide powder in which the average particle size of the iron oxide powder was adjusted to 4 to 6 μm becomes clear. It can be seen that by adjusting the particle size to 4 to 6 μm, the surface of the mating material is quickly polished, the generation of abrasion powder is reduced, and as a result, abrasive wear is prevented. In the end, Cd (S, S), which has the problem of toxicity mentioned earlier,
e) It has become clear that the same performance as powder, PBO powder, and lead chromate powder can be obtained with safe iron oxide powder by specifying its particle size. Furthermore, from Examples 9 to 11 and Comparative Examples 23 and 24, the addition of special phenol resin powder was found to be effective in reducing the generation of abnormal noise called "squeal" during sliding, and was also found to be effective in reducing the coefficient of friction. Special phenolic resin powder (Example 10.11.13.14) and B
a5O powder (Comparative Example 23), CaF2 powder (Comparative Example 24)
), it is clear that the addition of special phenol resin powder has a great effect on preventing noise generation and lowering the coefficient of friction.

Furthermore, looking at Examples 12 to 14 in which the average particle size of the iron oxide powder was adjusted to 4 to 6 μm, in addition to the effect of adding special phenolic resin powder as shown in Examples 9 to 11, iron oxide Example 6 by specifying powder filling
It can be seen that, similar to cases 8 to 8, it has a great effect on the wear of the mating shaft.

[Effect of the invention 1 (1) Effect of filling the sliding material with iron oxide powder ■ The wear resistance of a bearing using this sliding material is improved by adding iron oxide powder, which is a non-toxic filler. Regarding bearing wear, performance is greatly improved compared to those that only contain glass fiber powder.

(2) Effect of specifying the particle size of iron oxide powder■ By specifying the particle size and shape, it is possible to prevent the generation of wear particles during sliding conditions and damage to the mating shaft (soft shaft) when wear occurs. Great effects can be obtained.

■ Even with toxic additives such as Cd and Se, it was found that if the intention was to obtain the effect described in item 0 above, it was sufficient to use them, but in non-toxic iron oxide powder, This effect can be obtained by specifying the diameter and shape of the particles.

■ Filling with non-toxic iron oxide powder as explained in item 0 above allows it to be used as a sliding material in industrial fields where it could not be used due to toxicity, such as food equipment, and the range of applications can be expanded.

(3) Effects of filling with special phenolic resin powder ■ The addition of special phenolic resin powder can completely prevent abrasion powder generated during sliding and abnormal noise generated between the shafts.

- Since the special phenol resin powder is spherical or granular in shape, it is effective in reducing the coefficient of friction when it is generated as wear powder.

[Brief explanation of drawings]

Claims (4)

[Claims] (1) Add 0.1% iron oxide powder to tetrafluoroethylene resin filled with 10-30% glass fiber powder by weight.
Tetrafluoroethylene resin-based sliding material with ~10% addition. (2) The tetrafluoroethylene resin-based sliding material according to claim (1), wherein the iron oxide powder has an average particle size of 1 to 10 μm. (3) Add 0.1% iron oxide powder to tetrafluoroethylene resin filled with 10-30% glass fiber powder by weight.
Special phenolic resin powder 0.1 to 20% with ~10% added and further calcined spherical or granular phenolic resin powder
Added tetrafluoroethylene resin-based sliding material. (4) The tetrafluoroethylene resin-based sliding material according to claim (3), wherein the iron oxide powder has an average particle size of 1 to 10 μm.