JP2002285183A - Solid lubricant - Google Patents

Abstract

PROBLEM TO BE SOLVED: To solve problems that when a solid lubricant is used by dispersing it n a liquid lubricant a problem of environmental pollution is occurred by splashing the liquid lubricant and also when the solid lubricant is used as a solid state by dispersing it in a polymeric material, the durability becomes short and generating the ablated dust. SOLUTION: This perfect solid lubricant obtained by dispersing the liquid lubricant impregnated filler prepared by impregnating the liquid lubricant in micro holes presenting in the filler such as the solid lubricant, is used as a boundary lubrication to solve the problems of the environmental pollution and durability, and also improve its mechanical strength.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a solid lubricant used for sliding parts such as mechanical parts.

[0002]

2. Description of the Related Art A friction coefficient can be reduced by using a liquid lubricant in a sliding portion of a mechanical part. However, in many cases, an excessive amount of a liquid lubricant is used, and the friction coefficient, which is an initial purpose, is reduced. Although it can be done, the excess amount causes environmental pollution.

[0003] It is possible to reduce the amount of wear by lowering the coefficient of friction by merely adding a small amount of liquid lubricant to the sliding portion of a machine component, but it is not possible to supply a minimum amount of liquid lubricant. Very difficult.

Providing the minimum required amount of liquid lubricant is
This is possible if such a supply mechanism is newly provided, but the periphery of the mechanical parts becomes complicated, and the increase in size leads to an increase in cost.

In recent years, in order to prevent environmental pollution, solid lubricants have been used instead of liquid lubricants for sliding parts of mechanical parts and the like. Examples of solid lubricants include graphite, molybdenum disulfide, zinc disulfide, and the like. An inorganic material such as copper disulfide or an organic material represented by polytetrafluoroethylene (PTFE) or fluorinated graphite is used.

The inorganic solid lubricant described above is characterized by its molecular structure, having a structure in which flat plate crystals are arranged in a layered manner, and the layered portion is slid by pressurization during sliding to exhibit a lubricating effect. It is said that. On the other hand, an organic solid lubricant is mainly characterized by a compound having a fluorine atom bonded thereto, and exhibits a lubricating action by a small surface energy caused by the fluorine atom.

In order to prevent environmental pollution due to the use of a liquid lubricant, a solid lubricant such as graphite, molybdenum disulfide or PTFE is dispersed in a polymer material to reduce the friction coefficient in the absence of a liquid lubricant. Although it is possible to prevent environmental pollution caused by liquid lubricants, durability can be achieved by the generation of abrasion powder, especially the surface roughness of the sliding parts of machine parts greatly affects the generation of abrasion powder. The problem of worsening occurs.

In some cases, the above-mentioned solid lubricant is dispersed in a liquid lubricant and used. However, this is not a complete solid lubricant because the liquid lubricant is used, and the liquid lubricant is scattered in the air. The problem of polluting the environment occurs.

[0009]

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and an object of the present invention is to reduce the amount of abrasion powder generated and to reduce the scattering of a liquid lubricant into the air. The object is to provide a solid lubricant which can prevent pollution to the environment by preventing it.

[0010]

In order to achieve the above object, the solid lubricant of the present invention employs the following constitution. That is, the solid lubricant of the present invention is a solid lubricant in which a filler is dispersed in a polymer material, wherein the filler is impregnated with a lubricant composition.

In the above, fillers such as solid lubricants such as graphite and molybdenum disulfide used by being dispersed in a polymer material have micropores and must be impregnated with a liquid lubricant. Is possible.

For example, a liquid lubricant can be impregnated into the micropores of these fillers by a method of adding a liquid lubricant, that is, a vacuum injection method, by placing a filler such as a solid lubricant under vacuum.

[0013] By dispersing these fillers in a polymer material and applying them to sliding parts of mechanical parts, sufficient friction can be obtained even when the mating material at the time of sliding is a material having high hardness such as metal or ceramics. At the same time as the coefficient is reduced, the generation of wear powder can be suppressed.

A friction mechanism when this filler is used for a sliding portion of a machine component. When a part of the surface of the filler dispersed in a polymer material is exposed to the sliding portion, friction is caused at the same time as slight friction. The lubricant composition, that is, a mechanism in which the liquid lubricant is discharged from the micropores to form a “boundary lubrication state”, exhibits a reduction in the coefficient of friction.

[0015] The solid lubricant itself has a lubricating function and further serves not only as a mere holding material of the liquid lubricant but also as a kind of a filler. The function to improve is also expressed.

Although the description has been given of the filler impregnated with the lubricant composition, the filler impregnated with the lubricant composition may be a filler having no lubricating function, for example, silicon oxide. Based on the required characteristics of the sliding portion, the filler can be used alone or mixed with a solid lubricant and a filler component and dispersed in a polymer material.

[0017]

Next, embodiments of the present invention will be described in detail.

As the polymer material, either a thermosetting resin or a thermoplastic resin can be used. In the case of the thermosetting resin, a filler impregnated with a liquid lubricant as a lubricant composition at room temperature is used. After dispersing, by using heat curing, it is possible to form a film with a fixed thickness on various substrates with good adhesion.

In the case of a thermoplastic resin, after the filler impregnated with the lubricant composition is dispersed in a molten state,
Although it is not possible to form a film on various substrates with good adhesion, it is characterized in that it can be formed into various shapes alone.

The average particle size of a filler such as a solid lubricant dispersed in a polymer material cannot be determined uniquely because it depends on the target film thickness. Easy to do.

Although the amount of the lubricant composition impregnated into the micropores of the filler such as a solid lubricant is small, the filler such as a solid lubricant impregnated with the lubricant composition is converted into a polymer material. The amount to be dispersed is 10 to 40% by weight, and the amount to be dispersed can be properly used according to the purpose.

When the solid lubricant is PTFE, there are almost no micropores, so that the lubricant composition cannot be impregnated. However, in combination with a filler impregnated with the lubricant composition, a polymer material is used. The friction coefficient can be reduced by the mechanism for forming the "boundary lubrication state".

[0023]

EXAMPLES Hereinafter, a test piece was prepared by dispersing a filler impregnated with a lubricant composition in an epoxy resin, and subjected to a sliding test using a tribogear 14DR (Shinto Kagaku Co., Ltd.) to obtain an initial static friction. The coefficient and the dynamic friction coefficient were determined and the characteristics were evaluated.
After performing reciprocal sliding of 50,000 times in mm, the static friction coefficient and the dynamic friction coefficient were determined.

The coefficient of static friction represents the characteristics at the start of sliding, and the coefficient of kinetic friction represents the frictional characteristics at the time of sliding. For an automatic assembly machine, it is desired that both are low. In addition, the initial characteristics and the coefficient of friction after 50,000 times of sliding are measured, which reflect the state of wear of the sliding part,
The smaller the change in the coefficient of friction between the two is, the better, and a solid lubricant with as little change as possible is desired.

The bending strength of the above test piece was JIS K72.
03, and the mechanical strength was compared. Shimadzu EZ-TEST was used as a measuring device.

Example 1 5 gr of molybdenum disulfide having an average particle size of 0.5 μm was stored under vacuum (about 0.01 Torr), and then 50 mL of a liquid lubricant spindle oil was injected under vacuum to impregnate the molybdenum disulfide. I let it. The molybdenum disulfide impregnated in vacuum was taken out, and the surface was washed with petroleum ether to remove spindle oil adhering to the surface, and dried at room temperature.

After dispersing the spindle oil-impregnated molybdenum disulfide in a bisphenol A-based epoxy resin as a main component such that the concentration becomes 10% by weight, a predetermined amount of a modified amine-based curing agent is added and mixed well. A predetermined amount of the mixed suspension was taken out and placed on a test piece base material (10 mm × 10 mm) made of S45C.
mm x 3 mm) with a thickness of about 2 mm
It was cured by heating for 0 minutes.

The flexural strength was 3 kgf / mm ² .

A sliding test was performed using the test piece and a flat indenter made of S45C as a mating material. The sliding conditions at that time were as follows: load 9.8 N, speed 6 m / min, moving distance 20
The results of measurement of the initial state and the coefficient of friction after 50,000 slides are shown below.

Example 2 Using a graphite having an average particle size of 0.5 μm, in the same manner as in Example 1, about 2 mm of epoxy resin containing 10% by weight of graphite containing spindle oil on a test piece base material. Apply at a thickness of 60 at 80 ° C
Heat cured for minutes. The initial state and the friction coefficient and the bending strength after 50,000 times of sliding obtained by the same method as in Example 1 are shown below.

Example 3 The concentration of the spindle oil-impregnated molybdenum disulfide obtained in Example 1 was 5% by weight and PT
After dispersing two types of solid lubricants in a bisphenol A-based epoxy resin as a main component, a solid lubricant component mixed so that the concentration of FE becomes 5% by weight, a predetermined amount of a modified amine-based curing agent may be added. Mix. A predetermined amount of the mixed suspension was taken out and placed on a test piece base material of S45C (10 mm × 1
(0 mm × 3 mm) with a thickness of about 2 mm, and cured by heating at 80 ° C. for 60 minutes.

A sliding test was performed using the test piece and a flat indenter made of S45C as a mating material. The sliding conditions were as follows: load 9.8 N, speed 6 m / min, moving distance 20
The measurement results of the initial state and the friction coefficient and the bending strength after 50,000 sliding operations are shown below.

Example 4 5% by weight of graphite containing spindle oil and PTF on a test piece base material in the same manner as in Example 1 using graphite having an average particle size of 0.5 μm.
An epoxy resin containing a solid lubricant component mixed with E5% by weight was applied to a thickness of about 2 mm, and cured by heating at 80 ° C. for 60 minutes. The initial state and the friction coefficient and the bending strength after 50,000 times of sliding obtained by the same method as in Example 1 are shown below.

When a filler such as an inorganic solid lubricant impregnated with a liquid lubricant is dispersed in a polymer material as described above, these fillers and PTFE as an organic solid lubricant are also used. It was clarified that the same "boundary lubrication function" was exhibited and the mechanical strength was also improved when mixed.

(Comparative Example 1) After dispersing in a bisphenol A-based epoxy resin as a main component such that the concentration of molybdenum disulfide having an average particle size of 0.5 μm becomes 10% by weight, a modified amine-based curing agent was added in a predetermined amount. In addition, mix well. A predetermined amount of this mixed suspension was taken out, applied on a test piece base material (10 mm × 10 mm × 3 mm) made of S45C at a thickness of about 2 mm, and cured by heating at 80 ° C. for 60 minutes.

A sliding test was performed using the test piece and a flat indenter made of S45C as a mating material. The sliding conditions at that time were as follows: load 9.8 N, speed 6 m / min, moving distance 20
The measurement results of the initial state and the friction coefficient and the bending strength after 50,000 sliding operations are shown below.

(Comparative Example 2) A test piece was prepared in the same manner as in Comparative Example 1 so that the concentration of graphite having an average particle size of 2.5 μm was 10% by weight, and sliding using S45C as a mating material was performed. The test is performed, and the initial state and the measurement results of the coefficient of friction and the bending strength after 50,000 slides are shown below.

Comparative Example 3 PTF having an average particle size of 0.5 μm
A test piece was prepared in the same manner as in Comparative Example 1 so that the concentration of E became 10% by weight, and a sliding test was performed using S45C as a mating material, and the initial state and the friction coefficient after 50,000 sliding operations were performed. And the measurement results of the bending strength are shown below.

In the above comparative example, the mechanical strength is improved because the filler component is dispersed in the polymer material. However, since the liquid lubricant is not impregnated, no "boundary lubrication state" is formed, so that the static friction is reduced. The measured values of the coefficient and the coefficient of kinetic friction increase, and the sliding characteristics are not good.

[0040]

According to the present invention, a solid lubricant obtained by dispersing a filler impregnated with a lubricant composition comprising a lubricating oil in a polymer material has excellent sliding properties, particularly excellent "boundary lubrication properties". By reducing the friction coefficient, the use of liquid does not use the liquid, so there is less environmental pollution and the friction coefficient is lower than solid lubricant not impregnated with liquid lubricant. This has the effect that the mechanical strength can be improved at the same time as the reduction.

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Claims (4)

[Claims] 1. A solid lubricant in which a filler is dispersed in a polymer material, wherein the filler is impregnated with a lubricant composition. 2. The solid lubricant according to claim 1, wherein the polymer material is one of a thermoplastic resin and a thermosetting resin. 3. The solid lubricant according to claim 1, wherein the lubricant composition is one of a lubricating oil and a grease. 4. The solid lubricant according to claim 1, wherein the filler has fine holes.