JPH04314788A - Solid lubricating film and its production - Google Patents

Abstract

PURPOSE:To obtain a solid lubricating film which has a low frictional coefficient in a wide temperature range. CONSTITUTION:A solid lubricating film is produced by applying a mixture comprising sericite and/or boron nitride and a coating binder and water to the surface of an object to form a film thereon and solidifying the film by heating. This film is formed on the sliding surface of a machine element which slides.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention This invention relates to a solid lubricant coating used to reduce the coefficient of friction of sliding parts of mechanical elements and the like, and a method for producing the same.

0002

2. Description of the Related Art In recent years, the demand for lubrication of sliding mechanical elements in the atmosphere from about room temperature to high temperatures has increased dramatically. In addition, in the field of plastic processing, energy savings and
Lubricants are becoming increasingly important in order to reduce tool seizure and wear, and improve the surface quality of products. Among these, it is preferable to use a solid lubricant that can withstand temperatures of several hundred degrees Celsius or higher, which cannot be achieved with conventional lubricating oils. Typical solid lubricants include graphite, molybdenum disulfide (MoS2), and tungsten disulfide (WS).
2) There is polytetrafluoroethylene (PTFE).

0003

[Problems to be Solved by the Invention] However, the above-mentioned solid lubricants conventionally used are
There is a problem that it deteriorates due to oxidation and loses its lubricity. Furthermore, all of these solid lubricants except PTFE are black in color and are often disliked because they tend to stain the clothing of the user and cause discomfort. On the other hand, boron nitride (
BN) is a white lubricating powder that exhibits oxidation resistance up to 900°C, but it is difficult to obtain an excellent lubricating film that takes full advantage of its lubricating performance. Furthermore, there is sericite which has a gray color. It does not change in quality up to about 1000°C and exhibits lubricity. It is also difficult to obtain a film that exhibits sufficient lubrication performance.

The present invention was made in view of the above circumstances, and an object thereof is to provide a white lubricating coating that takes advantage of the lubricity and heat resistance of both boron nitride and sericite, and a method for producing the same. That is.

[0005]

[Means for Solving the Problems] Corresponding to this object, the solid lubricant film of the present invention is a solid lubricant film formed on the lubricated surface of an object to be lubricated, and comprises one of sericite, boron nitride, or It is characterized by being made by heating and solidifying a mixture of both and a coating binder. The method for producing a solid lubricating film of the present invention involves applying a stirred mixture of one or both of sericite and boron nitride, a coating binder, and water to the lubricated surface of an object to be lubricated to form a coating film. After that, the coating film is heated and solidified.

[0006]

[Operation] A solid lubricating film is formed to cover the sliding surfaces of mechanical elements that move. Solid lubricant coatings exhibit low coefficients of friction over a wide temperature range. The raw material for the solid lubricant coating of this invention is white or gray, and the solid lubricant coating is also white or gray, so that it does not cause discomfort to the user.

[0007]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The details of this invention will be explained below with reference to the drawings showing one embodiment. In FIG. 1, reference numeral 1 denotes a solid lubricant coating, and the solid lubricant coating 1 is formed on the sliding surfaces of mechanical elements 2 and 3 to reduce the coefficient of friction of the sliding surfaces. The solid lubricant coating 1 is made of boron nitride BN or sericite.
A mixture of one or both of these and a coating binder is heated and solidified.

An example of the composition of Sericite is shown in Table 1 below.

[Table 1]

[0009] The coating method is to use various water glasses (sodium silicate, lithium silicate, potassium silicate, etc.), aqueous silica sol, and other coating binders of 1 to 50W.
Water is added to t% to obtain a mixed stirred product whose viscosity is adjusted to a state where the next powder can be sufficiently stirred. As the aqueous silica sol, for example, commercially available Cataloid-S (trade name, manufactured by Catalysts & Chemicals Co., Ltd.) can be used. The viscosity is determined depending on the application means and application conditions when applying the stirred mixture to the mechanical elements. Add 1 part of boron nitride to this stirred mixture.
~94Wt% or 1~94W of water-dispersed sericite
After spraying or brushing on the desired surface, heat the mixture to a temperature of 30°C to 150°C, preferably every 100°C for at least 30 minutes, preferably for at least 1 hour. Keep heated. Eventually 1
A lubricating film is obtained by heating between 50° C. and 1000° C. for 1 hour or more depending on the usage conditions. or about 100℃~300℃
When spraying onto a part heated to 0.degree. C., a solid lubricant coating 1 can be obtained within a few seconds to an hour.

(Experimental example) The experimental results show the relationship between temperature and friction coefficient when reciprocating friction is performed using a pin-block friction test piece as shown in Figure 2 (in the figure, 5 is a pin, 2 is a block and 6 is a block). shows.

FIGS. 3(a) and 3(b) are both results of examinations of ceramics of the same type in the absence of a solid lubricant. Si3 has relatively little change in friction coefficient due to temperature
With the exception of N4, all of them show a change in friction coefficient depending on temperature, and the overall friction coefficient shows a high value ranging from 0.4 to 1.1 or more.

FIG. 4 shows the test results of various ceramics coated with MoS2 films using epoxy as a binder. All of them exhibit excellent lubricity with a friction coefficient of 0.1 or less up to a temperature of 400°C, but when the temperature exceeds 500°C, the lubricity is extremely lost, and the lubricating film of the test piece once heated to 1000°C is completely lost. It disappears due to oxidation, etc., and does not return to its original low coefficient of friction over the entire temperature range.

On the other hand, an example of the sericite and boron nitride solid lubricating coating according to the present invention is shown in FIG. In this example, 5 g of water was added to 10 g of water-dispersed sericite, 10 g of boron nitride, and 80 g of sodium silicate No. 3, and mixed with stirring.
3 After coating on the N4 test piece, the temperature was increased at a rate of 100°C/hour, and the temperature was increased to 900°C while holding for 1 hour at every 100°C.
These are the results of an investigation of the film heated to . Room temperature ~1
It can be seen that the lubricating effect is exhibited over the entire temperature range of 000°C, the waiting coefficient is in the range of 0.35 to 0.25, and the change in the coefficient of friction due to temperature is extremely small.

[0014]

[Effects of the Invention] As described above, the solid lubricant coating of the present invention has a low coefficient. Moreover, it exhibits excellent lubricity with extremely little change in friction coefficient due to temperature.

[Brief explanation of drawings]

FIG. 1 is an explanatory cross-sectional view showing a solid lubricant coating.

FIG. 2 is a perspective explanatory view showing a pin block friction test piece.

FIG. 3 is a graph showing the relationship between temperature and friction coefficient between ceramics.

FIG. 4 is a graph showing the relationship between temperature and friction coefficient of a conventional solid lubricant coating.

FIG. 5 is a graph showing the relationship between temperature and friction coefficient of the solid lubricant coating of the present invention.

[Explanation of symbols]

1. Solid lubricating film 2 Machine elements 3 Machine elements 5 Pin 6 Block

Claims (4)

[Claims] [Claim 1] A solid lubricating film formed on the lubricated surface of an object to be lubricated, characterized by being formed by heating and solidifying a mixture of one or both of sericite and boron nitride and a coating binder. Solid lubricating coating. 2. After forming a coating film by applying a mixed mixture of one or both of sericite and boron nitride, a coating binder, and water to the lubricated surface of the object to be lubricated, the coating film is A method for producing a solid lubricant film characterized by solidifying it by heating. 3. The heating includes a heating process of heating for 1 hour at a heating rate of 100°C/hour, and a heating process of 1 hour at a temperature after the heating process.
3. The method for producing a solid lubricant coating according to claim 2, wherein the heating step is repeated to heat the solid lubricant coating for a period of time until the temperature reaches 900° C. or higher. 4. The method according to claim 2, wherein the stirred mixture is applied by spraying to the lubricated surface of the object to be lubricated at a temperature of about 100° C. or higher, and the heating is performed by the heat of the lubricated surface. A method for producing a solid lubricating film.