JPH0819952B2 - Sliding material and manufacturing method thereof - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial field of use] The present invention relates to a sliding material having a lubricating composition containing a polytetrafluoroethylene (hereinafter referred to as “PTFE”) resin as a main component on a sliding surface, and a sliding material thereof. The present invention relates to a manufacturing method, and particularly to a sliding material suitable for being used under conditions of low speed and high load (high surface pressure).

[Conventional technology]

Conventionally, PTFE resins have been widely used as sliding members such as bearings because they have excellent self-lubricating properties, a low friction coefficient, and excellent chemical resistance and heat resistance.

However, on the other hand, since sliding members made of only this PTFE resin have poor wear resistance and creep resistance, fillers such as graphite, molybdenum disulfide, and glass fiber may be added depending on the application of the sliding member. The porous sintered alloy layer integrally formed on a thin steel plate is impregnated and coated to solve the above-mentioned drawbacks.

[Problems to be solved by the invention]

The sliding member having the above-described aspect is what is called a multi-layer sliding member, and the thickness of the member itself is small (usually 1.5
It is suitable for use under low speed and high load conditions because the load resistance is greatly improved.

However, it is used for holding a mating material (such as a shaft) with a large gripping force (high surface pressure) and smoothly supporting the rotation of the mating material (in other words, the clearance between the mating material and the mating material remains as backlash). There is a problem that when the material is used), for example, when it is used under more severe conditions such as hinges of various doors or ball joints for automobiles, the members are settled and cannot be used at all.

It is an object of the present invention to obtain a sliding material that exhibits excellent friction and wear characteristics without causing fatigue of the member even under the above-mentioned severe conditions.

[Means for solving problems]

In order to achieve the above-mentioned object, the present invention adopts the following configurations (technical means).

That is, an expanded metal made of stainless steel or phosphor bronze alloy having a regular mesh is used as a substrate, and the mesh and the surface of the substrate are made of polytetrafluoroethylene resin as a main component and a heat-treated phenol resin as a filler and / or A sliding material, characterized by being filled and coated with a lubricating composition containing 5 to 30% by weight of an addition polymerization type polyimide resin, and a method for producing the same.

In the present invention, the expanded metal forming the base is a fixed lower mold having a linear blade, a wavy shape, a trapezoidal shape,
A metal plate is fed between the movable upper mold having triangular blades or the like at right angles to the fixed lower mold blade or obliquely to the fixed lower mold blade to move the movable upper mold up and down. The metal plate is reciprocated in the same direction to make notches, and at the same time, the notches are opened to form a regular mesh row.

FIG. 1 is a plan view showing an expanded metal formed by using a trapezoidal blade for the movable upper die in the above-described method, and FIG. 2 is a sectional view taken along line I-I of FIG. is there.

In the figure, 1 is an expanded metal, 2 is a mesh, 3 is each side (strand) forming the mesh 2, 4 is a connecting portion (bond part) between these strands, and t is a thickness of the expanded metal 1. That's it.

Although the mesh 2 of the expanded metal 1 shown in FIG. 1 has a regular hexagonal shape, the mesh 2 has a rhombic shape, a rectangular shape, etc. by changing the shape of the movable upper die as described above. Polygonal meshes can be formed and these can also be used as substrates.

In the present invention, the expanded metal 1 described above has a length of each side (strand) of 0.1 to 1.5 mm and a thickness of
0.1 to 10 mm is used.

Then, stainless steel or phosphor bronze alloy is used as the metal material forming the expanded metal. A metal having a relatively large elongation rate, for example, aluminum, from the easiness of manufacturing to form an expanded metal from a metal plate,
Lead or alloys thereof are recommended, but cannot be used in terms of strength in sliding materials used under high load conditions such as the present invention.

A fine powder of PTFE resin which is the main component of the lubricating composition is used. For example, "Teflon 6CJ, Teflon 6J" manufactured by Mitsui DuPont Fluorochemical Co., Ltd., "Fluon CD-0" manufactured by Asahi Glass Co., Ltd.
1, CD-123, CD-076, CD-126, CD-4 "and" Polyflon F103, F101, F101E, F201 "(all of which are trade names) manufactured by Daikin Industries, Ltd. are preferred.

In the present invention, a heat-treated phenol resin powder and / or an addition polymerization type polyimide resin powder is used as a filler for the above-mentioned PTFE resin which is the main component of the lubricating composition.

This heat-treated phenol resin powder and / or addition polymerization type polyimide resin powder makes full use of the self-lubricating property and low friction property of the PTFE resin as the main component,
It is a filler that plays a significant role in improving the abrasion resistance, which is a drawback of PTFE resin.

The heat-treated phenol resin powder is obtained by heat-treating a novolak resin or a resole resin in advance in an inert gas (for example, nitrogen gas) atmosphere at a temperature of 300 to 600 ° C. Hardened, Micro Vickers hardness is about 45 ~ 120
Can be increased to the range of. The heat treatment time varies depending on the treatment temperature, the type and amount of phenol resin to be treated,
It is usually 1 to 4 hours.

Examples of the heat-treated phenol resin powder include “Bellpearl” (trade name) manufactured by Kanebo Co., Ltd.

As the addition-polymerization type polyimide resin powder, a preferable example is a polyamino bismaleimide resin which is commercially available from Rhone-Poulenc under the trade name of "Kelimide" as a raw resin for molding compound. This polyamino bismaleimide resin is A thermosetting polyimide resin having the following chemical formula and produced by addition polymerization of maleic anhydride and diaminodiphenylmethane.

Then, the heat-treated phenol resin powder and / or addition polymerization type polyimide resin powder as a filler is
It is mixed with the PTFE resin powder as the main component in a proportion of 5 to 30% by weight.

If it is 5% by weight or less, it is insufficient to improve the abrasion resistance of the PTFE resin, and if it is 30% by weight or more, the low friction property of the PTFE resin is deteriorated.

Next, a method of manufacturing the sliding material will be described in the order of steps.

(A) As a substrate, an expanded metal made of stainless steel or phosphor bronze alloy having a regular mesh array shown in FIG. 1 is prepared.

(B) 70 to 95% by weight of PTFE resin powder and 5 to 30% by weight of phenol resin powder and / or addition-polymerization type polyimide resin powder heat-treated as a filler, at a temperature below the room temperature transition point (19 ° C.) of the PTFE resin. The mixture is pulverized and mixed to obtain a lubricating composition.

By carrying out this pulverization / mixing at a temperature not higher than the room temperature transition point of the PTFE resin, fibrous formation of the PTFE resin is prevented without applying shearing force to the PTFE resin, and a uniform mixture can be obtained.

(C) 15 to 25 parts by weight of a petroleum solvent is added to 100 parts by weight of the thus obtained lubricating composition, and the mixture is stirred and mixed to impart wettability to the lubricating composition.

Here, as the petroleum-based solvent, naphtha, toluene, xylene, an aliphatic solvent, an aliphatic / naphthene-based mixed solvent is used, and as a commercial product, an aliphatic / naphthene-based mixed solvent manufactured by Exxon Chemical Co., Ltd. (Brand name) and the like.

Even when a petroleum solvent is added to the lubricating composition and the mixture is agitated and mixed to impart wettability to the lubricating composition, the agitated mixing is performed using PTFE.
It is carried out at a temperature below the room temperature transition point of the resin. This is because the PTFE resin is kneaded when the solvent is added and mixed by stirring.
This is to prevent the FE resin powder from becoming fibrous and significantly reducing the molding property of the lubricating composition.

Then, if the amount of the petroleum solvent added to the lubricating composition is 15 parts by weight or less, the spreadability of the lubricating composition in the impregnation coating step on the expanded metal described later is poor, and unevenness easily occurs in the impregnation of the expanded metal mesh. Become. Also, 25
Addition of more than parts by weight not only makes impregnation coating work difficult, but also impairs uniformity of coating thickness and deteriorates adhesion strength.

(D) A wet composition having a wettability is sprinkled and supplied onto the expanded metal, and the roller is rolled to fill the mesh of the expanded metal with the lubricating composition, and the surface of the metal is uniformly lubricated. After forming the coating layer of
The petroleum solvent is dissipated and removed by keeping it in a drying oven heated to a temperature of 0 to 250 ° C. for several minutes.

(E) Then, the expanded metal having the mesh and surface impregnated and coated with the lubricating composition is introduced into the heating furnace, and 360 to 3
After heating the lubricating composition by heating at a temperature of 80 ° C. for several minutes to ten minutes, the lubricating composition is taken out of the furnace and passed through rollers to adjust the dimensional variation to obtain a sliding material.

The sliding material obtained through the above steps is shown in FIG.

In the figure, 5 is a lubricating composition in which the mesh 2 of the expanded metal 1 is filled and a coating layer is formed on the surface, and t ₁
Is the thickness of the coating layer.

FIG. 4 is a vertical cross-sectional view showing a sliding material obtained through the above-described manufacturing process, using an expanded metal 1 ′ in which a flat surface portion 6 is formed at a sharp tip portion of a bonding portion (bond portion) 4 as a substrate. Is.

By using such an expanded metal 1'as a base, the load is not concentrated on the sharp tip of the joint 4 of the expanded metal 1'when sliding with the mating material, and the load is evenly applied on the entire sliding surface. Therefore, the coating layer of the lubricating composition is not destroyed, and even if the coating layer of the lubricating composition is worn and shifts to sliding contact with the substrate, the sharpened tip of the joint of the expanded metal is supported. There is no problem that the surface of the mating material is damaged in some parts.

〔Example〕

 Hereinafter, the present invention will be described in detail based on examples thereof.

(Example: I) (Substrate) A phosphor bronze alloy plate having a plate thickness of 0.3 mm was subjected to an expanding process to form an expanded metal having a thickness of 0.43 mm with a regular mesh of regular hexagons having a side (strand) of 0.6 mm, This was used as a base.

(In FIG. 1, the length of the code 3 is 0.6 mm, and the thickness of the code t is 0.4 mm.
3mm) (Lubrication composition) "Teflon 6CJ" from Mitsui DuPont Fluorochemicals with an average particle size of 80 microns or less is used as PTFE resin powder,
To 90% by weight of this PTFE resin powder, 10% by weight of addition-polymerization type polyimide resin powder (“Kelimide” manufactured by Rhone-Poulin) that passes through 150 mesh was put into a Henschel mixer and the room temperature transition point of the PTFE resin or less Crush at the temperature of
The mixture was mixed to obtain a lubricating composition.

(Manufacturing process) (a) To 100 parts by weight of this lubricating composition, 20 parts by weight of an aliphatic / naphthene-based mixed solvent (“Exsol” manufactured by Exxon Chemical Co.) as a petroleum-based solvent was added, and the room temperature transition of the PTFE resin was performed. Mixing at temperatures below the point provided the lubricating composition with wettability.

(B) A lubricating composition provided with wettability is sprinkled and supplied onto the expanded metal, roller-rolled to fill the mesh of the expanded metal and form a uniform coating layer on the surface, and then 220 ° C. It was kept for 5 minutes in the drying oven heated to the temperature of 1 to remove the petroleum solvent in the lubricating composition by scattering.

(C) Then, the expanded metal having the mesh and surface impregnated and coated with the lubricating composition was introduced into a heating furnace, and the temperature was changed to 360 ° C.
After heating the lubricating composition by heating at the temperature of 10 minutes for 10 minutes, the lubricating composition was taken out of the furnace and used as a sliding material.

The thickness of the surface coating layer of the lubricating composition of the sliding material thus formed is 0.13 mm (thickness t _{1 in} FIG. 3).

(Example: II) (Substrate) The same expanded metal as in the above (Example: I) was used.

(Lubrication composition) "Teflon 6CJ" from Mitsui DuPont Fluorochemicals Co., Ltd. with an average particle size of 80 microns was used as the PTFE resin powder.
To 90% by weight of TFE resin powder, 10% by weight of heat-treated phenol resin powder (“Bellpearl H300” manufactured by Kanebo Co., Ltd.) having an average particle size of 15 μm or less was charged into a Henschel mixer, and the PTFE resin was cooled to room temperature. Crush at a temperature below the transition point
The mixture was mixed to obtain a lubricating composition.

Hereinafter, the manufacturing steps (a), (b), and (c) were the same as those in the above (Example: I) to manufacture a sliding material.

(Example: III) (Substrate) A stainless steel plate (SUS305) with a plate thickness of 0.3 mm was expanded to form a 0.43 mm thick expanded metal with a regular hexagonal mesh of 0.6 mm on a side (strand). This was used as a base. (In FIG. 1, the length of the code 3 is 0.6 mm, and the thickness of the code t is 0.43 mm.) (Lubricating composition) and (Production process) are the same as those described in (Example: I).
A sliding material was obtained in the same manner as.

(Example: IV) (Substrate) The same expanded metal as in (Example: I) above was used.

(Lubrication composition) "Teflon 6CJ" from Mitsui DuPont Fluorochemicals Co., Ltd. with an average particle size of 80 microns was used as the PTFE resin powder.
To 85% by weight of TFE resin powder, 7.5% by weight of addition-polymerization type polyimide resin powder (“Kelimide” manufactured by Rhone-Poulin) that passes through 150 mesh and heat-treated phenol resin powder with an average particle size of 15 microns or less (bell spinning ( 7.5% by weight of "Bellpearl H300" manufactured by K.K. Co., Ltd. was put into a Henschel mixer and pulverized and mixed at a temperature not higher than the room temperature transition point of the PTFE resin to obtain a lubricating composition.

Hereinafter, the manufacturing steps (a), (b), and (c) were the same as those in the above (Example: I) to manufacture a sliding material.

(Example: V) (Substrate) A phosphor bronze alloy plate having a plate thickness of 0.3 mm was subjected to an expanding process to form a 0.43 mm thick expanded metal having a regular hexagonal mesh with a side (strand) of 0.6 mm. The surface of the expanded metal was pressed to form a flat portion at the tip of the joint of the expanded metal, and this was used as a substrate. (The length of the code 3 in FIG. 1 is 0.6 mm, and the thickness of the code t ′ in FIG. 4 is 0.40 mm.) Hereinafter, the (lubricating composition) and the (manufacturing process) are the same as those in (Example: I). A sliding material was manufactured in the same manner as in.

(Comparative Example) (Substrate) The same expanded metal as used in (Example: I) above was used.

(Lubrication composition) "Teflon 6CJ" from Mitsui DuPont Fluorochemicals Co., Ltd. with an average particle size of 80 microns was used as the PTFE resin powder.
With respect to 90% by weight of TFE resin powder, 5% by weight of glass short fibers and 5% by weight of graphite powder were charged into a Henschel mixer,
The PTFE resin was pulverized and mixed at a temperature below the room temperature transition point to obtain a lubricating composition.

Hereinafter, the (manufacturing process) was manufactured in the same manner as the above-mentioned (Example: I) to obtain a sliding material (comparative example).

Next, the results of testing the frictional wear characteristics of the sliding materials obtained in Examples I to V described above and the sliding materials obtained in Comparative Examples under the sliding conditions shown below will be described.

<Sliding conditions> Sliding speed 5m / min Load 60kg / cm ² accumulated every 1 hour Accumulated load Test time 8 hours Moisture-lubricated non-lubricating material Mechanical structural carbon steel (S45C) The results of measuring the relationship between the load and the friction coefficient and the amount of wear of the sliding material after the 8-hour test are shown.

From the test results, the sliding members of Examples: I to V: showed a low friction coefficient throughout the test time, and the amount of wear of these sliding materials after the test was extremely small. When the surface of the mating material after the test was observed, no damage was observed.

On the other hand, in the sliding material of the comparative example, the friction coefficient sharply increased at a cumulative load of 360 kg / cm ² , and the wear amount became extremely large. Then, cut edges due to crushing were observed on the side (strand) forming the expanded metal mesh of the substrate of this product.
In addition, scratch marks due to the glass fibers in the lubricating composition were recognized on the surface of the mating material.

〔effect〕

The present invention is configured as described above and has the following unique effects.

By using an expanded metal made of stainless steel or a phosphor bronze alloy as the base, the flexibility generated in the thickness direction of the expanded metal fits well to the surface of the mating material and holds the mating material with a large clamping force. It can be used in a sliding application for smoothly supporting the rotation and the like of a material without causing a set or the like.

Since the expanded metal as the substrate has excellent shaping properties, it can be easily processed according to the shape of the mating material.

The lubricating composition filled and coated on the mesh and surface of the expanded metal has excellent friction and wear characteristics when sliding with the mating material, and in combination with the above effect, holds the mating material with a large clamping force. In addition, it exerts its performance regardless of the sliding application that smoothly supports the rotation of the mating material.

[Brief description of drawings]

FIG. 1 is a plan view showing an example of an expanded metal constituting a base body, FIG. 2 is a sectional view taken along the line II of FIG. 1, FIG. 3 is a sectional view showing a sliding material, and FIG. It is sectional drawing which shows the other Example of a material. 1, 1 ': Expanded metal 2: Mesh, 3: Edge (strand) 4: Bonding part, 5: Lubricating composition 6: Flat surface t, t': Thickness of expanded metal

 ─────────────────────────────────────────────────── --Continued from the front page Examiner Hitoshi Akizuki (56) References JP-A-63-57919 (JP, A)

Claims (2)

[Claims] Claims: 1. A base is an expanded metal made of stainless steel or phosphor bronze alloy having a regular mesh, and the mesh and the surface of the base are made of a polytetrafluoroethylene resin as a main component and a heat-treated phenol as a filler. A sliding material which is filled with and coated with a lubricating composition containing 5 to 30% by weight of a resin and / or an addition polymerization type polyimide resin. 2. A step of (a) preparing an expanded metal made of stainless steel or a phosphor bronze alloy having a regular mesh as a substrate, and (b) heat-treating as a filler with 70 to 95% by weight of polytetrafluoroethylene resin powder. Phenolic resin powder and / or addition polymerization type polyimide resin powder 5-30% by weight
Petroleum oil to 100 parts by weight of the lubricating composition obtained in the step (b) above, by pulverizing and mixing the polytetrafluoroethylene resin at a temperature below the room temperature transition point of the polytetrafluoroethylene resin to obtain a lubricating composition. A step of adding 15 to 25 parts by weight of a system solvent and mixing with stirring to impart wettability to the lubricating composition; and (d) expanding the lubricating composition provided with the wettability in step (a) above. After spraying and supplying onto the metal, rolling and rolling to fill the mesh of the expanded metal with the lubricating composition and forming a uniform coating layer of the composition on the surface of the expanded metal, the lubricating composition is applied. A method for producing a sliding material, which comprises a step of drying and removing the solvent by diffusion, and a step of (e) heating and firing a lubricating composition filled on the mesh and surface of the expanded metal. .