JPH0415228A - Sliding material - Google Patents

Abstract

PURPOSE:To prepare a sliding material which has a low friction coefficient and slides stably without damaging a mating material by filling and coating the meshes and surface of a metal network substrate with a specific lubricant compsn. CONSTITUTION:The meshes and surface of a metal network substrate are filled and coated with a lubricant comps. which comprises a polytetrafluoroethylene resin as the main component. loaded with 5-30wt.% carbon fiber and 0.1-15wt.% phosphate (e.g. calcium pyrophosphate) to give a sliding material. The comps., having a low friction coefficient, allows the material to stably slide without damaging a mating material. In addition, the compsn. has antistatic and conductive properties, eliminating the need for a means for giving conductivity in a coating process after assembling the material into a sliding part of an office automation apparatus.

Description

Detailed Description of the Invention [Field of Industrial Application] The present invention relates to a sliding material having a lubricating composition containing polytetrafluoroethylene (hereinafter referred to as PTFEJ) resin as a main component on its sliding surface. , especially at low speeds and high loads (
The present invention relates to a sliding material suitable for use under conditions (high surface pressure).

[Prior Art] PHE resins have been widely used as sliding members such as bearings due to their excellent self-lubricating properties, low coefficient of friction, and excellent chemical and heat resistance. .

However, on the other hand, sliding members made only of PTFE resin have poor wear resistance and creep resistance, so depending on the application of the sliding member, for example,
The above-mentioned drawbacks have been solved by blending a filler such as glass fiber or (1) impregnating and coating a porous sintered alloy layer integrally formed on a thin steel plate.

The sliding member having the above aspect (2) is a so-called multilayer sliding member, and the wall thickness of the member itself is thin (usually 1.
5 to 3.0 m), and the load resistance is greatly improved, making it suitable for use under low speed and high load conditions.

However, on the other hand, it is used to hold a mating material (such as a shaft) with a large gripping force (high surface pressure) and to smoothly slide and support the rotation of the mating material (in other words, the When used in applications such as the hinges of various doors or the sliding parts of ball joints for automobiles (where the clearance appears as looseness), the sliding member itself may become loose, making it difficult to use the side bottom. The problem was that I couldn't stand it.

As a sliding material that solves the above-mentioned problems, for example, there is a bearing material made of a metal mesh and a fluoropolymer sintered thereon as disclosed in Japanese Patent Publication No. 53-35107, or a bearing material that has already been proposed by the present inventors in a patent application. Showa 62-232Hl
f1 (Japanese Unexamined Patent Application Publication No. 64-79417), a sliding material ( Hereinafter, these will be referred to as "prior art").

[Problems to be Solved by the Invention] The sliding material according to the prior art described above uses a metal mesh as a base material, and due to the flexibility generated in the thickness direction, it adapts well to the surface of the mating material, and the sliding material easily adapts to the mating material. In the above-mentioned application of holding a mating member with a large gripping force and smoothly supporting the rotation of the mating member, the present invention has the effect that it can be used without causing the member to buckle or the like.

By the way, antistatic effects are required in applications where sliding materials are used, for example in the sliding parts of OA equipment, and also in the hinge parts of various doors, after the sliding material is incorporated into the part.
If the exterior part is painted, the sliding material must be electrically conductive.

However, a new problem has arisen in that the sliding materials of the prior art cannot sufficiently meet these demands.

The present invention has been made in order to further solve the above problems while effectively retaining the advantages of the prior art, and aims to obtain a sliding material that has an antistatic effect and conductivity. It is.

[Means for Solving the Problems] In order to solve the above problems, the present invention provides the following technical means.

That is, the present invention uses a metal mesh as a base material, and on the mesh and surface of the base material, polytetrafluoroethylene resin is the main component, and 5 to 30% by weight of carbon fibers and 0% phosphate are added to this as a filler. The present invention provides a sliding material that is filled and coated with a lubricating composition containing 0.1 to 15% by weight, or 0.1 to 10% by weight of a conductive material. .

In the above-mentioned structure, the net-like body constituting the base material is made of expanded metal or the aforementioned Japanese Patent Publication No. 53-351.
A metal mesh is used, such as the metal mesh disclosed in Japanese Patent No. 07.

FIG. 1 is a plan view showing an expanded metal used as a base material, and FIG. 2 is a sectional view taken along the line II in FIG. 1.

In both figures, l is an expanded metal, 2 is a mesh, 3 is each side (strand) forming the mesh 2, 4
is the joint portion (bond portion) between these strands, and t is the thickness of the expanded metal.

Although the shape of the mesh 2 of the expanded metal 1 shown in FIG. 1 is hexagonal, the shape of the mesh 2 can be rhombic, square, or any other polygonal mesh, and these are also basic. It can be used as a material.

The expanded metal 1 described above has a length of 0.1 to 1.5 mm on each side and a thickness of 0.1 to 1.5 mm. Oa+ ones are preferred.

Suitable metal materials for the expanded metal include stainless steel, phosphor bronze alloy, bronze alloy, and the like.

The metal mesh is preferably a woven wire mesh formed by weaving fine wires of copper or copper alloy, iron or iron alloy with a wire diameter of 0.1 to 0.5 mm as warp and weft threads.

Finely powdered PTFE resin, which is the main component of the lubricating composition, is used; for example, DuPont Mitsui Fluorochemical Co., Ltd.'s [
Teflon 6CJ, Teflon 6J", Asahi Glass Company's "Fluon CD-01, CD-123, CD-076, CD-
126, CD-4J, Daikin Industries'"Polyflon FI03, FIOI, FIOIE 5F201J (
The above-mentioned product names are listed as preferred.

In the present invention, carbon fibers, phosphates, and in some cases powders of conductive substances are used as fillers for the PTFE resin, which is the main component of the lubricating composition.

Carbon fibers play the role of a substance that imparts electrical conductivity to the lubricating composition and the role of compensating for the drawbacks of poor wear resistance and creep resistance of PTFE resin.

Carbon fibers include pitch-based, PAN (polyacrylonitrile)-based, and phenol-based carbon fibers treated at low temperatures (approx.
Pitch-based, PAN-based, and phenol-based carbon fibers treated at 500° C.) are used, and it is preferable to use the latter carbon fibers from the viewpoint of imparting high electrical conductivity to the lubricating composition.

A specific example of pitch-based carbon fiber is "Xyrus (trade name) J" manufactured by Nitto Boseki, a specific example of a PAN-based carbon fiber is "Pyrophil (trade name)" manufactured by Mitsubishi Rayon, and a specific example of phenolic carbon fiber. For example, Japan Kynor■
One example is "Kynol CFI6BT (trade name)" manufactured by Kogyo.

Regarding the size of the carbon fiber, that is, the diameter and length, it is preferable that the diameter is 1 to 20 - 1 and the length is 30 to 3. It is preferable that the length is around 100m from front to back.

The blending ratio of carbon fiber to the PTFE resin, which is the main component, is 5 to 30% by weight.

If the amount is less than 5% by weight, it is difficult to impart antistatic effect and conductivity to the lubricating composition, and if it is more than 30% by weight, no further improvement in conductivity can be expected, and the sliding material On the contrary, it deteriorates the friction and wear characteristics.

Phosphate itself is not a lubricating substance like graphite or molybdenum disulfide, but! By being blended with the TFε resin, it exhibits the effect of promoting film formation of the lubricating coating of the PTFE resin on the surface (sliding surface) of the mating material during sliding with the mating material. The effect of this phosphate is
Something that prevents direct contact (sliding) between the hard carbon fibers blended in the PTFε resin and the mating material, and suppresses the drawbacks of damaging the mating material of the carbon fibers and reducing the wear resistance of the sliding material. This is an important requirement for sliding materials used under dry friction lubrication.

Phosphates used in the present invention include metal salts such as tertiary phosphates, cylindrical phosphates, pyrophosphoric acid, phosphorous acid, metaphosphoric acid, and mixtures thereof.

Among these, tertiary phosphates, secondary phosphates and metal salts of pyrophosphoric acid are preferred.

As metals, alkali metals, alkaline earth metals and transition metals are used, of which alkali metals and alkaline earth metals are preferred, with lithium, calcium, magnesium and barium being particularly preferred.

Specifically, lithium phosphate (Lj3Po4), lithium hydrogen phosphate (L12HPO4), lithium pyrophosphate (L14P207), tricalcium phosphate (Ca3(P
04) 2), calcium pyrophosphate (Ca2)
P207) and calcium hydrogen phosphate (Ca HP
O4(.2 H20) ) is the most preferred phosphate.

Furthermore, hydroxyapatite represented by Ca 1o (PO4) 6 (OH)2 can also be used as a phosphate.

This phosphate is uniformly mixed with the above-mentioned PTFE resin and carbon fiber, and its particle size is preferably 2° or less on average.

Phosphate begins to have the effect of promoting the film-forming properties of the lubricating coating described above when blended in a small proportion, for example, 01% by weight, with respect to the PTFE resin, and increases in the film-forming properties up to a blending proportion of 15% by weight. The effect is maintained.

However, if the amount exceeds 15% by weight, the amount of lubricating coating formed on the surface of the mating material becomes too large, which actually reduces the wear resistance.

Therefore, the blending ratio of phosphate is 0.1 to 15% by weight.
, particularly preferably 3 to 10% by weight.

A certain proportion of conductive material powder can be added to the above-mentioned lubricating composition consisting of PTI"E resin, carbon fiber, and phosphate without reducing the friction and wear properties. Higher conductivity can be imparted to the lubricating composition by blending.

The conductive substances used in the present invention include coke, anthracite, amorphous carbon powder such as carbon black and charcoal, graphitic carbon powder such as natural graphite, artificial graphite and quiche graphite, copper powder, nickel powder, and lead. , soft metal powders such as tin and indium.

Since most of these conductive substances do not contribute to improving the friction and wear characteristics, particular care must be taken regarding their blending ratio.

In the present invention, it has been confirmed that higher conductivity can be imparted to the lubricating composition without deteriorating the friction and wear characteristics if the amount is within the range of 0.01 to 10% by weight.

Next, a method for manufacturing the sliding material will be explained.

(Preparation of lubricating composition) Based on PTFε resin powder, 5 to 30% by weight of carbon fiber and 01 to 15% by weight of phosphate, optionally 0.1
~10% by weight of conductive material powder and
'A lubricating composition is obtained by mixing at a temperature below the room temperature transition point (19° C.) of the TFE resin.

By performing this mixing at a temperature below the room temperature transition point of the PTFE resin, no shearing force is applied to the PTFE resin, preventing the resin from becoming fibrous, and a uniform mixture can be obtained.

(Manufacture of sliding material) (1) Lubricating composition 100 prepared by the method described above
15 to 20 parts by weight of a petroleum solvent are added to the lubricating composition by stirring and mixing to give wettability to the lubricating composition.

Here, naphtha, toluene, xylene, aliphatic solvents, aliphatic and naphthenic mixed solvents are used as petroleum solvents, and the commercially available product is "Exxonol" manufactured by Exxon Chemical Co., Ltd., which is an aliphatic/naphthenic mixed solvent. ” (product name).

Even when a petroleum solvent is blended into a lubricating composition and stirred and mixed to impart wettability to the lubricating composition, the stirring and mixing is performed so that PT.
This is carried out at a temperature below the room temperature transition point of the FE resin. This is to prevent the PTFε resin from being kneaded and becoming fibrous in the PTFε resin powder when the solvent is added and mixed by stirring, thereby significantly reducing the formability of the lubricating composition.

If the blending ratio of the petroleum solvent to the lubricating composition is less than 15 parts by weight, the lubricating composition will have poor spreadability in the process of filling and coating the base material consisting of a network, which will be described later, and will not adhere to the network of the base material. Filling tends to become uneven. Furthermore, if the amount exceeds 25 parts by weight, not only will filling and coating operations be difficult to perform, but the uniformity of coating thickness will be impaired, and the adhesion strength between the lubricating composition and the substrate will deteriorate.

(b) A lubricating composition imparted with wettability is spread-supplied onto a base material made of a net-like material, and rolled to fill the mesh of the base material with the lubricating composition, and the surface of the base material is coated with - After forming a coating layer of a lubricating composition such as
The petroleum solvent is dissipated and removed by keeping it in a drying oven heated to a temperature of 0.degree. C. for several minutes.

(cl) Next, the base material whose mesh and surface were filled and coated with the lubricating composition was introduced into a heating furnace, and heated at a temperature of 360 to 380°C for several minutes to more than 10 minutes to bake the lubricating composition. After that, it is taken out of the furnace and passed through rollers to adjust the dimensional variations, and is used as a sliding material.

The sliding material thus obtained is shown in FIG.

In the figure, 5 is a lubricating composition that fills the mesh 2 of the base material 1 made of a mesh (expanded metal) and is formed as a coating layer on the surface. tI indicates the thickness of the coating layer, and its range depends on the application, but is usually between 005 and 1. Om
is preferred.

[Example] Hereinafter, the present invention will be explained in detail based on examples thereof.

<Example: Engineering> (Base material) A phosphor bronze alloy plate with a thickness of 053III was subjected to expansion processing to form an expanded metal with a thickness of 043cm with a regular hexagonal mesh of length L6++m on each side (strand). This was used as the base material.

(In Figure 1, the length of code 3 is 06 mm, and the thickness of code t is 0.
．． 431) (WIi slip composition) Mitsui DuPont Fluorochemical Co.'s "Teflon 6CI J" with an average particle size of 8θ microns or less was used as the PTFE resin powder, and the PTFE resin powder had a diameter of 10-1, a length of 10G, and a caw. Carbon fiber (Nitto Boseki's "Xyrus GPMF100JL J") 5-30% by weight and calcium picrate (ca'2 P 207: manufactured by Kanto Kagaku ■) that passes through 350 meshes as a phosphate
5% by weight of the PTFE was put into a Henschel mixer.
A lubricating composition was obtained by mixing at a temperature below the room temperature transition point of the resin.

(Manufacturing process) (1) This lubricating composition 1 (for 10 parts by weight,
20 parts by weight of an aliphatic/naphthenic mixed solvent ("EFSOL" manufactured by Exxon Chemical Co., Ltd.) was blended as a petroleum solvent, and the P
Mixing at a temperature below the room temperature transition temperature of the TFE resin imparted wettability to the lubricating composition.

(b) Sprinkle and supply a lubricating composition imparted with wettability onto the base material made of the expanded metal, and apply it with a roller to fill the mesh of the base material with the lubricating composition, and at the same time, apply the lubricating composition to the surface of the base material. After forming a coating layer of a lubricating composition similar to the above, it was held in a drying oven heated to 220° C. for 5 minutes to evaporate and remove the petroleum solvent in the lubricating composition.

(cl) Next, the base material whose mesh and surface were filled and coated with the lubricating composition was introduced into a heating furnace, and heated at a temperature of 360°C for 10 minutes to bake the lubricating composition. It was taken out and used as a sliding material.

The heat of the surface coating layer of the lubricating composition of the sliding material thus obtained was 0. 13 mm (in Fig. 3, code t1
thickness).

The composition of the lubricating composition constituting the sliding material of this <Example, ■> is shown in the table.

<Example: ■> (Base material) As the base material, the same expanded metal as in the above <Example: Work> was used.

(Lubricating composition) As a PTFE resin powder, "Teflon 6CjJ" manufactured by DuPont Fluorochemical Co., Ltd. with an average particle size of 80 microns or less was used, and for this PTFE resin powder, a diameter of 10t11a was used.
1 100 m long carbon fiber (Xyrus GPMF1001LJ manufactured by Nitto Boseki ■) 1 to 20% by weight and 5% by weight of lithium pyrophosphate (Li4P207: manufactured by Kanto Kagaku ■) that passes through 350 meshes as phosphate in a Henschel mixer. and mixed at a temperature below the room temperature transition point of the PTF [resin] to obtain a lubricating composition.

Hereinafter, manufacturing steps (i), (b), and (cl) were performed in the same manner as in Example I above to obtain a sliding material.

The composition of the lubricating composition constituting the sliding material of this <Example: ■> is shown in the table.

<Example: ■> (Base material) As the base material, the same expanded metal as in the above <Example: I> was used.

(II Slippery Composition) As a PTFE resin powder, a three-piece Teflon 6CJ J manufactured by DuPont Fluorochemical Co., Ltd. with an average particle size of 8G microns or less was used, and carbon fibers (diameter 10mm and length 1ooIJ11) were used for this PTFE resin powder. Nitto Boseki's "Xyrus GPMF100ILJ') 5 to 20% by weight, 5% by weight of calcium pyrophosphate (manufactured by Kanto Kagaku ■) that passes through 350 meshes as a phosphate, and carbon black (manufactured by Mitsubishi Chemical Corporation ■: CB5) as a conductive substance.
750) in a Henschel mixer and mixed at a temperature below the room temperature transition point of the PTFE resin to obtain a lubricating composition.

Hereinafter, manufacturing steps (a), (b), and (c) were performed in the same manner as in Example 4I above to obtain a sliding material.

The composition of the lubricating composition constituting the sliding material of this <Example: ■> is shown in the table.

<Comparative example> (Base material) As the base material, the same expanded metal as in the above <Example: I> was used.

(Lubricating composition) As a PTFE resin powder, "Teflon 6CI J" manufactured by DuPont Fluorochemical Co., Ltd. with an average particle size of 80 microns or less was used, and for this PTFE resin powder,
a, length 1007ffi carbon fiber 30% by weight, ■diameter 10-1 length! 40% by weight of carbon fiber of 00ffi and 5% by weight of calcium pyrophosphate, diameter 10mm, length 1m, 40% by weight of carbon fiber of 0ffi, 5% by weight of calcium pyrophosphate and 3% by weight of carbon black as a conductive material were mixed in a Henschel mixer. into the P
A lubricating composition was obtained by mixing at a temperature below the room temperature transition point of the TFE resin.

Hereinafter, manufacturing process (1) (bl (c)) was manufactured in the same manner as in the above <Example: I> to obtain a sliding material.

The composition of the lubricating composition constituting the sliding material of Comparative Example is shown in the table below.

Next, the results of testing the frictional wear characteristics and volume resistivity (Ω·cm,) of the sliding materials obtained in the Examples and Comparative Examples described above will be described.

<Friction and wear characteristics> Friction and wear characteristics were measured under the sliding conditions shown below.

(Sliding conditions) Sliding speed 5 m/min Load 100 kgf/cm2 Test time 8 hours Lubrication Non-lubricated material Carbon steel for machine structure (S45C) The friction coefficient from the start of the test to the end of the test The fluctuation values are shown, and the amount of wear was measured after 8 hours of testing.

<Volume resistivity> Regarding the volume resistivity, the volume resistivity in the direction perpendicular to the surface of each sliding material was measured using a Mitsubishi Yuka ■ resistivity needle (Lolesjer AP Mcp-T4 [10
).

The table shows the friction and wear characteristics and volume resistivity of each sliding material.

From the test results, the sliding materials of Examples I to 2 exhibited stable performance with a low coefficient of friction throughout the test period, and the amount of wear of the sliding materials after the test was also extremely small.

Example: Even though the sliding material made of No. 6 contained 30% by weight of carbon fiber, no damage was observed on the surface of the mating material after the test.

Moreover, the volume resistivity showed a value of 108 to 10-3.

In general, the antistatic effect required for the sliding parts of OA equipment is a volume resistivity of l- or less, and the antistatic effect is required for the exterior painting process that is carried out on the painting line after the sliding material is incorporated into the door hinge. Considering that the electrical conductivity is a volume resistivity of 10'' or less, this is a sufficiently satisfactory performance.

On the other hand, the sliding material of the comparative example is a very excellent material in terms of antistatic effect and conductivity, but in terms of friction and wear characteristics, it has a high coefficient of friction, and the amount of wear does not reach the base material. Additionally, many thin streak-like damages were observed on the surface of the mating material.

In the above examples, an example was explained in which expanded metal was used as the base material made of a net-like body, but the same effect can be achieved even if a metal mesh formed by weaving fine metal wires in the vertical and horizontal directions is used as the base material. is obtained.

[Effects] The present invention has the above-described configuration and has the following unique effects.

■The lubricating composition filled and coated on the mesh and surface of the base material, which consists of a net-like body, exhibits stable performance with a low coefficient of friction without damaging the other material when sliding with the other material. Due to the flexibility that occurs in the thickness direction, it conforms well to the surface of the mating material, and can be used in sliding applications to grip the mating material with a large gripping force and smoothly support the rotation of the mating material, without causing material settling. can be used.

■Since the lubricating composition filled and coated on the mesh and surface of the base material has an antistatic effect and conductivity, it is also conductive in the coating process that is performed after the sliding parts and sliding materials of various OA equipment are installed. Does not require any means to give sex,
The range of uses will be greatly expanded.

[Brief explanation of the drawing]

Figure 1 shows the net-like body (expanded metal) that makes up the base material.
2 is a sectional view taken along the line I-I in FIG.
The figure is a sectional view showing the sliding material. 1... Reticular body (expanded metal), 2...
...mesh, 3...side (strand),
4... Connection part (bond part), 5... Lubricating composition. Figure 3

Claims (6)

[Claims] (1) A metal net-like body is used as a base material, and the net and surface of the base material is made of polytetrafluoroethylene resin as a main component, and 5-30% by weight of carbon fiber and 0.1-30% of phosphate as a filler. A sliding material, characterized in that it is filled and coated with a lubricating composition containing 15% by weight. (2) The sliding material according to claim 1, wherein the lubricating composition further contains 0.1 to 10% by weight of a conductive substance. (3) The conductive substance is one or two of amorphous carbon powder, graphitic carbon powder, copper powder, nickel powder, and soft metal powder.
The sliding material according to claim 1 or 2, wherein the sliding material is selected from at least one species. (4) Claim 1, wherein the net-like body constituting the base material is an expanded metal or metal mesh with a regular mesh.
The sliding material according to any one of items 3 to 3. (5) Any one of claims 1 to 4, wherein the phosphate is a metal salt selected from one or more of tertiary phosphoric acid, diphosphoric acid, pyrophosphoric acid, phosphorous acid, and metaphosphoric acid. The sliding material described in item 1. (6) Claim 1 in which the phosphate is selected from one or more of lithium phosphate, lithium hydrogen phosphate, lithium pyrophosphate, tricalcium phosphate, calcium pyrophosphate, calcium hydrogen phosphate, and hydroxyapatite. 6. The sliding material according to any one of items 5 to 5.