JPH02107818A - Multilayer sliding member and its manufacture - Google Patents

Abstract

PURPOSE:To improve sliding characteristics, above all, wear and abrasion resistance characteristics by impregnating plastic composition composed of a specific quantity of PTFE powder and a specific quantity of phenol resin powder of which almost of all are of specific diameter or less in a porous sintered metal layer and being stuck thereto and calcinated forming a sliding surface layer. CONSTITUTION:A resin composition 5 composed of ethylene tetrafluoride powder of 50 to 5 weight % and phenol resin powder of which 90% or more are of 30mum or less in a grain diameter of 5 tp 50 weight % is impregnated and stuck in and to the porous sintered metal formed on the reverse side metal 2 and then calcinated to form a sliding surface layer. The phenol resin in the sliding surface layer is heat-treated 7, 9, and 11 in the temperature of 360 to 600 deg.C. This shows excellent sliding characteristics, especially wear and abrasion resistance characteristics without damaging any mate material (shaft material).

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a multilayer sliding member and a method for manufacturing the same.

[Prior art]

Conventionally, tetrafluoroethylene resin (hereinafter referred to as rPTFEJ) or P
A multilayer sliding member in which a PTFE composition containing TFE as a main component and various fillers such as lead and lead oxide is filled and deposited is disclosed in, for example, US Pat. No. 2,689,380.
No., Special Publication No. 31-2452, Special Publication No. 39-16950
There are numbers etc.

[Problem that the invention seeks to solve]

However, the above-mentioned conventional multi-layer sliding members are still not fully satisfactory in terms of sliding properties such as wear resistance, and also have the disadvantage that there are large differences in sliding properties depending on the mating material. In view of the above-mentioned drawbacks, the present invention provides extremely good sliding properties and
Above all, the purpose is to obtain a multilayer sliding member with excellent wear resistance.

[Means for solving problems]

In order to achieve the above-mentioned object, the present invention adopts the following technical means, that is, the configuration.

That is, the present invention provides a porous sintered metal in which a resin composition comprising 50 to 95% by weight of PTFE powder and 5 to 50% by weight of phenolic resin powder of which 90% or more has a particle size of 30 μm or less is formed on a steel backing. A multi-layer sliding device characterized in that a sliding surface layer is formed by impregnating and depositing the layer and firing it, and the phenol resin in the sliding surface layer is heat-treated at a temperature of 360 to 600°C. The member and its manufacturing method.

In the above configuration, the back metal is made of a thin metal plate, and generally a structural rolled steel plate is used, but depending on the purpose of the sliding member, it may be other thin steel plates or metal thin plates other than steel plates, and these thin metal plates may be used. The corrosion resistance may be improved by applying copper plating or the like.

The porous sintered metal layer integrally formed on the backing metal is made of a copper alloy with excellent friction and wear properties such as bronze, lead bronze, or phosphor bronze. It can also be formed from aluminum alloy, iron, etc. The particle form of these alloy powders is preferably blocky or irregularly shaped.

As the PTFE that forms the main component of the resin composition, PTF [
! fine powder (for example, "Teflon 6CJ (trade name)" manufactured by DuPont Mitsui Fluorochemicals, "Polyflon F201 (trade name)" manufactured by Daikin Industries, Ltd., "Fluon CD-076, CD-126, C" manufactured by Asahi Glass Co., Ltd.)
D-4 (trade name)") is used.

The phenolic resin powder that is blended into the main component PTFE itself has wear resistance, but the phenol resin powder that is further heat-treated at a predetermined temperature has increased hardness, and this phenol resin powder can be converted into PTFH. By uniformly and finely dispersing it, it plays a role in significantly improving the wear resistance of the resin composition made of the PTFE and phenol resin.

When heat-treating this phenolic resin powder, 1. After dispersing it in PTFH, which is the main component, to form a resin composition,
Simultaneously with the firing of the resin composition, the firing temperature (360-3
(80° C.), and (2) a method of preheating at a predetermined temperature before being dispersed in i'rFU. When the latter method is adopted, the heat treatment temperature of the phenol resin powder is preferably 600° C. or lower.

The reason why the heat treatment temperature of the phenolic resin powder is set to 600°C or less is that when the heat treatment temperature exceeds 600°C, the volume resistivity value of the phenolic resin powder decreases rapidly, and the phenolic resin powder becomes mineralized (carbonized). , this is P
When dispersed in TFE, the apparent hardness of the resin composition increases, but on the other hand, the hardness of the phenolic resin powder becomes too high during friction with the mating material, causing damage to the mating material. ), this is because the adhesion of the lubricating film to the mating material is reduced, which causes a deterioration in the friction and wear characteristics.

Phenol resin powder heat-treated at a temperature of 600° C. or lower has a large amount of organic parts remaining, so the above-mentioned drawbacks do not appear and it exhibits good friction and wear characteristics.

In addition, the phenol resin powder exhibits its effect only when it is uniformly and finely dispersed in PTFH, which is the main component, and it is particularly important to make the particle size fine and uniform.

According to the experiments conducted by the present inventors, the particle size of the phenolic resin powder is such that 90% or more of the fine particles are 30 μm or less in diameter, and more preferably 90% or more of the fine particles are 20 μm or less in diameter, which are important in terms of friction and wear characteristics, moldability, etc. I got the best results with.

The phenolic resin powder used in the present invention includes ordinary novolac resins, resol resins, condensed phenol resins consisting of phenol and α,α'-dimethoxyvaraxylene, and phenol-formaldehyde resins (Japanese Patent Application Laid-open No. 177011/1983). , Japanese Patent Publication No. 58-111
No. 822), etc.

The blending amount of this phenolic resin powder with respect to PTFH is 5
~50% by weight, preferably 20-40% by weight is suitable. Sufficient filling effect (improved wear resistance) at less than 5% by weight
is not obtained, and if it is blended in an amount exceeding 50%, the properties of a phenolic resin will appear strongly, and the low friction properties of PTFH will be impaired.

The petroleum solvent added to the resin composition consisting of PTFE and phenol resin is blended at a ratio of 18 to 25 parts by weight based on 100 parts by weight of the resin composition.

If the amount of the petroleum solvent is small, the spreadability of the composition during the manufacturing process will be poor, and the impregnating adhesion of the resin composition to the porous sintered metal layer will likely be uneven. Furthermore, if too much petroleum solvent is used, not only will it be difficult to perform the deposition operation, but also the uniformity of the deposited film formed on the porous sintered metal layer will be impaired and the adhesion strength will deteriorate.

Petroleum-based solvents include naphtha, toluene, xylene, aliphatic solvents, and aliphatic/naphthenic mixed solvents.
Examples of commercially available products include Isopar (manufactured by Exxon Chemical Co., Ltd.).

Next, the manufacturing method will be explained.

PTFE powder and phenol resin powder having the above-mentioned composition are mixed while being crushed at a temperature below the room temperature transition point (19°C) of PTFH, and while maintaining this mixture at a temperature below 19°C, a petroleum solvent is added and mixed with stirring. Prepare a wet resin mixture.

One factor in imparting sufficient strength and bearing properties to the resin mixture impregnated onto the porous sintered metal layer is the preparation of a uniform wet resin mixture. This is because kneading is added to PTFH during pulverization and mixing, and PT
This is to prevent the FE particles from becoming fibrillated, significantly reducing the formability of the wet resin mixture, and preventing it from functioning as an adherent resin.

In order to obtain a multilayer sliding member in which a wet resin mixture is impregnated and deposited on a porous sintered metal layer formed on a backing metal to form a sliding surface layer, first, a wet resin mixture is applied to the porous sintered metal layer. A wet resin mixture of PTFE and phenolic resin containing a petroleum solvent is impregnated onto the porous sintered metal layer by rolling with a roller.

Next, the porous sintered metal layer is impregnated with the wet resin mixture and the back metal is heated to a temperature of 200 to 250°C and maintained at this temperature for several minutes to remove the petroleum solvent by scattering. , the dry resin mixture layer is pressed with a roller to a predetermined thickness. The pressing force at this time is approximately 300 to 6
00 kg/cm”.

Next, the entire backing metal with the dry resin mixture layer pressed by a roller is introduced into a heating furnace and heated at a temperature of 360 to 380°C for several minutes to more than 10 minutes to proceed with baking, and then taken out. Pressure is applied again with rollers to form a sliding surface layer.

This roller pressure is for adjusting dimensional variations in the range of io-'' to 10-2.

After the dimension adjustment, the backing plate on which the sliding surface layer is formed is cooled, and then passed through a correction roller for correcting undulations of the backing plate, if necessary, to form a desired multilayer board.

After cutting this multilayer board into an appropriate size, it can be used as a sliding board in a flat state, or it can be bent into a round shape and used as a cylindrical wound bush.

The figure is an explanatory diagram showing the manufacturing method of the present invention.

In the figure, 1 is a hoop material in which a steel backing 2 made of a thin steel plate integrally provided with a porous sintered metal layer is wound into a coil shape; 3.
3 is a guide roller, 4 is a hopper, and 5 is a wet resin mixture.

6.6 is a pressure roller that rolls and deposits the supplied mixture 5 on the porous sintered metal layer of the back metal 2 to a thickness of -, and in this process, the mixture is required for the final product. The resin is applied to a thickness that is 2 to 2.5 times the thickness of the resin. Most of the filling of the resin into the voids of the porous sintered metal layer progresses during this step.

7 is a hot air drying oven, and the atmospheric temperature is generally adjusted to 200 to 250°C. When the steel backing with the resin mixture layer is passed through this hot air drying oven, most of the volatile content in the resin mixture is removed.

8.8 is a sizing pressure roller that presses the dried resin mixture layer onto the porous sintered metal layer of AITM Gold 2 to a coating thickness required for the final product. In this step, the above-mentioned voids are supplementarily filled with resin, and the voids of the porous sintered metal layer are completely filled.

9 is a heating furnace for firing the resin, approximately 360-380℃
The ambient temperature is adjusted to . The steel back metal with the resin mixture layer treated with the pressure roller 8.8 passes through the furnace in a few minutes to more than ten minutes, and the resin mixture layer is baked and hardened to become a sliding surface layer. .

10.10 is a size adjusting roller, which has a thickness of 10-3 to I of the sliding surface layer impregnated and adhered to the porous sintered metal layer of the steel backing metal 2.
Fine dimensional adjustment in the range Q-"m is performed by this roller when it is hot. A coolant is passed through this roller to adjust the temperature.

Reference numeral 11 denotes a cooling device using cold water spray, etc., in which the backing metal is cooled to approximately room temperature.

Reference numeral 12 denotes a correction roller, and this correction roller 12 corrects slight waviness of the steel back metal.

13.13 is a guide roller, 14 is a coiler, and the multilayer board that has passed through the guide roller 13.13 is wound up by the coiler 14.

〔Example〕

Hereinafter, the present invention will be explained in detail with reference to Examples.

<Examples 1 to 5. Comparative Example 1 PTFE powder (trade name: 6CJ, manufactured by DuPont Mitsui Fluorochemical Co., Ltd.) was mixed with 5% by weight of spherical phenolic resin powder (trade name: UNIPEX CX, manufactured by Unitika), of which 98% or more had a particle size of 30 μm or less. 400℃ in inert atmosphere
Heat-treated product: Example 1), 20% by weight (600°C heat-treated product: Example 2), 40% by weight (4% by weight)
00°C heat-treated product: Example 4).

They were blended at a ratio of 50% by weight (400°C heat-treated product: Example 5) and 60% by weight (400°C heat-treated product: Comparative Example 1), pulverized and mixed uniformly using a Henschel mixer, and added to the mixed powder. (manufactured by Kagaku Co., Ltd.) to prepare a wet resin mixture.

The wet resin mixture is supplied onto a porous sintered metal layer formed on a steel backing made of a thin metal plate, and rolled with rollers to form a multilayer plate with a thickness of 1.20 m. After holding the multilayer board in a heat/air drying oven heated to a temperature of 200°C for 5 minutes to scatter and remove the solvent, the dry resin mixture layer was pressed with a pressure of 400 kg/cm'' using a roller to reduce the thickness. It was set to 1.05 mm.

Next, the pressurized multi-layer plate is introduced into a heating furnace for 370
After baking for 10 minutes at a temperature of 30°C, it was pressed again with a roller, and after adjusting the dimensions and correcting the undulations of the board, it was cut to a size of 30mm on the side x 30+nn+ x thickness 1.
A plate-shaped sliding member test piece of 0.05 mm was obtained.

(Comparative Example 2) 40% or more of the above spherical phenol resin powder (heat-treated product at 400°C) having a particle size of 30 μm or more was added to the PTFIE powder.
Mix it so that it is 0% by weight, and use the above method to form side 30III.
IIIX A plate-shaped sliding member test piece of 30 mm x 1.05 mm thickness was obtained (Comparative Example 3) Lead powder was mixed with the PTPE powder to a concentration of 55% by weight, and a piece with a side of 30 nv x 30 mm x r was prepared using the above method. ￥
A plate-shaped sliding member test piece with a diameter of 0.80 n+m was obtained.

A thrust test was conducted using each of the above test pieces under the following conditions, and the friction coefficient and amount of wear were measured. The results are summarized in the table below.

Test condition Speed: 45m/win Load: 10Kg/cm2 Time: 30hr Jun Dry Mating material: 545C (carbon steel for mechanical structures).

: JISG4051) A6061T8 (aluminum: JISI+4000
) SUS304 (Stainless steel: JISG4303
) The dynamic member showed a small amount of wear and a stable coefficient of friction regardless of the material of the mating shaft material tested, and particularly showed excellent sliding characteristics when the mating shaft was made of aluminum.

〔effect〕

The sliding member obtained by the present invention has the following excellent effects.

(2) It exhibits excellent sliding properties, especially wear resistance, without damaging the mating material (shaft material) of any material.

■When the mating material is aluminum, it exhibits particularly superior wear resistance compared to conventional sliding members.In the table, the upper row is the wear depth (μ11), the lower row is the friction coefficient, and the □ mark is
This shows a case where the test was stopped midway due to abnormal wear.

As is clear from the above test results, the polytetrafluoroethylene resin powder and phenol resin powder of the present invention are pulverized and mixed at a temperature below the room temperature transition point of the tetrafluoroethylene resin. The resins are pulverized and mixed without being stretched by shearing force, and the two resins are uniformly mixed.

As a result, the phenolic resin powder is uniformly dispersed within the tetrafluoroethylene resin powder, improving the sliding properties and improving the degree of impregnation of the resin into the voids of the porous sintered metal layer. In addition to mechanical bonding, adhesive curing with phenol resin is also added, which has the advantage of high adhesion strength and sufficient reinforcement of the adhered resin film itself.

■Even when wetting the resin composition by adding a petroleum solvent to tetrafluoroethylene resin and phenol resin and stirring and mixing, the process is carried out below the room temperature transition point of tetrafluoroethylene resin, so tetrafluoroethylene This method has the advantage that it is possible to completely prevent a phenomenon in which fiberization of the tetrafluoroethylene resin particles progresses due to shearing force acting on the ethylene resin, thereby inhibiting the moldability of the resin composition.

[Brief explanation of drawings]

The figure is an explanatory view showing a method for manufacturing a multilayer sliding member of the present invention. 1: Hoop material 2: Steel back metal 3: Guide roller 4: Hopper 5: Wet resin composition 6 Pressure roller 7: Hot air drying furnace 8: Pressure roller 9: Heating furnace 11; Cooling device 0: Adjustment roller

Claims (2)

[Claims] (1) Phenol resin powder 5 in which 50 to 95% by weight of tetrafluoroethylene resin powder and 90% or more of which has a particle size of 30 μm or less
A resin composition consisting of ~50% by weight is impregnated onto a porous sintered metal layer formed on a steel backing and fired to form a sliding surface layer. A multilayer sliding member characterized in that the phenolic resin is heat-treated at a temperature of 360 to 600°C. (2) (A) 50 to 95% by weight of tetrafluoroethylene resin powder and 5 to 50% by weight of phenolic resin powder of which 90% or more has a particle size of 30 μm or less at a temperature below the room temperature transition point of the tetrafluoroethylene resin. (b) adding 18 to 25 parts by weight of a petroleum solvent to 100 parts by weight of the obtained pulverized mixture, and moistening the pulverized mixture by stirring and mixing at a temperature below the room temperature transition point; , (c) a step of supplying a wet resin mixture obtained in the wetting process onto a porous sintered metal layer obtained by sintering lumpy or irregularly shaped metal powder on a thin metal plate, and (d) filling the voids in the porous sintered metal layer of the thin metal plate with the wet resin mixture and depositing it on the porous sintered metal layer; (e) filling and depositing the wet resin mixture on the porous sintered metal layer; drying the wet resin mixture layer to remove the solvent; (f) pressurizing the resin mixture layer to a predetermined adhesion thickness; (g) heating and baking the resin mixture layer; A method for manufacturing a multilayer sliding member, comprising: a step of forming a sliding surface layer;