JPH06116399A - Production of light friction material - Google Patents

Abstract

PURPOSE:To readily produce a light friction material excellent in abrasion resistance and durability and exhibiting a stable friction coefficient and a high strength by applying a surface treatment to a base material composed of a light metal such as Al and subsequently stoving a specified coating material. CONSTITUTION:A base material composed of a light metal such as aluminum (alloy) or titanium (alloy) is initially subjected to surface treatment to form a hole penetrating the base material in the direction of the thickness and a groove passing through the hole part. An organic resin coating material prepared by dispersing <=10wt.% inorganic and/or organic filler in a fluororesin-based coating material is then made to adhere to the surface of the base material and stoving is subsequently carried out at 160 to 300 deg.C, thus producing the objective material having an organic resin coating layer formed on the surface of the base material. In addition, e.g. tetrafluoroethylene polymer is used as the fluororesin for the coating material and, e.g. alumina fine particles are used as the inorganic filler. As the organic filler, e.g. PVC is used.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for manufacturing a lightweight friction material, and more particularly, as a material for controlling rotation or sliding motion in a member of a device (differential limiting device) having a friction device such as an automobile. The present invention relates to a method for manufacturing a lightweight friction material having a widely used special structure.

[0002]

2. Description of the Related Art Conventionally, a friction material of this type is generally prepared by forming a composition containing a filler or fiber exhibiting friction performance into a sheet by papermaking, rolling or press molding, and adhering this to a metal plate material as a base material. The obtained sheet-shaped friction material is processed into a desired fading material by a punching or cutting method, and is manufactured.

[0003]

In the above-mentioned conventional method for manufacturing a friction material, the sheet-shaped friction material is processed into a fading material shape by a punching or cutting method, and therefore the material yield is poor. . Moreover, regarding the friction material itself, it is difficult to obtain a friction material having stable properties because the fillers and fibers are not uniformly added and mixed.

Further, since the base material is an iron-based metal plate material, it is heavy and has a problem of rusting, so that rust prevention treatment is also required.
Furthermore, when coating the metal base material with an organic friction material to adhere the metal base material, it is necessary to blast the surface of the metal base material in order to maintain the adhesive force between the two, which requires many manufacturing steps and is industrial Was a disadvantage to

Further, in the conventional friction material using the iron-based metal plate material as the base material, it is necessary to form many oil grooves in the base material in order to secure the oil retaining property, which is not easy to process and the friction There is also a drawback that the surface is reduced by the amount of groove formation and sufficient friction characteristics cannot be obtained.

The present invention has solved the above-mentioned conventional problems, has excellent wear resistance and durability, and has a stable coefficient of friction.
It is an object of the present invention to provide a method for manufacturing a friction material that can be easily manufactured, is lightweight, and has high strength.

[0007]

According to the method for producing a friction material of the present invention, after a surface treatment is applied to a lightweight metal base material, an organic resin coating agent is adhered and then baked to form an organic resin on the surface of the base material. A method for manufacturing a friction material having a coating layer formed thereon, wherein the lightweight metal is aluminum, titanium, an aluminum alloy or a titanium alloy, and the organic resin coating agent is a fluororesin coating agent, an inorganic filler and / or Alternatively, 10% by weight or less of an organic filler is dispersed in the fluororesin coating agent, and a hole penetrating in the thickness direction of the base material and a groove passing through the hole portion are formed in the base material by surface processing. After that, the coating agent is attached to the substrate, and then baked at a temperature of 160 to 300 ° C.

The present invention will be described in detail below.

In the present invention, the lightweight metal constituting the base material is aluminum, titanium, an aluminum alloy or a titanium alloy. Among these, as an aluminum alloy, Al-Mn having an aluminum content of 95% by weight or more is used.
An alloy, an Al-Mg alloy, etc. are mentioned. Further, as the titanium alloy, Ti-A having a titanium content of 95% by weight or more is used.
1 alloy, Ti—Fe alloy, and the like.

Such a lightweight metal base material is usually formed into a disc shape (ring shape), and a plurality of through holes and grooves passing through the through holes are formed on both sides of the disc surface, and then a core is formed. Is subjected to a coating process. The through holes and grooves are provided to replenish the lightweight friction material with oil, and if the function is fulfilled, the through holes and grooves will not be formed more than necessary. The size and the number of the through holes and grooves are different depending on the size of the base material and the purpose of use, but in general, the through holes have a diameter of 0.5 to 1.
About 10 to 40 pieces of 5 mm, and the groove passing through this through hole has a width of 0.5 to 1.5 mm and a depth of 0.2 to
It is preferable to form the groove having a thickness of about 0.7 mm so as to have about 10 to 40 grooves and the total length of the groove to be about 10 to 100 mm. The grooves are formed radially from the center of the disc-shaped substrate, or are formed in a curved or straight line in the circumferential direction or the chord direction.

In the present invention, the organic resin coating agent for forming the organic resin coating layer on the surface of such a light weight metal substrate is obtained by dispersing an inorganic filler and / or an organic filler in a fluororesin coating agent. It is a thing.

The fluororesin used for the fluororesin-based coating agent is a tetrafluoroethylene polymer, 4
A fluorinated ethylene-6 fluorinated propylene copolymer, a trifluorinated ethylene polymer or the like can be used.

As the inorganic filler, alumina fine particles, magnesia fine particles, graphite fine particles (these mainly function as friction modifiers), potassium titanate (K ₂ TiO ₂ ) fibers, glass fibers,
Carbon fiber (these mainly function as a reinforcing material) can be used, and polyvinyl chloride (PVC) filler can be used as the organic filler. These fillers may be used alone or in combination of two or more.

If the amount of these inorganic fillers and / or organic fillers is too large, the surface strength of the coating layer formed tends to be slightly reduced. Therefore, the blending amount of the inorganic filler and / or the organic filler with respect to the fluororesin coating agent is preferably 10% by weight or less, and particularly preferably 4 to 8% by weight.

When the filler is fine particles, the size of the filler is preferably about 70 μm or less, and when it is a fiber, the fiber diameter is 2 to 50 μm and the fiber length is 10 to 10. It is preferably about 500 μm.

The method for adhering the fluororesin coating agent containing the inorganic filler and / or the organic filler to the lightweight metal base material is not particularly limited, but a coating method by spraying or dipping is adopted. can do.

After the coating treatment, 160 to 300 ° C.
After baking for about 10 to 30 minutes, on the surface of the lightweight metal substrate,
An organic resin coating layer having excellent wear resistance, oil resistance, and heat resistance is formed.

In the present invention, the thickness of the organic resin coating layer formed on the surface of the lightweight metal substrate is 20 to 30.
It is preferably about 0 μm. If this thickness is less than 20 μm, the strength as a friction material is insufficient, and it is 300 μm.
When it exceeds, the surface of the coating layer is unnecessarily elastic. The optimum thickness of the coating layer is 3
It is 0 to 100 μm.

[0019]

In the present invention, in order to obtain a friction material having uniform friction characteristics and high strength, a friction modifier, that is, a functional filler such as a polishing agent, a lubricant and a reinforcing material is directly applied to the base material. An organic resin coating layer having a special composition formed by mixing in an appropriate amount is provided, and the coating layer and the substrate are integrated by baking.

As this coating method, a conventional ordinary method can be adopted, and it is possible to form a coating layer having very good adhesion to a substrate, and to prevent phenomena such as peeling. Absent. Further, the solidifying step by baking the coating layer can be easily performed.

Particularly, in the present invention, the base material is aluminum,
Since it is a lightweight metal such as titanium, aluminum alloy or titanium alloy, it is light, does not have the problem of rusting, has high strength and excellent heat resistance, and also has excellent adhesion to the fluororesin of the coating agent, and also has problems of cracks and peeling. Absent. Moreover, by applying a surface treatment of through holes and grooves to such a lightweight metal base material, good oil retaining performance is secured, and by forming a uniform oil film, remarkably excellent friction characteristics are obtained.

On the other hand, the fluororesin constituting the coating layer is a polymer containing fluorine and has a strong CF.
It has a high thermal stability due to the atomic bond. However, in the coating layer mainly composed of such a fluororesin, since the inorganic filler and / or the organic filler functioning as a friction modifier, a reinforcing material, etc. are randomly oriented,
It exhibits sufficient strength against stress from all directions, and also from this point, there is no partial cracking or peeling of the friction material.

In addition, since the coating layer is excellent in strength, abrasion resistance and the like, the thickness of the coating layer can be reduced and the baking process can be further facilitated.

In the method of the present invention, the organic resin coating layer may be formed using a lightweight metal substrate which has been processed into a predetermined shape in advance, whereby processing after manufacture can be eliminated. Further, even in the case where it is processed into a predetermined shape after manufacturing, it can be processed extremely easily as compared with the conventional method using the iron-based metal base material.

[0025]

EXAMPLES The present invention will be described in more detail with reference to the following examples.

Example 1 No. 2 in Table 2 A base material (thickness 1.
8 mm) is cut into a disc shape (ring shape with an inner diameter of 50 mm and an outer diameter of 80 mm), 20 through holes with a diameter of 1 mm are evenly formed in this, and a groove (width 1 mm, depth 0.3) passing through this through hole.
(20 mm) were uniformly formed radially from the center of the disk.

Next, alumina, magnesia and graphite fine particles as inorganic fillers are used as friction modifiers, potassium titanate (K ₂ TiO ₂ ) fibers and carbon fibers are used as reinforcing materials, and polyvinyl chloride (PVC) fine particles are used as organic fillers. Was mixed with a fluororesin (“TCW-8100” manufactured by Daikin Industries, Ltd.) type coating agent to prepare three types of coating agents No. A to C having the formulations shown in Table 1. The amount of filler added is shown in Table 1.
As shown in Fig. 10, 10% for fluororesin coating agent
The range was set so as not to exceed wt%.

The alumina fine particles have an average particle size of 1
An average particle size of 0 μm is 4 as magnesia particles.
0 μm, graphite fine particles with an average particle size of 40 μm, PVC fine particles with an average particle size of 30
As the K ₂ TiO ₂ fibers, those having an average fiber diameter of 30 μm and an average fiber length of 150 μm were used, and as the carbon fibers, those having an average fiber diameter of 11 μm and an average fiber length of 100 μm were used.

[0029]

[Table 1]

The coating agents Nos. A to C thus obtained were coated on the respective substrates by the spray method in the combinations shown in Table 2 and baked to form coating layers having the thickness shown in Table 2. The baking was performed by gradually raising the temperature from 160 ° C. to 300 ° C. over 30 minutes and holding it at 300 ° C. for 30 minutes.

The amount of wear (S45
The amount of wear and the coefficient of friction when subjected to a 1000-cycle sliding test using C as a mating material were examined, and the results are shown in Table 2.

For comparison, as a conventional product, a friction material having a thickness of 500 μm is adhered to an iron-based metal substrate as shown in Table 2, N.
With respect to the friction material of No. 4 as well, the wear amount and the friction coefficient were examined in the same manner and the results are shown in Table 2.

[0033]

[Table 2]

From Table 2, it is clear that according to the method of the present invention, the thickness of the coating layer can be reduced to produce a lightweight friction material having excellent wear resistance.

[0035]

As described in detail above, according to the method for producing a lightweight friction material of the present invention, a coating layer having excellent wear resistance, oil resistance, heat resistance, etc. is formed on a surface-treated lightweight metal base material. It is a laminated friction material that is directly baked and integrated, and has excellent adhesiveness and adhesion between the base material and the coating layer,
There is no problem of peeling. The oil supply to the friction surface is uniform, and the oil film surface is always constant. Compared with the conventional product, the oil groove of the base material can be reduced and a large friction surface can be secured, so that the friction characteristics are good. It is lighter than conventional products and there is no risk of rusting. It has excellent wear resistance, durability, mechanical strength, heat resistance, etc.
The coefficient of friction is stable and good. Easy to process. It is possible to extremely easily manufacture a lightweight friction material having such excellent effects.

Claims (1)

[Claims] 1. A method for producing a friction material having an organic resin coating layer formed on the surface of a base material by surface-treating a lightweight metal base material, adhering an organic resin coating agent thereon, and then baking the surface. The lightweight metal is aluminum, titanium, an aluminum alloy, or a titanium alloy, and the organic resin coating agent is a fluororesin-based coating agent, and an inorganic filler and / or an organic filler are added to the fluororesin-based coating agent. % Or less dispersed, after forming a hole penetrating the base material in the thickness direction of the base material and a groove passing through the hole portion by surface processing, and then applying the coating agent to the base material, and thereafter , A method for producing a lightweight friction material, which comprises baking at a temperature of 160 to 300 ° C.