JPH08219209A - Facing frictional material and manufacture thereof - Google Patents

Abstract

PURPOSE: To provide a facing frictional material which is excellent in its wear resistance and μ-V characteristics. CONSTITUTION: A frictional material is prepared by forming a frictional layer including the frictional material and organic binder of polyamidoimido group resin, on the surface of a metallic core plate. Three kinds of carbon fiber, alumina fiber and aramido fiber are used together as the frictional material and the contents of the frictional material and resin are respectively set to 30-60 and 40-70, in weight %. The entanglement structure of strong three- dimensional fiber is formed by excessively mixing a fiber kind by the combination of different fibers, and also a clearance through which oil can be moved is formed. The carbon fiber and the aramido fiber effectively function to improve the strength of the entanglement structure, and the alumina fiber effectively functions to stabilize the coefficient of friction. The polyamidoimido group resin can be sufficiently strongly fix the fiber kind of the frictional material, and also excellent in its adhesiveness to the core plate and heat resistance.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a facing friction material and a method for manufacturing the same, and more particularly, to a friction member of a device having a friction mechanism such as a wear-resistant material for machines and home appliances, a friction facing material for automobiles and the like. The present invention relates to a useful facing friction material and a manufacturing method thereof.

[0002]

2. Description of the Related Art Conventionally, a friction material of this kind generally has a core plate made of a vapor-type friction material obtained by forming a composition containing a filler or a fiber exhibiting friction performance into a sheet or by roll forming or press forming. It is manufactured by adhering to a metal plate.

Further, there has also been proposed a facing material in which a coating liquid containing a filler or fibers is applied to a metal plate material serving as a core plate to form a friction layer.

[0004]

The friction material using the above-mentioned conventional paper-based friction material has the following drawbacks.

Conventional paper-based friction materials are inferior in wear resistance and heat resistance, and do not exhibit the characteristics adapted to recent high performance specification specifications. As for the friction material itself, the addition of fillers and fibers and the mixed state are not uniform, and it is difficult to obtain a friction material having stable properties. Friction materials that use iron-based metal plate as the core plate require many oil grooves to be formed in the core plate in order to ensure the rapid movement of oil, which is not easy to process and the processing cost is high. , There is a problem as an industrial material.

The friction characteristics are also not sufficient.

In the case of a facing type friction material, due to the relationship between the sliding speed (V) and the friction coefficient (μ), the friction coefficient increases as the sliding speed increases (hereinafter, this characteristic will be referred to as “μ-V characteristic”). Is a necessary condition. Conventional paper-based friction materials have a proportional relationship between the sliding speed and the friction coefficient, but have poor wear resistance and are difficult to put into practical use under severe operating conditions. The step of adhering the friction material and the core plate is complicated, and there is a problem of peeling of the friction material.

On the other hand, a facing material having a friction layer formed by coating has no problem of the friction material adhering step and peeling and has excellent wear resistance, but in terms of the relationship between the sliding speed and the friction coefficient, the sliding speed However, there is a problem that the coefficient of friction does not become as large as expected even if becomes larger, and sometimes shows a decreasing tendency.

The present invention solves the above-mentioned conventional problems and is a coating type facing friction material having excellent wear resistance and friction characteristics, and particularly a facing friction material having excellent μ-V characteristics and a method for producing the same. The purpose is to provide.

[0010]

The facing friction material according to claim 1 is a facing friction material comprising a metal core plate and a friction layer containing an organic binder made of a polyamideimide resin on the surface of a metal core plate. The friction material is composed of carbon fiber, alumina fiber and aramid fiber, and the content of the friction material in the friction layer is 30 to 60.
The content of the polyamide-imide resin is 40 to 7 in% by weight.
It is characterized by being 0% by weight.

A method of manufacturing a facing friction material according to a second aspect is a method of manufacturing the facing friction material according to the first aspect, wherein carbon fiber, alumina fiber and aramid fiber are mixed with a polyamide-imide resin and coated. A liquid is prepared and the coating liquid is applied to a metal core plate.

The present invention will be described in detail below.

In the present invention, the metal material constituting the core plate is not particularly limited, and the present invention can be applied to any metal material core plate, but preferably, the inexpensive iron generally used conventionally is used. Examples include alloys and lightweight aluminum alloys.

In the present invention, the surface of the metal core plate on which the friction layer is formed is slit, if necessary, and then the friction layer is formed by the method described later. By slitting the metal core plate, it is possible to appropriately supply or remove the oil in the oil during frictional sliding during actual use.

Further, in such a metal core plate, the surface on which the friction layer is formed is subjected to a blast treatment or the like as necessary to increase the surface roughness, so that the adhesive strength of the friction layer coated on this surface is increased. Can be increased.

In the present invention, as friction material, carbon fiber, alumina fiber and aramid fiber are used.
Seed fibers are used. Carbon fibers having an average diameter of 6 to 10 μm and an average length of 20 to 100 μm are preferably used. The alumina fiber has an average diameter of 2 to 5 μm and an average length of 50 to 150 μm.
The aramid fibers having an average diameter of 5 to 15 μm and an average length of several mm to 30 mm are preferably used.

The carbon fiber, the alumina fiber and the aramid fiber can be used in an arbitrary ratio. By using the carbon fiber, the alumina fiber and the aramid fiber in combination, the carbon fiber, the aramid fiber and the When used in combination, a large amount of carbon fiber, alumina fiber and aramid fiber as a friction material can be blended.

In the present invention, the amount of the friction material composed of carbon fiber, alumina fiber and aramid fiber in the friction layer is in the range of 30 to 60% by weight. When the proportion of the friction material is less than 30% by weight, the durability of the friction layer formed is not sufficient. In the present invention, it is possible to mix a large amount of friction material up to 60% by weight by using different fibers in combination, but if the amount is more than 60% by weight, the uniform dispersibility and coating property of the coating liquid will be poor. Particularly, in the present invention, it is preferable to add a large amount of carbon fiber, alumina fiber and aramid fiber in a total amount of 30 to 60% by weight.

As mentioned above, the carbon fiber, the alumina fiber and the aramid fiber may be blended in any proportion, but preferably 0.2 to 1 times by weight of the alumina fiber and the aramid are used. 1 to 3 times the weight of the fiber.

Generally, in the friction layer of the facing friction material, it is necessary to mix inorganic fine particles such as carbon fine particles as a friction adjusting material. In the present invention, the alumina fiber used as the friction material has a friction adjusting function. Therefore, it is not necessary to add a friction modifier.

In the present invention, a polyamide-imide resin is used as the binder resin, but the polyamide-imide resin fixes fibers as a friction material stably and firmly,
Moreover, since it strongly adheres to the core plate and has excellent heat resistance, it is suitable as a binder resin for the friction layer.

In the method of the present invention, the above components are sufficiently dispersed and mixed at a predetermined ratio to prepare a paste-like coating liquid, and the coating liquid is applied to the surface of the core plate. In the present invention, as described above, a large amount of fibers as a friction material can be blended, but if the viscosity of the coating liquid becomes high due to a large amount of friction material blending, it cannot be applied by the spray method. In the case of a sufficiently viscous coating liquid, it is preferable to apply it by a roller method or a method similar thereto.

After coating, in order to enhance the adhesiveness between the binder resin and the core plate, the adhesiveness between the binder resin and various additives, and the strength of the friction layer,
Baking is performed at 300 ° C. for about 10 to 60 minutes.

In the present invention, it is preferable that the friction layer thus obtained has a thickness of 100 to 500 μm, but in the coating method such as the roller method, it is 100 to 500 μm.
Since it is difficult to apply to a coating thickness of 500 μm, after applying to about 500 to 1000 μm and baking,
It is advantageous to grind the surface to a thickness of 100-500 μm. If the thickness of the formed friction layer is less than 100 μm, sufficient friction characteristics cannot be obtained, and if it exceeds 500 μm, there is no difference in friction characteristics, and the thickness of the friction layer is undesirably increased.

[0025]

The inventors of the present invention have proposed a coating liquid additive and a manufacturing method for the coating type facing friction material in order to develop the μ-V characteristic, that is, the characteristic that the friction coefficient maintains an increasing tendency as the sliding speed increases. As a result of various studies, the surface condition and the layer structure of the friction layer of the facing friction material have a great influence on the μ-V characteristic, and the surface condition of the friction layer has unevenness and the friction The layer should be porous from this surface inwards.
It has been found that it becomes an important requirement for improving the −V characteristic.

That is, in order to obtain the frictional characteristics desired as a facing friction material, the lubricating oil can be promptly removed from the surface of the friction layer, the friction layer itself is slightly elastically deformed, the surface is wear-resistant, and the tensile strength is high. High strength is an essential condition. Of these, conventional removal of lubricating oil includes conventional slitting and porosity imparting according to the present invention.

In the present invention, by making the friction layer porous, the lubricating oil content of the friction surface is rapidly moved to the inside of the friction layer at a high sliding speed, thereby lowering the friction coefficient of the friction surface. Good μ-V characteristics are ensured without performing Further, the friction layer is made porous, and high-strength fibers such as carbon fibers and aramid fibers are mixed in a sufficiently large amount and uniformly to improve μ-V characteristics and various characteristics such as abrasion resistance.

In the present invention, carbon fibers and aramid fibers are used together as a means for blending a large amount of these high strength fibers. By using carbon fiber and aramid fiber in combination as described above, it becomes possible to blend a large amount of long fibers, which has been impossible in the past, and to arbitrarily control the blending ratio of fibers and the thickness of the coating layer. Became possible.

The effects of the combined use of carbon fiber, alumina fiber and aramid fiber in the present invention are as follows.

That is, although carbon fiber is a short fiber and has high rigidity, it is impossible to mix a large amount with carbon fiber alone, but by using aramid fiber in combination with this, the degree of freedom of mixing is increased, and thus a large amount of carbon fiber is mixed. It will be possible.

This is because when carbon fibers and aramid fibers are used in combination, different kinds of fibers are three-dimensionally entangled, and in the present invention, the fibers are entangled with each other and the binder is used. It is firmly fixed by a certain polyamide-imide resin to form a high-strength friction layer. In addition, the three-dimensional entanglement forms a fine gap in the friction layer, which allows the oil to move and improves the friction characteristics. Also, by using together with alumina fiber,
It is possible to obtain a good friction adjusting function, and it becomes unnecessary to mix inorganic fine particles as a friction adjusting material.

In the present invention, carbon fibers, alumina fibers and aramid fibers are combined to form a strong three-dimensional entangled structure of fibers by blending a large amount of fibers and a gap in which oil can move. To form. Among the fibers, carbon fiber and aramid fiber effectively function to improve the strength, and alumina fiber effectively functions to stabilize the friction coefficient. The polyamide-imide resin can firmly fix the fibers of the friction material, and is excellent in adhesiveness with the core plate and heat resistance. By the synergistic effect of such effects, a facing friction material having excellent friction performance and abrasion resistance and excellent μ-V characteristics is realized.

[0033]

EXAMPLES The present invention will be described more specifically with reference to Examples and Comparative Examples below.

Examples 1 and 2 An iron plate (thickness: 1.8 mm) was used, with an inner diameter of 50 mm and an outer diameter of 80 mm.
It was cut into a ring shape. After coating the coating solution having the composition shown in Table 1 on the surface of the core plate by a roller method to a thickness of about 1 mm, the temperature was raised to 300 ° C. in 30 minutes, and the temperature was kept for 30 minutes to perform baking. After solidification, the surface was polished to form a friction layer having a thickness of 500 μm.

The carbon fiber has a fiber diameter of 6 to 10 μm and a fiber length of 50 to 100 μm, the alumina fiber has a fiber diameter of 2 to 5 μm and a fiber length of 50 to 150 μm, and the aramid fiber has a fiber diameter. A fiber having a diameter of 100 to 150 μm and a fiber length of 5 to 20 mm was used.

Using the facing friction material thus obtained, the amount of wear (500 minutes or 1 minute with a disc material of S45C steel as a mating material)
The amount of wear when a sliding test was performed at a speed of 5,000 minutes and 50 RPM) and the μ-V characteristics (relationship between the sliding speed and the friction coefficient measured by a SAE type tester) were examined, and the results are shown in Table 1.

Comparative Example 1 With respect to a conventional paper-based facing friction material (paper-based friction material thickness 500 μm), the wear amount and μ-V characteristics were examined in the same manner as above, and the results are shown in Table 1.

[0038]

[Table 1]

From Table 1, it is clear that the facing friction material of the present invention has excellent wear resistance and good μ-V characteristics.

[0040]

As described above in detail, according to the facing friction material and the method for producing the same of the present invention, the adhesion between the base material core plate and the friction layer is good and there is no problem of peeling. It has excellent wear resistance. Excellent in μ-V characteristics. Excellent heat resistance and durability. The friction coefficient does not change over time and is stable over a long period of time. A facing friction material having excellent characteristics such as the above is provided.

Continuation of the front page (51) Int.Cl. ⁶ Identification code Office reference number FI Technical display area C09K 3/14 520 C09K 3/14 520E 530 530H

Claims (2)

[Claims] 1. A facing friction material in which a friction layer containing a friction material and an organic binder made of a polyamide-imide resin is formed on the surface of a metal core plate, wherein the friction material is carbon fiber, alumina fiber or aramid. A facing friction material comprising fibers, wherein the content of the friction material in the friction layer is 30 to 60% by weight, and the content of the polyamide-imide resin is 40 to 70% by weight. 2. The method for producing a facing friction material according to claim 1, wherein carbon fiber, alumina fiber and aramid fiber are mixed with a polyamideimide resin to prepare a coating liquid, and the coating liquid is a metal. A method for producing a facing friction material, characterized by applying to a core plate.