JPH02300531A - Non-asbestos group friction material - Google Patents

Abstract

PURPOSE:To provide a stable frictional function and an excellent fade function so as to reduce the rotor attack in order to prevent a rotor from being eccentrically worn, by adding a minimum but necessary volume of iron group fibers, iron group particles or iron group powder in at least a part of a fiber component. CONSTITUTION:In a frictional material containing therein a fiber component other than asbestos, a thermo-hardenable resin component such as phenol resin or the like, graphite, and a filler powder such as barium sulfate or the like, a minimum but necessary volume of iron group fibers, iron group particles or iron group powder is added in at least a part of the fiber component. Thus, with the use of a minimum but necessary volume of the iron group fibers, unlike a semimetallic frictional material or the like using a large volume thereof, the instant friction material may have a stable frictional function and a satisfactory fade function, and further, it may have a strength which is held at a satisfactory level. Moreover, it is possible to obtain a non-asbestos group frictional member having a small rotor attack.

Description

Detailed Description of the Invention [Industrial Field of Application] The present invention is a friction material used as automobile brake panes, brake linings, clutch facings, etc., which does not contain asbestos as a fiber component and has high-speed performance. This invention relates to a non-asbestos friction material that has good fade resistance, maintains a good level of strength, and has low rotor attack properties.

[Conventional technology]

Conventionally, automobile brake pads, brake linings,
Asbestos is often used as a base material for friction materials used in clutch facings, etc., but as it has been pointed out that asbestos dust is harmful to the human body, its use is being regulated, and asbestos There is a growing demand for friction materials that do not require the use of friction materials.

Therefore, as a non-asbestos friction material that does not use camphor, we use metals and fibers mainly made of glass fiber and iron fiber.

Various proposals have been made regarding semi-metallic friction materials using heat-resistant organic fibers and friction materials whose fiber base material does not contain any iron fibers.

[Problem to be solved by the invention]

However, friction materials using the above-mentioned iron-based fibers generally have high thermal conductivity, good effectiveness at high speeds and fade resistance, and are also excellent in strength.

Not only is it heavy and has the problem of igniting at high temperatures, but it also comes into contact with vibrations when in contact with a mating material such as a disc rotor, and even when it is not in contact, attacking and damaging the mating material. In addition, the temperature of the adhesive layer that bonds the friction material layer and backing metal layer increases, causing the adhesive to decompose and causing the friction material and backing metal to separate, creating a dangerous situation. There is also the problem that there is a risk of inviting

If the rotor is aggressive when idling or braking.

As mentioned above, there is a risk that the rotor may be unevenly ground and wear unevenly, and if this uneven wear is sufficient, it will cause unpleasant vibrations not only in the brake pedal but also in the vehicle body during braking.

On the other hand, non-asbestos friction materials that do not contain iron-based fibers with high thermal conductivity as fiber base materials have low rotor attack properties and are good. When the sliding surface becomes hot, it becomes difficult for heat to dissipate through the friction material, resulting in a problem of reduced effectiveness at high speeds.

Therefore, the problem to be solved by the present invention is to develop a friction material that is non-asbestos and free from the above-mentioned problems.

[Means to solve the problem]

The present invention was made with the aim of solving the above-mentioned problems, and consists of a fiber component excluding asbestos, a thermosetting resin component such as phenol resin, and a filler powder component such as graphite and barium sulfate. The friction material is characterized in that at least a portion of the fiber component contains a necessary minimum amount of iron-based fibers, iron-based grains, or iron-based powder.

That is, the inventor of the present invention conducted research with the aim of obtaining a non-asbestos friction material that has stable friction performance and good fade performance, maintains strength at a good level, and has low rotor attack properties. As a result of repeated research, they realized that the above object could be achieved by using a small amount of iron-based fibers in the required amount without using large amounts as in semi-metallic friction materials, and thus accomplished the present invention.

In the present invention, the non-iron-based fiber components used include organic fibers such as aramid fibers, inorganic fibers such as potassium titanate, glass fibers, and ceramic fibers.
Examples include nonferrous metal fibers such as brass fibers, but when inorganic fibers such as aramid fibers and potassium titanate are used in combination, a friction material with a good balance of performance can be obtained without impairing the desired effect.

Examples of the binder include thermosetting resins such as phenol resins, urea resins, melamine resins, and modified resins thereof, and heat-resistant resins such as polyacetals, aromatic polyimide resins, and fluororesins.

Additionally, graphite is used as a friction modifier and filler.

There are metal powders other than iron, molybdenum disulfide, lubricating substances such as cashew dust, barium sulfate, calcium carbonate, etc., and zircon sand.

Materials with relatively high Mohs hardness, such as alumina, can also be used as fillers.

Note: 1. Iron-based fibers and iron-based powders used in the present invention.

The amount of iron-based powder is preferably about 1 to 5% by weight based on the total amount of the friction material. This is because if the amount is less than that, the strength will decrease, and if it is more than that, the rotor aggressiveness will increase.

[Action of the invention]

The friction material of the present invention is a non-asbestos friction material, and contains a small amount of iron-based fiber, iron-based powder, and iron-based powder, that is, 1 to 5% by weight of the total amount of the friction material.
As a result, stable friction performance and excellent fade performance are achieved without causing the problems caused by the low thermal conductivity of conventional non-asbestos friction materials that do not contain iron fibers as fiber base materials. As a result, the rotor aggressiveness becomes smaller.
There is no risk of uneven wear of the rotor.

〔Example〕

Next, examples of the present invention will be described.

Examples r and n were prepared by using aramid fiber, potassium titanate, and a small amount of steel fiber as the fiber base material, using phenol resin as the binder, and using iron powder, graphite, barium sulfate, and other materials as the filler. , m and Comparative Example I,
After making I'I friction materials and investigating their performance,
It was as shown in the table below.

◎...Excellent, O...Good, △...Slightly good, ×...Poor [Effects of the invention] As described above, the present invention is a non-asbestos-based fiber containing a small amount of iron-based fiber as a fiber base material. As shown in the examples, the friction material has stable friction performance and good fade performance by adding organic fibers such as aramid fibers and potassium titanate, and small amounts of iron fibers and iron powder particles. In addition, the rotor aggressiveness is small, so the rotor does not grind or wear unevenly, the effectiveness at high speeds is good, and the strength can be maintained at a good level.

Therefore, it is suitable as a friction material for use in automobile brake pads, brake linings, clutch facings, etc.

Claims (1)

[Scope of Claims] 1. In a friction material containing a fiber component excluding asbestos, a thermosetting resin component such as a phenol resin, and a filler powder component such as graphite or barium sulfate, at least a portion of the fiber component A non-asbestos friction material characterized by containing iron-based fibers, iron-based grains, or iron-based powder. 2. The non-asbestos friction material according to claim 1, wherein the amount of iron-based fibers, iron-based particles, or iron-based powder is 1 to 5% by weight based on the total amount of the friction material. 3. The fiber component according to claim 1 or 2, wherein the fiber components other than asbestos are organic fibers such as aramid fibers, inorganic fibers such as potassium titanate, glass fibers, and ceramic fibers, and metal fibers such as brass fibers. Non-asbestos friction material.