JP3420596B2 - Non-asbestos friction material - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a friction material used as an automobile brake pad, brake lining, clutch facing, etc., which has a moderately high coefficient of friction and is stable and has good face-to-face aggression. The present invention relates to a non-asbestos-based friction material having a small amount.

[0002]

2. Description of the Related Art Conventionally, asbestos is often used as a base material for friction materials used for automobile brake pads, brake linings, clutch facings, etc. However, asbestos is harmful to humans due to its dust. As a result of being pointed out, its use is being regulated, and there is a strong demand for friction materials that do not use asbestos. Therefore, many proposals have been made for non-asbestos-based friction materials that do not use asbestos, but most of them use heat-resistant organic fibers, glass fibers, metal fibers, etc. as the fiber component and thermosetting phenolic resin, etc. as the binder. In this embodiment, a conductive resin is used as a filler component such as a lubricant such as graphite or molybdenum disulfide, or an abrasive such as alumina or zirconium silicate.

[0003]

Materials having high hardness, such as alumina, quartz, and zirconium silicate, which are generally used as a part of the filler component, have a high friction coefficient as an abrasive to enhance the braking effect. Is used for.

However, since the above-mentioned materials having a high effect of increasing the braking effect have a high Mohs hardness, they have great aggression to the disc rotor or the like which is a mating material, and an unpleasant sound called squeal is generated during braking. It may cause to cause the use amount must be suppressed.
In addition, when the mating material has streaks on the mating material, it may be difficult to obtain a stable friction coefficient during the subsequent brake control. For this reason, it is technically difficult to provide a friction material that has a moderately high friction coefficient and is stable without impairing the face-to-face aggression, and has less squeaking.

Therefore, the problem to be solved by the present invention is to focus on the frictional force between the mating material such as the disc rotor and the friction material such as the disc pad in the above non-asbestos friction material, and to obtain good face-to-face aggression and It is an object of the present invention to provide a non-asbestos-based friction material that satisfies both of a reasonably high and stable friction coefficient and has less squeaking.

[0006]

SUMMARY OF THE INVENTION The present invention has been made for the purpose of solving the above-mentioned problems, and its constitution is a fiber component other than asbestos, a curable resin component such as phenol resin, graphite and sulfuric acid. A friction material containing a filler component such as barium contains feldspar powder in at least a part of the filler component.

The face-to-face aggression is often evaluated by the amount of wear of the mating material after the test, the state of surface irregularities, and how marks are made, but the amount of wear is small and the mating material is evenly ground. Is desirable. For example, even if the amount of wear is small, it is difficult to obtain a stable friction coefficient during braking by braking even if the amount of wear is small or if there are large scratches. In such a state, a large frictional force is applied only to the friction material and a part of the mating material, and the abrasive material with high hardness such as alumina in the friction material scrapes off a part of the mating material, or the grinding material is removed from the friction material. It is conceivable that it slipped out and was sandwiched between the friction material and the mating material, and both sides were scraped off.

Also, the brake squeal tends to be adversely affected by the use of a large amount of hard abrasive. This is considered to be because the cause of squeal is mainly frictional vibration during braking, and the use of a hard abrasive material applies an uneven force between the friction material and the mating material. However, fillers such as alumina, quartz, and zirconium silicate are generally added as abrasives in order to improve the braking effect, and are essential as materials for automobile brake pads and the like.

Therefore, the inventor of the present invention has earnestly studied for the purpose of obtaining a non-asbestos-based friction material having a moderately high coefficient of friction and stability, good face-to-face aggression, and less squeaking during braking. As a result of stacking, it was found that the above object can be achieved by including feldspar powder in at least a part of the filler component, and the present invention has been accomplished. That is, feldspar is a material with high hardness like alumina, quartz, etc. However, if a certain amount of force is applied, the cleavability of the feldspar causes crystal collapse and peeling, so a large force is partially applied to the friction surface. In this case, a uniform frictional force is easily exerted, the surface of the rotor or the like, which is a mating member, is not largely scraped off, frictional vibrations are less likely to occur, and therefore squeal is less likely to occur.

[0010] feldspar Ca, Na, albite NaA1Si ₃ O ₈ in aluminosilicate minerals consisting of K, etc., anorthite Ca
It is produced as a solid solution of A1 ₂ Si ₂ O ₈ and gangue KA1Si ₃ O ₈ . Also, those mainly composed of albite and anorthite are called plagioclase, and those mainly composed of albite and orthoclase are called alkali feldspar.

Concerning the constituents of the friction material of the present invention, conventional ones can be used except that feldspar powder is used, and examples of the constituents used as the fiber component include organic fibers such as aramid fibers, glass fibers, rock wool, Inorganic fibers such as ceramics fibers and potassium titanate fibers, and metal fibers such as copper, bronze, aluminum and brass are mentioned.
Thermosetting resin or polyacetal such as phenol resin, urea resin, melamine resin, or modified resin thereof,
Heat-resistant resins such as aromatic polyimide resins and fluororesins can be mentioned, and fillers such as graphite, metal powder, molybdenum disulfide and cashew dust, which have a lubricating effect, ceramics, zirconium silicate, etc. Examples include various abrasives, barium sulfate, and calcium carbonate.

[0012]

The friction material of the present invention is a non-asbestos friction material, and since at least a part of the filler component contains feldspar powder having a cleavage property, the friction coefficient is reasonably high and stable, and the face-to-face aggression property is also high. Is good and there is little squeaking.

[0013]

EXAMPLES Next, examples of the present invention will be described. Using aramid fiber, rock wool, copper fiber as the fiber base material, phenol resin as the binder, and alkali feldspar powder with an average particle size of about 10 μm as the filler component, graphite, barium sulfate, alumina, and zirconium silicate. , Evenly mix them with a stirrer, room temperature, pressure 400 kg /
After preforming with cm ² , the temperature is 160 ℃ and the pressure is 400kg /
Heat press molding at cm ² for 8 minutes, then at a temperature of 180 ℃ 5
After heat treatment for a period of time, friction materials of Examples A and B having the compositions shown in Table 1 were obtained.

Further, the friction materials of Comparative Examples a to c which did not use feldspar powder were obtained in the same manner. In addition, the numerical value in a table shows volume%. The friction materials of Examples A and B and Comparative Examples a to c produced by the above method were subjected to a friction and wear test by a full size dynamo test (JASO, C406 compliant, inertia 5 kgm).
s ² ) and the results of a squeal test using an actual vehicle are shown in Table 2.

[0015]

As described above, the non-asbestos-based friction material of the present invention which does not contain asbestos as a fiber base material includes organic fibers such as aramid fibers, inorganic fibers such as rock wool, metal fibers such as copper fibers,
It is composed of a binder such as phenolic resin and a filler component such as graphite and barium sulfate. As a result of including feldspar powder in at least a part of the filler component, the friction coefficient is reasonably high and stable as described above, and It is suitable as a friction material used for automobile brake pads, brake linings, clutch facings, etc. because it has good face-to-face attack and less squeaking.

[Table 1]

[Table 2]

─────────────────────────────────────────────────── ─── Continuation of the front page (58) Fields investigated (Int.Cl. ⁷ , DB name) C09K 3/14 C08J 5/00-5/10 F16D 69/00-69/02

Claims (3)

(57) [Claims] 1. A non-asbestos friction material containing a fiber component other than asbestos, a thermosetting resin component, and a filler component, wherein at least a part of the filler component contains feldspar powder. System friction material. 2. The non-asbestos friction material according to claim 1, wherein the content of the feldspar powder is 0.1 to 20% by volume with respect to the total amount of the friction material. 3. The non-asbestos-based friction material according to claim 1, wherein the fiber component other than asbestos is an organic fiber, an inorganic fiber, or a metal fiber.