JP2879364B2 - Non-asbestos friction material - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a friction material used as a brake pad, a brake lining, a clutch facing and the like of an automobile, which does not contain asbestos as a fiber component, and has a squealing performance. The present invention relates to a non-asbestos-based friction material having excellent abrasion resistance at high temperatures and good friction performance.

[Conventional technology]

Conventionally, asbestos has been widely used as a base material for friction materials used for automobile brake pads, brake linings, clutch facings, etc. As a result of the finding that asbestos dust is harmful to the human body, Its use is being regulated, and there is an increasing 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, and metal fibers as fiber components and use thermosetting materials such as phenolic resins as binders. The resin is made of graphite, barium sulfate, alumina or the like as a filler powder component.

[Problems to be solved by the invention]

However, in a friction material using a thermosetting resin such as the above-mentioned phenol resin as a binder, the resin melts or decomposes at a high temperature to generate gas, which causes a fade phenomenon and an unstable friction coefficient. There is a problem.

At present, in order to solve this problem, the resin component is suppressed to a small amount of 15 to 25% by volume of the total amount of the friction material. However, when the amount of the organic binder is reduced, the strength and wear resistance of the friction material are reduced. Sexual decline could not be avoided. That is, in the non-asbestos-based friction material, unless the amount of the binder is larger than that of the asbestos-based friction material, sufficient strength and wear resistance as the friction material cannot be obtained.

Therefore, it was conceived that iron-based fibers were included in the fiber component, but friction materials using iron-based fibers generally have high thermal conductivity and are excellent in wear resistance and fade resistance at high temperatures. However, not only is there a problem of heavy weight or ignition at high temperatures, but also there is a drawback that the aggressiveness to a counterpart material such as a disk rotor is large.

Therefore, the problem to be solved by the present invention is to provide a friction material which has low face-to-face aggression, exhibits stable friction performance from low to high temperatures, and has excellent squealing performance. is there.

[Means for solving the problem]

The present invention has been made for the purpose of solving the above-mentioned problems, and its composition is a fiber component other than asbestos, a thermosetting resin component such as a phenol resin, and a filler powder component such as graphite and barium sulfate. And a potassium titanate fiber having a fiber length of 0.1 to 3 mm and a fiber diameter of 10 to 60 μm (hereinafter referred to as potassium titanate fiber A) and a fiber length of 10 to 30 μm and a fiber diameter of 0.2 to 0.5. It is characterized by containing a potassium titanate fiber of μm (hereinafter referred to as potassium titanate fiber B).

That is, the inventor of the present invention showed stable friction performance from low to high temperatures, and as a result of repeatedly conducting research for the purpose of obtaining a non-asbestos-based friction material having excellent squealing performance and abrasion resistance at high temperatures, a fiber was obtained. The inventors have found that the above object can be achieved by including at least a part of two kinds of potassium titanate fibers having different shapes in at least a part of the components, thereby accomplishing the present invention.

The total content of the potassium titanate fiber in the above is preferably 5 to 30% by volume based on the total amount of the friction material.
% Or less, the stability of the friction coefficient is poor, and if it is 30% or more, the specific surface area of the fiber becomes large. Therefore, unless the amount of the binder such as phenolic resin is increased, the strength cannot be secured and the performance may be deteriorated.

In the present invention, those used as fiber components other than potassium titanate fiber include organic fibers such as aramid fiber, inorganic fibers such as glass fiber, rock wool and ceramic fiber, copper, bronze, aluminum, and the like. Examples of the binder include metal fibers such as brass, and examples of the binder include a thermosetting resin such as a phenol resin, a urea resin, a melamine resin, or a denatured resin thereof; And a filler having lubricating action such as graphite, metal powder, molybdenum disulfide and cashew dust, and barium sulfate and calcium carbonate.

[Function of the invention]

The friction material of the present invention is a non-asbestos friction material. By using two types of potassium titanate fibers having different shapes for at least a part of the fiber component, the face-to-face aggressiveness is small and stable friction performance from low to high temperatures is obtained. In addition, the squeal performance is improved.

〔Example〕

 Next, examples of the present invention will be described.

Phenol resin as binder, graphite as filler,
Aramid fiber, rock wool, metallic fiber, potassium titanate A
And B were mixed uniformly at room temperature under a pressure of 40
After preforming at 0 kg / cm ² , temperature 150 ° C, pressure 400 kg / cm ²
For 10 minutes, followed by heat treatment at 180 ° C. for 5 hours to obtain the friction materials of Examples I and II shown in Table 1. The numerical values in the table represent% by volume.

In the composition of the above example, one kind of potassium titanate fiber was used, and Comparative Examples I and II were similarly obtained.

Table 2 shows the results of a test of these friction materials according to the friction performance test method specified in JASO "Test Method for Dynamometer of Passenger Car Brake System" and the results of a squeal test performed on an actual vehicle.

[Effect of the Invention] As described above, the non-asbestos-based friction material of the present invention which does not contain asbestos as a fiber base material includes, as shown in Examples, organic fibers such as aramid fibers, inorganic fibers such as rock wool, and copper. It comprises a metal fiber such as fiber, a binder such as phenolic resin, and a filler component such as graphite and barium sulfate. At least a part of the fiber component contains two kinds of potassium titanate fibers having different shapes in a specific amount. As a result, stable friction performance from low to high temperatures is exhibited, and squealing performance and wear characteristics at high temperatures are improved as described above. Therefore, it is suitable as a friction material used for automobile brake pads, brake linings, clutch facings, and the like. .

────────────────────────────────────────────────── ─── Continuation of the front page (56) References JP-A-63-62926 (JP, A) JP-A-59-80543 (JP, A) (58) Fields investigated (Int. Cl. ⁶ , DB name) C09K 3/14 F16D 69/02 WPI / L (QUESTEL)

Claims (3)

(57) [Claims] 1. A friction material containing a fiber component other than asbestos, a thermosetting resin component such as a phenol resin, and a filler powder component such as graphite and barium sulfate, wherein at least a part of the fiber component has a shape. Of two types of potassium titanate fibers, one of which has a fiber length of 0.1 to 3 mm and a fiber diameter of 10 to 60 μm, and the other has a fiber length of 10 to 30
A non-asbestos-based friction material characterized by having a fiber diameter of 0.2 to 0.5 μm. 2. The non-asbestos-based friction material according to claim 1, wherein the amount of each potassium titanate fiber is 0.5 to 20% by volume relative to the total amount of the friction material, and the total amount is 5 to 30% by volume. Wood. 3. The fiber component other than asbestos is an organic fiber such as aramid fiber, an inorganic fiber such as glass fiber, rock wool and ceramic fiber, and a metal fiber such as copper, bronze, aluminum and brass. Item 2. The non-asbestos-based friction material according to Item 1.