JPH0723463B2 - Friction material - Google Patents

Description

TECHNICAL FIELD The present invention relates to a friction material, and particularly to a friction material having excellent fade resistance and suitable for a brake pad for an automobile.

<< Prior Art >> Conventionally, a brake pad for an automobile has a friction material in which a metal fiber, glass fiber, ceramic fiber or the like is used as a base material, and a filler and a binder are mixed with the base material.
Phenolic resin is used as the binder.

<Problems to be Solved by the Invention> However, in the conventional friction material as described above, since a phenol resin is used as a binder, when heat resistance is taken into consideration, a reactive group may be formed between straight or phenol groups. It is necessary to have benzene nuclei that do not have as a main component, and in this case, since the crosslink density is high and the matrix is solid, the hardness is high and the fade resistance is lowered.

Further, a modified resin such as cashew, oil or rubber can be used as the binder, but in this case, there is a problem in that it is excellent in flexibility but inferior in heat resistance.

On the other hand, in order to improve the fade resistance, it is possible to reduce the amount of resin compounded and increase the total amount of filler, but this method causes increased wear of the brake pad and
There was a problem that the braking effectiveness decreased and noise was generated.

The present invention has been made in view of the conventional problems as described above, and an object thereof is to use a copolymer resin of p-phenylphenol and phenol having excellent heat resistance as a binder, And to provide a friction material having excellent fade resistance.

<Means for Solving the Problems> In order to achieve the above object, the present invention uses a heat-resistant resin as a binder and a reinforcing fiber as a base material, and is made of graphite, gold, barium sulfate,
In the friction material using calcium hydroxide as a filler, the heat resistant resin is a copolymer resin of p-phenylphenol and phenol.

<< Operation >> In the present invention, since the p-phenylphenol resin having excellent heat resistance is used as the binder, the friction coefficient is stable under high temperature and high load.

<< Examples >> Examples of the present invention will be shown below, but these are examples.
The present invention is not limited thereby.

First, the binder resin of p-phenylphenol and phenol is a copolymer of p-phenylphenol and phenol at a molar ratio of 1: 1 using ammonia as an alkali catalyst and undergoing a copolymerization reaction with formaldehyde to condense. Can be obtained at.

Next, using this resin as a binder, steel fibers of the base material and graphite and other fillers are compounded according to the volume ratio (%) shown in the following table, and this is uniformly kneaded.

Next, the above-mentioned composite material is filled in a mold, and the temperature is 150 ° C and the pressure is 5
It is compression molded at 00Kg / cm ² .

The formed product was subjected to aftercare at 200 ° C for 4 hours under predetermined conditions.

FIG. 1 is a comparison diagram of a fade test when the friction material obtained as described above and the friction material of the conventional example are used for a brake pad for an automobile. A is the friction material obtained by this embodiment, and B is the friction material. Indicates the friction coefficient of the conventional friction material with respect to the number of times of braking.

As shown in the figure, in this example, since a copolymer resin of p-phenylphenol and phenol having excellent heat resistance was used as the binder, when only a general phenol resin was used as the binder as in the conventional case. The friction coefficient is higher than
It can be seen that a stable brake pad for automobiles having excellent fade resistance can be obtained.

Although the copolymer resin of p-phenylphenol and phenol was synthesized using alcal as a catalyst in this example, it may be synthesized using an acid as a catalyst.

Further, as the reinforcing fiber, in addition to steel fiber, metal fiber such as aluminum fiber, copper fiber, brass fiber, zinc fiber, nickel fiber, chrome fiber and the like can be used.

Further, inorganic fibers such as glass fibers and ceramic fibers can also be used as the reinforcing fibers.

Furthermore, organic fibers such as aramid fibers and acrylic fibers can also be used as reinforcing fibers.

<< Effects of the Invention >> As described above, the friction material according to the present invention comprises a heat-resistant resin as a binder, a reinforcing fiber as a base material, and graphite, metal powder, barium sulfate, calcium hydroxide, or the like as a filler. In the above, since the heat resistant resin is a copolymer resin of p-phenylphenol and phenol, a friction material having excellent heat resistance and fade resistance can be obtained.

[Brief description of drawings]

FIG. 1 is an explanatory diagram of the friction coefficient with respect to the number of braking times of the friction material obtained in this example and the friction material in the conventional example. A: Friction coefficient characteristic diagram of friction material obtained in this example B: Friction coefficient characteristic chart of friction material in conventional example

Claims (6)

[Claims] 1. A friction material comprising a heat-resistant resin as a binder and a reinforcing fiber as a base material and graphite, metal powder, barium sulfate, calcium hydroxide or the like as a filler, wherein the heat-resistant resin is p-phenylphenol. A friction material, which is a copolymer resin of phenol. 2. The friction material according to claim 1, wherein the copolymer resin of p-phenylphenol and phenol is synthesized by using an acid as a catalyst. 3. The friction material according to claim 1, wherein a copolymer resin of p-phenylphenol and phenol is synthesized by using an alkali as a catalyst. 4. The friction material according to claim 1, wherein the reinforcing fibers are metal fibers such as steel fibers, aluminum fibers, copper fibers, brass fibers, zinc fibers, nickel fibers, and chromium fibers. 5. The friction material according to claim 1, wherein the reinforcing fibers are inorganic fibers such as glass fibers and ceramic fibers. 6. The friction material according to claim 1, wherein the reinforcing fibers are organic fibers such as aramid fibers and acrylic fibers.