JPS62106980A - Asbestosfree friction material for braking - Google Patents

Abstract

PURPOSE:To provide an asbestosfree friction material for braking with low thermal conductivity, by incorporating a mixture of metallic fiber and/or metallic powder and aramid fiber and/or aramid pulp, with a lubricant, binder, filler, etc. CONSTITUTION:Metallic fiber and/or metallic powder (e.g., steel fiber or copper powder) and aramid fiber and/or aramid pulp are mixed in a wt. ratio of 100:5-30. Then, 100-25wt% said mixture, 5-20wt% lubricant such as graphite or molybdenum disulfide, and the balance of binder (e.g., phenolic resin) and filler (e.g., barium sulfate) are mixed and molded to give the intended friction material. Because of low thermal conductivity, the resulting friction material is unnecessary to take particular countermeasures of a rise in temp. of brake fluid, such as a two-layer structure of friction pad, and provides low variation in effectiveness with temp. change.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to an asbestos-free friction material, specifically to an asbestos-free friction material with low thermal conductivity and excellent temperature characteristics of friction coefficient and noise resistance. It is something.

(Prior Art) Semi-metallic friction materials containing steel fibers as a fiber component are often used as asbestos-free friction materials for use in brakes for automobiles and the like.

[Problems to be solved by the invention]

This semi-metallic friction material is mainly composed of steel fibers and graphite, with a binder such as phenolic resin and fillers such as iron powder and barium sulfate, but friction materials made of semi-metallic material alone have high thermal conductivity. Therefore, a two-layer material structure using asbestos is required as a measure against brake fluid temperature.

Also, since steel fiber and graphite are used in multiple digits, 2
There was a drawback that the coefficient of friction at low temperatures such as 0 to 50'C was low.

(Means and effects for solving the problems) The present invention was made to eliminate the above-mentioned drawbacks of conventional semi-metallic friction materials. A friction material comprising aramid pulp and aramid pulp in a ratio of 100:5 to 30 in a total amount of 10 to 25% by weight, 5 to 20% by weight of a lubricant such as graphite or molybdenum disulfide, and the remainder a binder and filler. The main point is the material.

[Effect]

According to the present invention, the optimum mixing ratio of metal fibers and/or metal powder and aramid fibers and/or aramid pulp (100:5 to 30) is set, and the total amount thereof is 10 to 25% by weight in the friction material formulation. This makes it possible to use 5 to 20% by weight of a lubricant such as graphite, and as a result, low thermal conductivity is achieved, eliminating the need for special brake fluid temperature measures, and improving the temperature characteristics of the friction coefficient. Furthermore, noise resistance can also be improved by incorporating a fluorine-based organic substance.

The metal fibers and/or metal powder in the abrasive material of the present invention include fibers and particles of steel, copper, brass, stainless steel, and the like. The binder may be a phenol resin, and the filler may be an inorganic material such as barium sulfate, calcium carbonate, antimony sulfide, or the like, or an organic material such as rubber powder or cashew powder, which is generally used in friction materials.

[Example] The compositions of the conventional semi-metallic friction material (conventional product) and the friction material of the present invention (inventive product) shown in Table 1 were thoroughly stirred and mixed and weighed. The product was placed in a mold and molded under heat and pressure to obtain each product.

(Effects of the Invention) Each of the conventional products and the product of the present invention has a 50”
The temperature of the back metal when heated to C was measured, and the results shown in Table 2 were obtained.

A fade test was conducted to measure the maximum brake fluid temperature, backing metal temperature, and time to reach the maximum temperature, and the results shown in Table 3 were obtained.

A temperature-specific efficacy test was conducted using a meter, and the results shown in FIG. 1 were obtained.

As is clear from this, the product of the present invention has achieved lower thermal conductivity than the conventional product, and it is clear that there is no need to take special brake fluid temperature measures such as a two-layer material.

It was also observed that the effect change at each temperature was small, and the temperature characteristics of the friction coefficient were improved.

[Brief explanation of drawings]

FIG. 1 is a chart showing the results of temperature effectiveness tests for conventional products and products of the present invention. 1 False ('C) Spontaneous writing of procedural amendment) September 8, 1986

Claims (1)

[Claims] (1) Metal fiber and/or metal powder and aramid fiber and/or aramid pulp in a ratio of 100:5 to 30
A friction material characterized in that the total amount of both is 10 to 25% by weight, 5 to 20% by weight of a lubricant such as graphite or molybdenum disulfide, and the balance is a binder and a filler.