KR920001910B1 - Friction material - Google Patents

Abstract

The method for producing a friction material is characterized by defiberizing 10-45 % kraft pulp and 5-15 % linter pulp in the beater to be 400-500 freeness, adding an coagulating agent to the mixed slurry of the pulps, 5-30 % diatom earth, 1-15 % silica, 1- 15 % zeolite, 10-45 % cashew nut shell oil and 1-10 % cardolite, molding the mixt. under the condition of 30 dg/cm2 surface pressure and 50-60 deg.C temp., blanking it to be a fixed size, and heat-hardening it. The friction material for brakes and clutches has a good porosity and durability.

Description

Method for producing a wet friction material.

1 is a graph showing the coefficient of friction of the present invention (Example 1) and the conventional product according to the oil temperature change.

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing a wet friction material having excellent friction characteristics in water as a friction material used in wet brakes and clutch systems of automobiles, motorcycles, heavy equipment, and the like.

Generally, wet friction materials contain inorganic fillers, thermosetting resins and the like based on pulp, and the physical properties of the friction materials vary depending on the type of inorganic filler and thermosetting resin.

Conventional wet friction materials are prepared by mixing inorganic fillers such as silicates, metal oxides, alumina, and pulmonary resins with phenolic resins.They have low porosity and low heat resistance. There was a flaw.

That is, the wet friction material improves the flow phenomenon of the lubricating oil at the contacting area, thereby reducing the rise of the lubricating oil temperature due to the frictional heat, preventing the soaking of the friction material and maintaining a stable friction characteristic according to the temperature of the cotton. And thus durability is required.

Therefore, the present invention is to solve the drawbacks of the conventional wet friction material (Patent Publication No. 83-2041) mentioned above, and as an inorganic filler, it is more mechanical than silica compounds such as silica, diatomaceous earth and zeolite and conventional phenolic resin. Phenol-cashew shell oil-based thermosetting resins with excellent properties are used. Especially, in order to improve friction characteristics, cardolite is added and the pulp, which is a basic material, is also used as a conventional cellulose. It is a method of manufacturing a wet friction agent by reinforcing-mixing a linter pulp to a system kraft pulp.

The wet friction material manufactured as described above has excellent porosity and durability, which prevents the deterioration of the friction characteristics due to the increase in oil temperature and maintains a constant coefficient of friction even at high temperatures.

In more detail, the manufacturing method of the present invention, after decomposing graft pulp and linter pulp in a pulp beater to Yeosu 400-500, a certain amount of silica, diatomaceous earth Inorganic fillers, such as zeolite and cardorite, and thermosetting resins used to increase mechanical strength. A small amount of pulp mixture slurry is uniformly mixed with a water-soluble or oil-soluble phenol-cashew nut shell oil-based modified resin. The wet friction material of the present invention is manufactured by dehydration and hot press molding under a condition of a surface pressure of 30 kg / cm 2 and a temperature of 50 to 60 ° C., transferred to a mold of a hot forming press to which a water vacuum system including an aggregate is added.

Example 1

Friction material composition

Graft Pulp 25% Silica 5%

Linter pulp 10% zeolite 10%

Thermoset 30% Cardorite 5%

Diatomaceous Earth 15%

After kraft and linter pulp is kneaded to 400-500 in the pulp beaker so that the friction material composition is as described above, a small amount of flocculant is added to the pulp mixing sludge which is uniformly mixed with silica, diatomaceous earth, zeolite, cardorite and thermosetting resin. After molding under a surface pressure of 30kg / ㎠, a temperature of 55 ℃ in the mold and punched to the dimension 0.4 ~ 1mm and attached to the iron plate under heating pressure and then hardened for a predetermined time (1 ~ 2hr) to prepare the wet friction material of the present invention. .

Comparing the physical properties (impregnated porosity, heat resistance, friction characteristics) between the present invention and the conventional product thus produced are shown in Tables 1, 2 and 1 below.

Example 2

The physical properties of the prepared friction agent were similar to those of Example 1, except that the amount of diatomaceous earth was 5% and the amount of zeolite was 20%.

Example 3

The frictional agent physical properties of Example 1 were similar to those of Example 1, except that silica was not used and the amount of cardorite was 10%.

Example 4

The physical properties of the prepared marmalane material was similar to that of Example 1 except that the zeolite was 5% and the cardorite was 10%.

1. Impregnation rate

The invention (Example 1) and the comparative product were cut to predetermined dimensions, and after 15 hours of incorporation under an oil temperature of 80 ° C., measured as a weight change, and the results were shown in Table 1.

TABLE 1

2. Heat resistance

The invention (Example 1) and the comparative product was measured by the thermogravimetric analysis (TGA) while increasing the temperature in the nitrogen atmosphere by 1 ℃ per minute while reducing the weight according to the temperature, the results are shown in Table 2.

TABLE 2

3. Friction Characteristics

In order to investigate the friction characteristics of the invention (Example 1) and the comparative product, a wet friction tester (cygnus (II) should be used to use SAE # 90 gear oil under the pressure of 10kgf / cm2 and sliding speed of 5m / sec according to JISD4311). As a result of measuring the friction coefficient according to the change of Yumon (50 ~ 150 ℃), it was as shown in FIG.

As can be seen from the above-described comparative tests of the impregnated porosity, heat resistance and friction properties, the present invention is much superior to the conventional products.

Claims (1)

10 to 45% of kraft pulp and 5 to 15% of linter pulp are desalted at 400 to 500 in Yeosu Island in the pulp beaker, and then 5 to 30% of diatomaceous earth, 1 to 15% of silica, 1 to 15% of zeolite, and phenol-ashnut A small amount of flocculant is added to the pulp mixture slurry in which 10 to 45% of shell oil-based modified resin and 1 to 10% of cardorite are uniformly mixed, and then molded in a mold under a surface pressure of 30 kg / cm 2 and a temperature of 50 to 60 ° C. A method of manufacturing a wet friction material, characterized in that by heating and curing by attaching it to an iron plate under heat and pressure.

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