JPS6152434A - Friction material - Google Patents

Abstract

PURPOSE:To provide a friction material excellent in judder characteristic at the time of departure by forming the friction material by 20-30pts. of fiber processed to be bulky, 5-25pts. of binder, 10-30pts. of inorganic filler and 15- 45pts. of the other components. CONSTITUTION:The friction material is formed by 20-30pts. of heat-resisting fiber processed to be bulky, 5-25pts. of binder such as phenol resin or the like, 10-30pts. of inorganic filler such as barium sulfate, mixture of calcium carbonate, or the like, and 15-45pts. of the other components. Thus, judder will not occur at the time of departure in a specified car without damaging general characteristics of a friction material such as coefficient of friction, abrasion, strength and so on.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to improvements in friction materials for vehicles, particularly dry clutch facings and brake linings.

(Prior art) Conventionally, asbestos-free friction materials have been developed as this type of friction materials in order to avoid deterioration of the production environment. Improved products are known, such as those based on fibers or general organic synthetic fibers, or (3) those based on heat-resistant fibers such as glass fibers, phenol fibers, and carbon fibers.

However, the method 1) has disadvantages such as being heavy and causing rust to adhere to the mating material, which may affect the characteristics of the clutch, etc. Type (2) has drawbacks such as poor heat resistance and strength. The material of (3) has poor adhesion with the binder and the desired strength cannot be obtained, but has one drawback.

Therefore, the present inventors invented a friction material based on fibers that have been subjected to bulk processing of at least one or more types selected from the group consisting of glass fiber and carbon fiber, and the friction material is It is publicly known (Japanese Patent Laid-Open No. 56-167934).

This B ring material had excellent strength, friction coefficient, and wear, but
When we evaluated these inoculations, we found that they had the drawback of causing shudder when starting on certain vehicles.

Furthermore, the present inventors investigated compounding agents for rubber binders in order to eliminate the above-mentioned drawbacks, and as a result, they were able to confirm that Nermal Black is effective against shudder. Therefore, the present inventors used the fibers, which have been subjected to bulk processing of at least one or more types selected from the group consisting of glass fibers, phenolic resins, and carbon fibers, as a base material, and added one of the compounding agents to the fibers. As a result, he invented a friction material containing thermal black, and this invention has become publicly known (Japanese Patent Laid-Open No. 58-747).
75>. However, in the subsequent evaluation, "F passenger car, 4
It has been found that when used under severe conditions such as in a wheel-drive passenger car, it has the disadvantage that it tends to slip.

[Problem that the invention seeks to solve]

The present invention overcomes all of the above drawbacks in a well-balanced manner, and generally I! Jv! I that has excellent shudder properties during starting without compromising properties such as abrasion resistance and strength required for the material, and does not cause slippage even under severe conditions.
The purpose is to provide a friction ring material.

[Means for solving problems]

The friction material of the present invention comprises 1 part of 100ffiff, 20 to 3 m of bulky processed fibers made of at least one of a group of heat-resistant fibers such as glass fibers, phenol fibers, and carbon fibers. Serious part and binder 5~
It is characterized by being composed of 25 parts by weight, 10 to 30 parts by weight of an inorganic filler, and 15 to 45 parts by weight of other components including rubber.

m Ili I! which becomes the II rubbing material base material of the present invention! ¥ is
We aim at UVt group materials that are heat resistant at 300°C, specifically glass fibers, phenol fibers, carbon fibers, etc.

What this term heat resistance means is 300'C! !
This means that it is stable to heat without fiber loss or shrinkage phenomena. The fibers used in this I'll material are 1 &!
The fibers may be made of at least one type of fiber group, and may be one type or two or more types of fibers. Usually one type of glass fiber is used. The diameter and length of the fibers are not particularly limited, but it is preferable that the single fibers be 12μ or less, and when used, several hundred single fibers are converged, subjected to necessary fiber processing such as strands, and then further processed to make them bulky. use.

This bulky processing is, as introduced in some literature,
It is a process that improves the texture of glass fibers and chemical fibers, giving them elasticity and bulk by giving filamentous fibers a natural fiber-like crimp form, such as wool. As for the bulking method, it is preferable to classify the type of 05 ill into, for example, stretchable fibers, non-stretchable fibers, etc., and select an appropriate method according to the classification.

As the binder of the present invention, phenol resin, butyral resin, phenoxy resin, epoxy resin, melamine resin, etc. can be used.

Phenolic resin refers to a resin obtained by combining one or more phenols such as phenol and cresol with formaldehyde or a compound that is a source thereof. Modified phenolic resins modified with cashew nut oil, polyvinyl butyral, vegetable oil, melamine, epoxy compounds, etc. may also be used. In addition, unmodified phenol resin is preferable in terms of heat resistance.

As the inorganic filler of the present invention, one that is excellent in both anti-slip properties and low aggressiveness of mating materials in a well-balanced manner is used singly or as a mixture. In other words, materials that are excellent in both of these properties include barium sulfate, calcium carbonate, etc. (group X).
Materials that have excellent anti-slip properties but are not excellent in low aggressiveness of mating materials include diatomaceous earth, alumina, and silica (Y group), while those with the opposite performance include graphite, talc, etc. (group 7). There is. The inorganic filler of the present invention includes (1
) consisting of at least one type of group X, (2) X
At least one of group Y or at least one of group 7! ! A mixture of I or (3) a mixture of at least one of the group Y and at least one of the seven groups can be used. Note that those consisting of at least one member of the Y group or at least one member of the two groups are not used because their properties are unbalanced, and the same applies to thermal black. This is because thermal black alone causes slippage under severe conditions. The types of components of the filler and their blending ratios are appropriately selected depending on the purpose and use. 11 of the present invention ((as a filler,
One or both of barium sulfate and calcium carbonate are preferred.

Rubber and other compounding agents used in the present invention (e.g. organic powders such as cashew dust and rubber dust, aluminum,
Metal powders such as iron and zinc, vulcanizing agents, vulcanization accelerators, vulcanization aids, etc.) and metal wires are not particularly limited, and may be used in various ways depending on the purpose and application, such as clutch facings or brake linings. You can choose one that is well known.

The rubber is preferably synthetic rubber such as SBR or NBR. A relatively large amount of rubber is used for the clutch facing.

Further, when manufacturing a friction material using the widely used spiral woven method, rubber does not need to be blended. Brass wire is preferable for the metal wire.

The blending ratios of the components of this friction material are set so as to have all the properties practically required for this type of friction material, as described below. In addition, each of these 91 formulations was tested by changing the proportions of each component, centering on the standard proportions of the following representative compounding ingredients, and the performance of each was evaluated, and the following practically required characteristic values were obtained. I decided to equip it.

[Practically required characteristic values]

Shutter degree 0.1G [F, average IIJrs coefficient 0°3
~o, 45, wear ff16. OX 10-4mm37
kg・m or less, aggressiveness to mating material 0.05ml or less, burst strength i 4000 rpm or more, excellent in actual vehicle shudder test when starting, and no actual vehicle slippage under severe conditions.

[Typical compounding ingredients and their standard compounding ratios] Glass fiber 2
5 parts by weight, 17 parts by weight of phenolic resin, 1 part by weight of barium sulfate and calcium carbonate mixture, 14 parts by weight of 5BR, 5 parts by weight of cashew dust, 12 parts by weight of crosslinking agent, 4 parts by weight of brass wire.

The blending ratios of the components of the present friction material, which were determined in consideration of the above, are as follows, including all 100 parts of the friction material.

The blending ratio of bulky heat-resistant fibers is 20 to 30 parts by weight. The degree of shudder is 0 for all 30 weights or more.
．． This is because if it is more than 1 G and less than 1 part of 20 mfi, the burst strength will be less than 14,000 rpm, which is not preferable.

The blending ratio of the binder is 5 to 25 parts by weight, preferably 8 to 25 parts by weight. This is because if the amount is more than 25iI2m parts, the coefficient of friction will be less than 0.3, and if it is less than 5 parts by weight, the coefficient will be more than 0.45, which is not preferable.

The blending ratio of the inorganic filler is 10 to 30 parts by weight,
Preferably it is 12 to 30 layers. This is because if it is less than 10 parts by weight, the coefficient of friction will be less than 0.3, and if it is more than 30 parts by weight, the coefficient will be less than 0.45, which is not preferable.

The blending ratio of other components including rubber is 15 to 45!1
1! fi) section. Among these, the blending ratio of rubber is 5~
20 layers are preferred. If the wear rate is less than 5, the wear rate is 6.
OXl 0-4mm 37kg-m or more, 20
If the amount is more than 1 part by weight, the coefficient of friction will be less than 0.3; this is because it may lead to bacteria, which is undesirable.

The blending ratio of other components, that is, compounding agents other than the above-mentioned compounding agents and metal wires, is the balance of all the above-mentioned compounding agents, and usually the other compounding agents (crosslinking agent, each additive, etc.) are 10%
There are 2 to 5 layers of metal wire in the mouth part of the ~20 layers.

Any known method can be applied to the method of manufacturing the friction material of the present invention, and there are no particular limitations. A typical example of this is the semi-molding method, which involves impregnating the friction material with a binder, drying, rubber coating, drying, winding into a loop, pressurizing and heating molding, after-curing, and polishing. !
This is the method of building A.

〔Example〕

The present invention will be explained below with reference to Examples.

Example 1 E-glass single fibers having a fiber diameter of 6 μm were converged and subjected to an opening process such as a strand, and then the fibers were subjected to a bulking process. This fiber was impregnated with a phenolic resin solution prepared with methanol and then dried at 120° C. for about 1 hour until the methanol was sufficiently volatilized to rust the phenolic resin. After this, SBR is mixed with sulfur, accelerator CZ, and inorganic filler (barium sulfate and lucium carbonate a mixture) using a rubber roller, and the rubber content is dissolved with toluene to adjust the viscosity to 10,000 to 20,000 Cps. The rubber is coated by impregnating it into a coating bath. At this time, a brass wire is simultaneously wound around the fiber. After that, after thoroughly air-drying and winding it into a loop shape with a winding machine, 1
Pressure and heat molding is performed for 3 minutes using a compression molding machine set at 65° C. and 100 ko/Cl12. At this time, treat it with gas several times at first.

The obtained molded product was heated in a heating furnace at 150°C for 6 hours and then heated at 200°C.
℃ for 3 hours and 250℃ for 3 hours, and both the front and back of the friction surface were polished to obtain an I'J friction ring material.

In the total of 100 parts of this friction material, each component was contained in the proportions shown in Table 1 by weight.

In order to examine the performance of the above-mentioned yJ friction material, we conducted tests on the average friction coefficient, minimum yield coefficient, amount of wear, aggressiveness of opposing materials, shudder on an actual vehicle when starting, and sliding on an actual vehicle under severe conditions. The results are shown in Table 2.

In addition, this test method is I! The J friction coefficient and wear amount were tested using an inertial dynamometer at 200"C.
``Slip'' was measured by actually mounting the IIIW material on a car (FF passenger II and 4-wheel drive passenger car) and conducting actual vehicle tests under severe conditions.Table 2: In the solid car slipping test, O means no slipping, and × means slipping. has been recognized.

Examples 2 to 5 and Comparative Examples 1 to 2 In Examples 2 to 5 and Comparative Examples 1 to 2, except that the proportions of each compounded component were as shown in Table 1,
A friction material was obtained in the same manner as in the example.

In Comparative Example 1, a mixture of diatomaceous earth, calcium carbonate, barium sulfate, and uAyJ was used as a filler, in Comparative Example 2, thermal black was used as a filler, and in Comparative Examples 1 and 2, cash dust was not blended. do not have.

Each test of the above friction material was conducted in the same manner as in Example 1, and the results are shown in Table 2. According to this result, all of the Ha materials of Examples 1 to 5 meet all the characteristic values practically required for friction materials described in tti. That is, this friction material has an average friction coefficient of 0.39 to 4.44 and a wear opening of 6. OXlo-4 mm3/kQ·m or less, the aggressiveness to the mating material is 0.009 to 0.018 mm, the actual vehicle shudder performance is 0.1 G or less, and no actual vehicle slippage occurs. On the other hand, in Comparative Example 1, the aggressiveness of the opposing material was 0.053 mm.
And the actual vehicle shudder performance is 0.120G,
In Comparative Example 2, actual vehicle slippage occurs and the characteristic values deviate from the above-mentioned practical characteristics.

From the above, this friction material has excellent friction properties, excellent shudder performance at the time of starting in actual vehicle tests, and also prevented slipping under severe conditions, making it an extremely useful friction material for practical use.

〔Effect of the invention〕

1≠The rubbing material of the present invention contains bulky processed heat-resistant fibers such as glass fibers in 100 parts by weight.
30 parts by weight, 5 to 25 parts by weight of binder, 10 to 30 parts of inorganic filler, and 15 to 4 parts of other components including rubber.
It is characterized by a total of 4 + ll's with 5 layers. Therefore, this friction material has a shudder level of 0.1 G or less, an average friction coefficient of 0.3 to 0.45, and an aggressiveness of opponent material of 0.05 mm.
Hereinafter, wear m6.0X10-4 mm3/k (1・m
Below, the performance of the actual vehicle shudder test and the harsh conditions (
(FWD passenger cars, 4-wheel drive passenger cars)) Meets all conditions for no actual vehicle slippage. Therefore, this friction material can be used without sacrificing the general characteristics of a friction material, such as coefficient of friction, wear, and strength, and can also be used to reduce friction when starting a specific vehicle.
It does not have the disadvantage of causing FF passenger cars, 4
There is no drawback that slippage occurs even when used under severe conditions in wheel drive passenger cars and the like. In other words, this IIJyA material is
It has excellent balance performance in practical terms and is extremely useful for vehicles.

Claims (2)

[Claims] (1) In 100 parts by weight, bulked glass fiber,
20 to 30 parts by weight of bulky processed fibers made of at least one of heat-resistant fiber groups such as phenol fibers and carbon fibers, 5 to 25 parts by weight of a binder, and 10 to 30 parts by weight of an inorganic filler. and other ingredients including rubber1
A friction material comprising 5 to 45 parts by weight. (2) The friction material according to claim 1, wherein the binder is a phenolic resin, and the inorganic filler is one or two of calcium carbonate and barium sulfate.