JPS6350381A - Carbonaceous abrasive material - Google Patents

Abstract

(57) [Abstract] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a carbonaceous friction material having a large low-speed rfl friction coefficient, which is obtained by impregnating a carbon material with a metal-free compound having a relatively low melting point.

[Conventional technology]

'gFriction materials, especially brake materials, not only have excellent friction properties, but also have a heat capacity that can sufficiently absorb frictional heat.
It is also required to be lightweight.

In particular, materials such as aircraft and racing cars are not only used under extremely harsh conditions, but also require materials that are slightly lighter.

Carbonaceous friction materials have a friction coefficient that does not decrease even under harsh conditions.
On the contrary, it has advantages such as high heat capacity, low specific gravity, etc., and is ideal for this purpose, but its disadvantage is that it is weak in strength, and it only causes safety problems such as cracking. Therefore, there was a lot of rP and wear, making it difficult to put it into practical use.

For this reason, reinforcement with carbon fibers (so-called carbon lining/carbon insulation material, hereinafter referred to as C-C composite material) has improved the strength and reduced wear to a practical level. Since carbonaceous friction materials have excellent performance other than wear, they are also used in aircraft, racing cars, etc. as high-performance friction materials due to the above-mentioned improvements to reduce wear.

However, although carbonaceous friction materials have excellent properties and exhibit a high coefficient of friction under severe conditions, they have the disadvantage that the coefficient of friction is somewhat low under gentle conditions. Especially the coefficient of friction when stopping,
The so-called Shizuyu t? The tl coefficient is low and the performance as a parking brake is insufficient.

Conventionally, in order to adjust friction characteristics, various friction adjustment materials have been used that are compatible with FJ abrasion. For example, in a resin-based friction material, right-n type rubber, cashew, free graphite, alumina, silica, metallic iron, copper, aluminum, etc. are used.

[Problem that the invention seeks to solve]

By the way, since carbonaceous friction materials are manufactured by firing at high temperatures of 1000°C or higher, most friction modifiers deteriorate or volatilize, so commonly used friction modifiers are It cannot be added to raw materials for carbonaceous friction materials.

The present inventors focused on the fact that carbonaceous friction materials have a large number of fine pores, and even if it is not possible to blend FM friction adjustment material during molding of carbon materials, friction can be adjusted by impregnating the fired product with this material. Thinking that it would be effective as a material, they conducted extensive research and discovered that metal inorganic compounds are effective.

The present invention was made based on the above discovery, and the friction coefficient at low speed is 1'l at ft speed! It is an object of the present invention to provide a carbonaceous friction material having a friction coefficient equal to or higher than the friction coefficient.

[Means for solving problems]

The present invention has been made to achieve the above objects,
The gist of B is that the melting point is between 200 and 10 in the network pores of the carbon material.
It is a carbonaceous 1'J rubbing material impregnated with a metal inorganic compound at 00°C.

[Specific structure and operation of the invention]

The present invention will be explained in detail below.

The carbon material used in the present invention is a carbonaceous friction material, for example, carbon LyA navy blue woven fabric or non-woven fabric mat with pitch,
Impregnated with a binder such as resin, pressed and fired, graphitized as necessary, short carbon fibers mixed with pitch, binder such as resin, shaped and fired, and graphitized as necessary. Known materials include those obtained by impregnating a thermosetting resin with a thermosetting resin, or cellulose fibers, which are then compressed, hardened, fired, and optionally graphitized.

The carbon material produced by impregnating the above-mentioned cellulose fiber with a thermosetting resin is called glass carbon, and the porosity can be adjusted by adjusting the firing time. Furthermore, the porosity of the CC composite material can be adjusted by repeating impregnation. The carbon material used in the friction material does not have a large number of fine pores, usually 10 to 20%, at most 30%, which is suitable for impregnating the S friction adjusting material. It is.

Also, r! Preferred metal inorganic compounds used as the J friction modifier include sulfides, halides, and cyanides of the A, rVA, and IB groups. For example, Sb
203. Sb 83, Bi 203.

Bi F3 , Bi 13 , Sn O,, Sn s
, pbo.

PbF2, PbCu2, Pb3r2
, PI) 12.

Cu CN, Cu Br, Cu I, AgCJ.

Examples include AU CN, A+J Sr, and AQ 2 S, but in addition to these metal inorganic compounds, Pb Cr 0
4.

PbSO4・PbO,AOzTe,A(+3POa
.

A(] 4 F20y, AG PO3, KB508
.

Qa s, Ca (PO3)2, TJBI', T
i I.

Ti2S, Ti233, FeAS2. Tj Ia
.

NiAs, NiS, V20S, VF3, [3
a02.

AS2 S3, MOO3, Li F, Li 3
POa etc. are effective. ”2 metal inorganic compounds [yo,
You may use not only one type but also a mixture of two or more types.

Some metal-free compounds are easily soluble in water, and in extreme cases they may become deliquescent. Materials that are easily soluble in water should be avoided for use in the present invention because they may absorb moisture in the air or become wet with water and flow out.

Furthermore, carbonaceous friction materials are used under severe conditions, and the impregnated friction modifier may decompose due to frictional heat. Therefore, the decomposition products should also have a friction-adjusting effect, and the metal inorganic compound remains as a metal after being decomposed and exhibits the above-mentioned function.

Furthermore, in order to impregnate the carbon material, it must be melted, so it is inappropriate to have a melting point that is too high; practically, the melting point must be 1000° C. or lower. Melting point is 1o
Anything below 0°C melts due to frictional heat and forms a thin film when rubbed. The film increases the coefficient of friction at low speeds. At 8'+i speed, the film melts and carbon material is deposited on the friction surface, resulting in a high rP friction coefficient.

If the decomposition product is metal, the decomposition product itself has the effect of increasing the low-speed friction coefficient, so there is almost no change in performance even if it is decomposed.

However, if the melting point is too low, it will easily melt and flow out under lukewarm heat, making it unsuitable as a friction modifier, and the temperature must be 200°C or higher.

Therefore, by impregnating a metal inorganic compound with a melting point of 200 to 1000°C that is difficult to dissolve in water, the FJf of the carbonaceous friction material at low speeds can be improved. The A factor can be increased.

〔Example〕

Next, the present invention will be explained by showing examples and comparative examples.

Example 1 A phenolic resin diluted with alcohol and ethanol at a ratio of 1:1 was mixed with a phenol resin diluted with alcohol and ethanol at a ratio of 1:1 to a mixture of (commercially available industrial use) door paper and water, and then molded using a sheet machine. In order to reduce the density of this molded product, it was further impregnated with phenol resin and fired. The bulk density of this fired product is 1.29/CId
Met. In order to further increase this bulk density, impregnation with phenol resin and firing are repeated until the bulk density reaches 1. f3!7
/cm' was made into a fired product.

This was graphitized at 2700°C.

Next, the graphitized carbon material was placed in an A-toclave, and the pressure was reduced to 2 Torr using a vacuum pump, and the temperature was heated using a lυ heater built into the autoclave. When the temperature reached approximately 100°C higher than the melting point of the compound, each of the molten metal compounds was injected into the autoclave and pressurized to 30'J/cm using argon gas. A carbonaceous friction material impregnated with a free compound was obtained.

The friction material obtained in this way was combined with a disk with a diameter of 200# and a thickness of 6M. Processed into a +gX45m pad,
Using an inertial wear test, the friction coefficient was measured at a speed of 501 y/hr, a surface pressure of 10 Kg/ci, and a speed of 3/hr of 1100 y/hr, a surface pressure of 20/9/d.

Example 2 A mat of approximately 5 cm long PAN-based carbon fibers was laminated, impregnated with coal tar pitch having a softening point of 85° C., and formed into a plate. This molded product is fired, and further]-
Impregnated with Lecoeur pitch, returned to F4 for firing, bulk density 1.6
9/l-m'. The crystal lattice constant of this is 6.85
After graphitizing to give the following properties, various metal-free compounds were impregnated as in Example 1 and Ji71. Kiran was processed in the same manner as in Example 1, and the inertia formula l! ! A rubbing test was conducted.

Example 3 An inertial friction test was conducted using a combination of the various pads prepared in Example 1 and a cast iron (Fe12) disk.

Example 4 The various pads prepared in Example 2 and cast iron (Fe12) disks were combined and subjected to an inertial friction test.

Comparative Example 1.2 Regarding the graphitized sample with a crystal lattice constant of 6.85, which was not impregnated with the metal compound of Examples 1 and 2, Example 1
It was processed in the same manner as above and an inertia friction test was conducted.

In Examples 1, 2.3.4, various metal inorganic compounds,
Table 1 shows the friction coefficients under various conditions for the impregnated friction materials and the friction materials of Comparative Example 1.2.

〔Effect of the invention〕

As described above, the carbonaceous friction material according to the present invention has an improved coefficient of friction at low speeds, completely eliminating the drawbacks of conventional carbonaceous friction materials.

Claims (1)

[Claims] A carbonaceous friction material characterized in that a metal inorganic compound having a melting point of 200 to 1000°C is impregnated into the pores of the carbon material.