KR870000964B1 - A friction material - Google Patents

Abstract

This forming friction material is composed of a inorganic or organic texture, a inorganic packed material, a heat-hardened synthetic resin, which has heat stability in 200-400≰C, and 15-50% one of the following cement flour, 1) 75-50% of mixed carbon, a mixture of 90- 75% oil coke and 10-30% black lead carbon, and 25-50% of stainless alloy iron. 2) 75-50% of mixed carbon, a mixture of 90-70% oil coke and 10-30% black lead carbon, and 25-50% of tungsten alloy iron or molybdenum alloy iron. 3) 75-50% of mixed carbon, a mixture of 90-70% oil coke and 10-30% black lead carbon, and 25-50% of metal iron.

Description

Molded Friction Material

BACKGROUND OF THE INVENTION 1. Field of the Invention [0001] The present invention relates to a molded friction material required for an industrial friction member for light or heavy duty automobile brakes, train wheelsets, clutches, or heavy toes.

Particularly, in the present invention, the main component of the filler is a cermet powder of a specific type, which is cermetized and powdered by mixing a mixed carbon made of oil coke and graphite carbon with stainless alloy iron, tungsten alloy iron and molybdenum alloy iron or metal iron, respectively. It relates to a molded friction material configured to be.

Conventional molded friction materials include the disclosures of the applicant's prior invention patent No. 16455 (hereinafter referred to as "prior invention"), which is disclosed in Korean Patent Publication No. 83-2534.

This prior invention is a molded friction material formed by replacing some or all of the inorganic fillers, which are components of the friction material, with a cermet powder (hereinafter referred to as "cermet powder (D)") of the "oil coke and metal iron" series. As a result, it was found that the defects described in the following sections were implied.

end). The friction material of the present invention contains about 25-35% of the iron component in the cermet powder (D) used as the main component of the filler. When the friction material is exposed to the air for a long time, the cermet powder (D) becomes air. It is easily oxidized by rust, so it has a drawback that the friction action is sharply reduced. B) In addition, the friction material of the preceding invention has a great characteristic of adhesive friction, so it is well braked by friction, but excessive heat is caused by excessive friction. It is generated, and the oxidation is measured, as well as the lack of high temperature friction stability, can not be smooth and flexible braking, and also has the disadvantage that is caused by the friction noise, c) In addition, this prior invention friction material contains asbestos in the composition In the manufacturing process of the friction material as well as the use of asbestos dust harmful to the human body there was a defect that causes pollution.

In addition to the foregoing invention, U.S. Patent No. 4505963 of "Ogiwara" discloses stainless steel, aluminum, nickel, zinc, chromium, and the like to prevent the disadvantage of being oxidized and rusted on the surface of a disc brake pad (hereinafter referred to as "pad"). The single or alloy is optionally shown. It has been reported to mix the solution and apply it to the surface of the pad.

However, this is simply to prevent the rust (oxidation) of the surface of the pad and even this is not composed of the above-mentioned antioxidant composition, but only applied to the surface, the invention of this US patent and the present invention are separate from the configuration to be.

In addition, U.S. Patent No. 4217255, U.S. Patent No. 4278584, U.S. Patent No. 4369263, Japanese Patent No. 59-22984, Japanese Patent No. 59-24772 and the like also known as asbestos friction material, carbon fiber, metal, glass It has been published to form friction materials by selectively and simply physically blending fibers, organic fibers, graphite, carbon black, silica, rubber, thermosetting resins, cashew oil, barium sulfate, aluminum, calcium carbonate, alumina and the like.

These known methods do not use a cermetized at a high temperature (for example: 1400-1600 ° C) as in the present invention, it is apparent that the known invention and the present invention is a separate method because the invention itself is different.

Japanese Patent No. 58-208374 is an iron-based sintered friction material, which is not an organic friction material, and can not be compared because the production method and the composition itself are fundamentally different from the friction material of the present invention, which is molded from synthetic resin. In addition, as a drawback of the prior art friction materials, the excessive occurrence of rust due to the severe oxidation of the friction material and the overheating caused by excessive adhesion friction, resulting in oxidative action, lack of high temperature friction stability, lack of flexible braking, noise generation, asbestos Defects such as pollution dust generation and excessive wear loss.

The inventors of the present invention have produced a friction material that almost completely eliminates these drawbacks, and it is the object of the present invention to accomplish this.

Hereinafter, the present invention will be described in detail.

The present invention is a fiber selected from inorganic fibers and organic fibers that are harmless to a known human body, an inorganic filler optionally selected from known fillers, and one kind selected arbitrarily from thermosetting synthetic resins having thermal stability at a temperature of 200-400 ° C. In the above-mentioned thermosetting synthetic resin mixture, a cermet powder selected from the following A), B) and E), that is, A) a mixture composed of mixed carbon and stainless alloy iron mixed with oil coke and graphite carbon is a known cermetization condition. , Cermet powder (A) and B) obtained by pulverizing after heating to a temperature of 1400-1600 ° C. and the alloy iron selected from the same hybrid carbon, tungsten alloy iron and molybdenum alloy iron as in (A) above; The cermet powder (B) obtained by treatment under the same cermetization conditions and E) a mixture composed of the same carbon and metal iron powder as in the above (A) was subjected to the cermetization conditions as in the above (A). By adding a cermet powder arbitrarily selected from the cermet powders (E) obtained by treatment as a main component of the filler, a specific mold mixture is formed to form a friction material, and the specific mold mixture is put in a known mold and known molding. The invention relates to a molded friction material characterized by forming a friction material by heating and pressing at a pressure and a known molding temperature.

The mixed carbon herein is preferably a mixture of 90-70% by weight of oil coke and 10-30% by weight of graphite carbon, and the composition of the cermet powders (A), (B) and (E) above Most preferably, 75-50% by weight and 25-50% by weight of a metal component selected from stainless alloy iron, tungsten alloy iron, molybdenum alloy iron, and metal iron are mixed.

Therefore, it is preferable that the ratio of adding each of the cermet powders (A), (B) and (E) in the component mixture of the friction material of the present invention is in the range of 15-50% by weight based on the weight of the friction material. Moreover, if only the ratio of the composition component which comprises each said cermet powder (A), (B), and (E) is concretely indicated, the cermet powder (A) is an oil coke 90- It is composed of 75-50% by weight of mixed carbon composed of 70% by weight and 10-30% by weight of graphite carbon and 25-50% by weight of stainless alloy steel.The cermet powder (B) is composed of 90-70% by weight of oil coke and It consists of 75-50% by weight of mixed carbon of 10-30% by weight of graphite carbon and 25-50% by weight of tungsten alloy iron and / or molybdenum alloy iron, and the cermet powder (E) is 90-70 weight of oil coke. It is composed of 75-50% by weight of mixed carbon and 25-50% by weight of metal iron powder composed of% and 10-30% by weight of graphite carbon.

In addition, in the cermetization composition of the present invention, in addition to the composition described above, a cermetization aid may be added and used as in the present invention. For example, the adjuvant which becomes mixtures, such as magnesium, is mentioned. The cermet raw material mixture composed of the above components is treated with a reducing atmosphere at a firing temperature (for example, 1400-1600 ° C.), and then cooled and pulverized to provide a cermet powder (A), (B) and ( E)

The reason for the cermetization is that the graphite carbon, oil coke, and each metal are combined into a powder state by the high temperature treatment of the cermet, and the carbon is changed to a semi-lubricating substance, and the mixed carbon exhibits the unique characteristics of each carbonaceous material. This is because they found that they complement each other and change to the most desirable state as a friction material.

The cermet powders (A), (B), and (E) allow the effective friction material of the present invention to be produced by the properties of the cermet powder.

Therefore, even in extreme cases, for example, even if the composition is assumed to be the same as the composition of each of the above-mentioned cermet powder, the characteristic performance as a friction material of the present invention cannot be obtained without the high temperature treatment of the cermetization. It may be interpreted. The composition of the iron alloy used in this specification is as follows.

“Stainless alloy iron” means ferroalloy of 7-27% by weight of nickel and / or chromium and 93-73% by weight of metal iron, and “tungsten alloy iron” means 5-7% by weight of tungsten And ferroalloy of 95-93% by weight of metallic iron, and "molybdenum alloy iron" means ferroalloy of 5-7% by weight of molybdenum and 95-93% by weight of metal iron. In addition, the term "inorganic fibers" means at least one inorganic fiber selected from known inorganic fibers other than asbestos, such as glass fiber, star wool, steel fiber, ceramic fiber, silicate fiber, leusilica fiber and carbon fiber. it means.

“Organic fibers” are fibers selected from fibers such as cellulose-based fibers, aliphatic polyamides, polyacrylonitriles, aromatic polyamides, aromatic polyesters, and the like, and heat-resistant organic materials whose fibrous structures are not deformed by frictional heat. It means fiber.

“Inorganic fillers” are known powdered calcium carbonate, barium sulfate, alumina, calcium sulfate, talc, kaolin, mullite calcium silicates or powdered silicates, fine powdered silica powder metals (e.g. copper, iron And inorganic powder fillers such as brass aluminum, zinc, and the like, and other metal oxides. These fillers may be optionally selected and used in the present invention. “Thermosetting synthetic resins” means phenolic resins, melamine resins, unsaturated polyester resins, epoxy resins or mixtures thereof or other synthetic resins, which are used for molding binders and are known in molding friction materials. At least one selected from synthetic resins having thermal stability at 200 to 400 ° C. is added and used.

In addition, the above-mentioned synthetic resin may be mixed with a plasticizer for molding as needed, and examples thereof may include addition and use of plasticizing aids for forming cashew nut oil, cashew dust or other known materials.

The structural features and the effect of the molded friction material of the present invention constituted as described above will be described in detail.

As described above, the present invention is characterized by using a mixed carbon obtained by mixing oil coke and graphite carbon as its carbonaceous raw material in the preparation of each of the cermet powders (A), (B) and (E). It is one of the features of the present application that it excludes the addition of a single piece of oil coke or graphite.

That is, in the prior invention, the cermet powder was prepared by adding only iron as a metal component to one oil coke, and in the other prior art, stainless steel, aluminum, nickel, chromium, or an alloy thereof is added. The sintered friction material was prepared by coating on the surface of or by sintering to a low melting point material at a temperature of 700-900 ° C by mixing with a known friction material, not based on synthetic resin, based on iron. By forming a molded friction material in which any of the cermet powders (A), (B), and (E), which are made of the same hybrid carbon and subjected to cermetization high temperature treatment, is added as a main component of the filler,

(1) Improve the durability of the friction material, and (2) Improve the closed end of excessive frictional heat and inadequate braking due to the adhesive friction of the friction material of the known prior art. It is characterized by forming a friction material having a friction coefficient suitable for performance, and (3) obtaining a molded friction material that provides friction flexibility and smooth and efficient braking effect. In the case of the cermet powder (A), stainless alloy iron is used, and in the case of the cermet powder (B), tungsten alloy iron or molybdenum alloy iron is used. There is an example of adding and using, but there are no examples where the mixed carbon is cermetized by mixing mixed carbon with this stainless alloy iron and a friction material is produced from the cermet powder.

Moreover, in the past, when 0.3% or more of carbon component is contained in the corrosion-resistant ferroalloy etc., it was known that corrosion resistance is reduced.

On the other hand, in the cermet powders (A) and (B) of the present invention, since the carbon component is mixed in an excessive amount of more than 0.3%, there is a fear that there will be no corrosion resistance.

However, in the cermet powders (A) and (B) of the present invention, the cermet powders (A) and (B) are contained in an amount of 25-50% of the ferroalloy and in an excess of 75-50% of the mixed carbon. Although manufactured, the corrosion resistance of the alloy steel containing less than 0.3% was improved or showed almost the same degree of corrosion resistance.

The cermet powder (A) or (B) of the present invention is a friction material having excellent corrosion resistance and abrasion resistance and smooth friction braking properties even though it contains an excessive amount of carbon components. It is one of the other features.

Moreover, the characteristic result which this invention possesses also exists in the improvement structure of my prior invention. In this prior invention, as a specific ingredient constituting the friction material, a cermet powder of “C + Fe” series was added as a main component of the filler as in the present invention. As a raw material of “carbon-based” oil coke only It was used.

As described above, the friction material of the present invention has a great adhesion frictional property and a large braking heat generation.

In addition, it has been found that there are disadvantages of noise generation at the time of friction braking, and that the inclusion of defects such as failure to maintain a desirable range of friction coefficient and not smooth braking is included later.

These closed ends are "carbon-based" raw materials, as in the preceding invention, not merely oil coke, but friction material using a mixed carbon (oil coke + graphite carbon) and cermet powder (E) made of metal iron. Raised by constructing

As such, the oxidizing property of the metal iron component was not improved in the friction material using the cermet powder (E), but it was found that the friction coefficient was maintained in an appropriate range, and thus, the smooth and efficient braking performance was exhibited. The factor of this effect is interpreted to be due to the hybrid carbon, which is one of the important factors to prove that the present invention is an improvement of the prior invention.

Referring to the production of the molded friction material of the present invention as described above with reference to Examples.

"Parts" which are units indicated in Examples 1-1 to 1-5 below are "parts by weight" unless otherwise specified.

Example 1-1

Formation of the cermet powder (A) and its molded friction material

100 parts of mixed carbon are prepared by mixing 70 parts of oil coke powder and 120 parts of graphite carbon in a 120 mesh passage. Separately, 100 parts of a powder for a known 18-8 stainless alloy, in which 8 parts of nickel powder and 18 parts of chromium powder were mixed, was prepared in 74 parts of metal iron powder.

25 parts of the above stainless steel powder and 75 parts of the mixed carbon are mixed to form 100 parts of a cermetization raw material mixture, and a base component selected from 2 parts of anhydrous silicic acid, calcium oxide and magnesium oxide in 100 parts of the raw material mixture. After adding a negative cermetization aid, it is heated and sintered to a known cermetization temperature of 1400-1600 ° C. under reduced atmosphere and powdered at room temperature to obtain a cermet powder (A).

Using a cermet powder (A) thus obtained, the same mixture as in Example 3 is mixed in the composition table below, and a molding mixture is formed by adding and mixing phenol resin and all other ingredients in a conventional manner for a known friction material. It puts into a metal mold | die and heat-press-moldes to well-known shaping | molding temperature 160-190 degreeC, and forms the molding friction material to which the cermet powder (A) of this invention was added.

Example 1-2

Formation of the cermet powder (B) and its molded friction material

All the conditions were the same as in Example 1-1, except that the stainless alloy powder used in Example 1-1 was replaced with tungsten alloy powder consisting of 95 parts of metal iron powder and 5 parts of tungsten powder to obtain a cermet powder (B). Using this cermet powder (B), the same composition as in Example 5 was mixed in the following composition table, and the molded friction material to which the cermet powder (B) of the present invention was added was molded by the method of Example 1-1 and the molding method. Form.

Example 1-3

Formation of the cermet powder (B) and its molded friction material

Perform all the conditions as in Example 1-2, but replace only 5 parts of the tungsten powder used in Example 1-2 with 5 parts of molybdenum powder to obtain a thorough powder (B), and use this cermet powder (B) to obtain the following composition table. In the same manner as in the composition of Example 8, the same method as in Example 1-1 was used to form a molding friction material.

Example 1-4

Formation of the cermet powder (E) and its molded friction material

This embodiment relates to the progressive improvement of the prior invention. The main element of the advanced construction is a carbonaceous raw material that corresponds in forming a “carbon + metal iron” series cermet, without using only oil coke as in the prior invention. It is in the addition of "mixed carbon" which is called "oil coke + graphite carbon".

The performance resulting from this configuration is to form a molded friction material that has a smooth and noise-free braking action by significantly reducing the adhesion friction and bringing the friction coefficient to an appropriate range for the final product.

In carrying out this, all the conditions are carried out in the same manner as in Example 1-1, except that only the stainless alloy powder mixed in 100 parts of the cermet raw material mixture is replaced with metal iron to obtain the cermet powder (E). This cermet powder (E) is mixed in the composition table below in the same manner as in the composition of Example 2 to form a molded friction material by the same molding method as in Example 1-1.

[Example 1-54]

Metal iron (Fe), nickel (Ni), chromium (Cr), tungsten (W) used to obtain the cermet powders (A), (B) or (E) of Examples 1-1 to 1-4. And each of the molybdenum (Mo) in terms of the weight of each metal in the corresponding amount of iron oxide (FeO or Fe ₂ O ₃ ), nickel oxide (NiO or Ni ₂ O ₃ ), chromium oxide (Cr ₂ O ₃ ), Replace with tungsten oxide (WO ₃ ) and molybdenum oxide (MoO), and other conditions were carried out in the same manner as in Examples 1-1 to 1-4, and the cermet powders (A), (B), (E) and the like were Get

[Examples 2 to 13 (The composition of the cermet powder-added molding friction material)]

In Examples 1-1 to 1-5, the cermet powders (A), (B) and (E) and a molding friction material forming method (manufacturing method) were exemplified. Therefore, the example regarding the detail of the friction material component composition which adds cermet powder (A), (B), (E) is illustrated in Examples 2-13 described in the following composition table. However, in Examples 2 to 13. The composition ratio of the cermet powders (A), (B), and (E) to be displayed is not a composition ratio meaning absoluteness, but merely an example of adding the cermet powder.

Therefore, the scope of the present invention is not limited only to those of Examples 2-13 of this composition table.

[Composition Table (unit wt%)]

Test score example (constant friction test)

The results of the constant speed friction test measured by the test method of JISD-4411 regarding the wear rate and the friction coefficient for each temperature of the friction material of the present invention according to the examples described above are shown in the following test table.

[Test Table]

As shown in the test table, the molded friction material of the present invention maintains the most appropriate uniform friction coefficient since the friction coefficient has a range of 0.4-0.5 at a friction temperature of 100-350 ° C., in particular, high temperature friction of 350 ° C. Also in this table, the stability of the friction coefficient and the reduction of the wear rate are remarkable, and it can be seen from this table that the performance as a friction material is greatly improved than the conventional one.

When all the above descriptions are put together, it can be seen that the present invention is an advanced and distinct invention rather than the prior invention of the addition of a cermet powder of "C + Fe" series. In addition, the test results regarding the frictional resistance ratio and the oxidation degree of the molded friction material of the present invention are as follows.

Friction Resistance Test

This frictional resistance ratio test is not a test method of JISD-4411, but a test method independently devised by the applicant.

The sample piece (I) of the molded friction material of the preceding invention (Patent No. 16455) which added the cermet powder of "65% of oil coke carbon + 25% of Fe25% + cermetization adjuvant" by 50%, and said The sample piece (II) and the cermet powder (E) of the molded friction material prepared by adding the same amount of the cermet powder (A) or (B) as the sample piece (I) to the same amount as the sample piece (I). Table II below shows the results of tests on a tester equipped with a 5,000-rpm sodium friction plate using a sample piece (II) of the molded friction material added as a comparative sample piece and a standard cast iron sample piece as a standard sample piece. As shown in this table, it can be seen that the abrasion resistance ratios of the specimens (II) and (III) were significantly improved compared to the specimen (I) of the preceding invention.

The wear resistance ratio here is 2.4 mm of the worn thickness of the standard specimen (cast iron), and 0.3 mm, 0.2 mm, and 0.2 mm of the worn thickness of the specimens (I), (II) and (III), respectively. The reciprocal of the value obtained by dividing is expressed as the wear resistance ratio (non-wear resistance).

In the values shown in this table, the sample piece (II), which is the friction material to which the cermet powder (E) of the present invention is added, is almost identical to the friction material of the prior invention to which the cermet powder of the prior invention is added in terms of oxidation degree. It is proved that the wear resistance ratio has increased significantly.

The effect of improving the wear resistance ratio is proved to be due to the use of the cermet powders (A), (B) and (E) in the present invention.

Oxidation Degree Test

This degree of oxidation test was also performed independently.

Each of the friction materials to which the cermet powders (A), (B) and (E) were added, and the friction material to which the cermet powder was used in the present invention were formed into a powder of 120 mesh bottles, respectively. Under saturated steam at 100 ° C., the resultant was allowed to stand for about 10 days in a mixed gas for oxidation test in which the same temperature and the same volume of air were mixed.

As a result of this test, the ratio of the oxidation amount of the friction material to which the cermet powders (A) and (B) which were used in this order with respect to the oxidation amount of the friction material to which the cermet powder (D) used in the present invention was added is 1 / 30-1 / 50.

This result means that the acid resistance of the friction material to which the cermet powder (A) and (B) is added is 30 to 50 times higher than that of the friction material to which the cermet powder is used in the present invention. On the other hand, the oxidation resistance of the friction material added cermet powder (E) is similar to the friction material of the prior invention. Therefore, the friction material to which the cermet powder (E) is added does not significantly improve the oxidation resistance, but reduces the frictional adhesion while improving the wear resistance ratio as described above. It shows that there is a characteristic in forming the friction material held by. In the "degree of oxidation" described in Table II, the + sign indicates the degree of oxidation, meaning that the degree of oxidation increases as the number of + increases, and that the degree of oxidation decreases as the number of + decreases.

TABLE II

As can be seen from the above, the molded friction material of the present invention has a friction coefficient, so the friction braking is smooth and the friction coefficient due to oxidation and heat generation is extremely low, and the excessive frictional resistance due to adhesive friction is greatly reduced. It is evident that this is an invention of a friction material having a significantly reduced effect.

It is to be understood that the appended claims do not limit the invention, and that various modifications and changes related to the subject matter of the invention fall within the scope of the invention.

Claims (3)

One or more fibers selected from known inorganic fibers and organic fibers that are harmless to the human body, known inorganic fillers, and synthetic resins that may be added with plasticizers and are made from known thermosetting synthetic resins having thermal stability at temperatures of 200 to 400 ° C. In the molded friction material or its raw material composition constituted as a mett powder, the following groups (A), (B) and (E), (A) 75-50% by weight, 90-70% by weight oil coke and 10- Mixed carbon mixed with 30% by weight graphite carbon and cermet powder of 25-50% by weight stainless steel, (B) 75-50% by weight, 90-70% by weight oil coke and 10-30% by weight Cermet powder consisting of mixed carbon mixed with% graphite carbon and at least one ferroalloy selected from 25-50% by weight tungsten alloy iron and molybdenum alloy iron, (E) 75-50% by weight 90 Mixed carbon mixed with -70% by weight oil coke and 10-30% by weight graphite carbon, 2 A molded friction material characterized in that it contains 15-50% by weight of at least one of the cermet powder which is 5-50% by weight of metal iron and the cermet powder selected from. The molded friction material according to claim 1, wherein the stainless alloy iron constituting the metal component of the cermet powder (A) is 7-27 wt% of Ni and Cr and 93-73 wt% of Fe. The molded friction material according to claim 1, wherein the tungsten alloy iron and molybdenum alloy iron constituting the metal component of the cermet powder (B) are 5-7 wt% W or Fe 95-93 wt% Fe.