JP2019059941A - Friction material composition, and friction material and member using the same - Google Patents

Abstract

To provide a friction material composition that has a constitution of low environmental hazard with the copper content not exceeding 0.5 mass%, and that yields a friction material effective for automobile fuel consumption improvement by having a good effectiveness characteristic, wear resistance and BTV characteristic, and furthermore by being light-weight; and also to provide a friction material and member using said friction material composition.SOLUTION: Provided is a friction material composition containing a binder, an organic filler, an inorganic filler and a fiber base material, and in which the content of copper as an element does not exceed 0.5 mass%, and in which a ferrous fiber or ferrous powder is contained by 1 to 3 mass% as well as wollastonite is contained by 10 to 30 mass% as the fiber base material.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a friction material composition suitable for a friction material such as a disk brake pad and a brake lining used for braking an automobile or the like, and a friction material and a friction member using the friction material composition.

  In automobiles and the like, friction materials such as disc brake pads and brake linings are used for braking. A friction material such as a disk brake pad or a brake lining plays a role of braking by friction with a disk rotor or a brake drum as a mating material. Therefore, not only the friction material is required to have an appropriate coefficient of friction (effect characteristics) according to the conditions of use, but it is difficult for the noise to occur (noise characteristics), the life of the friction material is long (wear resistance), etc. Is required. Further, not only safety but also comfort during driving is required to have a small torque vibration at the time of braking (BTV = Brake Torque Variation characteristic).

  Further, in recent years, weight reduction of automobiles has been demanded from the viewpoint of fuel efficiency improvement, and weight reduction of unsprung load, which is particularly effective, has been focused. Therefore, although reducing the weight of the friction material is effective for improving the fuel consumption of the automobile, materials having a high specific gravity, such as copper and zirconium oxide, are generally used as conventional friction materials.

  Copper is added for the purpose of imparting thermal conductivity to the friction material, imparting a reinforcing effect when used in a fiber shape, etc. For example, the weight loss of copper fiber reduces the matrix reinforcing effect at high temperature, and the abrasion resistance decreases. It will In addition, the loss of copper reduces the thermal diffusion efficiency at the frictional interface, and a local temperature gradient (heat spot) is formed on the disk rotor of the mating material, resulting in an increase in torque vibration. On the other hand, it is desirable not to add copper to the friction material from the viewpoint of contaminating rivers and lakes as wear powder.

  Zirconium oxide is an inorganic filler with a high melting point, and has a Mohs hardness higher than that of the counterpart cast iron, so it functions as an abrasive and its coefficient of friction decreases due to weight loss.

  As a remedy for the above-mentioned adverse effect, a method of replacing copper fibers with other high thermal conductivity materials and inorganic fibers and zirconium oxide with other lightweight abrasives has been studied.

  For example, magnesium oxide, which is an abrasive that does not use copper and has a lower specific gravity and higher thermal conductivity than zirconium oxide, and graphite having a high thermal conductivity, contains 45 to 80% by volume of friction material; A method of setting the ratio to 1/1 to 4/1 has been proposed (Patent Document 1).

  In addition, in order to reinforce the friction material, a method has been proposed in which wollastonite is added in a relatively large amount of 10 to 15% by mass together with metal fibers and mineral fibers (Patent Document 2).

  Moreover, the method of adding 2-30 mass% needle-like calcium carbonate for the purpose of reinforcement of a friction material is proposed (patent document 3).

JP, 2002-138273, A JP 2008-57693 A JP-A-5-105867

  In the friction material for brakes of Patent Document 1, there is an issue that it is difficult to improve various friction characteristics in a well-balanced manner because the addition amounts of magnesium oxide which is an abrasive and graphite which is a lubricant are extremely large. .

  Moreover, in the friction material for brakes of patent document 2, the total of the addition amount of a fiber base material increases extremely, causing the strength fall by the porosity increase of a friction material, and the pedal feel deterioration of the brake by the compression distortion amount increase. You

  Also, as in the method of Patent Document 3, when using acicular calcium carbonate for the purpose of reinforcing the friction material, calcium carbonate has a low specific gravity but a low melting point, and in particular, a composition containing no copper fiber, resistance at high temperatures Abrasion etc. will deteriorate.

  On the other hand, weight reduction can be achieved even by downsizing of the friction material, but when the friction area is reduced, the heat load per unit area of the friction surface increases, and particularly the composition which does not contain copper wear resistance Is a concern for the In addition, if the weight reduction is achieved by thinning the friction material, the product life will be shortened.

  Therefore, the present invention is a composition having a low environmental harmfulness in which the copper content does not exceed 0.5% by mass, and has good performance, wear resistance, BTV characteristics, and further light weight to improve the fuel efficiency of the automobile. It is an object of the present invention to provide a friction material composition that provides a friction material that is effective. Another object of the present invention is to provide a friction material and a friction member using the friction material composition.

  The present inventors, in order to achieve the above target, the copper content as an element does not exceed 0.5% by mass, and contains 1 to 3% by mass of iron-based fiber or iron-based powder, and a fiber base By containing 10 to 30% by mass of wollastonite, the weight reduction is achieved while the effect characteristics, the abrasion resistance, and the BTV characteristics are well-balancedly improved even if the copper addition amount is extremely small or does not contain copper. I found it possible.

The present invention relates to the following matters.
(1) A friction material composition comprising a binder, an organic filler, an inorganic filler, and a fibrous base material, wherein the copper content as an element does not exceed 0.5% by mass, iron-based fiber or iron-based A friction material composition containing 1 to 3% by mass of powder and containing 10 to 30% by mass of wollastonite as a fiber base.
(2) The friction material composition according to (1), which contains 1 to 10% by mass of magnesium oxide as an abrasive.
(3) The friction material composition according to (1) or (2), which contains 1 to 10% by mass of graphite as an inorganic filler, and the median diameter of the graphite is 1 to 30 μm.
(4) The friction material composition according to any one of (1) to (3), which contains 2 to 8% by mass of cashew dust as an organic filler.
(5) A friction material formed by molding the friction material composition according to any one of (1) to (4).
(6) A friction member in which the friction material according to (5) and the back metal are integrated.

  According to the present invention, when used as a friction material such as a disc brake pad or brake lining for automobiles, the copper content is suppressed to make the composition less harmful to the environment, and the good effect characteristic, the wear resistance, It is possible to provide a friction material composition which provides a friction material which has BTV characteristics and is lightweight so as to contribute to the improvement of the fuel efficiency of automobiles. Further, according to the present invention, it is possible to provide a friction material and a friction member having the above-mentioned characteristics.

It is a thermographic image of the disrotor at the time of BTV evaluation of the Example and comparative example of this invention.

  Hereinafter, the non-asbestos friction material composition of the present invention, and a friction material and a friction member using the same will be described in detail.

[Non-Asbestos Friction Material Composition]
The non-asbestos friction material composition of the present embodiment is a friction material composition containing a binder, an organic filler, an inorganic filler, and a fiber base material, and the copper content as an element is 0.5 mass% And containing 1 to 3% by mass of iron-based fiber or iron-based powder, and 10 to 30% by mass of wollastonite as a fiber base. In addition, said "copper content as an element" shows the content rate in all the friction material compositions of the copper element contained in copper, copper alloys, and copper compounds, such as fibrous form and a powder form.

  With the above configuration, the friction material and the friction member using the non-asbestos friction material composition of the present embodiment are generated at the time of braking as compared with the conventional product because the amount of added copper is extremely small or contains no copper. There is less copper in the wear powder, and because it is lightweight, it contributes to the improvement of the fuel efficiency of the automobile and is environmentally friendly, and exhibits well-balanced properties, good abrasion resistance and BTV characteristics in a well-balanced manner.

[Inorganic filler]
The friction material composition of the present embodiment contains an inorganic filler. The inorganic filler is included as a friction modifier in order to avoid the deterioration of the heat resistance of the friction material. In the present embodiment, as the inorganic filler, it is preferable to contain magnesium oxide, graphite and barium sulfate from the viewpoint of reducing the aggressivity to the facing material.

  The content of the magnesium oxide is preferably 1 to 10% by mass, more preferably 2 to 10% by mass, and still more preferably 3 to 10% by mass. The median diameter of the magnesium oxide is preferably 1 to 20 μm, more preferably 1 to 15 μm, and still more preferably 1 to 10 μm. By setting the median diameter of magnesium oxide to 1 μm or more, a good coefficient of friction and wear resistance are exhibited, and by setting the median diameter to 20 μm or less, the dispersibility in the friction material can be enhanced and the coefficient of friction can be stabilized.

  Moreover, it is preferable that it is 1-10 mass%, as for the content rate of the said graphite, it is more preferable that it is 1-9 mass%, and it is further more preferable that it is 2-8 mass%. The median diameter of the above-mentioned graphite is preferably 1 to 100 μm, more preferably 1 to 50 μm, and still more preferably 1 to 30 μm. By setting the median diameter of graphite to 1 μm or more, a good coefficient of friction and wear resistance are exhibited, and by setting the median diameter to 100 μm or less, it is possible to avoid the decrease in the thermal conductivity of the friction material.

  In addition, the median diameter of the said magnesium oxide and graphite can be measured using methods, such as a laser diffraction particle size distribution measurement. For example, it can be measured by a laser diffraction / scattering type particle size distribution measuring device, trade name: LA · 920 (manufactured by Horiba, Ltd.). If the effect of the present invention is not impaired, the friction material composition of the present embodiment may be used in combination with an inorganic filler generally used for the friction material other than the magnesium oxide.

  As inorganic fillers other than magnesium oxide, for example, zirconium oxide, antimony trisulfide, tin sulfide, molybdenum disulfide, iron sulfide, bismuth sulfide, zinc sulfide, calcium hydroxide, calcium oxide, calcium oxide, sodium carbonate, calcium carbonate, carbonate Magnesium, barium sulfate, dolomite, coke, graphite, mica, iron oxide, vermiculite, granular potassium titanate, lithium potassium titanate, calcium sulfate, plate-like potassium titanate, talc, clay, zeolite, zirconium silicate, mullite, chromite, Activated aluminas such as titanium oxide, silica and γ-alumina can be used, and these can be used alone or in combination of two or more.

  It is preferable that it is 20-80 mass% in the composition for friction materials including magnesium oxide and graphite, and, as for the total content of the said inorganic filler, it is more preferable that it is 30-80 mass%. It is further preferred that When the content of the inorganic filler is 20 to 80% by mass, the deterioration of the heat resistance can be avoided.

[Fiber base material]
The friction material composition of the present embodiment contains a fibrous base material. The fibrous base material exhibits the reinforcing action in the friction material. As a fiber base material, an organic fiber, a metal fiber, an inorganic fiber etc. are mentioned.

  In the friction material composition of the present embodiment, aramid fibers, acrylic fibers, cellulose fibers, phenol resin fibers and the like can be used as organic fibers, and these can be used alone or in combination of two or more. Among these, it is preferable to use an aramid fiber from the viewpoint of heat resistance and a reinforcing effect.

  As the metal fiber, copper fiber, iron-based fiber, titanium fiber, zinc fiber, aluminum fiber, etc. can be used, and one type or a combination of two or more types can be used, but in the case of using copper fiber, friction material The content of copper as an element in the composition does not exceed 0.5% by mass.

  Moreover, the friction material composition of this embodiment contains 1-3 mass% of iron-type fibers as a metal fiber.

  The iron-based fibers referred to here include pure iron fibers, steel fibers, cast iron fibers, stainless steel fibers, iron-based alloy fibers with silicon and aluminum, and the like. In the present specification, the above-described steel fibers are described as iron fibers.

  By setting the content of the iron-based fibers in the friction material composition to 1% by mass or more, good abrasion resistance and BTV characteristics are exhibited, and by setting the content to 3% by mass or less, the disc rotor which is a mating material is obtained. Aggressiveness, the occurrence of rust on the friction surface can be suppressed. The content of the iron-based fiber is more preferably 1.2 to 3% by mass, and still more preferably 1.4 to 3% by mass.

  Moreover, the shape of the said iron-type raw material is not limited to a fiber shape, Even if it uses in powder form, the same effect can be exhibited.

  As the inorganic fibers, wollastonite, ceramic fibers, biodegradable ceramic fibers, mineral fibers, carbon fibers, glass fibers, potassium titanate fibers, aluminosilicate fibers, etc. can be used, and one or more of them can be used in combination Although it can be used, it is preferable not to contain a suctionable potassium titanate fiber or the like from the viewpoint of environmental friendliness. Moreover, the friction material composition of the present embodiment contains 10 to 30% by mass of wollastonite having a fiber length of 30 μm or less as inorganic fibers.

  By setting the content of the wollastonite in the friction material composition to 10% by mass or more, a good friction coefficient and wear resistance are exhibited, and by setting the content to 30% by mass or less, the porosity and compression of the friction material An increase in the amount of distortion can be avoided. The content of wollastonite is more preferably 10 to 25% by mass, and still more preferably 10 to 20% by mass.

In addition, mineral fiber here is artificial mineral fiber melt-spun mainly with blast furnace slag such as slag wool, basalt such as basalt fiber, other natural rock etc, and it is natural mineral containing Al element Is more preferred. Specifically, those containing SiO ₂ , Al ₂ O ₃ , CaO, MgO, FeO, Na ₂ O, etc., or those containing one or more of these compounds can be used as mineral fibers. Among these, those containing Al element are more preferable. The adhesive strength with each component in the friction composition tends to decrease as the average fiber length of all the mineral fibers contained in the friction material composition increases, so the average fiber length of the entire mineral fibers is preferably 500 μm or less, More preferably, it is 100 to 400 μm. Here, the average fiber length refers to a number average fiber length indicating the average value of the lengths of all the corresponding fibers. For example, with an average fiber length of 200 μm, 50 mineral fibers to be used as a raw material of the friction material composition are randomly selected, the fiber length is measured with an optical microscope, and the average value is 200 μm.

The mineral fiber used in the present embodiment is preferably bio-soluble from the viewpoint of human toxicity. The term "biosoluble mineral fiber" as used herein is a mineral fiber having a characteristic that it is partially decomposed in a short time and taken out of the body even when it is taken into the human body. Specifically, the chemical composition is at least 18% by mass of alkali oxides and alkaline earth oxides (total of sodium, potassium, calcium, magnesium and barium oxides), and in a short-term biopermanence test by respiration, The mass half-life of fibers greater than 20 μm indicates fibers within 40 days or within the peritoneal test and that there is no evidence of excessive carcinogenicity in an intraperitoneal test or that there is no associated pathogenicity or tumorigenesis in a long-term respiratory test (EU directive 97 / 69 / EC Nota Q (oncogenic exclusion excluded)). Such biodegradable mineral fibers include SiO ₂ -Al ₂ O ₃ -CaO-MgO-FeO-Na ₂ O-based fibers and the like, and SiO ₂ , Al ₂ O ₃ , CaO, MgO, FeO, Na Fibers containing ₂ O etc. in any combination may be mentioned. Commercially available products include LAPINUS FIBERS B. V. And Roxul series ("Roxul" is a registered trademark) and the like. “Roxul” includes SiO ₂ , Al ₂ O ₃ , CaO, MgO, FeO, Na ₂ O and the like.

  The content of the fiber base in the friction material composition is preferably 5 to 40% by mass, more preferably 5 to 35% by mass, and still more preferably 10 to 30% by mass. When the content of the fiber base material is 5 to 40% by mass, there is an effect of imparting an appropriate reinforcing effect to the friction material without giving negative effects such as a significant decrease in the effective properties.

[Binder]
The friction material composition of the present embodiment contains a binder. The binder integrates the organic filler and the fiber base contained in the friction material composition to give strength. As a binder contained in the friction material composition of the present embodiment, a thermosetting resin generally used for a friction material can be used. Examples of the thermosetting resin include various modified phenolic resins such as phenolic resin, acrylic modified phenolic resin, silicone modified phenolic resin, cashew modified phenolic resin, epoxy modified phenolic resin, alkylbenzene modified phenolic resin and the like, and in particular, phenolic resin Acrylic modified phenolic resins and silicone modified phenolic resins are preferred, and these can be used alone or in combination of two or more. It is preferable to use a phenol resin, an acrylic modified phenolic resin, a silicone modified phenolic resin, and an alkylbenzene modified phenolic resin in order to give good heat resistance, moldability and friction coefficient.

  The content of the binder in the friction material composition of the present embodiment is preferably 5 to 20% by mass, more preferably 5 to 15% by mass, and further preferably 5 to 10% by mass. preferable. By setting the content of the binder in the range of 5 to 20% by mass, it is possible to further suppress the decrease in strength of the friction material, and to reduce the porosity of the friction material and to increase the modulus of elasticity. Vibration deterioration can be suppressed.

[Organic filler]
The friction material composition of the present embodiment contains an organic filler. The organic filler is included as a friction modifier for improving the sound vibration performance and the wear resistance of the friction material. As the organic filler contained in the composition for a friction material of the present invention, cashew dust, a rubber component and the like can be used.

  The above-mentioned cashew dust may be obtained by pulverizing a product obtained by polymerizing and curing cashew nut shell oil, as long as it is generally used as a friction material.

  Examples of the rubber component include tire rubber, acrylic rubber, isoprene rubber, NBR (nitrile butadiene rubber) and SBR (styrene butadiene rubber), and these are used alone or in combination of two or more.

  Moreover, although cashew dust and a rubber component may be used together and what coated cashew dust with a rubber component may be used, it is preferable to use cashew dust and a rubber component together from a viewpoint of sound vibration performance. . The content of the above-mentioned cashew dust is preferably 2 to 8% by mass, more preferably 2.5 to 8% by mass, and still more preferably 2.5 to 7.5% by mass. By setting the content of the cashew dust to 2 to 8% by mass, it is possible to avoid the deterioration of the sound vibration performance such as the squeal caused by the increase of the elastic modulus of the friction material, and also the heat resistance deterioration and the strength due to the heat history. You can avoid the decline.

  The content of the organic filler in the non-asbestos friction material composition of the present embodiment is preferably 1 to 20% by mass, more preferably 1 to 15% by mass, and 2 to 10% by mass. It is further preferred that By setting the content of the organic filler in the range of 1 to 20% by mass, it is possible to avoid the deterioration of the acoustic vibration performance such as the squeal caused by the increase of the elastic modulus of the friction material, and the deterioration of the heat resistance and the heat. It is possible to avoid the strength reduction due to the history.

[Other ingredients]
In addition to the above-described materials, the friction material composition of the present embodiment can be blended with other materials as needed. For example, metal powder such as zinc powder can be blended.

<Friction material and friction member>
The friction material composition of the present embodiment can be used as a friction material for a disc brake pad, brake lining, etc. of an automobile or the like, or by subjecting the friction material composition of the present embodiment to a desired shape. It can also be used as a friction material for clutch facings, electromagnetic brakes, holding brakes and the like.

The friction material composition of the present embodiment can be used as a friction member itself that becomes a friction surface to obtain a friction material. As a friction material using it, the following composition is mentioned, for example. (1) Configuration of only the friction member (2) Configuration including the back metal and the friction member made of the friction material composition of the present invention which is formed on the back metal and becomes the friction surface (3) Configuration of the above (2) Between the back metal and the friction member, a primer layer for surface modification to enhance the adhesion effect of the back metal, and a configuration further including an adhesive layer for bonding the back metal and the friction member. It can be mentioned.
The above-mentioned back metal is usually used as a friction member in order to improve the mechanical strength of the friction member, and as the material, metal or fiber reinforced plastic can be used. For example, iron, stainless steel, inorganic fiber Reinforced plastics and carbon fiber reinforced plastics may be mentioned. The primer layer and the adhesive layer may be those generally used for friction members such as brake shoes.

  The friction material composition of this embodiment can manufacture a friction material using the method generally used, and can be manufactured by heat-pressing the friction material composition of this invention. Specifically, for example, the friction material composition of the present embodiment is mixed with a Loedige mixer ("Ledige" is a registered trademark), a pressure kneader, an Eirich mixer ("Eich" is a registered trademark), etc. The mixture is uniformly mixed using a molding machine, and the mixture is preformed in a molding die, and the obtained preform is molded under conditions of a molding temperature of 130 to 160 ° C., a molding pressure of 20 to 50 MPa and a molding time of 2 to 10 minutes. The friction material of the present embodiment can be obtained by molding and heat treating the obtained molded product at 150 to 250 ° C. for 2 to 10 hours. In addition, you may perform coating, a scorch process, grinding | polishing process etc. as needed.

The friction material composition of the present embodiment is excellent as the wear resistance at high temperatures, suppression of metal catch and the like, and thus is useful as an "overlaying material" for friction members such as disc brake pads and brake linings. It can also be molded and used as a "underlaying material".
Here, the "overlaying material" is a friction material which is the friction surface of the friction member, and the "underlaying material" is a friction material which is interposed between the friction material which is the friction surface of the friction member and the backing metal. It is a layer for the purpose of improving shear strength and crack resistance in the vicinity of the bonding portion with the back metal.

  Hereinafter, the present invention will be described in more detail by way of examples. The present invention is not limited to these.

<Examples 1 to 7 and Comparative Examples 1 to 7> [Production of Disc Brake Pad]
The materials were compounded according to the compounding ratios shown in Tables 1 and 2 to obtain friction material compositions of Examples 1 to 7 and Comparative Examples 1 to 7. In addition, the unit of the compounding quantity of each component of Table 1 and 2 is the mass% in a friction material composition.

This friction material composition was mixed by a Loedige mixer (made by Matsubo Co., Ltd., trade name: Loedige mixer M20), and this mixture was preformed by a molding press (manufactured by Oji Machine Industry Co., Ltd.). The preform is heated and pressed together with a backing metal (iron) manufactured by Hitachi Automotive Systems, Ltd. using a molding press (manufactured by Sanki Seiko Co., Ltd.) under the conditions of a molding temperature of 45 ° C., a molding pressure of 35 MPa and a molding time of 5 minutes. The resulting molded product is heat-treated at 200 ° C. for 4.5 hours, polished using a rotary polisher, scorked at 500 ° C., and disc brake pad (friction material thickness 9.5 mm, friction Projected area 52 cm ² ) was obtained.

  In addition, the various materials used in the Example and the comparative example are as follows. (Binder)-Phenolic resin: Hitachi Chemical Co., Ltd. (trade name: HP 491UP) (organic filler)-Cashew dust-SBR powder (inorganic filler)-potassium titanate-barium sulfate-Graphite A: median diameter = 8 .5 μm · Graphite B: median diameter = 380.4 μm · antimony trisulfide · calcium hydroxide · zirconium oxide: median diameter = 2.5 μm · magnesium oxide: median diameter = 3.5 μm (fiber base material) · aramid fiber (organic Fiber) · Wollastonite (inorganic fiber) · Copper fiber (metal fiber) · Iron fiber (metal fiber) (Others) · Iron powder

  The disk brake pads of Examples 1 to 7 and Comparative Examples 1 to 7 manufactured by the above-described method were evaluated for various performances using a brake dynamo tester (manufactured by New Japan Special Machine Co., Ltd.). For the experiment, using a general pin-slide collet caliper and a bench-rated disc rotor (FC 250 (grey cast iron)) manufactured by Kiriu Corporation, Nissan Motor Co., Ltd., trade name: Evaluated by the moment of inertia of Skyline V35 Did.

(Evaluation of effectiveness characteristics)
The test conformed to Automobile Engineering Society Standard JASO C406, and the average value of the coefficient of friction in the second efficacy test was calculated and evaluated as an effective characteristic.

(Evaluation of wear resistance)
The test conformed to JASO C 427, and the wear amount of the disk pad at brake temperatures before braking of 100, 200, 300 and 400 ° C. was measured and evaluated as wear resistance.

(Evaluation of BTV characteristics)
First, grinding was performed 200 times at an initial speed of 60 km / h, a final speed of 0 km / h, a deceleration of 0.3 G, and a disc rotor temperature at 130 ° C. at the start of braking. Subsequently, as the main measurement, braking was performed three times under the conditions of an initial speed of 160 km / h, a final speed of 60 km / h, a deceleration of 0.3 G, and a disc rotor temperature of 400 ° C. at the start of braking. Were evaluated as BTV characteristics.

(Evaluation of specific gravity)
The test conformed to Japanese Industrial Standard JIS D4417. The manufactured disk brake pad was broken to remove the back metal, and when it had elements other than the friction member such as an adhesive layer, the friction member obtained by removing by grinding was used. If specific gravity is less than 2.25, it will be A evaluation, if 2.25 or more and less than 2.30, it will be B evaluation and if 2.30 or more, it will be C evaluation.

* The compounding amounts in Tables 1 and 2 are% by mass with respect to the entire friction material composition.

  Examples 1 to 6 are Comparative Example 1 not containing iron fibers, Comparative Example 2 in which the content of iron fibers exceeds 3% by mass, Comparative Example 3 in which the content of wollastonite is less than 10% by mass, magnesium oxide 10% by weight or more and Comparative Example 4 in which the median diameter of graphite is 30 μm or more, Comparative Example 5 in which the content ratio of cashew dust is less than 2% by weight, and the content ratio of both graphite and magnesium oxide is 10 It is clear that the effect characteristics, the abrasion resistance and the BTV characteristics are improved in a well-balanced manner as compared with Comparative Example 6 in which the content is more than% by mass. Moreover, the thermographic image of the disk rotor at the time of BTV evaluation is shown in FIG. Example 1 exhibited stable friction characteristics with a uniform temperature gradient compared to Comparative Example 1. Furthermore, the specific gravity is smaller than that of Comparative Example 7 in which the friction characteristics are relatively good but the copper content is 0.5% by mass or more, and zirconium oxide having a large specific gravity is contained as an abrasive material, and the fuel consumption of the automobile It can contribute to improvement.

  The non-asbestos friction material composition, the friction material and the friction member using the same according to the present invention are environmentally friendly and have good properties because less copper is contained in the wear powder generated during braking as compared with the conventional products. It is suitable for friction materials and friction members such as brake pads for passenger cars and the like because it has wear resistance, BTV characteristics, and further contributes to improvement in fuel efficiency of automobiles and the like because it is lightweight.

Claims (6)

  A friction material composition comprising a binder, an organic filler, an inorganic filler, and a fibrous base material, wherein the copper content as an element does not exceed 0.5% by mass, and iron-based fiber or iron-based powder 1 A friction material composition containing 3% by mass and containing 10 to 30% by mass of wollastonite as a fiber base.   The friction material composition according to claim 1, containing 1 to 10% by mass of magnesium oxide as an inorganic filler.   The friction material composition according to claim 1 or 2, wherein the inorganic filler contains 1 to 10% by mass of graphite, and the median diameter of the graphite is 1 to 30 μm.   The friction material composition according to any one of claims 1 to 3, which contains 2 to 8% by mass of cashew dust as an organic filler.   The friction material formed by shape | molding the friction material composition as described in any one of Claims 1-4.   A friction member formed by integrating the friction material according to claim 5 and a back metal.