WO2019151390A1 - Friction material, friction material composition, friction member, and vehicle - Google Patents

Friction material, friction material composition, friction member, and vehicle Download PDF

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Publication number
WO2019151390A1
WO2019151390A1 PCT/JP2019/003351 JP2019003351W WO2019151390A1 WO 2019151390 A1 WO2019151390 A1 WO 2019151390A1 JP 2019003351 W JP2019003351 W JP 2019003351W WO 2019151390 A1 WO2019151390 A1 WO 2019151390A1
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Prior art keywords
mass
friction material
friction
content
inorganic
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PCT/JP2019/003351
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French (fr)
Japanese (ja)
Inventor
蔵 藤岡
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日立化成株式会社
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Priority to JP2019569546A priority Critical patent/JPWO2019151390A1/en
Publication of WO2019151390A1 publication Critical patent/WO2019151390A1/en

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    • C—CHEMISTRY; METALLURGY
    • C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
    • C09K—MATERIALS FOR MISCELLANEOUS APPLICATIONS, NOT PROVIDED FOR ELSEWHERE
    • C09K3/00—Materials not provided for elsewhere
    • C09K3/14—Anti-slip materials; Abrasives
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
    • F16D—COUPLINGS FOR TRANSMITTING ROTATION; CLUTCHES; BRAKES
    • F16D69/00—Friction linings; Attachment thereof; Selection of coacting friction substances or surfaces
    • F16D69/02—Compositions of linings; Methods of manufacturing

Definitions

  • the present invention relates to a friction material, a friction material composition, a friction member, and a vehicle.
  • friction materials such as disc brake pads and brake linings are used for braking. These friction materials play a role of braking by friction with a disk rotor, a brake drum, or the like which is a counterpart material. For this reason, friction materials not only require an appropriate coefficient of friction (effectiveness characteristics) according to the conditions of use, but also make it difficult for brake noise to occur (squeal characteristics), and the friction material has a long life (wear resistance). Etc. are required.
  • Friction materials include semi-metallic materials containing 30 to 60% by mass of steel fibers as a fiber base material, raw steel materials containing less than 30% by mass of steel fibers, and NAO (Non-Asbestos Organic) materials that do not contain steel fibers. Broadly divided. However, friction materials containing a small amount of steel fibers may be classified as NAO materials.
  • NAO material does not contain steel fibers, it has a feature that it is less aggressive to the disk rotor as the counterpart material than semi-metallic material and low steel material. Because of these advantages, NAO materials that are effective in Japan, the United States, etc., and have a good balance between squealing and wear resistance, are currently mainstream. On the other hand, in Europe, low steel materials were often used from the viewpoint of maintaining a friction coefficient during high-speed braking, but in recent years, NAO materials are less prone to tire wheel dirt and brake noise in order to respond to a higher-grade market. Are increasingly being used.
  • the NAO material generally contains copper in a powder or fiber state.
  • friction materials containing copper, copper alloys, and the like contain copper in wear powder generated during braking, and thus have been suggested to possibly contaminate rivers, lakes, and the like. For this reason, in California, Washington, etc. in the United States, there is a bill that prohibits the sale of friction materials containing more than 5% by mass of copper after 2021, and the addition of 0.5% by mass of copper after 2023, and the assembly into new cars. In response to this, there is an urgent need to develop a NAO material that does not contain copper or has a low copper content.
  • One of the typical functions of copper is to impart thermal conductivity. Since copper has high thermal conductivity, wear caused by excessive temperature rise is suppressed by diffusing heat generated during braking from the friction interface.
  • the second typical function of copper is protection of the friction interface during high-temperature braking. Since copper has high ductility and malleability, it extends to the friction material surface by braking to form a coating. As a result, it is possible to reduce friction material wear during high-speed and high-temperature braking and to develop a stable friction coefficient. Further, since the copper spreading film can easily hold the abrasive, a good friction coefficient can be expressed even in the low-speed and low-temperature braking region. Therefore, in order to develop a NAO material that does not contain copper or has a low copper content, a copper replacement technique is required from the viewpoints of improving the thermal conductivity, protecting the interface, and holding the abrasive. .
  • Patent Documents 1 and 2 In such a movement, friction materials that do not contain copper or have a low copper content are being studied (for example, Patent Documents 1 and 2).
  • JP2015-205959A Japanese Patent Laying-Open No. 2015-059125
  • a typical example of the friction coefficient variation is a decrease in the friction coefficient in a low-speed and low-temperature braking region in a friction material that does not contain copper.
  • the friction material not containing copper it is difficult to form a transfer film on the surface of the disk rotor in the low-speed and low-temperature braking region, and it is difficult to exhibit the effect of holding the abrasive.
  • the aggressiveness to the disk rotor due to the grinding action and the shear drag generated between the iron component derived from the disk rotor and the disk rotor are reduced, so that the friction coefficient tends to be lower than in the normal case.
  • the braking distance becomes long and the braking force is reduced, so that the driver's comfort is impaired.
  • an increase in the coefficient of friction variation during one braking in low-speed low-temperature braking is a typical example in which the coefficient of friction varies.
  • the friction material containing no copper has a low ability to discharge wear powder generated during braking, and the wear powder tends to accumulate at the friction interface between the friction material and the disk rotor.
  • the powder resistance at the friction interface is increased, and the coefficient of variation of the friction coefficient is increased.
  • problems such as squealing occur when the brake is applied and the driver's comfort is impaired.
  • the ratio of braking force obtained by friction is reduced, that is, the braking load is reduced, as compared with a conventional hydraulic brake. For this reason, it is difficult to remove the rust generated on the surface of the rotor, and adhesion due to rust occurs between the rotor and the brake pad, and the friction material may be separated at the start. Therefore, in order to improve the adaptability to the regenerative brake, it is required to provide the brake pad with a performance capable of removing rust generated on the rotor surface.
  • Patent Documents 1 and 2 focus only on the high thermal conductivity and high-temperature lubricity of copper, and only complement the friction characteristics during high-speed and high-temperature braking. Therefore, the stability of the friction coefficient in the low-speed low-temperature braking region, the rust removal property, and other friction characteristics are not considered.
  • the present invention does not contain copper, or even if it contains copper, the content thereof is 0.5% by mass or less as a copper element, and the composition is low in environmental and human harm, and is excellent in a low-speed low-temperature braking region.
  • An object of the present invention is to provide a friction material, a friction material composition, a friction member using the friction material, and a vehicle that have both the stability of the friction coefficient and the excellent friction coefficient in the normal braking range and are excellent in rust removal. .
  • the present inventor has found that a friction material containing inorganic fibers containing a specific amount of shots has excellent friction coefficient stability in a low-speed low-temperature braking region, and usually The present inventors have found that the excellent friction coefficient in the braking region is compatible and the rust removing property is excellent. That is, the present invention relates to the following [1] to [20].
  • the total content of the inorganic fibers (X1) and the shot (X2) is 1.0% by mass or more and less than 10.0% by mass with respect to 100% by mass of the total amount of the friction material.
  • the content of the shot (X2) is 0.2 to 10% by mass in the total amount of the inorganic fibers (X1) and the shot (X2), according to any one of the above [1] to [3] Friction material.
  • the above [1] to [5] further comprising 4 to 10% by mass of zirconium silicate having an average particle diameter of 0.4 to 2 ⁇ m as an inorganic filler with respect to 100% by mass of the total friction material.
  • the above [1] further contains 15 to 25% by mass of a non-acicular titanate having an average particle diameter of 2 to 50 ⁇ m as an inorganic filler with respect to 100% by mass of the total friction material.
  • a non-acicular titanate having an average particle diameter of 2 to 50 ⁇ m as an inorganic filler with respect to 100% by mass of the total friction material.
  • To [6]. [8] The friction material according to any one of [1] to [7], further comprising 10 to 20% by mass of zirconium oxide as an inorganic filler with respect to 100% by mass of the total friction material.
  • a friction member obtained by integrating the friction material according to any one of [1] to [9] and a back metal.
  • a friction material composition that does not contain copper or contains copper, and the content thereof is 0.5% by mass or less as a copper element, and shots of inorganic fibers (X1) and inorganic fibers (X1) ( X2), and the content of the shot (X2) is 0.2% by mass or more in the total amount of the inorganic fibers (X1) and the shot (X2).
  • copper does not contain, or even if contained, the content is 0.5% by mass or less as a copper element, and the composition is low in environmental and human harm, and is excellent in a low-speed low-temperature braking region. It is possible to provide a friction material, a friction material composition, a friction member using the friction material, and a vehicle that have both the stability of the friction coefficient and the excellent friction coefficient in the normal braking range and are excellent in rust removal.
  • the friction material, friction material composition, and friction member of this embodiment are explained in full detail, this invention is not limited to the following embodiment.
  • the friction material and friction material composition of this embodiment do not contain asbestos, and are a so-called non-asbestos friction material and non-asbestos friction material composition.
  • the friction material which concerns on this embodiment is a friction material which is 0.5 mass% or less as a copper element even if it does not contain copper or contains copper, and inorganic fiber (X1) and this inorganic fiber (X1) ) Shot (X2), and the content of the shot (X2) is 0.2% by mass or more in the total amount of the inorganic fibers (X1) and the shot (X2).
  • the friction material of this embodiment does not contain copper, the content is 0.5 mass% or less as a copper element, and is very trace amount. For this reason, the friction material of this embodiment becomes a thing with a low environmental hazard and a human body hazard.
  • said "copper” is copper element contained in copper, such as a fiber form and a powder form; copper alloy, a copper compound, etc.
  • "copper content” is content with respect to 100 mass% of friction material whole quantity. Show.
  • the copper content is preferably less than 0.5% by mass, more preferably 0.3% by mass or less, and more preferably 0.1% by mass with respect to 100% by mass of the total amount of the friction material, from the viewpoints of environmental hazards and human injury. % Or less is more preferable, and it is particularly preferable not to contain copper.
  • the friction material of this embodiment contains 1 or more types selected from the group which consists of a fiber base material, an inorganic filler, an organic filler, and a binder.
  • the friction material of this embodiment contains 1 or more types selected from the group which consists of a fiber base material, an inorganic filler, an organic filler, and a binder.
  • the friction material which concerns on this embodiment contains an inorganic fiber as a fiber base material.
  • Inorganic fiber is a component that not only reinforces the friction material in the form of fibers, but also allows adjustment of friction characteristics such as friction coefficient and rotor aggression by selecting various material characteristics such as composition, fiber length, and toughness. is there.
  • the friction material according to the present embodiment includes the inorganic fiber (X1) and the shot (X2) of the inorganic fiber (X1), and the content of the shot (X2) is the inorganic fiber (X1) and the shot (X2). ) In the total amount of 0.2).
  • the friction material of the present embodiment is excellent in rust removing properties when the content of the shot (X2) is 0.2% by mass or more in the total amount of the inorganic fibers (X1) and the shot (X2). .
  • shot refers to non-fibrous particles that cannot remain as fibers and remain in the form of particles in the production process of inorganic fibers, and have a particle diameter of 125 ⁇ m or more.
  • the “shot particle diameter” means the long diameter of the particle in the particle projection image, and can be measured using, for example, a scanning electron microscope (SEM).
  • the inorganic fiber (X1) is not particularly limited, but is preferably a mineral fiber.
  • the mineral fiber referred to here is a man-made inorganic fiber that is melt-spun mainly composed of blast furnace slag such as slag wool, basalt such as basalt fiber; and other natural rocks, and is a natural mineral containing Al element. Is more preferable.
  • a material containing SiO 2 , Al 2 O 3 , CaO, MgO, Fe 2 O 3 , Na 2 O, or the like can be used as the mineral fiber.
  • the inorganic fiber (X1) is preferably an inorganic fiber having biosolubility.
  • the term “inorganic fiber having biosolubility” as used herein means that it is characterized in that even when it is taken into the human body, it is partially decomposed in a short time and discharged outside the body, and examples thereof include biosoluble mineral fibers. .
  • the chemical composition is alkali oxide, alkaline earth oxide total amount (total amount of oxides of sodium, potassium, calcium, magnesium, barium) is 18% by mass or more, and in a short-term biopermanent test by respiration, Inorganic fibers satisfying a mass half-life of fibers of 20 ⁇ m or more within 40 days, or no evidence of excessive carcinogenicity in intraperitoneal tests, or related pathogenicity and tumor development in long-term respiratory tests (EU Directive 97/69 / EC NotaQ (exclusion of carcinogenicity)).
  • inorganic fibers (X1) SiO 2 -Al 2 O 3 -CaO-MgO-Fe 2 O 3 -Na 2 O -based fibers and the like, SiO 2, Al 2 O 3 , CaO, MgO, Examples thereof include fibers containing Fe 2 O 3 , Na 2 O and the like in any combination.
  • the inorganic fiber (X1) is preferably an inorganic fiber containing calcium oxide (hereinafter also referred to as “CaO”) and magnesium oxide (hereinafter also referred to as “MgO”).
  • the “inorganic fiber containing CaO and MgO” means an inorganic fiber containing CaO and MgO as components constituting one fiber, and the same applies to each component other than CaO and MgO described later. It is.
  • content of each component in the following inorganic fiber (X1) is content based on 100 mass% of inorganic fiber (X1) whole quantity.
  • the CaO content in the inorganic fibers (X1) is preferably 15 to 30% by mass, more preferably 17 to 25% by mass, and further preferably 18 to 22% by mass.
  • the content of MgO in the inorganic fiber (X1) is preferably 3 to 20% by mass, more preferably 4 to 15% by mass, and further preferably 5 to 8% by mass.
  • the total content of CaO and MgO in the inorganic fiber (X1) is preferably 18 to 40% by mass, more preferably 22 to 35% by mass, and further preferably 25 to 30% by mass.
  • the inorganic fiber (X1) may contain other oxides other than CaO and MgO. Other oxides, SiO 2, Al 2 O 3 , Na 2 O, K 2 O, TiO 2, P 2 O 5, MnO, Fe 2 O 3, SrO, ZrO 2 and the like. Among these, it preferably contains SiO 2, Al 2 O 3, Fe 2 O 3.
  • Inorganic fibers (X1) is, when it contains one or more selected from the group consisting of SiO 2, Al 2 O 3 and Fe 2 O 3, the content in the inorganic fibers (X1) in are as follows .
  • the content of SiO 2 is preferably 10 to 60% by mass, more preferably 30 to 50% by mass, further preferably 35 to 47% by mass, and particularly preferably 40 to 45% by mass.
  • the content of Al 2 O 3 is preferably 1 to 35% by mass, more preferably 5 to 32% by mass, further preferably 10 to 30% by mass, still more preferably 13 to 25% by mass, and 15 to 20% by mass. Is particularly preferred.
  • the content of Fe 2 O 3 is preferably 1 to 10% by mass, more preferably 2 to 9% by mass, and further preferably 4 to 8% by mass.
  • the total content of CaO, MgO, SiO 2 , Al 2 O 3 and Fe 2 O 3 in the inorganic fiber (X1) is preferably 90% by mass or more, more preferably 93% by mass or more, and further more preferably 95% by mass or more. preferable. Further, the total content may be 100% by mass or less, 98% by mass or less, or 97% by mass or less.
  • the inorganic fiber (X1) further contains one or more selected from the group consisting of Na 2 O, K 2 O, TiO 2 , P 2 O 5 and MnO
  • its inclusion in the inorganic fiber (X1) The amounts are as follows.
  • the content of Na 2 O is preferably 1 to 5% by mass, more preferably 1.5 to 4% by mass, and still more preferably 2 to 3% by mass.
  • the content of K 2 O is preferably 0.1 to 1.5% by mass, more preferably 0.2 to 1.2% by mass, and further preferably 0.4 to 0.8% by mass.
  • the content of TiO 2 is preferably 0.2 to 3% by mass, more preferably 0.7 to 2% by mass, and further preferably 1 to 1.5% by mass.
  • the content of P 2 O 5 is preferably 0.01 to 1% by mass, more preferably 0.1 to 0.5% by mass, and further preferably 0.15 to 0.3% by mass.
  • the content of MnO is preferably 0.01 to 1% by mass, more preferably 0.05 to 0.5% by mass, and further preferably 0.07 to 0.2% by mass.
  • the total content of one or more selected from the group consisting of Na 2 O, K 2 O, TiO 2 , P 2 O 5 and MnO in the inorganic fiber (X1) is preferably 0.5 to 10% by mass, It is more preferably 2 to 7% by mass, and further preferably 3 to 5% by mass.
  • the content of SrO in the inorganic fiber (X1) is preferably less than 0.1% by mass, more preferably less than 0.01% by mass, from the viewpoint of rust removal and stability of the coefficient of friction in the low-speed and low-temperature braking region. . Moreover, it is more preferable that inorganic fiber (X1) does not contain SrO from the same viewpoint.
  • the content of ZrO 2 in the inorganic fiber (X1) is preferably less than 0.1% by mass and more preferably less than 0.01% by mass from the viewpoint of rust removal and stability of the coefficient of friction in the low-speed low-temperature braking region. preferable. Moreover, it is more preferable that inorganic fiber (X1) does not contain ZrO 2 from the same viewpoint.
  • the contents of CaO, MgO and other oxides in the inorganic fiber (X1) can be measured by fluorescent X-ray analysis. Moreover, content of the said oxide can be made into content of each oxide converted from content of atoms other than oxygen which forms an oxide.
  • the average fiber length of the inorganic fibers (X1) is preferably 100 to 800 ⁇ m, more preferably 140 to 500 ⁇ m, and further preferably 170 to 300 ⁇ m. When the average fiber length is in the above range, the stability of the friction coefficient can be enhanced without causing adverse effects such as a significant increase in rotor attack.
  • the average fiber diameter of the inorganic fibers (X1) is preferably 1 to 10 ⁇ m, more preferably 2 to 8 ⁇ m, and even more preferably 3 to 6 ⁇ m. When the average fiber diameter is in the above range, the stability of the friction coefficient can be improved without causing adverse effects such as a significant increase in rotor attack.
  • the average fiber length and the average fiber diameter mean a number average fiber length or a number average fiber diameter indicating an average value of the length or diameter of the corresponding fiber.
  • the average fiber length of 200 ⁇ m indicates that 50 fibers 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 ⁇ m.
  • the friction material of the present embodiment contains the inorganic fiber (X1) and the shot (X2) generated in the manufacturing process of the inorganic fiber (X1). Therefore, the shot (X2) has the same material as the inorganic fiber (X1).
  • the shot (X2) is mixed in the inorganic fiber (X1) used as a raw material. Therefore, in the process of manufacturing the friction material, the inorganic fiber (X1) and the shot (X2) are usually used.
  • the shot (X2) isolated from the inorganic fiber (X1) may be blended separately from the inorganic fiber (X1).
  • the average particle size of the shot (X2) is preferably 125 to 300 ⁇ m, more preferably 125 to 200 ⁇ m, and further preferably 125 to 150 ⁇ m from the viewpoint of rust removal.
  • the average particle diameter of the shot (X2) can be obtained as an average value by measuring the particle diameter of any 50 shots using, for example, a scanning electron microscope (SEM).
  • SEM scanning electron microscope
  • the content of the shot (X2) is 0.2% by mass or more, preferably 0.2 to 20% by mass in the total amount of the inorganic fibers (X1) and the shot (X2) from the viewpoint of rust removing property, and is preferably 0.2 to 20% by mass. 2 to 15% by mass is more preferable, 0.2 to 12% by mass is further preferable, 0.2 to 10% by mass is further more preferable, 0.2 to 8% by mass is further more preferable, and 0.2 to 6% by mass. % Is particularly preferable, and 0.2 to 5% by mass is most preferable.
  • the content of the shot (X2) in the friction material of this embodiment is preferably 0.001 to 2% by mass, more preferably 0.002 to 1% by mass with respect to 100% by mass of the total amount of the friction material. 003 to 0.75% by mass is more preferable, 0.005 to 0.5% by mass is more preferable, 0.007 to 0.3% by mass is particularly preferable, and 0.01 to 0.25% by mass is most preferable.
  • the total content of inorganic fibers (X1) and shots (X2) in the friction material of the present embodiment is 1.0% by mass or more and less than 10.0% by mass with respect to 100% by mass of the total friction material. preferable.
  • the total content is within the above range, high friction coefficient stability is obtained in the low-speed and low-temperature braking range, the coefficient of friction variation during one braking is reduced, and an excellent friction coefficient is obtained in the normal braking range.
  • the content of the inorganic fiber (X) is 1.0% by mass or more, the coefficient of friction variation during one braking can be reduced while ensuring the coefficient of friction stability in the low-speed and low-temperature braking region.
  • the friction coefficient stability in the low-speed and low-temperature braking region is improved while the friction coefficient variation rate during one braking is secured.
  • the total content of inorganic fibers (X1) and shots (X2) in the friction material of the present embodiment is more preferably 2.0 to 9.9% by mass with respect to 100% by mass of the total friction material. It is preferably 4.0 to 8% by mass, more preferably 5.0 to 7% by mass.
  • the friction material of this embodiment contains 1 or more types selected from the group which consists of organic fiber, another inorganic fiber, and metal fiber besides inorganic fiber (X1). These fiber base materials exhibit a reinforcing action in the friction material.
  • organic fiber, other inorganic fiber, and metal fiber may be used individually by 1 type, respectively, and may use 2 or more types together.
  • the friction material of this embodiment does not contain the metal fiber from the viewpoint of not excessively increasing the aggressiveness to the disk rotor which is the counterpart material, or the content thereof is 100% by mass of the total friction material. The content is preferably 0.5% by mass or less.
  • organic fibers examples include aramid fibers, acrylic fibers, and cellulose fibers. Among these, an aramid fiber is preferable from the viewpoints of heat resistance, a reinforcing effect, and appropriate provision of voids.
  • the aramid fiber can use the well-known thing currently used for the friction material.
  • the average fiber length of the organic fibers is, for example, 650 to 1500 ⁇ m, and preferably 1000 to 1300 ⁇ m. The method for measuring the average fiber length is the same as described above.
  • the friction material of the present embodiment contains organic fibers, the total content is preferably 0.5 to 10% by mass, more preferably 1 to 5% by mass with respect to 100% by mass of the total friction material. More preferably, it is 4% by mass.
  • inorganic fibers examples include ceramic fibers, biodegradable ceramic fibers, mineral fibers, carbon fibers, glass fibers, and potassium titanate fibers.
  • ceramic fiber and carbon fiber from the viewpoint of toughness of the inorganic fiber.
  • the friction material of this embodiment may not contain other inorganic fibers according to the desired performance.
  • metal fiber is not included in the definition of inorganic fiber.
  • the total content of the fiber base material in the friction material of the present embodiment is preferably 6 to 20% by mass, more preferably 7 to 17% by mass, and 8 to 15% by mass with respect to 100% by mass of the total friction material. Further preferred. When the total content of the fiber base is within the above range, higher friction coefficient stability is obtained in the low-speed and low-temperature braking region and the normal braking region.
  • the friction material of the present embodiment preferably contains an inorganic filler.
  • the inorganic filler include titanate, wollastonite, metal powder, graphite, various oxides used as an abrasive, and other inorganic fillers.
  • An inorganic filler may be used individually by 1 type, and may use 2 or more types together.
  • the metal powder include iron powder, tin powder, zinc powder, aluminum powder, and alloy powder thereof.
  • the friction material of the present embodiment does not contain metal powder from the viewpoint of not excessively increasing the aggressiveness to the disk rotor as the counterpart material, or the content thereof is 100% by mass of the total friction material. Is less than 0.5% by mass, more preferably less than 0.1% by mass, and even more preferably less than 0.01% by mass.
  • titanate The friction material of this embodiment preferably contains titanate as an inorganic filler. Since titanate has a low Mohs hardness of about 4 and a relatively high melting point of 1000 ° C. or higher, an increase in wear of the friction material can be reduced by interposing at the friction interface during high-speed high-temperature braking.
  • titanates include 6 potassium titanate, 8 potassium titanate, lithium potassium titanate, magnesium potassium titanate, and sodium titanate. Of these, potassium hexatitanate and potassium potassium titanate are preferable from the viewpoint of the stability of the friction coefficient in the low-speed low-temperature braking region.
  • One titanate may be used alone, or two or more may be used in combination. From the viewpoint of wear resistance during high-speed high-temperature braking, one type of titanate may be used alone. preferable.
  • the titanate is preferably not acicular from the viewpoint of human harm. That is, it is preferable that the friction material of this embodiment contains non-acicular titanate.
  • a non-acicular titanate means a plate-like titanate having a polygonal shape, a circle shape, an ellipse shape, or the like, or an indefinite shape titanate.
  • the average particle size of titanate is preferably 2 to 50 ⁇ m, more preferably 2.2 to 40 ⁇ m, and even more preferably 2.5 to 30 ⁇ m.
  • the average particle diameter in the present specification means the median diameter (D 50 ) unless otherwise specified, and can be measured using a method such as laser diffraction particle size distribution measurement.
  • a laser diffraction / scattering particle size distribution measuring device trade name: LA-920 (manufactured by Horiba, Ltd.) can be used. Moreover, it can also measure by sieve classification represented by JISB4130.
  • the content thereof is preferably 15 to 25% by mass, more preferably 15 to 22% by mass, and more preferably 15 to 20% with respect to 100% by mass of the total friction material. More preferred is mass%.
  • the titanate content is equal to or higher than the above lower limit value, excellent wear resistance during high-speed high-temperature braking is obtained, and a sufficient friction coefficient retention effect is obtained. It is possible to suppress a decrease in the friction coefficient.
  • non-acicular titanate having an average particle diameter of 2 to 50 ⁇ m is 15 to 25 mass with respect to 100 mass% of the total friction material. % Content is particularly preferable.
  • Wollastonite is a silicate mineral represented by CaSiO 3 and has, for example, a needle shape or a long column shape.
  • the average aspect ratio (average length / average diameter or thickness) of wollastonite is preferably 3 or more, more preferably 4 to 12, and still more preferably 5 to 8. When the average aspect ratio is 3 or more, the shear strength and crack resistance of the friction material at normal temperature and high temperature can be effectively improved.
  • the average aspect ratio refers to D 50 value (cumulative median of the volume distribution), for example, it can be measured by a dynamic image analysis method.
  • the average length of wollastonite is preferably 100 to 500 ⁇ m, more preferably 150 to 450 ⁇ m, and even more preferably 200 to 400 ⁇ m from the viewpoint of imparting strength to the friction material.
  • the content thereof is preferably 2 to 10% by mass, more preferably 3 to 8% by mass with respect to 100% by mass of the total friction material, and 4 to 7 More preferred is mass%.
  • the friction material of this embodiment may contain zirconium silicate, triiron tetraoxide, triiron dioxide, bismuth oxide, zirconium oxide, or the like as an abrasive. Among these, zirconium silicate and zirconium oxide are preferable.
  • Zirconium silicate has a high Mohs hardness of 6 to 7.5 and is effective in developing a friction coefficient by grinding.
  • the average particle size of zirconium silicate is preferably 0.2 to 2 ⁇ m, more preferably 0.3 to 2 ⁇ m, and further preferably 0.4 to 2 ⁇ m.
  • the content thereof is preferably 4 to 10% by mass and more preferably 5 to 10% by mass with respect to 100% by mass of the total friction material.
  • the friction material of this embodiment may contain 4 to 10% by mass of zirconium silicate having an average particle size of 0.4 to 2 ⁇ m with respect to 100% by mass of the total friction material. Particularly preferred.
  • the friction material of this embodiment may not contain a zirconium silicate according to the desired performance.
  • the average particle diameter of zirconium oxide is preferably 1 to 14 ⁇ m, more preferably 5 to 10 ⁇ m, and still more preferably 8 to 9 ⁇ m.
  • the content thereof is preferably 10 to 20% by mass, more preferably 12 to 19% by mass, and more preferably 14 to 18% by mass with respect to 100% by mass of the total friction material. % Is more preferable.
  • the content of zirconium oxide is not less than the above lower limit value, it has excellent wear resistance during high-speed high-temperature braking, and a sufficient friction coefficient retention effect is obtained. A decrease in coefficient can be suppressed.
  • the friction material of the present embodiment preferably contains graphite. By containing graphite, excellent thermal conductivity can be imparted to the friction material.
  • the average particle diameter of graphite is preferably 100 to 600 ⁇ m, more preferably 200 to 450 ⁇ m, and further preferably 300 to 350 ⁇ m.
  • the average particle diameter of graphite may be 10 to 90 ⁇ m or 20 to 60 ⁇ m depending on the desired thermal conductivity. Two or more types of graphite having different average particle sizes may be used in combination. For example, graphite (I) having an average particle size of 100 to 600 ⁇ m, preferably 200 to 450 ⁇ m, and an average particle size of 10 to 90 ⁇ m.
  • graphite (II) preferably 20 to 60 ⁇ m, may be used in a mass ratio (graphite (I) / graphite (II)) of 0.5 to 5, preferably 1 to 2.
  • the total content is preferably 0.5 to 10% by mass, more preferably 1 to 5% by mass, and more preferably 2 to More preferably, 4% by mass.
  • the average particle diameter and the total content of graphite are within the above ranges, it is possible to achieve both good thermal conductivity imparting to the friction material and retention of the friction coefficient.
  • inorganic fillers include magnesium oxide, antimony trisulfide, zirconium hydroxide, tin sulfide, molybdenum disulfide, bismuth sulfide, zinc sulfide, iron sulfide, calcium hydroxide, calcium oxide, sodium carbonate, calcium carbonate, magnesium carbonate , Barium sulfate, coke, ⁇ alumina, ⁇ alumina, mica, vermiculite, calcium sulfate, mullite, chromite, titanium oxide, silica and the like.
  • antimony trisulfide, tin sulfide, mica, calcium hydroxide, and barium sulfate are preferable.
  • general materials used for friction materials can be used.
  • the content thereof is preferably 0.5 to 5% by mass and more preferably 1.5 to 3% by mass with respect to 100% by mass of the total friction material.
  • the average particle diameter of tin sulfide is preferably 100 to 800 ⁇ m, more preferably 200 to 700 ⁇ m, and further preferably 250 to 650 ⁇ m.
  • the content thereof is preferably 0.2 to 4% by mass and more preferably 1.0 to 2% by mass with respect to 100% by mass of the total amount of the friction material. .
  • the average particle size of antimony trisulfide is preferably 10 to 300 ⁇ m, more preferably 20 to 200 ⁇ m, and even more preferably 30 to 170 ⁇ m.
  • the content is preferably 1 to 10% by mass and more preferably 3 to 7% by mass with respect to 100% by mass of the total friction material.
  • the average particle diameter of mica is preferably 5 to 100 ⁇ m, more preferably 10 to 60 ⁇ m, and further preferably 12 to 20 ⁇ m.
  • the friction material of this embodiment contains calcium hydroxide, the content thereof is preferably 0.01 to 1% by mass, and 0.05 to 0.3% by mass with respect to 100% by mass of the total friction material. More preferred.
  • the average particle size of calcium hydroxide is preferably 10 to 300 ⁇ m, more preferably 30 to 200 ⁇ m, and still more preferably 50 to 100 ⁇ m.
  • the content thereof is preferably 5 to 20% by mass and more preferably 8 to 12% by mass with respect to 100% by mass of the total friction material.
  • the average particle diameter of barium sulfate is preferably 1 to 50 ⁇ m, more preferably 3 to 30 ⁇ m, and even more preferably 5 to 20 ⁇ m.
  • the total content thereof is preferably 12 to 50% by mass, more preferably 15 to 40% by mass with respect to 100% by mass of the total friction material. 20 to 35% by mass is more preferable.
  • the total content of the inorganic filler in the friction material of the present embodiment is preferably 50 to 85% by mass, more preferably 60 to 80% by mass, and 65 to 75% by mass with respect to 100% by mass of the total friction material. Further preferred.
  • the friction material of the present embodiment preferably contains an organic filler.
  • the organic filler is included as a friction modifier for improving the sound vibration performance, wear resistance and the like of the friction material.
  • An organic filler may be used individually by 1 type, and may use 2 or more types together.
  • Examples of the organic filler include cashew dust and rubber components.
  • cashew dust for example, any cashew dust can be used as long as it is usually used for a friction material obtained by pulverizing and curing cashew nut shell oil.
  • the cashew dust is preferably unmodified cashew dust.
  • the average particle size of cashew dust is preferably 50 to 600 ⁇ m, more preferably 70 to 550 ⁇ m, and still more preferably 100 to 500 ⁇ m.
  • the content thereof is preferably 4 to 20% by mass, more preferably 8 to 16% by mass with respect to 100% by mass of the total friction material, and 10 to 14% by mass. % Is more preferable.
  • the content of cashew dust is in the above range, sound vibration performance such as squealing due to low elasticity of the friction material can be improved.
  • the rubber component known materials used for friction materials can be used, and examples thereof include tire rubber, acrylic rubber, isoprene rubber, NBR (nitrile butadiene rubber), SBR (styrene butadiene rubber) and the like.
  • the content thereof is preferably 0.2 to 10% by mass, more preferably 0.5 to 5% by mass, with respect to 100% by mass of the total friction material. It is more preferably 1 to 3% by mass.
  • the friction material of the present embodiment preferably contains one or more selected from the group consisting of cashew dust and a rubber component, and more preferably used in combination with cashew dust and a rubber component.
  • the cashew dust coated with the rubber component may be used. From the viewpoint of sound vibration performance, the cashew dust and the rubber component may be blended separately. Good.
  • the total content is preferably 2 to 20% by mass, more preferably 5 to 17% by mass, and more preferably 10 to 10% by mass with respect to 100% by mass of the total friction material. 15 mass% is further more preferable.
  • the total content of the organic filler is within the above range, sound vibration performance such as squealing due to low elasticity of the friction material is improved, and deterioration in heat resistance and strength reduction due to thermal history can be avoided.
  • the friction material of this embodiment preferably further contains a binder.
  • the binding material provides strength by integrating an organic filler, a fiber base material, and the like contained in the friction material.
  • a binder may be used individually by 1 type and may be used in combination of 2 or more type.
  • a thermosetting resin usually used for a friction material can be used.
  • the thermosetting resin include various modified phenol resins such as phenol resin, acrylic rubber-modified phenol resin, silicone-modified phenol resin, cashew-modified phenol resin, epoxy-modified phenol resin, and alkylbenzene-modified phenol resin.
  • a silicone-modified phenol resin is preferable from the viewpoint of improving the water repellency at the friction interface.
  • the silicone-modified phenol resin a phenol resin in which silicone oil or silicone rubber is dispersed is preferable.
  • the silicone-modified phenol resin may be used alone, but may be used in combination with a thermosetting resin other than the above-described silicone-modified phenol resin, and is preferably used in combination with an acrylic rubber-modified phenol resin.
  • the content ratio [silicone-modified phenol resin: acrylic rubber-modified phenol resin] is preferably 20:80 to 80:20, and preferably 30: 70 to 70:30 is more preferable, and 40:60 to 60:40 is even more preferable.
  • the total content of the binder in the friction material of the present embodiment is preferably 4 to 14% by mass, more preferably 6 to 12% by mass, and further more preferably 8 to 10% by mass with respect to 100% by mass of the total friction material. preferable.
  • the strength of the friction material can be further prevented from lowering, and the porosity of the friction material is reduced and the deterioration of sound vibration performance such as squeal due to the increased elastic modulus is suppressed. it can.
  • the friction material of the present embodiment may contain other materials other than the above components as necessary.
  • the friction material of this embodiment can be manufactured by a generally used method.
  • a manufacturing method of the friction material of this embodiment the method of heat-pressing and manufacturing the friction material composition which satisfies the composition of the friction material of this embodiment is mentioned, for example.
  • the friction material composition of the present embodiment to be described later is uniformly mixed using a mixer such as a Laedige (registered trademark) mixer, a pressure kneader, an Eirich (registered trademark) mixer, and the mixture is mixed.
  • Preliminary molding is performed with a molding die, and the obtained preform is molded under conditions of a molding temperature of 140 to 150 ° C., a molding pressure of 30 to 45 MPa, and a molding time of 3 to 6 minutes.
  • a heat treatment method at 3 ° C. for 3 to 4 hours can be mentioned.
  • the friction material of this embodiment is used in the following aspects (1) to (3), for example.
  • Friction material only configuration Friction member having a back metal and the friction material of the present embodiment to be a friction surface formed on the back metal (3)
  • the back metal A structure in which a primer layer for the purpose of surface modification for enhancing the adhesion effect of the backing metal and an adhesive layer for the purpose of bonding the backing metal and the friction member are further interposed between the friction member and the friction member.
  • the backing metal is used to improve the mechanical strength of the friction member. Examples of the material include metals such as iron and stainless steel; fiber reinforced plastics such as inorganic fiber reinforced plastics and carbon fiber reinforced plastics. .
  • the primer layer and the adhesive layer may be those used for friction members such as brake shoes.
  • the friction material of this embodiment is suitable as a friction material for disc brake pads and brake linings for automobiles.
  • the friction material of this embodiment can be used also as friction materials, such as a clutch facing, an electromagnetic brake, a holding brake, by giving processes, such as a shaping
  • the friction material of this embodiment is suitable for a brake pad for a passenger car mounted on a control brake such as a regenerative brake because it can exhibit a stable friction coefficient in a low-speed low-temperature braking region. That is, according to the present invention, it is possible to provide a passenger vehicle such as an electric vehicle or a hybrid vehicle equipped with a control brake using the friction material of the present embodiment.
  • the friction material of the present embodiment is excellent in stability of friction coefficient, wear resistance at high temperature, etc., it is useful as a “upholstery material” for friction members such as disc brake pads and brake linings. It can also be molded and used as a “underlaying material” for the member.
  • the “upper material” is a friction material that becomes the friction surface of the friction member
  • the “underlay material” is a friction material that is interposed between the friction material that becomes the friction surface of the friction member and the back metal. It is a layer for the purpose of improving the shear strength and crack resistance in the vicinity of the adhesion part with the back metal.
  • the friction material composition according to the present embodiment does not contain copper, or even if it contains copper, the content of the friction material composition is 0.5 mass% or less as a copper element, and the inorganic fiber (X1) and the Friction material which contains shot (X2) of inorganic fiber (X1), and content of said shot (X2) is 0.2 mass% or more in the total amount of inorganic fiber (X1) and shot (X2) It is a composition.
  • the kind of each component contained in the friction material composition of this embodiment, and its manufacturing method are demonstrated similarly to the friction material of the said embodiment, The suitable aspect is altogether the same.
  • the preferable range of the content of each component in the friction material composition is the same as the preferable range described in the friction material of the present embodiment, but the reference of the content is “100% by mass of the total friction material composition”.
  • this invention also provides the friction material formed by shape
  • the friction material formed by molding the friction material composition of the present embodiment includes, for example, a method of hot-pressing a preform formed by preforming the friction material composition of the present embodiment, and the friction material composition of the present embodiment. It can be produced by a method such as direct hot pressing, heat treatment as necessary, and thermosetting the binder.
  • the specific manufacturing method is as described in the manufacturing method of the friction material of the present embodiment and the examples described later.
  • the vehicle of this embodiment is a vehicle equipped with the friction member of this embodiment.
  • the vehicle according to the present embodiment include a vehicle in which the friction member according to the present embodiment is used for a disc brake pad, a brake lining, a clutch facing, an electromagnetic brake, a holding brake, and the like.
  • the vehicle include large vehicles, medium-sized vehicles, ordinary vehicles, large special vehicles, small special vehicles, large motorcycles, ordinary motorcycles, and the like.
  • passenger cars such as electric vehicles and hybrid vehicles equipped with a regenerative braking system are particularly suitable because they can exhibit excellent rust removing properties even in braking at low loads.
  • Examples 1 to 4 and Comparative Examples 1 and 2 [Production of disc brake pads]
  • the materials were blended according to the blending amounts (% by mass) shown in Table 1, and the friction material compositions of Examples 1 to 4 and Comparative Examples 1 to 2 were obtained.
  • the friction material composition is mixed with a Ladige (registered trademark) mixer (manufactured by Matsubo Co., Ltd., trade name: Ladige mixer M20), and the mixture is preformed with a molding press (manufactured by Oji Machinery Co., Ltd.). did.
  • Ladige registered trademark
  • the obtained preform is molded using a molding press (manufactured by Sanki Seiko Co., Ltd.) under the conditions of a molding temperature of 150 ° C., a molding pressure of 30 MPa, and a molding time of 5 minutes, and a backing metal (manufactured by Hitachi Automotive Systems). Together with heating and pressing. Subsequently, the obtained molded product was heat-treated at 200 ° C. for 4 hours, polished using a rotary polishing machine, subjected to scorch treatment at 500 ° C., and a disc brake pad (friction material thickness 9 mm, friction material projected area). 52 cm 2 ) was obtained.
  • a molding press manufactured by Sanki Seiko Co., Ltd.
  • shot content when simply described as “shot content”, it means the content (mass%) of shot (X2) in the total amount of inorganic fibers (X1) and shot (X2).
  • shot content in the friction material means the content (mass%) of the shot (X2) with respect to 100 mass% of the total friction material.
  • Resin A Silicone-modified phenolic resin (PR54529 manufactured by Sumitomo Bakelite Co., Ltd.)
  • Resin B Acrylic rubber modified phenolic resin (PR55291A manufactured by Sumitomo Bakelite Co., Ltd.)
  • Cashew dust A Black cashew dust, average particle size 150-500 ⁇ m
  • Cashew dust B Silicone rubber coated cashew dust, average particle size 150-500 ⁇ m ⁇ Rubber component (tire rubber powder): Powder TPA manufactured by Carquest Co., Ltd.
  • Examples 1 to 4 show the friction coefficient stability during low-speed and low-temperature braking at the same level as Comparative Example 1 containing copper, and the friction coefficient and rust removing property during normal braking are better than Comparative Example 1. .
  • Examples 1 to 4 have a friction coefficient variation rate during one braking, a friction coefficient in a normal braking region, and a comparative example 2 using a mineral fiber A having a shot content of less than 0.2% by mass. It is excellent in rust removal property, and it is understood that the stability of the excellent friction coefficient in the low-speed and low-temperature braking region and the excellent friction coefficient in the normal braking region are compatible, and the rust removal property is excellent.
  • the friction material, the friction material composition and the friction member of the present invention are excellent in rust removal performance without using copper having a high environmental load as compared with conventional products. It is suitable for a brake pad for a passenger car equipped with a control brake.

Abstract

The present invention relates to a friction material which is either copper-free or has a copper content of no more than 0.5 mass% in terms of the copper element. The friction material contains inorganic fibers (X1) and shot (X2) of the inorganic fibers (X1), and the shot (X2) content is at least 0.2 mass% of the total amount of inorganic fibers (X1) and shot (X2).

Description

摩擦材、摩擦材組成物、摩擦部材及び車両Friction material, friction material composition, friction member and vehicle
　本発明は、摩擦材、摩擦材組成物、摩擦部材及び車両に関する。 The present invention relates to a friction material, a friction material composition, a friction member, and a vehicle.
　自動車等には、制動のためにディスクブレーキパッド、ブレーキライニング等の摩擦材が使用されている。これらの摩擦材は、相手材となるディスクロータ、ブレーキドラム等と摩擦することによって制動の役割を果たす。そのため摩擦材には、使用条件に応じた適切な摩擦係数（効き特性）が求められるだけではなく、ブレーキ鳴きが発生しにくいこと（鳴き特性）、摩擦材の寿命が長いこと（耐摩耗性）等が要求される。 In automobiles, friction materials such as disc brake pads and brake linings are used for braking. These friction materials play a role of braking by friction with a disk rotor, a brake drum, or the like which is a counterpart material. For this reason, friction materials not only require an appropriate coefficient of friction (effectiveness characteristics) according to the conditions of use, but also make it difficult for brake noise to occur (squeal characteristics), and the friction material has a long life (wear resistance). Etc. are required.
　摩擦材は繊維基材としてスチール繊維を３０～６０質量％含有するセミメタリック材と、スチール繊維を３０質量％未満含有するロースチール材と、スチール繊維を含有しないＮＡО（Non-Asbestos Organic）材に大別される。ただし、スチール繊維を微量に含有する摩擦材もＮＡО材に分類されることがある。 Friction materials include semi-metallic materials containing 30 to 60% by mass of steel fibers as a fiber base material, raw steel materials containing less than 30% by mass of steel fibers, and NAO (Non-Asbestos Organic) materials that do not contain steel fibers. Broadly divided. However, friction materials containing a small amount of steel fibers may be classified as NAO materials.
　ＮＡО材はスチール繊維を含有しないため、セミメタリック材及びロースチール材と比較して、相手材であるディスクロータへの攻撃性が低いという特徴がある。このような利点から、現在、日本、米国等では効き、鳴き及び耐摩耗性のバランスに優れるＮＡО材が主流となっている。一方、欧州では高速制動時の摩擦係数保持の観点からロースチール材が用いられることが多かったが、近年は市場の高級志向化に応えるべく、タイヤのホイール汚れ及びブレーキ鳴きが発生しにくいＮＡО材が用いられることが増えてきている。 Since NAO material does not contain steel fibers, it has a feature that it is less aggressive to the disk rotor as the counterpart material than semi-metallic material and low steel material. Because of these advantages, NAO materials that are effective in Japan, the United States, etc., and have a good balance between squealing and wear resistance, are currently mainstream. On the other hand, in Europe, low steel materials were often used from the viewpoint of maintaining a friction coefficient during high-speed braking, but in recent years, NAO materials are less prone to tire wheel dirt and brake noise in order to respond to a higher-grade market. Are increasingly being used.
　ＮＡＯ材は、粉末又は繊維の状態の銅を含有するものが一般的である。しかし、銅、銅合金等を含有する摩擦材は、制動時に発生する摩耗粉中に銅を含むため、河川、湖等を汚染する可能性が示唆されている。そのため、米国のカリフォルニア州、ワシントン州等では２０２１年以降は銅を５質量％以上、２０２３年以降は銅を０．５質量％以上含有する摩擦材の販売及び新車への組み付けを禁止する法案が可決されており、これに対応するため銅を含有しない、又は銅の含有量が少ないＮＡＯ材の開発が急務となっている。 The NAO material generally contains copper in a powder or fiber state. However, friction materials containing copper, copper alloys, and the like contain copper in wear powder generated during braking, and thus have been suggested to possibly contaminate rivers, lakes, and the like. For this reason, in California, Washington, etc. in the United States, there is a bill that prohibits the sale of friction materials containing more than 5% by mass of copper after 2021, and the addition of 0.5% by mass of copper after 2023, and the assembly into new cars. In response to this, there is an urgent need to develop a NAO material that does not contain copper or has a low copper content.
　銅の代表的な機能の１つ目として、熱伝導率の付与が挙げられる。銅は熱伝導率が高いため、制動時に発生した熱を摩擦界面から拡散させることで、過度の温度上昇による摩耗を抑制する。
　銅の代表的な機能の２つ目として、高温制動時における摩擦界面の保護が挙げられる。
　銅は延性及び展性が高いため、制動によって摩擦材表面に延びて被膜を形成する。その結果、高速高温制動時に摩擦材の摩耗を低減すると共に、安定した摩擦係数の発現が可能となる。また、銅の延展膜が研削材を保持しやすくなるので、低速低温制動域においても良好な摩擦係数を発現可能となる。
　したがって、銅を含有しない、又は銅の含有量が少ないＮＡＯ材を開発するためには、上記のような熱伝導率の向上、界面保護及び研削材保持の観点から、銅代替技術が必要となる。 One of the typical functions of copper is to impart thermal conductivity. Since copper has high thermal conductivity, wear caused by excessive temperature rise is suppressed by diffusing heat generated during braking from the friction interface.
The second typical function of copper is protection of the friction interface during high-temperature braking.
Since copper has high ductility and malleability, it extends to the friction material surface by braking to form a coating. As a result, it is possible to reduce friction material wear during high-speed and high-temperature braking and to develop a stable friction coefficient. Further, since the copper spreading film can easily hold the abrasive, a good friction coefficient can be expressed even in the low-speed and low-temperature braking region.
Therefore, in order to develop a NAO material that does not contain copper or has a low copper content, a copper replacement technique is required from the viewpoints of improving the thermal conductivity, protecting the interface, and holding the abrasive. .
　このような動きの中、銅を含有しない、又は銅の含有量が少ない摩擦材について検討されている（例えば、特許文献１、２等）。 In such a movement, friction materials that do not contain copper or have a low copper content are being studied (for example, Patent Documents 1 and 2).
特開２０１５－２０５９５９号公報JP2015-205959A 特開２０１５－０５９１２５号公報Japanese Patent Laying-Open No. 2015-059125
　また、近年、上記の銅代替とは別の観点で重要な課題が発生している。それは、回生ブレーキに代表される制御ブレーキへの適合性である。従来の油圧ブレーキでは、ドライバーがブレーキペダルからの入力を微調整することで、車両の制動力を適時調整してきた。
　しかし、制御ブレーキでは、制動の一部をシステム側が担うため、摩擦材が発現する摩擦係数が極端に変動してしまうと、制御に不具合が生じてしまう。例えば、摩擦係数が極端に低下すると、制動距離が長くなり過ぎて最悪の場合事故の原因となり得る。したがって、制御ブレーキの精度を高めるためには、摩擦材が発現する摩擦係数がいかなるときも安定していることが極めて重要である。 In recent years, important issues have arisen from a viewpoint different from the above copper replacement. It is adaptability to a control brake represented by a regenerative brake. In conventional hydraulic brakes, the driver has adjusted the braking force of the vehicle in a timely manner by finely adjusting the input from the brake pedal.
However, in the control brake, since the system side takes part of the braking, if the friction coefficient expressed by the friction material fluctuates extremely, a problem occurs in the control. For example, if the friction coefficient is extremely reduced, the braking distance becomes too long, which may cause an accident in the worst case. Therefore, in order to increase the accuracy of the control brake, it is extremely important that the friction coefficient expressed by the friction material is stable at any time.
　摩擦係数が変動する代表例として、銅を含有しない摩擦材における低速低温制動域の摩擦係数低下が挙げられる。銅を含有しない摩擦材では、低速低温制動域においてディスクロータ表面に移着膜を形成し難く、研削材保持の効果を発現し難い。その結果、研削作用によるディスクロータへの攻撃性及びディスクロータ由来の鉄成分とディスクロータの間に生じるせん断抗力が低下するので、通常時に比べて摩擦係数が低下する傾向にある。その場合、上記のように、制動距離が長くなり、ブレーキ力が低下してしまうなどの不具合が生じ、ドライバーの快適性が損なわれてしまう。 A typical example of the friction coefficient variation is a decrease in the friction coefficient in a low-speed and low-temperature braking region in a friction material that does not contain copper. In the friction material not containing copper, it is difficult to form a transfer film on the surface of the disk rotor in the low-speed and low-temperature braking region, and it is difficult to exhibit the effect of holding the abrasive. As a result, the aggressiveness to the disk rotor due to the grinding action and the shear drag generated between the iron component derived from the disk rotor and the disk rotor are reduced, so that the friction coefficient tends to be lower than in the normal case. In this case, as described above, the braking distance becomes long and the braking force is reduced, so that the driver's comfort is impaired.
　また、低速低温制動における一制動中の摩擦係数変動率の増大も、摩擦係数が変動する代表例として挙げられる。銅を含有しない摩擦材では、制動時に発生した摩耗粉の排出性が低く、摩耗粉が摩擦材とディスクロータとの摩擦界面に堆積しやすい。その結果、摩擦界面での粉体抵抗が上がるため、摩擦係数の変動率が大きくなる。これにより、ブレーキをかけた停止際に鳴きが発生するなどの不具合が生じ、ドライバーの快適性が損なわれる。 In addition, an increase in the coefficient of friction variation during one braking in low-speed low-temperature braking is a typical example in which the coefficient of friction varies. The friction material containing no copper has a low ability to discharge wear powder generated during braking, and the wear powder tends to accumulate at the friction interface between the friction material and the disk rotor. As a result, the powder resistance at the friction interface is increased, and the coefficient of variation of the friction coefficient is increased. As a result, problems such as squealing occur when the brake is applied and the driver's comfort is impaired.
　回生ブレーキでは、従来の油圧ブレーキに比べて、摩擦で得られる制動力の比率が低下、すなわち制動負荷が低下する。そのため、ロータの表面に発錆した錆を除去することが困難となり、ロータとブレーキパッドとの間で錆による固着が発生し、発進時に摩擦材が■離する場合がある。したがって、回生ブレーキへの適合性を高めるためには、ロータ表面に発錆した錆を除去可能な性能をブレーキパッドに付与することが求められる。 In regenerative braking, the ratio of braking force obtained by friction is reduced, that is, the braking load is reduced, as compared with a conventional hydraulic brake. For this reason, it is difficult to remove the rust generated on the surface of the rotor, and adhesion due to rust occurs between the rotor and the brake pad, and the friction material may be separated at the start. Therefore, in order to improve the adaptability to the regenerative brake, it is required to provide the brake pad with a performance capable of removing rust generated on the rotor surface.
　このような観点から考えると、特許文献１及び２に開示されている技術は、銅の高い熱伝導率性及び高温潤滑性に着目した、高速高温制動時の摩擦特性の補完のみを課題とするものであり、低速低温制動域の摩擦係数の安定性、錆取り性、その他の摩擦特性については考慮されていない。 From this point of view, the techniques disclosed in Patent Documents 1 and 2 focus only on the high thermal conductivity and high-temperature lubricity of copper, and only complement the friction characteristics during high-speed and high-temperature braking. Therefore, the stability of the friction coefficient in the low-speed low-temperature braking region, the rust removal property, and other friction characteristics are not considered.
　そこで、本発明は、銅を含まない、又は含んでいてもその含有量が、銅元素として０．５質量％以下の環境有害性及び人体有害性が低い組成で、低速低温制動域における優れた摩擦係数の安定性と、通常制動域における優れた摩擦係数とを両立し、錆取り性に優れる摩擦材、摩擦材組成物、該摩擦材を用いた摩擦部材及び車両を提供することを目的とする。 Therefore, the present invention does not contain copper, or even if it contains copper, the content thereof is 0.5% by mass or less as a copper element, and the composition is low in environmental and human harm, and is excellent in a low-speed low-temperature braking region. An object of the present invention is to provide a friction material, a friction material composition, a friction member using the friction material, and a vehicle that have both the stability of the friction coefficient and the excellent friction coefficient in the normal braking range and are excellent in rust removal. .
　本発明者は、上記目的を達成するために鋭意研究を重ねた結果、特定量のショットを含む無機繊維を含有させた摩擦材が、低速低温制動域における優れた摩擦係数の安定性と、通常制動域における優れた摩擦係数とを両立し、錆取り性に優れるものとなることを見出した。すなわち、本発明は、下記［１］～［２０］に関する。
［１］銅を含まない、又は含んでいてもその含有量が、銅元素として０．５質量％以下の摩擦材であり、無機繊維（Ｘ１）と該無機繊維（Ｘ１）のショット（Ｘ２）とを含有し、前記ショット（Ｘ２）の含有量が、無機繊維（Ｘ１）及びショット（Ｘ２）の総量中、０．２質量％以上である、摩擦材。
［２］前記無機繊維（Ｘ１）の平均繊維長が、１００～８００μｍである、上記［１］に記載の摩擦材。
［３］前記無機繊維（Ｘ１）とショット（Ｘ２）の合計含有量が、摩擦材全量１００質量％に対して、１．０質量％以上１０．０質量％未満である、上記［１］又は［２］に記載の摩擦材。
［４］前記ショット（Ｘ２）の含有量が、無機繊維（Ｘ１）及びショット（Ｘ２）の総量中、０．２～１０質量％である、上記［１］～［３］のいずれかに記載の摩擦材。
［５］前記無機繊維（Ｘ１）及びショット（Ｘ２）中におけるＡｌ２Ｏ３の含有量が、１～３５質量％である、上記［１］～［４］のいずれかに記載の摩擦材。
［６］さらに、無機充填材として、平均粒子径が０．４～２μｍの珪酸ジルコニウムを、摩擦材全量１００質量％に対して、４～１０質量％含有する、上記［１］～［５］のいずれかに記載の摩擦材。
［７］さらに、無機充填材として、非針状であって平均粒子径が２～５０μｍのチタン酸塩を、摩擦材全量１００質量％に対して、１５～２５質量％含有する、上記［１］～［６］のいずれかに記載の摩擦材。
［８］さらに、無機充填材として、酸化ジルコニウムを、摩擦材全量１００質量％に対して、１０～２０質量％含有する、上記［１］～［７］のいずれかに記載の摩擦材。
［９］さらに、無機充填材として、ウォラストナイトを、摩擦材全量１００質量％に対して、２～１０質量％含有する、上記［１］～［８］のいずれかに記載の摩擦材。
［１０］上記［１］～［９］のいずれかに記載の摩擦材と裏金とを一体化してなる摩擦部材。
［１１］上記［１０］に記載の摩擦部材を搭載した車両。
［１２］銅を含まない、又は含んでいてもその含有量が、銅元素として０．５質量％以下の摩擦材組成物であり、無機繊維（Ｘ１）と該無機繊維（Ｘ１）のショット（Ｘ２）とを含有し、前記ショット（Ｘ２）の含有量が、無機繊維（Ｘ１）及びショット（Ｘ２）の総量中、０．２質量％以上である、摩擦材組成物。
［１３］前記無機繊維（Ｘ１）の平均繊維長が、１００～８００μｍである、上記［１２］に記載の摩擦材組成物。
［１４］前記無機繊維（Ｘ１）とショット（Ｘ２）の合計含有量が、摩擦材組成物全量１００質量％に対して、１．０質量％以上１０．０質量％未満である、上記［１２］又は［１３］に記載の摩擦材組成物。
［１５］前記ショット（Ｘ２）の含有量が、無機繊維（Ｘ１）及びショット（Ｘ２）の総量中、０．２～１０質量％である、上記［１２］～［１４］のいずれかに記載の摩擦材組成物。
［１６］前記無機繊維（Ｘ１）及びショット（Ｘ２）中におけるＡｌ２Ｏ３の含有量が、１～３５質量％である、上記［１２］～［１５］のいずれかに記載の摩擦材組成物。
［１７］さらに、無機充填材として、平均粒子径が０．４～２μｍの珪酸ジルコニウムを、摩擦材組成物全量１００質量％に対して、４～１０質量％含有する、上記［１２］～［１６］のいずれかに記載の摩擦材組成物。
［１８］さらに、無機充填材として、非針状であって平均粒子径が２～５０μｍのチタン酸塩を、摩擦材組成物全量１００質量％に対して、１５～２５質量％含有する、上記［１２］～［１７］のいずれかに記載の摩擦材組成物。
［１９］さらに、無機充填材として、酸化ジルコニウムを、摩擦材組成物全量１００質量％に対して、１０～２０質量％含有する、上記［１２］～［１８］のいずれかに記載の摩擦材組成物。
［２０］さらに、無機充填材として、ウォラストナイトを、摩擦材組成物全量１００質量％に対して、２～１０質量％含有する、上記［１２］～［１９］のいずれかに記載の摩擦材組成物。 As a result of intensive studies to achieve the above object, the present inventor has found that a friction material containing inorganic fibers containing a specific amount of shots has excellent friction coefficient stability in a low-speed low-temperature braking region, and usually The present inventors have found that the excellent friction coefficient in the braking region is compatible and the rust removing property is excellent. That is, the present invention relates to the following [1] to [20].
[1] Copper is not included, or even if it is included, the content thereof is a friction material of 0.5% by mass or less as a copper element, and the inorganic fiber (X1) and the shot (X2) of the inorganic fiber (X1) And the content of the shot (X2) is 0.2% by mass or more in the total amount of the inorganic fibers (X1) and the shot (X2).
[2] The friction material according to [1], wherein the inorganic fiber (X1) has an average fiber length of 100 to 800 μm.
[3] The above [1], wherein the total content of the inorganic fibers (X1) and the shot (X2) is 1.0% by mass or more and less than 10.0% by mass with respect to 100% by mass of the total amount of the friction material. The friction material according to [2].
[4] The content of the shot (X2) is 0.2 to 10% by mass in the total amount of the inorganic fibers (X1) and the shot (X2), according to any one of the above [1] to [3] Friction material.
[5] The friction material according to any one of [1] to [4], wherein the content of Al 2 O 3 in the inorganic fiber (X1) and the shot (X2) is 1 to 35% by mass.
[6] The above [1] to [5], further comprising 4 to 10% by mass of zirconium silicate having an average particle diameter of 0.4 to 2 μm as an inorganic filler with respect to 100% by mass of the total friction material. The friction material according to any one of the above.
[7] The above [1] further contains 15 to 25% by mass of a non-acicular titanate having an average particle diameter of 2 to 50 μm as an inorganic filler with respect to 100% by mass of the total friction material. ] To [6].
[8] The friction material according to any one of [1] to [7], further comprising 10 to 20% by mass of zirconium oxide as an inorganic filler with respect to 100% by mass of the total friction material.
[9] The friction material according to any one of [1] to [8], further comprising 2 to 10% by mass of wollastonite as an inorganic filler with respect to 100% by mass of the total friction material.
[10] A friction member obtained by integrating the friction material according to any one of [1] to [9] and a back metal.
[11] A vehicle equipped with the friction member according to [10].
[12] A friction material composition that does not contain copper or contains copper, and the content thereof is 0.5% by mass or less as a copper element, and shots of inorganic fibers (X1) and inorganic fibers (X1) ( X2), and the content of the shot (X2) is 0.2% by mass or more in the total amount of the inorganic fibers (X1) and the shot (X2).
[13] The friction material composition according to [12], wherein the inorganic fiber (X1) has an average fiber length of 100 to 800 μm.
[14] The above [12], wherein the total content of the inorganic fibers (X1) and the shots (X2) is 1.0% by mass or more and less than 10.0% by mass with respect to 100% by mass of the total friction material composition. ] Or the friction material composition according to [13].
[15] The content of the shot (X2) is 0.2 to 10% by mass in the total amount of the inorganic fibers (X1) and the shot (X2), according to any one of the above [12] to [14] The friction material composition.
[16] The friction material composition according to any one of [12] to [15], wherein the content of Al 2 O 3 in the inorganic fiber (X1) and the shot (X2) is 1 to 35% by mass. object.
[17] The above [12] to [12], further containing 4 to 10% by weight of zirconium silicate having an average particle size of 0.4 to 2 μm as an inorganic filler with respect to 100% by weight of the total amount of the friction material composition. 16]. The friction material composition according to any one of 16).
[18] Further, the inorganic filler contains non-acicular titanate having an average particle diameter of 2 to 50 μm in an amount of 15 to 25% by mass with respect to 100% by mass of the total amount of the friction material composition. [12] The friction material composition according to any one of [17].
[19] The friction material according to any one of [12] to [18], further comprising 10 to 20% by mass of zirconium oxide as an inorganic filler with respect to 100% by mass of the total amount of the friction material composition. Composition.
[20] The friction according to any one of [12] to [19], further comprising wollastonite as an inorganic filler in an amount of 2 to 10% by mass with respect to 100% by mass of the total amount of the friction material composition. Material composition.
　本発明によれば、銅を含まない、又は含んでいてもその含有量が、銅元素として０．５質量％以下の環境有害性及び人体有害性が低い組成で、低速低温制動域における優れた摩擦係数の安定性と、通常制動域における優れた摩擦係数とを両立し、錆取り性に優れる摩擦材、摩擦材組成物、該摩擦材を用いた摩擦部材及び車両を提供することができる。 According to the present invention, copper does not contain, or even if contained, the content is 0.5% by mass or less as a copper element, and the composition is low in environmental and human harm, and is excellent in a low-speed low-temperature braking region. It is possible to provide a friction material, a friction material composition, a friction member using the friction material, and a vehicle that have both the stability of the friction coefficient and the excellent friction coefficient in the normal braking range and are excellent in rust removal.
　以下、本実施形態の摩擦材、摩擦材組成物及び摩擦部材について詳述するが、本発明は以下の実施形態に限定されるものではない。
　なお、本実施形態の摩擦材及び摩擦材組成物は、アスベストを含有しないものであり、いわゆるノンアスベスト摩擦材及びノンアスベスト摩擦材組成物である。 Hereinafter, although the friction material, friction material composition, and friction member of this embodiment are explained in full detail, this invention is not limited to the following embodiment.
In addition, the friction material and friction material composition of this embodiment do not contain asbestos, and are a so-called non-asbestos friction material and non-asbestos friction material composition.
［摩擦材及び摩擦部材］
　本実施形態に係る摩擦材は、銅を含まない、又は含んでいてもその含有量が、銅元素として０．５質量％以下の摩擦材であり、無機繊維（Ｘ１）と該無機繊維（Ｘ１）のショット（Ｘ２）とを含有し、前記ショット（Ｘ２）の含有量が、無機繊維（Ｘ１）及びショット（Ｘ２）の総量中、０．２質量％以上である、摩擦材である。 [Friction material and friction member]
The friction material which concerns on this embodiment is a friction material which is 0.5 mass% or less as a copper element even if it does not contain copper or contains copper, and inorganic fiber (X1) and this inorganic fiber (X1) ) Shot (X2), and the content of the shot (X2) is 0.2% by mass or more in the total amount of the inorganic fibers (X1) and the shot (X2).
　本実施形態の摩擦材は、銅を含まない、又は含んでいてもその含有量が、銅元素として０．５質量％以下と極微量である。このため、本実施形態の摩擦材は、環境有害性及び人体有害性が低いものとなる。
　なお、上記の「銅」とは、繊維状、粉末状等の銅；銅合金、銅化合物などに含まれる銅元素であり、「銅の含有量」は摩擦材全量１００質量％に対する含有量を示す。
　銅の含有量は、環境有害性及び人体有害性の観点から、摩擦材全量１００質量％に対して、０．５質量％未満が好ましく、０．３質量％以下がより好ましく、０．１質量％以下がさらに好ましく、銅を含有しないことが特に好ましい。 Even if the friction material of this embodiment does not contain copper, the content is 0.5 mass% or less as a copper element, and is very trace amount. For this reason, the friction material of this embodiment becomes a thing with a low environmental hazard and a human body hazard.
In addition, said "copper" is copper element contained in copper, such as a fiber form and a powder form; copper alloy, a copper compound, etc., "copper content" is content with respect to 100 mass% of friction material whole quantity. Show.
The copper content is preferably less than 0.5% by mass, more preferably 0.3% by mass or less, and more preferably 0.1% by mass with respect to 100% by mass of the total amount of the friction material, from the viewpoints of environmental hazards and human injury. % Or less is more preferable, and it is particularly preferable not to contain copper.
＜摩擦材の構成成分＞
　本実施形態の摩擦材は、繊維基材、無機充填材、有機充填材及び結合材からなる群から選択される１種以上を含有することが好ましい。
　以下、本実施形態の摩擦材が含有する各成分について説明する。 <Constituent components of friction material>
It is preferable that the friction material of this embodiment contains 1 or more types selected from the group which consists of a fiber base material, an inorganic filler, an organic filler, and a binder.
Hereinafter, each component which the friction material of this embodiment contains is demonstrated.
＜繊維基材＞
　本実施形態に係る摩擦材は、繊維基材として、無機繊維を含有するものである。
　無機繊維は、繊維状により摩擦材を補強するだけでなく、組成、繊維長、靭性等の様々な素材特性を選定することで、摩擦係数、ロータ攻撃性等の摩擦特性を調整可能な成分である。 <Fiber base>
The friction material which concerns on this embodiment contains an inorganic fiber as a fiber base material.
Inorganic fiber is a component that not only reinforces the friction material in the form of fibers, but also allows adjustment of friction characteristics such as friction coefficient and rotor aggression by selecting various material characteristics such as composition, fiber length, and toughness. is there.
（無機繊維（Ｘ１）及びショット（Ｘ２））
　本実施形態に係る摩擦材は、無機繊維（Ｘ１）と該無機繊維（Ｘ１）のショット（Ｘ２）とを含有し、前記ショット（Ｘ２）の含有量が、無機繊維（Ｘ１）及びショット（Ｘ２）の総量中、０．２質量％以上である。
　本実施形態の摩擦材は、ショット（Ｘ２）の含有量が、無機繊維（Ｘ１）及びショット（Ｘ２）の総量中、０．２質量％以上であることにより、錆取り性に優れたものとなる。
　なお、本明細書における「ショット」とは、無機繊維の製造過程において、繊維になりきれないで粒のまま残る非繊維状粒子のことであり、粒子径は１２５μｍ以上である。ここで、「ショットの粒子径」とは、粒子投影像における粒子の長径を意味し、例えば、走査型電子顕微鏡（ＳＥＭ）を用いて測定することができる。 (Inorganic fiber (X1) and shot (X2))
The friction material according to the present embodiment includes the inorganic fiber (X1) and the shot (X2) of the inorganic fiber (X1), and the content of the shot (X2) is the inorganic fiber (X1) and the shot (X2). ) In the total amount of 0.2).
The friction material of the present embodiment is excellent in rust removing properties when the content of the shot (X2) is 0.2% by mass or more in the total amount of the inorganic fibers (X1) and the shot (X2). .
In the present specification, “shot” refers to non-fibrous particles that cannot remain as fibers and remain in the form of particles in the production process of inorganic fibers, and have a particle diameter of 125 μm or more. Here, the “shot particle diameter” means the long diameter of the particle in the particle projection image, and can be measured using, for example, a scanning electron microscope (SEM).
　無機繊維（Ｘ１）は、特に限定されないが、鉱物繊維であることが好ましい。
　なお、ここでいう鉱物繊維とは、スラグウール等の高炉スラグ、バサルトファイバー等の玄武岩；その他の天然岩石などを主成分として溶融紡糸した人造無機繊維であり、Ａｌ元素を含む天然鉱物であることがより好ましい。具体的には、ＳｉＯ２、Ａｌ２Ｏ３、ＣａＯ、ＭｇＯ、Ｆｅ２Ｏ３、Ｎａ２Ｏ等が含まれるものを鉱物繊維として用いることができる。 The inorganic fiber (X1) is not particularly limited, but is preferably a mineral fiber.
The mineral fiber referred to here is a man-made inorganic fiber that is melt-spun mainly composed of blast furnace slag such as slag wool, basalt such as basalt fiber; and other natural rocks, and is a natural mineral containing Al element. Is more preferable. Specifically, a material containing SiO 2 , Al 2 O 3 , CaO, MgO, Fe 2 O 3 , Na 2 O, or the like can be used as the mineral fiber.
　無機繊維（Ｘ１）は生体溶解性を有する無機繊維であることが好ましい。
　ここでいう生体溶解性を有する無機繊維とは、人体内に取り込まれた場合でも短時間で一部分解され体外に排出される特徴を有するものであり、例えば、生体溶解性の鉱物繊維が挙げられる。具体的には、化学組成がアルカリ酸化物、アルカリ土類酸化物総量（ナトリウム、カリウム、カルシウム、マグネシウム、バリウムの酸化物の総量）が１８質量％以上で、かつ呼吸による短期バイオ永続試験で、２０μｍ以上の繊維の質量半減期が４０日以内、又は腹膜内試験で過度の発癌性の証拠がない、又は長期呼吸試験で関連の病原性及び腫瘍発生がないことを満たす無機繊維を示す（ＥＵ指令９７／６９／ＥＣのＮｏｔａＱ（発癌性適用除外））。
　このような無機繊維（Ｘ１）としては、ＳｉＯ２－Ａｌ２Ｏ３－ＣａＯ－ＭｇＯ－Ｆｅ２Ｏ３－Ｎａ２Ｏ系繊維等が挙げられ、ＳｉＯ２、Ａｌ２Ｏ３、ＣａＯ、ＭｇＯ、Ｆｅ２Ｏ３、Ｎａ２Ｏ等を任意の組み合わせで含有する繊維が挙げられる。 The inorganic fiber (X1) is preferably an inorganic fiber having biosolubility.
The term “inorganic fiber having biosolubility” as used herein means that it is characterized in that even when it is taken into the human body, it is partially decomposed in a short time and discharged outside the body, and examples thereof include biosoluble mineral fibers. . Specifically, the chemical composition is alkali oxide, alkaline earth oxide total amount (total amount of oxides of sodium, potassium, calcium, magnesium, barium) is 18% by mass or more, and in a short-term biopermanent test by respiration, Inorganic fibers satisfying a mass half-life of fibers of 20 μm or more within 40 days, or no evidence of excessive carcinogenicity in intraperitoneal tests, or related pathogenicity and tumor development in long-term respiratory tests (EU Directive 97/69 / EC NotaQ (exclusion of carcinogenicity)).
Examples of such inorganic fibers (X1), SiO 2 -Al 2 O 3 -CaO-MgO-Fe 2 O 3 -Na 2 O -based fibers and the like, SiO 2, Al 2 O 3 , CaO, MgO, Examples thereof include fibers containing Fe 2 O 3 , Na 2 O and the like in any combination.
　無機繊維（Ｘ１）は、酸化カルシウム（以下、「ＣａＯ」ともいう）及び酸化マグネシウム（以下、「ＭｇＯ」ともいう）を含有する無機繊維であることが好ましい。
　なお、上記「ＣａＯ及びＭｇＯを含有する無機繊維」とは、ＣａＯ及びＭｇＯを、１本の繊維を構成する成分として含有する無機繊維を意味し、後述するＣａＯ及びＭｇＯ以外の各成分についても同様である。また、以下の無機繊維（Ｘ１）中における各成分の含有量とは、無機繊維（Ｘ１）全量１００質量％を基準とする含有量である。
　無機繊維（Ｘ１）中における、ＣａＯの含有量は、１５～３０質量％が好ましく、１７～２５質量％がより好ましく、１８～２２質量％がさらに好ましい。
　無機繊維（Ｘ１）中における、ＭｇＯの含有量は、３～２０質量％が好ましく、４～１５質量％がより好ましく、５～８質量％がさらに好ましい。
　無機繊維（Ｘ１）中における、ＣａＯ及びＭｇＯの総含有量は、１８～４０質量％が好ましく、２２～３５質量％がより好ましく、２５～３０質量％がさらに好ましい。 The inorganic fiber (X1) is preferably an inorganic fiber containing calcium oxide (hereinafter also referred to as “CaO”) and magnesium oxide (hereinafter also referred to as “MgO”).
The “inorganic fiber containing CaO and MgO” means an inorganic fiber containing CaO and MgO as components constituting one fiber, and the same applies to each component other than CaO and MgO described later. It is. Moreover, content of each component in the following inorganic fiber (X1) is content based on 100 mass% of inorganic fiber (X1) whole quantity.
The CaO content in the inorganic fibers (X1) is preferably 15 to 30% by mass, more preferably 17 to 25% by mass, and further preferably 18 to 22% by mass.
The content of MgO in the inorganic fiber (X1) is preferably 3 to 20% by mass, more preferably 4 to 15% by mass, and further preferably 5 to 8% by mass.
The total content of CaO and MgO in the inorganic fiber (X1) is preferably 18 to 40% by mass, more preferably 22 to 35% by mass, and further preferably 25 to 30% by mass.
　無機繊維（Ｘ１）は、ＣａＯ及びＭｇＯ以外のその他の酸化物を含有していてもよい。その他の酸化物としては、ＳｉＯ２、Ａｌ２Ｏ３、Ｎａ２Ｏ、Ｋ２Ｏ、ＴｉＯ２、Ｐ２Ｏ５、ＭｎＯ、Ｆｅ２Ｏ３、ＳｒＯ、ＺｒＯ２等が挙げられる。これらの中でも、ＳｉＯ２、Ａｌ２Ｏ３、Ｆｅ２Ｏ３を含有することが好ましい。
　無機繊維（Ｘ１）が、ＳｉＯ２、Ａｌ２Ｏ３及びＦｅ２Ｏ３からなる群から選択される１種以上を含有する場合、無機繊維（Ｘ１）中におけるその含有量は以下の通りである。
　ＳｉＯ２の含有量は、１０～６０質量％が好ましく、３０～５０質量％がより好ましく、３５～４７質量％がさらに好ましく、４０～４５質量％が特に好ましい。
　Ａｌ２Ｏ３の含有量は、１～３５質量％が好ましく、５～３２質量％がより好ましく、１０～３０質量％がさらに好ましく、１３～２５質量％がよりさらに好ましく、１５～２０質量％が特に好ましい。
　Ｆｅ２Ｏ３の含有量は、１～１０質量％が好ましく、２～９質量％がより好ましく、４～８質量％がさらに好ましい。
　無機繊維（Ｘ１）中におけるＣａＯ、ＭｇＯ、ＳｉＯ２、Ａｌ２Ｏ３及びＦｅ２Ｏ３の総含有量は、９０質量％以上が好ましく、９３質量％以上がより好ましく、９５質量％以上がさらに好ましい。また、該総含有量は、１００質量％以下であってもよく、９８質量％以下であってもよく、９７質量％以下であってもよい。 The inorganic fiber (X1) may contain other oxides other than CaO and MgO. Other oxides, SiO 2, Al 2 O 3 , Na 2 O, K 2 O, TiO 2, P 2 O 5, MnO, Fe 2 O 3, SrO, ZrO 2 and the like. Among these, it preferably contains SiO 2, Al 2 O 3, Fe 2 O 3.
Inorganic fibers (X1) is, when it contains one or more selected from the group consisting of SiO 2, Al 2 O 3 and Fe 2 O 3, the content in the inorganic fibers (X1) in are as follows .
The content of SiO 2 is preferably 10 to 60% by mass, more preferably 30 to 50% by mass, further preferably 35 to 47% by mass, and particularly preferably 40 to 45% by mass.
The content of Al 2 O 3 is preferably 1 to 35% by mass, more preferably 5 to 32% by mass, further preferably 10 to 30% by mass, still more preferably 13 to 25% by mass, and 15 to 20% by mass. Is particularly preferred.
The content of Fe 2 O 3 is preferably 1 to 10% by mass, more preferably 2 to 9% by mass, and further preferably 4 to 8% by mass.
The total content of CaO, MgO, SiO 2 , Al 2 O 3 and Fe 2 O 3 in the inorganic fiber (X1) is preferably 90% by mass or more, more preferably 93% by mass or more, and further more preferably 95% by mass or more. preferable. Further, the total content may be 100% by mass or less, 98% by mass or less, or 97% by mass or less.
　無機繊維（Ｘ１）が、さらに、Ｎａ２Ｏ、Ｋ２Ｏ、ＴｉＯ２、Ｐ２Ｏ５及びＭｎＯからなる群から選択される１種以上を含有する場合、無機繊維（Ｘ１）中におけるその含有量は以下の通りである。
　Ｎａ２Ｏの含有量は、１～５質量％が好ましく、１．５～４質量％がより好ましく、２～３質量％がさらに好ましい。
　Ｋ２Ｏの含有量は、０．１～１．５質量％が好ましく、０．２～１．２質量％がより好ましく、０．４～０．８質量％がさらに好ましい。
　ＴｉＯ２の含有量は、０．２～３質量％が好ましく、０．７～２質量％がより好ましく、１～１．５質量％がさらに好ましい。
　Ｐ２Ｏ５の含有量は、０．０１～１質量％が好ましく、０．１～０．５質量％がより好ましく、０．１５～０．３質量％がさらに好ましい。
　ＭｎＯの含有量は、０．０１～１質量％が好ましく、０．０５～０．５質量％がより好ましく、０．０７～０．２質量％がさらに好ましい。
　無機繊維（Ｘ１）中におけるＮａ２Ｏ、Ｋ２Ｏ、ＴｉＯ２、Ｐ２Ｏ５及びＭｎＯからなる群から選択される１種以上の総含有量は、０．５～１０質量％が好ましく、２～７質量％がより好ましく、３～５質量％がさらに好ましい。
　無機繊維（Ｘ１）中におけるＳｒＯの含有量は、錆び取り性、及び低速低温制動域の摩擦係数の安定性の観点から、０．１質量％未満が好ましく、０．０１質量％未満がより好ましい。また、無機繊維（Ｘ１）は、同様の観点から、ＳｒＯを含有しないことがさらに好ましい。
　無機繊維（Ｘ１）中におけるＺｒＯ２の含有量は、錆び取り性、及び低速低温制動域の摩擦係数の安定性の観点から、０．１質量％未満が好ましく、０．０１質量％未満がより好ましい。また、無機繊維（Ｘ１）は、同様の観点から、ＺｒＯ２を含有しないことがさらに好ましい。 In the case where the inorganic fiber (X1) further contains one or more selected from the group consisting of Na 2 O, K 2 O, TiO 2 , P 2 O 5 and MnO, its inclusion in the inorganic fiber (X1) The amounts are as follows.
The content of Na 2 O is preferably 1 to 5% by mass, more preferably 1.5 to 4% by mass, and still more preferably 2 to 3% by mass.
The content of K 2 O is preferably 0.1 to 1.5% by mass, more preferably 0.2 to 1.2% by mass, and further preferably 0.4 to 0.8% by mass.
The content of TiO 2 is preferably 0.2 to 3% by mass, more preferably 0.7 to 2% by mass, and further preferably 1 to 1.5% by mass.
The content of P 2 O 5 is preferably 0.01 to 1% by mass, more preferably 0.1 to 0.5% by mass, and further preferably 0.15 to 0.3% by mass.
The content of MnO is preferably 0.01 to 1% by mass, more preferably 0.05 to 0.5% by mass, and further preferably 0.07 to 0.2% by mass.
The total content of one or more selected from the group consisting of Na 2 O, K 2 O, TiO 2 , P 2 O 5 and MnO in the inorganic fiber (X1) is preferably 0.5 to 10% by mass, It is more preferably 2 to 7% by mass, and further preferably 3 to 5% by mass.
The content of SrO in the inorganic fiber (X1) is preferably less than 0.1% by mass, more preferably less than 0.01% by mass, from the viewpoint of rust removal and stability of the coefficient of friction in the low-speed and low-temperature braking region. . Moreover, it is more preferable that inorganic fiber (X1) does not contain SrO from the same viewpoint.
The content of ZrO 2 in the inorganic fiber (X1) is preferably less than 0.1% by mass and more preferably less than 0.01% by mass from the viewpoint of rust removal and stability of the coefficient of friction in the low-speed low-temperature braking region. preferable. Moreover, it is more preferable that inorganic fiber (X1) does not contain ZrO 2 from the same viewpoint.
　なお、無機繊維（Ｘ１）中におけるＣａＯ、ＭｇＯ及びその他の酸化物の含有量は、蛍光Ｘ線分析によって測定することができる。また、上記酸化物の含有量は、酸化物を形成する酸素以外の原子の含有量から換算される各酸化物の含有量とすることができる。 The contents of CaO, MgO and other oxides in the inorganic fiber (X1) can be measured by fluorescent X-ray analysis. Moreover, content of the said oxide can be made into content of each oxide converted from content of atoms other than oxygen which forms an oxide.
　無機繊維（Ｘ１）の平均繊維長は、１００～８００μｍが好ましく、１４０～５００μｍがより好ましく、１７０～３００μｍがさらに好ましい。平均繊維長が上記範囲であると、ロータ攻撃性の著しい増大等の弊害を与えることなく、摩擦係数の安定性を高めることができる。
　無機繊維（Ｘ１）の平均繊維径は、１～１０μｍが好ましく、２～８μｍがより好ましく、３～６μｍがさらに好ましい。平均繊維径が上記範囲であると、ロータ攻撃性の著しい増大等の弊害を与えることなく、摩擦係数の安定性を高めることができる。
　ここで、平均繊維長及び平均繊維径とは、該当する繊維の長さ又は直径の平均値を示した数平均繊維長又は数平均繊維径のことをいう。例えば２００μｍの平均繊維長とは、摩擦材組成物の原料として用いる繊維を無作為に５０個選択し、光学顕微鏡で繊維長を測定し、その平均値が２００μｍであることを示す。 The average fiber length of the inorganic fibers (X1) is preferably 100 to 800 μm, more preferably 140 to 500 μm, and further preferably 170 to 300 μm. When the average fiber length is in the above range, the stability of the friction coefficient can be enhanced without causing adverse effects such as a significant increase in rotor attack.
The average fiber diameter of the inorganic fibers (X1) is preferably 1 to 10 μm, more preferably 2 to 8 μm, and even more preferably 3 to 6 μm. When the average fiber diameter is in the above range, the stability of the friction coefficient can be improved without causing adverse effects such as a significant increase in rotor attack.
Here, the average fiber length and the average fiber diameter mean a number average fiber length or a number average fiber diameter indicating an average value of the length or diameter of the corresponding fiber. For example, the average fiber length of 200 μm indicates that 50 fibers 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.
　上記の通り、本実施形態の摩擦材は、無機繊維（Ｘ１）と該無機繊維（Ｘ１）の製造過程において発生するショット（Ｘ２）を含有するものである。
　したがって、ショット（Ｘ２）は、無機繊維（Ｘ１）と同じ材質を有する。
　なお、ショット（Ｘ２）は、一般的には、原料として使用する無機繊維（Ｘ１）中に混在しているため、通常、摩擦材の製造過程においては、無機繊維（Ｘ１）とショット（Ｘ２）とは同時に配合されるが、無機繊維（Ｘ１）から単離したショット（Ｘ２）を、無機繊維（Ｘ１）と別に配合してもよい。 As described above, the friction material of the present embodiment contains the inorganic fiber (X1) and the shot (X2) generated in the manufacturing process of the inorganic fiber (X1).
Therefore, the shot (X2) has the same material as the inorganic fiber (X1).
In general, the shot (X2) is mixed in the inorganic fiber (X1) used as a raw material. Therefore, in the process of manufacturing the friction material, the inorganic fiber (X1) and the shot (X2) are usually used. The shot (X2) isolated from the inorganic fiber (X1) may be blended separately from the inorganic fiber (X1).
　ショット（Ｘ２）の平均粒子径は、錆取り性の観点から、１２５～３００μｍが好ましく、１２５～２００μｍがより好ましく、１２５～１５０μｍがさらに好ましい。
　ショット（Ｘ２）の平均粒子径は、例えば、走査型電子顕微鏡（ＳＥＭ）を用いて、任意の５０個のショットの粒子径を測定し、その平均値として求めることができる。なお、ここでの「ショット」及び「ショットの粒子径」の定義は上記の通りである。 The average particle size of the shot (X2) is preferably 125 to 300 μm, more preferably 125 to 200 μm, and further preferably 125 to 150 μm from the viewpoint of rust removal.
The average particle diameter of the shot (X2) can be obtained as an average value by measuring the particle diameter of any 50 shots using, for example, a scanning electron microscope (SEM). The definitions of “shot” and “shot particle size” are as described above.
　ショット（Ｘ２）の含有量は、錆取り性の観点から、無機繊維（Ｘ１）及びショット（Ｘ２）の総量中、０．２質量％以上であり、０．２～２０質量％が好ましく、０．２～１５質量％がより好ましく、０．２～１２質量％がさらに好ましく、０．２～１０質量％がよりさらに好ましく、０．２～８質量％がよりさらに好ましく、０．２～６質量％が特に好ましく、０．２～５質量％が最も好ましい。 The content of the shot (X2) is 0.2% by mass or more, preferably 0.2 to 20% by mass in the total amount of the inorganic fibers (X1) and the shot (X2) from the viewpoint of rust removing property, and is preferably 0.2 to 20% by mass. 2 to 15% by mass is more preferable, 0.2 to 12% by mass is further preferable, 0.2 to 10% by mass is further more preferable, 0.2 to 8% by mass is further more preferable, and 0.2 to 6% by mass. % Is particularly preferable, and 0.2 to 5% by mass is most preferable.
　本実施形態の摩擦材中におけるショット（Ｘ２）の含有量は、摩擦材全量１００質量％に対して、０．００１～２質量％が好ましく、０．００２～１質量％がより好ましく、０．００３～０．７５質量％がさらに好ましく、０．００５～０．５質量％よりさらに好ましく、０．００７～０．３質量％が特に好ましく、０．０１～０．２５質量％が最も好ましい。 The content of the shot (X2) in the friction material of this embodiment is preferably 0.001 to 2% by mass, more preferably 0.002 to 1% by mass with respect to 100% by mass of the total amount of the friction material. 003 to 0.75% by mass is more preferable, 0.005 to 0.5% by mass is more preferable, 0.007 to 0.3% by mass is particularly preferable, and 0.01 to 0.25% by mass is most preferable.
　本実施形態の摩擦材中における無機繊維（Ｘ１）とショット（Ｘ２）の合計含有量は、摩擦材全量１００質量％に対して、１．０質量％以上１０．０質量％未満であることが好ましい。上記合計含有量が上記範囲であると、低速低温制動域において高い摩擦係数の安定性が得られ、一制動中の摩擦係数変動率も小さくなると共に、通常制動域において優れた摩擦係数が得られる。特に、無機繊維（Ｘ）の含有量が１．０質量％以上であると、低速低温制動域の摩擦係数安定性が担保されつつ、一制動中の摩擦係数変動率を小さくすることができる。また、無機繊維（Ｘ）の含有量が１０．０質量％未満であると、一制動中の摩擦係数変動率が低い状態で担保されつつ、低速低温制動域の摩擦係数安定性が良好となる。
　同様の観点から、本実施形態の摩擦材中における無機繊維（Ｘ１）とショット（Ｘ２）の合計含有量は、摩擦材全量１００質量％に対して、２．０～９．９質量％がより好ましく、４．０～８質量％がさらに好ましく、５．０～７質量％がよりさらに好ましい。 The total content of inorganic fibers (X1) and shots (X2) in the friction material of the present embodiment is 1.0% by mass or more and less than 10.0% by mass with respect to 100% by mass of the total friction material. preferable. When the total content is within the above range, high friction coefficient stability is obtained in the low-speed and low-temperature braking range, the coefficient of friction variation during one braking is reduced, and an excellent friction coefficient is obtained in the normal braking range. . In particular, when the content of the inorganic fiber (X) is 1.0% by mass or more, the coefficient of friction variation during one braking can be reduced while ensuring the coefficient of friction stability in the low-speed and low-temperature braking region. Further, when the content of the inorganic fiber (X) is less than 10.0% by mass, the friction coefficient stability in the low-speed and low-temperature braking region is improved while the friction coefficient variation rate during one braking is secured. .
From the same viewpoint, the total content of inorganic fibers (X1) and shots (X2) in the friction material of the present embodiment is more preferably 2.0 to 9.9% by mass with respect to 100% by mass of the total friction material. It is preferably 4.0 to 8% by mass, more preferably 5.0 to 7% by mass.
　本実施形態の摩擦材は、無機繊維（Ｘ１）の他にも、有機繊維、その他の無機繊維及び金属繊維からなる群から選択される１種以上を含有することが好ましい。これらの繊維基材は、摩擦材において補強作用を示すものである。なお、有機繊維、その他の無機繊維及び金属繊維は、各々について、１種を単独で用いてもよく、２種以上を併用してもよい。
　なお、本実施形態の摩擦材は、相手材であるディスクロータへの攻撃性を過度に高めない観点から、金属繊維を含まない、又は含んでいてもその含有量が、摩擦材全量１００質量％に対して、０．５質量％以下であることが好ましい。 It is preferable that the friction material of this embodiment contains 1 or more types selected from the group which consists of organic fiber, another inorganic fiber, and metal fiber besides inorganic fiber (X1). These fiber base materials exhibit a reinforcing action in the friction material. In addition, organic fiber, other inorganic fiber, and metal fiber may be used individually by 1 type, respectively, and may use 2 or more types together.
In addition, the friction material of this embodiment does not contain the metal fiber from the viewpoint of not excessively increasing the aggressiveness to the disk rotor which is the counterpart material, or the content thereof is 100% by mass of the total friction material. The content is preferably 0.5% by mass or less.
（有機繊維）
　有機繊維としては、アラミド繊維、アクリル繊維、セルロース繊維等が挙げられる。これらの中でも、耐熱性、補強効果及び適度な空隙付与の観点から、アラミド繊維が好ましい。アラミド繊維は、摩擦材に使用されている公知のものを使用することができる。有機繊維の平均繊維長は、例えば、６５０～１５００μｍであり、１０００～１３００μｍが好ましい。平均繊維長の測定方法は上記と同様である。
　本実施形態の摩擦材が有機繊維を含有する場合、その合計含有量は、摩擦材全量１００質量％に対して、０．５～１０質量％が好ましく、１～５質量％がより好ましく、２～４質量％がさらに好ましい。 (Organic fiber)
Examples of organic fibers include aramid fibers, acrylic fibers, and cellulose fibers. Among these, an aramid fiber is preferable from the viewpoints of heat resistance, a reinforcing effect, and appropriate provision of voids. The aramid fiber can use the well-known thing currently used for the friction material. The average fiber length of the organic fibers is, for example, 650 to 1500 μm, and preferably 1000 to 1300 μm. The method for measuring the average fiber length is the same as described above.
When the friction material of the present embodiment contains organic fibers, the total content is preferably 0.5 to 10% by mass, more preferably 1 to 5% by mass with respect to 100% by mass of the total friction material. More preferably, it is 4% by mass.
（その他の無機繊維）
　その他の無機繊維としては、セラミック繊維、生分解性セラミック繊維、鉱物繊維、炭素繊維、ガラス繊維、チタン酸カリウム繊維等が挙げられる。なお、人体への有害性の観点からは、チタン酸カリウム繊維等を含有しないことが好ましい。また、靭性が高い無機繊維の添加量を過度に多くすると、ロータ攻撃性が顕著に悪化してしまうため、無機繊維の靭性の観点から、セラミック繊維及び炭素繊維を含有しないことが好ましい。
　また、本実施形態の摩擦材は、所望する性能に応じて、その他の無機繊維を含有しないものであってもよい。
　なお、本明細書中、金属繊維は、無機繊維の定義に含まれないものとする。 (Other inorganic fibers)
Examples of other inorganic fibers include ceramic fibers, biodegradable ceramic fibers, mineral fibers, carbon fibers, glass fibers, and potassium titanate fibers. In addition, it is preferable not to contain potassium titanate fiber etc. from a viewpoint of the harmfulness to a human body. Moreover, since rotor attack property will deteriorate notably when the addition amount of the inorganic fiber with high toughness is increased excessively, it is preferable not to contain ceramic fiber and carbon fiber from the viewpoint of toughness of the inorganic fiber.
Moreover, the friction material of this embodiment may not contain other inorganic fibers according to the desired performance.
In the present specification, metal fiber is not included in the definition of inorganic fiber.
　本実施形態の摩擦材中における繊維基材の合計含有量は、摩擦材全量１００質量％に対して、６～２０質量％が好ましく、７～１７質量％がより好ましく、８～１５質量％がさらに好ましい。繊維基材の合計含有量が上記範囲であると、低速低温制動域及び通常制動域において、より高い摩擦係数の安定性が得られる。 The total content of the fiber base material in the friction material of the present embodiment is preferably 6 to 20% by mass, more preferably 7 to 17% by mass, and 8 to 15% by mass with respect to 100% by mass of the total friction material. Further preferred. When the total content of the fiber base is within the above range, higher friction coefficient stability is obtained in the low-speed and low-temperature braking region and the normal braking region.
＜無機充填材＞
　本実施形態の摩擦材は無機充填材を含有することが好ましい。
　無機充填材としては、チタン酸塩、ウォラストナイト、金属粉、黒鉛、研削材として使用される各種酸化物、その他の無機充填材等が挙げられる。
　無機充填材は、１種を単独で用いてもよく、２種以上を併用してもよい。
　金属粉としては、鉄粉、錫粉、亜鉛粉、アルミニウム粉、それらの合金粉等が挙げられる。
　ただし、本実施形態の摩擦材は、相手材であるディスクロータへの攻撃性を過度に高めない観点から、金属粉を含まない、又は含んでいてもその含有量が、摩擦材全量１００質量％に対して、０．５質量％未満であることが好ましく、０．１質量％未満であることがより好ましく、０．０１質量％未満であることがさらに好ましい。 <Inorganic filler>
The friction material of the present embodiment preferably contains an inorganic filler.
Examples of the inorganic filler include titanate, wollastonite, metal powder, graphite, various oxides used as an abrasive, and other inorganic fillers.
An inorganic filler may be used individually by 1 type, and may use 2 or more types together.
Examples of the metal powder include iron powder, tin powder, zinc powder, aluminum powder, and alloy powder thereof.
However, the friction material of the present embodiment does not contain metal powder from the viewpoint of not excessively increasing the aggressiveness to the disk rotor as the counterpart material, or the content thereof is 100% by mass of the total friction material. Is less than 0.5% by mass, more preferably less than 0.1% by mass, and even more preferably less than 0.01% by mass.
（チタン酸塩）
　本実施形態の摩擦材は、無機充填材として、チタン酸塩を含有することが好ましい。
　チタン酸塩はモース硬度が約４と低く、融点が１０００℃以上と比較的高いため、高速高温制動時に摩擦界面に介在することで摩擦材の摩耗増大を低減することができる。
　チタン酸塩としては、６チタン酸カリウム、８チタン酸カリウム、チタン酸リチウムカリウム、チタン酸マグネシウムカリウム、チタン酸ナトリウム等が挙げられる。これらの中でも、低速低温制動域の摩擦係数の安定性の観点から、６チタン酸カリウム、８チタン酸カリウムが好ましい。
　チタン酸塩は、１種を単独で用いてもよく、２種以上を併用してもよいが、高速高温制動時の耐摩耗性の観点から、１種類のチタン酸塩を単独で用いることが好ましい。 (Titanate)
The friction material of this embodiment preferably contains titanate as an inorganic filler.
Since titanate has a low Mohs hardness of about 4 and a relatively high melting point of 1000 ° C. or higher, an increase in wear of the friction material can be reduced by interposing at the friction interface during high-speed high-temperature braking.
Examples of titanates include 6 potassium titanate, 8 potassium titanate, lithium potassium titanate, magnesium potassium titanate, and sodium titanate. Of these, potassium hexatitanate and potassium potassium titanate are preferable from the viewpoint of the stability of the friction coefficient in the low-speed low-temperature braking region.
One titanate may be used alone, or two or more may be used in combination. From the viewpoint of wear resistance during high-speed high-temperature braking, one type of titanate may be used alone. preferable.
　チタン酸塩は、人体有害性の観点から、針状ではないものが好ましい。すなわち、本実施形態の摩擦材は、非針状のチタン酸塩を含有することが好ましい。非針状のチタン酸塩とは、多角形、円、楕円等の形状を呈する板状チタン酸塩、不定形状のチタン酸塩などを意味する。
　チタン酸塩の平均粒子径は、２～５０μｍが好ましく、２．２～４０μｍがより好ましく、２．５～３０μｍがさらに好ましい。
　なお、本明細書中における平均粒子径とは、特に断らない限り、メジアン径（Ｄ５０）を意味し、レーザー回折粒度分布測定等の方法を用いて測定することができる。測定装置としては、例えば、レーザー回折／散乱式粒子径分布測定装置、商品名：ＬＡ－９２０（株式会社堀場製作所製）を用いることができる。また、ＪＩＳＢ ４１３０等に代表されるふるい分級によって測定することもできる。 The titanate is preferably not acicular from the viewpoint of human harm. That is, it is preferable that the friction material of this embodiment contains non-acicular titanate. A non-acicular titanate means a plate-like titanate having a polygonal shape, a circle shape, an ellipse shape, or the like, or an indefinite shape titanate.
The average particle size of titanate is preferably 2 to 50 μm, more preferably 2.2 to 40 μm, and even more preferably 2.5 to 30 μm.
The average particle diameter in the present specification means the median diameter (D 50 ) unless otherwise specified, and can be measured using a method such as laser diffraction particle size distribution measurement. As the measuring device, for example, a laser diffraction / scattering particle size distribution measuring device, trade name: LA-920 (manufactured by Horiba, Ltd.) can be used. Moreover, it can also measure by sieve classification represented by JISB4130.
　本実施形態の摩擦材がチタン酸塩を含有する場合、その含有量は、摩擦材全量１００質量％に対して、１５～２５質量％が好ましく、１５～２２質量％がより好ましく、１５～２０質量％がさらに好ましい。チタン酸塩の含有量が、上記下限値以上であると、高速高温制動時の耐摩耗性に優れ、十分な摩擦係数保持の効果が得られ、上記上限値以下であると、低速低温制動域における摩擦係数の低下を抑制することができる。
　本実施形態の摩擦材は、摩擦係数の安定性の観点から、非針状であって平均粒子径が２～５０μｍのチタン酸塩を、摩擦材全量１００質量％に対して、１５～２５質量％含有することが特に好ましい。 When the friction material of this embodiment contains titanate, the content thereof is preferably 15 to 25% by mass, more preferably 15 to 22% by mass, and more preferably 15 to 20% with respect to 100% by mass of the total friction material. More preferred is mass%. When the titanate content is equal to or higher than the above lower limit value, excellent wear resistance during high-speed high-temperature braking is obtained, and a sufficient friction coefficient retention effect is obtained. It is possible to suppress a decrease in the friction coefficient.
In the friction material of this embodiment, from the viewpoint of the stability of the friction coefficient, non-acicular titanate having an average particle diameter of 2 to 50 μm is 15 to 25 mass with respect to 100 mass% of the total friction material. % Content is particularly preferable.
（ウォラストナイト）
　ウォラストナイトは、ＣａＳｉＯ３で示されるケイ酸塩鉱物であり、例えば、針状又は長柱状の形状を有するものである。
　ウォラストナイトの平均アスペクト比（平均長さ／平均径又は厚さ）は３以上が好ましく、４～１２がより好ましく、５～８がさらに好ましい。平均アスペクト比が３以上であると、摩擦材の常温及び高温におけるせん断強度並びに耐クラック性を効果的に向上させることができる。ここで、平均アスペクト比は、Ｄ５０値（体積分布の累積中央値）を意味し、例えば、動的画像解析法により測定することができる。
　ウォラストナイトの平均長さは、摩擦材への強度付与の観点から、１００～５００μｍが好ましく、１５０～４５０μｍがより好ましく、２００～４００μｍがさらに好ましい。
　本実施形態の摩擦材がウォラストナイトを含有する場合、その含有量は、摩擦材全量１００質量％に対して、２～１０質量％が好ましく、３～８質量％がより好ましく、４～７質量％がさらに好ましい。 (Wollastonite)
Wollastonite is a silicate mineral represented by CaSiO 3 and has, for example, a needle shape or a long column shape.
The average aspect ratio (average length / average diameter or thickness) of wollastonite is preferably 3 or more, more preferably 4 to 12, and still more preferably 5 to 8. When the average aspect ratio is 3 or more, the shear strength and crack resistance of the friction material at normal temperature and high temperature can be effectively improved. The average aspect ratio refers to D 50 value (cumulative median of the volume distribution), for example, it can be measured by a dynamic image analysis method.
The average length of wollastonite is preferably 100 to 500 μm, more preferably 150 to 450 μm, and even more preferably 200 to 400 μm from the viewpoint of imparting strength to the friction material.
When the friction material of this embodiment contains wollastonite, the content thereof is preferably 2 to 10% by mass, more preferably 3 to 8% by mass with respect to 100% by mass of the total friction material, and 4 to 7 More preferred is mass%.
（研削材）
　本実施形態の摩擦材は、研削材として、珪酸ジルコニウム、四酸化三鉄、二酸化三鉄、酸化ビスマス、酸化ジルコニウム等を含有していてもよい。これらの中でも、珪酸ジルコニウム、酸化ジルコニウムが好ましい。 (Grinding material)
The friction material of this embodiment may contain zirconium silicate, triiron tetraoxide, triiron dioxide, bismuth oxide, zirconium oxide, or the like as an abrasive. Among these, zirconium silicate and zirconium oxide are preferable.
　珪酸ジルコニウムは、モース硬度が６～７．５と高く、研削による摩擦係数の発現に効果的である。
　珪酸ジルコニウムの平均粒子径は、０．２～２μｍが好ましく、０．３～２μｍがより好ましく、０．４～２μｍがさらに好ましい。
　本実施形態の摩擦材が珪酸ジルコニウムを含有する場合、その含有量は、摩擦材全量１００質量％に対して、４～１０質量％が好ましく、５～１０質量％がより好ましい。
　本実施形態の摩擦材は、摩擦係数の安定性の観点から、平均粒子径が０．４～２μｍの珪酸ジルコニウムを、摩擦材全量１００質量％に対して、４～１０質量％含有することが特に好ましい。
　なお、本実施形態の摩擦材は、所望する性能に応じて、珪酸ジルコニウムを含有しないものであってもよい。 Zirconium silicate has a high Mohs hardness of 6 to 7.5 and is effective in developing a friction coefficient by grinding.
The average particle size of zirconium silicate is preferably 0.2 to 2 μm, more preferably 0.3 to 2 μm, and further preferably 0.4 to 2 μm.
When the friction material of this embodiment contains zirconium silicate, the content thereof is preferably 4 to 10% by mass and more preferably 5 to 10% by mass with respect to 100% by mass of the total friction material.
From the viewpoint of stability of the friction coefficient, the friction material of this embodiment may contain 4 to 10% by mass of zirconium silicate having an average particle size of 0.4 to 2 μm with respect to 100% by mass of the total friction material. Particularly preferred.
In addition, the friction material of this embodiment may not contain a zirconium silicate according to the desired performance.
　酸化ジルコニウムの平均粒子径は、１～１４μｍが好ましく、５～１０μｍがより好ましく、８～９μｍがさらに好ましい。
　本実施形態の摩擦材が酸化ジルコニウムを含有する場合、その含有量は、摩擦材全量１００質量％に対して、１０～２０質量％が好ましく、１２～１９質量％がより好ましく、１４～１８質量％がさらに好ましい。酸化ジルコニウムの含有量が上記下限値以上であると、高速高温制動時の耐摩耗性に優れ、十分な摩擦係数保持の効果が得られ、上記上限値以下であると、低速低温制動域における摩擦係数の低下を抑制することができる。 The average particle diameter of zirconium oxide is preferably 1 to 14 μm, more preferably 5 to 10 μm, and still more preferably 8 to 9 μm.
When the friction material of this embodiment contains zirconium oxide, the content thereof is preferably 10 to 20% by mass, more preferably 12 to 19% by mass, and more preferably 14 to 18% by mass with respect to 100% by mass of the total friction material. % Is more preferable. When the content of zirconium oxide is not less than the above lower limit value, it has excellent wear resistance during high-speed high-temperature braking, and a sufficient friction coefficient retention effect is obtained. A decrease in coefficient can be suppressed.
（黒鉛）
　本実施形態の摩擦材は黒鉛を含有することが好ましい。黒鉛を含有することで摩擦材により優れた熱伝導率を付与できる。
　黒鉛の平均粒子径は、１００～６００μｍが好ましく、２００～４５０μｍがより好ましく、３００～３５０μｍがさらに好ましい。また、黒鉛の平均粒子径は、所望する熱伝導率に応じて、１０～９０μｍであってもよく、２０～６０μｍであってもよい。黒鉛は、異なる平均粒子径を有するものを２種以上組み合わせて用いてもよく、例えば、平均粒子径が１００～６００μｍ、好ましくは２００～４５０μｍの黒鉛（I）と、平均粒子径が１０～９０μｍ、好ましくは２０～６０μｍである黒鉛（II）とを、質量比（黒鉛（I）／黒鉛（II））が０．５～５、好ましくは１～２の範囲で使用してもよい。
　本実施形態の摩擦材が黒鉛を含有する場合、その合計含有量は、摩擦材全量１００質量％に対して、０．５～１０質量％が好ましく、１～５質量％がより好ましく、２～４質量％がさらに好ましい。
　黒鉛の平均粒子径及び合計含有量が上記範囲であると、良好な摩擦材への熱伝導率の付与と摩擦係数の保持とを両立することができる。 (graphite)
The friction material of the present embodiment preferably contains graphite. By containing graphite, excellent thermal conductivity can be imparted to the friction material.
The average particle diameter of graphite is preferably 100 to 600 μm, more preferably 200 to 450 μm, and further preferably 300 to 350 μm. The average particle diameter of graphite may be 10 to 90 μm or 20 to 60 μm depending on the desired thermal conductivity. Two or more types of graphite having different average particle sizes may be used in combination. For example, graphite (I) having an average particle size of 100 to 600 μm, preferably 200 to 450 μm, and an average particle size of 10 to 90 μm. Further, graphite (II), preferably 20 to 60 μm, may be used in a mass ratio (graphite (I) / graphite (II)) of 0.5 to 5, preferably 1 to 2.
When the friction material of this embodiment contains graphite, the total content is preferably 0.5 to 10% by mass, more preferably 1 to 5% by mass, and more preferably 2 to More preferably, 4% by mass.
When the average particle diameter and the total content of graphite are within the above ranges, it is possible to achieve both good thermal conductivity imparting to the friction material and retention of the friction coefficient.
（その他の無機充填材）
　その他の無機充填材としては、酸化マグネシウム、三硫化アンチモン、水酸化ジルコニウム、硫化錫、二硫化モリブデン、硫化ビスマス、硫化亜鉛、硫化鉄、水酸化カルシウム、酸化カルシウム、炭酸ナトリウム、炭酸カルシウム、炭酸マグネシウム、硫酸バリウム、コークス、γアルミナ、αアルミナ、マイカ、バーミキュライト、硫酸カルシウム、ムライト、クロマイト、酸化チタン、シリカ等が挙げられる。これらの中でも、三硫化アンチモン、硫化錫、マイカ、水酸化カルシウム、硫酸バリウムが好ましい。これらのその他の無機充填材は、摩擦材に使用されている一般的なものを使用することができる。 (Other inorganic fillers)
Other inorganic fillers include magnesium oxide, antimony trisulfide, zirconium hydroxide, tin sulfide, molybdenum disulfide, bismuth sulfide, zinc sulfide, iron sulfide, calcium hydroxide, calcium oxide, sodium carbonate, calcium carbonate, magnesium carbonate , Barium sulfate, coke, γ alumina, α alumina, mica, vermiculite, calcium sulfate, mullite, chromite, titanium oxide, silica and the like. Among these, antimony trisulfide, tin sulfide, mica, calcium hydroxide, and barium sulfate are preferable. As these other inorganic fillers, general materials used for friction materials can be used.
　本実施形態の摩擦材が硫化錫を含有する場合、その含有量は、摩擦材全量１００質量％に対して、０．５～５質量％が好ましく、１．５～３質量％がより好ましい。
　硫化錫の平均粒子径は、１００～８００μｍが好ましく、２００～７００μｍがより好ましく、２５０～６５０μｍがさらに好ましい。
　本実施形態の摩擦材が三硫化アンチモンを含有する場合、その含有量は、摩擦材全量１００質量％に対して、０．２～４質量％が好ましく、１．０～２質量％がより好ましい。
　三硫化アンチモンの平均粒子径は、１０～３００μｍが好ましく、２０～２００μｍがより好ましく、３０～１７０μｍがさらに好ましい。
　本実施形態の摩擦材がマイカを含有する場合、その含有量は、摩擦材全量１００質量％に対して、１～１０質量％が好ましく、３～７質量％がより好ましい。
　マイカの平均粒子径は、５～１００μｍが好ましく、１０～６０μｍがより好ましく、１２～２０μｍがさらに好ましい。
　本実施形態の摩擦材が水酸化カルシウムを含有する場合、その含有量は、摩擦材全量１００質量％に対して、０．０１～１質量％が好ましく、０．０５～０．３質量％がより好ましい。
　水酸化カルシウムの平均粒子径は、１０～３００μｍが好ましく、３０～２００μｍがより好ましく、５０～１００μｍがさらに好ましい。
　本実施形態の摩擦材が硫酸バリウムを含有する場合、その含有量は、摩擦材全量１００質量％に対して、５～２０質量％が好ましく、８～１２質量％がより好ましい。
　硫酸バリウムの平均粒子径は、１～５０μｍが好ましく、３～３０μｍがより好ましく、５～２０μｍがさらに好ましい。
　本実施形態の摩擦材が、その他の無機充填材を含有する場合、その合計含有量は、摩擦材全量１００質量％に対して、１２～５０質量％が好ましく、１５～４０質量％がより好ましく、２０～３５質量％がさらに好ましい。 When the friction material of this embodiment contains tin sulfide, the content thereof is preferably 0.5 to 5% by mass and more preferably 1.5 to 3% by mass with respect to 100% by mass of the total friction material.
The average particle diameter of tin sulfide is preferably 100 to 800 μm, more preferably 200 to 700 μm, and further preferably 250 to 650 μm.
When the friction material of this embodiment contains antimony trisulfide, the content thereof is preferably 0.2 to 4% by mass and more preferably 1.0 to 2% by mass with respect to 100% by mass of the total amount of the friction material. .
The average particle size of antimony trisulfide is preferably 10 to 300 μm, more preferably 20 to 200 μm, and even more preferably 30 to 170 μm.
When the friction material of this embodiment contains mica, the content is preferably 1 to 10% by mass and more preferably 3 to 7% by mass with respect to 100% by mass of the total friction material.
The average particle diameter of mica is preferably 5 to 100 μm, more preferably 10 to 60 μm, and further preferably 12 to 20 μm.
When the friction material of this embodiment contains calcium hydroxide, the content thereof is preferably 0.01 to 1% by mass, and 0.05 to 0.3% by mass with respect to 100% by mass of the total friction material. More preferred.
The average particle size of calcium hydroxide is preferably 10 to 300 μm, more preferably 30 to 200 μm, and still more preferably 50 to 100 μm.
When the friction material of this embodiment contains barium sulfate, the content thereof is preferably 5 to 20% by mass and more preferably 8 to 12% by mass with respect to 100% by mass of the total friction material.
The average particle diameter of barium sulfate is preferably 1 to 50 μm, more preferably 3 to 30 μm, and even more preferably 5 to 20 μm.
When the friction material of this embodiment contains other inorganic fillers, the total content thereof is preferably 12 to 50% by mass, more preferably 15 to 40% by mass with respect to 100% by mass of the total friction material. 20 to 35% by mass is more preferable.
　本実施形態の摩擦材中における無機充填材の総含有量は、摩擦材全量１００質量％に対して、５０～８５質量％が好ましく、６０～８０質量％がより好ましく、６５～７５質量％がさらに好ましい。 The total content of the inorganic filler in the friction material of the present embodiment is preferably 50 to 85% by mass, more preferably 60 to 80% by mass, and 65 to 75% by mass with respect to 100% by mass of the total friction material. Further preferred.
＜有機充填材＞
　本実施形態の摩擦材は有機充填材を含有することが好ましい。有機充填材は、摩擦材の音振性能、耐摩耗性等を向上させるための摩擦調整剤として含まれるものである。
　有機充填材は、１種を単独で用いてもよく、２種以上を併用してもよい。
　有機充填材としては、カシューダスト、ゴム成分等が挙げられる。
　カシューダストとしては、例えば、カシューナッツシェルオイルを重合及び硬化させたものを粉砕して得られる、通常、摩擦材に用いられるものであればよい。なお、カシューダストは、未変性のカシューダストであることが好ましい。
　カシューダストの平均粒子径は、５０～６００μｍが好ましく、７０～５５０μｍがより好ましく、１００～５００μｍがさらに好ましい。
　本実施形態の摩擦材がカシューダストを含有する場合、その含有量は、摩擦材全量１００質量％に対して、４～２０質量％が好ましく、８～１６質量％がより好ましく、１０～１４質量％がさらに好ましい。
　カシューダストの含有量が上記範囲であると、摩擦材の低弾性化による鳴き等の音振性能を改善することができる。 <Organic filler>
The friction material of the present embodiment preferably contains an organic filler. The organic filler is included as a friction modifier for improving the sound vibration performance, wear resistance and the like of the friction material.
An organic filler may be used individually by 1 type, and may use 2 or more types together.
Examples of the organic filler include cashew dust and rubber components.
As the cashew dust, for example, any cashew dust can be used as long as it is usually used for a friction material obtained by pulverizing and curing cashew nut shell oil. The cashew dust is preferably unmodified cashew dust.
The average particle size of cashew dust is preferably 50 to 600 μm, more preferably 70 to 550 μm, and still more preferably 100 to 500 μm.
When the friction material of the present embodiment contains cashew dust, the content thereof is preferably 4 to 20% by mass, more preferably 8 to 16% by mass with respect to 100% by mass of the total friction material, and 10 to 14% by mass. % Is more preferable.
When the content of cashew dust is in the above range, sound vibration performance such as squealing due to low elasticity of the friction material can be improved.
　ゴム成分は、摩擦材に使用されている公知のものを使用することができ、タイヤゴム、アクリルゴム、イソプレンゴム、ＮＢＲ（ニトリルブタジエンゴム）、ＳＢＲ（スチレンブタジエンゴム）等が挙げられる。
　本実施形態の摩擦材がゴム成分を含有する場合、その含有量は、摩擦材全量１００質量％に対して、０．２～１０質量％が好ましく、０．５～５質量％がより好ましく、１～３質量％がさらに好ましい。 As the rubber component, known materials used for friction materials can be used, and examples thereof include tire rubber, acrylic rubber, isoprene rubber, NBR (nitrile butadiene rubber), SBR (styrene butadiene rubber) and the like.
When the friction material of the present embodiment contains a rubber component, the content thereof is preferably 0.2 to 10% by mass, more preferably 0.5 to 5% by mass, with respect to 100% by mass of the total friction material. It is more preferably 1 to 3% by mass.
　本実施形態の摩擦材は、カシューダスト及びゴム成分からなる群から選択される１種以上を含有することが好ましく、カシューダストとゴム成分とを併用することがより好ましい。また、カシューダストとゴム成分とを併用する場合には、カシューダストをゴム成分で被覆したものを用いてもよく、音振性能の観点から、カシューダストとゴム成分とを別個に配合してもよい。 The friction material of the present embodiment preferably contains one or more selected from the group consisting of cashew dust and a rubber component, and more preferably used in combination with cashew dust and a rubber component. In addition, when cashew dust and a rubber component are used in combination, the cashew dust coated with the rubber component may be used. From the viewpoint of sound vibration performance, the cashew dust and the rubber component may be blended separately. Good.
　本実施形態の摩擦材が有機充填材を含有する場合、その合計含有量は、摩擦材全量１００質量％に対して、２～２０質量％が好ましく、５～１７質量％がより好ましく、１０～１５質量％がさらに好ましい。
　有機充填材の合計含有量が上記範囲であると、摩擦材の低弾性化による鳴き等の音振性能が改善し、また耐熱性の悪化及び熱履歴による強度低下を避けることができる。 When the friction material of this embodiment contains an organic filler, the total content is preferably 2 to 20% by mass, more preferably 5 to 17% by mass, and more preferably 10 to 10% by mass with respect to 100% by mass of the total friction material. 15 mass% is further more preferable.
When the total content of the organic filler is within the above range, sound vibration performance such as squealing due to low elasticity of the friction material is improved, and deterioration in heat resistance and strength reduction due to thermal history can be avoided.
＜結合材＞
　本実施形態の摩擦材は、さらに、結合材を含有することが好ましい。結合材は、摩擦材に含有される有機充填材、繊維基材等を一体化して、強度を与えるものである。
　結合材は、１種を単独で使用してもよく、２種以上を組み合わせて使用してもよい。
　結合材としては、通常、摩擦材に用いられる熱硬化性樹脂を用いることができる。
　熱硬化性樹脂としては、フェノール樹脂、アクリルゴム変性フェノール樹脂、シリコーン変性フェノール樹脂、カシュー変性フェノール樹脂、エポキシ変性フェノール樹脂、アルキルベンゼン変性フェノール樹脂等の各種変性フェノール樹脂などが挙げられる。これらの中でも、摩擦界面の撥水性を高めることができる観点から、シリコーン変性フェノール樹脂が好ましい。シリコーン変性フェノール樹脂としては、シリコーンオイル又はシリコーンゴムを分散させたフェノール樹脂が好ましい。シリコーン変性フェノール樹脂は単独で使用してもよいが、上記したシリコーン変性フェノール樹脂以外の熱硬化性樹脂と併用してもよく、アクリルゴム変性フェノール樹脂と併用することが好ましい。
　シリコーン変性フェノール樹脂とアクリルゴム変性フェノール樹脂とを併用する場合、その含有量比〔シリコーン変性フェノール樹脂：アクリルゴム変性フェノール樹脂〕は、質量比で、２０：８０～８０：２０が好ましく、３０：７０～７０：３０がより好ましく、４０：６０～６０：４０がさらに好ましい。 <Binder>
The friction material of this embodiment preferably further contains a binder. The binding material provides strength by integrating an organic filler, a fiber base material, and the like contained in the friction material.
A binder may be used individually by 1 type and may be used in combination of 2 or more type.
As the binder, a thermosetting resin usually used for a friction material can be used.
Examples of the thermosetting resin include various modified phenol resins such as phenol resin, acrylic rubber-modified phenol resin, silicone-modified phenol resin, cashew-modified phenol resin, epoxy-modified phenol resin, and alkylbenzene-modified phenol resin. Among these, a silicone-modified phenol resin is preferable from the viewpoint of improving the water repellency at the friction interface. As the silicone-modified phenol resin, a phenol resin in which silicone oil or silicone rubber is dispersed is preferable. The silicone-modified phenol resin may be used alone, but may be used in combination with a thermosetting resin other than the above-described silicone-modified phenol resin, and is preferably used in combination with an acrylic rubber-modified phenol resin.
When the silicone-modified phenol resin and the acrylic rubber-modified phenol resin are used in combination, the content ratio [silicone-modified phenol resin: acrylic rubber-modified phenol resin] is preferably 20:80 to 80:20, and preferably 30: 70 to 70:30 is more preferable, and 40:60 to 60:40 is even more preferable.
　本実施形態の摩擦材中における結合材の合計含有量は、摩擦材全量１００質量％に対して、４～１４質量％が好ましく、６～１２質量％がより好ましく、８～１０質量％がさらに好ましい。
　結合材の合計含有量が上記範囲であると、摩擦材の強度低下をより抑制でき、また、摩擦材の気孔率が減少し、弾性率が高くなることによる鳴き等の音振性能悪化を抑制できる。 The total content of the binder in the friction material of the present embodiment is preferably 4 to 14% by mass, more preferably 6 to 12% by mass, and further more preferably 8 to 10% by mass with respect to 100% by mass of the total friction material. preferable.
When the total content of the binder is in the above range, the strength of the friction material can be further prevented from lowering, and the porosity of the friction material is reduced and the deterioration of sound vibration performance such as squeal due to the increased elastic modulus is suppressed. it can.
＜その他の成分＞
　本実施形態の摩擦材は、必要に応じて、上記各成分以外のその他の材料を含有していてもよい。 <Other ingredients>
The friction material of the present embodiment may contain other materials other than the above components as necessary.
＜摩擦材の製造方法＞
　本実施形態の摩擦材は、一般に使用されている方法により製造することができる。
　本実施形態の摩擦材の製造方法としては、例えば、本実施形態の摩擦材の組成を充足する摩擦材組成物を加熱加圧成形して製造する方法が挙げられる。詳細には、例えば、後述する本実施形態の摩擦材組成物を、レーディゲ（登録商標）ミキサー、加圧ニーダー、アイリッヒ（登録商標）ミキサー等の混合機を用いて均一に混合し、この混合物を成形金型にて予備成形し、得られた予備成形物を成形温度１４０～１５０℃、成形圧力３０～４５ＭＰａ、成形時間３～６分間の条件で成形し、得られた成形物を１８０～２１０℃で３～４時間熱処理する方法が挙げられる。なお、必要に応じて塗装、スコーチ処理、研磨処理等を行ってもよい。 <Friction material manufacturing method>
The friction material of this embodiment can be manufactured by a generally used method.
As a manufacturing method of the friction material of this embodiment, the method of heat-pressing and manufacturing the friction material composition which satisfies the composition of the friction material of this embodiment is mentioned, for example. Specifically, for example, the friction material composition of the present embodiment to be described later is uniformly mixed using a mixer such as a Laedige (registered trademark) mixer, a pressure kneader, an Eirich (registered trademark) mixer, and the mixture is mixed. Preliminary molding is performed with a molding die, and the obtained preform is molded under conditions of a molding temperature of 140 to 150 ° C., a molding pressure of 30 to 45 MPa, and a molding time of 3 to 6 minutes. A heat treatment method at 3 ° C. for 3 to 4 hours can be mentioned. In addition, you may perform a coating, a scorch process, a grinding | polishing process, etc. as needed.
＜摩擦材の用途＞
　本実施形態の摩擦材は、例えば、下記（１）～（３）の態様で用いられる。
（１）摩擦材のみの構成
（２）裏金と、該裏金の上に形成させた、摩擦面となる本実施形態の摩擦材とを有する摩擦部材
（３）上記（２）の構成において、裏金と摩擦部材との間に、裏金の接着効果を高めるための表面改質を目的としたプライマー層、裏金と摩擦部材の接着を目的とした接着層をさらに介在させた構成
　これらの中でも、上記（２）又は（３）のように、本実施形態の摩擦材と裏金とを一体化してなる摩擦部材として用いられることが好ましい。
　上記裏金は、摩擦部材の機械的強度の向上のために用いるものであり、その材質としては、鉄、ステンレス等の金属；無機繊維強化プラスチック、炭素繊維強化プラスチック等の繊維強化プラスチックなどが挙げられる。
　上記プライマー層及び接着層としては、通常、ブレーキシュー等の摩擦部材に用いられるものであればよい。 <Application of friction material>
The friction material of this embodiment is used in the following aspects (1) to (3), for example.
(1) Friction material only configuration (2) Friction member having a back metal and the friction material of the present embodiment to be a friction surface formed on the back metal (3) In the above configuration (2), the back metal A structure in which a primer layer for the purpose of surface modification for enhancing the adhesion effect of the backing metal and an adhesive layer for the purpose of bonding the backing metal and the friction member are further interposed between the friction member and the friction member. As in (2) or (3), it is preferable to be used as a friction member formed by integrating the friction material and the back metal of the present embodiment.
The backing metal is used to improve the mechanical strength of the friction member. Examples of the material include metals such as iron and stainless steel; fiber reinforced plastics such as inorganic fiber reinforced plastics and carbon fiber reinforced plastics. .
The primer layer and the adhesive layer may be those used for friction members such as brake shoes.
　本実施形態の摩擦材は、自動車等のディスクブレーキパッド、ブレーキライニング等の摩擦材として好適である。また、本実施形態の摩擦材は、目的形状に成形、加工、貼り付け等の工程を施すことにより、クラッチフェーシング、電磁ブレーキ、保持ブレーキ等の摩擦材としても使用することができる。
　さらに、本実施形態の摩擦材は、低速低温制動域において安定した摩擦係数を発現できることから、回生ブレーキ等の制御ブレーキに搭載される乗用車用ブレーキパッドに好適である。すなわち、本発明によると、本実施形態の摩擦材を用いた制御ブレーキを搭載した、電気自動車、ハイブリッド自動車等の乗用車をも提供することができる。
　さらに、本実施形態の摩擦材は、摩擦係数の安定性、高温での耐摩耗性等に優れるため、ディスクブレーキパッド、ブレーキライニング等の摩擦部材の「上張り材」として有用であり、さらに摩擦部材の「下張り材」として成形して用いることもできる。なお、「上張り材」とは、摩擦部材の摩擦面となる摩擦材であり、「下張り材」とは、摩擦部材の摩擦面となる摩擦材と裏金との間に介在する、摩擦材と裏金との接着部付近の剪断強度、耐クラック性向上を目的とした層のことである。 The friction material of this embodiment is suitable as a friction material for disc brake pads and brake linings for automobiles. Moreover, the friction material of this embodiment can be used also as friction materials, such as a clutch facing, an electromagnetic brake, a holding brake, by giving processes, such as a shaping | molding, a process, and a sticking, to a target shape.
Furthermore, the friction material of this embodiment is suitable for a brake pad for a passenger car mounted on a control brake such as a regenerative brake because it can exhibit a stable friction coefficient in a low-speed low-temperature braking region. That is, according to the present invention, it is possible to provide a passenger vehicle such as an electric vehicle or a hybrid vehicle equipped with a control brake using the friction material of the present embodiment.
Furthermore, since the friction material of the present embodiment is excellent in stability of friction coefficient, wear resistance at high temperature, etc., it is useful as a “upholstery material” for friction members such as disc brake pads and brake linings. It can also be molded and used as a “underlaying material” for the member. The “upper material” is a friction material that becomes the friction surface of the friction member, and the “underlay material” is a friction material that is interposed between the friction material that becomes the friction surface of the friction member and the back metal. It is a layer for the purpose of improving the shear strength and crack resistance in the vicinity of the adhesion part with the back metal.
［摩擦材組成物］
　本実施形態に係る摩擦材組成物は、銅を含まない、又は含んでいてもその含有量が、銅元素として０．５質量％以下の摩擦材組成物であり、無機繊維（Ｘ１）と該無機繊維（Ｘ１）のショット（Ｘ２）とを含有し、前記ショット（Ｘ２）の含有量が、無機繊維（Ｘ１）及びショット（Ｘ２）の総量中、０．２質量％以上である、摩擦材組成物である。
　本実施形態の摩擦材組成物に含有される各成分の種類、及びその製造方法は、上記本実施形態の摩擦材と同様に説明されるものであり、その好適な態様もすべて同じである。なお、摩擦材組成物中における各成分の含有量の好適範囲は、本実施形態の摩擦材で説明した好適範囲と同じであるが、含有量の基準は「摩擦材組成物全量１００質量％」とする。
　さらに、本発明は本実施形態の摩擦材組成物を成形してなる摩擦材も提供する。本実施形態の摩擦材組成物を成形してなる摩擦材は、例えば、本実施形態の摩擦材組成物を予備成形した予備成形体を熱圧成形する方法、本実施形態の摩擦材組成物を直接熱圧成形し、必要に応じて熱処理を施して結合材を熱硬化する方法等によって製造することができる。具体的な製造方法は、上記本実施形態の摩擦材の製造方法及び後述する実施例に記載の通りである。 [Friction material composition]
The friction material composition according to the present embodiment does not contain copper, or even if it contains copper, the content of the friction material composition is 0.5 mass% or less as a copper element, and the inorganic fiber (X1) and the Friction material which contains shot (X2) of inorganic fiber (X1), and content of said shot (X2) is 0.2 mass% or more in the total amount of inorganic fiber (X1) and shot (X2) It is a composition.
The kind of each component contained in the friction material composition of this embodiment, and its manufacturing method are demonstrated similarly to the friction material of the said embodiment, The suitable aspect is altogether the same. In addition, the preferable range of the content of each component in the friction material composition is the same as the preferable range described in the friction material of the present embodiment, but the reference of the content is “100% by mass of the total friction material composition”. And
Furthermore, this invention also provides the friction material formed by shape | molding the friction material composition of this embodiment. The friction material formed by molding the friction material composition of the present embodiment includes, for example, a method of hot-pressing a preform formed by preforming the friction material composition of the present embodiment, and the friction material composition of the present embodiment. It can be produced by a method such as direct hot pressing, heat treatment as necessary, and thermosetting the binder. The specific manufacturing method is as described in the manufacturing method of the friction material of the present embodiment and the examples described later.
［車両］
　本実施形態の車両は、本実施形態の摩擦部材を搭載した車両である。
　本実施形態の車両としては、本実施形態の摩擦部材を、ディスクブレーキパッド、ブレーキライニング、クラッチフェーシング、電磁ブレーキ、保持ブレーキ等に用いた車両等が挙げられる。車両としては、大型自動車、中型自動車、普通自動車、大型特殊自動車、小型特殊自動車、大型自動二輪車、普通自動二輪車等の自動車が挙げられる。
　本実施形態の摩擦部材を搭載した車両としては、低負荷での制動においても優れた錆取り性を発現できることから、回生ブレーキシステムを搭載した電気自動車及びハイブリッド自動車等の乗用車が特に好適である。 [vehicle]
The vehicle of this embodiment is a vehicle equipped with the friction member of this embodiment.
Examples of the vehicle according to the present embodiment include a vehicle in which the friction member according to the present embodiment is used for a disc brake pad, a brake lining, a clutch facing, an electromagnetic brake, a holding brake, and the like. Examples of the vehicle include large vehicles, medium-sized vehicles, ordinary vehicles, large special vehicles, small special vehicles, large motorcycles, ordinary motorcycles, and the like.
As a vehicle equipped with the friction member of the present embodiment, passenger cars such as electric vehicles and hybrid vehicles equipped with a regenerative braking system are particularly suitable because they can exhibit excellent rust removing properties even in braking at low loads.
　以下、実施例により本実施形態の摩擦材及び摩擦材組成物をさらに詳細に説明するが、本発明は何らこれらに限定されるものではない。 Hereinafter, the friction material and the friction material composition of the present embodiment will be described in more detail by way of examples, but the present invention is not limited to these.
＜実施例１～４及び比較例１～２＞
［ディスクブレーキパッドの作製］
　表１に示す配合量（質量％）にしたがって材料を配合し、実施例１～４及び比較例１～２の摩擦材組成物を得た。
　次に、この摩擦材組成物をレーディゲ（登録商標）ミキサー（株式会社マツボー製、商品名：レーディゲミキサーＭ２０）で混合し、この混合物を成形プレス（王子機械工業株式会社製）で予備成形した。次いで、得られた予備成形物を成形温度１５０℃、成形圧力３０ＭＰａ、成形時間５分間の条件で成形プレス（三起精工株式会社製）を用いて、日立オートモティブシステムズ株式会社製の裏金（鉄製）とともに加熱加圧成形した。続いて、得られた成形品を２００℃で４時間熱処理し、ロータリー研磨機を用いて研磨し、５００℃のスコーチ処理を行って、ディスクブレーキパッド（摩擦材の厚さ９ｍｍ、摩擦材投影面積５２ｃｍ２）を得た。 <Examples 1 to 4 and Comparative Examples 1 and 2>
[Production of disc brake pads]
The materials were blended according to the blending amounts (% by mass) shown in Table 1, and the friction material compositions of Examples 1 to 4 and Comparative Examples 1 to 2 were obtained.
Next, the friction material composition is mixed with a Ladige (registered trademark) mixer (manufactured by Matsubo Co., Ltd., trade name: Ladige mixer M20), and the mixture is preformed with a molding press (manufactured by Oji Machinery Co., Ltd.). did. Next, the obtained preform is molded using a molding press (manufactured by Sanki Seiko Co., Ltd.) under the conditions of a molding temperature of 150 ° C., a molding pressure of 30 MPa, and a molding time of 5 minutes, and a backing metal (manufactured by Hitachi Automotive Systems). Together with heating and pressing. Subsequently, the obtained molded product was heat-treated at 200 ° C. for 4 hours, polished using a rotary polishing machine, subjected to scorch treatment at 500 ° C., and a disc brake pad (friction material thickness 9 mm, friction material projected area). 52 cm 2 ) was obtained.
　なお、実施例及び比較例において使用した各種材料の詳細は以下の通りである。
　以下の説明及び表１において、単に「ショット含有量」と記載する場合は、無機繊維（Ｘ１）及びショット（Ｘ２）の総量中におけるショット（Ｘ２）の含有量（質量％）を意味するものとし、「摩擦材中のショット含有量」とは、摩擦材総量１００質量％に対するショット（Ｘ２）の含有量（質量％）を意味するものとする。 In addition, the detail of the various materials used in the Example and the comparative example is as follows.
In the following description and Table 1, when simply described as “shot content”, it means the content (mass%) of shot (X2) in the total amount of inorganic fibers (X1) and shot (X2). The “shot content in the friction material” means the content (mass%) of the shot (X2) with respect to 100 mass% of the total friction material.
［結合材］
・樹脂Ａ：シリコーン変性フェノール樹脂（住友ベークライト株式会社製　ＰＲ５４５２９）
・樹脂Ｂ：アクリルゴム変性フェノール樹脂（住友ベークライト株式会社製　ＰＲ５５２９１Ａ） [Binder]
Resin A: Silicone-modified phenolic resin (PR54529 manufactured by Sumitomo Bakelite Co., Ltd.)
Resin B: Acrylic rubber modified phenolic resin (PR55291A manufactured by Sumitomo Bakelite Co., Ltd.)
［有機充填材］
・カシューダストＡ：黒系カシューダスト、平均粒子径１５０～５００μｍ
・カシューダストＢ：シリコーンゴムコートカシューダスト、平均粒子径１５０～５００μｍ
・ゴム成分（タイヤゴム粉）：株式会社カークエスト製 粉末ＴＰＡ [Organic filler]
Cashew dust A: Black cashew dust, average particle size 150-500μm
Cashew dust B: Silicone rubber coated cashew dust, average particle size 150-500 μm
・ Rubber component (tire rubber powder): Powder TPA manufactured by Carquest Co., Ltd.
［繊維基材］
・銅繊維：平均繊維長３０００μｍ
・アラミド繊維：平均繊維長１１７０μｍ
・鉱物繊維Ａ：生体溶解性を有する鉱物繊維
　　　ショット含有量：０．１質量％
　　　平均繊維長：２３０±５０μｍ
　　　平均繊維径：５．５μｍ
　　　組成：ＣａＯ（２１．３質量％）、ＭｇＯ（６．０質量％）、ＳｉＯ２（４２．５質量％）、Ａｌ２Ｏ３（１８．０質量％）、ＴｉＯ２（１．５質量％）、Ｆｅ２Ｏ３（７．９質量％）、Ｎａ２Ｏ（２．０質量％）、Ｋ２Ｏ（０．５質量％）、Ｐ２Ｏ５（０．２質量％）、ＭｎＯ（０．１質量％）
・鉱物繊維Ｂ：生体溶解性を有する鉱物繊維
　　　ショット含有量：０．２質量％
　　　平均繊維長：６５０±１５０μｍ
　　　平均繊維径：５．５μｍ
　　　組成：ＣａＯ（２１．３質量％）、ＭｇＯ（６．０質量％）、ＳｉＯ２（４２．５質量％）、Ａｌ２Ｏ３（１８．０質量％）、ＴｉＯ２（１．５質量％）、Ｆｅ２Ｏ３（７．９質量％）、Ｎａ２Ｏ（２．０質量％）、Ｋ２Ｏ（０．５質量％）、Ｐ２Ｏ５（０．２質量％）、ＭｎＯ（０．１質量％）
・鉱物繊維Ｃ：生体溶解性を有する鉱物繊維
　　　ショット含有量：１質量％
　　　平均繊維長：１２５±２５μｍ
　　　平均繊維径：５．５μｍ
　　　組成：ＣａＯ（２１．３質量％）、ＭｇＯ（６．０質量％）、ＳｉＯ２（４２．５質量％）、Ａｌ２Ｏ３（１８．０質量％）、ＴｉＯ２（１．５質量％）、Ｆｅ２Ｏ３（７．９質量％）、Ｎａ２Ｏ（２．０質量％）、Ｋ２Ｏ（０．５質量％）、Ｐ２Ｏ５（０．２質量％）、ＭｎＯ（０．１質量％）
・鉱物繊維Ｄ：生体溶解性を有する鉱物繊維
　　　ショット含有量：５質量％
　　　平均繊維長：１２５±２５μｍ
　　　平均繊維径：５．５μｍ
　　　組成：ＣａＯ（２１．３質量％）、ＭｇＯ（６．０質量％）、ＳｉＯ２（４２．５質量％）、Ａｌ２Ｏ３（１８．０質量％）、ＴｉＯ２（１．５質量％）、Ｆｅ２Ｏ３（７．９質量％）、Ｎａ２Ｏ（２．０質量％）、Ｋ２Ｏ（０．５質量％）、Ｐ２Ｏ５（０．２質量％）、ＭｎＯ（０．１質量％）
・鉱物繊維Ｅ：生体溶解性を有する鉱物繊維
　　　ショット含有量：１５質量％
　　　平均繊維長：１２５±２５μｍ
　　　平均繊維径：５．５μｍ
　　　組成：ＣａＯ（２１．３質量％）、ＭｇＯ（６．０質量％）、ＳｉＯ２（４２．５質量％）、Ａｌ２Ｏ３（１８．０質量％）、ＴｉＯ２（１．５質量％）、Ｆｅ２Ｏ３（７．９質量％）、Ｎａ２Ｏ（２．０質量％）、Ｋ２Ｏ（０．５質量％）、Ｐ２Ｏ５（０．２質量％）、ＭｎＯ（０．１質量％） [Fiber base]
Copper fiber: Average fiber length 3000 μm
・ Aramid fiber: Average fiber length 1170μm
Mineral fiber A: Mineral fiber having biosolubility Shot content: 0.1% by mass
Average fiber length: 230 ± 50 μm
Average fiber diameter: 5.5 μm
Composition: CaO (21.3 wt%), MgO (6.0 wt%), SiO 2 (42.5 wt%), Al 2 O 3 ( 18.0 wt%), TiO 2 (1.5 wt% ), Fe 2 O 3 (7.9 mass%), Na 2 O (2.0 mass%), K 2 O (0.5 mass%), P 2 O 5 (0.2 mass%), MnO ( 0.1% by mass)
Mineral fiber B: Mineral fiber having biosolubility Shot content: 0.2% by mass
Average fiber length: 650 ± 150 μm
Average fiber diameter: 5.5 μm
Composition: CaO (21.3 wt%), MgO (6.0 wt%), SiO 2 (42.5 wt%), Al 2 O 3 ( 18.0 wt%), TiO 2 (1.5 wt% ), Fe 2 O 3 (7.9 mass%), Na 2 O (2.0 mass%), K 2 O (0.5 mass%), P 2 O 5 (0.2 mass%), MnO ( 0.1% by mass)
・ Mineral fiber C: Mineral fiber having biological solubility Shot content: 1% by mass
Average fiber length: 125 ± 25 μm
Average fiber diameter: 5.5 μm
Composition: CaO (21.3 wt%), MgO (6.0 wt%), SiO 2 (42.5 wt%), Al 2 O 3 ( 18.0 wt%), TiO 2 (1.5 wt% ), Fe 2 O 3 (7.9 mass%), Na 2 O (2.0 mass%), K 2 O (0.5 mass%), P 2 O 5 (0.2 mass%), MnO ( 0.1% by mass)
Mineral fiber D: Mineral fiber having biosolubility Shot content: 5% by mass
Average fiber length: 125 ± 25 μm
Average fiber diameter: 5.5 μm
Composition: CaO (21.3 wt%), MgO (6.0 wt%), SiO 2 (42.5 wt%), Al 2 O 3 ( 18.0 wt%), TiO 2 (1.5 wt% ), Fe 2 O 3 (7.9 mass%), Na 2 O (2.0 mass%), K 2 O (0.5 mass%), P 2 O 5 (0.2 mass%), MnO ( 0.1% by mass)
Mineral fiber E: Mineral fiber having biosolubility Shot content: 15% by mass
Average fiber length: 125 ± 25 μm
Average fiber diameter: 5.5 μm
Composition: CaO (21.3 wt%), MgO (6.0 wt%), SiO 2 (42.5 wt%), Al 2 O 3 ( 18.0 wt%), TiO 2 (1.5 wt% ), Fe 2 O 3 (7.9 mass%), Na 2 O (2.0 mass%), K 2 O (0.5 mass%), P 2 O 5 (0.2 mass%), MnO ( 0.1% by mass)
［無機充填材］
・チタン酸リチウムカリウム：平均粒子径２．５μｍ、形状：板状
・ウォラストナイト：平均長さ３００μｍ、アスペクト比：６
・黒鉛Ａ：平均粒子径３００μｍ
・黒鉛Ｂ：平均粒子径３５～５５μｍ
・酸化ジルコニウム：平均粒子径８～９μｍ
・珪酸ジルコニウム：平均粒子径０．４～０．６μｍ、最大粒子径１．１μｍ（株式会社キンセイマテック製　Ａ－ＰＡＸＵＦ）
・金属硫化物Ａ：硫化錫、平均粒子径３００～６００μｍ
・金属硫化物Ｂ：三硫化アンチモン：平均粒子径５０～１５０μｍ
・マイカ：平均粒子径１６～１７μｍ
・水酸化カルシウム：平均粒子径５０～７０μｍ
・硫酸バリウム：平均粒子径１２．５μｍ [Inorganic filler]
・ Lithium potassium titanate: average particle size 2.5 μm, shape: plate shape, wollastonite: average length 300 μm, aspect ratio: 6
Graphite A: average particle size 300 μm
Graphite B: average particle size 35 to 55 μm
・ Zirconium oxide: Average particle size 8-9μm
・ Zirconium silicate: average particle size 0.4-0.6μm, maximum particle size 1.1μm (A-PAXUF manufactured by Kinsei Matec Co., Ltd.)
Metal sulfide A: tin sulfide, average particle size 300 to 600 μm
Metal sulfide B: antimony trisulfide: average particle size 50 to 150 μm
・ Mica: average particle size 16-17μm
・ Calcium hydroxide: average particle size 50-70μm
Barium sulfate: average particle size 12.5μm
　各例で得たディスクブレーキパッドを、ブレーキダイナモ試験機（新日本特機株式会社製）を用いて各種性能の評価を行った。実験には、一般的なピンスライド式のコレット型キャリパー及び株式会社キリウ製ベンチレーテッドディスクローター（ＦＣ２５０（ねずみ鋳鉄））を用い、５０ｋｇｍ２の慣性モーメントで評価を行った。 Various performances of the disc brake pads obtained in each example were evaluated using a brake dynamo tester (manufactured by Shin Nippon Toki Co., Ltd.). In the experiment, a general pin slide type collet caliper and a ventilated disc rotor (FC250 (gray cast iron)) manufactured by Kiriu Co., Ltd. were used, and the evaluation was performed with an inertia moment of 50 kgm 2 .
［低速低温制動域の摩擦係数安定性、及び一制動中の摩擦係数変動率の評価］
　試験環境は２５℃、湿度３０％の条件で実施し、４０ｋｍ／ｈ、０．１５Ｇの制動を１５００回実施し、制動回数５００回目の摩擦係数から制動回数１５００回目の摩擦係数の変化率を「低速低温制動域での摩擦係数安定性」とし、下記評価基準に基づいて評価した。結果を表１に示す。
（評価基準）
　Ａ：変化率±５％以内
　Ｂ：変化率＋５％超＋１０％以下、又は－１０％以上－５％未満
　Ｃ：変化率１０％超又は－１０％未満 [Evaluation of friction coefficient stability in low-speed low-temperature braking range and coefficient of friction fluctuation during one braking]
The test environment is 25 ° C. and 30% humidity, 40 km / h, 0.15 G braking is performed 1500 times, and the rate of change of the friction coefficient from the 500th braking coefficient to the 1500th braking coefficient is expressed as “ The coefficient of friction stability in the low-speed and low-temperature braking range ”was evaluated based on the following evaluation criteria. The results are shown in Table 1.
(Evaluation criteria)
A: Change rate within ± 5% B: Change rate + 5% + 10% or less, or -10% or more and less than −5% C: Change rate 10% or more and less than −10%
　また、制動回数１５００回目における一制動中の摩擦係数の変動率を「一制動中の摩擦係数変動率」とし、下記算出方法及び下記評価基準に基づいて評価した。結果を表１に示す。
（算出方法）
　一制動中の摩擦係数変動率（％）＝（（時間Ｘ２における摩擦係数－時間Ｘ３における摩擦係数）×１００）/（Ｘ２－Ｘ３）
　制動開始時間（秒）：Ｘ１
　制動終了時間（秒）：Ｘ２
　実制動時間の中点（秒）：Ｘ３＝（Ｘ１＋Ｘ２）/２
（評価基準）
　Ａ：変動率３％以下
　Ｂ：変動率３％超５％以下
　Ｃ：変動率５％を超えるもの Further, the coefficient of friction variation during one braking at the number of braking times of 1500 was defined as “friction coefficient coefficient of variation during one braking”, and evaluation was performed based on the following calculation method and the following evaluation criteria. The results are shown in Table 1.
(Calculation method)
Friction coefficient fluctuation rate during braking (%) = ((friction coefficient at time X2−friction coefficient at time X3) × 100) / (X2−X3)
Braking start time (seconds): X1
Braking end time (seconds): X2
Midpoint of actual braking time (seconds): X3 = (X1 + X2) / 2
(Evaluation criteria)
A: Fluctuation rate 3% or less B: Fluctuation rate 3% or more and 5% or less C: Fluctuation rate 5%
［通常制動域における摩擦係数の評価］
　試験環境は２５℃、湿度３０％の条件で実施し、ＪＡＳＯ　Ｃ４０６に準拠し、第二効力試験における２００ｋｍ／ｈ、０．６Ｇ制動における摩擦係数を計測し、下記評価基準に基づいて評価した。結果を表１に示す。
（評価基準）
　Ａ：０．３８以上、０．４１未満
　Ｂ：０．３５以上、０．３８未満
　Ｃ：０．３５未満 [Evaluation of friction coefficient in normal braking range]
The test environment was implemented under conditions of 25 ° C. and a humidity of 30%, and in accordance with JASO C406, the friction coefficient at 200 km / h, 0.6 G braking in the second efficacy test was measured and evaluated based on the following evaluation criteria. The results are shown in Table 1.
(Evaluation criteria)
A: 0.38 or more, less than 0.41 B: 0.35 or more, less than 0.38 C: less than 0.35
［錆取り性の評価］
　制動初速度６０ｋｍ／ｈ、２．０ＭＰａ制動、制動回数１０００回、制動前ブレーキ温度１００℃の試験条件で、予め表面に錆を発生させたディスクロータの錆の研削程度を下記基準に基づき評価した。
（評価基準）
　Ａ：錆が完全に落ちている
　Ｂ：錆がほぼ完全に落ちている
　Ｃ：錆がやや残っている
　Ｄ：錆が残っている [Evaluation of rust removal properties]
Under the test conditions of initial braking speed of 60 km / h, 2.0 MPa braking, 1000 times of braking, and brake temperature before braking of 100 ° C., the degree of rust grinding of the disk rotor that had previously generated rust on the surface was evaluated based on the following criteria: .
(Evaluation criteria)
A: Rust has fallen completely B: Rust has fallen almost completely C: Rust remains a little D: Rust remains
Figure JPOXMLDOC01-appb-T000001
Figure JPOXMLDOC01-appb-T000001
　実施例１～４は、銅を含有する比較例１と同水準の低速低温制動時の摩擦係数安定性を示すと共に、比較例１に対して通常制動時の摩擦係数及び錆取り性が良好である。また、実施例１～４は、ショット含有量が０．２質量％未満である鉱物繊維Ａを使用した比較例２に対して、一制動中の摩擦係数変動率、通常制動域における摩擦係数及び錆取り性に優れており、低速低温制動域における優れた摩擦係数の安定性と、通常制動域における優れた摩擦係数とを両立し、錆取り性に優れていることが分かる。 Examples 1 to 4 show the friction coefficient stability during low-speed and low-temperature braking at the same level as Comparative Example 1 containing copper, and the friction coefficient and rust removing property during normal braking are better than Comparative Example 1. . In addition, Examples 1 to 4 have a friction coefficient variation rate during one braking, a friction coefficient in a normal braking region, and a comparative example 2 using a mineral fiber A having a shot content of less than 0.2% by mass. It is excellent in rust removal property, and it is understood that the stability of the excellent friction coefficient in the low-speed and low-temperature braking region and the excellent friction coefficient in the normal braking region are compatible, and the rust removal property is excellent.
　本発明の摩擦材、摩擦材組成物及び摩擦部材は従来品と比較して、環境負荷の高い銅を用いなくとも、錆取り性に優れるため、一般的な乗用車向けには勿論、回生ブレーキ等の制御ブレーキ搭載の乗用車用ブレーキパッドなどに好適である。
  The friction material, the friction material composition and the friction member of the present invention are excellent in rust removal performance without using copper having a high environmental load as compared with conventional products. It is suitable for a brake pad for a passenger car equipped with a control brake.

Claims (20)

  1. 　銅を含まない、又は含んでいてもその含有量が、銅元素として０．５質量％以下の摩擦材であり、無機繊維（Ｘ１）と該無機繊維（Ｘ１）のショット（Ｘ２）とを含有し、前記ショット（Ｘ２）の含有量が、無機繊維（Ｘ１）及びショット（Ｘ２）の総量中、０．２質量％以上である、摩擦材。 Even if it does not contain copper, the content is a friction material of 0.5 mass% or less as a copper element, and contains inorganic fibers (X1) and shots (X2) of the inorganic fibers (X1) And the friction material whose content of the said shot (X2) is 0.2 mass% or more in the total amount of an inorganic fiber (X1) and a shot (X2).
  2. 　前記無機繊維（Ｘ１）の平均繊維長が、１００～８００μｍである、請求項１に記載の摩擦材。 The friction material according to claim 1, wherein the inorganic fiber (X1) has an average fiber length of 100 to 800 µm.
  3. 　前記無機繊維（Ｘ１）とショット（Ｘ２）の合計含有量が、摩擦材全量１００質量％に対して、１．０質量％以上１０．０質量％未満である、請求項１又は２に記載の摩擦材。 The total content of the inorganic fibers (X1) and shots (X2) is 1.0% by mass or more and less than 10.0% by mass with respect to 100% by mass of the total friction material. Friction material.
  4. 　前記ショット（Ｘ２）の含有量が、無機繊維（Ｘ１）及びショット（Ｘ２）の総量中、０．２～１０質量％である、請求項１～３のいずれか１項に記載の摩擦材。 The friction material according to any one of claims 1 to 3, wherein a content of the shot (X2) is 0.2 to 10% by mass in a total amount of the inorganic fibers (X1) and the shot (X2).
  5. 　前記無機繊維（Ｘ１）及びショット（Ｘ２）中におけるＡｌ２Ｏ３の含有量が、１～３５質量％である、請求項１～４のいずれか１項に記載の摩擦材。 The friction material according to any one of claims 1 to 4, wherein the content of Al 2 O 3 in the inorganic fibers (X1) and shots (X2) is 1 to 35 mass%.
  6. 　さらに、無機充填材として、平均粒子径が０．４～２μｍの珪酸ジルコニウムを、摩擦材全量１００質量％に対して、４～１０質量％含有する、請求項１～５のいずれか１項に記載の摩擦材。 6. The inorganic filler according to claim 1, further comprising 4 to 10% by mass of zirconium silicate having an average particle size of 0.4 to 2 μm with respect to 100% by mass of the total friction material. The friction material described.
  7. 　さらに、無機充填材として、非針状であって平均粒子径が２～５０μｍのチタン酸塩を、摩擦材全量１００質量％に対して、１５～２５質量％含有する、請求項１～６のいずれか１項に記載の摩擦材。 Further, the inorganic filler contains a non-acicular titanate having an average particle diameter of 2 to 50 μm in an amount of 15 to 25% by mass with respect to 100% by mass of the total friction material. The friction material according to any one of claims.
  8. 　さらに、無機充填材として、酸化ジルコニウムを、摩擦材全量１００質量％に対して、１０～２０質量％含有する、請求項１～７のいずれか１項に記載の摩擦材。 The friction material according to any one of claims 1 to 7, further comprising, as an inorganic filler, zirconium oxide in an amount of 10 to 20 mass% with respect to 100 mass% of the total friction material.
  9. 　さらに、無機充填材として、ウォラストナイトを、摩擦材全量１００質量％に対して、２～１０質量％含有する、請求項１～８のいずれか１項に記載の摩擦材。 The friction material according to any one of claims 1 to 8, further comprising 2 to 10% by mass of wollastonite as an inorganic filler with respect to 100% by mass of the total amount of the friction material.
  10. 　請求項１～９のいずれか１項に記載の摩擦材と裏金とを一体化してなる摩擦部材。 A friction member obtained by integrating the friction material according to any one of claims 1 to 9 and a back metal.
  11. 　請求項１０に記載の摩擦部材を搭載した車両。 A vehicle equipped with the friction member according to claim 10.
  12. 　銅を含まない、又は含んでいてもその含有量が、銅元素として０．５質量％以下の摩擦材組成物であり、無機繊維（Ｘ１）と該無機繊維（Ｘ１）のショット（Ｘ２）とを含有し、前記ショット（Ｘ２）の含有量が、無機繊維（Ｘ１）及びショット（Ｘ２）の総量中、０．２質量％以上である、摩擦材組成物。 Even if copper is not included, or the content thereof is a friction material composition of 0.5% by mass or less as a copper element, the inorganic fiber (X1) and the shot (X2) of the inorganic fiber (X1) And the content of the shot (X2) is 0.2% by mass or more in the total amount of the inorganic fibers (X1) and the shot (X2).
  13. 　前記無機繊維（Ｘ１）の平均繊維長が、１００～８００μｍである、請求項１２に記載の摩擦材組成物。 The friction material composition according to claim 12, wherein an average fiber length of the inorganic fibers (X1) is 100 to 800 µm.
  14. 　前記無機繊維（Ｘ１）とショット（Ｘ２）の合計含有量が、摩擦材組成物全量１００質量％に対して、１．０質量％以上１０．０質量％未満である、請求項１２又は１３に記載の摩擦材組成物。 The total content of the inorganic fibers (X1) and shots (X2) is 1.0% by mass or more and less than 10.0% by mass with respect to 100% by mass of the total friction material composition. The friction material composition as described.
  15. 　前記ショット（Ｘ２）の含有量が、無機繊維（Ｘ１）及びショット（Ｘ２）の総量中、０．２～１０質量％である、請求項１２～１４のいずれか１項に記載の摩擦材組成物。 The friction material composition according to any one of claims 12 to 14, wherein a content of the shot (X2) is 0.2 to 10% by mass in a total amount of the inorganic fibers (X1) and the shot (X2). object.
  16. 　前記無機繊維（Ｘ１）及びショット（Ｘ２）中におけるＡｌ２Ｏ３の含有量が、１～３５質量％である、請求項１２～１５のいずれか１項に記載の摩擦材組成物。 The friction material composition according to any one of claims 12 to 15, wherein the content of Al 2 O 3 in the inorganic fibers (X1) and shots (X2) is 1 to 35 mass%.
  17. 　さらに、無機充填材として、平均粒子径が０．４～２μｍの珪酸ジルコニウムを、摩擦材組成物全量１００質量％に対して、４～１０質量％含有する、請求項１２～１６のいずれか１項に記載の摩擦材組成物。 Furthermore, as an inorganic filler, zirconium silicate having an average particle size of 0.4 to 2 μm is contained in an amount of 4 to 10% by mass with respect to 100% by mass of the total amount of the friction material composition. The friction material composition according to item.
  18. 　さらに、無機充填材として、非針状であって平均粒子径が２～５０μｍのチタン酸塩を、摩擦材組成物全量１００質量％に対して、１５～２５質量％含有する、請求項１２～１７のいずれか１項に記載の摩擦材組成物。 Furthermore, the inorganic filler contains 15 to 25% by mass of non-acicular titanate having an average particle diameter of 2 to 50 μm with respect to 100% by mass of the total amount of the friction material composition. The friction material composition according to any one of 17.
  19. 　さらに、無機充填材として、酸化ジルコニウムを、摩擦材組成物全量１００質量％に対して、１０～２０質量％含有する、請求項１２～１８のいずれか１項に記載の摩擦材組成物。 The friction material composition according to any one of claims 12 to 18, further comprising zirconium oxide as an inorganic filler in an amount of 10 to 20% by mass with respect to 100% by mass of the total amount of the friction material composition.
  20. 　さらに、無機充填材として、ウォラストナイトを、摩擦材組成物全量１００質量％に対して、２～１０質量％含有する、請求項１２～１９のいずれか１項に記載の摩擦材組成物。
          The friction material composition according to any one of claims 12 to 19, further comprising 2 to 10% by mass of wollastonite as an inorganic filler with respect to 100% by mass of the total amount of the friction material composition.
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Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2022209400A1 (en) * 2021-03-29 2022-10-06 曙ブレーキ工業株式会社 Friction material
CN115698217A (en) * 2020-06-02 2023-02-03 住友电木株式会社 Phenolic resin composition for friction material

Citations (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2001072961A (en) * 1999-09-07 2001-03-21 Toshiba Monofrax Co Ltd Friction material
WO2007080975A1 (en) * 2006-01-13 2007-07-19 Hitachi Chemical Co., Ltd. Composition for friction material and friction material using same
WO2012066969A1 (en) * 2010-11-19 2012-05-24 日立化成工業株式会社 Non-asbestos friction material composition, and friction material and friction member using same
WO2014034878A1 (en) * 2012-08-30 2014-03-06 日立化成株式会社 Friction material composition, friction material using friction material composition, and friction member
JP2015059142A (en) * 2013-09-17 2015-03-30 曙ブレーキ工業株式会社 Friction material
JP2017095646A (en) * 2015-11-27 2017-06-01 曙ブレーキ工業株式会社 Friction material
JP2017149971A (en) * 2011-09-14 2017-08-31 曙ブレーキ工業株式会社 Friction material

Family Cites Families (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2587740B2 (en) * 1991-10-11 1997-03-05 ニチアス株式会社 Disc roll and manufacturing method thereof
JP5970749B2 (en) * 2011-06-07 2016-08-17 日立化成株式会社 Non-asbestos friction material composition
JP5174948B1 (en) * 2011-12-23 2013-04-03 ニチアス株式会社 Biologically soluble inorganic fiber and method for producing the same

Patent Citations (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2001072961A (en) * 1999-09-07 2001-03-21 Toshiba Monofrax Co Ltd Friction material
WO2007080975A1 (en) * 2006-01-13 2007-07-19 Hitachi Chemical Co., Ltd. Composition for friction material and friction material using same
WO2012066969A1 (en) * 2010-11-19 2012-05-24 日立化成工業株式会社 Non-asbestos friction material composition, and friction material and friction member using same
JP2017149971A (en) * 2011-09-14 2017-08-31 曙ブレーキ工業株式会社 Friction material
WO2014034878A1 (en) * 2012-08-30 2014-03-06 日立化成株式会社 Friction material composition, friction material using friction material composition, and friction member
JP2015059142A (en) * 2013-09-17 2015-03-30 曙ブレーキ工業株式会社 Friction material
JP2017095646A (en) * 2015-11-27 2017-06-01 曙ブレーキ工業株式会社 Friction material

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN115698217A (en) * 2020-06-02 2023-02-03 住友电木株式会社 Phenolic resin composition for friction material
WO2022209400A1 (en) * 2021-03-29 2022-10-06 曙ブレーキ工業株式会社 Friction material

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