WO2020021646A1 - Friction member, friction material composition for lower layer materials, lower layer material, disc brake pad and automobile - Google Patents

Friction member, friction material composition for lower layer materials, lower layer material, disc brake pad and automobile Download PDF

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Publication number
WO2020021646A1
WO2020021646A1 PCT/JP2018/027778 JP2018027778W WO2020021646A1 WO 2020021646 A1 WO2020021646 A1 WO 2020021646A1 JP 2018027778 W JP2018027778 W JP 2018027778W WO 2020021646 A1 WO2020021646 A1 WO 2020021646A1
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WIPO (PCT)
Prior art keywords
particles
friction
fiber
back plate
friction member
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PCT/JP2018/027778
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French (fr)
Japanese (ja)
Inventor
良尚 高橋
光朗 海野
一 豊田
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日立化成株式会社
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Priority to JP2020531886A priority Critical patent/JPWO2020021646A1/en
Priority to PCT/JP2018/027778 priority patent/WO2020021646A1/en
Publication of WO2020021646A1 publication Critical patent/WO2020021646A1/en

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    • 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
    • F16D69/025—Compositions based on an organic binder
    • F16D69/026—Compositions based on an organic binder containing fibres
    • 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
    • F16D65/00—Parts or details
    • F16D65/02—Braking members; Mounting thereof
    • F16D65/04—Bands, shoes or pads; Pivots or supporting members therefor
    • F16D65/092—Bands, shoes or pads; Pivots or supporting members therefor for axially-engaging brakes, e.g. disc brakes
    • 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
    • F16D2200/00—Materials; Production methods therefor
    • F16D2200/0004—Materials; Production methods therefor metallic
    • F16D2200/0026—Non-ferro
    • F16D2200/003—Light metals, e.g. aluminium
    • 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
    • F16D2200/00—Materials; Production methods therefor
    • F16D2200/006—Materials; Production methods therefor containing fibres or particles

Definitions

  • the present invention relates to a friction member, a friction material composition for an underlining material, an underlining material, a disc brake pad, and a vehicle.
  • FIGS. 1 and 2 show an example of a disc brake pad as a friction member for braking attached to a motorcycle or a four-wheeled vehicle.
  • FIG. 1 is a top view of the disc brake pad
  • FIG. 2 is an example of a cross-sectional view taken along line AA of FIG.
  • the disc brake pad is composed of a back plate 1 and a friction material 2, and the friction material 2 is directly fixed to one surface 11 of the back plate 1 (here, the upper surface of the back plate 1).
  • the friction material 2 is made of, for example, a so-called resin mold material including a binder, an organic filler, an inorganic filler, and a fiber base material.
  • a preform of a friction material composed of a binder, an organic filler, an inorganic filler, and a fiber base material is preliminarily superimposed on one surface of the back plate 1 and then hot-pressed to form an integrated body. It is manufactured by applying a surface treatment after being fixed to the surface.
  • FIG. 3 shows another example of the disc brake pad.
  • FIG. 3 is another example of a cross-sectional view taken along line AA of FIG.
  • the disc brake pad of FIG. 3 includes a back plate 1, a friction material (also referred to as an upper material in FIG. 3) 2 and a lower material 3, and one surface 11 of the back plate 1 (here, the back plate 1).
  • a friction material (upper material) 2 is fixed to a lower surface material 3 via a lower material 3.
  • the disc brake pad is preliminarily laminated on one surface of the back plate 1 with a preformed body of a friction material and an underlay material composed of a binder, an organic filler, an inorganic filler and a fiber base material, and then hot-pressed. It is manufactured by performing surface processing after being fixed integrally.
  • the specific gravity of steel sheet is about 7.8 mg / m 3
  • the specific gravity of aluminum is about 2.7 Mg / m 3 as compared to
  • lighter specific gravity of the resin is from about 1 Mg / m 3, such as aluminum and resin
  • the present inventors have been studying to change the back plate from a conventional steel-made one to a light-weight material such as resin or aluminum in order to reduce the weight of the disc brake pad. It has been found that the lightweight material has insufficient durability after repeated braking compared to the conventional steel back plate.
  • a friction member such as a disc brake pad
  • the present inventors have conducted intensive studies to solve the above-mentioned problems, and as a result, by including specific particles in the underlining material, the durability of the back plate after repeated braking is improved even when the back plate is reduced in weight. As a result, it has been found that the durability of the friction member after repeated braking can be improved, and the present invention has been completed. The present invention has been completed based on such findings.
  • the present invention relates to the following [1] to [16].
  • [1] A friction member in which a friction material (upper material) is disposed on one surface of a back plate containing a material having a specific gravity lower than that of steel via a lower material, wherein the lower material has particles having voids. Friction member to contain.
  • [2] The friction member according to [1], wherein the porosity of the particles having voids is 30% by volume or more.
  • the particles having voids are selected from the group consisting of fly ash balloons, shirasu balloons, diatomaceous earth, hollow glass particles, calcium silicate particles, hollow silica particles, alumina balloons, zirconia balloons, ⁇ -alumina particles, and phenol resin balloons.
  • the back plate is made of (1) a fiber-reinforced resin, (2-1) an aluminum alloy, (2-2) an aluminum composite material in which ceramic particles are dispersed in aluminum or an aluminum alloy, and (3-1) a magnesium alloy.
  • Friction member a magnesium composite material in which ceramic particles are dispersed in magnesium or a magnesium alloy, and at least one selected from the group consisting of: Friction member.
  • Friction member The friction member according to the above [6], wherein the back plate contains the (1) fiber-reinforced resin or the (2-1) aluminum alloy.
  • a disc brake pad including the friction member according to any one of [1] to [7].
  • a friction material composition for a subbing material comprising particles having voids.
  • the particles having voids are selected from the group consisting of fly ash balloons, shirasu balloons, diatomaceous earth, hollow glass particles, calcium silicate particles, hollow silica particles, alumina balloons, zirconia balloons, ⁇ -alumina particles, and phenol resin balloons.
  • the friction for underlining materials according to any of [10] to [12] further comprising at least one selected from the group consisting of an organic filler, an inorganic filler, a fiber base material, and a binder. Material composition.
  • the present invention it is possible to reduce the weight of the friction member (such as a disc brake pad) by reducing the weight of the back plate, and to provide a friction member having improved durability after repeated braking. Further, since the specific gravity of the back plate is smaller than steel, the weight of friction members such as disc brake pads is reduced, thereby contributing to the weight reduction of vehicle bodies such as motorcycles and four-wheeled vehicles.
  • the friction member such as a disc brake pad
  • FIG. 2 is a schematic view of a friction member (disk brake pad) in which a friction material is directly arranged on one surface of a back plate, taken along a line AA in FIG. 1.
  • FIG. 2 is a schematic cross-sectional view of the friction member (disc brake pad) in which a friction material (upper material) is disposed on one surface of a back plate via a lower material, taken along the line AA in FIG. 1.
  • the components are not essential unless otherwise specified.
  • the upper limit or the lower limit of the numerical range may be replaced with the value shown in the embodiment.
  • the content of each component in the underlining material or the friction material composition for the underlining material when there are a plurality of types of substances corresponding to each component, unless otherwise specified, It means the total content of the plurality of types of substances present in the material friction material composition.
  • embodiments in which the items described in this specification are arbitrarily combined are also included in the present invention.
  • the brake temperature rises due to frictional heat, and the surface temperature of the friction material may be about 600 ° C. or more. It was found that the temperature of the back plate may rise to 250 ° C. or more when the amount of decreased.
  • the resin is thermally decomposed, the strength of the back plate is significantly reduced, and cracks and It has been found that defects such as cracks are likely to occur.
  • FIG. 1 A friction member in which a friction material (upper material) 2 is disposed on one surface of a back plate 1 containing a material having a specific gravity lower than that of steel with an under material 3 interposed therebetween, wherein the under material 3 is a particle having voids.
  • the back plate 1 will be described in detail.
  • the back plate contains a material having a lower specific gravity than steel.
  • the back plate contains a material having a specific gravity lower than that of steel, preferably 50% by volume or more, more preferably 80% by volume or more, and still more preferably 90% by volume or more, and is made of a material having a specific gravity lower than steel. Is particularly preferred.
  • the material having a specific gravity lower than that of steel is preferably a material having a specific gravity of 5 Mg / m 3 or less, more preferably a material having a specific gravity of 3 Mg / m 3 or less, and still more preferably a material having a specific gravity of 2 Mg / m 3 or less.
  • the specific gravity of the back plate is 5 mg / m 3 or less, more preferably 3Mg / m 3 or less, and more preferably 2Mg / m 3 or less.
  • the material having a lower specific gravity than steel examples include (1) fiber-reinforced resin, (2-1) aluminum alloy, (2-2) aluminum or an aluminum composite material in which ceramic particles are dispersed in aluminum or an aluminum alloy, (3-1) And (3-2) magnesium or a magnesium composite material in which ceramic particles are dispersed in a magnesium alloy.
  • the back plate contains at least one selected from the group consisting of the materials (1), (2-1), (2-2), (3-1) and (3-2). And at least one selected from the group consisting of the above-mentioned materials (1), (2-1), (2-2), (3-1) and (3-2), Is also good.
  • materials having a lower specific gravity than steel are preferably (1) fiber reinforced resin and (2-1) aluminum alloy, (1) fiber reinforced resin or (2-1) aluminum alloy. There may be.
  • the fiber-reinforced resin refers to a composite of fiber and resin, that is, a composite of fiber and resin. Since the specific gravity of the fiber reinforced resin is about 1 Mg / m 3, it is suitable as a lightweight material.
  • the fiber used for the fiber-reinforced resin examples include glass fiber, alumina fiber such as ⁇ -alumina type and ⁇ -alumina type, and inorganic fiber such as boron fiber; aramid fiber such as para-aramid fiber and meta-aramid fiber; At least one selected from the group consisting of cellulose fibers, nanocellulose fibers, PBO (polyparaphenylenebenzoxazole) fibers, or oxidized fibers, pitch-based fibers, and carbon-based fibers such as PAN (polyacrylonitrile) -based carbon fibers; Can be used. Particularly when used as a back plate, glass fibers and carbon fibers are preferred from the viewpoint of strength and rigidity, and carbon fibers are more preferred from the viewpoint of high thermal conductivity.
  • the thermal conductivity of the back plate can be further improved, and when the braking temperature is increased by frictional heat due to repeated braking, the temperature distribution in the back plate can be made uniform. In addition, there is a tendency that a local temperature rise is prevented, and cracks and cracks due to thermal decomposition and a decrease in strength of the resin are easily prevented.
  • the fiber length of the fiber used in the fiber reinforced resin is not particularly limited, but from the viewpoint of strength, a fiber length of 1 mm or more is preferable, and a long fiber of 10 mm or more is more preferable.
  • the upper limit of the fiber length of the fiber is not particularly limited, and may be 100 mm or less, 70 mm or less, 50 mm or less, or 35 mm or less.
  • a nonwoven fabric such as a felt, a paper product, a woven fabric composed of continuous fibers, a knitted fabric, and a woven fabric such as a mixed fabric can also be used.
  • a thermosetting resin is preferable from the viewpoint of heat resistance
  • a phenol resin, an epoxy resin, and a polyimide resin are preferable from the viewpoint of heat resistance and strength.
  • the phenol resin and the epoxy resin any of a novolak type and a resol type can be used.
  • the epoxy resin or the phenol is a novolak type, it is preferable to use a curing agent in combination.
  • the resin used for the fiber reinforced resin one type may be used alone, or two or more types may be used in combination.
  • the phenol resin a commercially available product can be used, and the phenol resin can be synthesized by a conventional method.
  • the phenol resin examples include a resol-type phenol resin, a straight novolak-type phenol resin, an aralkyl-modified phenol resin, an elastomer-modified phenol resin modified with an acrylic elastomer, a silicone elastomer, and the like. From the viewpoint of heat resistance, a straight novolak type phenol resin or a resol type phenol resin is preferable as the phenol resin.
  • the epoxy resin a commercially available product can be used, and the epoxy resin can be synthesized by an ordinary method.
  • the epoxy resin is preferably an epoxy resin having an aromatic ring from the viewpoint of strength and heat resistance.
  • a phenol novolak type epoxy resin, a cresol novolak type epoxy resin, a naphthalene type epoxy resin, or the like can be suitably used.
  • epoxy resin modified with silicone, acrylonitrile, butadiene, isopropyl rubber, polyamide resin, or the like can also be used.
  • additives can be blended in addition to the fibers and the resin.
  • Other additives include inorganic fillers, organic fillers, metal powders and the like.
  • the other additives one kind may be used alone, and two kinds or more may be used in combination. It is preferably a particulate inorganic filler, organic filler, or metal powder.
  • the particle diameter is preferably small.
  • graphite, molybdenum disulfide, tungsten sulfide, fluororesin, coke, and the like are mentioned.
  • magnesium hydroxide and aluminum hydroxide are used.
  • antimony compounds, etc. from the viewpoint of weight reduction, hollow inorganic particles, etc., from the viewpoint of improving the curing speed of the resin, calcium oxide, calcium hydroxide, etc., to improve the thermal conductivity From the point of view, metal powder, graphite, magnesium oxide, zinc oxide and the like can be mentioned.
  • the fiber reinforced resin preferably has a thermal conductivity in the thickness direction of 0.30 W / m ⁇ K or more, and 0.35 W / m ⁇ K or more, in order to prevent a local temperature rise of the back plate. Is more preferable, and more preferably 0.40 W / mK or more.
  • the thermal conductivity in the thickness direction of the fiber reinforced resin As a method for setting the thermal conductivity in the thickness direction of the fiber reinforced resin to the above range, a method of adding an additive having a high thermal conductivity such as the metal powder, graphite, magnesium oxide, and zinc oxide to the fiber reinforced resin, As a fiber of the reinforced resin, a method using a fiber having a high thermal conductivity such as a carbon fiber may be used, and a fiber reinforced resin employing one of these methods alone or a combination of two or more thereof may be used.
  • the thickness direction is the direction from the surface of the friction material slidingly contacting the mating material to the back plate
  • the thermal conductivity is the thermal conductivity measured at room temperature (25 ° C.) by a temperature gradient method. It is.
  • the temperature gradient method is a method of measuring the thermal conductivity of a sample from the heat flux and the sample temperature when the sample in contact with two objects having a temperature difference reaches a steady state.
  • the thermal conductivity measured by the method can be measured using a commercially available measuring device.
  • the thermal conductivity measured by the temperature gradient method is the thermal conductivity measured by the method described in the examples.
  • the fiber reinforced resin is molded and, if necessary, shaped to produce a fiber reinforced resin back plate.
  • the above friction member can be manufactured by using it instead of the back plate made of. That is, the preformed friction material composition is inserted into the mold hole of the thermoforming mold of the friction material as necessary, and then is adhered to the back plate made of the fiber reinforced resin in contact with the preformed body. The thing which applied the agent is arranged. Then, the friction material composition is thermoformed to form a friction material (upper material) and a lower material, whereby the fiber reinforced resin and the friction material are integrated via the lower material to form a friction member. it can.
  • thermoforming of the back plate made of the fiber reinforced resin and the thermoforming of the friction material (upper material) and the lower material are performed separately, so that the energy efficiency is not necessarily good. Therefore, energy efficiency can be improved by simultaneously performing thermoforming of the back plate made of the fiber reinforced resin and thermoforming of the friction material (upper material) and the lower material. That is, the fiber reinforced resin in a state before the thermosetting and the friction material composition which has been preformed as necessary are inserted, and simultaneously thermoformed, and the thermosetting in the fiber reinforced resin in the thermoforming step is performed. By melting and hardening the thermosetting resin and the thermosetting resin in the friction material, they can be integrated without the need for an adhesive.
  • Aluminum has a small specific gravity of about 2.7 Mg / m 3 and is suitable as a lightweight material. However, from the viewpoint of strength, it is preferable to use an aluminum alloy as the back plate.
  • Aluminum alloys include 2XXX (Al-Cu), 3XXX (Al-Mn), 4XXX (Al-Si), 5XXX (Al-Mg), and 6XXX (Al-Mg-Si).
  • AC1C Al-Cu-based
  • AC1B Al-Cu-based
  • AC2A Al-Cu-Si-based
  • AC2B Al-Cu-) Si-based
  • AC3A Al-Si-based
  • AC4A AC4C
  • AC4C Al-Si-Mg-based
  • AC4B Al-Si-Cu-based
  • AC4D Al-Si-Cu-Mg-based
  • AC5A Al- Cu-Ni-Mg
  • AC7A Al-Mg
  • AC8A Al-Si-Cu-Ni-Mg
  • AC8B Al-Si-Cu-Ni-Mg
  • AC9A Al-Si-) Cu-Mg type , AC9B (Al-Si-Cu-Mg) and other casting aluminum alloys
  • ADC1 Al-Si
  • ADC3 Al-Si
  • Aluminum composite materials (ceramic particle reinforced aluminum-based composite materials) in which ceramic particles are dispersed in aluminum or the above aluminum alloy have a higher Young's modulus than aluminum alloys. The rigidity can be increased, which is preferable.
  • oxide ceramics such as Al 2 O 3 , TiO 2 , SiO 2 , ZrO 2 , carbide ceramics such as SiC and TiC, and nitride ceramics such as TiN can be used.
  • magnesium alloy Since magnesium has a small specific gravity of 1.74 Mg / m 3 , it is suitable as a lightweight material, but from the viewpoint of strength, it is preferable to use a magnesium alloy as the back plate.
  • magnesium alloys include M1 (Mg-Mn alloy), AZ-based (Mg-Al-Zn alloy) such as AZ61 and AZ91, ZK-based (Mg-Zn-Zr alloy) such as ZK51 and ZK60, and ZH-based such as ZH62.
  • magnesium alloys for casting such as EK-based (Mg-rare earth element alloy) such as EK30, HK-based (Mg-Th-based alloy) such as HK31, and K1 (Mg-Zr alloy);
  • EK-based Mg-rare earth element alloy
  • HK-based Mg-Th-based alloy
  • K1 Mg-Zr alloy
  • a magnesium alloy for processing can be used.
  • a flame-retardant magnesium alloy to which calcium is added by several% can be used.
  • Ceramic particle reinforced magnesium-based composite material in which ceramic particles are dispersed in magnesium or the above magnesium alloy has a higher Young's modulus than a magnesium alloy.
  • the rigidity can be increased, which is preferable.
  • oxide ceramics such as Al 2 O 3 , TiO 2 , SiO 2 , ZrO 2 , carbide ceramics such as SiC and TiC, and nitride ceramics such as TiN can be used.
  • the thermal conductivity in the thickness direction of the back plate is preferably 0.30 W / m ⁇ K or more, more preferably 0.35 W / m ⁇ K or more, and 1.0 W / m ⁇ K or more. More preferably, it is K or more.
  • the upper limit of the thermal conductivity in the thickness direction of the back plate is not particularly limited, but may be 400 W / m ⁇ K or less, 250 W / m ⁇ K or less, or 150 W / m ⁇ K. It may be as follows.
  • the present invention also provides an underlining material formed by molding the underlining material friction material composition, and each component that can be contained in the “underlining material friction material composition” is included in the “underlining material”. It is a component to be obtained.
  • the description about each component in the “friction material composition for underlining material” described below can be read as the description about each component in the “underlining material”.
  • the friction material composition for underlining material used in the present invention is a friction material composition for underlining material containing particles having voids.
  • a preferred embodiment of the friction material composition for an underlining material used in the present invention is, together with the particles having voids, at least one selected from the group consisting of an organic filler, an inorganic filler, an organic fiber, and a binder (however, The particles having the voids are excluded from the organic filler and the inorganic filler.)
  • a more preferred embodiment is a friction material composition for an underlaying material, which further comprises an organic filler together with the particles having the voids.
  • a friction material composition for an underlining material comprising a material, an inorganic filler, an organic fiber, and a binder (however, the particles having the voids are excluded from the organic filler and the inorganic filler).
  • a friction material containing copper or a copper alloy is advantageous for the strength of the friction material.
  • a friction material containing copper or a copper alloy contains copper as wear powder generated by braking. It has been suggested that it causes pollution of rivers, lakes and oceans due to its large amount, and the use of copper components in friction materials (overlaying materials) has been reduced mainly in the United States, especially California and Washington. Restricting laws are in place. Therefore, in order to be a friction material that can be used in other countries including the United States, it is necessary to not contain copper or to significantly reduce the content of copper. Commercial value is poor.
  • the friction material composition for underlining material of the present invention does not contain copper, but when copper is contained, the content of copper in the friction material composition for underlining material is 0.5 mass% as a copper element. By setting it to less than%, even if it is released as abrasion powder into the environment, it is possible to prevent pollution of rivers and the like.
  • the copper content indicates the content of copper element (Cu) contained in fibrous and powdery copper, copper alloys and copper compounds in the entire friction material composition for underlining materials.
  • the content of copper in the friction material composition for underlaying material is more preferably 0.2% by mass or less as a copper element, and further preferably 0.05% by mass or less. As described above, in the friction material composition for underlining material of the present invention, it is preferable that copper is not contained, or even if copper is contained, its content is less than 0.5% by mass as a copper element.
  • the iron-based metal is a metal containing iron as a main component and refers to general iron and steel. The iron content is determined based on the iron element (Fe) contained in iron, iron alloys, and iron compounds.
  • the friction material composition for an underlining material of the present invention does not contain an iron-based metal.
  • the content of the iron-based metal in the friction material composition for iron less than 0.5% by mass as an iron element, rust resistance can be improved, and rusting occurs at the bonding interface with the back plate. Can suppress the reduction in durability.
  • the content of the iron-based metal is suppressed to the above range, it has sufficient toughness, high shear strength at room temperature or high temperature, good crack resistance, and good wear resistance. is there.
  • the content of the iron-based metal in the friction material composition for underlaying material is more preferably 0.2% by mass or less as an iron element, and further preferably 0.05% by mass or less. As described above, in the friction material composition for underlining material of the present invention, it is preferable that the iron-based metal is not contained or the content thereof is less than 0.5% by mass as an iron element.
  • the friction material composition for underlining material of the present invention is classified as a non-asbestos-organic (NAO) material, and is a so-called non-asbestos friction material composition (a friction material composition containing no asbestos or containing asbestos). Even when the friction material composition is used, the asbestos content is a very small amount.
  • the content of asbestos is preferably 0.2% by mass or less, more preferably substantially 0% by mass.
  • the friction material composition for underlining material of the present invention contains voided particles.
  • the particles having voids one type may be used alone, or two or more types may be used in combination.
  • the durability of the back plate after repeated braking is improved.
  • it is possible to form a gap in the underlaying material by means such as generating a crack in the underlaying material the strength of the underlining material is reduced in this method, so that together with the strength, the durability of the back plate after repeated braking is reduced.
  • the particles having voids are selected from the group consisting of, for example, fly ash balloons, shirasu balloons, diatomaceous earth, hollow glass particles, calcium silicate particles, hollow silica particles, alumina balloons, zirconia balloons, ⁇ -alumina particles, and phenol resin balloons. Preferably, at least one of them is used.
  • the particles having voids may have voids in the primary particles, or even if they do not have voids in the primary particles, voids may be formed in the secondary particles formed by aggregation of the primary particles. You may have.
  • the secondary particles refer to, for example, particles in which several to several tens of primary particles are in contact with each other to form pseudo particles.
  • those having voids in the primary particles include, for example, hollow glass particles, hollow silica particles, fly ash balloons, shirasu balloons, alumina balloons, zirconia balloons, phenol resin balloons, and the like.
  • hollow glass particles and calcium silicate particles are preferable, and hollow glass particles are more preferable from the viewpoint of the strength of the underlay material and the durability of the back plate after repeated braking.
  • the primary average particle size is not particularly limited, but is preferably 5 to 400 ⁇ m, more preferably 10 to 300 ⁇ m, further preferably 10 to 150 ⁇ m, particularly preferably 10 to 100 ⁇ m, and most preferably 15 to 60 ⁇ m. is there.
  • the particles having voids those having voids in the secondary particles include, for example, calcium silicate particles, ⁇ -alumina particles, and diatomaceous earth. Among these, calcium silicate particles and ⁇ -alumina particles are preferred.
  • the secondary average particle size is not particularly limited, but is preferably 5 to 400 ⁇ m, more preferably 10 to 300 ⁇ m, and further preferably 30 to 250 ⁇ m.
  • the secondary average particle size may be from 10 to 150 ⁇ m or from 30 to 100 ⁇ m. In the case of ⁇ -alumina particles, the secondary average particle diameter may be 100 to 400 ⁇ m, 150 to 300 ⁇ m, or 150 to 250 ⁇ m.
  • the particles having voids are preferably at least one selected from the group consisting of hollow glass particles, calcium silicate particles, and ⁇ -alumina particles. At least one selected from the group consisting of particles and calcium silicate particles is more preferable, and hollow glass particles are more preferable. Examples of the hollow glass particles include hollow silicate glass particles, hollow aluminum silicate glass particles, and hollow borosilicate glass particles.
  • the porosity of the particles having voids is not particularly limited, but from the viewpoint of the durability of the back plate after repeated braking, is preferably 30% by volume or more, more preferably 50% by volume or more, and still more preferably 65% by volume or more. It is particularly preferably at least 70% by volume.
  • the content of particles having voids is preferably 0.1 to 30% by mass, more preferably 0.5 to 25% by mass, still more preferably 1 to 15% by mass, and particularly preferably. Is 1 to 8% by mass.
  • the organic filler can exhibit a function as a friction modifier for improving the vibration damping property and the wear resistance.
  • the organic filler does not include a fibrous material (for example, an organic fiber described later).
  • One kind of the organic filler may be used alone, or two or more kinds may be used in combination.
  • an organic filler generally used in a friction material composition can be used, and examples thereof include cashew particles, rubber, and melamine dust. Among these, cashew particles and rubber are preferable from the viewpoint of improving the stability of the coefficient of friction and the abrasion resistance and suppressing the squeal. Further, as the organic filler, cashew particles and rubber may be used in combination, or cashew particles coated with rubber may be used.
  • the cashew particles are obtained by pulverizing hardened cashew nut shell oil and may be generally referred to as cashew dust.
  • Cashew particles are generally classified into brown, brown-black, black, and the like, depending on the type of curing agent used in the curing reaction.
  • the average particle size of the cashew particles is preferably 850 ⁇ m or less, more preferably 750 ⁇ m or less, and even more preferably 600 ⁇ m or less, from the viewpoint of dispersibility.
  • the lower limit of the average particle size of the cashew particles is not particularly limited, and may be 200 ⁇ m or more, 300 ⁇ m or more, or 400 ⁇ m or more.
  • the average particle diameter means a value of d50 (median diameter of volume distribution, cumulative median value) measured using a laser diffraction particle size distribution measuring method, and the same applies hereinafter. For example, it can be measured with a laser diffraction / scattering type particle size distribution analyzer, trade name: LA.920 (manufactured by Horiba, Ltd.).
  • One type of cashew particles may be used alone, or two or more types may be used in combination.
  • the content is preferably 0.5 to 15% by mass, more preferably 1 to 10% by mass, and still more preferably 2 to 5% by mass. It is.
  • the content is 0.5% by mass or more, the water repellency of the friction material and the disk rotor surface tends to be improved, and the friction material can be given appropriate flexibility, so that sound vibration can be improved. There is a tendency.
  • the content is set to 15% by mass or less, a decrease in heat resistance and crack resistance tends to be prevented.
  • Examples of the rubber include rubbers commonly used in friction material compositions, such as natural rubber and synthetic rubber.
  • Examples of the synthetic rubber include acrylonitrile-butadiene rubber (NBR), acrylic rubber, isoprene rubber, and polybutadiene rubber. (BR), styrene-butadiene rubber (SBR), silicone rubber, pulverized powder of tire tread rubber, and the like.
  • NBR acrylonitrile-butadiene rubber
  • NBR acrylonitrile-butadiene rubber
  • SBR styrene-butadiene rubber
  • silicone rubber pulverized powder of tire tread rubber
  • acrylonitrile-butadiene rubber (NBR) and pulverized powder of tire tread rubber are preferable from the viewpoint of balance between heat resistance, flexibility and production cost.
  • the friction material composition for underlining material of the present invention contains rubber
  • its content is preferably 1 to 30% by mass, more preferably 2 to 15% by mass, and still more preferably, in the friction material composition for underlining material. Is from 2 to 6% by mass.
  • the friction material composition for underlining material contains an organic filler
  • its content is preferably 1 to 20% by mass, more preferably 2 to 10% by mass, and still more preferably, in the friction material composition for underlining material. It is 3 to 10% by mass.
  • the inorganic filler can exhibit a function as a friction adjusting material for avoiding deterioration of the heat resistance, abrasion resistance, stability of friction coefficient and the like of the underlining material.
  • the inorganic filler does not include a fibrous material (for example, an inorganic fiber described later).
  • a fibrous material for example, an inorganic fiber described later.
  • the inorganic filler one type may be used alone, or two or more types may be used in combination.
  • the inorganic filler is not particularly limited, and may be an inorganic filler usually used for an underlay material.
  • the inorganic filler examples include metal sulfides such as antimony trisulfide, tin sulfide, molybdenum disulfide, bismuth sulfide, and zinc sulfide; and titanium such as potassium titanate, lithium potassium titanate, sodium titanate, and potassium magnesium titanate.
  • metal sulfides such as antimony trisulfide, tin sulfide, molybdenum disulfide, bismuth sulfide, and zinc sulfide
  • titanium such as potassium titanate, lithium potassium titanate, sodium titanate, and potassium magnesium titanate.
  • Acid salts mica, graphite, coke, calcium hydroxide, calcium oxide, sodium carbonate, calcium carbonate, magnesium carbonate, barium sulfate, dolomite, coke, mica, vermiculite, calcium sulfate, granular potassium titanate, plate-like potassium titanate, Talc, clay, zeolite, chromite, zirconium oxide, titanium oxide, magnesium oxide, triiron tetroxide, zinc oxide, ⁇ -alumina; iron powder, cast iron powder, aluminum powder, nickel powder, tin powder, zinc powder, and the above metals Small of A metal powder of an alloy powder and the like containing Kutomo one metals, but preferably containing no copper and ferrous metal.
  • at least one selected from the group consisting of metal sulfides, titanates, mica, graphite, calcium hydroxide, and barium sulfate may be used, and barium sulfate is preferred.
  • the graphite is not particularly limited, and any known graphite, that is, natural graphite or artificial graphite can be used.However, in order to suppress an increase in the thermal conductivity of the underlining material, The content is preferably 5% by mass or less, more preferably 3% by mass or less, further preferably 2% by mass or less, and particularly preferably substantially 0% by mass, in the friction material composition for underlining material.
  • the friction material composition for underlining material of the present invention contains barium sulfate, the content thereof is not particularly limited, and the total amount of the friction material composition for underlining material is 100 in accordance with the blending amount of other components. It corresponds to the "remainder" for adjusting to parts by mass.
  • the content is preferably 20 to 75% by mass, more preferably 30 to 70% by mass in the friction material composition for underlining material. More preferably, it is 40 to 65% by mass, particularly preferably 40 to 60% by mass.
  • the upper limit of the content of the inorganic filler may be 55% by mass or less.
  • the fibrous base material has a reinforcing effect on the underlay material.
  • the friction material composition for underlining material of the present invention preferably contains an organic fiber and an inorganic fiber as a fiber base material.
  • One type of fiber base material may be used alone, or two or more types may be used in combination.
  • Inorganic fibers can exhibit the effect of improving the mechanical strength and wear resistance of the underlay material.
  • the organic fiber is a fibrous material containing an organic substance as a main component.
  • the organic fiber examples include hemp, cotton, aramid fiber, cellulose fiber, acrylic fiber, and phenol resin fiber (having a crosslinked structure).
  • One type of organic fiber may be used alone, or two or more types may be used in combination.
  • an aramid fiber is preferable from the viewpoint of heat resistance.
  • the organic fibers contain fibrillated organic fibers, and it is more preferable that they contain fibrillated aramid fibers.
  • the fibrillated organic fiber is an organic fiber that has been split and has fluff, and is commercially available.
  • the friction material composition for underlining material of the present invention may contain other organic fibers together with the fibrillated organic fibers.
  • the content is preferably 1 to 8% by mass in the friction material composition for underlining material.
  • the content is more preferably 2 to 7% by mass, and still more preferably 3 to 7% by mass.
  • the organic fibers (fibrillated organic) in the friction material composition for underlining material are used. Deterioration of shear strength and crack resistance due to uneven distribution of fibers and other materials can be effectively suppressed.
  • the inorganic fiber examples include glass fiber, fibrous wollastonite, metal fiber, mineral fiber, carbon fiber, ceramic fiber, biodegradable ceramic fiber, rock wool, potassium titanate fiber, silica alumina fiber, and flame resistant fiber. Is mentioned.
  • the inorganic fiber is preferably a fibrous material mainly composed of an inorganic substance other than a metal and a metal alloy, and more preferably a mineral fiber.
  • One type of inorganic fiber may be used alone, or two or more types may be used in combination.
  • Glass fiber refers to a fiber produced by melting and spinning glass.
  • a glass fiber whose raw material is E glass, C glass, S glass, D glass, or the like can be used.
  • a glass containing E glass or S glass from the viewpoint of particularly high strength.
  • fibers are used.
  • glass fibers obtained by treating the surfaces of glass fibers with aminosilane, epoxysilane, or the like are preferable for improving the affinity with the binder.
  • a glass fiber obtained by converging a glass fiber with a urethane resin, an acrylic resin, a phenol resin or the like can be used.
  • the number is preferably 50 to 500 from the viewpoint of the balance between dispersibility and handleability.
  • the average fiber length of the glass fiber is not particularly limited, but is preferably from 80 to 6,000 ⁇ m, more preferably from 150 to 5,000 ⁇ m, still more preferably from 300 to 5,000 ⁇ m, and particularly preferably from 1,000 to 1,000 ⁇ m. 5,000 ⁇ m, and most preferably 2,000-4,000 ⁇ m. If the average fiber length is 80 ⁇ m or more, the strength of the underlay material tends to be improved, and if it is 6,000 ⁇ m or less, a decrease in dispersibility tends to be suppressed.
  • the average fiber diameter of the glass fiber is preferably 5 to 20 ⁇ m, more preferably 7 to 15 ⁇ m.
  • the average fiber diameter is 5 ⁇ m or more, breakage of the glass fiber at the time of mixing the friction material composition for underlining material can be suppressed, and when it is 20 ⁇ m or less, the strength of the underlining material tends to be improved.
  • the average fiber length and the average fiber diameter respectively, randomly select 50 inorganic fibers to be used, measure the fiber length and the fiber diameter with an optical microscope, and show the average value obtained therefrom, If so, you can refer to the catalog value.
  • a fiber diameter points out the diameter of a fiber.
  • the fibrous wollastonite refers to one obtained by pulverizing and classifying a naturally occurring silicate mineral containing CaSiO 3 as a main component and processing it into a fibrous form.
  • the average aspect ratio (average fiber length / average fiber diameter) of the fibrous wollastonite used in the present invention is preferably 8 or more, more preferably 8 to 20, further preferably 9 to 20, and particularly preferably 10 to 20. Eighteen. By setting the average aspect ratio to 8 or more, the shear strength and the crack resistance at room temperature of the underlay material can be effectively improved.
  • the average aspect ratio means a d50 value (cumulative median value of the volume distribution), and can be measured by, for example, a dynamic image analysis method.
  • the average fiber length of the fibrous wollastonite is preferably from 20 to 1,000 ⁇ m, more preferably from 40 to 850 ⁇ m, and still more preferably from 100 to 850 ⁇ m, from the viewpoint of imparting strength to the underlaying material.
  • the average fiber diameter of the fibrous wollastonite is preferably 70 ⁇ m or less, more preferably 60 ⁇ m or less, from the viewpoint of imparting strength to the underlaying material.
  • the lower limit of the average fiber diameter is not particularly limited, but is preferably 5 ⁇ m or more, more preferably 8 ⁇ m or more.
  • the surface of the fibrous wollastonite may be treated with aminosilane, epoxysilane, or the like.
  • the metal fibers include fibers in the form of a single metal or alloy such as aluminum, iron, zinc, tin, titanium, nickel and magnesium, and fibers mainly containing a metal such as cast iron.
  • the alloy-type fiber include an iron alloy fiber and an aluminum alloy fiber.
  • One type of metal fiber may be used alone, or two or more types may be used in combination.
  • a friction material composition for a subbing material containing no metal fibers is preferable. From the viewpoint of improving strength, stabilizing the coefficient of friction, improving thermal conductivity, and improving crack resistance and wear resistance, copper fibers, copper alloy fibers, iron fibers and iron alloy fibers are generally preferred. .
  • the content of copper in the friction material composition for underlaying material is 0.5 mass% as a copper element. %, Preferably 0.3% by mass or less, more preferably 0.1% by mass or less, and further preferably substantially contains no copper.
  • a copper alloy fiber a copper fiber, a brass fiber, a bronze fiber, etc. are mentioned.
  • the iron content in the friction material composition for underlining material is The content of iron is preferably less than 0.5% by mass, more preferably 0.3% by mass or less, further preferably 0.1% by mass or less, and particularly preferably substantially no iron.
  • the mineral fibers are artificial inorganic fibers melt-spun with blast furnace slag such as slag wool, basalt such as basalt fiber, and other natural rocks as main components.
  • the mineral fiber include a mineral fiber containing SiO 2 , Al 2 O 3 , CaO, MgO, FeO, Na 2 O, etc., or a mineral fiber containing one or more of these compounds.
  • a mineral fiber containing an aluminum element is preferred, a mineral fiber containing Al 2 O 3 is more preferred, and a mineral fiber containing Al 2 O 3 and SiO 2 is even more preferred.
  • the shear strength tends to decrease as the average fiber length of the mineral fibers included in the friction material composition for underlining materials increases.
  • the average fiber length of the mineral fibers is preferably 500 ⁇ m or less, more preferably 100 to 400 ⁇ m, and further preferably 120 to 340 ⁇ m.
  • the average fiber diameter (diameter) of the mineral fibers is not particularly limited, but is usually 1 to 20 ⁇ m, and may be 2 to 15 ⁇ m.
  • the mineral fibers are preferably biosoluble from the viewpoint of harmful effects on the human body.
  • biosoluble mineral fiber refers to a mineral fiber that has the characteristic of being partially decomposed in a short time and discharged out of the body even when taken into the human body.
  • the chemical composition is such that the total amount of alkali oxides and alkaline earth oxides (total amount of sodium, potassium, calcium, magnesium and barium oxides) is 18% by mass or more, and (a) short-term inhalation
  • the half-life of a fiber having a length of more than 20 ⁇ m is less than 10 days in an in vivo durability test by exposure, and (b) a half-life of a fiber having a length of more than 20 ⁇ m in an in vivo durability test by short-term intratracheal injection. Less than 40 days, (c) no significant carcinogenicity in the intraperitoneal administration test, or (d) no pathological findings or tumor formation associated with carcinogenicity in the long-term inhalation exposure test.
  • biodegradable mineral fibers include SiO 2 —Al 2 O 3 —CaO—MgO—FeO (—K 2 O—Na 2 O) fibers and the like, and include SiO 2 , Al 2 O 3 , and CaO. , MgO, FeO, K 2 O, Na 2 O and the like.
  • Examples of the carbon fibers include flame-resistant fibers, pitch-based carbon fibers, PAN-based carbon fibers, and activated carbon fibers.
  • One type of carbon fiber may be used alone, or two or more types may be used in combination.
  • the average fiber length of the carbon fibers is not particularly limited, but is preferably 0.1 to 6.0 mm, and more preferably 0.1 to 3.0 mm. When the average fiber length is in the above range, the underlay material is not easily chipped, and the strength is easily maintained.
  • the average fiber diameter of the carbon fibers is not particularly limited, but is preferably 5 to 20 ⁇ m.
  • the content is preferably 3 to 40% by mass, and more preferably 8 to 40% by mass of the friction material composition for underlining material.
  • the content is more preferably 30% by mass, further preferably 10 to 30% by mass, and particularly preferably 15 to 25% by mass.
  • the content of the fibrous base material in the friction material composition for underlining material is preferably 5 to 40% by mass, more preferably 5 to 35% by mass, and still more preferably 15 to 35% by mass in the friction material composition for underlining material. % By mass.
  • the binder has a function of binding and integrating an organic filler, an inorganic filler, a fiber base material, and the like, which can be included in the friction material composition for an underlining material, and giving a predetermined shape and strength.
  • the binder contained in the friction material composition for underlining material of the present invention is not particularly limited, but a thermosetting resin generally used as a binding material for underlining material can be used.
  • the thermosetting resin include a phenol resin, a modified phenol resin, an elastomer-dispersed phenol resin, an epoxy resin, a polyimide resin, and a melamine resin.
  • examples of the modified phenol resin include an acrylic-modified phenol resin, a silicone-modified phenol resin, a cashew-modified phenol resin, an epoxy-modified phenol resin, and an alkylbenzene-modified phenol resin.
  • examples of the elastomer-dispersed phenolic resin include an acrylic elastomer-dispersed phenolic resin and a silicone elastomer-dispersed phenolic resin.
  • a phenol resin, an acryl-modified phenol resin, a silicone-modified phenol resin, and an alkylbenzene-modified phenol resin are preferable, and a phenol resin is more preferable, since they provide good heat resistance, moldability, and friction coefficient.
  • One thermosetting resin may be used alone, or two or more thermosetting resins may be used in combination.
  • the content thereof is preferably 5 to 25% by mass, more preferably 5 to 20% by mass, and still more preferably 6 to 25% by mass in the friction material composition for underlining material. It is preferably from 18 to 18% by mass, particularly preferably from 8 to 16% by mass.
  • the friction material composition for underlining material of the present invention other materials can be blended, if necessary, in addition to the above components.
  • other materials include organic additives such as metal powders such as zinc powder and aluminum; and fluorine-based polymers such as polytetrafluoroethylene (PTFE), from the viewpoint of improving abrasion resistance and thermal fade characteristics.
  • the content is preferably 20% by mass or less, more preferably 10% by mass or less, respectively, in the friction material composition for underlining material.
  • the content is more preferably 5% by mass or less, particularly preferably 3% by mass or less, and may not contain other materials.
  • each component that can be contained in the “friction material composition for overlay” is a component that can be contained in the “friction material (overlay)”.
  • the description of each component in the “friction material composition for overlay” described later can be read as the description of each component in the “overlay material”.
  • the friction material composition for overlay material As the friction material composition for the upper material used as the material of the friction material (upper material) 2, a known friction material composition for the upper material can be used, and there is no particular limitation.
  • the friction material composition for an overlay material examples include a friction material composition for an overlay material containing an organic filler, an inorganic filler, a fiber base material, and a binder.
  • the friction material composition preferably does not contain copper, or even if it contains copper, the content of copper is preferably less than 0.5% by mass as a copper element.
  • the organic filler, the inorganic filler, the fiber base material, and the binder the same ones as described in the above-described friction material composition for underlining material can be used.
  • the friction material composition for an overlay material and the friction material composition for an underlay material of the present invention are molded by a generally used method, preferably by heating and pressing.
  • the upholstery (frictional material) 2 and the lower lining 3 can be integrated.
  • the friction material composition for an overlay material and the friction material composition for an underlay material of the present invention are separately prepared by using a Reidige mixer (“Redige” is a registered trademark), a pressure kneader, an Erich mixer ( “Eirich” is a registered trademark) mixed using a mixer such as, the mixture for the upper material and the mixture for the lower material are pre-formed integrally in a molding die, and then the obtained pre-formed product is, for example, Molding is performed at a molding temperature of 130 to 160 ° C. under a molding pressure of 20 to 50 MPa for 2 to 10 minutes, and the obtained molded product is heat-treated at, for example, 150 to 250 ° C.
  • the mixture may be directly thermoformed without the preforming step.
  • the friction material composition for underlining material of the present invention has high shear strength at room temperature, high crack resistance and excellent abrasion resistance, and furthermore, the durability of the back plate after repeated braking. In order to improve the performance, it can be used as a subbing material 3 for a friction member.
  • the upper lining material (friction material) 2 is a friction material serving as a friction surface of the friction member
  • the lower lining material 3 is formed of an upper lining material (friction material) 2 serving as a friction surface of the friction member and the back plate 1. It is a layer interposed therebetween for the purpose of improving the shear strength and crack resistance near the bonding portion between the overlay material (friction material) 2 and the back plate 1.
  • the friction member of the present invention is a friction member formed by using the underlining material of the present invention so that the upper surface becomes a friction surface, that is, the friction member in which the underlining material is located on the opposite side to the friction surface. It is.
  • the friction member of the present invention is not limited to the above-described embodiment, and includes, for example, (1) a friction material (upper material) 2, a back plate 1, and a lower material 3, and the lower material 3 is provided on the back plate 1.
  • the friction member (same as the above-mentioned embodiment) provided so that the upper material 2 is located on the friction surface side through the intermediary of the back plate 1 and the lower material, 3 and a friction member with a primer layer interposed therebetween for the purpose of surface modification for enhancing the adhesive effect of the back plate 1.
  • a friction member having a shim on the back plate 1 on the side opposite to the side having the underlining material 3 may also be mentioned.
  • the shim is a spacer generally used for improving the vibration damping of the friction member.
  • the thickness of the friction material (overlaying material) 2 is preferably 4 to 15 mm, more preferably 5 to 14 mm, and still more preferably 5 to 12 mm from the viewpoint of durability.
  • the thickness of the underlining material 3 is preferably 1 mm or more, more preferably 1 to 5 mm, and still more preferably 1 to 3 mm.
  • the ratio of the thickness of the underlining material 3 to the total thickness of the uppering material (friction material) 2 and the underlining material 3 is preferably 3 to 70%, and preferably 5 to 60%. More preferably, it is more preferably 6 to 50%.
  • the friction member of the present invention can be used as a friction member for a disc brake pad of an automobile or the like and a friction member for a brake lining of an automobile or the like. Further, the friction material composition for an overlay material and the friction material composition for an underlay material of the present invention are subjected to molding, processing, pasting, and the like into a target shape, so that the friction of a clutch facing, an electromagnetic brake, a holding brake, etc. It can also be used as a member.
  • the friction member of the present invention is suitable as a friction member for a vehicle, because the underlining material can satisfy both the shear strength at normal temperature and the crack resistance and has excellent wear resistance.
  • the present invention also provides a vehicle equipped with the friction member of the present invention.
  • a vehicle equipped with the friction member of the present invention.
  • Examples of the car include large cars, medium cars, ordinary cars, large special cars, small special cars, large motorcycles and ordinary motorcycles.
  • the presence or absence was confirmed and evaluated according to the following evaluation criteria.
  • the temperature of the back plate was measured with a thermocouple embedded in the back plate. a: No breakage of the back plate portion, no deformation exceeding 1 mm, and no occurrence of cracks. b: There was no breakage of the back plate portion and no deformation exceeding 1 mm, but cracks occurred. c: Breakage of the back plate portion or deformation exceeding 1 mm occurred.
  • Examples 1 to 7 and Comparative Example 1 Each component was blended according to the blending amounts shown in Table 1 to obtain a friction material composition for an upholstery material. Further, the respective components were blended in accordance with the blending amounts shown in Table 2 to obtain a friction material composition for an underlining material.
  • the friction material composition for the overlay material and the friction material composition for the underlay material are separately mixed with a “REDIGE (registered trademark) mixer M20” (trade name, manufactured by Matsubo Corporation), and the mixture for the overlay material and the underlay are mixed. A wood mix was obtained.
  • the obtained mixture for the overlay material and the mixture for the underlay material were integrally preformed by a molding press (manufactured by Oji Machine Co., Ltd.).
  • the obtained preformed product was heated together with a back plate of the material shown in Table 2 using a molding press (manufactured by Sanki Seiko Co., Ltd.) under the conditions of a molding temperature of 140 to 160 ° C., a molding pressure of 30 MPa, and a molding time of 5 minutes. It was molded under pressure.
  • the obtained molded article was heat-treated at 200 ° C. for 4.5 hours, polished using a rotary polisher, and scorched at 500 ° C. to obtain a disc brake pad.
  • the disc brake pads obtained in Examples and Comparative Examples had a back plate thickness of 6 mm, an upper material thickness of 6 mm, a lower material thickness of 2 mm, and a friction material projected area of 52 cm 2 . Using the obtained disc brake pads, each measurement and evaluation were performed according to the above-described methods. Table 2 shows the results.
  • Al alloy aluminum alloy
  • A5083 Al-Mg based alloy
  • GFRP phenolic resin composited with 25 mm glass fiber (glass fiber 50% by mass)
  • CFRP phenolic resin composited with 25 mm carbon fiber (50% by mass of carbon fiber)
  • the disc brake pad using a lightweight material having inferior heat resistance for the back plate and using an underlining material containing particles having voids for the underlining material has a high shear strength and The durability of the back plate was high even after repeated braking.
  • the reason why the durability of the back plate has been increased is presumed to be that the temperature rise of the back plate after repeated braking was reduced.
  • Comparative Example 1 using the underlaying material containing no particles having voids the durability of the back plate after repeated braking was significantly reduced.
  • the friction member of the present invention has a small rise in temperature of the back plate even after repeated braking, has practical durability, and is light in weight. Therefore, a disc brake used for braking a two-wheeled or four-wheeled vehicle It is suitable as a pad.

Abstract

The present invention provides a friction member (such as a disc brake pad) which is reduced in weight by reducing the weight of a back plate, and which has improved durability after repeated braking. This friction member is specifically obtained by arranging a friction material (an upper layer material) on one surface of a back plate, which contains a material that has a lighter specific gravity than steel, with a lower layer material being interposed therebetween; and the lower layer material contains particles that have pores.

Description

摩擦部材、下張り材用摩擦材組成物、下張り材、ディスクブレーキパッド及び車Friction member, friction material composition for underlining material, underlining material, disc brake pad and vehicle
　本発明は、摩擦部材、下張り材用摩擦材組成物、下張り材、ディスクブレーキパッド及び車に関する。 The present invention relates to a friction member, a friction material composition for an underlining material, an underlining material, a disc brake pad, and a vehicle.
　二輪車及び四輪の自動車等に取り付けられている制動用の摩擦部材として、ディスクブレーキパッドの一例を図１及び図２に示す。なお、図１はディスクブレーキパッドの上面図であり、図２は図１のＡ－Ａ線における断面図の一例である。本例においては、ディスクブレーキパッドは、バックプレート１と摩擦材２から構成され、摩擦材２がバックプレート１の一方の面１１（ここではバックプレート１の上面）に直接固着されている。摩擦材２は、例えば、結合材、有機充填材、無機充填材及び繊維基材からなる、いわゆるレジンモールド材により構成される。このようなディスクブレーキパッドは、バックプレート１の一方の面に、予め結合材、有機充填材、無機充填材及び繊維基材からなる摩擦材の予備成形体を重ね合わせ、熱圧成形して一体に固着した後、表面加工を施すことにより製造されている。 FIGS. 1 and 2 show an example of a disc brake pad as a friction member for braking attached to a motorcycle or a four-wheeled vehicle. FIG. 1 is a top view of the disc brake pad, and FIG. 2 is an example of a cross-sectional view taken along line AA of FIG. In this example, the disc brake pad is composed of a back plate 1 and a friction material 2, and the friction material 2 is directly fixed to one surface 11 of the back plate 1 (here, the upper surface of the back plate 1). The friction material 2 is made of, for example, a so-called resin mold material including a binder, an organic filler, an inorganic filler, and a fiber base material. In such a disc brake pad, a preform of a friction material composed of a binder, an organic filler, an inorganic filler, and a fiber base material is preliminarily superimposed on one surface of the back plate 1 and then hot-pressed to form an integrated body. It is manufactured by applying a surface treatment after being fixed to the surface.
　また、ディスクブレーキパッドの他の例を図３に示す。図３は図１のＡ－Ａ線における断面図の他の例である。図３のディスクブレーキパッドは、バックプレート１、摩擦材（図３の場合は上張り材とも称する。）２及び下張り材３から構成され、バックプレート１の一方の面１１（ここではバックプレート１の上面）に、下張り材３を介して摩擦材（上張り材）２が固着されたものである。この場合、ディスクブレーキパッドは、バックプレート１の一方の面に、予め結合材、有機充填材、無機充填材及び繊維基材からなる摩擦材及び下張り材の予備成形体を重ね合わせ、熱圧成形して一体に固着した後、表面加工を施すことにより製造されている。 FIG. 3 shows another example of the disc brake pad. FIG. 3 is another example of a cross-sectional view taken along line AA of FIG. The disc brake pad of FIG. 3 includes a back plate 1, a friction material (also referred to as an upper material in FIG. 3) 2 and a lower material 3, and one surface 11 of the back plate 1 (here, the back plate 1). A friction material (upper material) 2 is fixed to a lower surface material 3 via a lower material 3. In this case, the disc brake pad is preliminarily laminated on one surface of the back plate 1 with a preformed body of a friction material and an underlay material composed of a binder, an organic filler, an inorganic filler and a fiber base material, and then hot-pressed. It is manufactured by performing surface processing after being fixed integrally.
　近年、自動車の環境対応化及び低燃費化の進行に伴い、自動車の各部品の軽量化が検討及び実施されている。通常、自動車における原材料の構成は、金属材が半分以上を占めているが、車体の軽量化のため、その使用量は年々低下傾向にある。また、車体の軽量化にあたっては、近年、素材としてアルミニウム（アルミニウム合金又はアルミニウム複合材）又は樹脂の使用が増加傾向にある。鋼板の比重は約７．８Ｍｇ／ｍ３であり、これに比べてアルミニウムの比重は約２．７Ｍｇ／ｍ３、樹脂の比重は約１Ｍｇ／ｍ３であって軽いため、アルミニウム及び樹脂等の素材を使用することにより、車体の５０％以下の軽量化が見込める。このような軽量化への動きの中、車両においては、ボディ、フレームのみならず、車両を構成する各要素に対しても軽量化の要求が大きくなってきている。 2. Description of the Related Art In recent years, with the advancement of environmental friendliness and low fuel consumption of automobiles, reduction in weight of each component of the automobile has been studied and implemented. Usually, metal materials occupy more than half of the composition of raw materials in automobiles. However, the amount of use is decreasing year by year due to weight reduction of vehicle bodies. Further, in reducing the weight of a vehicle body, in recent years, the use of aluminum (aluminum alloy or aluminum composite material) or resin as a material has been increasing. The specific gravity of steel sheet is about 7.8 mg / m 3, the specific gravity of aluminum is about 2.7 Mg / m 3 as compared to, lighter specific gravity of the resin is from about 1 Mg / m 3, such as aluminum and resin By using a material, a weight reduction of 50% or less of the vehicle body can be expected. In such a movement to reduce the weight, in the vehicle, not only the body and the frame, but also the demands for the weight reduction of each element constituting the vehicle are increasing.
　このような車体軽量化の要求は、車両の制動に用いられるブレーキシステムの構成要素の一つであるディスクブレーキパッドにおいても同様に大きくなってきている。具体的には、従来、ディスクブレーキパッドには鋼製の板材からなるバックプレートが用いられていたが、近年では樹脂製のバックプレートの提案がなされており、例えば、０．１～１０ｍｍ程度のガラス繊維を含有したフェノール樹脂を圧縮成形したもの（例えば、特許文献１及び２参照）等が提案されている。 要求 The demand for such a reduction in the weight of the vehicle body is also increasing in a disc brake pad which is one of the components of a brake system used for braking the vehicle. Specifically, conventionally, a back plate made of a steel plate material has been used for a disc brake pad, but in recent years, a back plate made of a resin has been proposed. There have been proposed, for example, those obtained by compression-molding a phenol resin containing glass fibers (for example, see Patent Documents 1 and 2).
特開２００１－１６５２１０号公報JP 2001-165210 A 特開２００１－２５３９９８号公報JP 2001-253998 A
　本発明者らは、ディスクブレーキパッドの軽量化のため、バックプレートをこれまでの鋼製のものから、樹脂製又はアルミニウム製等の軽量化素材に変更することを検討していたところ、これらの軽量化素材は、従来の鋼製のバックプレートに比べて繰り返し制動後の耐久性が不十分であることが判明した。 The present inventors have been studying to change the back plate from a conventional steel-made one to a light-weight material such as resin or aluminum in order to reduce the weight of the disc brake pad. It has been found that the lightweight material has insufficient durability after repeated braking compared to the conventional steel back plate.
　これらのことから、本発明は、バックプレートの軽量化によって摩擦部材（ディスクブレーキパッド等）の軽量化を図ると共に、繰り返し制動後の耐久性が改善された摩擦部材を提供することを目的とする。 Accordingly, it is an object of the present invention to reduce the weight of a friction member (such as a disc brake pad) by reducing the weight of a back plate and to provide a friction member having improved durability after repeated braking. .
　本発明者らは、上記の課題を解決すべく鋭意研究した結果、下張り材に特定の粒子を含有させることによって、バックプレートを軽量化したときにも繰り返し制動後のバックプレートの耐久性が改善され、ひいては繰り返し制動後の摩擦部材の耐久性が改善され得ることを見出し、本発明を完成するに至った。本発明は、係る知見に基づいて完成したものである。 The present inventors have conducted intensive studies to solve the above-mentioned problems, and as a result, by including specific particles in the underlining material, the durability of the back plate after repeated braking is improved even when the back plate is reduced in weight. As a result, it has been found that the durability of the friction member after repeated braking can be improved, and the present invention has been completed. The present invention has been completed based on such findings.
　本発明は下記［１］～［１６］に関する。
［１］鋼より比重の軽い素材を含有するバックプレートの一方の面に摩擦材（上張り材）が下張り材を介して配置された摩擦部材であって、前記下張り材が空隙を有する粒子を含有する摩擦部材。
［２］前記空隙を有する粒子の空隙率が３０体積％以上である、上記［１］に記載の摩擦部材。
［３］前記空隙を有する粒子が、フライアッシュバルーン、シラスバルーン、珪藻土、中空ガラス粒子、ケイ酸カルシウム粒子、中空シリカ粒子、アルミナバルーン、ジルコニアバルーン、γ－アルミナ粒子及びフェノール樹脂バルーンからなる群から選択される少なくとも１種である、上記［１］又は［２］に記載の摩擦部材。
［４］前記下張り材における前記空隙を有する粒子の含有量が０．１～３０質量％である、上記［１］～［３］のいずれかに記載の摩擦部材。
［５］前記バックプレートが含有する素材の比重が５Ｍｇ／ｍ３以下である、上記［１］～［４］のいずれかに記載の摩擦部材。
［６］前記バックプレートが、（１）繊維強化樹脂、（２－１）アルミニウム合金、（２－２）アルミニウムもしくはアルミニウム合金中にセラミックス粒子が分散するアルミニウム複合材、（３－１）マグネシウム合金、及び（３－２）マグネシウムもしくはマグネシウム合金中にセラミックス粒子が分散するマグネシウム複合材、からなる群から選択される少なくとも１種を含有する、上記［１］～［５］のいずれかに記載の摩擦部材。
［７］前記バックプレートが前記（１）繊維強化樹脂又は前記（２－１）アルミニウム合金を含有する、上記［６］に記載の摩擦部材。
［８］上記［１］～［７］のいずれかに記載の摩擦部材を含むディスクブレーキパッド。
［９］上記［１］～［７］のいずれかに記載の摩擦部材を搭載した車。
［１０］空隙を有する粒子を含有する、下張り材用摩擦材組成物。
［１１］前記空隙を有する粒子の空隙率が３０体積％以上である、上記［１０］に記載の下張り材用摩擦材組成物。
［１２］前記空隙を有する粒子が、フライアッシュバルーン、シラスバルーン、珪藻土、中空ガラス粒子、ケイ酸カルシウム粒子、中空シリカ粒子、アルミナバルーン、ジルコニアバルーン、γ－アルミナ粒子及びフェノール樹脂バルーンからなる群から選択される少なくとも１種である、上記［１０］又は［１１］に記載の下張り材用摩擦材組成物。
［１３］さらに有機充填材、無機充填材、繊維基材及び結合材からなる群から選択される少なくとも１種を含有する、上記［１０］～［１２］のいずれかに記載の下張り材用摩擦材組成物。
［１４］銅を含有しないか、又は含有していても銅の含有量は銅元素として０．５質量％未満である、上記［１０］～［１３］のいずれかに記載の下張り材用摩擦材組成物。
［１５］上記［１０］～［１４］のいずれかに記載の下張り材用摩擦材組成物を成形してなる下張り材。
［１６］上記［１５］に記載の下張り材を搭載した車。 The present invention relates to the following [1] to [16].
[1] A friction member in which a friction material (upper material) is disposed on one surface of a back plate containing a material having a specific gravity lower than that of steel via a lower material, wherein the lower material has particles having voids. Friction member to contain.
[2] The friction member according to [1], wherein the porosity of the particles having voids is 30% by volume or more.
[3] The particles having voids are selected from the group consisting of fly ash balloons, shirasu balloons, diatomaceous earth, hollow glass particles, calcium silicate particles, hollow silica particles, alumina balloons, zirconia balloons, γ-alumina particles, and phenol resin balloons. The friction member according to the above [1] or [2], which is at least one selected from the group.
[4] The friction member according to any one of [1] to [3], wherein the content of the particles having voids in the underlining material is 0.1 to 30% by mass.
[5] The friction member according to any of [1] to [4], wherein the specific gravity of the material contained in the back plate is 5 Mg / m 3 or less.
[6] The back plate is made of (1) a fiber-reinforced resin, (2-1) an aluminum alloy, (2-2) an aluminum composite material in which ceramic particles are dispersed in aluminum or an aluminum alloy, and (3-1) a magnesium alloy. And (3-2) a magnesium composite material in which ceramic particles are dispersed in magnesium or a magnesium alloy, and at least one selected from the group consisting of: Friction member.
[7] The friction member according to the above [6], wherein the back plate contains the (1) fiber-reinforced resin or the (2-1) aluminum alloy.
[8] A disc brake pad including the friction member according to any one of [1] to [7].
[9] A vehicle equipped with the friction member according to any one of [1] to [7].
[10] A friction material composition for a subbing material, comprising particles having voids.
[11] The friction material composition for an underlining material according to the above [10], wherein the particles having voids have a porosity of 30% by volume or more.
[12] The particles having voids are selected from the group consisting of fly ash balloons, shirasu balloons, diatomaceous earth, hollow glass particles, calcium silicate particles, hollow silica particles, alumina balloons, zirconia balloons, γ-alumina particles, and phenol resin balloons. The friction material composition for underlining material according to the above [10] or [11], which is at least one selected from the group consisting of:
[13] The friction for underlining materials according to any of [10] to [12], further comprising at least one selected from the group consisting of an organic filler, an inorganic filler, a fiber base material, and a binder. Material composition.
[14] The friction for underlining materials according to any of [10] to [13] above, wherein copper is not contained, or even if copper is contained, the copper content is less than 0.5% by mass as a copper element. Material composition.
[15] An underlining material obtained by molding the friction material composition for an underlining material according to any one of [10] to [14].
[16] A vehicle equipped with the underlining material according to the above [15].
　本発明によれば、バックプレートの軽量化によって摩擦部材（ディスクブレーキパッド等）の軽量化を図ると共に、繰り返し制動後の耐久性が改善された摩擦部材を提供することができる。また、バックプレートの比重が鋼より小さいため、ディスクブレーキパッド等の摩擦部材の軽量化を図ることで、二輪車及び四輪の自動車等の車体の軽量化に寄与する。 According to the present invention, it is possible to reduce the weight of the friction member (such as a disc brake pad) by reducing the weight of the back plate, and to provide a friction member having improved durability after repeated braking. Further, since the specific gravity of the back plate is smaller than steel, the weight of friction members such as disc brake pads is reduced, thereby contributing to the weight reduction of vehicle bodies such as motorcycles and four-wheeled vehicles.
摩擦部材（ディスクブレーキパッド）を示す模式図（上面図）である。It is a schematic diagram (top view) showing a friction member (disk brake pad). バックプレートの一方の面に摩擦材が直接配置された摩擦部材（ディスクブレーキパッド）の図１におけるＡ－Ａ断面の模式図である。FIG. 2 is a schematic view of a friction member (disk brake pad) in which a friction material is directly arranged on one surface of a back plate, taken along a line AA in FIG. 1. バックプレートの一方の面に摩擦材（上張り材）が下張り材を介して配置された摩擦部材（ディスクブレーキパッド）の図１におけるＡ－Ａ断面の模式図である。FIG. 2 is a schematic cross-sectional view of the friction member (disc brake pad) in which a friction material (upper material) is disposed on one surface of a back plate via a lower material, taken along the line AA in FIG. 1.
　以下、本発明について詳細に説明する。但し、以下の実施形態において、その構成要素は、特に明示した場合を除き、必須ではない。数値及びその範囲についても同様であり、本発明を制限するものではない。
　本明細書中に記載されている数値範囲において、その数値範囲の上限値又は下限値は、実施例に示されている値に置き換えてもよい。さらに、本明細書において、下張り材又は下張り材用摩擦材組成物中の各成分の含有率は、各成分に該当する物質が複数種存在する場合には、特に断らない限り、下張り材又は下張り材用摩擦材組成物中に存在する当該複数種の物質の合計の含有率を意味する。
　また、本明細書における記載事項を任意に組み合わせた態様も本発明に含まれる。 Hereinafter, the present invention will be described in detail. However, in the following embodiments, the components are not essential unless otherwise specified. The same applies to numerical values and their ranges, and does not limit the present invention.
In the numerical ranges described in this specification, the upper limit or the lower limit of the numerical range may be replaced with the value shown in the embodiment. Furthermore, in the present specification, the content of each component in the underlining material or the friction material composition for the underlining material, when there are a plurality of types of substances corresponding to each component, unless otherwise specified, It means the total content of the plurality of types of substances present in the material friction material composition.
In addition, embodiments in which the items described in this specification are arbitrarily combined are also included in the present invention.
　本発明者らの検討により、制動を繰り返すと、摩擦熱によってブレーキ温度が上昇し、摩擦材の表面温度が約６００℃以上となる場合があり、特に摩擦材が摩耗して摩擦材の残厚が少なくなった場合に、バックプレートが２５０℃以上まで昇温することがあることがわかった。また、軽量化素材の中でも繊維強化樹脂によって形成されたバックプレートでは、樹脂の耐熱温度以上にバックプレートの温度が上がると樹脂が熱分解し、バックプレートの強度が著しく低下し、クラックの発生及び割れといった不具合が生じ易くなることが判明した。アルミニウム合金、アルミニウム複合材、マグネシウム合金、マグネシウム複合材等の軽量化素材により形成されたバックプレートでは、２５０℃以上で、強度及び弾性率が著しく低下し、変形及び破壊といった不具合が生じ易くなることが判明した。しかし、本発明の態様であれば、軽量化素材からなるバックプレート１の温度上昇が抑制され、摩擦材２の表面温度が６００℃以上となる場合においても、バックプレート１のクラック及び割れを防止することができ、摩擦部材について、軽量化と、繰り返し制動後の耐久性との両立が可能となった。 According to the study of the present inventors, when braking is repeated, the brake temperature rises due to frictional heat, and the surface temperature of the friction material may be about 600 ° C. or more. It was found that the temperature of the back plate may rise to 250 ° C. or more when the amount of decreased. In the case of a back plate made of fiber reinforced resin among the lightweight materials, when the temperature of the back plate rises above the heat resistant temperature of the resin, the resin is thermally decomposed, the strength of the back plate is significantly reduced, and cracks and It has been found that defects such as cracks are likely to occur. Backplates made of lightweight materials such as aluminum alloys, aluminum composites, magnesium alloys, magnesium composites, and the like, at 250 ° C or higher, have significantly reduced strength and elastic modulus, and are liable to cause problems such as deformation and breakage. There was found. However, according to the aspect of the present invention, the temperature rise of the back plate 1 made of a lightweight material is suppressed, and even when the surface temperature of the friction material 2 becomes 600 ° C. or more, cracks and cracks of the back plate 1 are prevented. As a result, it is possible to reduce the weight of the friction member and to achieve the durability after repeated braking.
　本発明の一態様は図３を用いて説明される。鋼より比重の軽い素材を含有するバックプレート１の一方の面に摩擦材（上張り材）２が下張り材３を介して配置された摩擦部材であって、前記下張り材３が空隙を有する粒子を含有する摩擦部材である。
　まず、バックプレート１について詳述する。 One embodiment of the present invention is described with reference to FIG. A friction member in which a friction material (upper material) 2 is disposed on one surface of a back plate 1 containing a material having a specific gravity lower than that of steel with an under material 3 interposed therebetween, wherein the under material 3 is a particle having voids. Is a friction member.
First, the back plate 1 will be described in detail.
［バックプレート］
　バックプレートは鋼より比重の軽い素材を含有するものである。該バックプレートは鋼より比重の軽い素材を好ましくは５０体積％以上、より好ましくは８０体積％以上、さらに好ましくは９０体積％以上含有するものであり、鋼より比重の軽い素材からなるものであることが特に好ましい。鋼より比重の軽い素材は、好ましくは比重５Ｍｇ／ｍ３以下の素材であり、より好ましくは比重３Ｍｇ／ｍ３以下の素材であり、さらに好ましくは比重２Ｍｇ／ｍ３以下の素材である。さらには、バックプレートの比重が５Ｍｇ／ｍ３以下であることが好ましく、３Ｍｇ／ｍ３以下であることがより好ましく、２Ｍｇ／ｍ３以下であることがさらに好ましい。 [Back plate]
The back plate contains a material having a lower specific gravity than steel. The back plate contains a material having a specific gravity lower than that of steel, preferably 50% by volume or more, more preferably 80% by volume or more, and still more preferably 90% by volume or more, and is made of a material having a specific gravity lower than steel. Is particularly preferred. The material having a specific gravity lower than that of steel is preferably a material having a specific gravity of 5 Mg / m 3 or less, more preferably a material having a specific gravity of 3 Mg / m 3 or less, and still more preferably a material having a specific gravity of 2 Mg / m 3 or less. Further, it is preferable that the specific gravity of the back plate is 5 mg / m 3 or less, more preferably 3Mg / m 3 or less, and more preferably 2Mg / m 3 or less.
　鋼より比重の軽い素材としては、例えば、（１）繊維強化樹脂、（２－１）アルミニウム合金、（２－２）アルミニウムもしくはアルミニウム合金中にセラミックス粒子が分散するアルミニウム複合材、（３－１）マグネシウム合金、及び（３－２）マグネシウムもしくはマグネシウム合金中にセラミックス粒子が分散するマグネシウム複合材等が挙げられる。つまり、バックプレートは、前記素材（１）、（２－１）、（２－２）、（３－１）及び（３－２）からなる群から選択される少なくとも１種を含有するものであってもよく、前記素材（１）、（２－１）、（２－２）、（３－１）及び（３－２）からなる群から選択される少なくとも１種からなるものであってもよい。これらの中でも、鋼より比重の軽い素材としては（１）繊維強化樹脂、（２－１）アルミニウム合金が好ましく、（１）繊維強化樹脂であってもよいし、（２－１）アルミニウム合金であってもよい。 Examples of the material having a lower specific gravity than steel include (1) fiber-reinforced resin, (2-1) aluminum alloy, (2-2) aluminum or an aluminum composite material in which ceramic particles are dispersed in aluminum or an aluminum alloy, (3-1) And (3-2) magnesium or a magnesium composite material in which ceramic particles are dispersed in a magnesium alloy. In other words, the back plate contains at least one selected from the group consisting of the materials (1), (2-1), (2-2), (3-1) and (3-2). And at least one selected from the group consisting of the above-mentioned materials (1), (2-1), (2-2), (3-1) and (3-2), Is also good. Among them, materials having a lower specific gravity than steel are preferably (1) fiber reinforced resin and (2-1) aluminum alloy, (1) fiber reinforced resin or (2-1) aluminum alloy. There may be.
（（１）繊維強化樹脂）
　繊維強化樹脂とは、繊維と樹脂とを複合化したもの、つまり繊維と樹脂との複合材を指す。繊維強化樹脂の比重は約１Ｍｇ／ｍ３程度であるため軽量化素材として好適である。 ((1) Fiber reinforced resin)
The fiber-reinforced resin refers to a composite of fiber and resin, that is, a composite of fiber and resin. Since the specific gravity of the fiber reinforced resin is about 1 Mg / m 3, it is suitable as a lightweight material.
　繊維強化樹脂に用いられる繊維としては、例えば、ガラス繊維、α－アルミナタイプ、γ－アルミナタイプ等のアルミナ繊維、ボロン繊維等の無機繊維；パラ系アラミド繊維、メタ系アラミド繊維等のアラミド繊維；セルロース繊維、ナノセルロース繊維、ＰＢＯ（ポリパラフェニレンベンズオキサゾール）繊維、又は耐炎化繊維、ピッチ系、ＰＡＮ（ポリアクリロニトリル）系の炭素繊維等の炭素系繊維、からなる群から選ばれる少なくとも１種を用いることができる。特にバックプレートとして用いる場合、強度及び剛性の観点から、ガラス繊維、炭素繊維が好ましく、高熱伝導率の観点から、炭素繊維がさらに好ましい。炭素繊維を用いることで、バックプレートの熱伝導率をより一層向上することができ、繰り返し制動を行い摩擦熱でブレーキ温度が上昇したときに、バックプレート内の温度分布を均一にすることができ、局所的な温度上昇を防ぎ、樹脂の熱分解及び強度低下に伴うクラック、割れを防止し易い傾向にある。 Examples of the fiber used for the fiber-reinforced resin include glass fiber, alumina fiber such as α-alumina type and γ-alumina type, and inorganic fiber such as boron fiber; aramid fiber such as para-aramid fiber and meta-aramid fiber; At least one selected from the group consisting of cellulose fibers, nanocellulose fibers, PBO (polyparaphenylenebenzoxazole) fibers, or oxidized fibers, pitch-based fibers, and carbon-based fibers such as PAN (polyacrylonitrile) -based carbon fibers; Can be used. Particularly when used as a back plate, glass fibers and carbon fibers are preferred from the viewpoint of strength and rigidity, and carbon fibers are more preferred from the viewpoint of high thermal conductivity. By using carbon fiber, the thermal conductivity of the back plate can be further improved, and when the braking temperature is increased by frictional heat due to repeated braking, the temperature distribution in the back plate can be made uniform. In addition, there is a tendency that a local temperature rise is prevented, and cracks and cracks due to thermal decomposition and a decrease in strength of the resin are easily prevented.
　前記繊維強化樹脂に用いられる繊維の繊維長は特に制限されないが、強度の観点から、１ｍｍ以上の繊維長が好ましく、１０ｍｍ以上の長繊維であることがさらに好ましい。該繊維の繊維長の上限値に特に制限はなく、１００ｍｍ以下であってもよいし、７０ｍｍ以下であってもよいし、５０ｍｍ以下であってもよいし、３５ｍｍ以下であってもよい。
　また、前記繊維強化樹脂に用いる繊維としては、フェルト等の不織布、抄造品、連続繊維から成る織物、編物、交織物等の織布も用いることができる。 The fiber length of the fiber used in the fiber reinforced resin is not particularly limited, but from the viewpoint of strength, a fiber length of 1 mm or more is preferable, and a long fiber of 10 mm or more is more preferable. The upper limit of the fiber length of the fiber is not particularly limited, and may be 100 mm or less, 70 mm or less, 50 mm or less, or 35 mm or less.
Further, as the fiber used for the fiber reinforced resin, a nonwoven fabric such as a felt, a paper product, a woven fabric composed of continuous fibers, a knitted fabric, and a woven fabric such as a mixed fabric can also be used.
　前記繊維強化樹脂に用いられる樹脂としては、耐熱性の観点から、熱硬化性樹脂が好ましく、耐熱性及び強度の観点から、フェノール樹脂、エポキシ樹脂、ポリイミド樹脂が好ましい。前記フェノール樹脂及びエポキシ樹脂は、ノボラック型、レゾール型のいずれも使用することができる。前記エポキシ樹脂又は前記フェノールがノボラック型の場合、硬化剤を併用することが好ましい。繊維強化樹脂に用いられる樹脂は、１種を単独で使用してもよいし、２種以上を併用してもよい。フェノール樹脂としては、市販品の使用も可能であり、常法により合成することもできる。 樹脂 As the resin used for the fiber reinforced resin, a thermosetting resin is preferable from the viewpoint of heat resistance, and a phenol resin, an epoxy resin, and a polyimide resin are preferable from the viewpoint of heat resistance and strength. As the phenol resin and the epoxy resin, any of a novolak type and a resol type can be used. When the epoxy resin or the phenol is a novolak type, it is preferable to use a curing agent in combination. As the resin used for the fiber reinforced resin, one type may be used alone, or two or more types may be used in combination. As the phenol resin, a commercially available product can be used, and the phenol resin can be synthesized by a conventional method.
　前記フェノール樹脂としては、レゾール型フェノール樹脂、ストレートノボラック型フェノール樹脂、アラルキル変性型フェノール樹脂、アクリルエラストマー、シリコーンエラストマー等で変性したエラストマー変性型フェノール樹脂等が挙げられる。耐熱性の観点から、フェノール樹脂としては、ストレートノボラック型フェノール樹脂、レゾール型フェノール樹脂が好ましい。 Examples of the phenol resin include a resol-type phenol resin, a straight novolak-type phenol resin, an aralkyl-modified phenol resin, an elastomer-modified phenol resin modified with an acrylic elastomer, a silicone elastomer, and the like. From the viewpoint of heat resistance, a straight novolak type phenol resin or a resol type phenol resin is preferable as the phenol resin.
　また、前記エポキシ樹脂としては、市販品の使用も可能であり、常法により合成することもできる。エポキシ樹脂としては、強度及び耐熱性の観点から、芳香環を有するエポキシ樹脂であることが好ましい。具体的には、フェノールノボラック型エポキシ樹脂、クレゾールノボラック型エポキシ樹脂、ナフタレン型エポキシ樹脂等を好適に使用することができる。また、シリコーン、アクリロニトリル、ブタジエン、イソプロピル系ゴム、ポリアミド系樹脂等により変性したエポキシ樹脂等についても使用することができる。 市 販 Also, as the epoxy resin, a commercially available product can be used, and the epoxy resin can be synthesized by an ordinary method. The epoxy resin is preferably an epoxy resin having an aromatic ring from the viewpoint of strength and heat resistance. Specifically, a phenol novolak type epoxy resin, a cresol novolak type epoxy resin, a naphthalene type epoxy resin, or the like can be suitably used. Further, epoxy resin modified with silicone, acrylonitrile, butadiene, isopropyl rubber, polyamide resin, or the like can also be used.
　また、前記繊維強化樹脂においては、上記の繊維及び樹脂以外に、その他の添加剤を配合することができる。その他の添加剤としては、無機充填材、有機充填材、金属粉等が挙げられる。その他の添加剤は、１種を単独で使用してもよいし、２種以上を併用してもよい。粒子状の無機充填材、有機充填材、金属粉であることが好ましく、繊維集合体中に分散させるためには粒子径が小さいことが好ましい。具体的には、摺動性を向上させる観点からは、黒鉛、二硫化モリブデン、硫化タングステン、フッ素樹脂及びコークス等が挙げられ、難燃性を向上させる観点からは、水酸化マグネシウム、水酸化アルミニウム及びアンチモン化合物等が挙げられ、軽量化の観点からは、中空無機粒子等が挙げられ、樹脂の硬化速度を向上させる観点からは、酸化カルシウム、水酸化カルシウム等が挙げられ、熱伝導率を向上させる観点からは、金属粉、黒鉛、酸化マグネシウム、酸化亜鉛等が挙げられる。 In the fiber reinforced resin, other additives can be blended in addition to the fibers and the resin. Other additives include inorganic fillers, organic fillers, metal powders and the like. As the other additives, one kind may be used alone, and two kinds or more may be used in combination. It is preferably a particulate inorganic filler, organic filler, or metal powder. In order to disperse the filler in the fiber aggregate, the particle diameter is preferably small. Specifically, from the viewpoint of improving slidability, graphite, molybdenum disulfide, tungsten sulfide, fluororesin, coke, and the like are mentioned. From the viewpoint of improving flame retardancy, magnesium hydroxide and aluminum hydroxide are used. And antimony compounds, etc., from the viewpoint of weight reduction, hollow inorganic particles, etc., from the viewpoint of improving the curing speed of the resin, calcium oxide, calcium hydroxide, etc., to improve the thermal conductivity From the point of view, metal powder, graphite, magnesium oxide, zinc oxide and the like can be mentioned.
　前記繊維強化樹脂は、バックプレートの局所的な温度上昇を防ぐために、厚み方向の熱伝導率が０．３０Ｗ／ｍ・Ｋ以上であることが好ましく、０．３５Ｗ／ｍ・Ｋ以上であることがより好ましく、０．４０Ｗ／ｍ・Ｋ以上であることがさらに好ましい。前記繊維強化樹脂の厚み方向の熱伝導率を前記範囲にする方法としては、前記金属粉、黒鉛、酸化マグネシウム、酸化亜鉛等の熱伝導率の高い添加剤を繊維強化樹脂に添加する方法、繊維強化樹脂の繊維として炭素繊維等の熱伝導率の高い繊維を用いる方法などが挙げられ、これらの方法を１種単独で又は２種以上の組合せで採用した繊維強化樹脂を用いることができる。
　なお、本発明において、厚み方向とは、相手材と摺接する摩擦材の表面からバックプレートへの方向であり、熱伝導率は、室温（２５℃）において温度傾斜法で測定される熱伝導率である。ここで、温度傾斜法とは、温度差のある２つの物体に接した試料が定常状態に達したときに、その熱流束と試料温度から試料の熱伝導率を測定する方法であり、温度傾斜法で測定される熱伝導率は、市販の測定装置を用いて測定することができる。温度傾斜法で測定される熱伝導率としては、具体的には、実施例に記載の方法によって測定される熱伝導率である。 The fiber reinforced resin preferably has a thermal conductivity in the thickness direction of 0.30 W / m · K or more, and 0.35 W / m · K or more, in order to prevent a local temperature rise of the back plate. Is more preferable, and more preferably 0.40 W / mK or more. As a method for setting the thermal conductivity in the thickness direction of the fiber reinforced resin to the above range, a method of adding an additive having a high thermal conductivity such as the metal powder, graphite, magnesium oxide, and zinc oxide to the fiber reinforced resin, As a fiber of the reinforced resin, a method using a fiber having a high thermal conductivity such as a carbon fiber may be used, and a fiber reinforced resin employing one of these methods alone or a combination of two or more thereof may be used.
In the present invention, the thickness direction is the direction from the surface of the friction material slidingly contacting the mating material to the back plate, and the thermal conductivity is the thermal conductivity measured at room temperature (25 ° C.) by a temperature gradient method. It is. Here, the temperature gradient method is a method of measuring the thermal conductivity of a sample from the heat flux and the sample temperature when the sample in contact with two objects having a temperature difference reaches a steady state. The thermal conductivity measured by the method can be measured using a commercially available measuring device. Specifically, the thermal conductivity measured by the temperature gradient method is the thermal conductivity measured by the method described in the examples.
　バックプレートに前記繊維強化樹脂を用いる場合、繊維強化樹脂を成形し、必要に応じて形状加工を施すことによって繊維強化樹脂製のバックプレートを製作した後、繊維強化樹脂製バックプレートを従来の鋼製のバックプレートに替えて用いることで、上記の摩擦部材を製造することができる。すなわち、摩擦材の熱成形金型の型孔に必要に応じて予備成形を行った摩擦材組成物を挿入し、次いで、前記予備成形体に接して前記繊維強化樹脂からなるバックプレートに予め接着剤を塗布したものを配置する。そして、摩擦材組成物を熱成形して摩擦材（上張り材）及び下張り材を形成することで前記繊維強化樹脂と摩擦材とを下張り材を介して一体化し、摩擦部材を形成することができる。以上の工程によると、前記繊維強化樹脂からなるバックプレートの熱成形と、摩擦材（上張り材）及び下張り材の熱成形とを別に行うことから、エネルギー効率が必ずしも良いとは言えない。そこで、繊維強化樹脂からなるバックプレートの熱成形と、摩擦材（上張り材）及び下張り材の熱成形を同時に行うことにより、エネルギー効率を高めることもできる。すなわち、熱硬化前の状態の繊維強化樹脂と、必要に応じて予備成形を行った摩擦材組成物とを挿入し、同時に熱成形を行い、熱成形の工程において前記繊維強化樹脂中の熱硬化性樹脂と摩擦材中の熱硬化性樹脂が溶融及び硬化することで、接着材の必要なく一体化することができる。 When the fiber reinforced resin is used for the back plate, the fiber reinforced resin is molded and, if necessary, shaped to produce a fiber reinforced resin back plate. The above friction member can be manufactured by using it instead of the back plate made of. That is, the preformed friction material composition is inserted into the mold hole of the thermoforming mold of the friction material as necessary, and then is adhered to the back plate made of the fiber reinforced resin in contact with the preformed body. The thing which applied the agent is arranged. Then, the friction material composition is thermoformed to form a friction material (upper material) and a lower material, whereby the fiber reinforced resin and the friction material are integrated via the lower material to form a friction member. it can. According to the above steps, the thermoforming of the back plate made of the fiber reinforced resin and the thermoforming of the friction material (upper material) and the lower material are performed separately, so that the energy efficiency is not necessarily good. Therefore, energy efficiency can be improved by simultaneously performing thermoforming of the back plate made of the fiber reinforced resin and thermoforming of the friction material (upper material) and the lower material. That is, the fiber reinforced resin in a state before the thermosetting and the friction material composition which has been preformed as necessary are inserted, and simultaneously thermoformed, and the thermosetting in the fiber reinforced resin in the thermoforming step is performed. By melting and hardening the thermosetting resin and the thermosetting resin in the friction material, they can be integrated without the need for an adhesive.
（アルミニウム、アルミニウム合金）
　アルミニウムは比重が約２．７Ｍｇ／ｍ３と小さいため、軽量化素材として好適であるが、強度の観点から、バックプレートとしてはアルミニウム合金を用いることが好ましい。アルミニウム合金としては、２ＸＸＸ系（Ａｌ－Ｃｕ系）、３ＸＸＸ系（Ａｌ－Ｍｎ系）、４ＸＸＸ系（Ａｌ－Ｓｉ系）、５ＸＸＸ系（Ａｌ－Ｍｇ系）、６ＸＸＸ系（Ａｌ－Ｍｇ－Ｓｉ系）、７ＸＸＸ系（Ａｌ－Ｚｎ系）等の展伸用アルミニウム合金；ＡＣ１Ｃ（Ａｌ－Ｃｕ系）、ＡＣ１Ｂ（Ａｌ－Ｃｕ系）、ＡＣ２Ａ（Ａｌ－Ｃｕ－Ｓｉ系）、ＡＣ２Ｂ（Ａｌ－Ｃｕ－Ｓｉ系）、ＡＣ３Ａ（Ａｌ－Ｓｉ系）、ＡＣ４Ａ、ＡＣ４Ｃ（Ａｌ－Ｓｉ－Ｍｇ系）、ＡＣ４Ｂ（Ａｌ－Ｓｉ－Ｃｕ系）、ＡＣ４Ｄ（Ａｌ－Ｓｉ－Ｃｕ－Ｍｇ系）、ＡＣ５Ａ（Ａｌ－Ｃｕ－Ｎｉ－Ｍｇ系）、ＡＣ７Ａ（Ａｌ－Ｍｇ系）、ＡＣ８Ａ（Ａｌ－Ｓｉ－Ｃｕ－Ｎｉ－Ｍｇ系）、ＡＣ８Ｂ（Ａｌ－Ｓｉ－Ｃｕ－Ｎｉ－Ｍｇ系）、ＡＣ９Ａ（Ａｌ－Ｓｉ－Ｃｕ－Ｍｇ系）、ＡＣ９Ｂ（Ａｌ－Ｓｉ－Ｃｕ－Ｍｇ系）等の鋳物用アルミニウム合金；ＡＤＣ１（Ａｌ－Ｓｉ系）、ＡＤＣ３（Ａｌ－Ｓｉ－Ｍｇ系）、ＡＤＣ５（Ａｌ－Ｍｇ系）、ＡＤＣ６（Ａｌ－Ｍｇ－Ｍｎ系）、ＡＤＣ１０（Ａｌ－Ｓｉ－Ｃｕ系）、ＡＤＣ１２（Ａｌ－Ｓｉ－Ｃｕ系）、ＡＤＣ１４（Ａｌ－Ｓｉ－Ｃｕ－Ｍｇ系）等のダイキャスト用アルミニウム合金などを用いることができる。また、これらを熱処理（時効処理）等して調質したものを用いることができる。 (Aluminum, aluminum alloy)
Aluminum has a small specific gravity of about 2.7 Mg / m 3 and is suitable as a lightweight material. However, from the viewpoint of strength, it is preferable to use an aluminum alloy as the back plate. Aluminum alloys include 2XXX (Al-Cu), 3XXX (Al-Mn), 4XXX (Al-Si), 5XXX (Al-Mg), and 6XXX (Al-Mg-Si). ), 7XXX (Al-Zn-based) and other aluminum alloys for spreading; AC1C (Al-Cu-based), AC1B (Al-Cu-based), AC2A (Al-Cu-Si-based), AC2B (Al-Cu-) Si-based), AC3A (Al-Si-based), AC4A, AC4C (Al-Si-Mg-based), AC4B (Al-Si-Cu-based), AC4D (Al-Si-Cu-Mg-based), AC5A (Al- Cu-Ni-Mg), AC7A (Al-Mg), AC8A (Al-Si-Cu-Ni-Mg), AC8B (Al-Si-Cu-Ni-Mg), AC9A (Al-Si-) Cu-Mg type , AC9B (Al-Si-Cu-Mg) and other casting aluminum alloys; ADC1 (Al-Si), ADC3 (Al-Si-Mg), ADC5 (Al-Mg), ADC6 (Al-Mg) -Mn-based), die-cast aluminum alloys such as ADC10 (Al-Si-Cu-based), ADC12 (Al-Si-Cu-based), and ADC14 (Al-Si-Cu-Mg-based). In addition, those obtained by tempering these materials by heat treatment (aging treatment) or the like can be used.
（アルミニウム複合材）
　アルミニウム又は上記のアルミニウム合金中にセラミックス粒子を分散させたアルミニウム複合材（セラミックス粒子強化アルミニウム基複合材料）は、アルミニウム合金に比してヤング率が高くなるため、バックプレートとして用いると、ブレーキパッドの剛性を高くすることができ、好適である。分散強化するセラミックス粒子としては、Ａｌ２Ｏ３、ＴｉＯ２、ＳｉＯ２、ＺｒＯ２等の酸化物系セラミックス、ＳｉＣ、ＴｉＣ等の炭化物系セラミックス、ＴｉＮ等の窒化物系セラミックスを用いることができる。 (Aluminum composite)
Aluminum composite materials (ceramic particle reinforced aluminum-based composite materials) in which ceramic particles are dispersed in aluminum or the above aluminum alloy have a higher Young's modulus than aluminum alloys. The rigidity can be increased, which is preferable. As the ceramic particles to be dispersion strengthened, oxide ceramics such as Al 2 O 3 , TiO 2 , SiO 2 , ZrO 2 , carbide ceramics such as SiC and TiC, and nitride ceramics such as TiN can be used.
（マグネシウム、マグネシウム合金）
　マグネシウムは比重が１．７４Ｍｇ／ｍ３と小さいため、軽量化素材として好適であるが、強度の観点から、バックプレートとしてはマグネシウム合金を用いることが好ましい。マグネシウム合金としては、Ｍ１（Ｍｇ－Ｍｎ合金）、ＡＺ６１、ＡＺ９１等のＡＺ系（Ｍｇ－Ａｌ－Ｚｎ合金）、ＺＫ５１、ＺＫ６０等のＺＫ系（Ｍｇ－Ｚｎ－Ｚｒ合金）、ＺＨ６２等のＺＨ系（Ｍｇ－Ｚｎ－Ｚｒ合金）、ＥＫ３０等のＥＫ系（Ｍｇ－希土類元素合金）、ＨＫ３１等のＨＫ系（Ｍｇ－Ｔｈ系合金）、Ｋ１（Ｍｇ－Ｚｒ合金）等の各種鋳造用マグネシウム合金及び加工用マグネシウム合金を用いることができる。また、カルシウムを数％添加した難燃性マグネシウム合金を用いることができる。 (Magnesium, magnesium alloy)
Since magnesium has a small specific gravity of 1.74 Mg / m 3 , it is suitable as a lightweight material, but from the viewpoint of strength, it is preferable to use a magnesium alloy as the back plate. Examples of magnesium alloys include M1 (Mg-Mn alloy), AZ-based (Mg-Al-Zn alloy) such as AZ61 and AZ91, ZK-based (Mg-Zn-Zr alloy) such as ZK51 and ZK60, and ZH-based such as ZH62. (Mg-Zn-Zr alloy), various magnesium alloys for casting such as EK-based (Mg-rare earth element alloy) such as EK30, HK-based (Mg-Th-based alloy) such as HK31, and K1 (Mg-Zr alloy); A magnesium alloy for processing can be used. In addition, a flame-retardant magnesium alloy to which calcium is added by several% can be used.
（マグネシウム複合材）
　マグネシウム又は上記のマグネシウム合金中にセラミックス粒子を分散させたアルミニウム複合材（セラミックス粒子強化マグネシウム基複合材料）は、マグネシウム合金に比してヤング率が高くなるため、バックプレートとして用いると、ブレーキパッドの剛性を高くすることができ、好適である。分散強化するセラミックス粒子としては、Ａｌ２Ｏ３、ＴｉＯ２、ＳｉＯ２、ＺｒＯ２等の酸化物系セラミックス、ＳｉＣ、ＴｉＣ等の炭化物系セラミックス、ＴｉＮ等の窒化物系セラミックスを用いることができる。 (Magnesium composite)
An aluminum composite material (ceramic particle reinforced magnesium-based composite material) in which ceramic particles are dispersed in magnesium or the above magnesium alloy has a higher Young's modulus than a magnesium alloy. The rigidity can be increased, which is preferable. As the ceramic particles to be dispersion strengthened, oxide ceramics such as Al 2 O 3 , TiO 2 , SiO 2 , ZrO 2 , carbide ceramics such as SiC and TiC, and nitride ceramics such as TiN can be used.
　なお、バックプレートの厚み方向の熱伝導率を高くすることで、繰り返し制動を行い摩擦熱でブレーキ温度が上昇したときに、バックプレート内の温度分布を均一にすることができ、局所的な温度上昇を防ぎ、樹脂の熱分解及び強度低下に伴うクラック、割れを防止し易い傾向にある。この観点から、バックプレートの厚み方向の熱伝導率は、０．３０Ｗ／ｍ・Ｋ以上であることが好ましく、０．３５Ｗ／ｍ・Ｋ以上であることがより好ましく、１．０Ｗ／ｍ・Ｋ以上であることがさらに好ましい。バックプレートの厚み方向の熱伝導率の上限値に特に制限はないが、４００Ｗ／ｍ・Ｋ以下であってもよいし、２５０Ｗ／ｍ・Ｋ以下であってもよいし、１５０Ｗ／ｍ・Ｋ以下であってもよい。 In addition, by increasing the thermal conductivity in the thickness direction of the back plate, when braking is repeatedly performed and the brake temperature increases due to frictional heat, the temperature distribution in the back plate can be made uniform, and the local temperature can be reduced. It tends to prevent the resin from rising, and to easily prevent cracks and cracks due to thermal decomposition and strength reduction of the resin. From this viewpoint, the thermal conductivity in the thickness direction of the back plate is preferably 0.30 W / m · K or more, more preferably 0.35 W / m · K or more, and 1.0 W / m · K or more. More preferably, it is K or more. The upper limit of the thermal conductivity in the thickness direction of the back plate is not particularly limited, but may be 400 W / m · K or less, 250 W / m · K or less, or 150 W / m · K. It may be as follows.
　次に、下張り材３に用いる材料（以下、下張り材用摩擦材組成物と称する。）について詳述する。本発明は、下張り材用摩擦材組成物を成形してなる下張り材も提供するものであり、該「下張り材用摩擦材組成物」が含有し得る各成分は、「下張り材」が含有し得る成分ということになる。つまり、後述する「下張り材用摩擦材組成物」中の各成分に関する説明は、「下張り材」中の各成分に関する説明として読み替えることができる。 Next, the material used for the underlining material 3 (hereinafter, referred to as a friction material composition for underlining material) will be described in detail. The present invention also provides an underlining material formed by molding the underlining material friction material composition, and each component that can be contained in the “underlining material friction material composition” is included in the “underlining material”. It is a component to be obtained. In other words, the description about each component in the “friction material composition for underlining material” described below can be read as the description about each component in the “underlining material”.
［下張り材用摩擦材組成物］
　本発明で用いる下張り材用摩擦材組成物は、空隙を有する粒子を含有する下張り材用摩擦材組成物である。
　本発明で用いる下張り材用摩擦材組成物の好ましい態様は、前記空隙を有する粒子と共に、さらに有機充填材、無機充填材、有機繊維及び結合材からなる群から選択される少なくとも１種（但し、該有機充填材及び該無機充填材からは、前記空隙を有する粒子は除かれる。）を含有する下張り材用摩擦材組成物であり、より好ましい態様は、前記空隙を有する粒子と共に、さらに有機充填材、無機充填材、有機繊維及び結合材（但し、該有機充填材及び該無機充填材からは、前記空隙を有する粒子は除かれる。）を含有する下張り材用摩擦材組成物である。 [Friction material composition for underlay material]
The friction material composition for underlining material used in the present invention is a friction material composition for underlining material containing particles having voids.
A preferred embodiment of the friction material composition for an underlining material used in the present invention is, together with the particles having voids, at least one selected from the group consisting of an organic filler, an inorganic filler, an organic fiber, and a binder (however, The particles having the voids are excluded from the organic filler and the inorganic filler.) A more preferred embodiment is a friction material composition for an underlaying material, which further comprises an organic filler together with the particles having the voids. A friction material composition for an underlining material comprising a material, an inorganic filler, an organic fiber, and a binder (however, the particles having the voids are excluded from the organic filler and the inorganic filler).
　ところで、摩擦材の強度のためには銅又は銅合金を含有する摩擦材が有利であることが知られているが、銅又は銅合金を含有する摩擦材は制動により発生する摩耗粉に銅を多量に含むため、それが河川、湖及び海洋等の汚染の原因となることが示唆されており、米国、特にカリフォルニア、ワシントンを中心として、摩擦材（上張り材）における銅成分の使用量を制限する法律が施行されている。そのため、米国をはじめ、諸外国にて使用し得る摩擦材とするには、銅を含有しないか、又は銅の含有量を大幅に低減する必要があり、銅を含有する摩擦材は、現在では商業的価値が乏しくなっている。そのため、本発明の下張り材用摩擦材組成物においても銅を含有しないことが好ましいが、銅を含む場合には、下張り材用摩擦材組成物における銅の含有率を銅元素として０．５質量％未満とすることにより、環境中に摩耗粉として放出されても、河川等の汚染を引き起こさないものとすることができる。なお、銅の含有率は、繊維状及び粉末状等の銅、銅合金及び銅化合物に含まれる銅元素（Ｃｕ）の、下張り材用摩擦材組成物全体における含有率を示す。下張り材用摩擦材組成物における銅の含有率は、銅元素として０．２質量％以下であることがより好ましく、０．０５質量％以下であることがさらに好ましい。
　以上より、本発明の下張り材用摩擦材組成物においても、銅を含まないか、又は含んでいてもその含有率が、銅元素として０．５質量％未満であることが好ましい。 By the way, it is known that a friction material containing copper or a copper alloy is advantageous for the strength of the friction material.However, a friction material containing copper or a copper alloy contains copper as wear powder generated by braking. It has been suggested that it causes pollution of rivers, lakes and oceans due to its large amount, and the use of copper components in friction materials (overlaying materials) has been reduced mainly in the United States, especially California and Washington. Restricting laws are in place. Therefore, in order to be a friction material that can be used in other countries including the United States, it is necessary to not contain copper or to significantly reduce the content of copper. Commercial value is poor. Therefore, it is preferable that the friction material composition for underlining material of the present invention does not contain copper, but when copper is contained, the content of copper in the friction material composition for underlining material is 0.5 mass% as a copper element. By setting it to less than%, even if it is released as abrasion powder into the environment, it is possible to prevent pollution of rivers and the like. The copper content indicates the content of copper element (Cu) contained in fibrous and powdery copper, copper alloys and copper compounds in the entire friction material composition for underlining materials. The content of copper in the friction material composition for underlaying material is more preferably 0.2% by mass or less as a copper element, and further preferably 0.05% by mass or less.
As described above, in the friction material composition for underlining material of the present invention, it is preferable that copper is not contained, or even if copper is contained, its content is less than 0.5% by mass as a copper element.
　また、下張り材から鉄繊維等の鉄系金属を除くと、バックプレートとの接着界面での発錆による耐久性低下等の問題が生じなくなる傾向にある。そのため、金属繊維を用いず、その代わりに無機繊維を用いる試みもなされたが、その場合、金属繊維のような靭性が得られず、常温又は高温でのせん断強度が低下するという問題、及び耐クラック性が低下する等の問題が新たに発生し得ることが判明した。ここで、鉄系金属とは、鉄を主成分とする金属であって、一般的な鉄鋼を指し、鉄の含有率は、鉄、鉄合金及び鉄化合物に含まれる鉄元素（Ｆｅ）の、下張り材用摩擦材組成物全体における含有率を示す。
　そこで、発錆による耐久性低下等を避ける観点から、本発明の下張り材用摩擦材組成物においては鉄系金属を含有しないことが好ましいが、鉄系金属を含む場合であっても、下張り材用摩擦材組成物における鉄系金属の含有率を鉄元素として０．５質量％未満とすることにより、耐錆性を良好なものとすることができ、バックプレートとの接着界面での発錆による耐久性低下を抑制できる。本発明においては、鉄系金属の含有率を前記範囲に抑えても十分な靭性を有し、常温又は高温でのせん断強度も高く、耐クラック性も良好であり、且つ耐摩耗性も良好である。下張り材用摩擦材組成物における鉄系金属の含有率は、鉄元素として０．２質量％以下であることがより好ましく、０．０５質量％以下であることがさらに好ましい。
　以上より、本発明の下張り材用摩擦材組成物においても、鉄系金属を含まないか、又は含んでいてもその含有量が、鉄元素として０．５質量％未満であることが好ましい。 In addition, when iron-based metals such as iron fibers are removed from the underlaying material, there is a tendency that problems such as deterioration of durability due to rust at the bonding interface with the back plate do not occur. For this reason, attempts have been made to use inorganic fibers instead of metal fibers.However, in such a case, the toughness of metal fibers cannot be obtained, and the problem that the shear strength at room temperature or high temperature is reduced, and the problem of resistance It has been found that problems such as a decrease in cracking properties can newly occur. Here, the iron-based metal is a metal containing iron as a main component and refers to general iron and steel. The iron content is determined based on the iron element (Fe) contained in iron, iron alloys, and iron compounds. It shows the content in the entire friction material composition for underlining materials.
Therefore, from the viewpoint of avoiding a decrease in durability due to rust, it is preferable that the friction material composition for an underlining material of the present invention does not contain an iron-based metal. By making the content of the iron-based metal in the friction material composition for iron less than 0.5% by mass as an iron element, rust resistance can be improved, and rusting occurs at the bonding interface with the back plate. Can suppress the reduction in durability. In the present invention, even if the content of the iron-based metal is suppressed to the above range, it has sufficient toughness, high shear strength at room temperature or high temperature, good crack resistance, and good wear resistance. is there. The content of the iron-based metal in the friction material composition for underlaying material is more preferably 0.2% by mass or less as an iron element, and further preferably 0.05% by mass or less.
As described above, in the friction material composition for underlining material of the present invention, it is preferable that the iron-based metal is not contained or the content thereof is less than 0.5% by mass as an iron element.
　なお、本発明の下張り材用摩擦材組成物は、ＮＡＯ（Non-Asbestos-Organic）材に分類されるものであり、いわゆるノンアスベスト摩擦材組成物（アスベストを含有しない摩擦材組成物、又は含有する場合であってもアスベストの含有量が極微量の摩擦材組成物）である。本発明の下張り材用摩擦材組成物中、アスベストの含有量は好ましくは０．２質量％以下であり、より好ましくは実質的に０質量％である。 The friction material composition for underlining material of the present invention is classified as a non-asbestos-organic (NAO) material, and is a so-called non-asbestos friction material composition (a friction material composition containing no asbestos or containing asbestos). Even when the friction material composition is used, the asbestos content is a very small amount. In the friction material composition for underlining material of the present invention, the content of asbestos is preferably 0.2% by mass or less, more preferably substantially 0% by mass.
　以下、本発明の下張り材用摩擦材組成物の各成分について順に説明する。
（空隙を有する粒子）
　本発明の下張り材用摩擦材組成物は、前述のとおり、空隙を有する粒子を含有する。空隙を有する粒子は、１種を単独で使用してもよいし、２種以上を併用してもよい。空隙を有する粒子を含有することで繰り返し制動後のバックプレートの耐久性が向上する。下張り材の内部に亀裂を生じさせるなどの手段によって下張り材内に空隙を形成することもできるが、当該方法では下張り材の強度が低下するため、強度と共に繰り返し制動後のバックプレートの耐久性を向上させるためには、下張り材に空隙を有する粒子を含有させる必要がある。
　空隙を有する粒子は、例えば、フライアッシュバルーン、シラスバルーン、珪藻土、中空ガラス粒子、ケイ酸カルシウム粒子、中空シリカ粒子、アルミナバルーン、ジルコニアバルーン、γ－アルミナ粒子及びフェノール樹脂バルーンからなる群から選択される少なくとも１種であることが好ましい。
　空隙を有する粒子は、一次粒子内に空隙を有していてもよいし、たとえ一次粒子内に空隙を有していなくても、一次粒子が凝集して形成された二次粒子内に空隙を有するものであってもよい。なお、二次粒子とは、例えば数個から数十個の一次粒子の表面が接触し合い、擬似的な粒子を構成しているものを言う。 Hereinafter, each component of the friction material composition for underlining material of the present invention will be described in order.
(Void particles)
As described above, the friction material composition for underlining material of the present invention contains voided particles. As the particles having voids, one type may be used alone, or two or more types may be used in combination. By containing particles having voids, the durability of the back plate after repeated braking is improved. Although it is possible to form a gap in the underlaying material by means such as generating a crack in the underlaying material, the strength of the underlining material is reduced in this method, so that together with the strength, the durability of the back plate after repeated braking is reduced. In order to improve the quality, it is necessary to make the underlay material contain particles having voids.
The particles having voids are selected from the group consisting of, for example, fly ash balloons, shirasu balloons, diatomaceous earth, hollow glass particles, calcium silicate particles, hollow silica particles, alumina balloons, zirconia balloons, γ-alumina particles, and phenol resin balloons. Preferably, at least one of them is used.
The particles having voids may have voids in the primary particles, or even if they do not have voids in the primary particles, voids may be formed in the secondary particles formed by aggregation of the primary particles. You may have. Note that the secondary particles refer to, for example, particles in which several to several tens of primary particles are in contact with each other to form pseudo particles.
　空隙を有する粒子のうち、一次粒子内に空隙を有しているものとしては、例えば、中空ガラス粒子、中空シリカ粒子、フライアッシュバルーン、シラスバルーン、アルミナバルーン、ジルコニアバルーン、フェノール樹脂バルーン等が挙げられる。一次粒子内に空隙を有しているものとしては、空隙が物体内部に孤立している閉気孔のもの、空隙が外部と接触している開気孔のもの、のどちらも使用することができる。これらの中でも、中空ガラス粒子、ケイ酸カルシウム粒子が好ましく、下張り材の強度の観点及び繰り返し制動後のバックプレートの耐久性の観点から、中空ガラス粒子がより好ましい。これらの一次平均粒子径は特に制限されるものではないが、好ましくは５～４００μｍ、より好ましくは１０～３００μｍ、さらに好ましくは１０～１５０μｍ、特に好ましくは１０～１００μｍ、最も好ましくは１５～６０μｍである。
　空隙を有する粒子のうち、二次粒子内に空隙を有するものとしては、例えば、ケイ酸カルシウム粒子、γ－アルミナ粒子、珪藻土等が挙げられる。これらの中でも、ケイ酸カルシウム粒子、γ－アルミナ粒子が好ましい。これらの二次平均粒子径は特に制限されるものではないが、好ましくは５～４００μｍ、より好ましくは１０～３００μｍ、さらに好ましくは３０～２５０μｍである。ケイ酸カルシウム粒子の場合には、二次平均粒子径は１０～１５０μｍであってもよいし、３０～１００μｍであってもよい。また、γ－アルミナ粒子の場合には、二次平均粒子径は１００～４００μｍであってもよいし、１５０～３００μｍであってもよいし、１５０～２５０μｍであってもよい。
　以上の中でも、空隙を有する粒子としては、中空ガラス粒子、ケイ酸カルシウム粒子及びγ－アルミナ粒子からなる群から選択される少なくとも１種が好ましく、下張り材の強度及び製造コストの観点から、中空ガラス粒子及びケイ酸カルシウム粒子からなる群から選択される少なくとも１種がより好ましく、中空ガラス粒子がさらに好ましい。
　前記中空ガラス粒子としては、中空ケイ酸ガラス粒子、中空アルミケイ酸ガラス粒子、中空ホウケイ酸ガラス粒子等が挙げられる。 Among the particles having voids, those having voids in the primary particles include, for example, hollow glass particles, hollow silica particles, fly ash balloons, shirasu balloons, alumina balloons, zirconia balloons, phenol resin balloons, and the like. Can be As the one having a void in the primary particle, either a closed pore in which the void is isolated inside the object or an open pore in which the void is in contact with the outside can be used. Among these, hollow glass particles and calcium silicate particles are preferable, and hollow glass particles are more preferable from the viewpoint of the strength of the underlay material and the durability of the back plate after repeated braking. The primary average particle size is not particularly limited, but is preferably 5 to 400 μm, more preferably 10 to 300 μm, further preferably 10 to 150 μm, particularly preferably 10 to 100 μm, and most preferably 15 to 60 μm. is there.
Among the particles having voids, those having voids in the secondary particles include, for example, calcium silicate particles, γ-alumina particles, and diatomaceous earth. Among these, calcium silicate particles and γ-alumina particles are preferred. The secondary average particle size is not particularly limited, but is preferably 5 to 400 μm, more preferably 10 to 300 μm, and further preferably 30 to 250 μm. In the case of calcium silicate particles, the secondary average particle size may be from 10 to 150 μm or from 30 to 100 μm. In the case of γ-alumina particles, the secondary average particle diameter may be 100 to 400 μm, 150 to 300 μm, or 150 to 250 μm.
Among the above, the particles having voids are preferably at least one selected from the group consisting of hollow glass particles, calcium silicate particles, and γ-alumina particles. At least one selected from the group consisting of particles and calcium silicate particles is more preferable, and hollow glass particles are more preferable.
Examples of the hollow glass particles include hollow silicate glass particles, hollow aluminum silicate glass particles, and hollow borosilicate glass particles.
　空隙を有する粒子の空隙率に特に制限はないが、繰り返し制動後のバックプレートの耐久性の観点から、好ましくは３０体積％以上、より好ましくは５０体積％以上、さらに好ましくは６５体積％以上、特に好ましくは７０体積％以上である。
　下張り材用摩擦材組成物において、空隙を有する粒子の含有量は、好ましくは０．１～３０質量％、より好ましくは０．５～２５質量％、さらに好ましくは１～１５質量％、特に好ましくは１～８質量％である。 The porosity of the particles having voids is not particularly limited, but from the viewpoint of the durability of the back plate after repeated braking, is preferably 30% by volume or more, more preferably 50% by volume or more, and still more preferably 65% by volume or more. It is particularly preferably at least 70% by volume.
In the friction material composition for an underlaying material, the content of particles having voids is preferably 0.1 to 30% by mass, more preferably 0.5 to 25% by mass, still more preferably 1 to 15% by mass, and particularly preferably. Is 1 to 8% by mass.
（有機充填材）
　有機充填材は、制振性及び耐摩耗性等を向上させるための摩擦調整剤としての機能を発現し得るものである。ここで、本発明において、該有機充填材は繊維形状のもの（例えば後述の有機繊維）を含まない。有機充填材は、１種を単独で使用してもよいし、２種以上を併用してもよい。
　前記有機充填材としては、摩擦材組成物に一般的に用いられる有機充填材を使用することができ、例えば、カシューパーティクル、ゴム、メラミンダスト等が挙げられる。これらの中でも、摩擦係数の安定性及び耐摩耗性を良好とする観点並びに鳴きを抑制する観点から、カシューパーティクル、ゴムが好ましい。
　また、有機充填材としては、カシューパーティクルとゴムとを併用してもよいし、カシューパーティクルをゴムで被覆したものを用いてもよい。 (Organic filler)
The organic filler can exhibit a function as a friction modifier for improving the vibration damping property and the wear resistance. Here, in the present invention, the organic filler does not include a fibrous material (for example, an organic fiber described later). One kind of the organic filler may be used alone, or two or more kinds may be used in combination.
As the organic filler, an organic filler generally used in a friction material composition can be used, and examples thereof include cashew particles, rubber, and melamine dust. Among these, cashew particles and rubber are preferable from the viewpoint of improving the stability of the coefficient of friction and the abrasion resistance and suppressing the squeal.
Further, as the organic filler, cashew particles and rubber may be used in combination, or cashew particles coated with rubber may be used.
　前記カシューパーティクルは、カシューナッツシェルオイルを硬化させたものを粉砕して得られ、一般的に、カシューダストと称されることもある。
　カシューパーティクルは、一般的に、硬化反応に使用する硬化剤の種類に応じて、茶系、茶黒系、黒系等に分類される。カシューパーティクルは、分子量等を調整することで、耐熱性及び音振性、さらに相手材であるロータへの皮膜形成性等を制御し易くすることが可能である。
　カシューパーティクルの平均粒子径は、分散性の観点から、８５０μｍ以下であることが好ましく、７５０μｍ以下であることがより好ましく、６００μｍ以下であることがさらに好ましい。カシューパーティクルの平均粒子径の下限値に特に制限はなく、２００μｍ以上であってもよく、３００μｍ以上であってもよく、４００μｍ以上であってもよい。なお、本明細書において、平均粒子径は、レーザー回折粒度分布測定の方法を用いて測定したｄ５０の値（体積分布のメジアン径、累積中央値）を意味し、以下同様である。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）で測定することができる。
　カシューパーティクルは、１種を単独で使用してもよいし、２種以上を併用してもよい。
　本発明の下張り材用摩擦材組成物がカシューパーティクルを含有する場合、その含有量は、好ましくは０．５～１５質量％、より好ましくは１～１０質量％、さらに好ましくは２～５質量％である。０．５質量％以上とすることで、摩擦材とディスクロータ表面の撥水性が改善される傾向にあり、さらに摩擦材に適度な柔軟性を付与することができるため、音振性を改善できる傾向にある。一方、１５質量％以下とすることで、耐熱性および耐クラック性の低下を防げる傾向にある。 The cashew particles are obtained by pulverizing hardened cashew nut shell oil and may be generally referred to as cashew dust.
Cashew particles are generally classified into brown, brown-black, black, and the like, depending on the type of curing agent used in the curing reaction. By adjusting the molecular weight and the like of the cashew particles, it is possible to easily control the heat resistance, the sound and vibration properties, and the film forming property on the rotor as the mating material.
The average particle size of the cashew particles is preferably 850 μm or less, more preferably 750 μm or less, and even more preferably 600 μm or less, from the viewpoint of dispersibility. The lower limit of the average particle size of the cashew particles is not particularly limited, and may be 200 μm or more, 300 μm or more, or 400 μm or more. In the present specification, the average particle diameter means a value of d50 (median diameter of volume distribution, cumulative median value) measured using a laser diffraction particle size distribution measuring method, and the same applies hereinafter. For example, it can be measured with a laser diffraction / scattering type particle size distribution analyzer, trade name: LA.920 (manufactured by Horiba, Ltd.).
One type of cashew particles may be used alone, or two or more types may be used in combination.
When the friction material composition for underlining material of the present invention contains cashew particles, the content is preferably 0.5 to 15% by mass, more preferably 1 to 10% by mass, and still more preferably 2 to 5% by mass. It is. When the content is 0.5% by mass or more, the water repellency of the friction material and the disk rotor surface tends to be improved, and the friction material can be given appropriate flexibility, so that sound vibration can be improved. There is a tendency. On the other hand, by setting the content to 15% by mass or less, a decrease in heat resistance and crack resistance tends to be prevented.
　前記ゴムとしては摩擦材組成物に通常用いられるゴムが挙げられ、例えば天然ゴム、合成ゴムが挙げられ、合成ゴムとしては、例えば、アクリロニトリル－ブタジエンゴム（ＮＢＲ）、アクリルゴム、イソプレンゴム、ポリブタジエンゴム（ＢＲ）、スチレンブタジエンゴム（ＳＢＲ）、シリコーンゴム、タイヤトレッドゴムの粉砕粉等が挙げられる。これらの中でも、耐熱性、柔軟性及び製造コストのバランスの観点から、アクリロニトリル－ブタジエンゴム（ＮＢＲ）、タイヤトレッドゴムの粉砕粉が好ましい。
　本発明の下張り材用摩擦材組成物がゴムを含有する場合、その含有量は、下張り材用摩擦材組成物中、好ましくは１～３０質量％、より好ましくは２～１５質量％、さらに好ましくは２～６質量％である。前記ゴムの含有量を上記範囲とすることで、下張り材の弾性率が高くなること、及び鳴き等の制振性が悪化することを避けることができる傾向にあり、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傾向にある。 Examples of the rubber include rubbers commonly used in friction material compositions, such as natural rubber and synthetic rubber. Examples of the synthetic rubber include acrylonitrile-butadiene rubber (NBR), acrylic rubber, isoprene rubber, and polybutadiene rubber. (BR), styrene-butadiene rubber (SBR), silicone rubber, pulverized powder of tire tread rubber, and the like. Among them, acrylonitrile-butadiene rubber (NBR) and pulverized powder of tire tread rubber are preferable from the viewpoint of balance between heat resistance, flexibility and production cost.
When the friction material composition for underlining material of the present invention contains rubber, its content is preferably 1 to 30% by mass, more preferably 2 to 15% by mass, and still more preferably, in the friction material composition for underlining material. Is from 2 to 6% by mass. By setting the content of the rubber in the above range, the elastic modulus of the underlining material is increased, and there is a tendency that it is possible to avoid deterioration of vibration damping properties such as squealing, There is a tendency that a decrease in strength due to heat history can be avoided.
　下張り材用摩擦材組成物が有機充填材を含有する場合、その含有量は、下張り材用摩擦材組成物中、好ましくは１～２０質量％、より好ましくは２～１０質量％、さらに好ましくは３～１０質量％である。有機充填材の合計含有量を上記範囲とすることで、下張り材の弾性率が高くなること、並びに鳴き等の制振性の悪化及び耐摩耗性の悪化を避けることができる傾向にあり、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傾向にある。 When the friction material composition for underlining material contains an organic filler, its content is preferably 1 to 20% by mass, more preferably 2 to 10% by mass, and still more preferably, in the friction material composition for underlining material. It is 3 to 10% by mass. By setting the total content of the organic filler in the above range, the elastic modulus of the underlay material is increased, and there is a tendency that deterioration of vibration damping properties such as squeal and deterioration of wear resistance can be avoided, and In addition, there is a tendency that deterioration in heat resistance and reduction in strength due to heat history can be avoided.
（無機充填材）
　無機充填材は、下張り材の耐熱性、耐摩耗性、摩擦係数の安定性等の悪化を避けるための摩擦調整材としての機能を発現し得るものである。ここで、本発明においては、該無機充填材は繊維形状のもの（例えば後述の無機繊維）を含まない。無機充填材は、１種を単独で使用してもよいし、２種以上を併用してもよい。
　該無機充填材としては特に制限はなく、下張り材に通常用いられる無機充填材でよい。無機充填材としては、例えば、三硫化アンチモン、硫化スズ、二硫化モリブデン、硫化ビスマス、硫化亜鉛等の金属硫化物；チタン酸カリウム、チタン酸リチウムカリウム、チタン酸ナトリウム、チタン酸マグネシウムカリウム等のチタン酸塩；マイカ、黒鉛、コークス、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、ドロマイト、コークス、マイカ、バーミキュライト、硫酸カルシウム、粒状チタン酸カリウム、板状チタン酸カリウム、タルク、クレー、ゼオライト、クロマイト、酸化ジルコニウム、酸化チタン、酸化マグネシウム、四酸化三鉄、酸化亜鉛、γ－アルミナ；鉄粉末、鋳鉄粉末、アルミニウム粉末、ニッケル粉末、スズ粉末、亜鉛粉末、及び前記金属のうちの少なくとも１つの金属を含有する合金粉末等の金属粉末などが挙げられるが、銅及び鉄系金属を含有しないものが好ましい。これらの中でも、金属硫化物、チタン酸塩、マイカ、黒鉛、水酸化カルシウム及び硫酸バリウムからなる群から選択される少なくとも１種であってもよく、硫酸バリウムが好ましい。 (Inorganic filler)
The inorganic filler can exhibit a function as a friction adjusting material for avoiding deterioration of the heat resistance, abrasion resistance, stability of friction coefficient and the like of the underlining material. Here, in the present invention, the inorganic filler does not include a fibrous material (for example, an inorganic fiber described later). As the inorganic filler, one type may be used alone, or two or more types may be used in combination.
The inorganic filler is not particularly limited, and may be an inorganic filler usually used for an underlay material. Examples of the inorganic filler include metal sulfides such as antimony trisulfide, tin sulfide, molybdenum disulfide, bismuth sulfide, and zinc sulfide; and titanium such as potassium titanate, lithium potassium titanate, sodium titanate, and potassium magnesium titanate. Acid salts: mica, graphite, coke, calcium hydroxide, calcium oxide, sodium carbonate, calcium carbonate, magnesium carbonate, barium sulfate, dolomite, coke, mica, vermiculite, calcium sulfate, granular potassium titanate, plate-like potassium titanate, Talc, clay, zeolite, chromite, zirconium oxide, titanium oxide, magnesium oxide, triiron tetroxide, zinc oxide, γ-alumina; iron powder, cast iron powder, aluminum powder, nickel powder, tin powder, zinc powder, and the above metals Small of A metal powder of an alloy powder and the like containing Kutomo one metals, but preferably containing no copper and ferrous metal. Among these, at least one selected from the group consisting of metal sulfides, titanates, mica, graphite, calcium hydroxide, and barium sulfate may be used, and barium sulfate is preferred.
　前記黒鉛としては、特に制限されるものではなく、公知の黒鉛、つまり、天然黒鉛、人造黒鉛のいずれも使用することができるが、下張り材の熱伝導率が上昇するのを抑制するため、その含有量は、下張り材用摩擦材組成物中、好ましくは５質量％以下、より好ましくは３質量％以下、さらに好ましくは２質量％以下であり、特に好ましくは実質的に０質量％である。 The graphite is not particularly limited, and any known graphite, that is, natural graphite or artificial graphite can be used.However, in order to suppress an increase in the thermal conductivity of the underlining material, The content is preferably 5% by mass or less, more preferably 3% by mass or less, further preferably 2% by mass or less, and particularly preferably substantially 0% by mass, in the friction material composition for underlining material.
　本発明の下張り材用摩擦材組成物が硫酸バリウムを含有する場合、その含有量は特に制限されるものではなく、他の成分の配合量と合わせて下張り材用摩擦材組成物の総量を１００質量部に調整するための「残部」に相当する。 When the friction material composition for underlining material of the present invention contains barium sulfate, the content thereof is not particularly limited, and the total amount of the friction material composition for underlining material is 100 in accordance with the blending amount of other components. It corresponds to the "remainder" for adjusting to parts by mass.
　本発明の下張り材用摩擦材組成物が無機充填材を含有する場合、その含有量は、下張り材用摩擦材組成物中、好ましくは２０～７５質量％、より好ましくは３０～７０質量％、さらに好ましくは４０～６５質量％、特に好ましくは４０～６０質量％である。無機充填材の含有量を上記範囲とすることで、耐熱性の悪化を避け易い。無機充填材の含有量の上限値は、５５質量％以下であってもよい。 When the friction material composition for underlining material of the present invention contains an inorganic filler, the content is preferably 20 to 75% by mass, more preferably 30 to 70% by mass in the friction material composition for underlining material. More preferably, it is 40 to 65% by mass, particularly preferably 40 to 60% by mass. By setting the content of the inorganic filler in the above range, deterioration of heat resistance can be easily avoided. The upper limit of the content of the inorganic filler may be 55% by mass or less.
（繊維基材；有機繊維及び無機繊維）
　繊維基材は、下張り材において補強作用を示すものである。本発明の下張り材用摩擦材組成物は、繊維基材として、有機繊維及び無機繊維を含有することが好ましい。繊維基材は、１種を単独で使用してもよいし、２種以上を併用してもよい。無機繊維は、下張り材の機械的強度及び耐摩耗性を向上する効果を発現し得るものである。有機繊維とは、有機物を主成分とする繊維状の材料である。 (Fiber base material: organic fiber and inorganic fiber)
The fibrous base material has a reinforcing effect on the underlay material. The friction material composition for underlining material of the present invention preferably contains an organic fiber and an inorganic fiber as a fiber base material. One type of fiber base material may be used alone, or two or more types may be used in combination. Inorganic fibers can exhibit the effect of improving the mechanical strength and wear resistance of the underlay material. The organic fiber is a fibrous material containing an organic substance as a main component.
－有機繊維－
　前記有機繊維としては、麻、木綿、アラミド繊維、セルロース繊維、アクリル繊維、フェノール樹脂繊維（架橋構造を有する）等が挙げられる。
　有機繊維は、１種を単独で使用してもよいし、２種以上を併用してもよい。
　有機繊維としては、耐熱性の観点から、アラミド繊維が好ましい。また、下張り材の強度向上の観点から、有機繊維として、フィブリル化有機繊維を含有することが好ましく、フィブリル化アラミド繊維を含有することがより好ましい。フィブリル化有機繊維とは、分繊化し、毛羽立ちをもった有機繊維であり、商業的に入手することができる。言うまでもなく、本発明の下張り材用摩擦材組成物は、フィブリル化有機繊維と共にその他の有機繊維を含有していてもよい。
　本発明の下張り材用摩擦材組成物が有機繊維（例えばフィブリル化有機繊維）を含有する場合、その含有量は、下張り材用摩擦材組成物中、１～８質量％であることが好ましく、２～７質量％であることがより好ましく、３～７質量％であることがさらに好ましい。１質量％以上であれば、良好なせん断強度、耐クラック性及び耐摩耗性が発現する傾向にあり、８質量％以下であれば、下張り材用摩擦材組成物中の有機繊維（フィブリル化有機繊維）と他材料の偏在によるせん断強度及び耐クラック性の悪化を効果的に抑制することができる。 -Organic fiber-
Examples of the organic fiber include hemp, cotton, aramid fiber, cellulose fiber, acrylic fiber, and phenol resin fiber (having a crosslinked structure).
One type of organic fiber may be used alone, or two or more types may be used in combination.
As the organic fiber, an aramid fiber is preferable from the viewpoint of heat resistance. Further, from the viewpoint of improving the strength of the underlay material, it is preferable that the organic fibers contain fibrillated organic fibers, and it is more preferable that they contain fibrillated aramid fibers. The fibrillated organic fiber is an organic fiber that has been split and has fluff, and is commercially available. Needless to say, the friction material composition for underlining material of the present invention may contain other organic fibers together with the fibrillated organic fibers.
When the friction material composition for underlining material of the present invention contains organic fibers (eg, fibrillated organic fibers), the content is preferably 1 to 8% by mass in the friction material composition for underlining material. The content is more preferably 2 to 7% by mass, and still more preferably 3 to 7% by mass. When the content is 1% by mass or more, good shear strength, crack resistance and abrasion resistance tend to be exhibited, and when the content is 8% by mass or less, the organic fibers (fibrillated organic) in the friction material composition for underlining material are used. Deterioration of shear strength and crack resistance due to uneven distribution of fibers and other materials can be effectively suppressed.
－無機繊維－
　無機繊維としては、例えば、ガラス繊維、繊維状ウォラストナイト、金属繊維、鉱物繊維、炭素繊維、セラミック繊維、生分解性セラミック繊維、ロックウール、チタン酸カリウム繊維、シリカアルミナ繊維、耐炎化繊維等が挙げられる。
　無機繊維は、金属及び金属合金以外の無機物を主成分とする繊維状の材料であることが好ましく、鉱物繊維であることがより好ましい。
　無機繊維は、１種を単独で使用してもよいし、２種以上を併用してもよい。 -Inorganic fiber-
Examples of the inorganic fiber include glass fiber, fibrous wollastonite, metal fiber, mineral fiber, carbon fiber, ceramic fiber, biodegradable ceramic fiber, rock wool, potassium titanate fiber, silica alumina fiber, and flame resistant fiber. Is mentioned.
The inorganic fiber is preferably a fibrous material mainly composed of an inorganic substance other than a metal and a metal alloy, and more preferably a mineral fiber.
One type of inorganic fiber may be used alone, or two or more types may be used in combination.
　ガラス繊維とは、ガラスを溶融及び紡糸して製造した繊維のことを指す。ガラス繊維は、原料がＥガラス、Ｃガラス、Ｓガラス、Ｄガラス等であるものを使用することができ、これらの中でも、特に高強度であるという観点から、Ｅガラス又はＳガラスを含有するガラス繊維を使用することが好ましい。また、結合材との親和性向上のため、ガラス繊維の表面をアミノシラン又はエポキシシラン等で処理したガラス繊維が好ましい。また、原料及び下張り材用摩擦材組成物のハンドリング性向上の観点から、ガラス繊維をウレタン樹脂、アクリル樹脂又はフェノール樹脂等で収束したものを用いることができ、収束本数は５０～１，０００本であることが好ましく、分散性及びハンドリング性のバランスの観点から、５０～５００本であることがより好ましい。
　前記ガラス繊維の平均繊維長は、特に制限されるものではないが、好ましくは８０～６，０００μｍ、より好ましくは１５０～５，０００μｍ、さらに好ましくは３００～５，０００μｍ、特に好ましくは１，０００～５，０００μｍ、最も好ましくは２，０００～４，０００μｍである。平均繊維長が８０μｍ以上であれば、下張り材の強度が向上する傾向にあり、６，０００μｍ以下であれば、分散性の低下が抑制される傾向にある。また、前記ガラス繊維の平均繊維径は、好ましくは５～２０μｍ、より好ましくは７～１５μｍである。平均繊維径が５μｍ以上であれば、下張り材用摩擦材組成物の混合時にガラス繊維が折損することを抑制することができ、２０μｍ以下であれば、下張り材の強度が向上する傾向にある。本明細書において、平均繊維長及び平均繊維径はそれぞれ、用いる無機繊維を無作為に５０個選択し、光学顕微鏡で繊維長及び繊維径を測定し、それから求められる平均値を示すが、市販品であればカタログ値を参照できる。なお、本明細書において、繊維径は、繊維の直径を指す。 Glass fiber refers to a fiber produced by melting and spinning glass. As the glass fiber, a glass fiber whose raw material is E glass, C glass, S glass, D glass, or the like can be used. Among them, a glass containing E glass or S glass from the viewpoint of particularly high strength. Preferably, fibers are used. Further, glass fibers obtained by treating the surfaces of glass fibers with aminosilane, epoxysilane, or the like are preferable for improving the affinity with the binder. Further, from the viewpoint of improving the handling properties of the raw material and the friction material composition for the underlaying material, a glass fiber obtained by converging a glass fiber with a urethane resin, an acrylic resin, a phenol resin or the like can be used. The number is preferably 50 to 500 from the viewpoint of the balance between dispersibility and handleability.
The average fiber length of the glass fiber is not particularly limited, but is preferably from 80 to 6,000 μm, more preferably from 150 to 5,000 μm, still more preferably from 300 to 5,000 μm, and particularly preferably from 1,000 to 1,000 μm. 5,000 μm, and most preferably 2,000-4,000 μm. If the average fiber length is 80 µm or more, the strength of the underlay material tends to be improved, and if it is 6,000 µm or less, a decrease in dispersibility tends to be suppressed. The average fiber diameter of the glass fiber is preferably 5 to 20 μm, more preferably 7 to 15 μm. When the average fiber diameter is 5 μm or more, breakage of the glass fiber at the time of mixing the friction material composition for underlining material can be suppressed, and when it is 20 μm or less, the strength of the underlining material tends to be improved. In the present specification, the average fiber length and the average fiber diameter, respectively, randomly select 50 inorganic fibers to be used, measure the fiber length and the fiber diameter with an optical microscope, and show the average value obtained therefrom, If so, you can refer to the catalog value. In addition, in this specification, a fiber diameter points out the diameter of a fiber.
　前記繊維状ウォラストナイトは、ＣａＳｉＯ３を主成分とする天然に産出されるケイ酸塩鉱物を粉砕分級し、繊維状に加工したものを指す。本発明で使用する繊維状ウォラストナイトの平均アスペクト比（平均繊維長／平均繊維径）は好ましくは８以上であり、より好ましくは８～２０、さらに好ましくは９～２０、特に好ましくは１０～１８である。平均アスペクト比を８以上とすることで、下張り材の常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。
　繊維状ウォラストナイトの平均繊維長は、下張り材への強度付与の観点から、好ましくは２０～１，０００μｍ、より好ましくは４０～８５０μｍ、さらに好ましくは１００～８５０μｍである。繊維状ウォラストナイトの平均繊維径は、下張り材への強度付与の観点から、好ましくは７０μｍ以下、より好ましくは６０μｍ以下である。平均繊維径の下限値に特に制限はないが、好ましくは５μｍ以上、より好ましくは８μｍ以上である。また、結合材との親和性を高めるため、繊維状ウォラストナイトの表面は、アミノシラン、エポキシシラン等で処理されていてもよい。 The fibrous wollastonite refers to one obtained by pulverizing and classifying a naturally occurring silicate mineral containing CaSiO 3 as a main component and processing it into a fibrous form. The average aspect ratio (average fiber length / average fiber diameter) of the fibrous wollastonite used in the present invention is preferably 8 or more, more preferably 8 to 20, further preferably 9 to 20, and particularly preferably 10 to 20. Eighteen. By setting the average aspect ratio to 8 or more, the shear strength and the crack resistance at room temperature of the underlay material can be effectively improved. Here, the average aspect ratio means a d50 value (cumulative median value of the volume distribution), and can be measured by, for example, a dynamic image analysis method.
The average fiber length of the fibrous wollastonite is preferably from 20 to 1,000 μm, more preferably from 40 to 850 μm, and still more preferably from 100 to 850 μm, from the viewpoint of imparting strength to the underlaying material. The average fiber diameter of the fibrous wollastonite is preferably 70 μm or less, more preferably 60 μm or less, from the viewpoint of imparting strength to the underlaying material. The lower limit of the average fiber diameter is not particularly limited, but is preferably 5 μm or more, more preferably 8 μm or more. Further, in order to increase the affinity with the binder, the surface of the fibrous wollastonite may be treated with aminosilane, epoxysilane, or the like.
　前記金属繊維としては、アルミニウム、鉄、亜鉛、錫、チタン、ニッケル、マグネシウム等の金属単体又は合金形態の繊維、鋳鉄等の金属を主成分とする繊維などが挙げられる。合金形態の繊維（合金繊維）としては、鉄合金繊維、アルミニウム合金繊維等が挙げられる。金属繊維は１種を単独で使用してもよいし、２種以上を併用してもよい。本発明においては、金属繊維を含有しない下張り材用摩擦材組成物が好ましい。
　強度向上、摩擦係数の安定化、熱伝導率の向上、耐クラック性及び耐摩耗性の向上の観点からは、一般的には、銅繊維、銅合金繊維、鉄繊維及び鉄合金繊維が好まれる。しかし、銅繊維又は銅合金繊維を含有させる場合、前述の通り環境汚染の問題を有するため、本発明では、下張り材用摩擦材組成物中における銅の含有量は、銅元素として０．５質量％未満とし、好ましくは０．３質量％以下、より好ましくは０．１質量％以下、さらに好ましくは実質的に銅を含まない態様である。なお、銅合金繊維としては、銅繊維、黄銅繊維、青銅繊維等が挙げられる。
　また、鉄繊維又は鉄合金繊維を含有させる場合、バックプレートとの接着界面での発錆による耐久性低下を抑制するため、本発明では、下張り材用摩擦材組成物中における鉄の含有量は、鉄元素として０．５質量％未満とすることが好ましく、より好ましくは０．３質量％以下、さらに好ましくは０．１質量％以下、特に好ましくは実質的に鉄を含まない態様である。 Examples of the metal fibers include fibers in the form of a single metal or alloy such as aluminum, iron, zinc, tin, titanium, nickel and magnesium, and fibers mainly containing a metal such as cast iron. Examples of the alloy-type fiber (alloy fiber) include an iron alloy fiber and an aluminum alloy fiber. One type of metal fiber may be used alone, or two or more types may be used in combination. In the present invention, a friction material composition for a subbing material containing no metal fibers is preferable.
From the viewpoint of improving strength, stabilizing the coefficient of friction, improving thermal conductivity, and improving crack resistance and wear resistance, copper fibers, copper alloy fibers, iron fibers and iron alloy fibers are generally preferred. . However, when copper fibers or copper alloy fibers are contained, there is a problem of environmental pollution as described above.In the present invention, the content of copper in the friction material composition for underlaying material is 0.5 mass% as a copper element. %, Preferably 0.3% by mass or less, more preferably 0.1% by mass or less, and further preferably substantially contains no copper. In addition, as a copper alloy fiber, a copper fiber, a brass fiber, a bronze fiber, etc. are mentioned.
Further, when containing iron fibers or iron alloy fibers, in order to suppress the decrease in durability due to rust at the bonding interface with the back plate, in the present invention, the iron content in the friction material composition for underlining material is The content of iron is preferably less than 0.5% by mass, more preferably 0.3% by mass or less, further preferably 0.1% by mass or less, and particularly preferably substantially no iron.
　前記鉱物繊維は、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、その他の天然岩石等を主成分として溶融紡糸した人造無機繊維である。鉱物繊維としては、例えば、ＳｉＯ２、Ａｌ２Ｏ３、ＣａＯ、ＭｇＯ、ＦｅＯ、Ｎａ２Ｏ等を含有する鉱物繊維、又はこれら化合物を１種もしくは２種以上含有する鉱物繊維等が挙げられる。鉱物繊維としては、アルミニウム元素を含む鉱物繊維が好ましく、Ａｌ２Ｏ３を含有する鉱物繊維がより好ましく、Ａｌ２Ｏ３とＳｉＯ２とを含有する鉱物繊維がさらに好ましい。
　下張り材用摩擦材組成物中に含まれる鉱物繊維の平均繊維長が大きくなるほど、せん断強度が低下する傾向にある。そのため、鉱物繊維の平均繊維長は、好ましくは５００μｍ以下、より好ましくは１００～４００μｍ、さらに好ましくは１２０～３４０μｍである。また、鉱物繊維の平均繊維径（直径）には特に制限はないが、通常、１～２０μｍであり、２～１５μｍであってもよい。 The mineral fibers are artificial inorganic fibers melt-spun with blast furnace slag such as slag wool, basalt such as basalt fiber, and other natural rocks as main components. Examples of the mineral fiber include a mineral fiber containing SiO 2 , Al 2 O 3 , CaO, MgO, FeO, Na 2 O, etc., or a mineral fiber containing one or more of these compounds. As the mineral fiber, a mineral fiber containing an aluminum element is preferred, a mineral fiber containing Al 2 O 3 is more preferred, and a mineral fiber containing Al 2 O 3 and SiO 2 is even more preferred.
The shear strength tends to decrease as the average fiber length of the mineral fibers included in the friction material composition for underlining materials increases. Therefore, the average fiber length of the mineral fibers is preferably 500 μm or less, more preferably 100 to 400 μm, and further preferably 120 to 340 μm. The average fiber diameter (diameter) of the mineral fibers is not particularly limited, but is usually 1 to 20 μm, and may be 2 to 15 μm.
　鉱物繊維は、人体有害性の観点から、生体溶解性であることが好ましい。ここでいう生体溶解性の鉱物繊維とは、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鉱物繊維である。具体的には、化学組成が、アルカリ酸化物及びアルカリ土類酸化物の総量（ナトリウム、カリウム、カルシウム、マグネシウム及びバリウムの酸化物の総量）が１８質量％以上で、且つ、（ａ）短期吸入暴露による生体内耐久試験で、長さが２０μｍ超の繊維の半減期が１０日未満であること、（ｂ）短期気管内注入による生体内耐久試験で、長さが２０μｍ超の繊維の半減期が４０日未満であること、（ｃ）腹腔内投与試験で有意な発ガン性が無いこと、又は、（ｄ）長期吸入暴露試験で発ガン性と結びつく病理所見又は腫瘍形成が無いこと、のいずれかを満たす繊維（ＥＵ指令９７／６９／ＥＣのＮｏｔａ　Ｑ（発癌性適用除外）参照）を示す。このような生体分解性鉱物繊維としては、ＳｉＯ２－Ａｌ２Ｏ３－ＣａＯ－ＭｇＯ－ＦｅＯ（－Ｋ２Ｏ－Ｎａ２Ｏ）系繊維等が挙げられ、ＳｉＯ２、Ａｌ２Ｏ３、ＣａＯ、ＭｇＯ、ＦｅＯ、Ｋ２Ｏ及びＮａ２Ｏ等から選択される少なくとも２種を任意の組み合わせで含有する鉱物繊維が挙げられる。 The mineral fibers are preferably biosoluble from the viewpoint of harmful effects on the human body. The term "biosoluble mineral fiber" as used herein refers to a mineral fiber that has the characteristic of being partially decomposed in a short time and discharged out of the body even when taken into the human body. Specifically, the chemical composition is such that the total amount of alkali oxides and alkaline earth oxides (total amount of sodium, potassium, calcium, magnesium and barium oxides) is 18% by mass or more, and (a) short-term inhalation The half-life of a fiber having a length of more than 20 μm is less than 10 days in an in vivo durability test by exposure, and (b) a half-life of a fiber having a length of more than 20 μm in an in vivo durability test by short-term intratracheal injection. Less than 40 days, (c) no significant carcinogenicity in the intraperitoneal administration test, or (d) no pathological findings or tumor formation associated with carcinogenicity in the long-term inhalation exposure test. Fibers satisfying either (see EU Directive 97/69 / EC, Nota Q (exclusion of carcinogenicity)). Examples of such biodegradable mineral fibers include SiO 2 —Al 2 O 3 —CaO—MgO—FeO (—K 2 O—Na 2 O) fibers and the like, and include SiO 2 , Al 2 O 3 , and CaO. , MgO, FeO, K 2 O, Na 2 O and the like.
　前記炭素繊維としては、耐炎化繊維、ピッチ系炭素繊維、ＰＡＮ系炭素繊維、活性炭繊維等が挙げられる。炭素繊維は、１種を単独で使用してもよいし、２種以上を併用してもよい。炭素繊維の平均繊維長に特に制限はないが、好ましくは０．１～６．０ｍｍ、より好ましくは０．１～３．０ｍｍである。平均繊維長が前記範囲であれば下張り材が欠けにくく、強度が保たれ易い。また、炭素繊維の平均繊維径に特に制限はないが、好ましくは５～２０μｍである。 Examples of the carbon fibers include flame-resistant fibers, pitch-based carbon fibers, PAN-based carbon fibers, and activated carbon fibers. One type of carbon fiber may be used alone, or two or more types may be used in combination. The average fiber length of the carbon fibers is not particularly limited, but is preferably 0.1 to 6.0 mm, and more preferably 0.1 to 3.0 mm. When the average fiber length is in the above range, the underlay material is not easily chipped, and the strength is easily maintained. The average fiber diameter of the carbon fibers is not particularly limited, but is preferably 5 to 20 μm.
　本発明の下張り材用摩擦材組成物が無機繊維（例えば鉱物繊維）を含有する場合、その含有量は、下張り材用摩擦材組成物中、３～４０質量％であることが好ましく、８～３０質量％であることがより好ましく、１０～３０質量％であることがさらに好ましく、１５～２５質量％であることが特に好ましい。 When the friction material composition for underlining material of the present invention contains inorganic fibers (for example, mineral fibers), the content is preferably 3 to 40% by mass, and more preferably 8 to 40% by mass of the friction material composition for underlining material. The content is more preferably 30% by mass, further preferably 10 to 30% by mass, and particularly preferably 15 to 25% by mass.
　また、下張り材用摩擦材組成物における繊維基材の含有量は、下張り材用摩擦材組成物中、好ましくは５～４０質量％、より好ましくは５～３５質量％、さらに好ましくは１５～３５質量％である。繊維基材の含有量を上記範囲とすることで、下張り材としての最適な気孔率が得られ、鳴き防止ができ、適正な材料強度が得られ、耐摩耗性を向上し、さらに成形性を向上させることができる傾向にある。 The content of the fibrous base material in the friction material composition for underlining material is preferably 5 to 40% by mass, more preferably 5 to 35% by mass, and still more preferably 15 to 35% by mass in the friction material composition for underlining material. % By mass. By setting the content of the fibrous base material within the above range, an optimum porosity as an underlay material can be obtained, squeal can be prevented, appropriate material strength can be obtained, abrasion resistance can be improved, and formability can be further improved. There is a tendency that can be improved.
（結合材）
　結合材は、下張り材用摩擦材組成物に含まれ得る有機充填材、無機充填材及び繊維基材等を結合して一体化し、所定の形状と強度を与える機能を有する。本発明の下張り材用摩擦材組成物に含まれる結合材に特に制限はないが、下張り材の結合材として一般的に用いられる熱硬化性樹脂を用いることができる。
　該熱硬化性樹脂としては、例えば、フェノール樹脂、変性フェノール樹脂、エラストマー分散フェノール樹脂、エポキシ樹脂、ポリイミド樹脂、メラミン樹脂等が挙げられる。ここで、変性フェノール樹脂としては、アクリル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及びアルキルベンゼン変性フェノール樹脂等が挙げられる。エラストマー分散フェノール樹脂としては、アクリルエラストマー分散フェノール樹脂、シリコーンエラストマー分散フェノール樹脂等が挙げられる。
　特に、良好な耐熱性、成形性及び摩擦係数を与えることから、フェノール樹脂、アクリル変性フェノール樹脂、シリコーン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が好ましく、フェノール樹脂がより好ましい。
　熱硬化性樹脂は、１種を単独で使用してもよいし、２種以上を併用してもよい。 (Binder)
The binder has a function of binding and integrating an organic filler, an inorganic filler, a fiber base material, and the like, which can be included in the friction material composition for an underlining material, and giving a predetermined shape and strength. The binder contained in the friction material composition for underlining material of the present invention is not particularly limited, but a thermosetting resin generally used as a binding material for underlining material can be used.
Examples of the thermosetting resin include a phenol resin, a modified phenol resin, an elastomer-dispersed phenol resin, an epoxy resin, a polyimide resin, and a melamine resin. Here, examples of the modified phenol resin include an acrylic-modified phenol resin, a silicone-modified phenol resin, a cashew-modified phenol resin, an epoxy-modified phenol resin, and an alkylbenzene-modified phenol resin. Examples of the elastomer-dispersed phenolic resin include an acrylic elastomer-dispersed phenolic resin and a silicone elastomer-dispersed phenolic resin.
In particular, a phenol resin, an acryl-modified phenol resin, a silicone-modified phenol resin, and an alkylbenzene-modified phenol resin are preferable, and a phenol resin is more preferable, since they provide good heat resistance, moldability, and friction coefficient.
One thermosetting resin may be used alone, or two or more thermosetting resins may be used in combination.
　下張り材用摩擦材組成物が結合材を含有する場合、その含有量は、下張り材用摩擦材組成物中、好ましくは５～２５質量％、より好ましくは５～２０質量％、さらに好ましくは６～１８質量％、特に好ましくは８～１６質量％である。結合材の含有量を上記範囲とすることで、下張り材の強度を保ち、弾性率が高くなることによる鳴き等の制振性悪化をより抑制できる。 When the friction material composition for underlining material contains a binder, the content thereof is preferably 5 to 25% by mass, more preferably 5 to 20% by mass, and still more preferably 6 to 25% by mass in the friction material composition for underlining material. It is preferably from 18 to 18% by mass, particularly preferably from 8 to 16% by mass. By setting the content of the binder in the above range, the strength of the underlaying material can be maintained, and deterioration in vibration damping properties such as squealing due to an increase in elastic modulus can be further suppressed.
（その他の材料）
　本発明の下張り材用摩擦材組成物は、前記各成分以外に、必要に応じてその他の材料を配合することができる。
　その他の材料としては、例えば、耐摩耗性及び熱フェード特性向上の観点から、亜鉛粉及びアルミ等の金属粉末；ポリテトラフルオロエチレン（ＰＴＦＥ）等のフッ素系ポリマー、などの有機添加剤が挙げられる。
　本発明の下張り材用摩擦材組成物が上記その他の材料を含有する場合、その含有量としては、下張り用摩擦材組成物中、それぞれ、好ましくは２０質量％以下、より好ましくは１０質量％以下、さらに好ましくは５質量％以下、特に好ましくは３質量％以下であり、その他の材料を含有していなくてもよい。 (Other materials)
In the friction material composition for underlining material of the present invention, other materials can be blended, if necessary, in addition to the above components.
Examples of other materials include organic additives such as metal powders such as zinc powder and aluminum; and fluorine-based polymers such as polytetrafluoroethylene (PTFE), from the viewpoint of improving abrasion resistance and thermal fade characteristics. .
When the friction material composition for underlining material of the present invention contains the above-mentioned other materials, the content is preferably 20% by mass or less, more preferably 10% by mass or less, respectively, in the friction material composition for underlining material. The content is more preferably 5% by mass or less, particularly preferably 3% by mass or less, and may not contain other materials.
　次に、前記下張り材の上に設けられる摩擦材（上張り材）２について詳述する。該「上張り材用摩擦材組成物」が含有し得る各成分は、「摩擦材（上張り材）」が含有し得る成分ということになる。つまり、後述する「上張り材用摩擦材組成物」中の各成分に関する説明は、「上張り材」中の各成分に関する説明として読み替えることができる。
［上張り材用摩擦材組成物］
　摩擦材（上張り材）２の材料となる上張り材用摩擦材組成物としては、公知の上張り材用摩擦材組成物を利用することができ、特に制限はない。上張り材用摩擦材組成物としては、具体的には、有機充填材、無機充填材、繊維基材及び結合材を含有する上張り材用摩擦材組成物であって、該上張り材用摩擦材組成物は、銅を含まないか、又は銅を含んでいても該銅の含有率は銅元素として０．５質量％未満であることが好ましい。有機充填材、無機充填材、繊維基材及び結合材については、前記下張り材用摩擦材組成物において説明したものと同様のものを使用することができる。 Next, the friction material (upper material) 2 provided on the lower lining material will be described in detail. Each component that can be contained in the “friction material composition for overlay” is a component that can be contained in the “friction material (overlay)”. In other words, the description of each component in the “friction material composition for overlay” described later can be read as the description of each component in the “overlay material”.
[Friction material composition for overlay material]
As the friction material composition for the upper material used as the material of the friction material (upper material) 2, a known friction material composition for the upper material can be used, and there is no particular limitation. Specific examples of the friction material composition for an overlay material include a friction material composition for an overlay material containing an organic filler, an inorganic filler, a fiber base material, and a binder. The friction material composition preferably does not contain copper, or even if it contains copper, the content of copper is preferably less than 0.5% by mass as a copper element. As the organic filler, the inorganic filler, the fiber base material, and the binder, the same ones as described in the above-described friction material composition for underlining material can be used.
（摩擦材２及び下張り材３の製造方法）
　図３を用いて説明すると、上張り材用摩擦材組成物と本発明の下張り材用摩擦材組成物とを、一般に使用されている方法、好ましくは加熱加圧成形によって成形することで、上張り材（摩擦材）２と下張り材３とを一体化することができる。 (Method of manufacturing friction material 2 and underlay material 3)
Referring to FIG. 3, the friction material composition for an overlay material and the friction material composition for an underlay material of the present invention are molded by a generally used method, preferably by heating and pressing. The upholstery (frictional material) 2 and the lower lining 3 can be integrated.
　より詳細には、上張り材用摩擦材組成物と本発明の下張り材用摩擦材組成物をそれぞれ別々に、レーディゲミキサー（「レーディゲ」は登録商標）、加圧ニーダー、アイリッヒミキサー（「アイリッヒ」は登録商標）等の混合機を用いて混合し、上張り材用混合物と下張り材用混合物とを成形金型にて一体で予備成形し、次いで、得られた予備成形物を例えば成形温度１３０～１６０℃、成形圧力２０～５０ＭＰａの条件で２～１０分間で成形し、得られた成形物を例えば１５０～２５０℃で２～１０時間熱処理することで、上張り材（摩擦材）２と下張り材３とを一体化することができる。また、必要に応じて、塗装、スコーチ処理、研磨処理を行ってもよい。上記工程の中で、予備成形工程を省略して混合物を直接熱成形してもよい。 More specifically, the friction material composition for an overlay material and the friction material composition for an underlay material of the present invention are separately prepared by using a Reidige mixer (“Redige” is a registered trademark), a pressure kneader, an Erich mixer ( "Eirich" is a registered trademark) mixed using a mixer such as, the mixture for the upper material and the mixture for the lower material are pre-formed integrally in a molding die, and then the obtained pre-formed product is, for example, Molding is performed at a molding temperature of 130 to 160 ° C. under a molding pressure of 20 to 50 MPa for 2 to 10 minutes, and the obtained molded product is heat-treated at, for example, 150 to 250 ° C. for 2 to 10 hours, so that an upper material (friction material 2) and the underlay material 3 can be integrated. Moreover, you may perform a coating, a scorch process, and a grinding | polishing process as needed. In the above steps, the mixture may be directly thermoformed without the preforming step.
［摩擦部材］
　図３を用いて説明すると、本発明の下張り材用摩擦材組成物は、常温における高いせん断強度と高い耐クラック性と優れた耐摩耗性とを有し、さらに繰り返し制動後のバックプレートの耐久性を向上させるため、摩擦部材の下張り材３として用いることができる。ここで、上張り材（摩擦材）２は、摩擦部材の摩擦面となる摩擦材であり、下張り材３は、摩擦部材の摩擦面となる上張り材（摩擦材）２とバックプレート１との間に介在する、上張り材（摩擦材）２とバックプレート１との接着部付近のせん断強度及び耐クラック性向上を目的とした層のことである。 [Friction member]
Referring to FIG. 3, the friction material composition for underlining material of the present invention has high shear strength at room temperature, high crack resistance and excellent abrasion resistance, and furthermore, the durability of the back plate after repeated braking. In order to improve the performance, it can be used as a subbing material 3 for a friction member. Here, the upper lining material (friction material) 2 is a friction material serving as a friction surface of the friction member, and the lower lining material 3 is formed of an upper lining material (friction material) 2 serving as a friction surface of the friction member and the back plate 1. It is a layer interposed therebetween for the purpose of improving the shear strength and crack resistance near the bonding portion between the overlay material (friction material) 2 and the back plate 1.
　本発明の摩擦部材は、本発明の下張り材を用いながら、上張り材が摩擦面となるように形成した摩擦部材であって、つまり、下張り材が摩擦面とは反対側に位置する摩擦部材である。本発明の摩擦部材としては、上記態様に限らず、例えば、（１）摩擦材（上張り材）２とバックプレート１と下張り材３とを有し、該バックプレート１上に、下張り材３を介して上張り材２が摩擦面側に位置するように設けられた摩擦部材（上記態様と同じ。）、及び（２）前記（１）の構成の摩擦部材において、バックプレート１と下張り材３との間に、バックプレート１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を介在させた摩擦部材等が挙げられる。さらに、（３）上記（１）又は（２）の構成の摩擦部材において、前記バックプレート１において、前記下張り材３を有する側とは反対側にシムを有する摩擦部材も挙げられる。該シムは、一般的に摩擦部材の制振性向上のために用いられるスペーサーである。 The friction member of the present invention is a friction member formed by using the underlining material of the present invention so that the upper surface becomes a friction surface, that is, the friction member in which the underlining material is located on the opposite side to the friction surface. It is. The friction member of the present invention is not limited to the above-described embodiment, and includes, for example, (1) a friction material (upper material) 2, a back plate 1, and a lower material 3, and the lower material 3 is provided on the back plate 1. In the friction member (same as the above-mentioned embodiment) provided so that the upper material 2 is located on the friction surface side through the intermediary of the back plate 1 and the lower material, 3 and a friction member with a primer layer interposed therebetween for the purpose of surface modification for enhancing the adhesive effect of the back plate 1. (3) In the friction member having the configuration of (1) or (2), a friction member having a shim on the back plate 1 on the side opposite to the side having the underlining material 3 may also be mentioned. The shim is a spacer generally used for improving the vibration damping of the friction member.
　摩擦材（上張り材）２の厚みは、耐久性の観点から、好ましくは４～１５ｍｍ、より好ましくは５～１４ｍｍ、さらに好ましくは５～１２ｍｍである。
　また、下張り材３の厚みは、好ましくは１ｍｍ以上、より好ましくは１～５ｍｍ、さらに好ましくは１～３ｍｍである。
　摩擦面から垂直方向に見たとき、上張り材（摩擦材）２と下張り材３との合計厚みに対する下張り材３の厚みの割合は３～７０％であることが好ましく、５～６０％であることがより好ましく、６～５０％であることがさらに好ましい。 The thickness of the friction material (overlaying material) 2 is preferably 4 to 15 mm, more preferably 5 to 14 mm, and still more preferably 5 to 12 mm from the viewpoint of durability.
The thickness of the underlining material 3 is preferably 1 mm or more, more preferably 1 to 5 mm, and still more preferably 1 to 3 mm.
When viewed in the vertical direction from the friction surface, the ratio of the thickness of the underlining material 3 to the total thickness of the uppering material (friction material) 2 and the underlining material 3 is preferably 3 to 70%, and preferably 5 to 60%. More preferably, it is more preferably 6 to 50%.
　本発明の摩擦部材は、自動車等のディスクブレーキパッドの摩擦部材、自動車等のブレーキライニングの摩擦部材として使用することができる。また、上張り材用摩擦材組成物と本発明の下張り材用摩擦材組成物を目的形状に成形、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部材としても使用することができる。
　本発明の摩擦部材は、その下張り材が、常温におけるせん断強度と、耐クラック性とを共に満足させることができ、且つ耐摩耗性にも優れるため、特に車用の摩擦部材として好適である。 INDUSTRIAL APPLICABILITY The friction member of the present invention can be used as a friction member for a disc brake pad of an automobile or the like and a friction member for a brake lining of an automobile or the like. Further, the friction material composition for an overlay material and the friction material composition for an underlay material of the present invention are subjected to molding, processing, pasting, and the like into a target shape, so that the friction of a clutch facing, an electromagnetic brake, a holding brake, etc. It can also be used as a member.
The friction member of the present invention is suitable as a friction member for a vehicle, because the underlining material can satisfy both the shear strength at normal temperature and the crack resistance and has excellent wear resistance.
［車］
　本発明は、本発明の摩擦部材を搭載した車も提供する。例えば、本発明の摩擦部材を、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等が挙げられる。車としては、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、大型自動二輪車及び普通自動二輪車等の自動車が挙げられる。 [car]
The present invention also provides a vehicle equipped with the friction member of the present invention. For example, there is a car using the friction member of the present invention for a disc brake pad, a brake lining, a clutch facing, an electromagnetic brake, a holding brake, and the like. Examples of the car include large cars, medium cars, ordinary cars, large special cars, small special cars, large motorcycles and ordinary motorcycles.
　以下、本発明を実施例によりさらに詳細に説明するが、本発明はこれらの例によって何ら制限を受けるものではない。 Hereinafter, the present invention will be described in more detail with reference to Examples, but the present invention is not limited by these Examples.
　実施例及び比較例の各摩擦材試料について、以下の評価方法に従って評価を行った。
［評価方法］
（１）せん断強度の測定
　各例で作製したディスクブレーキパッドについて、ＪＩＳ　Ｄ４４２２（２００７年）に準拠して、常温（２５℃）におけるせん断強度を測定した。 Each of the friction material samples of Examples and Comparative Examples was evaluated according to the following evaluation method.
[Evaluation method]
(1) Measurement of Shear Strength The shear strength at room temperature (25 ° C.) of the disc brake pad produced in each example was measured in accordance with JIS D4422 (2007).
　（２）熱伝導率
　各例にて上張り材及び下張り材をそれぞれ単独で成形した後、直径５０ｍｍ、厚み２ｍｍの円柱状に切り出して測定用試料を作製し、２本の金属製の円柱で測定用試料の底面を挟み、大気圧下で、室温（２５℃）における温度傾斜法（株式会社アグネ技術センター製の熱伝導率測定装置「ＡＲＣ－ＴＣ－１」）にて測定した。なお、このとき試料に接する２本の金属製の円柱の温度差は１３～２０℃、平均温度は２５℃であった。
　バックプレートの熱伝導率については、公称値を表２に示した。 (2) Thermal conductivity In each example, the upper and lower substrates were individually formed, and then cut out into a cylinder having a diameter of 50 mm and a thickness of 2 mm to prepare a measurement sample. The bottom surface of the measurement sample was sandwiched, and the measurement was carried out under atmospheric pressure at room temperature (25 ° C.) by a temperature gradient method (Arc-TC-1 thermal conductivity measuring device manufactured by Agne Technology Center Co., Ltd.). At this time, the temperature difference between the two metal cylinders in contact with the sample was 13 to 20 ° C., and the average temperature was 25 ° C.
Nominal values are shown in Table 2 for the thermal conductivity of the back plate.
（３）繰り返し制動におけるバックプレートの耐久性試験及びバックプレートの温度
　各例で作製したディスクブレーキパッドを用いてブレーキダイナモ試験を行い、バックプレートの耐久性の評価を行った。評価にあたっては、一般的なピンスライド式のコレット対応のキャリパー、ベンチレーテッドディスクローターを用い、イナーシャ７ｋｇｆ・ｍ・ｓ２の条件で評価を行った。車速６５ｋｍ／ｈ、減速度０．３５Ｇの制動を５０回繰り返し、ブレーキディスク温度が６００℃まで昇温するサイクルを５０回繰り返した後、バックプレート部の外観の欠陥（折損、変形、クラック）の有無を確認し、下記評価基準に従って評価した。
　また、バックプレートの温度については、バックプレート中に埋め込んだ熱電対で計測した。
ａ：バックプレート部の折損、１ｍｍを超える変形、及びクラックの発生がいずれも無い。
ｂ：バックプレート部の折損及び１ｍｍを超える変形は無いが、クラックが発生した。
ｃ：バックプレート部の折損又は１ｍｍを超える変形が生じた。 (3) Durability test of back plate and temperature of back plate during repeated braking A brake dynamo test was performed using the disc brake pads produced in each example to evaluate the durability of the back plate. In the evaluation, a general pin-slide type caliper compatible with a collet and a ventilated disc rotor were used, and the evaluation was performed under the condition of inertia 7 kgf · m · s 2 . After repeating 50 cycles of braking at a vehicle speed of 65 km / h and a deceleration of 0.35 G, and repeating 50 cycles of raising the brake disk temperature to 600 ° C., the appearance of defects (breakage, deformation, cracks) in the back plate portion was reduced. The presence or absence was confirmed and evaluated according to the following evaluation criteria.
The temperature of the back plate was measured with a thermocouple embedded in the back plate.
a: No breakage of the back plate portion, no deformation exceeding 1 mm, and no occurrence of cracks.
b: There was no breakage of the back plate portion and no deformation exceeding 1 mm, but cracks occurred.
c: Breakage of the back plate portion or deformation exceeding 1 mm occurred.
［ディスクブレーキパッドの作製］
　ディスクブレーキパッドの作製にあたり、下記の摩擦材組成物の成分を用意した。表１及び表２中に記載の各成分は、以下のものと同じである。
（結合材）
・フェノール樹脂
（有機充填材）
・カシューパーティクル
・タイヤトレッドゴムの粉砕粉
・ＮＢＲ粉
（空隙を有する粒子）
・中空ガラス粒子：空隙率７５体積％、平均粒子径３０μｍ
・ケイ酸カルシウム粒子：平均粒子径６０μｍ
・γ－アルミナ粒子：平均粒子径２００μｍ
（無機充填材）
・チタン酸カリウム
・酸化ジルコニウム
・マイカ
・硫化スズ
・硫酸バリウム
・水酸化カルシウム
・黒鉛
（繊維基材）
・アラミド繊維（有機繊維）：フィブリル化アラミド繊維
（無機繊維）
・鉱物繊維：平均繊維長２３０±５０μｍ [Production of disc brake pad]
In producing the disc brake pad, the following components of the friction material composition were prepared. Each component described in Table 1 and Table 2 is the same as the following.
(Binder)
・ Phenolic resin (organic filler)
・ Cashew particles ・ Pulverized powder of tire tread rubber ・ NBR powder (particles with voids)
-Hollow glass particles: porosity 75% by volume, average particle diameter 30 µm
・ Calcium silicate particles: average particle diameter 60 μm
・ Γ-alumina particles: average particle diameter 200 μm
(Inorganic filler)
-Potassium titanate-Zirconium oxide-Mica-Tin sulfide-Barium sulfate-Calcium hydroxide-Graphite (fiber base material)
・ Aramid fiber (organic fiber): Fibrillated aramid fiber (inorganic fiber)
・ Mineral fiber: average fiber length 230 ± 50 μm
実施例１～７及び比較例１
　表１に示す配合量に従って各成分を配合し、上張り材用摩擦材組成物を得た。また、表２に示す配合量に従って各成分を配合し、下張り材用摩擦材組成物を得た。
　この上張り材用摩擦材組成物と下張り材用摩擦材組成物をそれぞれ別々に「レーディゲ（登録商標）ミキサーＭ２０」（商品名、株式会社マツボー製）で混合し、上張り材用混合物と下張り材用混合物を得た。得られた上張り材用混合物と下張り材用混合物を一体で成形プレス（王子機械株式会社製）にて予備成形した。得られた予備成形物を成形温度１４０～１６０℃、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）を用いて表２に示した材質のバックプレートと共に加熱加圧成形した。得られた成形品を２００℃で４．５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を得た。なお、実施例及び比較例で得たディスクブレーキパッドは、バックプレートの厚さ６ｍｍ、上張り材の厚さ６ｍｍ、下張り材の厚さ２ｍｍ、摩擦材投影面積５２ｃｍ２である。
　得られたディスクブレーキパッドを用いて、前記方法に従って各測定及び評価を行った。結果を表２に示す。 Examples 1 to 7 and Comparative Example 1
Each component was blended according to the blending amounts shown in Table 1 to obtain a friction material composition for an upholstery material. Further, the respective components were blended in accordance with the blending amounts shown in Table 2 to obtain a friction material composition for an underlining material.
The friction material composition for the overlay material and the friction material composition for the underlay material are separately mixed with a “REDIGE (registered trademark) mixer M20” (trade name, manufactured by Matsubo Corporation), and the mixture for the overlay material and the underlay are mixed. A wood mix was obtained. The obtained mixture for the overlay material and the mixture for the underlay material were integrally preformed by a molding press (manufactured by Oji Machine Co., Ltd.). The obtained preformed product was heated together with a back plate of the material shown in Table 2 using a molding press (manufactured by Sanki Seiko Co., Ltd.) under the conditions of a molding temperature of 140 to 160 ° C., a molding pressure of 30 MPa, and a molding time of 5 minutes. It was molded under pressure. The obtained molded article was heat-treated at 200 ° C. for 4.5 hours, polished using a rotary polisher, and scorched at 500 ° C. to obtain a disc brake pad. The disc brake pads obtained in Examples and Comparative Examples had a back plate thickness of 6 mm, an upper material thickness of 6 mm, a lower material thickness of 2 mm, and a friction material projected area of 52 cm 2 .
Using the obtained disc brake pads, each measurement and evaluation were performed according to the above-described methods. Table 2 shows the results.
Figure JPOXMLDOC01-appb-T000001
Figure JPOXMLDOC01-appb-T000001
Figure JPOXMLDOC01-appb-T000002
Figure JPOXMLDOC01-appb-T000002
　以下は、表２中に記載された、各例に用いたバックプレートの材質である。
　Ａｌ合金（アルミニウム合金）：Ａ５０８３（Ａｌ－Ｍｇ系合金）
　ＧＦＲＰ：２５ｍｍのガラス繊維で複合化したフェノール樹脂（ガラス繊維５０質量％）
　ＣＦＲＰ：２５ｍｍの炭素繊維で複合化したフェノール樹脂（炭素繊維５０質量％） The following is the material of the back plate used in each example described in Table 2.
Al alloy (aluminum alloy): A5083 (Al-Mg based alloy)
GFRP: phenolic resin composited with 25 mm glass fiber (glass fiber 50% by mass)
CFRP: phenolic resin composited with 25 mm carbon fiber (50% by mass of carbon fiber)
　表１中の実施例１～７より、バックプレートに耐熱性の劣る軽量素材を用い、下張り材には空隙を有する粒子を含有する下張り材を用いたディスクブレーキパッドは、せん断強度が高く、且つ、繰り返し制動を行ってもバックプレートの耐久性が高かった。バックプレートの耐久性が高くなったのは、繰り返し制動後のバックプレートの温度上昇が低減されたことに起因するものと推察する。
　一方、空隙を有する粒子を含有しない下張り材を用いた比較例１では、繰り返し制動後のバックプレートの耐久性が大幅に低下した。 According to Examples 1 to 7 in Table 1, the disc brake pad using a lightweight material having inferior heat resistance for the back plate and using an underlining material containing particles having voids for the underlining material has a high shear strength and The durability of the back plate was high even after repeated braking. The reason why the durability of the back plate has been increased is presumed to be that the temperature rise of the back plate after repeated braking was reduced.
On the other hand, in Comparative Example 1 using the underlaying material containing no particles having voids, the durability of the back plate after repeated braking was significantly reduced.
　本発明の摩擦部材は、繰り返し制動を行ってもバックプレートの温度上昇が小さく、実用的な耐久性を備え、且つ軽量であることから、二輪車又は四輪自動車の制動に用いられているディスクブレーキパッドとして好適である。 The friction member of the present invention has a small rise in temperature of the back plate even after repeated braking, has practical durability, and is light in weight. Therefore, a disc brake used for braking a two-wheeled or four-wheeled vehicle It is suitable as a pad.
１　　バックプレート
１１　バックプレートの摩擦材が配置される面
１２　バックプレートの他方の面
２　　摩擦材（上張り材）
３　　下張り材 1 back plate 11 surface on which friction material of back plate is arranged 12 other surface of back plate 2 friction material (overlaying material)
3 Underlay material

Claims (16)

  1. 　鋼より比重の軽い素材を含有するバックプレートの一方の面に摩擦材（上張り材）が下張り材を介して配置された摩擦部材であって、前記下張り材が空隙を有する粒子を含有する摩擦部材。 A friction member in which a friction material (upper material) is disposed on one surface of a back plate containing a material having a specific gravity lower than that of steel via a lower material, wherein the lower material contains particles having voids. Element.
  2. 　前記空隙を有する粒子の空隙率が３０体積％以上である、請求項１に記載の摩擦部材。 The friction member according to claim 1, wherein the porosity of the particles having voids is 30% by volume or more.
  3. 　前記空隙を有する粒子が、フライアッシュバルーン、シラスバルーン、珪藻土、中空ガラス粒子、ケイ酸カルシウム粒子、中空シリカ粒子、アルミナバルーン、ジルコニアバルーン、γ－アルミナ粒子及びフェノール樹脂バルーンからなる群から選択される少なくとも１種である、請求項１又は２に記載の摩擦部材。 The particles having voids are selected from the group consisting of fly ash balloons, shirasu balloons, diatomaceous earth, hollow glass particles, calcium silicate particles, hollow silica particles, alumina balloons, zirconia balloons, γ-alumina particles, and phenolic resin balloons. The friction member according to claim 1, wherein the friction member is at least one kind.
  4. 　前記下張り材における前記空隙を有する粒子の含有量が０．１～３０質量％である、請求項１～３のいずれか１項に記載の摩擦部材。 (4) The friction member according to any one of (1) to (3), wherein the content of the particles having voids in the underlining material is 0.1 to 30% by mass.
  5. 　前記バックプレートが含有する素材の比重が５Ｍｇ／ｍ３以下である、請求項１～４のいずれか１項に記載の摩擦部材。 The friction member according to any one of claims 1 to 4, wherein the specific gravity of the material contained in the back plate is 5 Mg / m 3 or less.
  6. 　前記バックプレートが、（１）繊維強化樹脂、（２－１）アルミニウム合金、（２－２）アルミニウムもしくはアルミニウム合金中にセラミックス粒子が分散するアルミニウム複合材、（３－１）マグネシウム合金、及び（３－２）マグネシウムもしくはマグネシウム合金中にセラミックス粒子が分散するマグネシウム複合材、からなる群から選択される少なくとも１種を含有する、請求項１～５のいずれか１項に記載の摩擦部材。 The back plate comprises (1) a fiber-reinforced resin, (2-1) an aluminum alloy, (2-2) an aluminum composite material in which ceramic particles are dispersed in aluminum or an aluminum alloy, (3-1) a magnesium alloy, and The friction member according to any one of claims 1 to 5, wherein the friction member contains at least one selected from the group consisting of 3-2) a magnesium composite material in which ceramic particles are dispersed in magnesium or a magnesium alloy.
  7. 　前記バックプレートが前記（１）繊維強化樹脂又は前記（２－１）アルミニウム合金を含有する、請求項６に記載の摩擦部材。 7. The friction member according to claim 6, wherein the back plate contains the (1) fiber-reinforced resin or the (2-1) aluminum alloy.
  8. 　請求項１～７のいずれか１項に記載の摩擦部材を含むディスクブレーキパッド。 A disc brake pad including the friction member according to any one of claims 1 to 7.
  9. 　請求項１～７のいずれか１項に記載の摩擦部材を搭載した車。 A vehicle equipped with the friction member according to any one of claims 1 to 7.
  10. 　空隙を有する粒子を含有する、下張り材用摩擦材組成物。 (4) A friction material composition for a subbing material, which contains particles having voids.
  11. 　前記空隙を有する粒子の空隙率が３０体積％以上である、請求項１０に記載の下張り材用摩擦材組成物。 The friction material composition for underlining material according to claim 10, wherein the porosity of the particles having voids is 30% by volume or more.
  12. 　前記空隙を有する粒子が、フライアッシュバルーン、シラスバルーン、珪藻土、中空ガラス粒子、ケイ酸カルシウム粒子、中空シリカ粒子、アルミナバルーン、ジルコニアバルーン、γ－アルミナ粒子及びフェノール樹脂バルーンからなる群から選択される少なくとも１種である、請求項１０又は１１に記載の下張り材用摩擦材組成物。 The particles having voids are selected from the group consisting of fly ash balloons, shirasu balloons, diatomaceous earth, hollow glass particles, calcium silicate particles, hollow silica particles, alumina balloons, zirconia balloons, γ-alumina particles, and phenolic resin balloons. The friction material composition for an underlining material according to claim 10, which is at least one kind.
  13. 　さらに有機充填材、無機充填材、繊維基材及び結合材からなる群から選択される少なくとも１種を含有する、請求項１０～１２のいずれか１項に記載の下張り材用摩擦材組成物。 The friction material composition for an underlining material according to any one of claims 10 to 12, further comprising at least one selected from the group consisting of an organic filler, an inorganic filler, a fiber base material, and a binder.
  14. 　銅を含有しないか、又は含有していても銅の含有量は銅元素として０．５質量％未満である、請求項１０～１３のいずれか１項に記載の下張り材用摩擦材組成物。 The friction material composition for an underlining material according to any one of claims 10 to 13, wherein copper is not contained, or even if copper is contained, the content of copper is less than 0.5% by mass as a copper element.
  15. 　請求項１０～１４のいずれか１項に記載の下張り材用摩擦材組成物を成形してなる下張り材。 An underlay material obtained by molding the friction material composition for an underlay material according to any one of claims 10 to 14.
  16. 　請求項１５に記載の下張り材を搭載した車。
          A vehicle equipped with the underlaying material according to claim 15.
PCT/JP2018/027778 2018-07-24 2018-07-24 Friction member, friction material composition for lower layer materials, lower layer material, disc brake pad and automobile WO2020021646A1 (en)

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