WO2018168980A1 - Method for producing friction material, and friction material - Google Patents

Method for producing friction material, and friction material Download PDF

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Publication number
WO2018168980A1
WO2018168980A1 PCT/JP2018/010113 JP2018010113W WO2018168980A1 WO 2018168980 A1 WO2018168980 A1 WO 2018168980A1 JP 2018010113 W JP2018010113 W JP 2018010113W WO 2018168980 A1 WO2018168980 A1 WO 2018168980A1
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Prior art keywords
friction material
friction
water
weight
absorbing polymer
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PCT/JP2018/010113
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French (fr)
Japanese (ja)
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拓央 吉田
勇太 小池
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株式会社アドヴィックス
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    • C—CHEMISTRY; METALLURGY
    • C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
    • C09K—MATERIALS FOR MISCELLANEOUS APPLICATIONS, NOT PROVIDED FOR ELSEWHERE
    • C09K3/00—Materials not provided for elsewhere
    • C09K3/14—Anti-slip materials; Abrasives
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
    • F16D—COUPLINGS FOR TRANSMITTING ROTATION; CLUTCHES; BRAKES
    • F16D69/00—Friction linings; Attachment thereof; Selection of coacting friction substances or surfaces
    • F16D69/02—Compositions of linings; Methods of manufacturing

Definitions

  • the present invention relates to a method of manufacturing a friction material and a friction material used for a brake device or the like for a vehicle.
  • Patent Document 1 if the negative gradient ( ⁇ -V negative gradient) of ⁇ (friction coefficient) with respect to V (vehicle speed) is reduced, occurrence of brake noise after leaving in a low temperature and high humidity environment It is disclosed to reduce.
  • the friction material contains zirconium oxide having a 50% particle diameter in the range of 0.1 to 5.0 ⁇ m as an abrasive at 15 to 35% by mass based on the total amount of the friction material composition, and other than zirconium oxide
  • the content of the abrasive having a Mohs hardness of 7.0 or more is 2.0 mass% or less with respect to the total amount of the friction material composition.
  • slaked lime is converted to quicklime (calcium oxide) when subjected to a heat history, and utilizes the feature of absorbing moisture to create cream under humid environment, and using slaked lime as a filler in a friction material It contains a large amount (at least 7 to 30% by volume) and contains a small amount (2.0 to 3.5% by volume) of aluminum particles.
  • quicklime calcium oxide
  • ME morning effect
  • Patent Document 3 describes that a friction material containing hydrophilic activated carbon as a friction modifier has a function of adsorbing sulfate ion and water.
  • the hydrophilic activated carbon is contained in an amount of 0.4 to 5.0% by weight based on the total amount of the friction material composition, and the average particle diameter thereof is 80 to 200 ⁇ m.
  • Patent Document 1 is highly aggressive to the rotor because the content of zirconium oxide in the friction material is as large as 15 to 35% by mass, and the wear of the rotor and disk thickness variation The deterioration of the brake vibration (shudder) due to the growth of the disc thickness deviation) is assumed.
  • the technique disclosed in Patent Document 2 contains a large amount of slaked lime, the flow inhibition of a binder such as a phenol resin becomes remarkable, and a decrease in the strength of the friction material is assumed.
  • Patent Document 3 uses activated carbon, the adsorption of water in a high humidity environment and the adsorption of liquid water such as condensed water become insufficient, and the occurrence of a brake noise phenomenon is effective. It is assumed that it can not be suppressed.
  • this invention makes it a subject to provide the manufacturing method and friction material of a friction material which can reduce generation
  • the inventors of the present invention conducted intensive studies to solve the above-mentioned problems, and by incorporating a powdery water-absorbing polymer at the time of production of the friction material, the influence of moisture at the time of braking after leaving in a high humidity environment. We focused on being able to minimize As a result, it has been found that the aggregation of the wear powder is suppressed, the increase in the true contact area with the rotor which is the opposite material of the friction material can be suppressed, and the occurrence of the squeal phenomenon can be reduced.
  • the method of manufacturing the friction material and the friction material relate to the following [1] and [2].
  • [1] A method of manufacturing a friction material, wherein the content of copper as an element is 0.5% by weight or less based on the entire friction material, A mixing step of mixing a friction material material containing a fibrous base material, a binder, an organic filler containing a powdery water-absorbing polymer, and an inorganic filler containing calcium hydroxide to obtain a friction material mixture , Forming the friction material raw material mixture obtained in the mixing step into a predetermined shape.
  • the friction material manufactured by the method of the above [1] can reduce the occurrence of the noise phenomenon at the time of initial brake operation in a high humidity environment. This is because the presence of the water absorbing polymer efficiently removes the water on the friction surface of the friction material and the rotor as the counterpart material, thereby suppressing the aggregation of the wear powder, and the true contact area between the friction material and the counterpart material. This is because the increase can be suppressed. Furthermore, by mixing a powdery water-absorbing polymer as a raw material of the friction material, the water-absorbing polymer easily remains without forming an irreversible ionic cross-link with a divalent metal ion derived from calcium hydroxide. As a result, the water absorbing polymer is present in the friction material while maintaining its water absorbing performance well, the water in the friction surface is effectively absorbed, and the occurrence of the squeal phenomenon can be reliably reduced. .
  • the method of manufacturing the friction material according to the present embodiment includes a mixing step of mixing the friction material raw material and a forming step of molding the mixed friction material raw material into a predetermined shape.
  • the friction material raw material is weighed, and these are uniformly mixed.
  • the friction material raw material is all the materials to be mixed in carrying out the method of manufacturing the friction material according to the present embodiment, and includes the fiber base material, the binder, the organic filler, the inorganic filler and the like described later. .
  • it contains a water absorbing polymer as an organic filler, and contains calcium hydroxide having a function of a pH adjusting material as an inorganic filler.
  • materials generally used in manufacturing friction materials correspond to friction material raw materials.
  • the friction material manufactured by the method of manufacturing a friction material according to the present embodiment is a non-asbestos-based friction material (NAO material). Moreover, it does not substantially contain a copper component with high environmental impact as a friction material raw material (copper free). Specifically, the copper component is not contained, or even when contained, it is 0.5% by weight or less with respect to the entire friction material raw material.
  • the friction material manufactured by the method of manufacturing a friction material according to the present embodiment sufficiently corresponds to the movement of copper freeing.
  • the fiber base can be exemplified by organic fibers, metal fibers, natural or man-made inorganic fibers, and the like.
  • Specific examples of the fiber base include aromatic polyamide fibers (aramid fibers), acrylic fibers, cellulose fibers, carbon fibers and the like as organic fibers, and metal fibers such as steel, stainless steel, aluminum, zinc, And, single metals such as tin, fibers of respective alloy metals, and the like can be mentioned, and as inorganic fibers, rock wool, glass fibers, etc. can be mentioned.
  • the fiber substrate may be used alone or in combination of two or more.
  • the content of the fiber base is not particularly limited, it is preferably contained in an amount of 3 to 15% by weight based on the whole of the friction material raw material.
  • the bonding material has a function of bonding the friction material raw material and gives strength to the friction material.
  • the binder include phenol resin, epoxy resin, melamine resin, and imide resin, and it is also possible to use modified resins such as estramer, hydrocarbon resin, and epoxy. .
  • a binder can also be used individually by 1 type or in combination of multiple types. Although the content of the binder is not particularly limited, it is preferably contained in an amount of 3 to 10% by weight based on the whole of the friction material raw material.
  • the organic filler contains a water absorbing polymer.
  • the water-absorbing polymer is a polymer having a large number of hydrophilic groups in its molecule, and exhibits a three-dimensional network structure by polymerizing monomers and, if necessary, crosslinking them.
  • the hydrophilic group can be exemplified by a carboxy group, a sulfo group, a hydroxy group, an amino group, an amido group, a phosphoric acid group, an ether and the like, and is preferably a proton-dissociated hydrophilic group.
  • polyacrylic acid (salt) type polysulfonic acid (salt) type, maleic anhydride (salt) type, polyaspartic acid (salt) type, polyglutamic acid (salt) type, polyalginic acid (salt) type
  • Starch- and cellulose-based water-absorbing polymers by graft polymerization or carboxymethylation such as polyvinyl alcohol type, polyacrylamide type, polyoxyethylene type, polyethylene imine type, polyvinyl pyrrolidone type, and acrylonitrile, and derivatives thereof
  • the salt is a salt that can be dissociated by the presence of water molecules, preferably a salt with a monovalent ion such as an alkali metal salt.
  • a salt with a monovalent ion such as an alkali metal salt.
  • alkali metal salts of polyacrylic acid such as sodium polyacrylate and potassium polyacrylate
  • polyacrylate-based water absorbent polymers such as ammonium polyacrylate.
  • the water-absorbing polymer is preferably in a water-free state.
  • the property of the water absorbing polymer can be, for example, a solid such as powder, particles, and fibers. From the viewpoint of retention of the water absorption performance of the water absorbent polymer and uniform mixing with other friction material raw materials, it is preferable to use powder form.
  • the substantially water-free powdered water-absorbing polymers have hydrophilic groups that can contribute to their water absorption performance without forming irreversible ionic crosslinks. It becomes easy to remain and can exhibit its water absorption performance effectively.
  • the water-absorbing polymer may or may not be cross-linked with a suitable crosslinker in the polymer backbone.
  • the crosslinking agent is not particularly limited, and any compound known in the art that can be used for crosslinking the water-absorbing polymer can be used, for example, N, N'-methylenebisacrylamide or N, N '.
  • bisacrylamide compounds such as ethylene bis acrylamide
  • diglycidyl ether compounds such as (poly) ethylene glycol diglycidyl ether and (poly) propylene glycol diglycidyl ether
  • dimethacrylate compounds such as ethylene glycol dimethacrylate and the like be able to.
  • crosslinking can be carried out by copolymerizing with a crosslinking monomer.
  • the amount of the crosslinking agent used is also not particularly limited, and can be appropriately set according to the desired crosslinking density.
  • sodium polyacrylate (Toagosei, ARON (registered trademark) A-20P-X: powder type, viscosity 400 to 600 mPa ⁇ s / 30 ° C. (0.2% aqueous solution) ), Molecular weight 5,000,000
  • polyacrylic acid Toagosei, Jurimer (registered trademark): powder type, viscosity 500 to 1000 mPa ⁇ s / 25 ° C. (10% aqueous solution)
  • crosslinked sodium polyacrylate (Leodic (registered trademark)) Powder type, viscosity 1500 to 3000 mPa ⁇ s / 25 ° C. (0.5% aqueous solution), viscosity 7000 to 13000 mPa ⁇ s / 25 ° C. (0.5% aqueous solution), etc.
  • Toagosei, ARON (registered trademark) A-20P-X powder type, viscosity 400 to 600 mPa ⁇ s /
  • the water absorbent polymer has a water absorption performance as high as several hundred times its own weight. Such water absorption performance will be described by taking a salt of a proton dissociative hydrophilic group such as polyacrylate as an example.
  • a salt of a proton dissociative hydrophilic group such as polyacrylate
  • intermolecular chains are tightly intertwined to form a three-dimensional network structure at the time of drying, but water molecules enter inside by capillary action. Due to the presence of the water molecule, the metal ion is dissociated from the salt of the hydrophilic group on the water absorbing polymer molecule, and the hydrophilic group becomes an anion.
  • the hydrophilic groups have the same charge, they are electrically repelled from each other, spread the network structure, and have a structure with many gaps.
  • the ion concentration of the inside of the network structure is increased by the dissociated metal ions, and a difference in ion concentration occurs between the inside and the outside of the water absorbing polymer.
  • an osmotic pressure is generated, water molecules are taken into the inside of the network structure, and the water absorbing polymer is swelled to exhibit high water absorption performance.
  • the water-absorbing polymer is preferably contained in an amount of 0.1 to 4.0% by weight, particularly preferably 0.1 to 3.0% by weight.
  • the content of the water-absorbing polymer exceeds 4.0% by weight, the strength of the friction material is lowered, and the abrasion resistance is unfavorably deteriorated.
  • the content is 3.0% by weight or less, the general efficacy and the wear characteristics become good.
  • the content is less than 0.1% by weight, the water absorption performance of the water-absorbing polymer can not be exhibited.
  • the organic filler can contain cashew dust, rubber powder, tire powder, fluorine polymer and the like in addition to the water absorbing polymer, and one or more of these can be used alone or in combination.
  • the present invention is not limited to the above specific example, and organic fillers known in the art can be preferably used.
  • the content of the organic filler is also not particularly limited, and may be a content generally used in the relevant technical field.
  • the inorganic filler contains calcium hydroxide having a function as a pH adjusting material.
  • Calcium hydroxide is a hydroxide of calcium and is ionized into calcium ions and hydroxide ions which are divalent metal ions, and exhibits strong alkalinity.
  • an inorganic friction modifier in addition to calcium hydroxide, an inorganic friction modifier, titanate, calcium carbonate, magnesium carbonate, barium sulfate, mica, talc, calcium silicate and the like can be contained.
  • titanates include alkali metal titanates and alkali metal titanate / second group salts. Specific examples thereof include potassium titanate, sodium titanate, lithium titanate, lithium potassium titanate, and magnesium titanate. Potassium and the like can be mentioned.
  • the titanate can be contained preferably in an amount of 10 to 30% by weight based on the entire friction material raw material. This makes it possible to compensate for the deterioration of the wear resistance due to the reduction of the copper component.
  • silica such as silicon dioxide, zirconium silicate, zirconium oxide (zirconia), magnesium oxide, aluminum oxide (alumina), chromium oxide (chromium (II) etc.), iron oxide (iron trioxide tetraoxide, etc. Ferric oxide etc., and ceramic powder etc.
  • the inorganic friction modifier is an inorganic substance having a Mohs hardness of 6.5 or more and an average particle diameter of 5 to 250 ⁇ m, preferably 10 to 200 ⁇ m, and is not limited to the above specific example and is preferably an inorganic substance known in the art. Although it can be used, it is preferably zirconium oxide, chromium oxide or aluminum oxide.
  • the content of the inorganic friction modifier is preferably 0.1 to 1.5% by weight, particularly preferably 0.1 to 1.0% by weight, based on the total weight of the friction material.
  • the inorganic friction modifier exceeds 1.0% by weight, the contradiction of the attack on the rotor, which is the opposite material, becomes a problem.
  • adjusting to the said range is preferable.
  • a single metal such as iron, aluminum, zinc or tin and a metal such as a metal powder of each alloy metal can be contained.
  • inorganic fillers may be used alone or in combination of two or more.
  • the content of the inorganic filler is not particularly limited, and may be a content generally used in the relevant technical field.
  • a lubricant can be contained, and specific examples thereof include coke, graphite, carbon black, graphite, metal sulfide and the like.
  • metal sulfides include tin sulfide, antimony trisulfide, molybdenum disulfide, tungsten sulfide and the like.
  • the lubricants may be used alone or in combination of two or more.
  • the content of the lubricant is not particularly limited, and may be a content generally used in the relevant technical field.
  • the mixing method is not particularly limited as long as the friction material can be uniformly mixed, and can be carried out by methods known in the art. It is preferable to mix the friction material in powder form, which facilitates uniform mixing of the friction material.
  • the friction material raw material is preferably mixed in a water-free state or in a very small amount even when water is contained, and in particular, the water-absorbent polymer is mixed in a water-free state to maintain its water absorption performance. It is preferable to do. Therefore, the water content is preferably 1.0% by weight or less with respect to the entire friction material raw material.
  • the mixing method is not particularly limited as long as the friction material raw materials can be uniformly mixed, and can be mixed by methods known in the art. Specifically, mixing can be performed using a mixer such as a Fenshell mixer or a Loedige mixer, and for example, mixing is performed for about 10 minutes at normal temperature. At this time, the mixture of the raw materials for the friction material may be mixed while being cooled by a known cooling method so that the temperature does not rise.
  • a mixer such as a Fenshell mixer or a Loedige mixer
  • the forming step can be performed by pressing the friction material material with a press or the like, and can be performed based on methods known in the relevant technical field.
  • any of a hot press method in which the friction material material is heated, pressed and solidified, and a normal temperature pressing method in which the friction material material is pressed and solidified at normal temperature without heating may be used.
  • the molding temperature is 140 ° C. to 200 ° C. (preferably 160 ° C.)
  • the molding pressure is 10 MPa to 30 MPa (preferably 20 MPa)
  • the molding time is 3 minutes to 15 minutes Preferably, it can be 10 minutes.
  • molding can be performed by setting the molding pressure to 50 MPa to 200 MPa (preferably 100 MPa) and setting the molding time to 5 seconds to 60 seconds (preferably 15 seconds). Subsequently, clamp processing (for example, 180 ° C., 1 MPa, 10 minutes) is performed. After that, heat treatment (preferably 230 ° C., 3 hours) can be performed at 150 ° C. to 250 ° C. for 5 minutes to 180 minutes.
  • a polishing process may be provided to polish the surface of the friction material to form a friction surface.
  • the friction material manufactured by the method of manufacturing the friction material according to the present embodiment can be applied to a disc brake pad for a vehicle etc.
  • the present invention is not limited thereto, and a conventionally known friction material such as a brake shoe can be applied. It can be applied to things.
  • the said friction material can be integrated with plate-shaped members, such as a metal plate as a back plate, for example, and can be used as a pad for brakes.
  • the friction material according to the present embodiment contains a fibrous base material, a binder, an organic filler, and an inorganic filler, and does not contain copper as an element, or the content of copper is zero with respect to the entire friction material. .5% by weight or less, containing a powdery water-absorbing polymer as an organic filler and calcium hydroxide as an inorganic filler.
  • the friction material is manufactured by the method of manufacturing the friction material according to the above-described embodiment. In addition, about the kind of each friction material raw material, and content, it is as having mentioned above.
  • the generation of the squeal phenomenon is suppressed in the high humidity environment by suppressing the increase of the real contact area of the friction material with the mating material at the time of initial braking operation. It can be reduced.
  • the wear powder is taken in because it spreads and spreads within the friction surface between the friction material and the rotor which is the opposite material while taking in some wear powder. It is repeated that copper is discharged from within the friction surface while appropriately roughening the mating material.
  • the presence of the powdery water absorbing polymer efficiently removes the water on the friction surface between the friction material and the mating material, and the aggregation of the wear powder is caused.
  • the increase in the true contact area between the friction material and the mating material can be suppressed.
  • the occurrence of the noise phenomenon at the time of the initial brake operation in a high humidity environment can be effectively reduced.
  • the powdery water-absorbing polymer has good water absorption performance by mixing the powdery water-absorbing polymer as a friction material raw material It will exist in a friction material in the state hold
  • the hydrophilic groups of the water absorbing polymer including the carboxy group are derived from calcium hydroxide or the like of the pH adjusting material contained in the friction material raw material. The formation of irreversible ionic crosslinks with divalent metal ions etc. reduces the water absorption performance.
  • since the water-absorbing polymer in powder form is easily left without forming the ionic crosslinks irreversibly, Water can be absorbed effectively.
  • an inorganic filler having a Mohs hardness of 6.5 or more and an average particle diameter of 10 to 200 ⁇ m is preferably added to the friction material as 0.1.
  • an inorganic filler having a Mohs hardness of 6.5 or more and an average particle diameter of 10 to 200 ⁇ m is preferably added to the friction material as 0.1.
  • Example 1 to 31 and Comparative Examples 1 to 3 the friction material prepared by blending the friction material raw material according to the compounding amount shown in FIGS. 1 and 2 is used as a brake pad, and general efficacy, wear resistance, vibration and brake noise I made an evaluation.
  • the unit of the compounding quantity of each friction material raw material in a figure is weight% with respect to the whole friction material raw material.
  • the average friction number at an initial speed of 50 km / h and 100 km / h of the second efficacy test was evaluated in three stages based on the following criteria. :: Average friction coefficient 0.37 or more and 0.43 or less ⁇ : Average friction coefficient 0.34 or more and less than 0.37, or more than 0.43 and less than 0.46 ⁇ : Average friction coefficient less than 0.34 or 0 More than .46
  • the fade coefficient of friction was evaluated in three stages according to the following criteria. ⁇ : fade coefficient of friction 0.3 or more ⁇ : fade coefficient of friction 0.2 or more and less than 0.3 ⁇ : fade coefficient of friction less than 0.2
  • the friction material of this example contains, in particular, 0.1 to 3.0% by weight of a water absorbing polymer, and an inorganic filler having an average particle diameter of 10 to 200 nm and a Mohs hardness of 6.5 or more and 0.1.
  • a water absorbing polymer contains, in particular, 0.1 to 3.0% by weight of a water absorbing polymer, and an inorganic filler having an average particle diameter of 10 to 200 nm and a Mohs hardness of 6.5 or more and 0.1.
  • ⁇ 1.0% by weight Examples 7 to 17 and 19 to 21
  • Comparative Examples 1 to 3 which do not contain powdery sodium polyacrylate, the occurrence of the squeal was confirmed, and therefore the reduction effect of the squeal phenomenon occurrence confirmed in the present example is the powdery water absorption. It is clear that it is due to the polymer. Further, it was also confirmed that the powdery water-absorbing polymer can exert its effect regardless of the crosslinked and non-crosslinked types.

Abstract

A method for producing a friction material that contains elemental copper in an amount of 0.5% by weight or less relative to the whole friction material. This method for producing a friction material comprises: a mixing step wherein a friction material starting material mixture is obtained by mixing friction material starting materials that include a fiber base material, a binder, an organic filler that contains a powder water absorbent polymer, and an inorganic filler that contains calcium hydroxide; and a molding step wherein the friction material starting material mixture obtained in the mixing step is molded into a predetermined shape.

Description

摩擦材の製造方法及び摩擦材Method of manufacturing friction material and friction material
　本発明は、車両用のブレーキ装置等に使用される摩擦材の製造方法及び摩擦材に関する。 The present invention relates to a method of manufacturing a friction material and a friction material used for a brake device or the like for a vehicle.
　従来から、梅雨期や早朝等の比較的低温で高湿環境下に放置した後に、ブレーキを制動すると、効きが異常に高くなることが知られていた。その結果、ブレーキ時の衝撃が大きくなり、カックンブレーキやブレーキ鳴きを発生したりする。これらの現象は、摩擦材の摩耗粉が水分を吸湿して凝集することにより、摩擦材とロータとの間の真実接触面積を増大させていることに起因する。特に、環境負荷の観点から銅成分の使用を制限する動きが高まる中、銅が有する展延性により摩耗粉を取り混みながらロータ面を適度に粗らして摩耗粉を排出する真実接触面積の低減効果が期待できないので、効きの異常上昇によってブレーキ鳴きが発生し易い。 Heretofore, it has been known that if the brake is braked after being left in a relatively low temperature and high humidity environment such as the rainy season and early morning, the effectiveness becomes abnormally high. As a result, the impact at the time of braking is increased, and a cuckon brake or a brake noise may be generated. These phenomena are due to the fact that the wear powder of the friction material absorbs moisture and condenses, thereby increasing the true contact area between the friction material and the rotor. In particular, while the movement to limit the use of copper components from the viewpoint of environmental load is increasing, the effect of reducing the true contact area where the rotor surface is appropriately roughened and the wear powder is discharged while mixing the wear powder with copper spreadability. Is likely to cause brake noise due to an abnormal rise in effectiveness.
　かかる高湿環境放置後のブレーキ制動時における異常効きや鳴き現象の発生を抑制するための種々の方策が提案されている。例えば、特許文献１には、Ｖ（車速）に対するμ（摩擦係数）の負の勾配（μ－Ｖ負勾配）を低減させれば、低温、高湿環境下に放置後のブレーキ鳴きの発生が低減することが開示されている。詳細には、摩擦材において、研削材として５０％粒子径が０．１～５．０μｍの範囲の酸化ジルコニウムを摩擦材組成物全量に対して１５～３５質量％で含有し、かつ酸化ジルコニウム以外のモース硬度７．０以上の研削材の含有量を摩擦材組成物全量に対して２．０質量％以下としている。その結果、ロータとの擦り合わせ後の摩擦材摺動面が平滑となり、低温、高湿環境下に放置後の一制動中の摩擦材表面とロータの真実接触面積の増大が抑制されるので、μ－Ｖ負勾配が低減され、ブレーキ鳴きが低減すると記載されている。 Various measures have been proposed to suppress the occurrence of abnormal effects and noises during braking during leaving in such a high humidity environment. For example, in Patent Document 1, if the negative gradient (μ-V negative gradient) of μ (friction coefficient) with respect to V (vehicle speed) is reduced, occurrence of brake noise after leaving in a low temperature and high humidity environment It is disclosed to reduce. Specifically, the friction material contains zirconium oxide having a 50% particle diameter in the range of 0.1 to 5.0 μm as an abrasive at 15 to 35% by mass based on the total amount of the friction material composition, and other than zirconium oxide The content of the abrasive having a Mohs hardness of 7.0 or more is 2.0 mass% or less with respect to the total amount of the friction material composition. As a result, the sliding surface of the friction material after rubbing with the rotor becomes smooth, and an increase in the real contact area between the surface of the friction material and the rotor during one braking after being left in a low temperature and high humidity environment is suppressed. It is stated that the μ-V negative slope is reduced and the brake noise is reduced.
　また、特許文献２には、消石灰が熱履歴を受けると生石灰（酸化カルシウム）に変化し、多湿環境下では水分を吸収してクリーム化する特徴を利用し、摩擦材に充填材としての消石灰を多量（少なくとも７～３０体積％）に含有し、且つアルミニウム粒子を少量（２．０～３．５体積％）含有している。その結果、効きの上昇抑制（すなわち、朝効き（ＭＥ）現象の防止）に一定の効果が認められたことが開示されている。 Further, in Patent Document 2, slaked lime is converted to quicklime (calcium oxide) when subjected to a heat history, and utilizes the feature of absorbing moisture to create cream under humid environment, and using slaked lime as a filler in a friction material It contains a large amount (at least 7 to 30% by volume) and contains a small amount (2.0 to 3.5% by volume) of aluminum particles. As a result, it is disclosed that a certain effect is recognized in suppressing the rise of the effect (that is, the prevention of the morning effect (ME) phenomenon).
　特許文献３には、摩擦調整材として親水性活性炭を含有する摩擦材が、硫酸イオンと水分を吸着する機能を有すると記載されている。この親水性活性炭は摩擦材組成物全量に対して０．４～５．０重量％で含有するものであり、その平均粒子径が８０～２００μｍである。また、結合材として親水性フェノール樹脂を摩擦材組成物全量に対して８～１２重量％で含有するものであることが好ましいことが開示されている。当該摩擦材が吸着する硫酸イオンと水分は発錆の要因となるものであり、これによりロータや摩擦材の錆固着を抑制することができると記載されている。 Patent Document 3 describes that a friction material containing hydrophilic activated carbon as a friction modifier has a function of adsorbing sulfate ion and water. The hydrophilic activated carbon is contained in an amount of 0.4 to 5.0% by weight based on the total amount of the friction material composition, and the average particle diameter thereof is 80 to 200 μm. Further, it is disclosed that it is preferable to use a hydrophilic phenolic resin as a binder at 8 to 12% by weight with respect to the total amount of the friction material composition. It is described that the sulfate ion and the moisture adsorbed by the friction material cause the rusting, which can suppress the rusting of the rotor and the friction material.
特開２０１０－２４４２９号公報JP, 2010-24429, A 特開２００７－８４６４３号公報JP 2007-84643 A 特開２０１４－１２７６６号公報JP, 2014-12766, A
　しかしながら、特許文献１で開示された技術は、摩擦材において酸化ジルコニウムの含有量が１５～３５質量％と多量であることから、ロータへの攻撃性が高く、ロータの摩耗及びＤＴＶ（disk　thickness　variation、ディスク厚偏差）成長によるブレーキ振動（シャダー）の悪化が想定される。特許文献２で開示された技術は、消石灰を多量に含有するため、フェノール樹脂等の結合材のフロー阻害顕著となり、摩擦材の強度の低下が想定される。特許文献３で開示された技術は、活性炭を用いているので、高湿度環境下における水分の吸着や、結露した水分等の液状の水分の吸着が不十分となり、ブレーキ鳴き現象の発生を効果的に抑制できないことが想定される。 However, the technology disclosed in Patent Document 1 is highly aggressive to the rotor because the content of zirconium oxide in the friction material is as large as 15 to 35% by mass, and the wear of the rotor and disk thickness variation The deterioration of the brake vibration (shudder) due to the growth of the disc thickness deviation) is assumed. Since the technique disclosed in Patent Document 2 contains a large amount of slaked lime, the flow inhibition of a binder such as a phenol resin becomes remarkable, and a decrease in the strength of the friction material is assumed. Since the technology disclosed in Patent Document 3 uses activated carbon, the adsorption of water in a high humidity environment and the adsorption of liquid water such as condensed water become insufficient, and the occurrence of a brake noise phenomenon is effective. It is assumed that it can not be suppressed.
　そこで、本発明は、高湿環境下において鳴き現象の発生を効果的に低減することができる摩擦材の製造方法及び摩擦材を提供することを課題とする。 Then, this invention makes it a subject to provide the manufacturing method and friction material of a friction material which can reduce generation | occurrence | production of a squeal phenomenon effectively in high-humidity environment.
　本発明者らは、上記課題を解決するため鋭意研究を行い、摩擦材の製造時に粉体状の吸水性ポリマーを含有させることにより、高湿度環境下に放置後のブレーキ制動時における水分の影響を最小限に抑えられることに着目した。その結果、摩耗粉同士の凝集が抑制され、摩擦材の相手材であるロータとの真実接触面積の増大を抑制し、鳴き現象の発生を低減することができることを見出した。また、無機充填材としてモース硬度が６．５以上で特定の平均粒子径を有する無機物を所定量含有させることにより、相手材に対する適度な面粗し効果が得られ、効果的に摩耗粉を排出することができることも見出した。これにより、摩擦材の相手材との真実接触面積の増大を抑制による鳴き現象の発生を更に効果的に低減することができることを見出し、本発明を完成させるに至った。 The inventors of the present invention conducted intensive studies to solve the above-mentioned problems, and by incorporating a powdery water-absorbing polymer at the time of production of the friction material, the influence of moisture at the time of braking after leaving in a high humidity environment. We focused on being able to minimize As a result, it has been found that the aggregation of the wear powder is suppressed, the increase in the true contact area with the rotor which is the opposite material of the friction material can be suppressed, and the occurrence of the squeal phenomenon can be reduced. In addition, by incorporating a predetermined amount of inorganic material having a specific average particle diameter and a Mohs hardness of 6.5 or more as an inorganic filler, an appropriate surface roughening effect on the other material is obtained, and wear powder is effectively discharged. I also found that I can do it. As a result, it has been found that the occurrence of the squeal phenomenon can be further effectively reduced by suppressing the increase in the real contact area of the friction material with the other material, and the present invention has been completed.
　即ち、摩擦材の製造方法及び摩擦材は、以下の〔１〕及び〔２〕に関する。〔１〕元素として銅の含有量が摩擦材全体に対して０．５重量％以下である摩擦材の製造方法であって、
　繊維基材、結合材、粉体状の吸水性ポリマーを含有する有機充填材、及び、水酸化カルシウムを含有する無機充填材を含む摩擦材原料を混合して摩擦材原料混合物を得る混合工程と、
　前記混合工程で得られた前記摩擦材原料混合物を所定の形状に成形する成形工程と、を含む摩擦材の製造方法。 That is, the method of manufacturing the friction material and the friction material relate to the following [1] and [2]. [1] A method of manufacturing a friction material, wherein the content of copper as an element is 0.5% by weight or less based on the entire friction material,
A mixing step of mixing a friction material material containing a fibrous base material, a binder, an organic filler containing a powdery water-absorbing polymer, and an inorganic filler containing calcium hydroxide to obtain a friction material mixture ,
Forming the friction material raw material mixture obtained in the mixing step into a predetermined shape.
　上記〔１〕の方法で製造された摩擦材は、高湿環境下において、初期ブレーキ操作時の鳴き現象の発生を低減することができる。これは、吸水性ポリマーの存在により、摩擦材と相手材であるロータとの摩擦面における水分が効率よく除去されて摩耗粉同士の凝集が抑制され、摩擦材と相手材との真実接触面積の増大を抑制することができるからである。更に、粉体状の吸水性ポリマーを摩擦材原料として混合することで、この吸水性ポリマーが水酸化カルシウムに由来する二価金属イオンと不可逆的なイオン架橋を形成することなく残存し易くなる。その結果、吸水性ポリマーはその吸水性能を良好に保持した状態で摩擦材中に存在することとなり、摩擦面内の水分が効果的に吸収され、鳴き現象の発生を確実に低減させることができる。 The friction material manufactured by the method of the above [1] can reduce the occurrence of the noise phenomenon at the time of initial brake operation in a high humidity environment. This is because the presence of the water absorbing polymer efficiently removes the water on the friction surface of the friction material and the rotor as the counterpart material, thereby suppressing the aggregation of the wear powder, and the true contact area between the friction material and the counterpart material. This is because the increase can be suppressed. Furthermore, by mixing a powdery water-absorbing polymer as a raw material of the friction material, the water-absorbing polymer easily remains without forming an irreversible ionic cross-link with a divalent metal ion derived from calcium hydroxide. As a result, the water absorbing polymer is present in the friction material while maintaining its water absorbing performance well, the water in the friction surface is effectively absorbed, and the occurrence of the squeal phenomenon can be reliably reduced. .
　〔２〕繊維基材、結合材、有機充填材、及び、無機充填材を含有し、
　元素として銅の含有量が摩擦材全体に対して０．５重量％以下であり、前記有機充填材として粉体状の吸水性ポリマーを含有し、前記無機充填材として水酸化カルシウムを含有する摩擦材。 [2] A fibrous base material, a binder, an organic filler, and an inorganic filler, and
The friction is such that the content of copper as an element is 0.5% by weight or less with respect to the entire friction material, contains a powdery water-absorbing polymer as the organic filler, and contains calcium hydroxide as the inorganic filler. Material.
　上記〔２〕の摩擦材によれば、高湿環境下において、初期ブレーキ操作時の摩擦材の相手材との真実接触面積の増大を抑制して、鳴き現象の発生を低減することができる。 According to the friction material of the above [2], in a high humidity environment, it is possible to suppress an increase in the real contact area of the friction material with the counterpart material at the time of initial brake operation, and reduce the occurrence of the squeal phenomenon.
本実施形態に係る摩擦材の実施例の摩擦材原料の配合組成とその性能評価を要約した図である。It is the figure which summarized the composition of the friction material raw material of the example of the friction material concerning this embodiment, and its performance evaluation. 本実施形態に係る摩擦材の実施例及び比較例の摩擦材原料の配合組成とその性能評価を要約した図である。It is the figure which summarized the composition of the friction material raw material of the example of a friction material concerning this embodiment, and a comparative example, and its performance evaluation.
　以下、本発明を実施するための形態を説明する。ただし、本実施形態は本発明を具体的に説明するための例示に過ぎず、したがって、本発明は以下の実施形態に限定されるものではない。 Hereinafter, modes for carrying out the present invention will be described. However, the present embodiment is merely an example for specifically describing the present invention, and accordingly, the present invention is not limited to the following embodiment.
（摩擦材の製造方法）
　本実施形態に係る摩擦材の製造方法は、摩擦材原料を混合する混合工程と、混合された摩擦材原料を所定の形状に成形する成形工程とを備えている。 (Method of manufacturing friction material)
The method of manufacturing the friction material according to the present embodiment includes a mixing step of mixing the friction material raw material and a forming step of molding the mixed friction material raw material into a predetermined shape.
　本実施形態に係る摩擦材の製造方法は、混合工程において、摩擦材原料を秤量し、これらを均一に混合する。摩擦材原料は、本実施形態に係る摩擦材の製造方法を実施する上で混合する全ての材料であり、後述する繊維基材、結合材、有機充填材、及び無機充填材等が含有される。特に、有機充填材として吸水性ポリマーを含有し、無機充填材としてｐＨ調整材の機能を有する水酸化カルシウムを含有する。更に、これらの他にも摩擦材を製造する際に一般に使用される材料が摩擦材原料に該当する。 In the method of manufacturing the friction material according to the present embodiment, in the mixing step, the friction material raw material is weighed, and these are uniformly mixed. The friction material raw material is all the materials to be mixed in carrying out the method of manufacturing the friction material according to the present embodiment, and includes the fiber base material, the binder, the organic filler, the inorganic filler and the like described later. . In particular, it contains a water absorbing polymer as an organic filler, and contains calcium hydroxide having a function of a pH adjusting material as an inorganic filler. Furthermore, in addition to these, materials generally used in manufacturing friction materials correspond to friction material raw materials.
　本実施形態に係る摩擦材の製造方法で製造される摩擦材は、非石綿系摩擦材（ＮＡＯ材）である。また、摩擦材原料として環境負荷の高い銅成分を実質的に含有するものではない（銅フリー化）。具体的には、銅成分は含有しないか、含有する場合であっても摩擦材原料全体に対して０．５重量％以下である。本実施形態に係る摩擦材の製造方法で製造される摩擦材は、銅フリー化の動きに十分に対応するものである。 The friction material manufactured by the method of manufacturing a friction material according to the present embodiment is a non-asbestos-based friction material (NAO material). Moreover, it does not substantially contain a copper component with high environmental impact as a friction material raw material (copper free). Specifically, the copper component is not contained, or even when contained, it is 0.5% by weight or less with respect to the entire friction material raw material. The friction material manufactured by the method of manufacturing a friction material according to the present embodiment sufficiently corresponds to the movement of copper freeing.
　繊維基材は、有機繊維や金属繊維、天然又は人造の無機繊維等を例示することができる。繊維基材の具体例は、有機繊維としては芳香族ポリアミド繊維（アラミド繊維）、アクリル繊維、セルロース繊維、及び、炭素繊維等を挙げることができ、金属繊維としてはスチール、ステンレス、アルミ、亜鉛、及び、スズ等の単独金属、並びに、それぞれの合金金属の繊維等を挙げることができ、無機繊維としてはロックウール、及び、ガラス繊維等を挙げることができる。繊維基材は、１種類を単独で、又は、複数種類を併用することもできる。また、繊維基材の含有量は特に制限されるものではないが、摩擦材原料全体に対して、好ましくは３～１５重量％で含有する。 The fiber base can be exemplified by organic fibers, metal fibers, natural or man-made inorganic fibers, and the like. Specific examples of the fiber base include aromatic polyamide fibers (aramid fibers), acrylic fibers, cellulose fibers, carbon fibers and the like as organic fibers, and metal fibers such as steel, stainless steel, aluminum, zinc, And, single metals such as tin, fibers of respective alloy metals, and the like can be mentioned, and as inorganic fibers, rock wool, glass fibers, etc. can be mentioned. The fiber substrate may be used alone or in combination of two or more. Although the content of the fiber base is not particularly limited, it is preferably contained in an amount of 3 to 15% by weight based on the whole of the friction material raw material.
　結合材は、摩擦材原料を結合させる機能を有し、摩擦材に強度を与えるものである。結合材の具体例としては、フェノール樹脂、エポキシ樹脂、メラミン樹脂、及び、イミド樹脂等を挙げることができ、それぞれのエストラマー、炭化水素樹脂、及び、エポキシ等の変性した樹脂を使用することもできる。結合材は、１種類を単独で、又は、複数種類を併用することもできる。また、結合材の含有量は特に制限されるものではないが、摩擦材原料全体に対して、好ましくは３～１０重量％で含有する。 The bonding material has a function of bonding the friction material raw material and gives strength to the friction material. Specific examples of the binder include phenol resin, epoxy resin, melamine resin, and imide resin, and it is also possible to use modified resins such as estramer, hydrocarbon resin, and epoxy. . A binder can also be used individually by 1 type or in combination of multiple types. Although the content of the binder is not particularly limited, it is preferably contained in an amount of 3 to 10% by weight based on the whole of the friction material raw material.
　有機充填材は、吸水性ポリマーを含有する。ここで、吸水性ポリマーは、その分子内に多数の親水基を有したポリマーであり、モノマーを重合、及び、必要に応じて架橋することにより三次元の網目構造を示す。親水基は、カルボキシ基、スルホ基、ヒドロキシ基、アミノ基、アミド基、リン酸基、及びエーテル等が例示でき、好ましくは、プロトン解離型の親水基である。 The organic filler contains a water absorbing polymer. Here, the water-absorbing polymer is a polymer having a large number of hydrophilic groups in its molecule, and exhibits a three-dimensional network structure by polymerizing monomers and, if necessary, crosslinking them. The hydrophilic group can be exemplified by a carboxy group, a sulfo group, a hydroxy group, an amino group, an amido group, a phosphoric acid group, an ether and the like, and is preferably a proton-dissociated hydrophilic group.
　吸水性ポリマーとしては、ポリアクリル酸（塩）系、ポリスルホン酸（塩）系、無水マレイン酸（塩）系、ポリアスパラギン酸（塩）系、ポリグルタミン酸（塩）系、ポリアルギン酸（塩）系、ポリビニルアルコール系、ポリアクリルアミド系、ポリオキシエチレン系、ポリエチレンイミン系、ポリビニルピロリドン系、及び、アクリロニトリル等のグラフト重合若しくはカルボキシメチル化によるデンプン系及びセルロース系の吸水性ポリマー、並びに、これらの誘導体を例示できるが、これらに限定するものではなく、公知の吸水性ポリマーを使用することができる。ここで、塩は水分子の存在により解離可能な塩であり、好ましくはアルカリ金属塩等の一価イオンとの塩が好ましい。特に好ましくは、ポリアクリル酸ナトリウムやポリアクリル酸カリウム等のポリアクリル酸のアルカリ金属塩、及び、ポリアクリル酸アンモニウム等のポリアクリル酸塩系の吸水性ポリマーである。 As a water absorbing polymer, polyacrylic acid (salt) type, polysulfonic acid (salt) type, maleic anhydride (salt) type, polyaspartic acid (salt) type, polyglutamic acid (salt) type, polyalginic acid (salt) type Starch- and cellulose-based water-absorbing polymers by graft polymerization or carboxymethylation such as polyvinyl alcohol type, polyacrylamide type, polyoxyethylene type, polyethylene imine type, polyvinyl pyrrolidone type, and acrylonitrile, and derivatives thereof Although it can illustrate, it does not limit to these and a well-known water-absorbing polymer can be used. Here, the salt is a salt that can be dissociated by the presence of water molecules, preferably a salt with a monovalent ion such as an alkali metal salt. Particularly preferred are alkali metal salts of polyacrylic acid such as sodium polyacrylate and potassium polyacrylate, and polyacrylate-based water absorbent polymers such as ammonium polyacrylate.
　吸水性ポリマーは、好ましくは水を含まない状態であることが好ましい。吸水性ポリマーの性状は、例えば、粉体状、粒子状、及び繊維状等の固体とすることができる。吸水性ポリマーの吸水性能の保持、及び、他の摩擦材原料との均一な混合の観点から、粉体状とすることが好ましい。実質的に水分を含まない粉体状の吸水性ポリマーは、水溶液状又はエマルジョン状態の吸水性ポリマーに比べて、その吸水性能に貢献し得る親水基が、不可逆的なイオン架橋を形成せずに残存しやすくなり、その吸水性能を効果的に発揮することができる。 The water-absorbing polymer is preferably in a water-free state. The property of the water absorbing polymer can be, for example, a solid such as powder, particles, and fibers. From the viewpoint of retention of the water absorption performance of the water absorbent polymer and uniform mixing with other friction material raw materials, it is preferable to use powder form. Compared with water-absorbing polymers in the form of an aqueous solution or an emulsion, the substantially water-free powdered water-absorbing polymers have hydrophilic groups that can contribute to their water absorption performance without forming irreversible ionic crosslinks. It becomes easy to remain and can exhibit its water absorption performance effectively.
　吸水性ポリマーは、ポリマー主鎖が適当な架橋剤で架橋されていても、架橋されていなくてもよい。架橋剤としては特に制限はなく、吸水性ポリマーの架橋のために使用できる当該技術分野で公知の化合物を何れも使用することができ、例えば、Ｎ，Ｎ´－メチレンビスアクリルアミドやＮ，Ｎ´－エチレンビスアクリルアミド等のビスアクリルアミド系化合物、（ポリ）エチレングリコールジグリシジルエーテルや（ポリ）プロピレングリコールジグリシジルエーテル等のジグリシジルエーテル系化合物、エチレングリコールジメタクリレート等のジメタクリレート系化合物等を使用することができる。例えば、架橋性モノマーと共重合することによって架橋を行うことができる。架橋剤の使用量についても特に制限はなく、所望の架橋密度に応じて適宜設定することができる。 The water-absorbing polymer may or may not be cross-linked with a suitable crosslinker in the polymer backbone. The crosslinking agent is not particularly limited, and any compound known in the art that can be used for crosslinking the water-absorbing polymer can be used, for example, N, N'-methylenebisacrylamide or N, N '. -Using bisacrylamide compounds such as ethylene bis acrylamide, diglycidyl ether compounds such as (poly) ethylene glycol diglycidyl ether and (poly) propylene glycol diglycidyl ether, and dimethacrylate compounds such as ethylene glycol dimethacrylate and the like be able to. For example, crosslinking can be carried out by copolymerizing with a crosslinking monomer. The amount of the crosslinking agent used is also not particularly limited, and can be appropriately set according to the desired crosslinking density.
　市販品も好適に使用でき、具体的には、ポリアクリル酸ナトリウム（東亜合成、アロン（登録商標）Ａ－２０Ｐ－Ｘ：粉末タイプ、粘度４００～６００ｍＰａ・ｓ／３０℃（０．２％水溶液）、分子量５００万）、ポリアクリル酸（東亜合成、ジュリマー（登録商標）：粉末タイプ、粘度５００～１０００ｍＰａ・ｓ／２５℃（１０％水溶液））、架橋ポリアクリル酸ナトリウム（レオジック（登録商標）：粉末タイプ、粘度１５００～３０００ｍＰａ・ｓ／２５℃（０．５％水溶液）、又は、粘度７０００～１３０００ｍＰａ・ｓ／２５℃（０．５％水溶液））等を使用することができる。 Commercially available products can also be suitably used. Specifically, sodium polyacrylate (Toagosei, ARON (registered trademark) A-20P-X: powder type, viscosity 400 to 600 mPa · s / 30 ° C. (0.2% aqueous solution) ), Molecular weight 5,000,000), polyacrylic acid (Toagosei, Jurimer (registered trademark): powder type, viscosity 500 to 1000 mPa · s / 25 ° C. (10% aqueous solution)), crosslinked sodium polyacrylate (Leodic (registered trademark)) Powder type, viscosity 1500 to 3000 mPa · s / 25 ° C. (0.5% aqueous solution), viscosity 7000 to 13000 mPa · s / 25 ° C. (0.5% aqueous solution), etc. can be used.
　吸水性ポリマーは、自重の数百倍の高い吸水性能を有する。かかる吸水性能を、ポリアクリル酸塩等のプロトン解離性の親水基の塩を例にとって説明する。吸水性ポリマーは、乾燥時において分子間鎖が密に絡みあい三次元の網目構造を形成しているが、毛細管現象で内部に水分子が入り込む。水分子の存在により、吸水性ポリマー分子上の親水基の塩から金属イオンが解離し、親水基はアニオンとなる。すると、親水基同士が、同じ電荷を有することから電気的に反発し網目構造を広げ隙間の多い構造をとる。網目構造の内部は解離した金属イオンによりイオン濃度が上昇し、吸水性ポリマー内外でイオン濃度差が生じる。これにより、浸透圧が生じ、網目構造内部に水分子が取り込まれ吸水性ポリマーが膨潤され、高い吸水性能を発揮する。 The water absorbent polymer has a water absorption performance as high as several hundred times its own weight. Such water absorption performance will be described by taking a salt of a proton dissociative hydrophilic group such as polyacrylate as an example. In the water-absorbent polymer, intermolecular chains are tightly intertwined to form a three-dimensional network structure at the time of drying, but water molecules enter inside by capillary action. Due to the presence of the water molecule, the metal ion is dissociated from the salt of the hydrophilic group on the water absorbing polymer molecule, and the hydrophilic group becomes an anion. Then, since the hydrophilic groups have the same charge, they are electrically repelled from each other, spread the network structure, and have a structure with many gaps. The ion concentration of the inside of the network structure is increased by the dissociated metal ions, and a difference in ion concentration occurs between the inside and the outside of the water absorbing polymer. As a result, an osmotic pressure is generated, water molecules are taken into the inside of the network structure, and the water absorbing polymer is swelled to exhibit high water absorption performance.
　吸水性ポリマーは、好ましくは０．１～４．０重量％、特に好ましくは０．１～３．０重量％で含有させる。吸水性ポリマーの含有量は４．０重量％を超えると摩擦材の強度が低下し、耐摩耗性が悪化するため好ましくない。特に、３．０重量％以下であると、一般効力や摩耗特性が良好となる。一方、０．１重量％より少なくなると、吸水性ポリマーの吸水性能を発揮することができないことから、上記範囲で含有することが好ましい。 The water-absorbing polymer is preferably contained in an amount of 0.1 to 4.0% by weight, particularly preferably 0.1 to 3.0% by weight. When the content of the water-absorbing polymer exceeds 4.0% by weight, the strength of the friction material is lowered, and the abrasion resistance is unfavorably deteriorated. In particular, when the content is 3.0% by weight or less, the general efficacy and the wear characteristics become good. On the other hand, if the content is less than 0.1% by weight, the water absorption performance of the water-absorbing polymer can not be exhibited.
　有機充填材は、吸水性ポリマーの他に、カシューダスト、ゴム粉、タイヤ粉、及び、フッ素ポリマー等を含有させることができ、これらを１種類単独で、又は、複数種類を併用することもできる。しかしながら、上記具体例に限定するものではなく、当該技術分野で公知の有機充填材を好ましく使用することができる。有機充填材の含有量も特に制限はなく、当該技術分野で通常使われる含有量とすることができる。 The organic filler can contain cashew dust, rubber powder, tire powder, fluorine polymer and the like in addition to the water absorbing polymer, and one or more of these can be used alone or in combination. . However, the present invention is not limited to the above specific example, and organic fillers known in the art can be preferably used. The content of the organic filler is also not particularly limited, and may be a content generally used in the relevant technical field.
　無機充填材は、ｐＨ調整材としての機能を有する水酸化カルシウムを含有する。水酸化カルシウムはカルシウムの水酸化物であり、二価金属イオンであるカルシウムイオンと水酸化物イオンに電離し、強アルカリ性を示す。 The inorganic filler contains calcium hydroxide having a function as a pH adjusting material. Calcium hydroxide is a hydroxide of calcium and is ionized into calcium ions and hydroxide ions which are divalent metal ions, and exhibits strong alkalinity.
　無機充填材としては、水酸化カルシウムの他に、無機摩擦調整材、チタン酸塩、炭酸カルシウム、炭酸マグネシウム、硫酸バリウム、マイカ、タルク、及び、ケイ酸カルシウム等を含有させることができる。チタン酸塩は、チタン酸アルカリ金属塩、チタン酸アルカリ金属・第二族塩等が例示でき、具体例としては、チタン酸カリウム、チタン酸ナトリウム、チタン酸リチウム、チタン酸リチウムカリウム、チタン酸マグネシウムカリウム等を挙げることができる。チタン酸塩は、摩擦材原料全体に対して好ましくは１０～３０重量％で含有することができる。これにより、銅成分の削減による耐摩耗性悪化を補填することができる。 As the inorganic filler, in addition to calcium hydroxide, an inorganic friction modifier, titanate, calcium carbonate, magnesium carbonate, barium sulfate, mica, talc, calcium silicate and the like can be contained. Examples of titanates include alkali metal titanates and alkali metal titanate / second group salts. Specific examples thereof include potassium titanate, sodium titanate, lithium titanate, lithium potassium titanate, and magnesium titanate. Potassium and the like can be mentioned. The titanate can be contained preferably in an amount of 10 to 30% by weight based on the entire friction material raw material. This makes it possible to compensate for the deterioration of the wear resistance due to the reduction of the copper component.
　無機摩擦調整材として、二酸化ケイ素等のシリカ、ケイ酸ジルコニウム、酸化ジルコニウム（ジルコニア）、酸化マグネシウム、酸化アルミニウム（アルミナ）、酸化クロム（酸化クロム（ＩＩ）等）、酸化鉄（四三酸化鉄や酸化第二鉄等）、及び、セラミック粉等を含有することができる。無機摩擦調整材は、モース硬度６．５以上で平均粒子径が５～２５０μｍ、好ましくは１０～２００μｍの無機物であり、上記の具体例に限定されることなく当該技術分野で公知の無機物を好ましく使用することができるが、好ましくは、酸化ジルコニウム、酸化クロム、又は酸化アルミニウムである。ここで、無機摩擦調整材の粒子径は２００μｍを超えると相手材であるロータへの攻撃の背反が問題となる。一方、１０μｍより小さくなると摩擦調整効果を得難いことから、上記範囲に調整することが好ましい。同様に無機摩擦調整材の含有量についても、摩擦材原料全体に対して、０．１～１．５重量％が好ましく、０．１～１．０重量％とすることが特に好ましい。ここで、無機摩擦調整材が１．０重量％を超えると相手材であるロータへの攻撃の背反が問題となる。一方、０．１重量％より小さくなると摩擦調整効果を得難いことから、上記範囲に調整することが好ましい。 As inorganic friction modifiers, silica such as silicon dioxide, zirconium silicate, zirconium oxide (zirconia), magnesium oxide, aluminum oxide (alumina), chromium oxide (chromium (II) etc.), iron oxide (iron trioxide tetraoxide, etc. Ferric oxide etc., and ceramic powder etc. can be contained. The inorganic friction modifier is an inorganic substance having a Mohs hardness of 6.5 or more and an average particle diameter of 5 to 250 μm, preferably 10 to 200 μm, and is not limited to the above specific example and is preferably an inorganic substance known in the art. Although it can be used, it is preferably zirconium oxide, chromium oxide or aluminum oxide. Here, when the particle diameter of the inorganic friction modifier exceeds 200 μm, the contradiction of the attack on the rotor, which is the opposite material, becomes a problem. On the other hand, since it will be difficult to acquire a friction adjustment effect if it becomes smaller than 10 micrometers, adjusting to the said range is preferable. Similarly, the content of the inorganic friction modifier is preferably 0.1 to 1.5% by weight, particularly preferably 0.1 to 1.0% by weight, based on the total weight of the friction material. Here, when the inorganic friction modifier exceeds 1.0% by weight, the contradiction of the attack on the rotor, which is the opposite material, becomes a problem. On the other hand, since it will be difficult to acquire a friction adjustment effect if it becomes smaller than 0.1 weight%, adjusting to the said range is preferable.
　鉄、アルミ、亜鉛、スズ等の単独金属、並びに、それぞれの合金金属による金属粉等の金属を含有させることができる。 A single metal such as iron, aluminum, zinc or tin and a metal such as a metal powder of each alloy metal can be contained.
　これら無機充填材は、１種類を単独で、又は、複数種類を併用することもできる。無機充填材の含有量は特に制限はなく、当該技術分野で通常使われる含有量とすることができる。 These inorganic fillers may be used alone or in combination of two or more. The content of the inorganic filler is not particularly limited, and may be a content generally used in the relevant technical field.
　摩擦材原料としては、潤滑材を含有することができ、具体例としては、コークス、黒鉛、カーボンブラック、グラファイト、及び金属硫化物等を挙げることができる。金属硫化物は、硫化スズ、三硫化アンチモン、二硫化モリブテン、硫化タングステン等が例示できる。潤滑材は、１種類を単独で、又は、複数種類を併用することもできる。潤滑材の含有量は特に制限はなく、当該技術分野で通常使われる含有量とすることができる。 As the friction material raw material, a lubricant can be contained, and specific examples thereof include coke, graphite, carbon black, graphite, metal sulfide and the like. Examples of metal sulfides include tin sulfide, antimony trisulfide, molybdenum disulfide, tungsten sulfide and the like. The lubricants may be used alone or in combination of two or more. The content of the lubricant is not particularly limited, and may be a content generally used in the relevant technical field.
　混合方法は、摩擦材原料を均一に混合できる限り特に制限はなく、当該技術分野で公知の方法により行うことができる。摩擦材原料を粉体状で混合することが好ましく、これにより摩擦材原料を均一に混合することが容易となる。摩擦材原料は水分を含まない状態で、又は、水分が含まれる場合にも極微量の状態で混合することが好ましく、特に、吸水性ポリマーはその吸水性能保持のため水分を含まない状態で混合することが好ましい。したがって、水分量は摩擦材原料全体に対して１．０重量％以下とすることが好ましい。 The mixing method is not particularly limited as long as the friction material can be uniformly mixed, and can be carried out by methods known in the art. It is preferable to mix the friction material in powder form, which facilitates uniform mixing of the friction material. The friction material raw material is preferably mixed in a water-free state or in a very small amount even when water is contained, and in particular, the water-absorbent polymer is mixed in a water-free state to maintain its water absorption performance. It is preferable to do. Therefore, the water content is preferably 1.0% by weight or less with respect to the entire friction material raw material.
　混合方法としては、摩擦材原料を均一に混合できる限り特に制限はなく、当該技術分野で公知の方法により混合することができる。具体的には、フェンシェルミキサやレディーゲミキサ等の混合機を使用して混合することができ、例えば、常温で１０分程度混合する。このとき、摩擦材原料の混合物が昇温しないように公知の冷却方法によって冷却しながら混合するようにしてもよい。 The mixing method is not particularly limited as long as the friction material raw materials can be uniformly mixed, and can be mixed by methods known in the art. Specifically, mixing can be performed using a mixer such as a Fenshell mixer or a Loedige mixer, and for example, mixing is performed for about 10 minutes at normal temperature. At this time, the mixture of the raw materials for the friction material may be mixed while being cooled by a known cooling method so that the temperature does not rise.
　成形工程は、摩擦材原料をプレス等で押し固めることにより行うことができ、当該技術分野で公知の方法に基づいて行うことができる。プレスによる成形に際しては、摩擦材原料を加熱して押し固めて成形するホットプレス工法と、摩擦材原料を加熱せずに常温で押し固めて成形する常温プレス工法の何れで行ってもよい。ホットプレス工法で成形する場合には、例えば、成形温度を１４０℃～２００℃（好ましくは１６０℃）とし、成形圧力を１０ＭＰａ～３０ＭＰａ（好ましくは２０ＭＰａ）とし、成形時間を３分～１５分（好ましくは１０分）とすることができる。常温プレス工法で成形する場合には、例えば、成形圧力を５０ＭＰａ～２００ＭＰａ（好ましくは１００ＭＰａ）とし、成形時間を５秒～６０秒（好ましくは１５秒）とすることで成形することができる。続いて、クランプ処理（例えば、１８０℃、１ＭＰａ、１０分）を行う。その後、１５０℃～２５０℃、５分～１８０分の熱処理（好ましくは、２３０℃、３時間）を行うことができる。 The forming step can be performed by pressing the friction material material with a press or the like, and can be performed based on methods known in the relevant technical field. In the case of molding by pressing, any of a hot press method in which the friction material material is heated, pressed and solidified, and a normal temperature pressing method in which the friction material material is pressed and solidified at normal temperature without heating may be used. In the case of molding by the hot press method, for example, the molding temperature is 140 ° C. to 200 ° C. (preferably 160 ° C.), the molding pressure is 10 MPa to 30 MPa (preferably 20 MPa), and the molding time is 3 minutes to 15 minutes Preferably, it can be 10 minutes. In the case of molding by the normal temperature press method, for example, molding can be performed by setting the molding pressure to 50 MPa to 200 MPa (preferably 100 MPa) and setting the molding time to 5 seconds to 60 seconds (preferably 15 seconds). Subsequently, clamp processing (for example, 180 ° C., 1 MPa, 10 minutes) is performed. After that, heat treatment (preferably 230 ° C., 3 hours) can be performed at 150 ° C. to 250 ° C. for 5 minutes to 180 minutes.
　更に、必要に応じて、摩擦材の表面を研磨し摩擦面を形成する研磨工程を設けてもよい。 Furthermore, if necessary, a polishing process may be provided to polish the surface of the friction material to form a friction surface.
　本実施形態に係る摩擦材の製造方法で製造される摩擦材は、車両等のディスクブレーキ用パッドに適用できるが、これに限られるものではなく、ブレーキシュー等、従来公知の摩擦材が適用できるものに適用することができる。当該摩擦材は、例えば、裏板としての金属板等の板状部材と一体化してブレーキ用パッドとして使用することができる。 Although the friction material manufactured by the method of manufacturing the friction material according to the present embodiment can be applied to a disc brake pad for a vehicle etc., the present invention is not limited thereto, and a conventionally known friction material such as a brake shoe can be applied. It can be applied to things. The said friction material can be integrated with plate-shaped members, such as a metal plate as a back plate, for example, and can be used as a pad for brakes.
（摩擦材）
　本実施形態に係る摩擦材は、繊維基材、結合材、有機充填材、及び、無機充填材を含有し、元素として銅を含有しない、又は、銅の含有量が摩擦材全体に対して０．５重量％以下であり、有機充填材として粉体状の吸水性ポリマーを、無機充填材として水酸化カルシウムを含有するものである。この摩擦材は、上記した実施形態に係る摩擦材の製造方法により製造されるものである。なお、各摩擦材原料の種類、及び、含有量については上記した通りである。 (Friction material)
The friction material according to the present embodiment contains a fibrous base material, a binder, an organic filler, and an inorganic filler, and does not contain copper as an element, or the content of copper is zero with respect to the entire friction material. .5% by weight or less, containing a powdery water-absorbing polymer as an organic filler and calcium hydroxide as an inorganic filler. The friction material is manufactured by the method of manufacturing the friction material according to the above-described embodiment. In addition, about the kind of each friction material raw material, and content, it is as having mentioned above.
（作用効果）
　本実施形態に係る摩擦材の製造方法及び摩擦材によれば、高湿環境下において、初期ブレーキ操作時の摩擦材の相手材との真実接触面積の増大を抑制して、鳴き現象の発生を低減することができる。銅を含有する従来の摩擦材においては、銅がもつ展延性により、一部の摩耗粉を取り込みながら摩擦材と相手材であるロータとの摩擦面内で延び広がることから、摩耗粉を取り込んだ銅が相手材を適度に面粗ししながら摩擦面内から排出されることを繰り返す。これにより、摩擦材と相手材との真実接触面積を増大することなく、摩擦係数の上昇による異常効きや鳴き現象の発生を抑制していた。しかしながら、高湿度環境下に放置されると、摩耗粉が水分を吸湿し凝集することから、上記銅による面粗し作用のみでは真実接触面積の抑制、ひいては摩擦係数の上昇による異常効きや鳴き現象の発生を効果的に抑制することができない。特に、昨今の銅フリー化の動きの中では、銅による面粗し効果を期待することができず、高湿環境下における初期ブレーキ操作時の、効きの異常上昇に伴って、ブレーキフィーリングの悪化を招くと共に、鳴き現象が発生していた。 (Action effect)
According to the manufacturing method of the friction material and the friction material according to the present embodiment, the generation of the squeal phenomenon is suppressed in the high humidity environment by suppressing the increase of the real contact area of the friction material with the mating material at the time of initial braking operation. It can be reduced. In the conventional friction material containing copper, due to the ductility of copper, the wear powder is taken in because it spreads and spreads within the friction surface between the friction material and the rotor which is the opposite material while taking in some wear powder. It is repeated that copper is discharged from within the friction surface while appropriately roughening the mating material. As a result, without increasing the true contact area between the friction material and the mating material, the occurrence of abnormal effect and noise due to the increase of the friction coefficient is suppressed. However, when left in a high-humidity environment, wear powder absorbs moisture and condenses, so the surface roughening action with copper alone suppresses the true contact area, which results in abnormal effect and noise due to an increase in the coefficient of friction. Can not be effectively suppressed. In particular, in the recent movement toward copper-free, it is not possible to expect surface roughening effects due to copper, and due to the abnormal rise in effectiveness at the time of initial brake operation in a high humidity environment, Along with the deterioration, there was a screeching phenomenon.
　本実施形態に摩擦材の製造方法及び摩擦材によれば、粉体状の吸水性ポリマーの存在により、摩擦材と相手材との摩擦面における水分を効率よく除去されて摩耗粉同士の凝集が抑制され、摩擦材と相手材との真実接触面積の増大を抑制することができる。これにより、高湿環境下における初期ブレーキ操作時の鳴き現象の発生を効果的に低減できる。 According to the manufacturing method of the friction material and the friction material in the present embodiment, the presence of the powdery water absorbing polymer efficiently removes the water on the friction surface between the friction material and the mating material, and the aggregation of the wear powder is caused. Thus, the increase in the true contact area between the friction material and the mating material can be suppressed. As a result, the occurrence of the noise phenomenon at the time of the initial brake operation in a high humidity environment can be effectively reduced.
　特に、本実施形態に係る摩擦材の製造方法及び摩擦材によれば、粉体状の吸水性ポリマーを摩擦材原料として混合することで、粉体状の吸水性ポリマーはその吸水性能を良好に保持した状態で摩擦材中に存在することとなる。一方、水溶液状やエマルジョン状で摩擦材原料と混合された場合には、カルボキシ基をはじめとする吸水性ポリマーの親水基は、摩擦材原料に含まれるｐＨ調整材の水酸化カルシウム等に由来する二価金属イオン等と不可逆的なイオン架橋を形成することから吸水性能が低下する。本実施形態に係る摩擦材の製造方法及び摩擦材によれば、粉体状の吸水性ポリマーはその親水基が不可逆的なイオン架橋を形成せずに残存しやくすなるため、摩擦面内の水分を効果的に吸収することができる。 In particular, according to the method for producing a friction material and the friction material according to the present embodiment, the powdery water-absorbing polymer has good water absorption performance by mixing the powdery water-absorbing polymer as a friction material raw material It will exist in a friction material in the state hold | maintained. On the other hand, when an aqueous solution or emulsion is mixed with the friction material raw material, the hydrophilic groups of the water absorbing polymer including the carboxy group are derived from calcium hydroxide or the like of the pH adjusting material contained in the friction material raw material The formation of irreversible ionic crosslinks with divalent metal ions etc. reduces the water absorption performance. According to the method for producing the friction material and the friction material according to the present embodiment, since the water-absorbing polymer in powder form is easily left without forming the ionic crosslinks irreversibly, Water can be absorbed effectively.
　更に、本実施形態に係る摩擦材の製造方法及び摩擦材によれば、好ましくはモース硬度６．５以上で平均粒子径が１０～２００μｍである無機充填材を摩擦材原料に対して０．１～１．０重量％含有することにより、相手材に対する適度な面粗し効果を得ることができる。この面粗し効果により摩耗粉の排出が繰り返され、摩擦材の相手材との真実接触面積の増大が抑制される。かかる効果も相まって、本実施形態の摩擦材の製造方法及び摩擦材は、高湿環境下での放置後に初期ブレーキ制動時の鳴き現象の発生を確実に低減できる。 Furthermore, according to the method for producing a friction material and the friction material according to the present embodiment, an inorganic filler having a Mohs hardness of 6.5 or more and an average particle diameter of 10 to 200 μm is preferably added to the friction material as 0.1. By containing up to 1.0% by weight, it is possible to obtain an appropriate surface roughening effect on the counterpart material. By the surface roughening effect, the discharge of the wear powder is repeated, and the increase in the real contact area of the friction material with the mating material is suppressed. Combined with such effects, the method of manufacturing the friction material and the friction material of the present embodiment can reliably reduce the occurrence of the squeal phenomenon at the time of initial brake braking after leaving in a high humidity environment.
　以下に、本実施形態に係る摩擦材の実施例について説明するが、本発明はこれらの実施例に限定するものではない。 Examples of the friction material according to the present embodiment will be described below, but the present invention is not limited to these examples.
　実施例１～３１及び比較例１～３として、図１～２に示す配合量に従って摩擦材原料を配合し作製した摩擦材をブレーキパッドに用い、一般効力、耐摩耗性、振動、ブレーキ鳴きについて評価を行った。なお、図中の各摩擦材原料の配合量の単位は、摩擦材原料全体に対する重量％である。 In Examples 1 to 31 and Comparative Examples 1 to 3, the friction material prepared by blending the friction material raw material according to the compounding amount shown in FIGS. 1 and 2 is used as a brake pad, and general efficacy, wear resistance, vibration and brake noise I made an evaluation. In addition, the unit of the compounding quantity of each friction material raw material in a figure is weight% with respect to the whole friction material raw material.
（一般効力）
　ＪＡＳＯ　Ｃ４０６に準じて、第２効力試験の初速５０ｋｍ／ｈと１００ｋｍ／ｈ時の平均摩擦数（μ）、及び、フェード摩擦係数（μ）を測定した。 (General efficacy)
The average friction number (μ) and the fade friction coefficient (μ) at an initial velocity of 50 km / h and 100 km / h in the second efficacy test were measured according to JASO C406.
　ここでは、第２効力試験の初速５０ｋｍ／ｈと１００ｋｍ／ｈ時の平均摩擦数を、下記の基準にて３段階で評価した。
　〇：平均摩擦係数０．３７以上０．４３以下
　△：平均摩擦係数０．３４以上０．３７未満、又は、０．４３超え０．４６未満
　×：平均摩擦係数０．３４未満、又は、０．４６超える Here, the average friction number at an initial speed of 50 km / h and 100 km / h of the second efficacy test was evaluated in three stages based on the following criteria.
:: Average friction coefficient 0.37 or more and 0.43 or less Δ: Average friction coefficient 0.34 or more and less than 0.37, or more than 0.43 and less than 0.46 ×: Average friction coefficient less than 0.34 or 0 More than .46
　フェード摩擦係数は、下記の基準にて３段階で評価した。
　〇：フェード摩擦係数０．３以上
　△：フェード摩擦係数０．２以上０．３未満
　×：フェード摩擦係数０．２未満 The fade coefficient of friction was evaluated in three stages according to the following criteria.
○: fade coefficient of friction 0.3 or more Δ: fade coefficient of friction 0.2 or more and less than 0.3 ×: fade coefficient of friction less than 0.2
（耐摩耗性）
　ＪＡＳＯ　Ｃ４２７に準じて、１００℃、２００℃、４００℃の各温度における摩耗試験を行い、摩耗材の厚み（ｍｍ）を測定し、摩耗量を算出した。制動回数１０００回当たりの摩耗量に換算し、下記の基準にて４段階で評価した。
　◎：０．２０ｍｍ未満
　〇：０．２０ｍｍ以上０．２５ｍｍ未満
　△：０．２５ｍｍ以上０．３０ｍｍ未満
　×：０．３０ｍｍ以上 (Abrasion resistance)
According to JASO C 427, the abrasion test was performed at each temperature of 100 ° C., 200 ° C. and 400 ° C., the thickness (mm) of the abrasion material was measured, and the amount of abrasion was calculated. It was converted to the amount of wear per 1000 times of braking times, and was evaluated in four stages according to the following criteria.
:: less than 0.20 mm :: 0.20 mm or more and less than 0.25 mm 0.25: 0.25 mm or more and less than 0.30 mm ×: 0.30 mm or more
（振動）
　ブレーキ振動に影響するロータ摩耗量を評価した。サンプルとして、摩擦材２５ｍｍ×２５ｍｍのテストピースを使用し、当該テストピースをロータに面圧０．０５ＭＰａで押し付けた状態で、速度１００ｋｍ／ｈで２４時間空転した際のロータ摩耗量を計測した（低面圧攻撃性）。ここでは、下記の基準にて３段階で評価した。
　〇：ロータ摩耗量１０μｍ未満
　△：ロータ摩耗量１０μｍ以上２０μｍ未満
　×：ロータ摩耗量２０μｍ以上 (vibration)
The amount of rotor wear affecting brake vibration was evaluated. As a sample, a test piece of friction material 25 mm × 25 mm was used, and the rotor wear amount was measured when the test piece was idled at a speed of 100 km / h for 24 hours while being pressed against the rotor at a surface pressure of 0.05 MPa Low pressure attack). Here, it evaluated in three steps by the following standard.
:: Rotor wear amount less than 10 μm :: Rotor wear amount 10 μm or more and less than 20 μm ×: Rotor wear amount 20 μm or more
（鳴き）
　実車を使用しＪＡＳＯ　Ｃ４０６相当の擦り合わせを実施後、一晩屋外で放置した。この実車を使用し、翌朝、初速５ｋｍ／ｈ、減速度０．１Ｇにて前後各１０回制動し、発生したブレーキ鳴きの車内異音を評価した。ここでは、下記の基準にて２段階で評価した。
　〇：異音発生なし、又は、わずかに聞き取れるが、一般ドライバーが不快に感じない許容レベルでの異音の発生
　×：周囲の音に関わらずはっきりと聞こえ、一般ドライバーが不快に感じるレベルの異音の発生 (Screaming)
After using an actual vehicle and performing JASO C406 equivalent rubbing, it was left outdoors overnight. Using this vehicle, the vehicle was braked ten times each before and after at an initial speed of 5 km / h and deceleration of 0.1 G in the next morning, and the generated noise in the vehicle was evaluated. Here, evaluation was made in two stages according to the following criteria.
A: Generation of abnormal noise at an acceptable level at which noise does not occur or is slightly audible but the general driver does not feel uncomfortable ×: Difference in level at which the general driver feels unpleasant regardless of surrounding sounds Sound generation
　結果を図１～２に示す。実施例１～３１では、一般効力、耐摩耗性、振動、及び鳴き現象について、良好な結果が得られた。これにより、本実施例の摩擦材は、特に、吸水性ポリマーを０．１～３．０重量％含有し、モース硬度６．５以上で平均粒子径１０～２００ｎｍの無機充填材を０．１～１．０重量％含有した場合（実施例７～１７、１９～２１）、一般効力、耐摩耗性、振動、及び鳴き現象について、より良好な結果となった。一方、粉体状のポリアクリル酸ナトリウムを含有しない比較例１～３では、鳴きの発生が確認されたことから、本実施例で確認された鳴き現象発生の低減効果は粉体状の吸水性ポリマーによるものであることは明確である。また、粉体状の吸水性ポリマーは、架橋及び非架橋タイプを問わず、その効果を発揮し得ることも確認できた。 The results are shown in FIGS. In Examples 1 to 31, good results were obtained for the general efficacy, the wear resistance, the vibration and the squeal phenomenon. Thus, the friction material of this example contains, in particular, 0.1 to 3.0% by weight of a water absorbing polymer, and an inorganic filler having an average particle diameter of 10 to 200 nm and a Mohs hardness of 6.5 or more and 0.1. In the case of containing ̃1.0% by weight (Examples 7 to 17 and 19 to 21), better results were obtained for the general efficacy, the abrasion resistance, the vibration and the squeal phenomenon. On the other hand, in Comparative Examples 1 to 3 which do not contain powdery sodium polyacrylate, the occurrence of the squeal was confirmed, and therefore the reduction effect of the squeal phenomenon occurrence confirmed in the present example is the powdery water absorption. It is clear that it is due to the polymer. Further, it was also confirmed that the powdery water-absorbing polymer can exert its effect regardless of the crosslinked and non-crosslinked types.

Claims (6)

  1. 　元素として銅の含有量が摩擦材全体に対して０．５重量％以下である摩擦材の製造方法であって、
    　繊維基材、結合材、粉体状の吸水性ポリマーを含有する有機充填材、及び、水酸化カルシウムを含有する無機充填材を含む摩擦材原料を混合して摩擦材原料混合物を得る混合工程と、
    　前記混合工程で得られた前記摩擦材原料混合物を所定の形状に成形する成形工程と、を含む摩擦材の製造方法。     A method of producing a friction material, wherein the content of copper as an element is 0.5% by weight or less based on the entire friction material,
    A mixing step of mixing a friction material material containing a fibrous base material, a binder, an organic filler containing a powdery water-absorbing polymer, and an inorganic filler containing calcium hydroxide to obtain a friction material mixture ,
    Forming the friction material raw material mixture obtained in the mixing step into a predetermined shape.
  2. 　前記混合工程において、前記摩擦材原料全体に対して水分含有量が１．０重量％以下である請求項１に記載の摩擦材の製造方法。 The method for producing a friction material according to claim 1, wherein the water content in the mixing step is 1.0% by weight or less with respect to the entire friction material raw material.
  3. 　前記混合工程において、前記摩擦材原料全体に対して前記吸水性ポリマーを０．１～３．０重量％混合する請求項１又は２に記載の摩擦材の製造方法。 3. The method for producing a friction material according to claim 1, wherein the water absorbing polymer is mixed in an amount of 0.1 to 3.0% by weight based on the entire friction material raw material in the mixing step.
  4. 　前記吸水性ポリマーが、ポリアクリル酸ナトリウムである請求項１～３の何れか一項に記載の摩擦材の製造方法。 The method for producing a friction material according to any one of claims 1 to 3, wherein the water absorbing polymer is sodium polyacrylate.
  5. 　前記混合工程において、前記摩擦材原料がモース硬度６．５以上で、平均粒子径１０～２００ｎｍの前記無機充填材を前記摩擦材原料全体に対して０．１～１．０重量％含有する請求項１～４の何れか一項に記載の摩擦材の製造方法。 In the mixing step, the friction material material contains 0.1 to 1.0% by weight of the inorganic filler having a Mohs hardness of 6.5 or more and an average particle diameter of 10 to 200 nm with respect to the whole friction material material. A method of producing a friction material according to any one of Items 1 to 4.
  6. 　繊維基材、結合材、有機充填材、及び、無機充填材を含有し、
    　元素として銅の含有量が摩擦材全体に対して０．５重量％以下であり、前記有機充填材として粉体状の吸水性ポリマーを含有し、前記無機充填材として水酸化カルシウムを含有する摩擦材。     Contains a fiber base, a binder, an organic filler, and an inorganic filler,
    The friction is such that the content of copper as an element is 0.5% by weight or less with respect to the entire friction material, contains a powdery water-absorbing polymer as the organic filler, and contains calcium hydroxide as the inorganic filler. Material.
PCT/JP2018/010113 2017-03-15 2018-03-15 Method for producing friction material, and friction material WO2018168980A1 (en)

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Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN113774664A (en) * 2021-09-18 2021-12-10 岳阳澳源通信材料有限公司 Water-blocking yarn, preparation method thereof and application thereof in optical cable and optical fiber sleeve

Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
RU2265630C1 (en) * 2004-06-22 2005-12-10 Алтайский государственный университет Friction material
JP2008024891A (en) * 2006-07-25 2008-02-07 Advics:Kk Friction material
WO2016047723A1 (en) * 2014-09-25 2016-03-31 株式会社アドヴィックス Friction material and method for producing friction material
JP2017025286A (en) * 2015-07-22 2017-02-02 日清紡ブレーキ株式会社 Friction material

Patent Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
RU2265630C1 (en) * 2004-06-22 2005-12-10 Алтайский государственный университет Friction material
JP2008024891A (en) * 2006-07-25 2008-02-07 Advics:Kk Friction material
WO2016047723A1 (en) * 2014-09-25 2016-03-31 株式会社アドヴィックス Friction material and method for producing friction material
JP2017025286A (en) * 2015-07-22 2017-02-02 日清紡ブレーキ株式会社 Friction material

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN113774664A (en) * 2021-09-18 2021-12-10 岳阳澳源通信材料有限公司 Water-blocking yarn, preparation method thereof and application thereof in optical cable and optical fiber sleeve
CN113774664B (en) * 2021-09-18 2022-07-29 岳阳澳源通信材料有限公司 Water-blocking yarn, preparation method thereof and application thereof in optical cable and optical fiber sleeve

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