WO2024019126A1 - Friction material composition and friction material - Google Patents
Friction material composition and friction material Download PDFInfo
- Publication number
- WO2024019126A1 WO2024019126A1 PCT/JP2023/026669 JP2023026669W WO2024019126A1 WO 2024019126 A1 WO2024019126 A1 WO 2024019126A1 JP 2023026669 W JP2023026669 W JP 2023026669W WO 2024019126 A1 WO2024019126 A1 WO 2024019126A1
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- WIPO (PCT)
- Prior art keywords
- friction material
- material composition
- friction
- zirconium oxide
- mass
- Prior art date
Links
- 239000002783 friction material Substances 0.000 title claims abstract description 193
- 239000002131 composite material Substances 0.000 title description 2
- 239000000203 mixture Substances 0.000 claims abstract description 114
- RVTZCBVAJQQJTK-UHFFFAOYSA-N oxygen(2-);zirconium(4+) Chemical compound [O-2].[O-2].[Zr+4] RVTZCBVAJQQJTK-UHFFFAOYSA-N 0.000 claims abstract description 79
- 229910001928 zirconium oxide Inorganic materials 0.000 claims abstract description 79
- VTHJTEIRLNZDEV-UHFFFAOYSA-L magnesium dihydroxide Chemical compound [OH-].[OH-].[Mg+2] VTHJTEIRLNZDEV-UHFFFAOYSA-L 0.000 claims abstract description 58
- 239000000347 magnesium hydroxide Substances 0.000 claims abstract description 58
- 229910001862 magnesium hydroxide Inorganic materials 0.000 claims abstract description 58
- RYGMFSIKBFXOCR-UHFFFAOYSA-N Copper Chemical compound [Cu] RYGMFSIKBFXOCR-UHFFFAOYSA-N 0.000 claims abstract description 31
- 229910052802 copper Inorganic materials 0.000 claims abstract description 31
- 239000010949 copper Substances 0.000 claims abstract description 31
- 239000011256 inorganic filler Substances 0.000 claims abstract description 26
- 229910003475 inorganic filler Inorganic materials 0.000 claims abstract description 26
- 229920001971 elastomer Polymers 0.000 claims description 35
- 239000000806 elastomer Substances 0.000 claims description 34
- 238000000465 moulding Methods 0.000 claims description 21
- 239000012766 organic filler Substances 0.000 claims description 16
- 230000000052 comparative effect Effects 0.000 description 45
- JEIPFZHSYJVQDO-UHFFFAOYSA-N iron(III) oxide Inorganic materials O=[Fe]O[Fe]=O JEIPFZHSYJVQDO-UHFFFAOYSA-N 0.000 description 34
- 238000012360 testing method Methods 0.000 description 34
- 230000000694 effects Effects 0.000 description 33
- 239000002245 particle Substances 0.000 description 28
- 239000000463 material Substances 0.000 description 24
- 239000002994 raw material Substances 0.000 description 20
- 238000000034 method Methods 0.000 description 19
- 238000002156 mixing Methods 0.000 description 18
- 230000002265 prevention Effects 0.000 description 18
- 239000000835 fiber Substances 0.000 description 16
- 230000006872 improvement Effects 0.000 description 13
- 230000006866 deterioration Effects 0.000 description 11
- 239000000395 magnesium oxide Substances 0.000 description 10
- CPLXHLVBOLITMK-UHFFFAOYSA-N magnesium oxide Inorganic materials [Mg]=O CPLXHLVBOLITMK-UHFFFAOYSA-N 0.000 description 10
- AXZKOIWUVFPNLO-UHFFFAOYSA-N magnesium;oxygen(2-) Chemical compound [O-2].[Mg+2] AXZKOIWUVFPNLO-UHFFFAOYSA-N 0.000 description 10
- 238000004519 manufacturing process Methods 0.000 description 10
- 238000004088 simulation Methods 0.000 description 9
- 239000000314 lubricant Substances 0.000 description 8
- 239000002585 base Substances 0.000 description 7
- 239000011248 coating agent Substances 0.000 description 7
- 238000000576 coating method Methods 0.000 description 7
- 239000011230 binding agent Substances 0.000 description 6
- 238000011156 evaluation Methods 0.000 description 6
- 229920005989 resin Polymers 0.000 description 6
- 239000011347 resin Substances 0.000 description 6
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 6
- OKTJSMMVPCPJKN-UHFFFAOYSA-N Carbon Chemical compound [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 description 5
- UQSXHKLRYXJYBZ-UHFFFAOYSA-N Iron oxide Chemical compound [Fe]=O UQSXHKLRYXJYBZ-UHFFFAOYSA-N 0.000 description 5
- 238000005299 abrasion Methods 0.000 description 5
- 230000018044 dehydration Effects 0.000 description 5
- 238000006297 dehydration reaction Methods 0.000 description 5
- 229910052751 metal Inorganic materials 0.000 description 5
- 239000002184 metal Substances 0.000 description 5
- MKYBYDHXWVHEJW-UHFFFAOYSA-N N-[1-oxo-1-(2,4,6,7-tetrahydrotriazolo[4,5-c]pyridin-5-yl)propan-2-yl]-2-[[3-(trifluoromethoxy)phenyl]methylamino]pyrimidine-5-carboxamide Chemical compound O=C(C(C)NC(=O)C=1C=NC(=NC=1)NCC1=CC(=CC=C1)OC(F)(F)F)N1CC2=C(CC1)NN=N2 MKYBYDHXWVHEJW-UHFFFAOYSA-N 0.000 description 4
- NIPNSKYNPDTRPC-UHFFFAOYSA-N N-[2-oxo-2-(2,4,6,7-tetrahydrotriazolo[4,5-c]pyridin-5-yl)ethyl]-2-[[3-(trifluoromethoxy)phenyl]methylamino]pyrimidine-5-carboxamide Chemical compound O=C(CNC(=O)C=1C=NC(=NC=1)NCC1=CC(=CC=C1)OC(F)(F)F)N1CC2=C(CC1)NN=N2 NIPNSKYNPDTRPC-UHFFFAOYSA-N 0.000 description 4
- AFCARXCZXQIEQB-UHFFFAOYSA-N N-[3-oxo-3-(2,4,6,7-tetrahydrotriazolo[4,5-c]pyridin-5-yl)propyl]-2-[[3-(trifluoromethoxy)phenyl]methylamino]pyrimidine-5-carboxamide Chemical compound O=C(CCNC(=O)C=1C=NC(=NC=1)NCC1=CC(=CC=C1)OC(F)(F)F)N1CC2=C(CC1)NN=N2 AFCARXCZXQIEQB-UHFFFAOYSA-N 0.000 description 4
- RTAQQCXQSZGOHL-UHFFFAOYSA-N Titanium Chemical compound [Ti] RTAQQCXQSZGOHL-UHFFFAOYSA-N 0.000 description 4
- 239000013078 crystal Substances 0.000 description 4
- 230000003247 decreasing effect Effects 0.000 description 4
- 238000010438 heat treatment Methods 0.000 description 4
- 238000003703 image analysis method Methods 0.000 description 4
- 238000000691 measurement method Methods 0.000 description 4
- 238000003921 particle size analysis Methods 0.000 description 4
- FYYHWMGAXLPEAU-UHFFFAOYSA-N Magnesium Chemical compound [Mg] FYYHWMGAXLPEAU-UHFFFAOYSA-N 0.000 description 3
- 241000156302 Porcine hemagglutinating encephalomyelitis virus Species 0.000 description 3
- 229910052799 carbon Inorganic materials 0.000 description 3
- 239000000428 dust Substances 0.000 description 3
- XLYOFNOQVPJJNP-UHFFFAOYSA-M hydroxide Chemical compound [OH-] XLYOFNOQVPJJNP-UHFFFAOYSA-M 0.000 description 3
- 230000001771 impaired effect Effects 0.000 description 3
- 229910052749 magnesium Inorganic materials 0.000 description 3
- 239000011777 magnesium Substances 0.000 description 3
- 238000005259 measurement Methods 0.000 description 3
- 229910052976 metal sulfide Inorganic materials 0.000 description 3
- 239000000843 powder Substances 0.000 description 3
- 230000007704 transition Effects 0.000 description 3
- 239000004636 vulcanized rubber Substances 0.000 description 3
- 229920000181 Ethylene propylene rubber Polymers 0.000 description 2
- 244000043261 Hevea brasiliensis Species 0.000 description 2
- 229920000459 Nitrile rubber Polymers 0.000 description 2
- NBIIXXVUZAFLBC-UHFFFAOYSA-N Phosphoric acid Chemical compound OP(O)(O)=O NBIIXXVUZAFLBC-UHFFFAOYSA-N 0.000 description 2
- 239000005062 Polybutadiene Substances 0.000 description 2
- 229920000800 acrylic rubber Polymers 0.000 description 2
- 229910052783 alkali metal Inorganic materials 0.000 description 2
- 238000004458 analytical method Methods 0.000 description 2
- 239000004760 aramid Substances 0.000 description 2
- TZCXTZWJZNENPQ-UHFFFAOYSA-L barium sulfate Chemical compound [Ba+2].[O-]S([O-])(=O)=O TZCXTZWJZNENPQ-UHFFFAOYSA-L 0.000 description 2
- 230000015572 biosynthetic process Effects 0.000 description 2
- 229920005549 butyl rubber Polymers 0.000 description 2
- 239000011329 calcined coke Substances 0.000 description 2
- 230000008859 change Effects 0.000 description 2
- 238000000354 decomposition reaction Methods 0.000 description 2
- 229920003244 diene elastomer Polymers 0.000 description 2
- 238000009826 distribution Methods 0.000 description 2
- 230000007613 environmental effect Effects 0.000 description 2
- 239000010439 graphite Substances 0.000 description 2
- 229910002804 graphite Inorganic materials 0.000 description 2
- 239000012784 inorganic fiber Substances 0.000 description 2
- 229920003049 isoprene rubber Polymers 0.000 description 2
- 150000002739 metals Chemical class 0.000 description 2
- 238000001000 micrograph Methods 0.000 description 2
- 239000003607 modifier Substances 0.000 description 2
- 229920003052 natural elastomer Polymers 0.000 description 2
- 229920001194 natural rubber Polymers 0.000 description 2
- 238000005498 polishing Methods 0.000 description 2
- 229920001084 poly(chloroprene) Polymers 0.000 description 2
- 229920000058 polyacrylate Polymers 0.000 description 2
- 229920002857 polybutadiene Polymers 0.000 description 2
- 238000000790 scattering method Methods 0.000 description 2
- 229920002379 silicone rubber Polymers 0.000 description 2
- 239000004945 silicone rubber Substances 0.000 description 2
- 230000003068 static effect Effects 0.000 description 2
- 229920003048 styrene butadiene rubber Polymers 0.000 description 2
- 229920001187 thermosetting polymer Polymers 0.000 description 2
- -1 titanates Chemical compound 0.000 description 2
- 229920002972 Acrylic fiber Polymers 0.000 description 1
- 244000226021 Anacardium occidentale Species 0.000 description 1
- 229920000049 Carbon (fiber) Polymers 0.000 description 1
- 235000019492 Cashew oil Nutrition 0.000 description 1
- 229920003043 Cellulose fiber Polymers 0.000 description 1
- 239000004709 Chlorinated polyethylene Substances 0.000 description 1
- 229910000881 Cu alloy Inorganic materials 0.000 description 1
- 229920000089 Cyclic olefin copolymer Polymers 0.000 description 1
- MBMLMWLHJBBADN-UHFFFAOYSA-N Ferrous sulfide Chemical compound [Fe]=S MBMLMWLHJBBADN-UHFFFAOYSA-N 0.000 description 1
- WHXSMMKQMYFTQS-UHFFFAOYSA-N Lithium Chemical compound [Li] WHXSMMKQMYFTQS-UHFFFAOYSA-N 0.000 description 1
- 229920000877 Melamine resin Polymers 0.000 description 1
- 239000004640 Melamine resin Substances 0.000 description 1
- 229910000831 Steel Inorganic materials 0.000 description 1
- 239000002174 Styrene-butadiene Substances 0.000 description 1
- ATJFFYVFTNAWJD-UHFFFAOYSA-N Tin Chemical compound [Sn] ATJFFYVFTNAWJD-UHFFFAOYSA-N 0.000 description 1
- 229920006311 Urethane elastomer Polymers 0.000 description 1
- HCHKCACWOHOZIP-UHFFFAOYSA-N Zinc Chemical compound [Zn] HCHKCACWOHOZIP-UHFFFAOYSA-N 0.000 description 1
- 239000005083 Zinc sulfide Substances 0.000 description 1
- 230000002159 abnormal effect Effects 0.000 description 1
- 239000003513 alkali Substances 0.000 description 1
- 150000001340 alkali metals Chemical class 0.000 description 1
- 229910002065 alloy metal Inorganic materials 0.000 description 1
- 229910052782 aluminium Inorganic materials 0.000 description 1
- XAGFODPZIPBFFR-UHFFFAOYSA-N aluminium Chemical compound [Al] XAGFODPZIPBFFR-UHFFFAOYSA-N 0.000 description 1
- 229910000147 aluminium phosphate Inorganic materials 0.000 description 1
- 229940007424 antimony trisulfide Drugs 0.000 description 1
- NVWBARWTDVQPJD-UHFFFAOYSA-N antimony(3+);trisulfide Chemical compound [S-2].[S-2].[S-2].[Sb+3].[Sb+3] NVWBARWTDVQPJD-UHFFFAOYSA-N 0.000 description 1
- 229920006231 aramid fiber Polymers 0.000 description 1
- 229920003235 aromatic polyamide Polymers 0.000 description 1
- AXCZMVOFGPJBDE-UHFFFAOYSA-L calcium dihydroxide Chemical compound [OH-].[OH-].[Ca+2] AXCZMVOFGPJBDE-UHFFFAOYSA-L 0.000 description 1
- 239000000920 calcium hydroxide Substances 0.000 description 1
- 229910001861 calcium hydroxide Inorganic materials 0.000 description 1
- NNLOHLDVJGPUFR-UHFFFAOYSA-L calcium;3,4,5,6-tetrahydroxy-2-oxohexanoate Chemical compound [Ca+2].OCC(O)C(O)C(O)C(=O)C([O-])=O.OCC(O)C(O)C(O)C(=O)C([O-])=O NNLOHLDVJGPUFR-UHFFFAOYSA-L 0.000 description 1
- 238000004364 calculation method Methods 0.000 description 1
- 239000006229 carbon black Substances 0.000 description 1
- 239000004917 carbon fiber Substances 0.000 description 1
- 235000020226 cashew nut Nutrition 0.000 description 1
- 239000010467 cashew oil Substances 0.000 description 1
- 229940059459 cashew oil Drugs 0.000 description 1
- 239000003638 chemical reducing agent Substances 0.000 description 1
- 239000000571 coke Substances 0.000 description 1
- 238000001816 cooling Methods 0.000 description 1
- 229920001577 copolymer Polymers 0.000 description 1
- RKTYLMNFRDHKIL-UHFFFAOYSA-N copper;5,10,15,20-tetraphenylporphyrin-22,24-diide Chemical compound [Cu+2].C1=CC(C(=C2C=CC([N-]2)=C(C=2C=CC=CC=2)C=2C=CC(N=2)=C(C=2C=CC=CC=2)C2=CC=C3[N-]2)C=2C=CC=CC=2)=NC1=C3C1=CC=CC=C1 RKTYLMNFRDHKIL-UHFFFAOYSA-N 0.000 description 1
- 238000005260 corrosion Methods 0.000 description 1
- NJLLQSBAHIKGKF-UHFFFAOYSA-N dipotassium dioxido(oxo)titanium Chemical compound [K+].[K+].[O-][Ti]([O-])=O NJLLQSBAHIKGKF-UHFFFAOYSA-N 0.000 description 1
- 229920005558 epichlorohydrin rubber Polymers 0.000 description 1
- 239000003822 epoxy resin Substances 0.000 description 1
- 229920001973 fluoroelastomer Polymers 0.000 description 1
- 239000003365 glass fiber Substances 0.000 description 1
- 229920002681 hypalon Polymers 0.000 description 1
- 150000003949 imides Chemical class 0.000 description 1
- 238000007654 immersion Methods 0.000 description 1
- 239000004615 ingredient Substances 0.000 description 1
- 229910052744 lithium Inorganic materials 0.000 description 1
- OBTSLRFPKIKXSZ-UHFFFAOYSA-N lithium potassium Chemical compound [Li].[K] OBTSLRFPKIKXSZ-UHFFFAOYSA-N 0.000 description 1
- SWHAQEYMVUEVNF-UHFFFAOYSA-N magnesium potassium Chemical compound [Mg].[K] SWHAQEYMVUEVNF-UHFFFAOYSA-N 0.000 description 1
- ZQKXQUJXLSSJCH-UHFFFAOYSA-N melamine cyanurate Chemical compound NC1=NC(N)=NC(N)=N1.O=C1NC(=O)NC(=O)N1 ZQKXQUJXLSSJCH-UHFFFAOYSA-N 0.000 description 1
- 239000010445 mica Substances 0.000 description 1
- 229910052618 mica group Inorganic materials 0.000 description 1
- 239000011490 mineral wool Substances 0.000 description 1
- 230000004048 modification Effects 0.000 description 1
- 238000012986 modification Methods 0.000 description 1
- CWQXQMHSOZUFJS-UHFFFAOYSA-N molybdenum disulfide Chemical compound S=[Mo]=S CWQXQMHSOZUFJS-UHFFFAOYSA-N 0.000 description 1
- 229910052982 molybdenum disulfide Inorganic materials 0.000 description 1
- CLNYHERYALISIR-UHFFFAOYSA-N nona-1,3-diene Chemical compound CCCCCC=CC=C CLNYHERYALISIR-UHFFFAOYSA-N 0.000 description 1
- NDLPOXTZKUMGOV-UHFFFAOYSA-N oxo(oxoferriooxy)iron hydrate Chemical compound O.O=[Fe]O[Fe]=O NDLPOXTZKUMGOV-UHFFFAOYSA-N 0.000 description 1
- 239000005011 phenolic resin Substances 0.000 description 1
- 229920002589 poly(vinylethylene) polymer Polymers 0.000 description 1
- 229920000647 polyepoxide Polymers 0.000 description 1
- 229920013716 polyethylene resin Polymers 0.000 description 1
- 238000002360 preparation method Methods 0.000 description 1
- 230000008569 process Effects 0.000 description 1
- 230000001172 regenerating effect Effects 0.000 description 1
- 230000000717 retained effect Effects 0.000 description 1
- 239000005060 rubber Substances 0.000 description 1
- 150000003839 salts Chemical class 0.000 description 1
- GROMGGTZECPEKN-UHFFFAOYSA-N sodium metatitanate Chemical compound [Na+].[Na+].[O-][Ti](=O)O[Ti](=O)O[Ti]([O-])=O GROMGGTZECPEKN-UHFFFAOYSA-N 0.000 description 1
- 239000010935 stainless steel Substances 0.000 description 1
- 229910001220 stainless steel Inorganic materials 0.000 description 1
- 239000010959 steel Substances 0.000 description 1
- 239000000126 substance Substances 0.000 description 1
- 238000004381 surface treatment Methods 0.000 description 1
- 239000012209 synthetic fiber Substances 0.000 description 1
- 229920002994 synthetic fiber Polymers 0.000 description 1
- 238000010998 test method Methods 0.000 description 1
- 229920002725 thermoplastic elastomer Polymers 0.000 description 1
- 229910052718 tin Inorganic materials 0.000 description 1
- AFNRRBXCCXDRPS-UHFFFAOYSA-N tin(ii) sulfide Chemical compound [Sn]=S AFNRRBXCCXDRPS-UHFFFAOYSA-N 0.000 description 1
- ITRNXVSDJBHYNJ-UHFFFAOYSA-N tungsten disulfide Chemical compound S=[W]=S ITRNXVSDJBHYNJ-UHFFFAOYSA-N 0.000 description 1
- 238000009736 wetting Methods 0.000 description 1
- 239000002023 wood Substances 0.000 description 1
- 229910052725 zinc Inorganic materials 0.000 description 1
- 239000011701 zinc Substances 0.000 description 1
- 229910052984 zinc sulfide Inorganic materials 0.000 description 1
- DRDVZXDWVBGGMH-UHFFFAOYSA-N zinc;sulfide Chemical compound [S-2].[Zn+2] DRDVZXDWVBGGMH-UHFFFAOYSA-N 0.000 description 1
- 239000004711 α-olefin Substances 0.000 description 1
Classifications
-
- 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—Composition of linings ; Methods of manufacturing
Definitions
- the present invention relates to a friction material composition and a friction material.
- Friction materials are used in disc brake pads and brake shoes of braking devices such as disc brakes and drum brakes.
- Patent Document 1 discloses that a friction material composition that does not contain copper as an element or has a copper content of 0.5% by mass or less as an elemental copper contains a metal sulfide as an inorganic filler. Additionally, a friction material composition containing a reducing agent as an inorganic filler is described.
- Patent Document 2 describes a friction material made of a thermosetting resin containing 5 to 75% by volume of non-fibrous magnesium hydroxide powder that has been subjected to a surface treatment to increase its affinity with the thermosetting resin.
- Patent Document 3 discloses that a friction material composition of NAO material that does not contain a copper component contains monoclinic zirconium oxide with an average particle size of 1 to 8 ⁇ m as an inorganic friction modifier in an amount of 10 to 40% based on the total amount of the friction material composition. 1.5% by weight or more of elastic graphitized carbon as a carbonaceous lubricant based on the total amount of the friction material composition, and 2% or more of calcined coke with the elastic graphitized carbon based on the total amount of the friction material composition. It is described that the elastic graphitized carbon and the calcined coke are contained at a weight ratio of 4:6 to 8:2.
- the friction materials of the prior art as described above do not have sufficient effectiveness and wear resistance during high-speed braking in a high temperature range. Moreover, the rust prevention property on the contact surface with friction facing materials such as disc rotors and brake drums is also low. As described above, there is room for improvement in the conventional friction materials.
- One embodiment of the present invention has excellent effectiveness and wear resistance during high-speed braking in a high temperature range, has sufficient wear resistance even in a normal temperature range, and has sufficient wear resistance on the contact surface with the friction facing material.
- the purpose of the present invention is to provide a friction material having rust prevention properties.
- Friction materials containing specific amounts of magnesium and monoclinic zirconium oxide have excellent wear resistance and effectiveness during high-speed braking in high-temperature ranges, and have sufficient wear resistance even in normal temperature ranges such as when driving around town. It was discovered for the first time that the contact surface with the friction facing material has sufficient rust prevention properties, and this led to the completion of the present invention.
- the friction material composition according to one embodiment of the present invention is a friction material composition in which the content of copper in the friction material composition is less than 0.5% by mass as a copper element, and the friction material composition contains water as an inorganic filler.
- the friction material composition contains magnesium oxide and monoclinic zirconium oxide, and the content of the magnesium hydroxide in the friction material composition is 0.5% by mass or more and 10% by mass or less, and The content of monoclinic zirconium oxide is 5% by mass or more and 35% by mass or less.
- the content of copper which has a high environmental impact, is less than 0.5% by mass as a copper element, yet it has excellent effectiveness during high-speed braking in a high temperature range and wear resistance, and is suitable for regular use. It is possible to provide a friction material that has sufficient wear resistance even in a temperature range and also has sufficient rust prevention on the contact surface with the friction facing material.
- a friction material composition according to one aspect of the present invention is a friction material composition in which the content of copper in the friction material composition is less than 0.5% by mass as a copper element, and magnesium hydroxide is used as an inorganic filler. and monoclinic zirconium oxide, the content of the magnesium hydroxide in the friction material composition is 0.5% by mass or more and 10% by mass or less, and the monoclinic zirconium oxide in the friction material composition is The content of crystalline zirconium oxide is 5% by mass or more and 35% by mass or less.
- the friction material composition of this embodiment is intended to be a mixture of friction material raw materials containing the above-mentioned components.
- the friction material composition of this embodiment can be used to mold the friction material described below.
- the friction material composition of this embodiment is environmentally friendly because the content of copper in the friction material composition is less than 0.5% by mass as a copper element. Furthermore, because it contains specific amounts of magnesium hydroxide and monoclinic zirconium oxide as inorganic fillers, the copper content is less than 0.5% by mass as an elemental copper, but the effectiveness during high-speed braking at high temperatures is improved. It has the excellent effect of being able to provide a friction material that has excellent abrasion resistance, has sufficient abrasion resistance even in the normal temperature range, and has sufficient rust prevention properties on the contact surface with the friction face material. .
- the friction material using the friction material composition of this embodiment has improved wear resistance during high-speed braking in a high-temperature range (for example, 650°C or higher), thereby simultaneously achieving improved effectiveness during high-speed braking in a high-temperature range. can do. Furthermore, the improvement in wear resistance during high-speed braking in a high-temperature range can also be said to be an improvement in the strength of the friction material on the friction surface, which can also be expected to improve the heat resistance effect of the friction material.
- a friction material using the friction material composition of this embodiment has both wear resistance during high-speed braking in a high temperature range and wear resistance in a commonly used temperature range (for example, 100 to 200°C). Because of this, it has an excellent effect of having a longer life compared to conventional friction materials. Furthermore, the friction material using the friction material composition of this embodiment has excellent wear resistance, and thus releases less dust due to wear. As a result, excellent effects are achieved in that the wheels are less likely to be contaminated by dust and the amount of PM2.5 and PM10, which have a high environmental impact, is emitted in a small amount.
- the friction material using the friction material composition of this embodiment has sufficient rust prevention properties on the contact surface with the friction surface material, rust generated on the contact surface with the friction surface material causes the friction material to Hard to stick to wood. As a result, an excellent effect is achieved in that problems such as abnormal noise generation and surface peeling of the friction material are less likely to occur when the vehicle starts.
- the friction material composition of this embodiment having the above-mentioned characteristics can be used as a friction material used for the friction surface of disc brake pads and drum brake shoes for electric vehicles (EVs) and hybrid vehicles (HEVs). Therefore, it is particularly useful as a friction material composition. This is because EVs/HEVs are heavier than conventional gasoline vehicles due to their large batteries, and the contribution of regenerative braking during high-speed braking tends to be low. This is because the temperature of the brake pad or brake shoe tends to rise during high-speed braking, increasing the frequency at which the brake pad or brake shoe reaches high temperatures.
- EVs/HEVs are heavier than conventional gasoline vehicles due to their large batteries, and the contribution of regenerative braking during high-speed braking tends to be low. This is because the temperature of the brake pad or brake shoe tends to rise during high-speed braking, increasing the frequency at which the brake pad or brake shoe reaches high temperatures.
- the application of the friction material composition of this embodiment is not particularly limited to EV/HEV, but can be used for friction surfaces of disc brake pads, drum brake brake shoes, etc. employed in general vehicles including motorcycles. It can be suitably used as a friction material.
- the content of copper in the friction material composition is less than 0.5% by mass as a copper element.
- the friction material composition according to one embodiment of the present invention has a very low content of copper and copper alloy, which are highly harmful to the environment, and therefore has the effect of providing an environmentally friendly friction material. From the viewpoint of providing a friction material that is more environmentally friendly, the content of copper in the friction material composition is more preferably 0% by mass (copper-free). Copper contained in the friction material composition according to one embodiment of the present invention may be derived from copper fibers added as a fiber base material.
- the friction material composition according to one aspect of the present invention contains magnesium hydroxide in an amount of 0.5% by mass or more and 10% by mass or less based on 100% by mass of the friction material composition, as one type of inorganic filler. There is.
- magnesium hydroxide has low solubility in water, and alkali is less likely to disappear from the pad (friction surface, etc.) due to water wetting. For this reason, the rust prevention effect lasts longer than other alkaline materials. As a result, friction materials containing magnesium hydroxide maintain their anti-corrosion effect even when exposed to rain during the rainy season or when worn, such as with old pads.
- the pH of magnesium hydroxide is 10.5, which is not high enough to promote the decomposition of the resin contained as a binder in the friction material. For this reason, friction materials containing magnesium hydroxide are less likely to lose strength due to decomposition of the resin. As a result, the pad has good wear resistance.
- Magnesium hydroxide has a heat-resistant effect by absorbing heat from dehydration at 300 to 400°C. Magnesium hydroxide spread uniformly on the friction surface changes to magnesium oxide through dehydration. Magnesium oxide contributes to the formation of a stabilized zirconium oxide film by fusing with monoclinic zirconium oxide, which will be described later, due to the high heat generated by high-speed braking (high-load braking) in a high-temperature range. Stabilized zirconium oxide is easy to form a stable film and has excellent heat resistance. The stabilized zirconium oxide coating improves wear resistance by protecting the friction surfaces and thus improves the coefficient of friction ( ⁇ ).
- the content of magnesium hydroxide in the friction material composition of this embodiment is 0.5% by mass or more based on 100% by mass of the friction material composition, a sufficient amount of magnesium hydroxide spreads on the friction surface. , the effects of (i) and (ii) above are fully expressed. Further, if the content of magnesium hydroxide in the friction material composition of this embodiment is 10% by mass or less with respect to 100% by mass of the friction material composition, the effect of volume change due to dehydration of magnesium hydroxide is small, and friction The strength of the base material is less likely to decrease. As a result, the pad has good abrasion resistance in the commonly used temperature range, and a sufficient heat resistance effect can also be obtained.
- the content of magnesium hydroxide in the friction material composition is 0.8% by mass or more based on 100% by mass of the friction material composition. , preferably 5% by mass or less.
- the particle size of magnesium hydroxide is not particularly limited. Therefore, magnesium hydroxide having a particle size that is normally employed as an inorganic filler added to friction materials can be appropriately selected.
- the average particle size of magnesium hydroxide is preferably 2 ⁇ m or more, more preferably 4 ⁇ m or more.
- the average particle size of magnesium hydroxide is preferably 20 ⁇ m or less, more preferably 15 ⁇ m or less, because the effect of improving abrasion properties can be stably obtained at any location on the friction surface.
- the average particle size of magnesium hydroxide is the volume-based median diameter obtained by JIS Z 8825 "Particle size analysis - laser analysis/scattering method".
- JIS Z 8825 Particle size analysis - laser analysis/scattering method.
- JIS Z 8827-1 Particle size analysis - image analysis method.
- Static image analysis method to measure the volume-based particle size distribution and find the median diameter.
- the friction material composition according to one aspect of the present invention contains monoclinic zirconium oxide in an amount of 5% by mass or more and 35% by mass or less based on 100% by mass of the friction material composition, as one type of inorganic filler.
- monoclinic zirconium oxide refers to zirconium oxide whose crystal system is monoclinic. The crystal system of zirconium oxide undergoes a transition depending on the temperature. At room temperature (20°C), it is monoclinic, and as the temperature is raised, the crystal structure changes to tetragonal at 1170°C and cubic at 2370°C. Phase transitions are accompanied by volume changes.
- zirconium oxide is most stable in the monoclinic system at room temperature, but when fused with magnesium oxide, the cubic system becomes stable even at room temperature.
- Zirconium oxide stabilized in cubic form at room temperature is called "stabilized zirconium oxide.”
- Monoclinic zirconium oxide can be used for magnesium oxide (hydroxide in friction materials) due to the high heat generated by high-speed braking (high-load braking) in high-temperature ranges.
- magnesium oxide modified by dehydration
- it becomes stabilized zirconium oxide.
- the stabilized zirconium oxide coating formed on the friction surface protects the friction surface.
- no volume change occurs due to phase transition, so the strength of the friction material on the friction surface is less likely to decrease. As a result, the wear resistance of the pad is improved, and the coefficient of friction ( ⁇ ) is also improved.
- the thickness of the stabilized zirconium oxide coating formed on the friction surface changes depending on the content of monoclinic zirconium oxide in the friction material composition of this embodiment.
- the content of monoclinic zirconium oxide in the friction material composition of this embodiment is 5% by mass or more based on 100% by mass of the friction material composition, which is sufficient for the above effect (ii) to be expressed.
- a film of stabilized zirconium oxide with a certain thickness is formed. Further, if the content of monoclinic zirconium oxide in the friction material composition of this embodiment is 35% by mass or less based on 100% by mass of the friction material composition, the stabilized zirconium oxide film will not become too thick.
- the magnesium hydroxide is not buried in the stabilized zirconium oxide coating, so that the rust-resistant effect of the magnesium hydroxide is fully exhibited.
- the stabilized zirconium oxide coating is difficult to peel off from the friction surface, it is possible to prevent the friction area from becoming small due to variations in coating thickness and the effectiveness at high temperatures from decreasing. Therefore, the effect of (i) above is fully exhibited.
- the content of monoclinic zirconium oxide in the friction material composition is 20% by mass or more based on 100% by mass of the friction material composition. , preferably 30% by mass or less.
- the particle size of monoclinic zirconium oxide is not particularly limited. Therefore, monoclinic zirconium oxide having a particle size that is normally employed as an inorganic filler added to friction materials can be appropriately selected. From the viewpoint of handleability during production of the friction material composition, the average particle size of monoclinic zirconium oxide is preferably 1 ⁇ m or more, more preferably 3 ⁇ m or more, and even more preferably 5 ⁇ m or more. , more preferably 7 ⁇ m or more, and even more preferably 10 ⁇ m or more.
- the average particle size of the monoclinic zirconium oxide is 20 ⁇ m or less because it enables uniform mixing without bias during production of the friction material composition and has little effect on deterioration of wear resistance. It is preferably 18 ⁇ m or less, more preferably 16 ⁇ m or less.
- the average particle size of monoclinic zirconium oxide is the volume-based median diameter obtained by JIS Z 8825 "Particle size analysis - laser analysis/scattering method".
- JIS Z 8825 Particle size analysis - laser analysis/scattering method.
- the friction material composition according to one aspect of the present invention preferably contains a non-vulcanized elastomer as the organic filler.
- a non-vulcanized elastomer refers to an elastomer that has not been vulcanized.
- the non-vulcanized elastomer is preferably one that softens (has plasticity) in a common temperature range (for example, 100 to 200° C.) such as when driving around town.
- the type of non-vulcanized elastomer is not particularly limited, and any non-vulcanized elastomer can be preferably used.
- non-vulcanized elastomers include natural rubber (NR), isoprene rubber (IR), butadiene rubber (BR), styrene-butadiene rubber (SBR), chloroprene rubber (CR), and acrylonitrile-butadiene rubber (NBR).
- Sulfuric diene rubber Sulfuric diene rubber; butyl rubber (IIR), ethylene propylene rubber (EPM), urethane rubber (U), silicone rubber (Q), chlorosulfonated polyethylene (CSM), chlorinated polyethylene (CM), acrylic rubber (ACM) , non-vulcanized non-diene rubbers such as epichlorohydrin rubber (CO) and fluororubber (FKM); thermoplastic elastomers such as 1,2 polybutadiene, ethylene-octene copolymers, and ethylene- ⁇ -olefin copolymers; Can be done.
- the non-vulcanized elastomer can be used singly or in combination.
- the shape of the non-vulcanized elastomer is not particularly limited, and any shape can be used as appropriate. However, from the viewpoint of ease of mixing during production of the friction material composition, it is preferably granular.
- the content of the non-vulcanized elastomer in the friction material composition is not particularly limited, and can be determined as appropriate within a range in which the intended effect of containing the non-vulcanized elastomer is sufficiently exhibited. From the perspective of further improving the wear resistance and rust prevention properties of the friction material in the commonly used temperature range, the content of the non-vulcanized elastomer in the friction material composition is 0.0% based on 100% by mass of the friction material composition. It is preferably 5% by mass or more, more preferably 1% by mass or more.
- the content of non-vulcanized elastomer in the friction material composition is 10% by mass based on 100% by mass of the friction material composition. % or less, more preferably 3% by mass or less.
- the friction material composition of this embodiment includes a fiber base material, a binder, an organic filler different from the non-vulcanized elastomer, and an organic filler different from magnesium hydroxide and monoclinic zirconium oxide.
- the friction material may contain an inorganic filler as a raw material for the friction material.
- fiber base material examples include organic fibers, inorganic fibers, and metal fibers. These fibers may be natural fibers or artificially synthesized synthetic fibers. Examples of organic fibers include aromatic polyamide fibers (aramid fibers), acrylic fibers, cellulose fibers, and carbon fibers. Examples of the inorganic fiber include rock wool and glass fiber. Examples of metal fibers include fibers made of single metals such as steel, stainless steel, aluminum, zinc, and tin, as well as fibers made of alloy metals of the respective metals. The fiber base material can be used singly or in combination. The content of the fiber base material in the friction material composition is not particularly limited, and can be a content commonly employed in the technical field.
- the binding material has a function of binding friction material raw materials in the friction material composition.
- the binding material is not particularly limited as long as it can exhibit the above performance, and binding materials known in the technical field can be preferably used.
- Specific examples of the binder include resins such as phenol resin, epoxy resin, melamine resin, and imide resin.
- the binder can be used singly or in combination.
- the content of the binder in the friction material composition is not particularly limited, and can be a content commonly employed in the technical field. Further, the binder may contain modifying components such as silicone rubber, acrylic rubber, and cashew oil.
- the friction material composition of this embodiment may contain another organic filler different from the non-vulcanized elastomer to the extent that the effects of the present invention are not impaired.
- the organic filler has a function as a friction modifier to improve wear resistance and the like.
- the organic filler different from the non-vulcanized elastomer is not particularly limited as long as it can exhibit the above performance, and organic fillers known in the technical field can be preferably used. Specific examples of organic fillers different from non-vulcanized elastomers include rubber powder, tire powder, cashew dust, fluororesin, melamine cyanurate, polyethylene resin, and the like.
- One kind of organic filler can be used alone or a plurality of kinds can be used in combination. Further, the surface of the organic filler may be coated with phosphoric acid or fluororesin.
- the content of another organic filler different from the non-vulcanized elastomer is not particularly limited, and the total content of the organic filler including the non-vulcanized elastomer is the same as the content of organic fillers adopted in the technical field. It may be adjusted as appropriate so that it falls within the range.
- the friction material composition of this embodiment may contain a vulcanized elastomer (for example, vulcanized rubber) as long as the amount is small enough not to impair the effects of the non-vulcanized elastomer.
- the friction material composition of this embodiment may contain an inorganic filler different from monoclinic zirconium oxide and magnesium hydroxide as long as the effects of the present invention are not impaired.
- inorganics known in the art can preferably be used, such as barium sulfate, mica, iron oxide (ferrous oxide, (ferric oxide, etc.), titanates, calcium hydroxide, etc.
- titanates include alkali metal titanates, alkali metal titanate second group salts, and specific examples include potassium titanate, sodium titanate, lithium titanate, and lithium potassium titanate.
- the content of an inorganic filler different from monoclinic zirconium oxide and magnesium hydroxide in the friction material composition is not particularly limited, and the total content of inorganic fillers together with monoclinic zirconium oxide and magnesium hydroxide The amount may be adjusted as appropriate so that it falls within the range of inorganic filler content adopted in the technical field.
- the film formed on the friction surface during high-speed braking in the temperature range of 650°C or higher becomes stronger.
- the heat resistance (effectiveness and wear resistance) of the friction material is further improved.
- the upper limit of the titanate content is not particularly limited, and the total content of the inorganic filler including monoclinic zirconium oxide and magnesium hydroxide is the content of the inorganic filler adopted in the technical field. It may be adjusted as appropriate so that. The higher the titanate content, the more the heat resistance of the friction material described above is improved, so it is preferable.
- the particle size of the inorganic filler different from monoclinic zirconium oxide and magnesium hydroxide is not particularly limited, and inorganic substances having an average particle size commonly employed in the technical field can be preferably used.
- the friction material composition of this embodiment may further contain a lubricant to the extent that the effects of the present invention are not impaired.
- the lubricant is not particularly limited, and any lubricant known in the technical field can be preferably used.
- Specific examples of the lubricant include coke, graphite, carbon black, graphite, metal sulfide, and the like.
- metal sulfides include tin sulfide, antimony trisulfide, molybdenum disulfide, bismuth sulfide, iron sulfide, zinc sulfide, and tungsten sulfide. These lubricants can be used alone or in combination.
- the content of the lubricant is not particularly limited, and can be a content commonly employed in the technical field.
- the friction material composition of this embodiment can be manufactured by a manufacturing method including a mixing step of blending the above-mentioned friction material raw materials and mixing them.
- the mixing step is preferably a step of mixing powdered friction material raw materials.
- the mixing method and mixing conditions in the mixing step are not particularly limited as long as the friction material raw materials can be mixed uniformly, and methods known in the technical field can be adopted.
- the friction material raw materials may be mixed at room temperature for about 10 minutes using a known mixer such as a Fenschel mixer or a Loedige mixer.
- the mixture of friction material raw materials may be cooled and mixed using a known cooling method so as not to increase the temperature of the friction material raw materials being mixed.
- Friction material> A friction material according to one embodiment of the present invention is formed by molding a friction material composition according to one embodiment of the present invention. The effects, uses, etc. of the friction material of this embodiment are as described for one embodiment of the friction material composition of the present invention, so they will not be repeated here.
- the friction material of this embodiment can be manufactured by a manufacturing method including a molding step of molding the friction material composition according to one embodiment of the present invention.
- the molding method and molding conditions in the molding step are not particularly limited as long as one embodiment of the friction material composition of the present invention can be molded into a predetermined shape, and methods known in the technical field can be adopted.
- one embodiment of the friction material composition of the present invention can be molded by compacting with a press or the like.
- Examples of the press forming method include a hot press method in which an embodiment of the friction material composition of the present invention is heated and compacted, and a hot press method in which an embodiment of the friction material composition of the present invention is compacted at room temperature without heating.
- the molding temperature is 140°C or higher and 200°C or lower (preferably 160°C)
- the molding pressure is 10 MPa or higher and 40 MPa or lower (preferably 20 MPa)
- the molding time is 3 minutes.
- the present invention can be achieved by setting the molding pressure to 50 MPa or more and 200 MPa or less (preferably 100 MPa) and the molding time to 5 seconds or more and 60 seconds or less (preferably 15 seconds).
- One embodiment of the friction material composition can be formed into a friction material.
- a polishing step may be performed to polish the surface of the friction material to form a friction surface.
- Friction member> A friction member using the friction material according to one embodiment of the present invention as a friction surface is also included in the scope of the present invention.
- the friction member may have a configuration including only one embodiment of the friction material of the present invention, or a configuration in which a plate-like member such as a metal plate as a back plate and one embodiment of the friction material of the present invention are integrated. .
- the effects, uses, etc. of the friction member of this embodiment are as described for one embodiment of the friction material composition of the present invention, so they will not be repeated here.
- the friction member of this embodiment has a structure in which a plate-like member and one embodiment of the friction material of the present invention are integrated, one embodiment of the friction material of the present invention and the plate-like member are subjected to a clamping process, and then, One embodiment of the friction material of the present invention and the plate-like member can be bonded together by heat treatment.
- the conditions for the clamping treatment are not particularly limited, but are, for example, 180° C., 1 MPa, and 10 minutes. Further, the conditions for the heat treatment after the clamping treatment are also not particularly limited, but are, for example, 150° C. or more and 250° C. or less, 5 minutes or more and 180 minutes or less, preferably 230° C. and 3 hours.
- the friction material composition according to aspect 1 of the present invention is a friction material composition in which the content of copper in the friction material composition is less than 0.5% by mass as a copper element, and in which hydroxide is used as an inorganic filler.
- the friction material composition contains magnesium and monoclinic zirconium oxide, and the content of the magnesium hydroxide in the friction material composition is 0.5% by mass or more and 10% by mass or less, and The content of oblique crystal zirconium oxide is 5% by mass or more and 35% by mass or less.
- the copper content is less than 0.5% by mass as a copper element
- the effectiveness and wear resistance during high-speed braking in high temperature ranges are improved compared to conventional friction materials. It is possible to provide a friction material that has excellent and sufficient wear resistance even in a commonly used temperature range, and also has sufficient rust prevention properties on the contact surface with the friction facing material.
- the friction material composition according to Aspect 2 of the present invention may be configured to include a non-vulcanized elastomer as the organic filler in Aspect 1 above.
- the effect is that the wear resistance and rust prevention properties in the normal temperature range are further improved.
- the content of the magnesium hydroxide in the friction material composition is 0.8% by mass or more and 5% by mass or less.
- the content of the monoclinic zirconium oxide in the friction material composition may be 20% by mass or more and 30% by mass or less.
- the friction material according to Aspect 4 of the present invention is formed by molding the friction material composition according to any one of Aspects 1 to 3 above.
- Example 1 ⁇ Preparation of brake pad> Each raw material was blended according to the blending ratio shown in Table 1, and mixed at room temperature (20° C.) for about 10 minutes using a Loedige mixer to obtain a friction material composition. Note that the unit of the blending amount of each raw material in Table 1 is mass % in the friction material composition.
- a molded article was obtained by heating and compacting the friction material composition using a hot press method using a molding press.
- the molding conditions for the hot press method were as follows: Molding temperature: 160°C Molding pressure: 20MPa Molding time: 10 minutes.
- the surface of the obtained molded article was polished using a polishing machine to form a friction surface to obtain a friction material.
- a brake pad of Example 1 was prepared using this friction material, and a high temperature test and a driving simulation test were conducted.
- the thickness of the friction material was 12.5 mm, and the projected area of the friction material was 55 cm 2 .
- Example 2 to 9 Brake pads of Examples 2 to 9 were produced in the same manner as in Example 1, except that each raw material was blended according to the blending ratio shown in Table 1.
- Comparative Examples 1 to 12 Brake pads of Comparative Examples 1 to 12 were produced in the same manner as in Example 1, except that each raw material was blended according to the blending ratio shown in Table 2.
- the AMS fade test was conducted on (A) brake pads that have not been used since manufacture (new) and (B) brake pads that have a history of running on the market. "(B) Brake pads with a history of running on the market" are assumed to be in a state of advanced wear and a state of being exposed to rain. Specifically, a total of 15 L of water was poured over the brake pads and rotor after the new test for 1 minute, and then the same test as for the new brake pads was conducted. The maximum rotor temperature for each test was 650-670°C.
- the lowest coefficient of friction during the AMS fade test was measured by the following method. (Measurement method of minimum friction coefficient) Using the lowest torque during one braking, the friction coefficient of each braking was calculated using the formula described in JIS D 0106. The lowest friction coefficient in the test was defined as the lowest friction coefficient.
- the measurement results of the lowest coefficient of friction were evaluated on a five-point scale from 1 to 5 according to the criteria shown below.
- the minimum friction coefficient of the brake pad to be evaluated is 10% or more compared to the minimum friction coefficient of the brake pad of Comparative Example 1.
- the wear amount of the brake pad after the AMS fade test was measured by the following method. (Method of measuring wear amount) JASO C427 6. The amount of wear was measured according to the measurement method.
- pad wear amount was measured at 8 locations for each brake pad, and the average value was defined as the "pad average wear amount.”
- the average wear amount of the brake pad to be evaluated is 10% or more compared to the average wear amount of the brake pad of Comparative Example 1. If the average wear amount of the brake pad to be evaluated increased by 10% or more compared to the average wear amount of the brake pad of Comparative Example 1, it was evaluated as "deterioration”. If the increase or decrease in the average wear amount of the brake pad to be evaluated was less than 10% with respect to the average wear amount of the brake pad of Comparative Example 1, it was evaluated as the same or equivalent to Comparative Example 1.
- pad thickness (mm) is the thickness of the brake pad before the LACT simulation test
- pad average wear amount (mm) is the average wear amount of the brake pad before the LACT simulation test.
- the measurement method is JASO C427 6. According to the measurement method.
- the driving simulation wear test was also conducted using the brake pads of Examples 1 to 9 and Comparative Examples 1 to 12. Tests were conducted for each brake pad that had a history of running. "(B) Brake pads with a history of running on the market" were subjected to the same test as new brake pads after a total of 15 L of water was poured over the brake pads and rotor for 1 minute after testing as new brake pads. The average rotor temperature for each test was 100-200°C.
- the estimated pad life of the brake pad to be evaluated is 10% or more of the pad estimated life of the brake pad of Comparative Example 1. If the estimated pad life of the brake pad to be evaluated decreased by 10% or more compared to the estimated pad life of the brake pad of Comparative Example 1, it was evaluated as "deterioration”. If the increase or decrease in the estimated pad life of the brake pad to be evaluated was less than 10% with respect to the estimated pad life of the brake pad of Comparative Example 1, it was evaluated as the same or equivalent to Comparative Example 1.
- the degree of pad adhesion due to rust was evaluated on a five-point scale from 1 to 5 according to the criteria shown below.
- the rust fixing force of the brake pad to be evaluated is 15% or more compared to the rust fixing force of the brake pad of Comparative Example 1.
- the brake pads of Examples 1 to 9 contain specific amounts of magnesium hydroxide and monoclinic zirconium oxide as inorganic fillers, so that they are more effective at high temperatures than the brake pad of Comparative Example 1. It has excellent effectiveness and wear resistance during high-speed braking, and has sufficient wear resistance even in the normal temperature range, and has sufficient rust prevention on the contact surface with the friction facing material. was confirmed. Furthermore, from a comparison between Examples 1 to 8 and Example 9, it was found that by blending non-vulcanized rubber as the non-vulcanized elastomer, the wear resistance and rust prevention properties in the temperature range of normal use are further improved. confirmed.
- the monoclinic zirconium oxide in the friction material fuses with magnesium oxide (magnesium hydroxide in the friction material is changed by dehydration) due to the high heat generated by high-speed braking in a high temperature range, and becomes stabilized zirconium oxide. Become.
- the stabilized zirconium oxide film formed on the friction surface protects the friction surface, thereby improving the wear resistance in the high temperature range and, in turn, improving the coefficient of friction ( ⁇ ) in the high temperature range.
- the brake pad of Comparative Example 12 in which stabilized zirconium oxide was blended instead of monoclinic zirconium oxide, had deteriorated wear resistance in the normal temperature range. This is thought to be because stabilized zirconium oxide has a high Mohs hardness, which makes it highly aggressive and causes wear.
- the monoclinic zirconium oxide and magnesium hydroxide blended into the friction material composition react with the high heat generated by high-speed braking in a high temperature range, resulting in a stabilized zirconium oxide coating being formed on the friction surface.
- Appropriate formation is considered to be important in achieving both improvement in wear resistance and rust prevention in the normal temperature range and improvement in high-speed braking effectiveness and wear resistance in the high-temperature range.
- the friction material composition and friction material according to one embodiment of the present invention can be suitably used in a friction member in a braking device for a vehicle such as an automobile.
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Abstract
A friction material composition in which the content of copper therein in terms of elemental copper is less than 0.5 mass%. Specific amounts of each of magnesium hydroxide and monoclinic zirconium oxide are included as an inorganic filler.
Description
本発明は摩擦材組成物および摩擦材に関する。
The present invention relates to a friction material composition and a friction material.
ディスクブレーキ、ドラムブレーキ等の制動装置のディスクブレーキパッドおよびブレーキシューには摩擦材が使用されている。
Friction materials are used in disc brake pads and brake shoes of braking devices such as disc brakes and drum brakes.
特許文献１には、摩擦材組成物中に元素としての銅を含まない、または銅の含有量が銅元素として０．５質量％以下である組成において、無機充填材として金属硫化物を含有するとともに、無機充填材として還元剤を含有する摩擦材組成物が記載されている。
Patent Document 1 discloses that a friction material composition that does not contain copper as an element or has a copper content of 0.5% by mass or less as an elemental copper contains a metal sulfide as an inorganic filler. Additionally, a friction material composition containing a reducing agent as an inorganic filler is described.
特許文献２には、熱硬化性樹脂との親和性を高める表面処理を施した非繊維状水酸化マグネシウム粉体を５～７５体積％含む熱硬化性樹脂よりなる摩擦材が記載されている。
Patent Document 2 describes a friction material made of a thermosetting resin containing 5 to 75% by volume of non-fibrous magnesium hydroxide powder that has been subjected to a surface treatment to increase its affinity with the thermosetting resin.
特許文献３には、銅成分を含有しないＮＡＯ材の摩擦材組成物が、無機摩擦調整材として平均粒子径が１～８μｍの単斜晶の酸化ジルコニウムを摩擦材組成物全量に対し１０～４０重量％と、炭素質系潤滑材として弾性黒鉛化カーボンを摩擦材組成物全量に対し１．５重量％以上と、か焼コークスを前記弾性黒鉛化カーボンと合計で摩擦材組成物全量に対し２～８重量％、且つ前記弾性黒鉛化カーボンと前記か焼コークスの重量比率が４：６～８：２となるように含有することが記載されている。
Patent Document 3 discloses that a friction material composition of NAO material that does not contain a copper component contains monoclinic zirconium oxide with an average particle size of 1 to 8 μm as an inorganic friction modifier in an amount of 10 to 40% based on the total amount of the friction material composition. 1.5% by weight or more of elastic graphitized carbon as a carbonaceous lubricant based on the total amount of the friction material composition, and 2% or more of calcined coke with the elastic graphitized carbon based on the total amount of the friction material composition. It is described that the elastic graphitized carbon and the calcined coke are contained at a weight ratio of 4:6 to 8:2.
しかしながら、上述のような従来技術の摩擦材は、高温域での高速制動時の効きおよび耐摩耗性が十分ではない。また、ディスクロータやブレーキドラムなどの摩擦対面材との接触面における防錆性も低い。このように、従来技術の摩擦材には、改善の余地がある。
However, the friction materials of the prior art as described above do not have sufficient effectiveness and wear resistance during high-speed braking in a high temperature range. Moreover, the rust prevention property on the contact surface with friction facing materials such as disc rotors and brake drums is also low. As described above, there is room for improvement in the conventional friction materials.
本発明の一態様は、高温域での高速制動時の効きおよび耐摩耗性に優れ、且つ常用の温度域においても十分な耐摩耗性を有し、さらに摩擦対面材との接触面に十分な防錆性を有する摩擦材を提供することを目的とする。
One embodiment of the present invention has excellent effectiveness and wear resistance during high-speed braking in a high temperature range, has sufficient wear resistance even in a normal temperature range, and has sufficient wear resistance on the contact surface with the friction facing material. The purpose of the present invention is to provide a friction material having rust prevention properties.
本発明者らは、上記の課題を解決するために鋭意検討した結果、摩擦材組成物中の銅の含有量が銅元素として０．５質量％未満である組成において、無機充填材として水酸化マグネシウムおよび単斜晶酸化ジルコニウムを特定量含む摩擦材は、高温域での高速制動時の効きおよび耐摩耗性に優れ、且つ市街地走行時のような常用の温度域においても十分な耐摩耗性を有し、さらに摩擦対面材との接触面に十分な防錆性を有することを初めて見出し、本発明を完成させるに至った。すなわち、本発明の一態様に係る摩擦材組成物は、摩擦材組成物中の銅の含有量が銅元素として０．５質量％未満である摩擦材組成物であり、無機充填材として、水酸化マグネシウムおよび単斜晶酸化ジルコニウムを含み、前記摩擦材組成物中の前記水酸化マグネシウムの含有量は、０．５質量％以上、１０質量％以下であり、且つ前記摩擦材組成物中の前記単斜晶酸化ジルコニウムの含有量は、５質量％以上、３５質量％以下である構成である。
As a result of intensive studies to solve the above problems, the present inventors found that in a composition in which the content of copper in the friction material composition is less than 0.5% by mass as a copper element, hydroxide is used as an inorganic filler. Friction materials containing specific amounts of magnesium and monoclinic zirconium oxide have excellent wear resistance and effectiveness during high-speed braking in high-temperature ranges, and have sufficient wear resistance even in normal temperature ranges such as when driving around town. It was discovered for the first time that the contact surface with the friction facing material has sufficient rust prevention properties, and this led to the completion of the present invention. That is, the friction material composition according to one embodiment of the present invention is a friction material composition in which the content of copper in the friction material composition is less than 0.5% by mass as a copper element, and the friction material composition contains water as an inorganic filler. The friction material composition contains magnesium oxide and monoclinic zirconium oxide, and the content of the magnesium hydroxide in the friction material composition is 0.5% by mass or more and 10% by mass or less, and The content of monoclinic zirconium oxide is 5% by mass or more and 35% by mass or less.
本発明の一態様によれば、環境負荷の高い銅の含有量が銅元素として０．５質量％未満でありながら、高温域での高速制動時の効きおよび耐摩耗性に優れ、且つ常用の温度域においても十分な耐摩耗性を有し、さらに摩擦対面材との接触面に十分な防錆性を有する摩擦材を提供することができる。
According to one aspect of the present invention, the content of copper, which has a high environmental impact, is less than 0.5% by mass as a copper element, yet it has excellent effectiveness during high-speed braking in a high temperature range and wear resistance, and is suitable for regular use. It is possible to provide a friction material that has sufficient wear resistance even in a temperature range and also has sufficient rust prevention on the contact surface with the friction facing material.
＜１．摩擦材組成物＞
本発明の一態様に係る摩擦材組成物は、摩擦材組成物中の銅の含有量が銅元素として０．５質量％未満である摩擦材組成物であり、無機充填材として、水酸化マグネシウムおよび単斜晶酸化ジルコニウムを含み、前記摩擦材組成物中の前記水酸化マグネシウムの含有量は、０．５質量％以上、１０質量％以下であり、且つ前記摩擦材組成物中の前記単斜晶酸化ジルコニウムの含有量は、５質量％以上、３５質量％以下である。本態様の摩擦材組成物は、上述の成分を含む摩擦材原料を配合したものが意図される。本態様の摩擦材組成物は、後述する摩擦材を成形するために用いることができる。 <1. Friction material composition>
A friction material composition according to one aspect of the present invention is a friction material composition in which the content of copper in the friction material composition is less than 0.5% by mass as a copper element, and magnesium hydroxide is used as an inorganic filler. and monoclinic zirconium oxide, the content of the magnesium hydroxide in the friction material composition is 0.5% by mass or more and 10% by mass or less, and the monoclinic zirconium oxide in the friction material composition is The content of crystalline zirconium oxide is 5% by mass or more and 35% by mass or less. The friction material composition of this embodiment is intended to be a mixture of friction material raw materials containing the above-mentioned components. The friction material composition of this embodiment can be used to mold the friction material described below.
本発明の一態様に係る摩擦材組成物は、摩擦材組成物中の銅の含有量が銅元素として０．５質量％未満である摩擦材組成物であり、無機充填材として、水酸化マグネシウムおよび単斜晶酸化ジルコニウムを含み、前記摩擦材組成物中の前記水酸化マグネシウムの含有量は、０．５質量％以上、１０質量％以下であり、且つ前記摩擦材組成物中の前記単斜晶酸化ジルコニウムの含有量は、５質量％以上、３５質量％以下である。本態様の摩擦材組成物は、上述の成分を含む摩擦材原料を配合したものが意図される。本態様の摩擦材組成物は、後述する摩擦材を成形するために用いることができる。 <1. Friction material composition>
A friction material composition according to one aspect of the present invention is a friction material composition in which the content of copper in the friction material composition is less than 0.5% by mass as a copper element, and magnesium hydroxide is used as an inorganic filler. and monoclinic zirconium oxide, the content of the magnesium hydroxide in the friction material composition is 0.5% by mass or more and 10% by mass or less, and the monoclinic zirconium oxide in the friction material composition is The content of crystalline zirconium oxide is 5% by mass or more and 35% by mass or less. The friction material composition of this embodiment is intended to be a mixture of friction material raw materials containing the above-mentioned components. The friction material composition of this embodiment can be used to mold the friction material described below.
〔特徴〕
本態様の摩擦材組成物は、摩擦材組成物中の銅の含有量が銅元素として０．５質量％未満であるので環境に優しい。さらに、無機充填材として、水酸化マグネシウムおよび単斜晶酸化ジルコニウムを特定量含有するため、銅の含有量が銅元素として０．５質量％未満でありながら、高温域での高速制動時の効きおよび耐摩耗性に優れ、且つ常用の温度域においても十分な耐摩耗性を有し、さらに摩擦対面材との接触面に十分な防錆性を有する摩擦材を提供できるという優れた効果を奏する。 〔Features〕
The friction material composition of this embodiment is environmentally friendly because the content of copper in the friction material composition is less than 0.5% by mass as a copper element. Furthermore, because it contains specific amounts of magnesium hydroxide and monoclinic zirconium oxide as inorganic fillers, the copper content is less than 0.5% by mass as an elemental copper, but the effectiveness during high-speed braking at high temperatures is improved. It has the excellent effect of being able to provide a friction material that has excellent abrasion resistance, has sufficient abrasion resistance even in the normal temperature range, and has sufficient rust prevention properties on the contact surface with the friction face material. .
本態様の摩擦材組成物は、摩擦材組成物中の銅の含有量が銅元素として０．５質量％未満であるので環境に優しい。さらに、無機充填材として、水酸化マグネシウムおよび単斜晶酸化ジルコニウムを特定量含有するため、銅の含有量が銅元素として０．５質量％未満でありながら、高温域での高速制動時の効きおよび耐摩耗性に優れ、且つ常用の温度域においても十分な耐摩耗性を有し、さらに摩擦対面材との接触面に十分な防錆性を有する摩擦材を提供できるという優れた効果を奏する。 〔Features〕
The friction material composition of this embodiment is environmentally friendly because the content of copper in the friction material composition is less than 0.5% by mass as a copper element. Furthermore, because it contains specific amounts of magnesium hydroxide and monoclinic zirconium oxide as inorganic fillers, the copper content is less than 0.5% by mass as an elemental copper, but the effectiveness during high-speed braking at high temperatures is improved. It has the excellent effect of being able to provide a friction material that has excellent abrasion resistance, has sufficient abrasion resistance even in the normal temperature range, and has sufficient rust prevention properties on the contact surface with the friction face material. .
本態様の摩擦材組成物を用いた摩擦材は、高温域（例えば６５０℃以上）での高速制動時の耐摩耗性が向上することで、高温域での高速制動時の効き向上も同時に達成することができる。また、高温域での高速制動時の耐摩耗性が向上するということは、摩擦面の摩擦材強度が向上しているとも言え、これにより摩擦材の耐熱効果の向上も期待できる。
The friction material using the friction material composition of this embodiment has improved wear resistance during high-speed braking in a high-temperature range (for example, 650°C or higher), thereby simultaneously achieving improved effectiveness during high-speed braking in a high-temperature range. can do. Furthermore, the improvement in wear resistance during high-speed braking in a high-temperature range can also be said to be an improvement in the strength of the friction material on the friction surface, which can also be expected to improve the heat resistance effect of the friction material.
また、本態様の摩擦材組成物を用いた摩擦材は、高温域での高速制動時の耐摩耗性と常用の温度域（例えば、１００～２００℃）での耐摩耗性とを両立させることができるため、従来の摩擦材と比較して長寿命であるという優れた効果を奏する。さらには、本態様の摩擦材組成物を用いた摩擦材は、耐摩耗性に優れることで、摩耗により放出される粉塵が少ない。その結果、粉塵によってホイールが汚れにくく、且つ環境負荷が高いＰＭ２．５やＰＭ１０の排出量が少ないという優れた効果を奏する。
Further, a friction material using the friction material composition of this embodiment has both wear resistance during high-speed braking in a high temperature range and wear resistance in a commonly used temperature range (for example, 100 to 200°C). Because of this, it has an excellent effect of having a longer life compared to conventional friction materials. Furthermore, the friction material using the friction material composition of this embodiment has excellent wear resistance, and thus releases less dust due to wear. As a result, excellent effects are achieved in that the wheels are less likely to be contaminated by dust and the amount of PM2.5 and PM10, which have a high environmental impact, is emitted in a small amount.
また、本態様の摩擦材組成物を用いた摩擦材は、摩擦対面材との接触面に十分な防錆性を有するため、摩擦対面材との接触面で発生した錆によって摩擦材が摩擦対面材と固着しにくい。その結果、発車時の異音発生や摩擦材の表面剥離などの問題が生じにくいという優れた効果を奏する。
In addition, since the friction material using the friction material composition of this embodiment has sufficient rust prevention properties on the contact surface with the friction surface material, rust generated on the contact surface with the friction surface material causes the friction material to Hard to stick to wood. As a result, an excellent effect is achieved in that problems such as abnormal noise generation and surface peeling of the friction material are less likely to occur when the vehicle starts.
〔用途〕
上述のような特徴を有する本態様の摩擦材組成物は、電気自動車（ＥＶ）やハイブリッド車（ＨＥＶ）用のディスクブレーキ用パッド、ドラムブレーキ用ブレーキシューの摩擦面に使用される摩擦材に用いるため摩擦材組成物として特に有用である。なぜなら、ＥＶ／ＨＥＶは、大型バッテリー搭載により従来のガソリン車と比べ車両重量が重く、高速制動時においては回生ブレーキの寄与度が低いという傾向があり、従来のガソリン車と比べて高温域での高速制動時にブレーキパッドまたはブレーキシューの温度が上がりやすく、高温に達する頻度が増加するためである。 [Application]
The friction material composition of this embodiment having the above-mentioned characteristics can be used as a friction material used for the friction surface of disc brake pads and drum brake shoes for electric vehicles (EVs) and hybrid vehicles (HEVs). Therefore, it is particularly useful as a friction material composition. This is because EVs/HEVs are heavier than conventional gasoline vehicles due to their large batteries, and the contribution of regenerative braking during high-speed braking tends to be low. This is because the temperature of the brake pad or brake shoe tends to rise during high-speed braking, increasing the frequency at which the brake pad or brake shoe reaches high temperatures.
上述のような特徴を有する本態様の摩擦材組成物は、電気自動車（ＥＶ）やハイブリッド車（ＨＥＶ）用のディスクブレーキ用パッド、ドラムブレーキ用ブレーキシューの摩擦面に使用される摩擦材に用いるため摩擦材組成物として特に有用である。なぜなら、ＥＶ／ＨＥＶは、大型バッテリー搭載により従来のガソリン車と比べ車両重量が重く、高速制動時においては回生ブレーキの寄与度が低いという傾向があり、従来のガソリン車と比べて高温域での高速制動時にブレーキパッドまたはブレーキシューの温度が上がりやすく、高温に達する頻度が増加するためである。 [Application]
The friction material composition of this embodiment having the above-mentioned characteristics can be used as a friction material used for the friction surface of disc brake pads and drum brake shoes for electric vehicles (EVs) and hybrid vehicles (HEVs). Therefore, it is particularly useful as a friction material composition. This is because EVs/HEVs are heavier than conventional gasoline vehicles due to their large batteries, and the contribution of regenerative braking during high-speed braking tends to be low. This is because the temperature of the brake pad or brake shoe tends to rise during high-speed braking, increasing the frequency at which the brake pad or brake shoe reaches high temperatures.
本態様の摩擦材組成物の用途はＥＶ／ＨＥＶ用に特に限定されるものではなく、二輪車を含む車両全般において採用されるディスクブレーキ用パッド、ドラムブレーキ用ブレーキシュー等の摩擦面に使用される摩擦材に好適に用いることができる。
The application of the friction material composition of this embodiment is not particularly limited to EV/HEV, but can be used for friction surfaces of disc brake pads, drum brake brake shoes, etc. employed in general vehicles including motorcycles. It can be suitably used as a friction material.
〔原料〕
以下に、本態様の摩擦材組成物に含まれている原料（摩擦材原料）について説明する。 〔material〕
The raw materials (friction material raw materials) contained in the friction material composition of this embodiment will be explained below.
以下に、本態様の摩擦材組成物に含まれている原料（摩擦材原料）について説明する。 〔material〕
The raw materials (friction material raw materials) contained in the friction material composition of this embodiment will be explained below.
（銅）
本発明の一態様に係る摩擦材組成物は、摩擦材組成物中の銅の含有量が銅元素として０．５質量％未満である。本発明の一態様に係る摩擦材組成物は、環境有害性の高い銅および銅合金の含有量が非常に少ないため、環境に優しい摩擦材を提供できるという効果を奏する。環境により優しい摩擦材を提供する観点から、摩擦材組成物中の銅の含有量は、０質量％（銅フリー）であることがより好ましい。本発明の一態様に係る摩擦材組成物中に含まれる銅は、繊維基材として添加された銅繊維に由来するものであり得る。 (copper)
In the friction material composition according to one aspect of the present invention, the content of copper in the friction material composition is less than 0.5% by mass as a copper element. The friction material composition according to one embodiment of the present invention has a very low content of copper and copper alloy, which are highly harmful to the environment, and therefore has the effect of providing an environmentally friendly friction material. From the viewpoint of providing a friction material that is more environmentally friendly, the content of copper in the friction material composition is more preferably 0% by mass (copper-free). Copper contained in the friction material composition according to one embodiment of the present invention may be derived from copper fibers added as a fiber base material.
本発明の一態様に係る摩擦材組成物は、摩擦材組成物中の銅の含有量が銅元素として０．５質量％未満である。本発明の一態様に係る摩擦材組成物は、環境有害性の高い銅および銅合金の含有量が非常に少ないため、環境に優しい摩擦材を提供できるという効果を奏する。環境により優しい摩擦材を提供する観点から、摩擦材組成物中の銅の含有量は、０質量％（銅フリー）であることがより好ましい。本発明の一態様に係る摩擦材組成物中に含まれる銅は、繊維基材として添加された銅繊維に由来するものであり得る。 (copper)
In the friction material composition according to one aspect of the present invention, the content of copper in the friction material composition is less than 0.5% by mass as a copper element. The friction material composition according to one embodiment of the present invention has a very low content of copper and copper alloy, which are highly harmful to the environment, and therefore has the effect of providing an environmentally friendly friction material. From the viewpoint of providing a friction material that is more environmentally friendly, the content of copper in the friction material composition is more preferably 0% by mass (copper-free). Copper contained in the friction material composition according to one embodiment of the present invention may be derived from copper fibers added as a fiber base material.
（水酸化マグネシウム）
本発明の一態様に係る摩擦材組成物は、無機充填材の１種として、摩擦材組成物１００質量％に対して０．５質量％以上、１０質量％以下の水酸化マグネシウムを含有している。 (magnesium hydroxide)
The friction material composition according to one aspect of the present invention contains magnesium hydroxide in an amount of 0.5% by mass or more and 10% by mass or less based on 100% by mass of the friction material composition, as one type of inorganic filler. There is.
本発明の一態様に係る摩擦材組成物は、無機充填材の１種として、摩擦材組成物１００質量％に対して０．５質量％以上、１０質量％以下の水酸化マグネシウムを含有している。 (magnesium hydroxide)
The friction material composition according to one aspect of the present invention contains magnesium hydroxide in an amount of 0.5% by mass or more and 10% by mass or less based on 100% by mass of the friction material composition, as one type of inorganic filler. There is.
（水酸化マグネシウムの作用および効果）
（ｉ）常用の温度域での耐摩耗性および防錆性の向上
水酸化マグネシウムは、モース硬度が２～３であり、ディスクロータやブレーキドラムなどの摩擦対面材との摩擦で崩れやすい。このため、摩擦面にアルカリ性の水酸化マグネシウムが均一に広がりやすい。その結果、水酸化マグネシウムを含む摩擦材は、防錆効果が高い。 (Actions and effects of magnesium hydroxide)
(i) Improved abrasion resistance and rust prevention in the normal temperature range Magnesium hydroxide has a Mohs hardness of 2 to 3, and is easily crumbled by friction with friction facing materials such as disc rotors and brake drums. Therefore, alkaline magnesium hydroxide tends to spread uniformly on the friction surface. As a result, friction materials containing magnesium hydroxide have a high rust prevention effect.
（ｉ）常用の温度域での耐摩耗性および防錆性の向上
水酸化マグネシウムは、モース硬度が２～３であり、ディスクロータやブレーキドラムなどの摩擦対面材との摩擦で崩れやすい。このため、摩擦面にアルカリ性の水酸化マグネシウムが均一に広がりやすい。その結果、水酸化マグネシウムを含む摩擦材は、防錆効果が高い。 (Actions and effects of magnesium hydroxide)
(i) Improved abrasion resistance and rust prevention in the normal temperature range Magnesium hydroxide has a Mohs hardness of 2 to 3, and is easily crumbled by friction with friction facing materials such as disc rotors and brake drums. Therefore, alkaline magnesium hydroxide tends to spread uniformly on the friction surface. As a result, friction materials containing magnesium hydroxide have a high rust prevention effect.
また、水酸化マグネシウムは、水への溶解度が小さく、水濡れによりパッド（摩擦面など）からアルカリの消失が起こりにくい。このため、他のアルカリ系材料よりも防錆効果が長持ちする。その結果、水酸化マグネシウムを含む摩擦材は、梅雨の時期のような雨の中にさらされた状態や古いパッドの様な摩耗が進んだ状態でも防錆効果が持続する。
Furthermore, magnesium hydroxide has low solubility in water, and alkali is less likely to disappear from the pad (friction surface, etc.) due to water wetting. For this reason, the rust prevention effect lasts longer than other alkaline materials. As a result, friction materials containing magnesium hydroxide maintain their anti-corrosion effect even when exposed to rain during the rainy season or when worn, such as with old pads.
水酸化マグネシウムのｐＨは１０．５であり、摩擦材に結合材として含まれる樹脂の分解を促進するほどのｐＨの高さではない。このため、水酸化マグネシウムを含む摩擦材は、樹脂の分解による強度低下が起こりにくい。その結果、パッドの耐摩耗性が良好となる。
The pH of magnesium hydroxide is 10.5, which is not high enough to promote the decomposition of the resin contained as a binder in the friction material. For this reason, friction materials containing magnesium hydroxide are less likely to lose strength due to decomposition of the resin. As a result, the pad has good wear resistance.
（ｉｉ）高温域での高速制動時の効きおよび耐摩耗性の向上
水酸化マグネシウムは、３００～４００℃において脱水吸熱による耐熱効果を有している。摩擦面に均一に広がった水酸化マグネシウムは、脱水により酸化マグネシウムへと変化する。酸化マグネシウムは、高温域での高速制動（高負荷制動）により発生する高熱によって後述する単斜晶酸化ジルコニウムと融合することで、安定化酸化ジルコニウムの被膜形成に寄与する。安定化酸化ジルコニウムは、安定した被膜を作り易く、且つ耐熱性に優れる。安定化酸化ジルコニウムの被膜は、摩擦面を保護することによって耐摩耗性を向上させ、ひいては摩擦係数（μ）を向上させる。 (ii) Improved effectiveness and wear resistance during high-speed braking in high-temperature ranges Magnesium hydroxide has a heat-resistant effect by absorbing heat from dehydration at 300 to 400°C. Magnesium hydroxide spread uniformly on the friction surface changes to magnesium oxide through dehydration. Magnesium oxide contributes to the formation of a stabilized zirconium oxide film by fusing with monoclinic zirconium oxide, which will be described later, due to the high heat generated by high-speed braking (high-load braking) in a high-temperature range. Stabilized zirconium oxide is easy to form a stable film and has excellent heat resistance. The stabilized zirconium oxide coating improves wear resistance by protecting the friction surfaces and thus improves the coefficient of friction (μ).
水酸化マグネシウムは、３００～４００℃において脱水吸熱による耐熱効果を有している。摩擦面に均一に広がった水酸化マグネシウムは、脱水により酸化マグネシウムへと変化する。酸化マグネシウムは、高温域での高速制動（高負荷制動）により発生する高熱によって後述する単斜晶酸化ジルコニウムと融合することで、安定化酸化ジルコニウムの被膜形成に寄与する。安定化酸化ジルコニウムは、安定した被膜を作り易く、且つ耐熱性に優れる。安定化酸化ジルコニウムの被膜は、摩擦面を保護することによって耐摩耗性を向上させ、ひいては摩擦係数（μ）を向上させる。 (ii) Improved effectiveness and wear resistance during high-speed braking in high-temperature ranges Magnesium hydroxide has a heat-resistant effect by absorbing heat from dehydration at 300 to 400°C. Magnesium hydroxide spread uniformly on the friction surface changes to magnesium oxide through dehydration. Magnesium oxide contributes to the formation of a stabilized zirconium oxide film by fusing with monoclinic zirconium oxide, which will be described later, due to the high heat generated by high-speed braking (high-load braking) in a high-temperature range. Stabilized zirconium oxide is easy to form a stable film and has excellent heat resistance. The stabilized zirconium oxide coating improves wear resistance by protecting the friction surfaces and thus improves the coefficient of friction (μ).
本態様の摩擦材組成物中の水酸化マグネシウムの含有量が摩擦材組成物１００質量％に対して０．５質量％以上であることにより、十分な量の水酸化マグネシウムが摩擦面に広がるため、前述の（ｉ）および（ｉｉ）の効果が十分に発現される。また、本態様の摩擦材組成物中の水酸化マグネシウムの含有量が摩擦材組成物１００質量％に対して１０質量％以下であれば、水酸化マグネシウムの脱水による体積変化の影響が小さく、摩擦材の母材強度の低下が起こりにくい。その結果、常用の温度域でのパッドの耐摩耗性が良好となり、十分な耐熱効果も得られる。
Since the content of magnesium hydroxide in the friction material composition of this embodiment is 0.5% by mass or more based on 100% by mass of the friction material composition, a sufficient amount of magnesium hydroxide spreads on the friction surface. , the effects of (i) and (ii) above are fully expressed. Further, if the content of magnesium hydroxide in the friction material composition of this embodiment is 10% by mass or less with respect to 100% by mass of the friction material composition, the effect of volume change due to dehydration of magnesium hydroxide is small, and friction The strength of the base material is less likely to decrease. As a result, the pad has good abrasion resistance in the commonly used temperature range, and a sufficient heat resistance effect can also be obtained.
（水酸化マグネシウムの好ましい含有量）
高温域での高速制動時の効きおよび耐摩耗性をより向上させる観点から、摩擦材組成物中の水酸化マグネシウムの含有量は、摩擦材組成物１００質量％に対して０．８質量％以上、５質量％以下であることが好ましい。 (Preferred content of magnesium hydroxide)
From the viewpoint of further improving the effectiveness and wear resistance during high-speed braking in a high temperature range, the content of magnesium hydroxide in the friction material composition is 0.8% by mass or more based on 100% by mass of the friction material composition. , preferably 5% by mass or less.
高温域での高速制動時の効きおよび耐摩耗性をより向上させる観点から、摩擦材組成物中の水酸化マグネシウムの含有量は、摩擦材組成物１００質量％に対して０．８質量％以上、５質量％以下であることが好ましい。 (Preferred content of magnesium hydroxide)
From the viewpoint of further improving the effectiveness and wear resistance during high-speed braking in a high temperature range, the content of magnesium hydroxide in the friction material composition is 0.8% by mass or more based on 100% by mass of the friction material composition. , preferably 5% by mass or less.
（水酸化マグネシウムの粒径）
前述の（ｉ）および（ｉｉ）の効果の発現の観点で、水酸化マグネシウムの粒径は特に限定されない。このため、摩擦材に添加される無機充填材として通常採用される粒径の水酸化マグネシウムを適宜選択することができる。但し、摩擦材組成物の製造時の取扱い性の観点からは、水酸化マグネシウムの平均粒径が２μｍ以上であることが好ましく、４μｍ以上であることがより好ましい。また、摩擦材組成物の製造時に偏りなく均一に混合することが可能となる、および制動時に水酸化マグネシウムの粒子が摩擦面から脱落しにくいために、高温域での高速制動時の効きおよび耐摩耗性の向上効果が摩擦面のどの場所でも安定して得られる等の理由から、水酸化マグネシウムの平均粒径が２０μｍ以下であることが好ましく、１５μｍ以下であることがより好ましい。 (Particle size of magnesium hydroxide)
From the viewpoint of achieving the effects (i) and (ii) described above, the particle size of magnesium hydroxide is not particularly limited. Therefore, magnesium hydroxide having a particle size that is normally employed as an inorganic filler added to friction materials can be appropriately selected. However, from the viewpoint of ease of handling during production of the friction material composition, the average particle size of magnesium hydroxide is preferably 2 μm or more, more preferably 4 μm or more. In addition, it is possible to mix the friction material composition uniformly and evenly during production, and magnesium hydroxide particles are less likely to fall off the friction surface during braking, which improves the effectiveness and durability of high-speed braking in high-temperature ranges. The average particle size of magnesium hydroxide is preferably 20 μm or less, more preferably 15 μm or less, because the effect of improving abrasion properties can be stably obtained at any location on the friction surface.
前述の（ｉ）および（ｉｉ）の効果の発現の観点で、水酸化マグネシウムの粒径は特に限定されない。このため、摩擦材に添加される無機充填材として通常採用される粒径の水酸化マグネシウムを適宜選択することができる。但し、摩擦材組成物の製造時の取扱い性の観点からは、水酸化マグネシウムの平均粒径が２μｍ以上であることが好ましく、４μｍ以上であることがより好ましい。また、摩擦材組成物の製造時に偏りなく均一に混合することが可能となる、および制動時に水酸化マグネシウムの粒子が摩擦面から脱落しにくいために、高温域での高速制動時の効きおよび耐摩耗性の向上効果が摩擦面のどの場所でも安定して得られる等の理由から、水酸化マグネシウムの平均粒径が２０μｍ以下であることが好ましく、１５μｍ以下であることがより好ましい。 (Particle size of magnesium hydroxide)
From the viewpoint of achieving the effects (i) and (ii) described above, the particle size of magnesium hydroxide is not particularly limited. Therefore, magnesium hydroxide having a particle size that is normally employed as an inorganic filler added to friction materials can be appropriately selected. However, from the viewpoint of ease of handling during production of the friction material composition, the average particle size of magnesium hydroxide is preferably 2 μm or more, more preferably 4 μm or more. In addition, it is possible to mix the friction material composition uniformly and evenly during production, and magnesium hydroxide particles are less likely to fall off the friction surface during braking, which improves the effectiveness and durability of high-speed braking in high-temperature ranges. The average particle size of magnesium hydroxide is preferably 20 μm or less, more preferably 15 μm or less, because the effect of improving abrasion properties can be stably obtained at any location on the friction surface.
水酸化マグネシウムの平均粒径は、ＪＩＳ Ｚ ８８２５「粒子径解析－レーザ解析・散乱法」により得られる体積基準の中位径（メジアン径）とする。摩擦材形成後に水酸化マグネシウムの粒子径を確認する場合は、摩擦材の断面の電子顕微鏡画像から水酸化マグネシウムに該当する粒子の平均粒径をＪＩＳ Ｚ ８８２７－１「粒子径解析－画像解析法－第１部：静的画像解析法」により体積基準の粒度分布を測定し、中位径を求めればよい。
The average particle size of magnesium hydroxide is the volume-based median diameter obtained by JIS Z 8825 "Particle size analysis - laser analysis/scattering method". When confirming the particle size of magnesium hydroxide after forming the friction material, calculate the average particle size of the particles corresponding to magnesium hydroxide from an electron microscope image of the cross section of the friction material using JIS Z 8827-1 "Particle size analysis - image analysis method. - Part 1: Static image analysis method" to measure the volume-based particle size distribution and find the median diameter.
（単斜晶酸化ジルコニウム）
本発明の一態様に係る摩擦材組成物は、無機充填材の１種として、摩擦材組成物１００質量％に対して５質量％以上、３５質量％以下の単斜晶酸化ジルコニウムを含有している。「単斜晶酸化ジルコニウム」は、結晶系が単斜晶系である酸化ジルコニウムを指す。酸化ジルコニウムは、温度によって結晶系が転移する。室温（２０℃）では単斜晶系であり、温度を上げていくと、１１７０℃で正方晶へ、２３７０℃で立方晶へと結晶構造が変化していく。相転移は体積変化を伴う。 (monoclinic zirconium oxide)
The friction material composition according to one aspect of the present invention contains monoclinic zirconium oxide in an amount of 5% by mass or more and 35% by mass or less based on 100% by mass of the friction material composition, as one type of inorganic filler. There is. "Monoclinic zirconium oxide" refers to zirconium oxide whose crystal system is monoclinic. The crystal system of zirconium oxide undergoes a transition depending on the temperature. At room temperature (20°C), it is monoclinic, and as the temperature is raised, the crystal structure changes to tetragonal at 1170°C and cubic at 2370°C. Phase transitions are accompanied by volume changes.
本発明の一態様に係る摩擦材組成物は、無機充填材の１種として、摩擦材組成物１００質量％に対して５質量％以上、３５質量％以下の単斜晶酸化ジルコニウムを含有している。「単斜晶酸化ジルコニウム」は、結晶系が単斜晶系である酸化ジルコニウムを指す。酸化ジルコニウムは、温度によって結晶系が転移する。室温（２０℃）では単斜晶系であり、温度を上げていくと、１１７０℃で正方晶へ、２３７０℃で立方晶へと結晶構造が変化していく。相転移は体積変化を伴う。 (monoclinic zirconium oxide)
The friction material composition according to one aspect of the present invention contains monoclinic zirconium oxide in an amount of 5% by mass or more and 35% by mass or less based on 100% by mass of the friction material composition, as one type of inorganic filler. There is. "Monoclinic zirconium oxide" refers to zirconium oxide whose crystal system is monoclinic. The crystal system of zirconium oxide undergoes a transition depending on the temperature. At room temperature (20°C), it is monoclinic, and as the temperature is raised, the crystal structure changes to tetragonal at 1170°C and cubic at 2370°C. Phase transitions are accompanied by volume changes.
純粋な酸化ジルコニウムは、室温で単斜晶系が最も安定であるが、酸化マグネシウムと融合することで、立方晶が室温でも安定して存在するようになる。室温において立方晶で安定化された酸化ジルコニウムは「安定化酸化ジルコニウム」と呼ばれる。
Pure zirconium oxide is most stable in the monoclinic system at room temperature, but when fused with magnesium oxide, the cubic system becomes stable even at room temperature. Zirconium oxide stabilized in cubic form at room temperature is called "stabilized zirconium oxide."
（単斜晶酸化ジルコニウムの作用および効果）
（ｉ）常用の温度域での耐摩耗性および防錆性の向上
単斜晶酸化ジルコニウムは、安定化酸化ジルコニウムと比べて靭性が低い。このため、単斜晶酸化ジルコニウムは、非制動状態に限らず制動状態も研削性が低いため、両状態でロータ研削性が低く、摩擦面に広がった水酸化マグネシウムが失われにくい。その結果、摩擦面に広がった水酸化マグネシウムによってもたらされる防錆性が十分に発揮される。また、単斜晶酸化ジルコニウムは、安定化酸化ジルコニウムと比べて靭性が低いことにより、パッドの耐摩耗性が良好となる。 (Actions and effects of monoclinic zirconium oxide)
(i) Improved wear resistance and rust prevention in the normal temperature range Monoclinic zirconium oxide has lower toughness than stabilized zirconium oxide. Therefore, monoclinic zirconium oxide has low grindability not only in the non-braking state but also in the braking state, so the rotor grindability is low in both states, and the magnesium hydroxide spread on the friction surface is difficult to lose. As a result, the rust prevention properties provided by the magnesium hydroxide spread over the friction surface are fully exhibited. Additionally, monoclinic zirconium oxide has lower toughness than stabilized zirconium oxide, so that the pad has better wear resistance.
（ｉ）常用の温度域での耐摩耗性および防錆性の向上
単斜晶酸化ジルコニウムは、安定化酸化ジルコニウムと比べて靭性が低い。このため、単斜晶酸化ジルコニウムは、非制動状態に限らず制動状態も研削性が低いため、両状態でロータ研削性が低く、摩擦面に広がった水酸化マグネシウムが失われにくい。その結果、摩擦面に広がった水酸化マグネシウムによってもたらされる防錆性が十分に発揮される。また、単斜晶酸化ジルコニウムは、安定化酸化ジルコニウムと比べて靭性が低いことにより、パッドの耐摩耗性が良好となる。 (Actions and effects of monoclinic zirconium oxide)
(i) Improved wear resistance and rust prevention in the normal temperature range Monoclinic zirconium oxide has lower toughness than stabilized zirconium oxide. Therefore, monoclinic zirconium oxide has low grindability not only in the non-braking state but also in the braking state, so the rotor grindability is low in both states, and the magnesium hydroxide spread on the friction surface is difficult to lose. As a result, the rust prevention properties provided by the magnesium hydroxide spread over the friction surface are fully exhibited. Additionally, monoclinic zirconium oxide has lower toughness than stabilized zirconium oxide, so that the pad has better wear resistance.
（ｉｉ）高温域での高速制動時の効きおよび耐摩耗性の向上
単斜晶酸化ジルコニウムは、高温域での高速制動（高負荷制動）により発生する高熱によって酸化マグネシウム（摩擦材中の水酸化マグネシウムが脱水によって変化したもの）と融合することで、安定化酸化ジルコニウムとなる。摩擦面に形成された安定化酸化ジルコニウムの被膜は、摩擦面を保護する。また、酸化マグネシウムと反応して立方晶の安定化酸化ジルコニウムとなることで相転移に伴う体積変化が生じなくなるため、摩擦面の摩擦材強度が低下し難くなる。その結果、パッドの耐摩耗性が向上し、ひいては摩擦係数（μ）が向上する。 (ii) Improved effectiveness and wear resistance during high-speed braking in high-temperature ranges Monoclinic zirconium oxide can be used for magnesium oxide (hydroxide in friction materials) due to the high heat generated by high-speed braking (high-load braking) in high-temperature ranges. When fused with magnesium (modified by dehydration), it becomes stabilized zirconium oxide. The stabilized zirconium oxide coating formed on the friction surface protects the friction surface. Further, since it reacts with magnesium oxide to form cubic stabilized zirconium oxide, no volume change occurs due to phase transition, so the strength of the friction material on the friction surface is less likely to decrease. As a result, the wear resistance of the pad is improved, and the coefficient of friction (μ) is also improved.
単斜晶酸化ジルコニウムは、高温域での高速制動（高負荷制動）により発生する高熱によって酸化マグネシウム（摩擦材中の水酸化マグネシウムが脱水によって変化したもの）と融合することで、安定化酸化ジルコニウムとなる。摩擦面に形成された安定化酸化ジルコニウムの被膜は、摩擦面を保護する。また、酸化マグネシウムと反応して立方晶の安定化酸化ジルコニウムとなることで相転移に伴う体積変化が生じなくなるため、摩擦面の摩擦材強度が低下し難くなる。その結果、パッドの耐摩耗性が向上し、ひいては摩擦係数（μ）が向上する。 (ii) Improved effectiveness and wear resistance during high-speed braking in high-temperature ranges Monoclinic zirconium oxide can be used for magnesium oxide (hydroxide in friction materials) due to the high heat generated by high-speed braking (high-load braking) in high-temperature ranges. When fused with magnesium (modified by dehydration), it becomes stabilized zirconium oxide. The stabilized zirconium oxide coating formed on the friction surface protects the friction surface. Further, since it reacts with magnesium oxide to form cubic stabilized zirconium oxide, no volume change occurs due to phase transition, so the strength of the friction material on the friction surface is less likely to decrease. As a result, the wear resistance of the pad is improved, and the coefficient of friction (μ) is also improved.
本態様の摩擦材組成物中の単斜晶酸化ジルコニウムの含有量によって、摩擦面に形成される安定化酸化ジルコニウムの被膜の厚みが変化する。本態様の摩擦材組成物中の単斜晶酸化ジルコニウムの含有量が摩擦材組成物１００質量％に対して５質量％以上であることにより、上記（ｉｉ）の効果が発現されるために十分な厚みの安定化酸化ジルコニウムの被膜が形成される。また、本態様の摩擦材組成物中の単斜晶酸化ジルコニウムの含有量が摩擦材組成物１００質量％に対して３５質量％以下であれば、安定化酸化ジルコニウムの被膜が厚くなりすぎない。その結果、水酸化マグネシウムが安定化酸化ジルコニウムの被膜に埋もれてしまうことがないため、水酸化マグネシウムによる耐錆性の効果が十分に発現される。また、安定化酸化ジルコニウムの被膜が摩擦面から剥がれ落ち難いため、被膜厚のバラツキによって摩擦面積が小さくなり、高温域での効きが低下することを防ぐことができる。従って、上記（ｉ）の効果が十分に発現される。
The thickness of the stabilized zirconium oxide coating formed on the friction surface changes depending on the content of monoclinic zirconium oxide in the friction material composition of this embodiment. The content of monoclinic zirconium oxide in the friction material composition of this embodiment is 5% by mass or more based on 100% by mass of the friction material composition, which is sufficient for the above effect (ii) to be expressed. A film of stabilized zirconium oxide with a certain thickness is formed. Further, if the content of monoclinic zirconium oxide in the friction material composition of this embodiment is 35% by mass or less based on 100% by mass of the friction material composition, the stabilized zirconium oxide film will not become too thick. As a result, the magnesium hydroxide is not buried in the stabilized zirconium oxide coating, so that the rust-resistant effect of the magnesium hydroxide is fully exhibited. In addition, since the stabilized zirconium oxide coating is difficult to peel off from the friction surface, it is possible to prevent the friction area from becoming small due to variations in coating thickness and the effectiveness at high temperatures from decreasing. Therefore, the effect of (i) above is fully exhibited.
（単斜晶酸化ジルコニウムの好ましい含有量）
高温域での高速制動時の効きおよび耐摩耗性をより向上させる観点から、摩擦材組成物中の単斜晶酸化ジルコニウムの含有量は、摩擦材組成物１００質量％に対して２０質量％以上、３０質量％以下であることが好ましい。 (Preferred content of monoclinic zirconium oxide)
From the perspective of further improving the effectiveness and wear resistance during high-speed braking in a high temperature range, the content of monoclinic zirconium oxide in the friction material composition is 20% by mass or more based on 100% by mass of the friction material composition. , preferably 30% by mass or less.
高温域での高速制動時の効きおよび耐摩耗性をより向上させる観点から、摩擦材組成物中の単斜晶酸化ジルコニウムの含有量は、摩擦材組成物１００質量％に対して２０質量％以上、３０質量％以下であることが好ましい。 (Preferred content of monoclinic zirconium oxide)
From the perspective of further improving the effectiveness and wear resistance during high-speed braking in a high temperature range, the content of monoclinic zirconium oxide in the friction material composition is 20% by mass or more based on 100% by mass of the friction material composition. , preferably 30% by mass or less.
（単斜晶酸化ジルコニウムの粒径）
前述の（ｉ）および（ｉｉ）の効果の発現の観点で、単斜晶酸化ジルコニウムの粒径は特に限定されない。このため、摩擦材に添加される無機充填材として通常採用される粒径の単斜晶酸化ジルコニウムを適宜選択することができる。摩擦材組成物の製造時の取扱い性の観点からは、単斜晶酸化ジルコニウムの平均粒径が１μｍ以上であることが好ましく、３μｍ以上であることがより好ましく、５μｍ以上であることがより好ましく、７μｍ以上であることがより好ましく、１０μｍ以上であることがさらに好ましい。また、摩擦材組成物の製造時に偏りなく均一に混合することが可能となる、および耐摩耗性の低下に対する影響が少ない等の理由から、単斜晶酸化ジルコニウムの平均粒径が２０μｍ以下であることが好ましく、１８μｍ以下であることがより好ましく、１６μｍ以下であることがさらに好ましい。 (Particle size of monoclinic zirconium oxide)
From the viewpoint of achieving the effects (i) and (ii) described above, the particle size of monoclinic zirconium oxide is not particularly limited. Therefore, monoclinic zirconium oxide having a particle size that is normally employed as an inorganic filler added to friction materials can be appropriately selected. From the viewpoint of handleability during production of the friction material composition, the average particle size of monoclinic zirconium oxide is preferably 1 μm or more, more preferably 3 μm or more, and even more preferably 5 μm or more. , more preferably 7 μm or more, and even more preferably 10 μm or more. In addition, the average particle size of the monoclinic zirconium oxide is 20 μm or less because it enables uniform mixing without bias during production of the friction material composition and has little effect on deterioration of wear resistance. It is preferably 18 μm or less, more preferably 16 μm or less.
前述の（ｉ）および（ｉｉ）の効果の発現の観点で、単斜晶酸化ジルコニウムの粒径は特に限定されない。このため、摩擦材に添加される無機充填材として通常採用される粒径の単斜晶酸化ジルコニウムを適宜選択することができる。摩擦材組成物の製造時の取扱い性の観点からは、単斜晶酸化ジルコニウムの平均粒径が１μｍ以上であることが好ましく、３μｍ以上であることがより好ましく、５μｍ以上であることがより好ましく、７μｍ以上であることがより好ましく、１０μｍ以上であることがさらに好ましい。また、摩擦材組成物の製造時に偏りなく均一に混合することが可能となる、および耐摩耗性の低下に対する影響が少ない等の理由から、単斜晶酸化ジルコニウムの平均粒径が２０μｍ以下であることが好ましく、１８μｍ以下であることがより好ましく、１６μｍ以下であることがさらに好ましい。 (Particle size of monoclinic zirconium oxide)
From the viewpoint of achieving the effects (i) and (ii) described above, the particle size of monoclinic zirconium oxide is not particularly limited. Therefore, monoclinic zirconium oxide having a particle size that is normally employed as an inorganic filler added to friction materials can be appropriately selected. From the viewpoint of handleability during production of the friction material composition, the average particle size of monoclinic zirconium oxide is preferably 1 μm or more, more preferably 3 μm or more, and even more preferably 5 μm or more. , more preferably 7 μm or more, and even more preferably 10 μm or more. In addition, the average particle size of the monoclinic zirconium oxide is 20 μm or less because it enables uniform mixing without bias during production of the friction material composition and has little effect on deterioration of wear resistance. It is preferably 18 μm or less, more preferably 16 μm or less.
単斜晶酸化ジルコニウムの平均粒径は、ＪＩＳ Ｚ ８８２５「粒子径解析－レーザ解析・散乱法」により得られる体積基準の中位径（メジアン径）とする。摩擦材形成後に単斜晶酸化ジルコニウムの粒子径を確認する場合は、摩擦材の断面の電子顕微鏡画像から単斜晶酸化ジルコニウムに該当する粒子の平均粒径をＪＩＳ Ｚ ８８２７－１「粒子径解析－画像解析法－第１部：静的画像解析法」により体積基準の粒度分布を測定し、中位径を求めればよい。
The average particle size of monoclinic zirconium oxide is the volume-based median diameter obtained by JIS Z 8825 "Particle size analysis - laser analysis/scattering method". When confirming the particle size of monoclinic zirconium oxide after forming the friction material, calculate the average particle size of particles corresponding to monoclinic zirconium oxide from an electron microscope image of the cross section of the friction material using JIS Z 8827-1 "Particle size analysis. - Image analysis method - Part 1: Static image analysis method'' to measure the volume-based particle size distribution and determine the median diameter.
（非加硫エラストマー）
本発明の一態様に係る摩擦材組成物は、有機充填材として、非加硫エラストマーを含んでいることが好ましい。本明細書において、「非加硫エラストマー」は、加硫されていないエラストマーを指す。非加硫エラストマーは、市街地走行時のような常用の温度域（例えば、１００～２００℃）で軟化する（可塑性を有する）ものであることが好ましい。 (Non-vulcanized elastomer)
The friction material composition according to one aspect of the present invention preferably contains a non-vulcanized elastomer as the organic filler. As used herein, "unvulcanized elastomer" refers to an elastomer that has not been vulcanized. The non-vulcanized elastomer is preferably one that softens (has plasticity) in a common temperature range (for example, 100 to 200° C.) such as when driving around town.
本発明の一態様に係る摩擦材組成物は、有機充填材として、非加硫エラストマーを含んでいることが好ましい。本明細書において、「非加硫エラストマー」は、加硫されていないエラストマーを指す。非加硫エラストマーは、市街地走行時のような常用の温度域（例えば、１００～２００℃）で軟化する（可塑性を有する）ものであることが好ましい。 (Non-vulcanized elastomer)
The friction material composition according to one aspect of the present invention preferably contains a non-vulcanized elastomer as the organic filler. As used herein, "unvulcanized elastomer" refers to an elastomer that has not been vulcanized. The non-vulcanized elastomer is preferably one that softens (has plasticity) in a common temperature range (for example, 100 to 200° C.) such as when driving around town.
（非加硫エラストマーの作用および効果）
非加硫エラストマーは、常用の温度域で軟化するため、非加硫エラストマーを含む摩擦材は、常用の温度域での耐摩耗性がより向上する。また、常用の温度域での制動時（低温制動時）に、単斜晶酸化ジルコニウムおよび水酸化マグネシウムが、軟化した非加硫エラストマーに付着する。このため、単斜晶酸化ジルコニウムおよび水酸化マグネシウムが摩擦面に保持されることで摩擦面から失われ難くなる。その結果、非加硫エラストマーを含んでいない摩擦材と比較して、耐摩耗性および防錆性がより向上する。 (Functions and effects of non-vulcanized elastomer)
Since the non-vulcanized elastomer softens in the normal temperature range, a friction material containing the non-vulcanized elastomer has improved wear resistance in the normal temperature range. Furthermore, during braking in a normal temperature range (low-temperature braking), monoclinic zirconium oxide and magnesium hydroxide adhere to the softened non-vulcanized elastomer. Therefore, monoclinic zirconium oxide and magnesium hydroxide are retained on the friction surface, making it difficult for them to be lost from the friction surface. As a result, wear resistance and rust prevention properties are further improved compared to friction materials that do not contain a non-vulcanized elastomer.
非加硫エラストマーは、常用の温度域で軟化するため、非加硫エラストマーを含む摩擦材は、常用の温度域での耐摩耗性がより向上する。また、常用の温度域での制動時（低温制動時）に、単斜晶酸化ジルコニウムおよび水酸化マグネシウムが、軟化した非加硫エラストマーに付着する。このため、単斜晶酸化ジルコニウムおよび水酸化マグネシウムが摩擦面に保持されることで摩擦面から失われ難くなる。その結果、非加硫エラストマーを含んでいない摩擦材と比較して、耐摩耗性および防錆性がより向上する。 (Functions and effects of non-vulcanized elastomer)
Since the non-vulcanized elastomer softens in the normal temperature range, a friction material containing the non-vulcanized elastomer has improved wear resistance in the normal temperature range. Furthermore, during braking in a normal temperature range (low-temperature braking), monoclinic zirconium oxide and magnesium hydroxide adhere to the softened non-vulcanized elastomer. Therefore, monoclinic zirconium oxide and magnesium hydroxide are retained on the friction surface, making it difficult for them to be lost from the friction surface. As a result, wear resistance and rust prevention properties are further improved compared to friction materials that do not contain a non-vulcanized elastomer.
（非加硫エラストマーの種類）
前述の効果の発現の観点で、非加硫エラストマーの種類は特に限定されず、あらゆる非加硫エラストマーを好ましく使用することができる。非加硫エラストマーとしては、例えば、天然ゴム（ＮＲ）、イソプレンゴム（ＩＲ）、ブタジエンゴム（ＢＲ）、スチレンブタジエンゴム（ＳＢＲ）、クロロプレンゴム（ＣＲ）、アクリロニトリルブタジエンゴム（ＮＢＲ）等の非加硫のジエン系ゴム；ブチルゴム（ＩＩＲ）、エチレンプロピレンゴム（ＥＰＭ）、ウレタンゴム（Ｕ）、シリコーンゴム（Ｑ）、クロロスルホン化ポリエチレン（ＣＳＭ）、塩素化ポリエチレン（ＣＭ）、アクリルゴム（ＡＣＭ）、エピクロヒドリンゴム（ＣＯ）、フッ素ゴム（ＦＫＭ）等の非加硫の非ジエン系ゴム；１，２ポリブタジエン、エチレン－オクテンコポリマー、エチレン－αオレフィンコポリマー等の熱可塑性エラストマー；等を挙げることができる。非加硫エラストマーは、１種類を単独でまたは複数種類を組み合わせて使用することができる。 (Type of non-vulcanized elastomer)
From the viewpoint of achieving the above-mentioned effects, the type of non-vulcanized elastomer is not particularly limited, and any non-vulcanized elastomer can be preferably used. Examples of non-vulcanized elastomers include natural rubber (NR), isoprene rubber (IR), butadiene rubber (BR), styrene-butadiene rubber (SBR), chloroprene rubber (CR), and acrylonitrile-butadiene rubber (NBR). Sulfuric diene rubber; butyl rubber (IIR), ethylene propylene rubber (EPM), urethane rubber (U), silicone rubber (Q), chlorosulfonated polyethylene (CSM), chlorinated polyethylene (CM), acrylic rubber (ACM) , non-vulcanized non-diene rubbers such as epichlorohydrin rubber (CO) and fluororubber (FKM); thermoplastic elastomers such as 1,2 polybutadiene, ethylene-octene copolymers, and ethylene-α-olefin copolymers; Can be done. The non-vulcanized elastomer can be used singly or in combination.
前述の効果の発現の観点で、非加硫エラストマーの種類は特に限定されず、あらゆる非加硫エラストマーを好ましく使用することができる。非加硫エラストマーとしては、例えば、天然ゴム（ＮＲ）、イソプレンゴム（ＩＲ）、ブタジエンゴム（ＢＲ）、スチレンブタジエンゴム（ＳＢＲ）、クロロプレンゴム（ＣＲ）、アクリロニトリルブタジエンゴム（ＮＢＲ）等の非加硫のジエン系ゴム；ブチルゴム（ＩＩＲ）、エチレンプロピレンゴム（ＥＰＭ）、ウレタンゴム（Ｕ）、シリコーンゴム（Ｑ）、クロロスルホン化ポリエチレン（ＣＳＭ）、塩素化ポリエチレン（ＣＭ）、アクリルゴム（ＡＣＭ）、エピクロヒドリンゴム（ＣＯ）、フッ素ゴム（ＦＫＭ）等の非加硫の非ジエン系ゴム；１，２ポリブタジエン、エチレン－オクテンコポリマー、エチレン－αオレフィンコポリマー等の熱可塑性エラストマー；等を挙げることができる。非加硫エラストマーは、１種類を単独でまたは複数種類を組み合わせて使用することができる。 (Type of non-vulcanized elastomer)
From the viewpoint of achieving the above-mentioned effects, the type of non-vulcanized elastomer is not particularly limited, and any non-vulcanized elastomer can be preferably used. Examples of non-vulcanized elastomers include natural rubber (NR), isoprene rubber (IR), butadiene rubber (BR), styrene-butadiene rubber (SBR), chloroprene rubber (CR), and acrylonitrile-butadiene rubber (NBR). Sulfuric diene rubber; butyl rubber (IIR), ethylene propylene rubber (EPM), urethane rubber (U), silicone rubber (Q), chlorosulfonated polyethylene (CSM), chlorinated polyethylene (CM), acrylic rubber (ACM) , non-vulcanized non-diene rubbers such as epichlorohydrin rubber (CO) and fluororubber (FKM); thermoplastic elastomers such as 1,2 polybutadiene, ethylene-octene copolymers, and ethylene-α-olefin copolymers; Can be done. The non-vulcanized elastomer can be used singly or in combination.
また、前述の効果の発現の観点で、非加硫エラストマーの形状は特に限定されず、任意の形状を有するものを適宜使用することができる。但し、摩擦材組成物の製造時の混合の容易性の観点から、粒状であることが好ましい。
Furthermore, from the viewpoint of achieving the above-mentioned effects, the shape of the non-vulcanized elastomer is not particularly limited, and any shape can be used as appropriate. However, from the viewpoint of ease of mixing during production of the friction material composition, it is preferably granular.
（非加硫エラストマーの含有量）
摩擦材組成物中の非加硫エラストマーの含有量は特に限定されず、非加硫エラストマーを含有することによる所期の効果が十分に発現される範囲で適宜決定することができる。常用の温度域での摩擦材の耐摩耗性および防錆性をより向上させる観点から、摩擦材組成物中の非加硫エラストマーの含有量は、摩擦材組成物１００質量％に対して０．５質量％以上であることが好ましく、１質量％以上であることがより好ましい。また、摩擦材組成物中に含まれている他の成分との配合バランスの観点から、摩擦材組成物中の非加硫エラストマーの含有量は、摩擦材組成物１００質量％に対して１０質量％以下であることが好ましく、３質量％以下であることがより好ましい。 (Content of non-vulcanized elastomer)
The content of the non-vulcanized elastomer in the friction material composition is not particularly limited, and can be determined as appropriate within a range in which the intended effect of containing the non-vulcanized elastomer is sufficiently exhibited. From the perspective of further improving the wear resistance and rust prevention properties of the friction material in the commonly used temperature range, the content of the non-vulcanized elastomer in the friction material composition is 0.0% based on 100% by mass of the friction material composition. It is preferably 5% by mass or more, more preferably 1% by mass or more. In addition, from the viewpoint of blending balance with other components contained in the friction material composition, the content of non-vulcanized elastomer in the friction material composition is 10% by mass based on 100% by mass of the friction material composition. % or less, more preferably 3% by mass or less.
摩擦材組成物中の非加硫エラストマーの含有量は特に限定されず、非加硫エラストマーを含有することによる所期の効果が十分に発現される範囲で適宜決定することができる。常用の温度域での摩擦材の耐摩耗性および防錆性をより向上させる観点から、摩擦材組成物中の非加硫エラストマーの含有量は、摩擦材組成物１００質量％に対して０．５質量％以上であることが好ましく、１質量％以上であることがより好ましい。また、摩擦材組成物中に含まれている他の成分との配合バランスの観点から、摩擦材組成物中の非加硫エラストマーの含有量は、摩擦材組成物１００質量％に対して１０質量％以下であることが好ましく、３質量％以下であることがより好ましい。 (Content of non-vulcanized elastomer)
The content of the non-vulcanized elastomer in the friction material composition is not particularly limited, and can be determined as appropriate within a range in which the intended effect of containing the non-vulcanized elastomer is sufficiently exhibited. From the perspective of further improving the wear resistance and rust prevention properties of the friction material in the commonly used temperature range, the content of the non-vulcanized elastomer in the friction material composition is 0.0% based on 100% by mass of the friction material composition. It is preferably 5% by mass or more, more preferably 1% by mass or more. In addition, from the viewpoint of blending balance with other components contained in the friction material composition, the content of non-vulcanized elastomer in the friction material composition is 10% by mass based on 100% by mass of the friction material composition. % or less, more preferably 3% by mass or less.
（その他の成分）
本態様の摩擦材組成物は、上述した成分の他に、繊維基材、結合材、非加硫エラストマーとは異なる別の有機充填材、並びに水酸化マグネシウムおよび単斜晶酸化ジルコニウムとは異なる別の無機充填材を摩擦材原料として含有してもよい。 (Other ingredients)
In addition to the above-mentioned components, the friction material composition of this embodiment includes a fiber base material, a binder, an organic filler different from the non-vulcanized elastomer, and an organic filler different from magnesium hydroxide and monoclinic zirconium oxide. The friction material may contain an inorganic filler as a raw material for the friction material.
本態様の摩擦材組成物は、上述した成分の他に、繊維基材、結合材、非加硫エラストマーとは異なる別の有機充填材、並びに水酸化マグネシウムおよび単斜晶酸化ジルコニウムとは異なる別の無機充填材を摩擦材原料として含有してもよい。 (Other ingredients)
In addition to the above-mentioned components, the friction material composition of this embodiment includes a fiber base material, a binder, an organic filler different from the non-vulcanized elastomer, and an organic filler different from magnesium hydroxide and monoclinic zirconium oxide. The friction material may contain an inorganic filler as a raw material for the friction material.
（繊維基材）
繊維基材としては、例えば、有機繊維、無機繊維、金属繊維等を挙げることができる。これらの繊維は、天然繊維であってもよく、人工的に合成した合成繊維であってもよい。有機繊維としては、例えば、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、炭素繊維等を挙げることができる。無機繊維としては、ロックウール、ガラス繊維等を挙げることができる。金属繊維としては、スチール、ステンレス、アルミニウム、亜鉛、スズ等の単独金属からなる繊維、並びに、それぞれの合金金属からなる繊維を挙げることができる。繊維基材は、１種類を単独でまたは複数種類を組み合わせて使用することができる。摩擦材組成物中の繊維基材の含有量は特に限定されず、当該技術分野で通常採用される含有量とすることができる。 (fiber base material)
Examples of the fiber base material include organic fibers, inorganic fibers, and metal fibers. These fibers may be natural fibers or artificially synthesized synthetic fibers. Examples of organic fibers include aromatic polyamide fibers (aramid fibers), acrylic fibers, cellulose fibers, and carbon fibers. Examples of the inorganic fiber include rock wool and glass fiber. Examples of metal fibers include fibers made of single metals such as steel, stainless steel, aluminum, zinc, and tin, as well as fibers made of alloy metals of the respective metals. The fiber base material can be used singly or in combination. The content of the fiber base material in the friction material composition is not particularly limited, and can be a content commonly employed in the technical field.
繊維基材としては、例えば、有機繊維、無機繊維、金属繊維等を挙げることができる。これらの繊維は、天然繊維であってもよく、人工的に合成した合成繊維であってもよい。有機繊維としては、例えば、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、炭素繊維等を挙げることができる。無機繊維としては、ロックウール、ガラス繊維等を挙げることができる。金属繊維としては、スチール、ステンレス、アルミニウム、亜鉛、スズ等の単独金属からなる繊維、並びに、それぞれの合金金属からなる繊維を挙げることができる。繊維基材は、１種類を単独でまたは複数種類を組み合わせて使用することができる。摩擦材組成物中の繊維基材の含有量は特に限定されず、当該技術分野で通常採用される含有量とすることができる。 (fiber base material)
Examples of the fiber base material include organic fibers, inorganic fibers, and metal fibers. These fibers may be natural fibers or artificially synthesized synthetic fibers. Examples of organic fibers include aromatic polyamide fibers (aramid fibers), acrylic fibers, cellulose fibers, and carbon fibers. Examples of the inorganic fiber include rock wool and glass fiber. Examples of metal fibers include fibers made of single metals such as steel, stainless steel, aluminum, zinc, and tin, as well as fibers made of alloy metals of the respective metals. The fiber base material can be used singly or in combination. The content of the fiber base material in the friction material composition is not particularly limited, and can be a content commonly employed in the technical field.
（結合材）
結合材は、摩擦材組成物中の摩擦材原料を結合させる機能を有している。結合材としては、前記性能を発揮できるものであれば特に限定されず、当該技術分野で公知の結合材を好ましく使用することができる。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、イミド樹脂等の樹脂を挙げることができる。結合材は、１種類を単独でまたは複数種類を組み合わせて使用することができる。摩擦材組成物中の結合材の含有量は特に限定されず、当該技術分野で通常採用される含有量とすることができる。また、結合剤はシリコーンゴム、アクリルゴム、カシューオイル等の変性成分を含んでいてもよい。 (Binding material)
The binding material has a function of binding friction material raw materials in the friction material composition. The binding material is not particularly limited as long as it can exhibit the above performance, and binding materials known in the technical field can be preferably used. Specific examples of the binder include resins such as phenol resin, epoxy resin, melamine resin, and imide resin. The binder can be used singly or in combination. The content of the binder in the friction material composition is not particularly limited, and can be a content commonly employed in the technical field. Further, the binder may contain modifying components such as silicone rubber, acrylic rubber, and cashew oil.
結合材は、摩擦材組成物中の摩擦材原料を結合させる機能を有している。結合材としては、前記性能を発揮できるものであれば特に限定されず、当該技術分野で公知の結合材を好ましく使用することができる。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、イミド樹脂等の樹脂を挙げることができる。結合材は、１種類を単独でまたは複数種類を組み合わせて使用することができる。摩擦材組成物中の結合材の含有量は特に限定されず、当該技術分野で通常採用される含有量とすることができる。また、結合剤はシリコーンゴム、アクリルゴム、カシューオイル等の変性成分を含んでいてもよい。 (Binding material)
The binding material has a function of binding friction material raw materials in the friction material composition. The binding material is not particularly limited as long as it can exhibit the above performance, and binding materials known in the technical field can be preferably used. Specific examples of the binder include resins such as phenol resin, epoxy resin, melamine resin, and imide resin. The binder can be used singly or in combination. The content of the binder in the friction material composition is not particularly limited, and can be a content commonly employed in the technical field. Further, the binder may contain modifying components such as silicone rubber, acrylic rubber, and cashew oil.
（非加硫エラストマーとは異なる別の有機充填材）
本態様の摩擦材組成物は、本発明の効果を損なわない範囲で、非加硫エラストマーとは異なる別の有機充填材を含んでいてもよい。有機充填材は、耐摩耗性等を向上させるための摩擦調整材としての機能を有している。非加硫エラストマーとは異なる別の有機充填材としては、前記性能を発揮できるものであれば特に限定されず、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。非加硫エラストマーとは異なる別の有機充填材の具体例としては、ゴム粉、タイヤ粉、カシューダスト、フッ素樹脂、メラミンシアヌレート、ポリエチレン樹脂等を挙げることができる。有機充填材は、１種類を単独でまたは複数種類を組み合わせて使用することができる。また、有機充填材は、リン酸やフッ素樹脂によって表面を被覆していてもよい。非加硫エラストマーとは異なる別の有機充填材の含有量は特に限定されず、非加硫エラストマーとあわせた有機充填材の総含有量が当該技術分野で採用される有機充填材の含有量の範囲となるように適宜調整すればよい。本態様の摩擦材組成物は、非加硫エラストマーの効果を損なわない程度の少量であれば、加硫エラストマー（例えば、加硫ゴムなど）を含むことを妨げない。 (Another organic filler different from non-vulcanized elastomer)
The friction material composition of this embodiment may contain another organic filler different from the non-vulcanized elastomer to the extent that the effects of the present invention are not impaired. The organic filler has a function as a friction modifier to improve wear resistance and the like. The organic filler different from the non-vulcanized elastomer is not particularly limited as long as it can exhibit the above performance, and organic fillers known in the technical field can be preferably used. Specific examples of organic fillers different from non-vulcanized elastomers include rubber powder, tire powder, cashew dust, fluororesin, melamine cyanurate, polyethylene resin, and the like. One kind of organic filler can be used alone or a plurality of kinds can be used in combination. Further, the surface of the organic filler may be coated with phosphoric acid or fluororesin. The content of another organic filler different from the non-vulcanized elastomer is not particularly limited, and the total content of the organic filler including the non-vulcanized elastomer is the same as the content of organic fillers adopted in the technical field. It may be adjusted as appropriate so that it falls within the range. The friction material composition of this embodiment may contain a vulcanized elastomer (for example, vulcanized rubber) as long as the amount is small enough not to impair the effects of the non-vulcanized elastomer.
本態様の摩擦材組成物は、本発明の効果を損なわない範囲で、非加硫エラストマーとは異なる別の有機充填材を含んでいてもよい。有機充填材は、耐摩耗性等を向上させるための摩擦調整材としての機能を有している。非加硫エラストマーとは異なる別の有機充填材としては、前記性能を発揮できるものであれば特に限定されず、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。非加硫エラストマーとは異なる別の有機充填材の具体例としては、ゴム粉、タイヤ粉、カシューダスト、フッ素樹脂、メラミンシアヌレート、ポリエチレン樹脂等を挙げることができる。有機充填材は、１種類を単独でまたは複数種類を組み合わせて使用することができる。また、有機充填材は、リン酸やフッ素樹脂によって表面を被覆していてもよい。非加硫エラストマーとは異なる別の有機充填材の含有量は特に限定されず、非加硫エラストマーとあわせた有機充填材の総含有量が当該技術分野で採用される有機充填材の含有量の範囲となるように適宜調整すればよい。本態様の摩擦材組成物は、非加硫エラストマーの効果を損なわない程度の少量であれば、加硫エラストマー（例えば、加硫ゴムなど）を含むことを妨げない。 (Another organic filler different from non-vulcanized elastomer)
The friction material composition of this embodiment may contain another organic filler different from the non-vulcanized elastomer to the extent that the effects of the present invention are not impaired. The organic filler has a function as a friction modifier to improve wear resistance and the like. The organic filler different from the non-vulcanized elastomer is not particularly limited as long as it can exhibit the above performance, and organic fillers known in the technical field can be preferably used. Specific examples of organic fillers different from non-vulcanized elastomers include rubber powder, tire powder, cashew dust, fluororesin, melamine cyanurate, polyethylene resin, and the like. One kind of organic filler can be used alone or a plurality of kinds can be used in combination. Further, the surface of the organic filler may be coated with phosphoric acid or fluororesin. The content of another organic filler different from the non-vulcanized elastomer is not particularly limited, and the total content of the organic filler including the non-vulcanized elastomer is the same as the content of organic fillers adopted in the technical field. It may be adjusted as appropriate so that it falls within the range. The friction material composition of this embodiment may contain a vulcanized elastomer (for example, vulcanized rubber) as long as the amount is small enough not to impair the effects of the non-vulcanized elastomer.
（単斜晶酸化ジルコニウムおよび水酸化マグネシウムとは異なる別の無機充填材）
本態様の摩擦材組成物は、本発明の効果を損なわない範囲で、単斜晶酸化ジルコニウムおよび水酸化マグネシウムとは異なる別の無機充填材を含んでいてもよい。単斜晶酸化ジルコニウムおよび水酸化マグネシウムとは異なる別の無機充填材としては、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、例えば、硫酸バリウム、マイカ、酸化鉄（酸化第一鉄、酸化第二鉄等）、チタン酸塩、水酸化カルシウム等を挙げることができる。チタン酸塩としては、例えば、チタン酸アルカリ金属塩、チタン酸アルカリ金属・第二族塩等を挙げることができ、具体例として、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。これらの無機充填材は、１種類を単独でまたは複数種類を組み合わせて使用することができる。摩擦材組成物中の単斜晶酸化ジルコニウムおよび水酸化マグネシウムとは異なる別の無機充填材の含有量は特に限定されず、単斜晶酸化ジルコニウムおよび水酸化マグネシウムとあわせた無機充填材の総含有量が当該技術分野で採用される無機充填材の含有量の範囲となるように適宜調整すればよい。 (Another inorganic filler different from monoclinic zirconium oxide and magnesium hydroxide)
The friction material composition of this embodiment may contain an inorganic filler different from monoclinic zirconium oxide and magnesium hydroxide as long as the effects of the present invention are not impaired. As another inorganic filler different from monoclinic zirconium oxide and magnesium hydroxide, inorganics known in the art can preferably be used, such as barium sulfate, mica, iron oxide (ferrous oxide, (ferric oxide, etc.), titanates, calcium hydroxide, etc. Examples of titanates include alkali metal titanates, alkali metal titanate second group salts, and specific examples include potassium titanate, sodium titanate, lithium titanate, and lithium potassium titanate. , magnesium potassium titanate, and the like. These inorganic fillers can be used singly or in combination. The content of an inorganic filler different from monoclinic zirconium oxide and magnesium hydroxide in the friction material composition is not particularly limited, and the total content of inorganic fillers together with monoclinic zirconium oxide and magnesium hydroxide The amount may be adjusted as appropriate so that it falls within the range of inorganic filler content adopted in the technical field.
本態様の摩擦材組成物は、本発明の効果を損なわない範囲で、単斜晶酸化ジルコニウムおよび水酸化マグネシウムとは異なる別の無機充填材を含んでいてもよい。単斜晶酸化ジルコニウムおよび水酸化マグネシウムとは異なる別の無機充填材としては、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、例えば、硫酸バリウム、マイカ、酸化鉄（酸化第一鉄、酸化第二鉄等）、チタン酸塩、水酸化カルシウム等を挙げることができる。チタン酸塩としては、例えば、チタン酸アルカリ金属塩、チタン酸アルカリ金属・第二族塩等を挙げることができ、具体例として、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。これらの無機充填材は、１種類を単独でまたは複数種類を組み合わせて使用することができる。摩擦材組成物中の単斜晶酸化ジルコニウムおよび水酸化マグネシウムとは異なる別の無機充填材の含有量は特に限定されず、単斜晶酸化ジルコニウムおよび水酸化マグネシウムとあわせた無機充填材の総含有量が当該技術分野で採用される無機充填材の含有量の範囲となるように適宜調整すればよい。 (Another inorganic filler different from monoclinic zirconium oxide and magnesium hydroxide)
The friction material composition of this embodiment may contain an inorganic filler different from monoclinic zirconium oxide and magnesium hydroxide as long as the effects of the present invention are not impaired. As another inorganic filler different from monoclinic zirconium oxide and magnesium hydroxide, inorganics known in the art can preferably be used, such as barium sulfate, mica, iron oxide (ferrous oxide, (ferric oxide, etc.), titanates, calcium hydroxide, etc. Examples of titanates include alkali metal titanates, alkali metal titanate second group salts, and specific examples include potassium titanate, sodium titanate, lithium titanate, and lithium potassium titanate. , magnesium potassium titanate, and the like. These inorganic fillers can be used singly or in combination. The content of an inorganic filler different from monoclinic zirconium oxide and magnesium hydroxide in the friction material composition is not particularly limited, and the total content of inorganic fillers together with monoclinic zirconium oxide and magnesium hydroxide The amount may be adjusted as appropriate so that it falls within the range of inorganic filler content adopted in the technical field.
単斜晶酸化ジルコニウムおよび水酸化マグネシウムとは異なる別の無機充填材として、チタン酸塩を含有することにより、６５０℃以上の温度域での高速制動時の摩擦面において形成される被膜がより強固になり、摩擦材の耐熱性（効きおよび耐摩耗性）がより向上するため好ましい。この場合のチタン酸塩の含有量の上限は特に限定されず、単斜晶酸化ジルコニウムおよび水酸化マグネシウムとあわせた無機充填材の総含有量が当該技術分野で採用される無機充填材の含有量となるように適宜調整すればよい。チタン酸塩の含有量が多い程、前述した摩擦材の耐熱性がより向上するため好ましい。
By containing titanate as an inorganic filler different from monoclinic zirconium oxide and magnesium hydroxide, the film formed on the friction surface during high-speed braking in the temperature range of 650°C or higher becomes stronger. This is preferable because the heat resistance (effectiveness and wear resistance) of the friction material is further improved. In this case, the upper limit of the titanate content is not particularly limited, and the total content of the inorganic filler including monoclinic zirconium oxide and magnesium hydroxide is the content of the inorganic filler adopted in the technical field. It may be adjusted as appropriate so that. The higher the titanate content, the more the heat resistance of the friction material described above is improved, so it is preferable.
また、単斜晶酸化ジルコニウムおよび水酸化マグネシウムとは異なる別の無機充填材の粒径は特に限定されず、当該技術分野で通常採用される平均粒径を有する無機物を好ましく使用することができる。
Furthermore, the particle size of the inorganic filler different from monoclinic zirconium oxide and magnesium hydroxide is not particularly limited, and inorganic substances having an average particle size commonly employed in the technical field can be preferably used.
（潤滑剤）
本態様の摩擦材組成物は、本発明の効果を損なわない範囲で、潤滑剤をさらに含んでいてもよい。潤滑剤としては特に限定されず、当該技術分野で公知の潤滑剤を好ましく使用することができる。潤滑剤の具体例としては、コークス、黒鉛、カーボンブラック、グラファイト、金属硫化物等を挙げることができる。金属硫化物としては、例えば、硫化スズ、三硫化アンチモン、二硫化モリブテン、硫化ビスマス、硫化鉄、硫化亜鉛、硫化タングステン等を挙げることができる。これらの潤滑剤は、１種類を単独でまたは複数種類を組み合わせて使用することができる。潤滑剤の含有量は特に限定されず、当該技術分野で通常採用される含有量とすることができる。 (lubricant)
The friction material composition of this embodiment may further contain a lubricant to the extent that the effects of the present invention are not impaired. The lubricant is not particularly limited, and any lubricant known in the technical field can be preferably used. Specific examples of the lubricant include coke, graphite, carbon black, graphite, metal sulfide, and the like. Examples of metal sulfides include tin sulfide, antimony trisulfide, molybdenum disulfide, bismuth sulfide, iron sulfide, zinc sulfide, and tungsten sulfide. These lubricants can be used alone or in combination. The content of the lubricant is not particularly limited, and can be a content commonly employed in the technical field.
本態様の摩擦材組成物は、本発明の効果を損なわない範囲で、潤滑剤をさらに含んでいてもよい。潤滑剤としては特に限定されず、当該技術分野で公知の潤滑剤を好ましく使用することができる。潤滑剤の具体例としては、コークス、黒鉛、カーボンブラック、グラファイト、金属硫化物等を挙げることができる。金属硫化物としては、例えば、硫化スズ、三硫化アンチモン、二硫化モリブテン、硫化ビスマス、硫化鉄、硫化亜鉛、硫化タングステン等を挙げることができる。これらの潤滑剤は、１種類を単独でまたは複数種類を組み合わせて使用することができる。潤滑剤の含有量は特に限定されず、当該技術分野で通常採用される含有量とすることができる。 (lubricant)
The friction material composition of this embodiment may further contain a lubricant to the extent that the effects of the present invention are not impaired. The lubricant is not particularly limited, and any lubricant known in the technical field can be preferably used. Specific examples of the lubricant include coke, graphite, carbon black, graphite, metal sulfide, and the like. Examples of metal sulfides include tin sulfide, antimony trisulfide, molybdenum disulfide, bismuth sulfide, iron sulfide, zinc sulfide, and tungsten sulfide. These lubricants can be used alone or in combination. The content of the lubricant is not particularly limited, and can be a content commonly employed in the technical field.
（摩擦材組成物の製造方法）
本態様の摩擦材組成物は、上述した摩擦材原料を配合し、それらを混合する混合工程を含む製造方法によって製造することができる。摩擦材原料を均一に混合する観点から、混合工程は、粉体状の摩擦材原料を混合する工程であることが好ましい。混合工程における混合方法および混合条件は、摩擦材原料を均一に混合することができる限り特に限定されず、当該技術分野で公知の方法を採用することができる。例えば、フェンシェルミキサ、レーディゲミキサ等の公知の混合機を使用して、摩擦材原料を常温で１０分間程度混合すればよい。混合工程では、混合中の摩擦材原料が昇温しないように、公知の冷却方法によって摩擦材原料の混合物を冷却しながら混合してもよい。 (Method for manufacturing friction material composition)
The friction material composition of this embodiment can be manufactured by a manufacturing method including a mixing step of blending the above-mentioned friction material raw materials and mixing them. From the viewpoint of uniformly mixing the friction material raw materials, the mixing step is preferably a step of mixing powdered friction material raw materials. The mixing method and mixing conditions in the mixing step are not particularly limited as long as the friction material raw materials can be mixed uniformly, and methods known in the technical field can be adopted. For example, the friction material raw materials may be mixed at room temperature for about 10 minutes using a known mixer such as a Fenschel mixer or a Loedige mixer. In the mixing step, the mixture of friction material raw materials may be cooled and mixed using a known cooling method so as not to increase the temperature of the friction material raw materials being mixed.
本態様の摩擦材組成物は、上述した摩擦材原料を配合し、それらを混合する混合工程を含む製造方法によって製造することができる。摩擦材原料を均一に混合する観点から、混合工程は、粉体状の摩擦材原料を混合する工程であることが好ましい。混合工程における混合方法および混合条件は、摩擦材原料を均一に混合することができる限り特に限定されず、当該技術分野で公知の方法を採用することができる。例えば、フェンシェルミキサ、レーディゲミキサ等の公知の混合機を使用して、摩擦材原料を常温で１０分間程度混合すればよい。混合工程では、混合中の摩擦材原料が昇温しないように、公知の冷却方法によって摩擦材原料の混合物を冷却しながら混合してもよい。 (Method for manufacturing friction material composition)
The friction material composition of this embodiment can be manufactured by a manufacturing method including a mixing step of blending the above-mentioned friction material raw materials and mixing them. From the viewpoint of uniformly mixing the friction material raw materials, the mixing step is preferably a step of mixing powdered friction material raw materials. The mixing method and mixing conditions in the mixing step are not particularly limited as long as the friction material raw materials can be mixed uniformly, and methods known in the technical field can be adopted. For example, the friction material raw materials may be mixed at room temperature for about 10 minutes using a known mixer such as a Fenschel mixer or a Loedige mixer. In the mixing step, the mixture of friction material raw materials may be cooled and mixed using a known cooling method so as not to increase the temperature of the friction material raw materials being mixed.
＜２．摩擦材＞
本発明の一態様に係る摩擦材は、本発明の一態様に係る摩擦材組成物を成形してなる。本態様の摩擦材の効果、用途等は本発明の摩擦材組成物の一態様について説明したとおりであるのでここでは繰り返さない。 <2. Friction material>
A friction material according to one embodiment of the present invention is formed by molding a friction material composition according to one embodiment of the present invention. The effects, uses, etc. of the friction material of this embodiment are as described for one embodiment of the friction material composition of the present invention, so they will not be repeated here.
本発明の一態様に係る摩擦材は、本発明の一態様に係る摩擦材組成物を成形してなる。本態様の摩擦材の効果、用途等は本発明の摩擦材組成物の一態様について説明したとおりであるのでここでは繰り返さない。 <2. Friction material>
A friction material according to one embodiment of the present invention is formed by molding a friction material composition according to one embodiment of the present invention. The effects, uses, etc. of the friction material of this embodiment are as described for one embodiment of the friction material composition of the present invention, so they will not be repeated here.
（摩擦材の製造方法）
本態様の摩擦材は、本発明の一態様に係る摩擦材組成物を成形する成形工程を含む製造方法によって製造することができる。成形工程における成形方法および成形条件は、本発明の摩擦材組成物の一態様を所定の形状に成形することができる限り特に限定されず、当該技術分野で公知の方法を採用することができる。例えば、本発明の摩擦材組成物の一態様をプレス等で押し固めることにより成形することができる。プレスによる成形方法としては、本発明の摩擦材組成物の一態様を加熱して押し固めて成形するホットプレス工法および本発明の摩擦材組成物の一態様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いずれかを好適に採用することができる。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℃以上、２００℃以下（好ましくは１６０℃）とし、成形圧力を１０ＭＰａ以上、４０ＭＰａ以下（好ましくは２０ＭＰａ）とし、成形時間を３分以上、１５分以下（好ましくは１０分）とすることで、本発明の摩擦材組成物の一態様を摩擦材に成形することができる。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以上、２００ＭＰａ以下（好ましくは１００ＭＰａ）とし、成形時間を５秒以上、６０秒以下（好ましくは１５秒）とすることで、本発明の摩擦材組成物の一態様を摩擦材に成形することができる。更に、必要に応じて、摩擦材の表面を研磨して摩擦面を形成する研磨工程を行ってもよい。 (Method for manufacturing friction material)
The friction material of this embodiment can be manufactured by a manufacturing method including a molding step of molding the friction material composition according to one embodiment of the present invention. The molding method and molding conditions in the molding step are not particularly limited as long as one embodiment of the friction material composition of the present invention can be molded into a predetermined shape, and methods known in the technical field can be adopted. For example, one embodiment of the friction material composition of the present invention can be molded by compacting with a press or the like. Examples of the press forming method include a hot press method in which an embodiment of the friction material composition of the present invention is heated and compacted, and a hot press method in which an embodiment of the friction material composition of the present invention is compacted at room temperature without heating. Any of the cold press methods for molding can be suitably employed. When molding is performed using the hot press method, for example, the molding temperature is 140°C or higher and 200°C or lower (preferably 160°C), the molding pressure is 10 MPa or higher and 40 MPa or lower (preferably 20 MPa), and the molding time is 3 minutes. As described above, by setting the time to 15 minutes or less (preferably 10 minutes), one embodiment of the friction material composition of the present invention can be molded into a friction material. In the case of molding by the cold press method, for example, the present invention can be achieved by setting the molding pressure to 50 MPa or more and 200 MPa or less (preferably 100 MPa) and the molding time to 5 seconds or more and 60 seconds or less (preferably 15 seconds). One embodiment of the friction material composition can be formed into a friction material. Furthermore, if necessary, a polishing step may be performed to polish the surface of the friction material to form a friction surface.
本態様の摩擦材は、本発明の一態様に係る摩擦材組成物を成形する成形工程を含む製造方法によって製造することができる。成形工程における成形方法および成形条件は、本発明の摩擦材組成物の一態様を所定の形状に成形することができる限り特に限定されず、当該技術分野で公知の方法を採用することができる。例えば、本発明の摩擦材組成物の一態様をプレス等で押し固めることにより成形することができる。プレスによる成形方法としては、本発明の摩擦材組成物の一態様を加熱して押し固めて成形するホットプレス工法および本発明の摩擦材組成物の一態様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いずれかを好適に採用することができる。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℃以上、２００℃以下（好ましくは１６０℃）とし、成形圧力を１０ＭＰａ以上、４０ＭＰａ以下（好ましくは２０ＭＰａ）とし、成形時間を３分以上、１５分以下（好ましくは１０分）とすることで、本発明の摩擦材組成物の一態様を摩擦材に成形することができる。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以上、２００ＭＰａ以下（好ましくは１００ＭＰａ）とし、成形時間を５秒以上、６０秒以下（好ましくは１５秒）とすることで、本発明の摩擦材組成物の一態様を摩擦材に成形することができる。更に、必要に応じて、摩擦材の表面を研磨して摩擦面を形成する研磨工程を行ってもよい。 (Method for manufacturing friction material)
The friction material of this embodiment can be manufactured by a manufacturing method including a molding step of molding the friction material composition according to one embodiment of the present invention. The molding method and molding conditions in the molding step are not particularly limited as long as one embodiment of the friction material composition of the present invention can be molded into a predetermined shape, and methods known in the technical field can be adopted. For example, one embodiment of the friction material composition of the present invention can be molded by compacting with a press or the like. Examples of the press forming method include a hot press method in which an embodiment of the friction material composition of the present invention is heated and compacted, and a hot press method in which an embodiment of the friction material composition of the present invention is compacted at room temperature without heating. Any of the cold press methods for molding can be suitably employed. When molding is performed using the hot press method, for example, the molding temperature is 140°C or higher and 200°C or lower (preferably 160°C), the molding pressure is 10 MPa or higher and 40 MPa or lower (preferably 20 MPa), and the molding time is 3 minutes. As described above, by setting the time to 15 minutes or less (preferably 10 minutes), one embodiment of the friction material composition of the present invention can be molded into a friction material. In the case of molding by the cold press method, for example, the present invention can be achieved by setting the molding pressure to 50 MPa or more and 200 MPa or less (preferably 100 MPa) and the molding time to 5 seconds or more and 60 seconds or less (preferably 15 seconds). One embodiment of the friction material composition can be formed into a friction material. Furthermore, if necessary, a polishing step may be performed to polish the surface of the friction material to form a friction surface.
＜３．摩擦部材＞
本発明の一態様に係る摩擦材を摩擦面として用いた摩擦部材も本発明の範疇に含まれる。摩擦部材としては、本発明の摩擦材の一態様のみを備える構成、または裏板としての金属板等の板状部材と本発明の摩擦材の一態様とを一体化した構成とすることができる。本態様の摩擦部材の効果、用途等は本発明の摩擦材組成物の一態様について説明したとおりであるのでここでは繰り返さない。 <3. Friction member>
A friction member using the friction material according to one embodiment of the present invention as a friction surface is also included in the scope of the present invention. The friction member may have a configuration including only one embodiment of the friction material of the present invention, or a configuration in which a plate-like member such as a metal plate as a back plate and one embodiment of the friction material of the present invention are integrated. . The effects, uses, etc. of the friction member of this embodiment are as described for one embodiment of the friction material composition of the present invention, so they will not be repeated here.
本発明の一態様に係る摩擦材を摩擦面として用いた摩擦部材も本発明の範疇に含まれる。摩擦部材としては、本発明の摩擦材の一態様のみを備える構成、または裏板としての金属板等の板状部材と本発明の摩擦材の一態様とを一体化した構成とすることができる。本態様の摩擦部材の効果、用途等は本発明の摩擦材組成物の一態様について説明したとおりであるのでここでは繰り返さない。 <3. Friction member>
A friction member using the friction material according to one embodiment of the present invention as a friction surface is also included in the scope of the present invention. The friction member may have a configuration including only one embodiment of the friction material of the present invention, or a configuration in which a plate-like member such as a metal plate as a back plate and one embodiment of the friction material of the present invention are integrated. . The effects, uses, etc. of the friction member of this embodiment are as described for one embodiment of the friction material composition of the present invention, so they will not be repeated here.
本態様の摩擦部材を、板状部材と本発明の摩擦材の一態様とが一体化した構成とする場合は、本発明の摩擦材の一態様と板状部材とをクランプ処理し、その後、熱処理することによって本発明の摩擦材の一態様と板状部材とを接着することができる。クランプ処理の条件は特に限定されないが、例えば、例えば、１８０℃、１ＭＰａ、１０分間である。また、クランプ処理後の熱処理の条件も特に限定されないが、例えば、１５０℃以上、２５０℃以下、５分以上、１８０分以下であり、好ましくは、２３０℃、３時間である。
When the friction member of this embodiment has a structure in which a plate-like member and one embodiment of the friction material of the present invention are integrated, one embodiment of the friction material of the present invention and the plate-like member are subjected to a clamping process, and then, One embodiment of the friction material of the present invention and the plate-like member can be bonded together by heat treatment. The conditions for the clamping treatment are not particularly limited, but are, for example, 180° C., 1 MPa, and 10 minutes. Further, the conditions for the heat treatment after the clamping treatment are also not particularly limited, but are, for example, 150° C. or more and 250° C. or less, 5 minutes or more and 180 minutes or less, preferably 230° C. and 3 hours.
〔まとめ〕
本発明の態様１に係る、摩擦材組成物は、摩擦材組成物中の銅の含有量が銅元素として０．５質量％未満である摩擦材組成物であり、無機充填材として、水酸化マグネシウムおよび単斜晶酸化ジルコニウムを含み、前記摩擦材組成物中の前記水酸化マグネシウムの含有量は、０．５質量％以上、１０質量％以下であり、且つ前記摩擦材組成物中の前記単斜晶酸化ジルコニウムの含有量は、５質量％以上、３５質量％以下である構成である。 〔summary〕
The friction material composition according to aspect 1 of the present invention is a friction material composition in which the content of copper in the friction material composition is less than 0.5% by mass as a copper element, and in which hydroxide is used as an inorganic filler. The friction material composition contains magnesium and monoclinic zirconium oxide, and the content of the magnesium hydroxide in the friction material composition is 0.5% by mass or more and 10% by mass or less, and The content of oblique crystal zirconium oxide is 5% by mass or more and 35% by mass or less.
本発明の態様１に係る、摩擦材組成物は、摩擦材組成物中の銅の含有量が銅元素として０．５質量％未満である摩擦材組成物であり、無機充填材として、水酸化マグネシウムおよび単斜晶酸化ジルコニウムを含み、前記摩擦材組成物中の前記水酸化マグネシウムの含有量は、０．５質量％以上、１０質量％以下であり、且つ前記摩擦材組成物中の前記単斜晶酸化ジルコニウムの含有量は、５質量％以上、３５質量％以下である構成である。 〔summary〕
The friction material composition according to aspect 1 of the present invention is a friction material composition in which the content of copper in the friction material composition is less than 0.5% by mass as a copper element, and in which hydroxide is used as an inorganic filler. The friction material composition contains magnesium and monoclinic zirconium oxide, and the content of the magnesium hydroxide in the friction material composition is 0.5% by mass or more and 10% by mass or less, and The content of oblique crystal zirconium oxide is 5% by mass or more and 35% by mass or less.
このような構成によれば、銅の含有量が銅元素として０．５質量％未満でありながらも、従来の摩擦材と比較して、高温域での高速制動時の効きおよび耐摩耗性に優れ、且つ常用の温度域においても十分な耐摩耗性を有し、さらに摩擦対面材との接触面に十分な防錆性を有する摩擦材を提供できるという効果を奏する。
According to such a structure, although the copper content is less than 0.5% by mass as a copper element, the effectiveness and wear resistance during high-speed braking in high temperature ranges are improved compared to conventional friction materials. It is possible to provide a friction material that has excellent and sufficient wear resistance even in a commonly used temperature range, and also has sufficient rust prevention properties on the contact surface with the friction facing material.
本発明の態様２に係る摩擦材組成物は、前記の態様１において、有機充填材として、非加硫エラストマーを含む構成としてもよい。
The friction material composition according to Aspect 2 of the present invention may be configured to include a non-vulcanized elastomer as the organic filler in Aspect 1 above.
このような構成によれば、常用の温度域における耐摩耗性および防錆性がさらに良化するという効果を奏する。
According to such a configuration, the effect is that the wear resistance and rust prevention properties in the normal temperature range are further improved.
本発明の態様３に係る摩擦材組成物は、前記の態様１または２において、前記摩擦材組成物中の前記水酸化マグネシウムの含有量は、０．８質量％以上、５質量％以下であり、且つ前記摩擦材組成物中の前記単斜晶酸化ジルコニウムの含有量は、２０質量％以上、３０質量％以下である構成としてもよい。
In the friction material composition according to aspect 3 of the present invention, in aspect 1 or 2, the content of the magnesium hydroxide in the friction material composition is 0.8% by mass or more and 5% by mass or less. , and the content of the monoclinic zirconium oxide in the friction material composition may be 20% by mass or more and 30% by mass or less.
このような構成によれば、高温域での高速制動時の効きおよび耐摩耗性がさらに良化するという効果を奏する。
According to such a configuration, the effectiveness and wear resistance during high-speed braking in a high temperature range are further improved.
本発明の態様４に係る摩擦材は、前記の態様１から３のいずれか１つの摩擦材組成物を成形してなる、構成である。
The friction material according to Aspect 4 of the present invention is formed by molding the friction material composition according to any one of Aspects 1 to 3 above.
本発明は上述した各実施形態に限定されるものではなく、請求項に示した範囲で種々の変更が可能であり、異なる実施形態にそれぞれ開示された技術的手段を適宜組み合わせて得られる実施形態についても本発明の技術的範囲に含まれる。
The present invention is not limited to the embodiments described above, and various modifications can be made within the scope of the claims, and embodiments obtained by appropriately combining technical means disclosed in different embodiments. are also included within the technical scope of the present invention.
＜摩擦材原料＞
実施例および比較例で用いた主要な摩擦材原料は以下のとおりである：
・単斜晶酸化ジルコニウム（単斜晶酸化ジルコニウム）：平均粒径１０μｍ以上
・安定化酸化ジルコニウム（安定化酸化ジルコニウム）：平均粒径１０μｍ以上
・水酸化マグネシウム：平均粒径４μｍまたは平均粒径１５μｍ
・酸化マグネシウム：平均粒径２μｍ
・非加硫ゴム（非加硫エラストマー）：粒状のＳＢＲ
上述した摩擦原料以外の原料は、当技術分野で通常用いられるものを使用した。 <Friction material raw materials>
The main friction material raw materials used in the Examples and Comparative Examples are as follows:
・Monoclinic zirconium oxide (monoclinic zirconium oxide): Average particle size of 10 μm or more ・Stabilized zirconium oxide (stabilized zirconium oxide): Average particle size of 10 μm or more ・Magnesium hydroxide: Average particle size of 4 μm or 15 μm
・Magnesium oxide: average particle size 2 μm
・Non-vulcanized rubber (non-vulcanized elastomer): Granular SBR
Raw materials other than the friction raw materials mentioned above were those commonly used in this technical field.
実施例および比較例で用いた主要な摩擦材原料は以下のとおりである：
・単斜晶酸化ジルコニウム（単斜晶酸化ジルコニウム）：平均粒径１０μｍ以上
・安定化酸化ジルコニウム（安定化酸化ジルコニウム）：平均粒径１０μｍ以上
・水酸化マグネシウム：平均粒径４μｍまたは平均粒径１５μｍ
・酸化マグネシウム：平均粒径２μｍ
・非加硫ゴム（非加硫エラストマー）：粒状のＳＢＲ
上述した摩擦原料以外の原料は、当技術分野で通常用いられるものを使用した。 <Friction material raw materials>
The main friction material raw materials used in the Examples and Comparative Examples are as follows:
・Monoclinic zirconium oxide (monoclinic zirconium oxide): Average particle size of 10 μm or more ・Stabilized zirconium oxide (stabilized zirconium oxide): Average particle size of 10 μm or more ・Magnesium hydroxide: Average particle size of 4 μm or 15 μm
・Magnesium oxide: average particle size 2 μm
・Non-vulcanized rubber (non-vulcanized elastomer): Granular SBR
Raw materials other than the friction raw materials mentioned above were those commonly used in this technical field.
〔実施例１〕
＜ブレーキパッドの作製＞
表１に示す配合比率に従って各原料を配合し、レーディゲミキサを使用して、常温（２０℃）で１０分間程度混合することで、摩擦材組成物を得た。なお、表１の各原料の配合量の単位は、摩擦材組成物中の質量％である。 [Example 1]
<Preparation of brake pad>
Each raw material was blended according to the blending ratio shown in Table 1, and mixed at room temperature (20° C.) for about 10 minutes using a Loedige mixer to obtain a friction material composition. Note that the unit of the blending amount of each raw material in Table 1 is mass % in the friction material composition.
＜ブレーキパッドの作製＞
表１に示す配合比率に従って各原料を配合し、レーディゲミキサを使用して、常温（２０℃）で１０分間程度混合することで、摩擦材組成物を得た。なお、表１の各原料の配合量の単位は、摩擦材組成物中の質量％である。 [Example 1]
<Preparation of brake pad>
Each raw material was blended according to the blending ratio shown in Table 1, and mixed at room temperature (20° C.) for about 10 minutes using a Loedige mixer to obtain a friction material composition. Note that the unit of the blending amount of each raw material in Table 1 is mass % in the friction material composition.
成形プレスを使用して、ホットプレス工法によって摩擦材組成物を加熱しつつ押し固めて成形して成形品を得た。ホットプレス工法による成形条件は、以下のとおりであった：
成形温度：１６０℃
成形圧力：２０ＭＰａ
成形時間：１０分間。 A molded article was obtained by heating and compacting the friction material composition using a hot press method using a molding press. The molding conditions for the hot press method were as follows:
Molding temperature: 160℃
Molding pressure: 20MPa
Molding time: 10 minutes.
成形温度：１６０℃
成形圧力：２０ＭＰａ
成形時間：１０分間。 A molded article was obtained by heating and compacting the friction material composition using a hot press method using a molding press. The molding conditions for the hot press method were as follows:
Molding temperature: 160℃
Molding pressure: 20MPa
Molding time: 10 minutes.
得られた成形品の表面を、研磨機を用いて研磨し摩擦面を形成して、摩擦材を得た。この摩擦材を使用して実施例１のブレーキパッドを作製し、高温試験および走行シミュレーション試験を行った。なお、実施例１で作製したブレーキパッドは、摩擦材の厚み１２．５ｍｍ、摩擦材投影面積５５ｃｍ２であった。
The surface of the obtained molded article was polished using a polishing machine to form a friction surface to obtain a friction material. A brake pad of Example 1 was prepared using this friction material, and a high temperature test and a driving simulation test were conducted. In addition, in the brake pad produced in Example 1, the thickness of the friction material was 12.5 mm, and the projected area of the friction material was 55 cm 2 .
〔実施例２～９〕
表１に示す配合比率に従って各原料を配合したこと以外は、実施例１と同様の方法で実施例２～９のブレーキパッドを作製した。 [Examples 2 to 9]
Brake pads of Examples 2 to 9 were produced in the same manner as in Example 1, except that each raw material was blended according to the blending ratio shown in Table 1.
表１に示す配合比率に従って各原料を配合したこと以外は、実施例１と同様の方法で実施例２～９のブレーキパッドを作製した。 [Examples 2 to 9]
Brake pads of Examples 2 to 9 were produced in the same manner as in Example 1, except that each raw material was blended according to the blending ratio shown in Table 1.
〔比較例１～１２〕
表２に示す配合比率に従って各原料を配合したこと以外は、実施例１と同様の方法で比較例１～１２のブレーキパッドを作製した。 [Comparative Examples 1 to 12]
Brake pads of Comparative Examples 1 to 12 were produced in the same manner as in Example 1, except that each raw material was blended according to the blending ratio shown in Table 2.
表２に示す配合比率に従って各原料を配合したこと以外は、実施例１と同様の方法で比較例１～１２のブレーキパッドを作製した。 [Comparative Examples 1 to 12]
Brake pads of Comparative Examples 1 to 12 were produced in the same manner as in Example 1, except that each raw material was blended according to the blending ratio shown in Table 2.
＜高温試験＞
ＡＭＳフェード試験（独自動車雑誌ａｕｔｏ ｍｏｔｏｒ ｕｎｄ ｓｐｏｒｔに掲載の評価条件：車速１３０ｋｍ／時間、最高ロータ温度６５０℃以上）を実施し、実施例１～９および比較例１～１２のブレーキパッドについて、以下の評価を行った。 <High temperature test>
An AMS fade test (evaluation conditions published in the German automobile magazine Auto Motor und Sport: vehicle speed 130 km/hour, maximum rotor temperature 650°C or higher) was conducted, and the brake pads of Examples 1 to 9 and Comparative Examples 1 to 12 were evaluated as follows. was evaluated.
ＡＭＳフェード試験（独自動車雑誌ａｕｔｏ ｍｏｔｏｒ ｕｎｄ ｓｐｏｒｔに掲載の評価条件：車速１３０ｋｍ／時間、最高ロータ温度６５０℃以上）を実施し、実施例１～９および比較例１～１２のブレーキパッドについて、以下の評価を行った。 <High temperature test>
An AMS fade test (evaluation conditions published in the German automobile magazine Auto Motor und Sport: vehicle speed 130 km/hour, maximum rotor temperature 650°C or higher) was conducted, and the brake pads of Examples 1 to 9 and Comparative Examples 1 to 12 were evaluated as follows. was evaluated.
ＡＭＳフェード試験は、（Ａ）製造されてから未使用（新品）のブレーキパッドおよび（Ｂ）市場走行履歴のあるブレーキパッドについてそれぞれ実施した。「（Ｂ）市場走行履歴のあるブレーキパッド」は、摩耗が進んだ状態および雨の中にさらされた状態を想定している。具体的には、新品での試験後のブレーキパッドおよびロータに、１分間にわたって合計１５Ｌの水をかけた後に、新品のブレーキパッドと同様の試験を実施した。各試験の最高ロータ温度は６５０～６７０℃であった。
The AMS fade test was conducted on (A) brake pads that have not been used since manufacture (new) and (B) brake pads that have a history of running on the market. "(B) Brake pads with a history of running on the market" are assumed to be in a state of advanced wear and a state of being exposed to rain. Specifically, a total of 15 L of water was poured over the brake pads and rotor after the new test for 1 minute, and then the same test as for the new brake pads was conducted. The maximum rotor temperature for each test was 650-670°C.
（最低摩擦係数）
ＡＭＳフェード試験時の最も低い摩擦係数を、下記の方法で測定した。
（最低摩擦係数の測定方法）
１制動中の最低トルクを用いて、各制動の摩擦係数をＪＩＳ Ｄ ０１０６記載の計算式で算出した。試験中で最も低い摩擦係数を最低摩擦係数とした。 (Minimum friction coefficient)
The lowest coefficient of friction during the AMS fade test was measured by the following method.
(Measurement method of minimum friction coefficient)
Using the lowest torque during one braking, the friction coefficient of each braking was calculated using the formula described in JIS D 0106. The lowest friction coefficient in the test was defined as the lowest friction coefficient.
ＡＭＳフェード試験時の最も低い摩擦係数を、下記の方法で測定した。
（最低摩擦係数の測定方法）
１制動中の最低トルクを用いて、各制動の摩擦係数をＪＩＳ Ｄ ０１０６記載の計算式で算出した。試験中で最も低い摩擦係数を最低摩擦係数とした。 (Minimum friction coefficient)
The lowest coefficient of friction during the AMS fade test was measured by the following method.
(Measurement method of minimum friction coefficient)
Using the lowest torque during one braking, the friction coefficient of each braking was calculated using the formula described in JIS D 0106. The lowest friction coefficient in the test was defined as the lowest friction coefficient.
最低摩擦係数の測定結果を、以下に示す基準に従って１～５の５段階のスコアで評価した。
５：比較例１に対して２０％を超えて良化
４：比較例１に対して１０％以上、２０％以下良化
３：比較例１と同じまたは同等
２：比較例１に対して１０％以上、２０％以下悪化
１：比較例１に対して２０％を超えて悪化
ここでは、評価対象のブレーキパッドの最低摩擦係数が比較例１のブレーキパッドの最低摩擦係数に対して１０％以上増加した場合に「良化」と評価し、評価対象のブレーキパッドの最低摩擦係数が比較例１のブレーキパッドの最低摩擦係数に対して１０％以上減少した場合に「悪化」と評価した。評価対象のブレーキパッドの最低摩擦係数の増減が比較例１のブレーキパッドの最低摩擦係数に対して１０％未満の場合は、比較例１と同じまたは同等と評価した。 The measurement results of the lowest coefficient of friction were evaluated on a five-point scale from 1 to 5 according to the criteria shown below.
5: More than 20% improvement compared to Comparative Example 1 4: 10% or more, 20% or less improvement compared to Comparative Example 1 3: Same or equivalent to Comparative Example 1 2: 10 compared to Comparative Example 1 % or more, 20% or less deterioration 1: Deterioration of more than 20% compared to Comparative Example 1 Here, the minimum friction coefficient of the brake pad to be evaluated is 10% or more compared to the minimum friction coefficient of the brake pad of Comparative Example 1. When the coefficient of friction increased, it was evaluated as "improved", and when the lowest friction coefficient of the brake pad to be evaluated decreased by 10% or more from the lowest friction coefficient of the brake pad of Comparative Example 1, it was evaluated as "deteriorated". If the increase or decrease in the minimum friction coefficient of the brake pad to be evaluated was less than 10% with respect to the minimum friction coefficient of the brake pad of Comparative Example 1, it was evaluated as the same or equivalent to Comparative Example 1.
５：比較例１に対して２０％を超えて良化
４：比較例１に対して１０％以上、２０％以下良化
３：比較例１と同じまたは同等
２：比較例１に対して１０％以上、２０％以下悪化
１：比較例１に対して２０％を超えて悪化
ここでは、評価対象のブレーキパッドの最低摩擦係数が比較例１のブレーキパッドの最低摩擦係数に対して１０％以上増加した場合に「良化」と評価し、評価対象のブレーキパッドの最低摩擦係数が比較例１のブレーキパッドの最低摩擦係数に対して１０％以上減少した場合に「悪化」と評価した。評価対象のブレーキパッドの最低摩擦係数の増減が比較例１のブレーキパッドの最低摩擦係数に対して１０％未満の場合は、比較例１と同じまたは同等と評価した。 The measurement results of the lowest coefficient of friction were evaluated on a five-point scale from 1 to 5 according to the criteria shown below.
5: More than 20% improvement compared to Comparative Example 1 4: 10% or more, 20% or less improvement compared to Comparative Example 1 3: Same or equivalent to Comparative Example 1 2: 10 compared to Comparative Example 1 % or more, 20% or less deterioration 1: Deterioration of more than 20% compared to Comparative Example 1 Here, the minimum friction coefficient of the brake pad to be evaluated is 10% or more compared to the minimum friction coefficient of the brake pad of Comparative Example 1. When the coefficient of friction increased, it was evaluated as "improved", and when the lowest friction coefficient of the brake pad to be evaluated decreased by 10% or more from the lowest friction coefficient of the brake pad of Comparative Example 1, it was evaluated as "deteriorated". If the increase or decrease in the minimum friction coefficient of the brake pad to be evaluated was less than 10% with respect to the minimum friction coefficient of the brake pad of Comparative Example 1, it was evaluated as the same or equivalent to Comparative Example 1.
（摩耗量）
ＡＭＳフェード試験後のブレーキパッドの摩耗量を、下記の方法で測定した。
（摩耗量の測定方法）
ＪＡＳＯ Ｃ４２７ ６．計測方法に準じて摩耗量を測定した。 (amount of wear)
The wear amount of the brake pad after the AMS fade test was measured by the following method.
(Method of measuring wear amount)
JASO C427 6. The amount of wear was measured according to the measurement method.
ＡＭＳフェード試験後のブレーキパッドの摩耗量を、下記の方法で測定した。
（摩耗量の測定方法）
ＪＡＳＯ Ｃ４２７ ６．計測方法に準じて摩耗量を測定した。 (amount of wear)
The wear amount of the brake pad after the AMS fade test was measured by the following method.
(Method of measuring wear amount)
JASO C427 6. The amount of wear was measured according to the measurement method.
試験後、ブレーキパッド１点につき８か所のパッド摩耗量を測定し、その平均値を「パッド平均摩耗量」とした。
After the test, the pad wear amount was measured at 8 locations for each brake pad, and the average value was defined as the "pad average wear amount."
摩耗量の測定結果を、以下に示す基準に従って１～５の５段階のスコアで評価した。
５：比較例１に対して２０％を超えて良化
４：比較例１に対して１０％以上、２０％以下良化
３：比較例１と同じまたは同等
２：比較例１に対して１０％以上、２０％以下悪化
１：比較例１に対して２０％を超えて悪化
ここでは、評価対象のブレーキパッドの平均摩耗量が比較例１のブレーキパッドの平均摩耗量に対して１０％以上減少した場合に「良化」と評価し、評価対象のブレーキパッドの平均摩耗量が比較例１のブレーキパッドの平均摩耗量に対して１０％以上増加した場合に「悪化」と評価した。評価対象のブレーキパッドの平均摩耗量の増減が比較例１のブレーキパッドの平均摩耗量に対して１０％未満の場合は、比較例１と同じまたは同等と評価した。 The measurement results of the amount of wear were evaluated using a five-level score from 1 to 5 according to the criteria shown below.
5: More than 20% improvement compared to Comparative Example 1 4: 10% or more, 20% or less improvement compared to Comparative Example 1 3: Same or equivalent to Comparative Example 1 2: 10 compared to Comparative Example 1 % or more, 20% or less deterioration 1: Deterioration of more than 20% compared to Comparative Example 1 Here, the average wear amount of the brake pad to be evaluated is 10% or more compared to the average wear amount of the brake pad of Comparative Example 1. If the average wear amount of the brake pad to be evaluated increased by 10% or more compared to the average wear amount of the brake pad of Comparative Example 1, it was evaluated as "deterioration". If the increase or decrease in the average wear amount of the brake pad to be evaluated was less than 10% with respect to the average wear amount of the brake pad of Comparative Example 1, it was evaluated as the same or equivalent to Comparative Example 1.
５：比較例１に対して２０％を超えて良化
４：比較例１に対して１０％以上、２０％以下良化
３：比較例１と同じまたは同等
２：比較例１に対して１０％以上、２０％以下悪化
１：比較例１に対して２０％を超えて悪化
ここでは、評価対象のブレーキパッドの平均摩耗量が比較例１のブレーキパッドの平均摩耗量に対して１０％以上減少した場合に「良化」と評価し、評価対象のブレーキパッドの平均摩耗量が比較例１のブレーキパッドの平均摩耗量に対して１０％以上増加した場合に「悪化」と評価した。評価対象のブレーキパッドの平均摩耗量の増減が比較例１のブレーキパッドの平均摩耗量に対して１０％未満の場合は、比較例１と同じまたは同等と評価した。 The measurement results of the amount of wear were evaluated using a five-level score from 1 to 5 according to the criteria shown below.
5: More than 20% improvement compared to Comparative Example 1 4: 10% or more, 20% or less improvement compared to Comparative Example 1 3: Same or equivalent to Comparative Example 1 2: 10 compared to Comparative Example 1 % or more, 20% or less deterioration 1: Deterioration of more than 20% compared to Comparative Example 1 Here, the average wear amount of the brake pad to be evaluated is 10% or more compared to the average wear amount of the brake pad of Comparative Example 1. If the average wear amount of the brake pad to be evaluated increased by 10% or more compared to the average wear amount of the brake pad of Comparative Example 1, it was evaluated as "deterioration". If the increase or decrease in the average wear amount of the brake pad to be evaluated was less than 10% with respect to the average wear amount of the brake pad of Comparative Example 1, it was evaluated as the same or equivalent to Comparative Example 1.
＜走行シミュレーション磨耗試験＞
ロサンゼルス（Ｌ．Ａ．）の市街地走行を模擬した台上試験機による試験（通称ＬＡＣＴシミュレーション試験）を行い、ブレーキパッドの推定寿命（パッド推定寿命）（マイル）を以下の式（１）から算出した。
パッド推定寿命（マイル）＝パッド厚み（ｍｍ）÷パッド平均摩耗量（ｍｍ）×試験の走行距離（マイル） ・・・（１）
ここで、「パッド厚み（ｍｍ）」は、ＬＡＣＴシミュレーション試験前のブレーキパッドの厚みであり、「パッド平均摩耗量（ｍｍ）」は、ＬＡＣＴシミュレーション試験前のブレーキパッドの平均摩耗量であり、その測定方法は、ＪＡＳＯ Ｃ４２７ ６．計測方法に準じた。 <Driving simulation wear test>
A test using a bench test machine simulating city driving in Los Angeles (L.A.) was conducted (commonly known as the LACT simulation test), and the estimated lifespan of the brake pads (estimated pad life) (in miles) was calculated using the following formula (1). did.
Estimated pad life (miles) = Pad thickness (mm) ÷ Average pad wear (mm) x Test mileage (miles) ... (1)
Here, "pad thickness (mm)" is the thickness of the brake pad before the LACT simulation test, and "pad average wear amount (mm)" is the average wear amount of the brake pad before the LACT simulation test. The measurement method is JASO C427 6. According to the measurement method.
ロサンゼルス（Ｌ．Ａ．）の市街地走行を模擬した台上試験機による試験（通称ＬＡＣＴシミュレーション試験）を行い、ブレーキパッドの推定寿命（パッド推定寿命）（マイル）を以下の式（１）から算出した。
パッド推定寿命（マイル）＝パッド厚み（ｍｍ）÷パッド平均摩耗量（ｍｍ）×試験の走行距離（マイル） ・・・（１）
ここで、「パッド厚み（ｍｍ）」は、ＬＡＣＴシミュレーション試験前のブレーキパッドの厚みであり、「パッド平均摩耗量（ｍｍ）」は、ＬＡＣＴシミュレーション試験前のブレーキパッドの平均摩耗量であり、その測定方法は、ＪＡＳＯ Ｃ４２７ ６．計測方法に準じた。 <Driving simulation wear test>
A test using a bench test machine simulating city driving in Los Angeles (L.A.) was conducted (commonly known as the LACT simulation test), and the estimated lifespan of the brake pads (estimated pad life) (in miles) was calculated using the following formula (1). did.
Estimated pad life (miles) = Pad thickness (mm) ÷ Average pad wear (mm) x Test mileage (miles) ... (1)
Here, "pad thickness (mm)" is the thickness of the brake pad before the LACT simulation test, and "pad average wear amount (mm)" is the average wear amount of the brake pad before the LACT simulation test. The measurement method is JASO C427 6. According to the measurement method.
ＡＭＳフェード試験と同様に走行シミュレーション磨耗試験も、実施例１～９および比較例１～１２のブレーキパッドを用いて、（Ａ）製造されてから未使用（新品）のブレーキパッドおよび（Ｂ）市場走行履歴のあるブレーキパッドについてそれぞれ実施した。「（Ｂ）市場走行履歴のあるブレーキパッド」は、新品での試験後のブレーキパッドおよびロータに、１分間にわたって合計１５Ｌの水をかけた後に、新品のブレーキパッドと同様の試験を実施した。各試験の平均ロータ温度は１００～２００℃であった。
Similar to the AMS fade test, the driving simulation wear test was also conducted using the brake pads of Examples 1 to 9 and Comparative Examples 1 to 12. Tests were conducted for each brake pad that had a history of running. "(B) Brake pads with a history of running on the market" were subjected to the same test as new brake pads after a total of 15 L of water was poured over the brake pads and rotor for 1 minute after testing as new brake pads. The average rotor temperature for each test was 100-200°C.
パッド推定寿命の算出結果を、以下に示す基準に従って１～５の５段階のスコアで評価した。
５：比較例１に対して２０％を超えて良化
４：比較例１に対して１０％以上、２０％以下良化
３：比較例１と同じまたは同等
２：比較例１に対して１０％以上、２０％以下悪化
１：比較例１に対して２０％を超えて悪化
ここでは、評価対象のブレーキパッドのパッド推定寿命が比較例１のブレーキパッドのパッド推定寿命に対して１０％以上増加した場合に「良化」と評価し、評価対象のブレーキパッドのパッド推定寿命が比較例１のブレーキパッドのパッド推定寿命に対して１０％以上減少した場合に「悪化」と評価した。評価対象のブレーキパッドのパッド推定寿命の増減が比較例１のブレーキパッドのパッド推定寿命に対して１０％未満の場合は、比較例１と同じまたは同等と評価した。 The calculation results of the estimated pad lifespan were evaluated on a five-point scale from 1 to 5 according to the criteria shown below.
5: More than 20% improvement compared to Comparative Example 1 4: 10% or more, 20% or less improvement compared to Comparative Example 1 3: Same or equivalent to Comparative Example 1 2: 10 compared to Comparative Example 1 % or more, 20% or less deterioration 1: Deterioration of more than 20% compared to Comparative Example 1 Here, the estimated pad life of the brake pad to be evaluated is 10% or more of the pad estimated life of the brake pad of Comparative Example 1. If the estimated pad life of the brake pad to be evaluated decreased by 10% or more compared to the estimated pad life of the brake pad of Comparative Example 1, it was evaluated as "deterioration". If the increase or decrease in the estimated pad life of the brake pad to be evaluated was less than 10% with respect to the estimated pad life of the brake pad of Comparative Example 1, it was evaluated as the same or equivalent to Comparative Example 1.
５：比較例１に対して２０％を超えて良化
４：比較例１に対して１０％以上、２０％以下良化
３：比較例１と同じまたは同等
２：比較例１に対して１０％以上、２０％以下悪化
１：比較例１に対して２０％を超えて悪化
ここでは、評価対象のブレーキパッドのパッド推定寿命が比較例１のブレーキパッドのパッド推定寿命に対して１０％以上増加した場合に「良化」と評価し、評価対象のブレーキパッドのパッド推定寿命が比較例１のブレーキパッドのパッド推定寿命に対して１０％以上減少した場合に「悪化」と評価した。評価対象のブレーキパッドのパッド推定寿命の増減が比較例１のブレーキパッドのパッド推定寿命に対して１０％未満の場合は、比較例１と同じまたは同等と評価した。 The calculation results of the estimated pad lifespan were evaluated on a five-point scale from 1 to 5 according to the criteria shown below.
5: More than 20% improvement compared to Comparative Example 1 4: 10% or more, 20% or less improvement compared to Comparative Example 1 3: Same or equivalent to Comparative Example 1 2: 10 compared to Comparative Example 1 % or more, 20% or less deterioration 1: Deterioration of more than 20% compared to Comparative Example 1 Here, the estimated pad life of the brake pad to be evaluated is 10% or more of the pad estimated life of the brake pad of Comparative Example 1. If the estimated pad life of the brake pad to be evaluated decreased by 10% or more compared to the estimated pad life of the brake pad of Comparative Example 1, it was evaluated as "deterioration". If the increase or decrease in the estimated pad life of the brake pad to be evaluated was less than 10% with respect to the estimated pad life of the brake pad of Comparative Example 1, it was evaluated as the same or equivalent to Comparative Example 1.
＜耐錆評価＞
さび固着試験を、ＪＩＳ Ｄ４４１４－２：１９９８ 「さび固着試験方法（浸漬法）」に準拠して行い、さび固着力を測定した。 <Rust resistance evaluation>
A rust adhesion test was conducted in accordance with JIS D4414-2:1998 "Rust adhesion test method (immersion method)" to measure the rust adhesion strength.
さび固着試験を、ＪＩＳ Ｄ４４１４－２：１９９８ 「さび固着試験方法（浸漬法）」に準拠して行い、さび固着力を測定した。 <Rust resistance evaluation>
A rust adhesion test was conducted in accordance with JIS D4414-2:1998 "Rust adhesion test method (immersion method)" to measure the rust adhesion strength.
ＡＭＳフェード試験および走行シミュレーション磨耗試験と同様にさび固着試験も、実施例１～９および比較例１～１２のブレーキパッドを用いて、（Ａ）製造されてから未使用（新品）のブレーキパッドおよび（Ｂ）市場走行履歴のあるブレーキパッドについてそれぞれ実施した。「（Ｂ）市場走行履歴のあるブレーキパッド」は、新品での走行シミュレーション磨耗試験後のブレーキパッドおよびロータに、１分間にわたって合計１５Ｌの水をかけた後に、新品のブレーキパッドと同様の試験を実施した。
Similar to the AMS fade test and the driving simulation wear test, the rust adhesion test was also conducted using the brake pads of Examples 1 to 9 and Comparative Examples 1 to 12. (B) Tests were conducted on brake pads with a history of running on the market. "(B) Brake pads with a history of market driving" are brand new brake pads and rotors that have undergone a driving simulation wear test, and a total of 15L of water is poured over them for one minute, and then the same test as new brake pads is performed. carried out.
さび固着力の測定結果に基づき、錆によるパッドはりつきの度合いを、以下に示す基準に従って１～５の５段階のスコアで評価した。
５：比較例１に対して３０％を超えて良化
４：比較例１に対して１５％以上、３０％以下良化
３：比較例１と同じまたは同等
２：比較例１に対して１５％以上、３０％以下悪化
１：比較例１に対して３０％を超えて悪化
ここでは、評価対象のブレーキパッドのさび固着力が比較例１のブレーキパッドのさび固着力に対して１５％以上減少した場合に「良化」と評価し、評価対象のブレーキパッドのさび固着力が比較例１のブレーキパッドのさび固着力に対して１５％以上増加した場合に「悪化」と評価した。評価対象のブレーキパッドのさび固着力の増減が比較例１のブレーキパッドのさび固着力に対して１５％未満の場合は、比較例１と同じまたは同等と評価した。 Based on the measurement results of the rust adhesion strength, the degree of pad adhesion due to rust was evaluated on a five-point scale from 1 to 5 according to the criteria shown below.
5: More than 30% improvement compared to Comparative Example 1 4: 15% or more, 30% or less improvement compared to Comparative Example 1 3: Same or equivalent to Comparative Example 1 2: 15 compared to Comparative Example 1 % or more, 30% or less deterioration 1: Deterioration of more than 30% compared to Comparative Example 1 Here, the rust fixing force of the brake pad to be evaluated is 15% or more compared to the rust fixing force of the brake pad of Comparative Example 1. When the rust adhesion force of the brake pad to be evaluated increased by 15% or more compared to the rust adhesion force of the brake pad of Comparative Example 1, it was evaluated as "improved". If the increase or decrease in the rust fixing force of the brake pad to be evaluated was less than 15% of the rust fixing force of the brake pad of Comparative Example 1, it was evaluated as the same or equivalent to Comparative Example 1.
５：比較例１に対して３０％を超えて良化
４：比較例１に対して１５％以上、３０％以下良化
３：比較例１と同じまたは同等
２：比較例１に対して１５％以上、３０％以下悪化
１：比較例１に対して３０％を超えて悪化
ここでは、評価対象のブレーキパッドのさび固着力が比較例１のブレーキパッドのさび固着力に対して１５％以上減少した場合に「良化」と評価し、評価対象のブレーキパッドのさび固着力が比較例１のブレーキパッドのさび固着力に対して１５％以上増加した場合に「悪化」と評価した。評価対象のブレーキパッドのさび固着力の増減が比較例１のブレーキパッドのさび固着力に対して１５％未満の場合は、比較例１と同じまたは同等と評価した。 Based on the measurement results of the rust adhesion strength, the degree of pad adhesion due to rust was evaluated on a five-point scale from 1 to 5 according to the criteria shown below.
5: More than 30% improvement compared to Comparative Example 1 4: 15% or more, 30% or less improvement compared to Comparative Example 1 3: Same or equivalent to Comparative Example 1 2: 15 compared to Comparative Example 1 % or more, 30% or less deterioration 1: Deterioration of more than 30% compared to Comparative Example 1 Here, the rust fixing force of the brake pad to be evaluated is 15% or more compared to the rust fixing force of the brake pad of Comparative Example 1. When the rust adhesion force of the brake pad to be evaluated increased by 15% or more compared to the rust adhesion force of the brake pad of Comparative Example 1, it was evaluated as "improved". If the increase or decrease in the rust fixing force of the brake pad to be evaluated was less than 15% of the rust fixing force of the brake pad of Comparative Example 1, it was evaluated as the same or equivalent to Comparative Example 1.
＜結果＞
高速試験における各評価結果、走行シミュレーション磨耗試験における評価結果および耐錆評価における評価結果を、表１および表２に示した。
<Results>
The evaluation results in the high-speed test, the evaluation results in the driving simulation wear test, and the evaluation results in the rust resistance evaluation are shown in Tables 1 and 2.
高速試験における各評価結果、走行シミュレーション磨耗試験における評価結果および耐錆評価における評価結果を、表１および表２に示した。
The evaluation results in the high-speed test, the evaluation results in the driving simulation wear test, and the evaluation results in the rust resistance evaluation are shown in Tables 1 and 2.
表１に示すとおり、実施例１～９のブレーキパッドは、無機充填材として水酸化マグネシウムおよび単斜晶酸化ジルコニウムを特定量含有することにより、比較例１のブレーキパッドと比較して、高温域での高速制動時の効きおよび耐摩耗性に優れ、且つ常用の温度域においても十分な耐摩耗性を有し、さらに摩擦対面材との接触面に十分な防錆性を有していることが確認された。また、実施例１～８と実施例９との比較から、非加硫エラストマーとして非加硫ゴムを配合することによって、常用の温度域での耐摩耗性および防錆性がより向上することが確認された。
As shown in Table 1, the brake pads of Examples 1 to 9 contain specific amounts of magnesium hydroxide and monoclinic zirconium oxide as inorganic fillers, so that they are more effective at high temperatures than the brake pad of Comparative Example 1. It has excellent effectiveness and wear resistance during high-speed braking, and has sufficient wear resistance even in the normal temperature range, and has sufficient rust prevention on the contact surface with the friction facing material. was confirmed. Furthermore, from a comparison between Examples 1 to 8 and Example 9, it was found that by blending non-vulcanized rubber as the non-vulcanized elastomer, the wear resistance and rust prevention properties in the temperature range of normal use are further improved. confirmed.
摩擦材中の単斜晶酸化ジルコニウムは、高温域での高速制動により発生する高熱によって酸化マグネシウム（摩擦材中の水酸化マグネシウムが脱水によって変化したもの）と融合することで、安定化酸化ジルコニウムとなる。摩擦面に形成された安定化酸化ジルコニウムの被膜は、摩擦面を保護することによって高温域の耐摩耗性を向上させ、ひいては高温域の摩擦係数（μ）を向上させる。
The monoclinic zirconium oxide in the friction material fuses with magnesium oxide (magnesium hydroxide in the friction material is changed by dehydration) due to the high heat generated by high-speed braking in a high temperature range, and becomes stabilized zirconium oxide. Become. The stabilized zirconium oxide film formed on the friction surface protects the friction surface, thereby improving the wear resistance in the high temperature range and, in turn, improving the coefficient of friction (μ) in the high temperature range.
これに対して、単斜晶酸化ジルコニウムの代わりに安定化酸化ジルコニウムを配合した比較例１２のブレーキパッドは、常用の温度域での耐摩耗性が悪化した。これは、安定化酸化ジルコニウムのモース硬度が高いため、攻撃性が高く、摩耗してしまうためであると考えられた。水酸化マグネシウムの代わりに酸化マグネシウムを配合した比較例１１のブレーキパッドも同様に、酸化マグネシウムのモース硬度が高いため、常用の温度域における耐摩耗性が低下し、パッド推定寿命が悪化した。
On the other hand, the brake pad of Comparative Example 12, in which stabilized zirconium oxide was blended instead of monoclinic zirconium oxide, had deteriorated wear resistance in the normal temperature range. This is thought to be because stabilized zirconium oxide has a high Mohs hardness, which makes it highly aggressive and causes wear. Similarly, the brake pad of Comparative Example 11 in which magnesium oxide was blended instead of magnesium hydroxide had a high Mohs' hardness of magnesium oxide, so the wear resistance in the normal temperature range decreased and the estimated life of the pad deteriorated.
これらのことから、摩擦材組成物に配合された単斜晶酸化ジルコニウムと水酸化マグネシウムとが高温域での高速制動により発生する高熱によって反応することによって、摩擦面に安定化酸化ジルコニウムの被膜が適宜形成されることが、常用の温度域での耐摩耗性および防錆性の向上と高温域での高速制動時の効きおよび耐摩耗性の向上とを両立させる上で重要であると考えられた。
Based on these facts, the monoclinic zirconium oxide and magnesium hydroxide blended into the friction material composition react with the high heat generated by high-speed braking in a high temperature range, resulting in a stabilized zirconium oxide coating being formed on the friction surface. Appropriate formation is considered to be important in achieving both improvement in wear resistance and rust prevention in the normal temperature range and improvement in high-speed braking effectiveness and wear resistance in the high-temperature range. Ta.
本発明の一態様に係る摩擦材組成物および摩擦材は、自動車等の車両の制動装置における摩擦部材に好適に利用することができる。
The friction material composition and friction material according to one embodiment of the present invention can be suitably used in a friction member in a braking device for a vehicle such as an automobile.
Claims (4)
- 摩擦材組成物中の銅の含有量が銅元素として０．５質量％未満である摩擦材組成物であり、
無機充填材として、水酸化マグネシウムおよび単斜晶酸化ジルコニウムを含み、
前記摩擦材組成物中の前記水酸化マグネシウムの含有量は、０．５質量％以上、１０質量％以下であり、且つ
前記摩擦材組成物中の前記単斜晶酸化ジルコニウムの含有量は、５質量％以上、３５質量％以下である、摩擦材組成物。 A friction material composition in which the content of copper as a copper element is less than 0.5% by mass,
Contains magnesium hydroxide and monoclinic zirconium oxide as inorganic fillers,
The content of the magnesium hydroxide in the friction material composition is 0.5% by mass or more and 10% by mass or less, and the content of the monoclinic zirconium oxide in the friction material composition is 5% by mass or more. A friction material composition having a content of not less than 35% by mass and not more than 35% by mass. - 有機充填材として、非加硫エラストマーを含む、請求項１に記載の摩擦材組成物。 The friction material composition according to claim 1, comprising a non-vulcanized elastomer as the organic filler.
- 前記摩擦材組成物中の前記水酸化マグネシウムの含有量は、０．８質量％以上、５質量％以下であり、且つ
前記摩擦材組成物中の前記単斜晶酸化ジルコニウムの含有量は、２０質量％以上、３０質量％以下である、請求項１に記載の摩擦材組成物。 The content of the magnesium hydroxide in the friction material composition is 0.8% by mass or more and 5% by mass or less, and the content of the monoclinic zirconium oxide in the friction material composition is 20% by mass or more. The friction material composition according to claim 1, which has a content of % by mass or more and 30% by mass or less. - 請求項１から３のいずれか１項に記載の摩擦材組成物を成形してなる摩擦材。 A friction material formed by molding the friction material composition according to any one of claims 1 to 3.
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| JP2022117151A JP2024014374A (en) | 2022-07-22 | 2022-07-22 | Friction material composition and friction material |
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Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2000160135A (en) * | 1998-11-25 | 2000-06-13 | Hitachi Chem Co Ltd | Friction material composition and friction material using the composition |
| JP2020073650A (en) * | 2019-10-31 | 2020-05-14 | 日立化成株式会社 | Friction material composition, friction material and friction member using friction material composition |
| JP2020183465A (en) * | 2019-04-27 | 2020-11-12 | 日清紡ブレーキ株式会社 | Under layer composition for disk brake pad and disk brake pad including the composition |
| US20210071729A1 (en) * | 2017-12-19 | 2021-03-11 | Federal-Mogul Friction Products Gmbh | Hybrid friction lining material, brake linings produced from same and method for producing same |
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- 2022-07-22 JP JP2022117151A patent/JP2024014374A/en active Pending
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Patent Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2000160135A (en) * | 1998-11-25 | 2000-06-13 | Hitachi Chem Co Ltd | Friction material composition and friction material using the composition |
| US20210071729A1 (en) * | 2017-12-19 | 2021-03-11 | Federal-Mogul Friction Products Gmbh | Hybrid friction lining material, brake linings produced from same and method for producing same |
| JP2020183465A (en) * | 2019-04-27 | 2020-11-12 | 日清紡ブレーキ株式会社 | Under layer composition for disk brake pad and disk brake pad including the composition |
| JP2020073650A (en) * | 2019-10-31 | 2020-05-14 | 日立化成株式会社 | Friction material composition, friction material and friction member using friction material composition |
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