FRICTION MATERIAL COMPOSITION

PROBLEM TO BE SOLVED: To obtain a friction material composition that has high thermal conductivity and can combine wear resistance during high temperature braking and securement of friction coefficient during normal time and fading time, without containing copper doubtful to be harmful to an environment.SOLUTION: A friction material composition includes: a binder; an organic filler; an inorganic filler; and a fiber substrate, in which the friction material composition does not contain copper as an element or has a content of copper of 0.5 mass% or smaller, magnesium oxide is contained, and graphite and coke are contained, the graphite and the coke are contained in a combination of a crude material and a fine material, the crude material has an average particle size of 150 to 600 μm, and the fine material has an average particle size of 100 μm or smaller.SELECTED DRAWING: None 【課題】環境に対して有害であると疑われている銅を含有せずとも、熱伝導性が高く、高温制動時の耐摩耗性、通常時とフェード時の摩擦係数の確保を両立する摩擦材組成物を得ること。【解決手段】結合材、有機充填材、無機充填材および繊維基材を含む摩擦材組成物であって、前記摩擦材組成物中に元素として銅を含まず、または銅の含有量が０．５質量％以下であり、酸化マグネシウムを含有し、かつ黒鉛およびコークスを含有し、前記黒鉛および前記コークスは、粗粒物と微粒物の組合せで含有し、粗粒物は平均粒子径が１５０〜６００μｍであり、微粒物は平均粒子径が１００μｍ以下である摩擦材組成物とする。【選択図】なし