Friction material
[Object] The present invention provides a friction material used for a disc brake pad, which is manufactured by forming a non-asbestos-organic (NAO) friction material composition that does not contain a copper component, which provides an excellent wear resistance and a highly stable braking effectiveness even after being subjected to a history of high temperatures and high loads. [Means to Resolve] The friction material composition for the friction material molding containing, as an inorganic friction modifier, 10-40 weight % of a monoclinic zirconium oxide with an average particle diameter of 1-8 μm relative to the total amount of the friction material composition, 1.5 weight % or more of a resilient graphitic carbon as a carbon type lubricant relative to the total amount of the friction material composition, and a calcined coke also as a carbon type lubricant, where total amount of the resilient graphitic carbon and the calcined coke is 2-8 weight % relative to the total amount of the friction material composition and a weight ratio of the resilient graphitic carbon and the calcined coke is 4:6-8:2. It is preferable that the friction material composition contains 2-6 weight % of the layered mineral particle as the inorganic friction modifier relative to the total amount of the friction material composition and that the layered mineral particle is mica.
1. A friction material used for a disc brake pad, which is manufactured by forming a non-asbestos-organic (NAO) friction material composition that does not contain a copper component, wherein
said friction material composition contains as an inorganic friction modifier, 10-40 weight % of a monoclinic zirconium oxide with an average particle diameter of 1-8 μm relative to the total amount of the friction material composition,
1.5 weight % or more of a resilient graphitic carbon as a carbon type lubricant relative to the total amount of the friction material composition and a calcined coke also as a carbon type lubricant, where a total amount of the resilient graphitic carbon and the calcined coke is 2-8 weight % relative to the total amount of the friction material composition, and
a weight ratio of the resilient graphitic carbon and the calcined coke is 4:6-8:2.
2. The friction material according to claim 1 , wherein
the friction material composition contains 2-6 weight % of a layered mineral particle as the inorganic friction modifier relative to the total amount of the friction material composition.
3. The friction material according to claim 2 , wherein
the layered mineral particle is mica.