An object of the present invention is to provide a friction material that applies low load on the environment and exhibits improved friction characteristics, particularly improved fade resistance and wear resistance. The friction material of the invention contains a fibrous base material, a friction modifier, and a binder, wherein the copper content is 0.5% by mass or less in terms of elemental copper, and lithium carbonate is contained.

In the friction material used for the disc brake pad, which is manufactured by forming a non-asbestos-organic (NAO) friction material composition, it is an object of this invention to provide the friction material that satisfies the laws and regulations with respect to the amount of the copper component contained therein and at the same time inhibits the generation of the just-before-stopping noise. In the friction material used for the disc brake pad, which is manufactured by forming a non-asbestos-organic (NAO) friction material composition that contains the binder, the fiber base, the inorganic friction modifier, the organic friction modifier, and the lubricant but does not contain the copper component, the friction material composition contains 0.5-5 weight %, relative to the entire amount of the friction material composition, of the fluoropolymer particle with the average particle diameter of 10-1000 μm as the lubricant and 15-35 weight %, relative to the entire amount of the friction material composition, of the zirconium oxide with the average particle diameter of 1-8 μm as the inorganic friction modifier.

A wet friction material includes a base including a matrix of fibers and filler particles embedded in the matrix of fibers; a binder embedded in an interior of the base; and a quaternary ammonium salt containing coating on an outer surface of the base. The quaternary ammonium salt containing coating can include a quaternary ammonium salt and a solution binder.

The present invention provides a friction material and a brake pad having excellent wear resistance while exhibiting a high friction coefficient under high-temperature and high-speed conditions. A friction material containing: 40 mass % or more and 80 mass % or less of a matrix containing at least one kind selected from the group consisting of Ni and Fe; 10 mass % or more and 30 mass % or less of inorganic particles containing zircon particles, titania particles, and mullite particles; and 10 mass % or more and 30 mass % or less of a lubricant containing at least one kind selected from the group consisting of graphite, molybdenum disulfide, boron nitride and calcium fluoride, wherein a content of the zircon particles is 30 vol % or more and 36 vol % or less, a content of the titania particles is 30 vol % or more and 36 vol % or less, and a content of the mullite particles is 30 vol % or more and 36 vol % or less with respect to a total content of 100 vol % of the zircon particles, the titania particles, and the mullite particles.

A complex oxide powder contains cerium, zirconium, and aluminum and, has a specific surface area of 0.5 m.sup.2/g or more and 10 m.sup.2/g or less.

Provided is an iron oxide powder for a brake friction material which can be suitably used in a brake friction material that is less likely to cause problems regarding brake squealing and that provides superior braking performance. The iron oxide powder for a brake friction material according to a first embodiment of the present invention is characterized by having a sulfur content of 150 ppm or less as measured by combustion ion chromatography, and a saturation magnetization of 20 emu/g or less. The iron oxide powder for a brake friction material according to a second embodiment of the present invention is characterized by having an average particle size of 1.0 μm or more, a chlorine content of 150 ppm or less as measured by combustion ion chromatography, and a saturation magnetization of 20 emu/g or less.

A friction material presents a friction-generating surface and a bonding surface opposite the friction-generating surface. The friction material includes unbranched fiber having a diameter of from 0.5 to 50 μm and a length of from 0.2 to 15 mm, branched fiber having a diameter of from 1 to 50 μm, and a resin disposed throughout the friction material. The friction material is substantially free of particles and defines a plurality of pores having a pore size distribution with a D10 value of from 5 to 15 μm, a D50 value of from 15 to 30 μm, and a D90 value of from 30 to 60 μm.

A friction member according to an embodiment is a friction material having a copper content of less than 5 wt %, the friction material including a titanic acid salt having a content of 1 wt % or more and 8 wt % or less, a cryolite powder having a content of 0.5 wt % or more and 5 wt % or less, and an iron oxide powder having a median diameter of 15 to 30 μm (D50) and a content of 1 wt % or more and 10 wt % or less.

The friction material composition has superior conductivity of a friction material, superior adherence of a coating during powder coating, superior film formation of coating and superior abrasion resistance without containing copper having serious environmental effects, the friction material composition includes a binder, an organic filler material, an inorganic filler material, and a fibrous substrate material, wherein the friction material composition contains 8 to 35 mass % of ferrosoferric oxide (Fe.sub.3O.sub.4).

The invention relates to a method for applying sand to the inner radius of drum brake linings comprising the following steps: a) rolling a UV-curing adhesive onto the inner radius of a drum brake lining, b) applying a frictional grain, such as zircon sand, to the adhesive layer, c) removing the frictional grain not retained by the adhesive from the lining surface, and d) curing the coating by means of UV radiation.