A friction material, such as those belonging to the NAO or LS classes. The friction material is substantially free from copper and includes non-spherical particles in the form of powders and/or fibres each constituted by a preferably ferrous metallic core and by an at least partial coating of core formed at least partially or totally by tin and/or tin compounds, such as intermetallic Fe—Sn compounds.

A friction material comprising: (a) at least one lubricant, wherein the at least one lubricant includes an amount of graphite, and wherein at least about 30 percent by weight of the graphite has a particle size of greater than about 500 microns using a sieve analysis; (b) at least one metal containing constituent for imparting reinforcement, thermal conductivity, and/or friction when the friction material is brought into contact with a movable member, wherein the at least one metal containing constituent includes iron and an iron containing compound; (c) a micro-particulated material; (d) one or more filler materials; (e) optionally at least one processing aid; (f) a balance being an organic binder, wherein the organic binder has less than 1 percent by weight of free phenol; wherein the friction material is free of asbestos and substantially devoid of copper.

The invention relates to a brake disk (3), which has at least one thermal conduction layer (4, 6) with a thermal conductivity and specific thermal resistivity that can be graduated, the thermal conduction layer consisting of at least two different materials or of a varying layer thickness, thereby graduating the thermal conductivity or the thermal resistivity within the thermal conduction layer.

The invention relates to a method for improving braking performance of a microporous friction material under wet conditions. A hydrophobic agent is added into the components for preparing microporous friction material. The microporous friction material is prepared from the following raw materials in percentage by weight: 10%-20% of nano-silica modified phenolic resin, 4%-14% of butadiene-styrene rubber, 5%-15% of glass fiber, 2%-11% of aramid pulp, 4%-15% of aluminum borate whisker, 4%-10% of hydrophobic agent and 3%-8% of calcium silicate, 1%-8% of artificial graphite, 2%-8% of coke, 2%-7% of mica, 5%-10% of cryolite and 4%-10% of diatomite.

[Object]

To provide the friction material for the disc brake pad such as an automobile, which is manufactured by forming the NAO friction material composition, enabling to restrain the brake vibration during braking in a high temperature.

[Means to Resolve]

In the friction material, which is manufactured by forming the NAO friction material composition that does not contain the copper component but contains the binder, the fiber base, the organic friction modifier, the inorganic friction modifier, and the lubricant, the friction material composition contains 5-9 weight % of the binder relative to the entire amount of the friction material composition, 1-4 weight % of the silicone rubber modified phenol resin as a part of the binder relative to the entire amount of the friction material composition, 1-4 weight % of a cashew dust as the organic friction modifier relative to the entire amount of the friction material composition, 0.5-3 weight % of a fused silica with the average particle diameter of 15-40 μm as the inorganic friction modifier relative to the entire amount of the friction material composition, and 0.1-2 weight % of the electromelting zirconium silicate beads with the average particle diameter of 10-30 μm as the inorganic friction modifier relative to the entire amount of the friction material composition.

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.

An asbestos-free friction material includes inorganic and/or organic and/or metallic fibers, at least one binder, at least one friction modifier or lubricant, at least one filler or abrasive and a carbonaceous material constituted by a microstructure. The microstructure is in the form of flakes or scales of micrometric planar dimensions and of nanometric thickness consisting of a substantially pure graphene mono- or multilayers, preferably pre-blended with at least part of the organic binder.

Calcium silicate powders are provided. The calcium silicate powders comprise porous calcium silicate particles and an additive, the additive being at least partially penetrated into the pores of the particles. The additive is present in an amount of between 1.5 and 50%w, wherein %w is the weight ratio, expressed as percentage, of the dry weight of the additive over the dry weight of the combination of the calcium silicate particles and additive.

The invention relates to a method for improving braking performance of a microporous friction material under wet conditions. A hydrophobic agent is added into the components for preparing microporous friction material. The microporous friction material is prepared from the following raw materials in percentage by weight: 10%-20% of nano-silica modified phenolic resin, 4%-14% of butadiene-styrene rubber, 5%-15% of glass fiber, 2%-11% of aramid pulp, 4%-15% of aluminum borate whisker, 4%-10% of hydrophobic agent and 3%-8% of calcium silicate, 1%-8% of artificial graphite, 2%-8% of coke, 2%-7% of mica, 5%-10% of cryolite and 4%-10% of diatomite.

A friction material composition containing a binder, an organic filler, an inorganic filler and a fibrous base material, wherein the friction material composition either contains no copper as an element or has a content of copper as an element that does not exceed 0.5% by mass, contains α-alumina and γ-alumina in a mass ratio within a range from 1:20 to 1:5, contains a silicone-containing phenol resin, contains 20 to 35% by mass of a titanate salt, contains 3 to 7% by mass of a graphite having a median diameter of 1 to 30 μm, and contains antimony trisulfide.