Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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 fibers 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.

Abstract: Multilayer silver halide color photographic element comprising a support having thereon at least a blue sensitive silver halide emulsion layer containing a yellow dye-forming coupler, at least a green-sensitive silver halide emulsion layer containing a magenta dye-forming coupler, and at least a red-sensitive silver halide emulsion layer containing a cyan dye-forming coupler, said red-sensitive layer containing a non-diffusible, cyan dye-forming magenta masking coupler.

Abstract: Multilayer silver halide color photographic element comprising a support having thereon at least a blue sensitive silver halide emulsion layer containing a yellow dye-forming coupler, at least a green-sensitive silver halide emulsion layer containing a magenta dye-forming coupler, and at least a red-sensitive silver halide emulsion layer containing a cyan dye-forming coupler, said red-sensitive layer or a gelatin interlayer adjacent said red-sensitive layer containing a non-diffusible, non-coupling magenta colored azo dye.

Abstract: A process for preparation of 2-equivalent 4-arylthio-5-pyrazolone magenta couplers comprises the steps of:(i) reacting a 4-equivalent 5-pyrazolone magenta coupler and a diaryldisulfide compound in the presence of 1,8-diazabicyclo-[5,4,0]-undecen-7-ene and an organic solvent to obtain a reaction product between 4-arylthio-5-pyrazolone magenta coupler and 1,8-diazabicyclo-[5,4,0]-undecen-7-ene, and(ii) converting the reaction product with an inorganic acid into the 4-arylthio-5-pyrazolone magenta coupler.The reaction product between the 4-arylthio-5-pyrazolone magenta coupler and the 1,8-diazabicyclo-[5,4,0]-undecen-7-ene is easily formed in high yield and purity. This reaction product, which is insoluble in the reaction solvent, can be easily isolated from the reaction mixture and converted by acidification into the 2-equivalent 4-arylthio-5-pyrazolone magenta coupler in high yield and purity.