Friction material of improved wear properties - for disc brakes, esp. for rail vehicles, contains phenol! resin, asbestos fibres and silicon carbide

摘要

Friction material suitable for the shoes of disc brakes for rail vehicles comprises (by wt.) 25-35 pts. of a phenolic resin binder, 2-12 pts. of a carbon cpd., 35-50 pts. of asbestos fibres and 0.4-3 pts. of silicon carbide. In addition, it may contain 2-10 pts. of resin formed from the shell of ground cashew nuts (pref. fully cured) 0.5-12 pts. of nitrile rubber, and/or 1-25 pts. of an inert filter (esp. 0.5-10 pts. of shredded tyre material and 0.5-15 pts. of barytes). Pref. C cpd. is graphic C or is C black with 95% of particle size 74 mu; amt. pref. is 4-8 pts. wt. Pref. friction material has compsn.: 29 pts. phenolic resin binder, 6 pts. graphitic carbon, 41 pts. asbestos fibre (esp. chrysotile) and 0.6 pts. SiC (pref. 95% of particle size 44 mu). It may also contain 6 pts. of fully cured particles of resin from ground cashew-nut shells, 6 pts. of nitrile rubber and a filler based on 6 pts. of shredded tyres and 6 pts. barytes.