| 摘要 |
A nitrile rubber composition which contains 5 to 50 parts by weight of carbon black, 5 to 60 parts by weight of graphite having a mean particle diameter of 5μm or less, 5 to 50 parts by weight of a conductive carbon material other than these, and further contains, as antioxidants, 1 to 5 parts by weight of an alkylated diphenylamine consisting of a reaction product of diphenylamine with styrene and 2,4,4-trimethylpentene and 0.5 to 2.5 parts by weight of N,N'-di-2-naphthyl-p-phenylenediamine or dilauryl thiodipropionate, each quantity being relative to 100 parts by weight of nitrile rubber. This nitrile rubber composition can yield a vulcanization-molded product that not only keeps characteristics as conductive material but also satisfies characteristics requisite to an oil seal for a rolling bearing for an automobile or the like, namely, muddy water resistance, sealing properties and low-torque properties, and that exhibits a suppressed rubber volume change even when has been exposed to an antifreezing agent and then washed with water. |
