Preparation of oil resisting rubbers

Oil-resistant rubber is prepared by treating oxygenated derivatives of rubber so as to form linkages between the molecules either by vulcanization or by heating so as to cause the evolution of water. The derivatives are formed by treating rubber either with (1) oxygen in presence of acetic anhydride or acetic acid to which an oxidation catalyst such as cobalt nitrate or linoleate may be added, and hydrolysing the product to replace ester groups by hydroxyl groups; (2) lead tetracetate or lead p tetrabenzoate, the product being afterwards hydrolysed; or (3) a per-acid such as perbenzoic or monoperphthalic acid. Specifications 417,912 and 462,627 are referred to.