Blown bitumen prodn accelerated by - naphthenic acids

摘要

Prodn. of blown bitumen for roofing felts is accelerated by adding 5-20 (pref. 10-15) weight % liquid naphthenic acids of 200-500 (350-400) mol. wt. to molten bitumen distillate before start of blowing, and then carrying out bitumen oxidation at 230-280 degrees C pref, 250 degrees C with an air:bitumen ratio of 0.2-1 pref. 0.35 m. 3 air/min. and ton bitumen. Pref. naphthenic acids used are obtained by neutralisation of vacuum distillates.