| 摘要 |
<p>Prods. are obtd. from petroleum distillates and/or solvent extracts of petroleum distillates having a viscosity-gravity constant (VGC, ASTM D 2140) of >0.85 (pref. >0.90) by blowing with O2 (pref. as air) and fractionating to recover at least one fraction boiling in the 320-420 degrees C range at a pressure of 760 mm Hg. The process can be used to produce a light "treatment oil" with high oxidative stability (b.p. 320-375 degrees C), a mid-range "treatment oil" (b.p. 375-420 degrees C), and a heavy fraction with an initial b.p. of >=400 degrees C for use as an additive for gramophone disc moulding compsns., giving an increased rate of prodn. and better sound reproduction. The initial distillate or extract is suitably a lube oil distillate or extract with an av. mol. wt. of 150-600 (pref. 200-500). Air blowing is pref. effected in the presence of 0.01-2 wt% of Cr, Co, Ni, Fe, Cu, Mn or Zn in the form of an oxide or an org. salt (pref. a naphthenate, acetate, propionate or butyrate), pref. for >=7 hr. The org. matl. entrained in the off-gas is pref. condensed and recycled. The above three fractions can be recovered from the same fractionation column, but are pref. recovered from separate operations, each preceded by air blowing.</p> |
