To provide a fuel oil fluidity improver which reduces the clogging point and the fluidity point with good balance and additionally excels in the solubility in a gas oil and a heavy oil, and a fuel oil composition comprising the same.
A fuel oil fluidity improver comprises a polymer hydride obtained by hydrogenating a polymer composed of butadiene and isoprene as the major component with a weight ratio of the units derived from isoprene to the units derived from butadiene in this polymer of 80/20 to 5/95 or a fuel oil fluidity improver comprises the polymer hydride and a polyoxyalkylene glycol having a polyalkylene glycol part and a chain alkyl part with a weight ratio of the former to the latter of 1/99 to 99/1. A fuel oil composition is obtained by adding this fuel oil fluidity improver to a gas oil or a heavy oil.
OISHI MAKOTO
FUKUMOTO MASAHIRO
