FLUIDITY IMPROVER

摘要

PROBLEM TO BE SOLVED: To obtain a fluidity improver with which a low-temperature fluidity can be greatly improved by addition of a smaller amount of the fluidity improver than that of a conventional fluidity improver even for a fuel oil having a narrow boiling point range of distillation and which has excellent solubility in a base oil and no problem of oil through property. SOLUTION: This fluidity improver comprises a copolymer (A) having a unit derived from ethylene (a) and a vinyl monomer (b) containing an alicyclic group and an ester group as an essential constituent unit.