FUEL OIL ADDITIVE AND FUEL OIL COMPOSITION

摘要

PROBLEM TO BE SOLVED: To provide a fuel oil additive having excellent cleaning performance for a fuel system and a combustion chamber of an internal combustion engine even under a frequent severe operation condition. SOLUTION: The objective additive for fuel oil is composed of a polymer A containing >=75 wt.% methacrylate (a1) as a constituent unit and having a solubility parameter (SP value) of 8.5-12.5. The number-average molecular weight of the polymer A is 300-5,000, the residual weight at 200 deg.C is 25-75% and the residual weight at 300 deg.C is <=3% in a differential thermogravimetry measured by raising the temperature from 30 deg.C at a rate of 10 deg.C/min.