| abstract |
(57) [Summary] (with correction) [PROBLEMS] To provide an additive for improving the low-temperature fluidity of a heavy middle distillate containing a relatively large amount of paraffin. A comprises the following copolymers A and B, additive: copolymer of lower olefins and vinyl esters containing A) following structural units; A1) formula -CH 2 -CR 1 R 2 - [ R 1 and R 2 is H or methyl], a divalent structural unit of from 85 to 97 mol%; [R 3 is C 6 -C 16 -alkyl] divalent structural unit of at least 3 mol%; B) copolymers containing the following structural units: % By weight; B1) Formulas B1a to B1b [X represents O or NR 4, a, b is 0 to 1, a + b is 1] bivalent structural units 40 to 60 mol% of; B2) formula -H 2 C-CHR 5 B3) 0 to 20 mol% of a divalent structural unit derived from a polyolefin; [R 4 is an alkyl, alkenylalkoxyalkyl group, R 5 Is an alkyl group, and the polyolefin has 35 to 35 carbon atoms. 0]. |