Additives for fuel oils

A fuel oil composition comprising (a) a major amount of a fuel oil;

• and (b) 10-500 ppm by weight based on the weight of the fuel oil of a compound being the product of the 1,4-addition reaction of (i) ammonia, a primary or secondary hydrocarbyl-substituted amine or a mixture thereof to (ii) a species containing one or more α,β-unsaturated carbonyl groups, wherein the compound includes at least one hydrocarbyl group containing at least 10 carbon atoms;
• and
• wherein species (ii) is of formula A-B,
• wherein A comprises a moiety of general formula I which is bonded to B via the carbonyl group:
• wherein R3 represents hydrogen, C1 to C8 hydrocarbyl group, or C(O)OR5,
• wherein R4 represents C1 to C8 hydrocarbyl group, or —C(O)OR5, where R5 represents a hydrocarbyl group, containing from 1 to 40 carbon atoms,
• wherein B independently represents —NR6R7 or —OR8,
• wherein R6 and R7 each independently represent hydrogen or a hydrocarbyl group, containing up to 40 carbon atoms which group is optionally substituted or terminated with one or more substituents selected from —OR9, —NR10R11, or a combination thereof, and/or interrupted by one or more oxygen atoms and/or —N(R12)— groups, where R9, R10, R11 and R12 each independently represent hydrogen, a hydrocarbyl group containing up to 20 carbon atoms, or a moiety of general formula I;
• and,
• wherein R8 independently represents hydrogen or a hydrocarbyl group, containing up to 40 carbon atoms which group is optionally substituted or terminated with one or more substituents of —NR14R15, and/or interrupted by one or more —N(R16)— groups, where R14, R15 and R16 each independently represent hydrogen, a hydrocarbyl group containing up to 20 carbon atoms, or a moiety of general formula I as defined herein.