Composition to improve cold flow properties of fuel oils

1. A composition, comprising:

at least 90% by weight of the composition of a biodiesel fuel oil; and

from 0.1 to 0.50% by weight of a copolymer mixture, comprising:

i) a polyalkyl(meth)acrylate polymer having a number average molecular weight Mn of from 1000 to 10000 g/mol and a polydispersity Mw/Mn of from 1 to 8; and

ii) an ethylene vinyl acetate copolymer comprising in polymerized form an alkyl (meth)acrylate having 1 to 30 carbon atoms in the alkyl residue;

wherein

the ethylene vinyl acetate copolymer is a graft copolymer comprising an ethylene vinyl acetate copolymer as a graft base and the alkyl (meth)acrylate having 1 to 30 carbon atoms in the alkyl residue as a graft layer;

a weight ratio of the polyalkyl(meth)acrylate polymer i) to the ethylene vinyl acetate copolymer ii) is in the range of from 15:1 to 1:1;

the polyalkyl(meth)acrylate polymer comprises:

(a) 0 to 40% by weight of polymerized units derived from one or more alkyl(meth)acrylate monomers of formula (I):

wherein

R is hydrogen or methyl, and

R 1 is a linear, branched or cyclic alkyl residue with 1 to 6 carbon atoms,

(b) at least 10% by weight of polymerized units derived from one or more alkyl(meth)acrylate monomers of formula (II):

wherein

R is hydrogen or methyl, and

R 2 is a linear, branched or cyclic alkyl residue with 7 to 15 carbon atoms, and

(c) 0 to 40% by weight of polymerized units derived from one or more alkyl(meth)acrylate monomers of formula (III):

wherein

R is hydrogen or methyl, and

R 3 is a linear, branched or cyclic alkyl residue with 16-40 carbon atoms;

the ethylene vinyl acetate copolymer comprises in polymerized form 0.5 to 60 weight % of vinyl acetate; and

the alkyl (meth)acrylate having 1 to 30 carbon atoms in the alkyl residue as the graft layer comprises in polymerized form from 30 to 90 weight % of an alkyl (meth)acrylate having 7 to 15 carbon atoms in the alkyl residue.

2. The composition of claim 1 , wherein said polyalkyl(meth)acrylate polymer i) comprises at least 50% by weight of polymerized units derived from the alkyl (meth)acrylate monomers of formula (II).

3. The composition of claim 1 , wherein the polydispersity Mw/Mn of said polyalkyl(meth)acrylate polymer i) is in the range of from 1.1 to 5.

4. The composition of claim 1 , wherein said polyalkyl(meth)acrylate polymer i) further comprises in polymerized form a hydroxyl-containing monomer, a (meth)acrylate of an ether alcohol, or a mixture thereof.

5. The composition of claim 1 , wherein said ethylene vinyl acetate copolymer ii) comprises in polymerized form from 2 to 30 weight % of vinyl acetate.

6. The composition of claim 1 , wherein said ethylene vinyl acetate copolymer ii) comprises in polymerized form from 1 to 60 weight % of ethylene.

7. The composition of claim 1 , wherein said ethylene vinyl acetate copolymer ii) further comprises in polymerized form up to 20 weight % of at least one additional comonomer.

8. The composition of claim 1 , wherein said ethylene vinyl acetate copolymer ii) has a number average molecular weight Mn of from 1000 to 120 000 g/mol.

9. The composition of claim 1 , wherein the alkyl (meth)acrylate having 1 to 30 carbon atoms in the alkyl residue as graft layer comprises in polymerized form from 60 to 80 weight % of an alkyl (meth)acrylate having 7 to 15 carbon atoms in the alkyl residue.

10. The composition of claim 1 , wherein a weight ratio of graft base to graft layer in said ethylene vinyl acetate copolymer ii) is in the range of from 1:1 to 1:8.

11. The composition of claim 1 , further comprising a mineral oil.

12. The composition of claim 1 , wherein said biodiesel fuel oil comprises a fatty acid ester derived from a monohydric alcohol having 1 to 4 carbon atoms.

13. The composition of claim 12 , wherein said biodiesel oil comprises at least 10% by weight of a fatty acid ester derived from methanol, ethanol, or both, and a saturated fatty acid.

14. The composition of claim 1 , wherein the copolymer mixture consists of i) and ii).

15. The composition of claim 1 , wherein the polyalkyl(meth)acrylate polymer comprises 0.1 to 30% by weight of polymerized units derived from one or more alkyl(meth)acrylate monomers of formula (I).

16. The composition of claim 1 , wherein the polyalkyl(meth)acrylate polymer comprises 25 to 100% by weight of polymerized units derived from one or more alkyl(meth)acrylate monomers of formula (II).

17. The composition of claim 1 , wherein the polyalkyl(meth)acrylate polymer comprises 0.1 to 30% by weight of polymerized units derived from one or more alkyl(meth)acrylate monomers of formula (III).

18. The composition of claim 1 , wherein the polyalkyl(meth)acrylate polymer comprises:

0.5 to 20% by weight of polymerized units derived from one or more alkyl(meth)acrylate monomers of formula (I);

70 to 99% by weight of polymerized units derived from one or more alkyl(meth)acrylate monomers of formula (II); and

0.5 to 20% by weight of polymerized units derived from one or more alkyl(meth)acrylate monomers of formula (III).

19. The composition of claim 1 , which comprises at least 98% by weight of the composition of a biodiesel fuel oil.