Flow improver additive for distillate fuels, and concentrate thereof

Claim 2

A process for improving the cold flow of distillate fuel oil comprising incorporating therein a polyoxyalkylene ester, ether, ester/ether or mixtures thereof which contain at least two C 10 to C 30 linear saturated alkyl group and a polyoxyalkylene glycol of molecular weight 100 to 5000 the alkyl group of said polyoxyalkylene glycol containing from 1 to 4 carbon atoms.

Claim 3

A process according to claim 1 in which the distillate fuel oil boils in the range of 200°C±50°C to 340°C±20°C.

Claim 4

A process according to claim 1 or claim 2 wherein the polyoxyalkylene glycol is of molecular weight 200 to 2,000.

Claim 5

A process according to claim 1 or claim 2 wherein the C 10 to C 30 linear saturated alkyl group is stearic and/or behenic.

Claim 6

A process according to any of the preceding claims wherein the polyoxyalkylene glycol is a polyethylene glycol.

Claim 7

A process according to claim 5 wherein the glycol is a mixture of polyethylene and polypropylene glycols.

Claim 8

A process according to any one of the preceding claims comprising also incorporating into the distillate fuel oil a lube oil pour depressant.

Claim 9

A process for improving the cold flow properties of distillate fuels comprising incorporating therein a combination of (i) an ester, ether, ester/ether or mixtures thereof of the general formula where R and R 1 are the same or different and may be the alkyl group being linear and saturated and containing 10 to 30 carbon atoms and A is a polyoxyalkylene glycol of molecular weight 100 to 5,000 wherein the alkylene group contains 1 to 4 carbon atoms and (ii) an ethylene copolymer wax crystal growth inhibitor or a C 30 -C 300 oil soluble polar nitrogen compound wax crystal growth inhibitor being an amine and/or amide salt and/or ester/amide of a carboxylic acid having 1 to 4 carboxylic acid groups or an anhydride thereof. 9. A process according to claim 8 wherein the ethylene copolymer is an ethylene vinyl acetate copolymer.

Claim 10

A process according to claim 8 or 9 comprising incorporating from 20 to 40 wt.% of the polyoxyalkylene glycol and 80 to 60 wt.% of the ethylene copolymer or the C 30 to C 300 oil soluble polar nitrogen compound based on the total weight of additive in the fuel.

Claim 11

A process according to claim 8 wherein the polar nitrogen compound is the reaction product of a C 12 ―C 40 secondary amine and phthalic anhydride.

Claim 12

A process according any of the preceding claims wherein the polyoxyalkylene ester, ether or ester/ether is incorporated into the distillate fuel as an oil solution containing from 3 to 75 wt.% of a ester, ether, ester/ether or mixtures thereof of the general formula where R and R 1 are the same or different and may be the alkyl group being linear and saturated and containing 10 to 30 carbon atoms, and A is a polyoxyalkylene glycol of molecular weight 100 to 5,000 wherein the alkylene group contains from 1 to 4 carbon atoms.

Claim 13

A process according to claim 12 in which the concentrate also contains an ethylene copolymer wax crystal growth inhibitor or a C 30 -C 300 oil soluble polar nitrogen compound wax crystal growth inhibitor being an amine and/or amide salt and/or ester/amide of a carboxylic acid having 1 to 4 carboxylic acid groups or an anhydride thereof.

Claim 14

A process according to claim 13 in which the concentrate contains from 60 to 80 wt.% based on the total additive content of the concentrate of the ethylene copolymer or C 30 -C 300 oil soluble polar nitrogen compound.